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diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
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+++ b/clang/lib/Sema/SemaChecking.cpp
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+//===--- SemaChecking.cpp - Extra Semantic Checking -----------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements extra semantic analysis beyond what is enforced
+// by the C type system.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Sema/Initialization.h"
+#include "clang/Sema/Sema.h"
+#include "clang/Sema/SemaInternal.h"
+#include "clang/Sema/Initialization.h"
+#include "clang/Sema/ScopeInfo.h"
+#include "clang/Analysis/Analyses/FormatString.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/CharUnits.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/DeclObjC.h"
+#include "clang/AST/ExprCXX.h"
+#include "clang/AST/ExprObjC.h"
+#include "clang/AST/EvaluatedExprVisitor.h"
+#include "clang/AST/DeclObjC.h"
+#include "clang/AST/StmtCXX.h"
+#include "clang/AST/StmtObjC.h"
+#include "clang/Lex/Preprocessor.h"
+#include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/Support/raw_ostream.h"
+#include "clang/Basic/TargetBuiltins.h"
+#include "clang/Basic/TargetInfo.h"
+#include "clang/Basic/ConvertUTF.h"
+#include <limits>
+using namespace clang;
+using namespace sema;
+
+SourceLocation Sema::getLocationOfStringLiteralByte(const StringLiteral *SL,
+ unsigned ByteNo) const {
+ return SL->getLocationOfByte(ByteNo, PP.getSourceManager(),
+ PP.getLangOpts(), PP.getTargetInfo());
+}
+
+/// Checks that a call expression's argument count is the desired number.
+/// This is useful when doing custom type-checking. Returns true on error.
+static bool checkArgCount(Sema &S, CallExpr *call, unsigned desiredArgCount) {
+ unsigned argCount = call->getNumArgs();
+ if (argCount == desiredArgCount) return false;
+
+ if (argCount < desiredArgCount)
+ return S.Diag(call->getLocEnd(), diag::err_typecheck_call_too_few_args)
+ << 0 /*function call*/ << desiredArgCount << argCount
+ << call->getSourceRange();
+
+ // Highlight all the excess arguments.
+ SourceRange range(call->getArg(desiredArgCount)->getLocStart(),
+ call->getArg(argCount - 1)->getLocEnd());
+
+ return S.Diag(range.getBegin(), diag::err_typecheck_call_too_many_args)
+ << 0 /*function call*/ << desiredArgCount << argCount
+ << call->getArg(1)->getSourceRange();
+}
+
+/// CheckBuiltinAnnotationString - Checks that string argument to the builtin
+/// annotation is a non wide string literal.
+static bool CheckBuiltinAnnotationString(Sema &S, Expr *Arg) {
+ Arg = Arg->IgnoreParenCasts();
+ StringLiteral *Literal = dyn_cast<StringLiteral>(Arg);
+ if (!Literal || !Literal->isAscii()) {
+ S.Diag(Arg->getLocStart(), diag::err_builtin_annotation_not_string_constant)
+ << Arg->getSourceRange();
+ return true;
+ }
+ return false;
+}
+
+ExprResult
+Sema::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
+ ExprResult TheCallResult(Owned(TheCall));
+
+ // Find out if any arguments are required to be integer constant expressions.
+ unsigned ICEArguments = 0;
+ ASTContext::GetBuiltinTypeError Error;
+ Context.GetBuiltinType(BuiltinID, Error, &ICEArguments);
+ if (Error != ASTContext::GE_None)
+ ICEArguments = 0; // Don't diagnose previously diagnosed errors.
+
+ // If any arguments are required to be ICE's, check and diagnose.
+ for (unsigned ArgNo = 0; ICEArguments != 0; ++ArgNo) {
+ // Skip arguments not required to be ICE's.
+ if ((ICEArguments & (1 << ArgNo)) == 0) continue;
+
+ llvm::APSInt Result;
+ if (SemaBuiltinConstantArg(TheCall, ArgNo, Result))
+ return true;
+ ICEArguments &= ~(1 << ArgNo);
+ }
+
+ switch (BuiltinID) {
+ case Builtin::BI__builtin___CFStringMakeConstantString:
+ assert(TheCall->getNumArgs() == 1 &&
+ "Wrong # arguments to builtin CFStringMakeConstantString");
+ if (CheckObjCString(TheCall->getArg(0)))
+ return ExprError();
+ break;
+ case Builtin::BI__builtin_stdarg_start:
+ case Builtin::BI__builtin_va_start:
+ if (SemaBuiltinVAStart(TheCall))
+ return ExprError();
+ break;
+ case Builtin::BI__builtin_isgreater:
+ case Builtin::BI__builtin_isgreaterequal:
+ case Builtin::BI__builtin_isless:
+ case Builtin::BI__builtin_islessequal:
+ case Builtin::BI__builtin_islessgreater:
+ case Builtin::BI__builtin_isunordered:
+ if (SemaBuiltinUnorderedCompare(TheCall))
+ return ExprError();
+ break;
+ case Builtin::BI__builtin_fpclassify:
+ if (SemaBuiltinFPClassification(TheCall, 6))
+ return ExprError();
+ break;
+ case Builtin::BI__builtin_isfinite:
+ case Builtin::BI__builtin_isinf:
+ case Builtin::BI__builtin_isinf_sign:
+ case Builtin::BI__builtin_isnan:
+ case Builtin::BI__builtin_isnormal:
+ if (SemaBuiltinFPClassification(TheCall, 1))
+ return ExprError();
+ break;
+ case Builtin::BI__builtin_shufflevector:
+ return SemaBuiltinShuffleVector(TheCall);
+ // TheCall will be freed by the smart pointer here, but that's fine, since
+ // SemaBuiltinShuffleVector guts it, but then doesn't release it.
+ case Builtin::BI__builtin_prefetch:
+ if (SemaBuiltinPrefetch(TheCall))
+ return ExprError();
+ break;
+ case Builtin::BI__builtin_object_size:
+ if (SemaBuiltinObjectSize(TheCall))
+ return ExprError();
+ break;
+ case Builtin::BI__builtin_longjmp:
+ if (SemaBuiltinLongjmp(TheCall))
+ return ExprError();
+ break;
+
+ case Builtin::BI__builtin_classify_type:
+ if (checkArgCount(*this, TheCall, 1)) return true;
+ TheCall->setType(Context.IntTy);
+ break;
+ case Builtin::BI__builtin_constant_p:
+ if (checkArgCount(*this, TheCall, 1)) return true;
+ TheCall->setType(Context.IntTy);
+ break;
+ case Builtin::BI__sync_fetch_and_add:
+ case Builtin::BI__sync_fetch_and_add_1:
+ case Builtin::BI__sync_fetch_and_add_2:
+ case Builtin::BI__sync_fetch_and_add_4:
+ case Builtin::BI__sync_fetch_and_add_8:
+ case Builtin::BI__sync_fetch_and_add_16:
+ case Builtin::BI__sync_fetch_and_sub:
+ case Builtin::BI__sync_fetch_and_sub_1:
+ case Builtin::BI__sync_fetch_and_sub_2:
+ case Builtin::BI__sync_fetch_and_sub_4:
+ case Builtin::BI__sync_fetch_and_sub_8:
+ case Builtin::BI__sync_fetch_and_sub_16:
+ case Builtin::BI__sync_fetch_and_or:
+ case Builtin::BI__sync_fetch_and_or_1:
+ case Builtin::BI__sync_fetch_and_or_2:
+ case Builtin::BI__sync_fetch_and_or_4:
+ case Builtin::BI__sync_fetch_and_or_8:
+ case Builtin::BI__sync_fetch_and_or_16:
+ case Builtin::BI__sync_fetch_and_and:
+ case Builtin::BI__sync_fetch_and_and_1:
+ case Builtin::BI__sync_fetch_and_and_2:
+ case Builtin::BI__sync_fetch_and_and_4:
+ case Builtin::BI__sync_fetch_and_and_8:
+ case Builtin::BI__sync_fetch_and_and_16:
+ case Builtin::BI__sync_fetch_and_xor:
+ case Builtin::BI__sync_fetch_and_xor_1:
+ case Builtin::BI__sync_fetch_and_xor_2:
+ case Builtin::BI__sync_fetch_and_xor_4:
+ case Builtin::BI__sync_fetch_and_xor_8:
+ case Builtin::BI__sync_fetch_and_xor_16:
+ case Builtin::BI__sync_add_and_fetch:
+ case Builtin::BI__sync_add_and_fetch_1:
+ case Builtin::BI__sync_add_and_fetch_2:
+ case Builtin::BI__sync_add_and_fetch_4:
+ case Builtin::BI__sync_add_and_fetch_8:
+ case Builtin::BI__sync_add_and_fetch_16:
+ case Builtin::BI__sync_sub_and_fetch:
+ case Builtin::BI__sync_sub_and_fetch_1:
+ case Builtin::BI__sync_sub_and_fetch_2:
+ case Builtin::BI__sync_sub_and_fetch_4:
+ case Builtin::BI__sync_sub_and_fetch_8:
+ case Builtin::BI__sync_sub_and_fetch_16:
+ case Builtin::BI__sync_and_and_fetch:
+ case Builtin::BI__sync_and_and_fetch_1:
+ case Builtin::BI__sync_and_and_fetch_2:
+ case Builtin::BI__sync_and_and_fetch_4:
+ case Builtin::BI__sync_and_and_fetch_8:
+ case Builtin::BI__sync_and_and_fetch_16:
+ case Builtin::BI__sync_or_and_fetch:
+ case Builtin::BI__sync_or_and_fetch_1:
+ case Builtin::BI__sync_or_and_fetch_2:
+ case Builtin::BI__sync_or_and_fetch_4:
+ case Builtin::BI__sync_or_and_fetch_8:
+ case Builtin::BI__sync_or_and_fetch_16:
+ case Builtin::BI__sync_xor_and_fetch:
+ case Builtin::BI__sync_xor_and_fetch_1:
+ case Builtin::BI__sync_xor_and_fetch_2:
+ case Builtin::BI__sync_xor_and_fetch_4:
+ case Builtin::BI__sync_xor_and_fetch_8:
+ case Builtin::BI__sync_xor_and_fetch_16:
+ case Builtin::BI__sync_val_compare_and_swap:
+ case Builtin::BI__sync_val_compare_and_swap_1:
+ case Builtin::BI__sync_val_compare_and_swap_2:
+ case Builtin::BI__sync_val_compare_and_swap_4:
+ case Builtin::BI__sync_val_compare_and_swap_8:
+ case Builtin::BI__sync_val_compare_and_swap_16:
+ case Builtin::BI__sync_bool_compare_and_swap:
+ case Builtin::BI__sync_bool_compare_and_swap_1:
+ case Builtin::BI__sync_bool_compare_and_swap_2:
+ case Builtin::BI__sync_bool_compare_and_swap_4:
+ case Builtin::BI__sync_bool_compare_and_swap_8:
+ case Builtin::BI__sync_bool_compare_and_swap_16:
+ case Builtin::BI__sync_lock_test_and_set:
+ case Builtin::BI__sync_lock_test_and_set_1:
+ case Builtin::BI__sync_lock_test_and_set_2:
+ case Builtin::BI__sync_lock_test_and_set_4:
+ case Builtin::BI__sync_lock_test_and_set_8:
+ case Builtin::BI__sync_lock_test_and_set_16:
+ case Builtin::BI__sync_lock_release:
+ case Builtin::BI__sync_lock_release_1:
+ case Builtin::BI__sync_lock_release_2:
+ case Builtin::BI__sync_lock_release_4:
+ case Builtin::BI__sync_lock_release_8:
+ case Builtin::BI__sync_lock_release_16:
+ case Builtin::BI__sync_swap:
+ case Builtin::BI__sync_swap_1:
+ case Builtin::BI__sync_swap_2:
+ case Builtin::BI__sync_swap_4:
+ case Builtin::BI__sync_swap_8:
+ case Builtin::BI__sync_swap_16:
+ return SemaBuiltinAtomicOverloaded(move(TheCallResult));
+#define BUILTIN(ID, TYPE, ATTRS)
+#define ATOMIC_BUILTIN(ID, TYPE, ATTRS) \
+ case Builtin::BI##ID: \
+ return SemaAtomicOpsOverloaded(move(TheCallResult), AtomicExpr::AO##ID);
+#include "clang/Basic/Builtins.def"
+ case Builtin::BI__builtin_annotation:
+ if (CheckBuiltinAnnotationString(*this, TheCall->getArg(1)))
+ return ExprError();
+ break;
+ }
+
+ // Since the target specific builtins for each arch overlap, only check those
+ // of the arch we are compiling for.
+ if (BuiltinID >= Builtin::FirstTSBuiltin) {
+ switch (Context.getTargetInfo().getTriple().getArch()) {
+ case llvm::Triple::arm:
+ case llvm::Triple::thumb:
+ if (CheckARMBuiltinFunctionCall(BuiltinID, TheCall))
+ return ExprError();
+ break;
+ default:
+ break;
+ }
+ }
+
+ return move(TheCallResult);
+}
+
+// Get the valid immediate range for the specified NEON type code.
+static unsigned RFT(unsigned t, bool shift = false) {
+ NeonTypeFlags Type(t);
+ int IsQuad = Type.isQuad();
+ switch (Type.getEltType()) {
+ case NeonTypeFlags::Int8:
+ case NeonTypeFlags::Poly8:
+ return shift ? 7 : (8 << IsQuad) - 1;
+ case NeonTypeFlags::Int16:
+ case NeonTypeFlags::Poly16:
+ return shift ? 15 : (4 << IsQuad) - 1;
+ case NeonTypeFlags::Int32:
+ return shift ? 31 : (2 << IsQuad) - 1;
+ case NeonTypeFlags::Int64:
+ return shift ? 63 : (1 << IsQuad) - 1;
+ case NeonTypeFlags::Float16:
+ assert(!shift && "cannot shift float types!");
+ return (4 << IsQuad) - 1;
+ case NeonTypeFlags::Float32:
+ assert(!shift && "cannot shift float types!");
+ return (2 << IsQuad) - 1;
+ }
+ llvm_unreachable("Invalid NeonTypeFlag!");
+}
+
+/// getNeonEltType - Return the QualType corresponding to the elements of
+/// the vector type specified by the NeonTypeFlags. This is used to check
+/// the pointer arguments for Neon load/store intrinsics.
+static QualType getNeonEltType(NeonTypeFlags Flags, ASTContext &Context) {
+ switch (Flags.getEltType()) {
+ case NeonTypeFlags::Int8:
+ return Flags.isUnsigned() ? Context.UnsignedCharTy : Context.SignedCharTy;
+ case NeonTypeFlags::Int16:
+ return Flags.isUnsigned() ? Context.UnsignedShortTy : Context.ShortTy;
+ case NeonTypeFlags::Int32:
+ return Flags.isUnsigned() ? Context.UnsignedIntTy : Context.IntTy;
+ case NeonTypeFlags::Int64:
+ return Flags.isUnsigned() ? Context.UnsignedLongLongTy : Context.LongLongTy;
+ case NeonTypeFlags::Poly8:
+ return Context.SignedCharTy;
+ case NeonTypeFlags::Poly16:
+ return Context.ShortTy;
+ case NeonTypeFlags::Float16:
+ return Context.UnsignedShortTy;
+ case NeonTypeFlags::Float32:
+ return Context.FloatTy;
+ }
+ llvm_unreachable("Invalid NeonTypeFlag!");
+}
+
+bool Sema::CheckARMBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
+ llvm::APSInt Result;
+
+ unsigned mask = 0;
+ unsigned TV = 0;
+ int PtrArgNum = -1;
+ bool HasConstPtr = false;
+ switch (BuiltinID) {
+#define GET_NEON_OVERLOAD_CHECK
+#include "clang/Basic/arm_neon.inc"
+#undef GET_NEON_OVERLOAD_CHECK
+ }
+
+ // For NEON intrinsics which are overloaded on vector element type, validate
+ // the immediate which specifies which variant to emit.
+ unsigned ImmArg = TheCall->getNumArgs()-1;
+ if (mask) {
+ if (SemaBuiltinConstantArg(TheCall, ImmArg, Result))
+ return true;
+
+ TV = Result.getLimitedValue(64);
+ if ((TV > 63) || (mask & (1 << TV)) == 0)
+ return Diag(TheCall->getLocStart(), diag::err_invalid_neon_type_code)
+ << TheCall->getArg(ImmArg)->getSourceRange();
+ }
+
+ if (PtrArgNum >= 0) {
+ // Check that pointer arguments have the specified type.
+ Expr *Arg = TheCall->getArg(PtrArgNum);
+ if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Arg))
+ Arg = ICE->getSubExpr();
+ ExprResult RHS = DefaultFunctionArrayLvalueConversion(Arg);
+ QualType RHSTy = RHS.get()->getType();
+ QualType EltTy = getNeonEltType(NeonTypeFlags(TV), Context);
+ if (HasConstPtr)
+ EltTy = EltTy.withConst();
+ QualType LHSTy = Context.getPointerType(EltTy);
+ AssignConvertType ConvTy;
+ ConvTy = CheckSingleAssignmentConstraints(LHSTy, RHS);
+ if (RHS.isInvalid())
+ return true;
+ if (DiagnoseAssignmentResult(ConvTy, Arg->getLocStart(), LHSTy, RHSTy,
+ RHS.get(), AA_Assigning))
+ return true;
+ }
+
+ // For NEON intrinsics which take an immediate value as part of the
+ // instruction, range check them here.
+ unsigned i = 0, l = 0, u = 0;
+ switch (BuiltinID) {
+ default: return false;
+ case ARM::BI__builtin_arm_ssat: i = 1; l = 1; u = 31; break;
+ case ARM::BI__builtin_arm_usat: i = 1; u = 31; break;
+ case ARM::BI__builtin_arm_vcvtr_f:
+ case ARM::BI__builtin_arm_vcvtr_d: i = 1; u = 1; break;
+#define GET_NEON_IMMEDIATE_CHECK
+#include "clang/Basic/arm_neon.inc"
+#undef GET_NEON_IMMEDIATE_CHECK
+ };
+
+ // Check that the immediate argument is actually a constant.
+ if (SemaBuiltinConstantArg(TheCall, i, Result))
+ return true;
+
+ // Range check against the upper/lower values for this isntruction.
+ unsigned Val = Result.getZExtValue();
+ if (Val < l || Val > (u + l))
+ return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
+ << l << u+l << TheCall->getArg(i)->getSourceRange();
+
+ // FIXME: VFP Intrinsics should error if VFP not present.
+ return false;
+}
+
+/// CheckFunctionCall - Check a direct function call for various correctness
+/// and safety properties not strictly enforced by the C type system.
+bool Sema::CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCall) {
+ // Get the IdentifierInfo* for the called function.
+ IdentifierInfo *FnInfo = FDecl->getIdentifier();
+
+ // None of the checks below are needed for functions that don't have
+ // simple names (e.g., C++ conversion functions).
+ if (!FnInfo)
+ return false;
+
+ // FIXME: This mechanism should be abstracted to be less fragile and
+ // more efficient. For example, just map function ids to custom
+ // handlers.
+
+ // Printf and scanf checking.
+ for (specific_attr_iterator<FormatAttr>
+ i = FDecl->specific_attr_begin<FormatAttr>(),
+ e = FDecl->specific_attr_end<FormatAttr>(); i != e ; ++i) {
+ CheckFormatArguments(*i, TheCall);
+ }
+
+ for (specific_attr_iterator<NonNullAttr>
+ i = FDecl->specific_attr_begin<NonNullAttr>(),
+ e = FDecl->specific_attr_end<NonNullAttr>(); i != e; ++i) {
+ CheckNonNullArguments(*i, TheCall->getArgs(),
+ TheCall->getCallee()->getLocStart());
+ }
+
+ unsigned CMId = FDecl->getMemoryFunctionKind();
+ if (CMId == 0)
+ return false;
+
+ // Handle memory setting and copying functions.
+ if (CMId == Builtin::BIstrlcpy || CMId == Builtin::BIstrlcat)
+ CheckStrlcpycatArguments(TheCall, FnInfo);
+ else if (CMId == Builtin::BIstrncat)
+ CheckStrncatArguments(TheCall, FnInfo);
+ else
+ CheckMemaccessArguments(TheCall, CMId, FnInfo);
+
+ return false;
+}
+
+bool Sema::CheckObjCMethodCall(ObjCMethodDecl *Method, SourceLocation lbrac,
+ Expr **Args, unsigned NumArgs) {
+ for (specific_attr_iterator<FormatAttr>
+ i = Method->specific_attr_begin<FormatAttr>(),
+ e = Method->specific_attr_end<FormatAttr>(); i != e ; ++i) {
+
+ CheckFormatArguments(*i, Args, NumArgs, false, lbrac,
+ Method->getSourceRange());
+ }
+
+ // diagnose nonnull arguments.
+ for (specific_attr_iterator<NonNullAttr>
+ i = Method->specific_attr_begin<NonNullAttr>(),
+ e = Method->specific_attr_end<NonNullAttr>(); i != e; ++i) {
+ CheckNonNullArguments(*i, Args, lbrac);
+ }
+
+ return false;
+}
+
+bool Sema::CheckBlockCall(NamedDecl *NDecl, CallExpr *TheCall) {
+ const VarDecl *V = dyn_cast<VarDecl>(NDecl);
+ if (!V)
+ return false;
+
+ QualType Ty = V->getType();
+ if (!Ty->isBlockPointerType())
+ return false;
+
+ // format string checking.
+ for (specific_attr_iterator<FormatAttr>
+ i = NDecl->specific_attr_begin<FormatAttr>(),
+ e = NDecl->specific_attr_end<FormatAttr>(); i != e ; ++i) {
+ CheckFormatArguments(*i, TheCall);
+ }
+
+ return false;
+}
+
+ExprResult Sema::SemaAtomicOpsOverloaded(ExprResult TheCallResult,
+ AtomicExpr::AtomicOp Op) {
+ CallExpr *TheCall = cast<CallExpr>(TheCallResult.get());
+ DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
+
+ // All these operations take one of the following forms:
+ enum {
+ // C __c11_atomic_init(A *, C)
+ Init,
+ // C __c11_atomic_load(A *, int)
+ Load,
+ // void __atomic_load(A *, CP, int)
+ Copy,
+ // C __c11_atomic_add(A *, M, int)
+ Arithmetic,
+ // C __atomic_exchange_n(A *, CP, int)
+ Xchg,
+ // void __atomic_exchange(A *, C *, CP, int)
+ GNUXchg,
+ // bool __c11_atomic_compare_exchange_strong(A *, C *, CP, int, int)
+ C11CmpXchg,
+ // bool __atomic_compare_exchange(A *, C *, CP, bool, int, int)
+ GNUCmpXchg
+ } Form = Init;
+ const unsigned NumArgs[] = { 2, 2, 3, 3, 3, 4, 5, 6 };
+ const unsigned NumVals[] = { 1, 0, 1, 1, 1, 2, 2, 3 };
+ // where:
+ // C is an appropriate type,
+ // A is volatile _Atomic(C) for __c11 builtins and is C for GNU builtins,
+ // CP is C for __c11 builtins and GNU _n builtins and is C * otherwise,
+ // M is C if C is an integer, and ptrdiff_t if C is a pointer, and
+ // the int parameters are for orderings.
+
+ assert(AtomicExpr::AO__c11_atomic_init == 0 &&
+ AtomicExpr::AO__c11_atomic_fetch_xor + 1 == AtomicExpr::AO__atomic_load
+ && "need to update code for modified C11 atomics");
+ bool IsC11 = Op >= AtomicExpr::AO__c11_atomic_init &&
+ Op <= AtomicExpr::AO__c11_atomic_fetch_xor;
+ bool IsN = Op == AtomicExpr::AO__atomic_load_n ||
+ Op == AtomicExpr::AO__atomic_store_n ||
+ Op == AtomicExpr::AO__atomic_exchange_n ||
+ Op == AtomicExpr::AO__atomic_compare_exchange_n;
+ bool IsAddSub = false;
+
+ switch (Op) {
+ case AtomicExpr::AO__c11_atomic_init:
+ Form = Init;
+ break;
+
+ case AtomicExpr::AO__c11_atomic_load:
+ case AtomicExpr::AO__atomic_load_n:
+ Form = Load;
+ break;
+
+ case AtomicExpr::AO__c11_atomic_store:
+ case AtomicExpr::AO__atomic_load:
+ case AtomicExpr::AO__atomic_store:
+ case AtomicExpr::AO__atomic_store_n:
+ Form = Copy;
+ break;
+
+ case AtomicExpr::AO__c11_atomic_fetch_add:
+ case AtomicExpr::AO__c11_atomic_fetch_sub:
+ case AtomicExpr::AO__atomic_fetch_add:
+ case AtomicExpr::AO__atomic_fetch_sub:
+ case AtomicExpr::AO__atomic_add_fetch:
+ case AtomicExpr::AO__atomic_sub_fetch:
+ IsAddSub = true;
+ // Fall through.
+ case AtomicExpr::AO__c11_atomic_fetch_and:
+ case AtomicExpr::AO__c11_atomic_fetch_or:
+ case AtomicExpr::AO__c11_atomic_fetch_xor:
+ case AtomicExpr::AO__atomic_fetch_and:
+ case AtomicExpr::AO__atomic_fetch_or:
+ case AtomicExpr::AO__atomic_fetch_xor:
+ case AtomicExpr::AO__atomic_fetch_nand:
+ case AtomicExpr::AO__atomic_and_fetch:
+ case AtomicExpr::AO__atomic_or_fetch:
+ case AtomicExpr::AO__atomic_xor_fetch:
+ case AtomicExpr::AO__atomic_nand_fetch:
+ Form = Arithmetic;
+ break;
+
+ case AtomicExpr::AO__c11_atomic_exchange:
+ case AtomicExpr::AO__atomic_exchange_n:
+ Form = Xchg;
+ break;
+
+ case AtomicExpr::AO__atomic_exchange:
+ Form = GNUXchg;
+ break;
+
+ case AtomicExpr::AO__c11_atomic_compare_exchange_strong:
+ case AtomicExpr::AO__c11_atomic_compare_exchange_weak:
+ Form = C11CmpXchg;
+ break;
+
+ case AtomicExpr::AO__atomic_compare_exchange:
+ case AtomicExpr::AO__atomic_compare_exchange_n:
+ Form = GNUCmpXchg;
+ break;
+ }
+
+ // Check we have the right number of arguments.
+ if (TheCall->getNumArgs() < NumArgs[Form]) {
+ Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
+ << 0 << NumArgs[Form] << TheCall->getNumArgs()
+ << TheCall->getCallee()->getSourceRange();
+ return ExprError();
+ } else if (TheCall->getNumArgs() > NumArgs[Form]) {
+ Diag(TheCall->getArg(NumArgs[Form])->getLocStart(),
+ diag::err_typecheck_call_too_many_args)
+ << 0 << NumArgs[Form] << TheCall->getNumArgs()
+ << TheCall->getCallee()->getSourceRange();
+ return ExprError();
+ }
+
+ // Inspect the first argument of the atomic operation.
+ Expr *Ptr = TheCall->getArg(0);
+ Ptr = DefaultFunctionArrayLvalueConversion(Ptr).get();
+ const PointerType *pointerType = Ptr->getType()->getAs<PointerType>();
+ if (!pointerType) {
+ Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer)
+ << Ptr->getType() << Ptr->getSourceRange();
+ return ExprError();
+ }
+
+ // For a __c11 builtin, this should be a pointer to an _Atomic type.
+ QualType AtomTy = pointerType->getPointeeType(); // 'A'
+ QualType ValType = AtomTy; // 'C'
+ if (IsC11) {
+ if (!AtomTy->isAtomicType()) {
+ Diag(DRE->getLocStart(), diag::err_atomic_op_needs_atomic)
+ << Ptr->getType() << Ptr->getSourceRange();
+ return ExprError();
+ }
+ ValType = AtomTy->getAs<AtomicType>()->getValueType();
+ }
+
+ // For an arithmetic operation, the implied arithmetic must be well-formed.
+ if (Form == Arithmetic) {
+ // gcc does not enforce these rules for GNU atomics, but we do so for sanity.
+ if (IsAddSub && !ValType->isIntegerType() && !ValType->isPointerType()) {
+ Diag(DRE->getLocStart(), diag::err_atomic_op_needs_atomic_int_or_ptr)
+ << IsC11 << Ptr->getType() << Ptr->getSourceRange();
+ return ExprError();
+ }
+ if (!IsAddSub && !ValType->isIntegerType()) {
+ Diag(DRE->getLocStart(), diag::err_atomic_op_bitwise_needs_atomic_int)
+ << IsC11 << Ptr->getType() << Ptr->getSourceRange();
+ return ExprError();
+ }
+ } else if (IsN && !ValType->isIntegerType() && !ValType->isPointerType()) {
+ // For __atomic_*_n operations, the value type must be a scalar integral or
+ // pointer type which is 1, 2, 4, 8 or 16 bytes in length.
+ Diag(DRE->getLocStart(), diag::err_atomic_op_needs_atomic_int_or_ptr)
+ << IsC11 << Ptr->getType() << Ptr->getSourceRange();
+ return ExprError();
+ }
+
+ if (!IsC11 && !AtomTy.isTriviallyCopyableType(Context)) {
+ // For GNU atomics, require a trivially-copyable type. This is not part of
+ // the GNU atomics specification, but we enforce it for sanity.
+ Diag(DRE->getLocStart(), diag::err_atomic_op_needs_trivial_copy)
+ << Ptr->getType() << Ptr->getSourceRange();
+ return ExprError();
+ }
+
+ // FIXME: For any builtin other than a load, the ValType must not be
+ // const-qualified.
+
+ switch (ValType.getObjCLifetime()) {
+ case Qualifiers::OCL_None:
+ case Qualifiers::OCL_ExplicitNone:
+ // okay
+ break;
+
+ case Qualifiers::OCL_Weak:
+ case Qualifiers::OCL_Strong:
+ case Qualifiers::OCL_Autoreleasing:
+ // FIXME: Can this happen? By this point, ValType should be known
+ // to be trivially copyable.
+ Diag(DRE->getLocStart(), diag::err_arc_atomic_ownership)
+ << ValType << Ptr->getSourceRange();
+ return ExprError();
+ }
+
+ QualType ResultType = ValType;
+ if (Form == Copy || Form == GNUXchg || Form == Init)
+ ResultType = Context.VoidTy;
+ else if (Form == C11CmpXchg || Form == GNUCmpXchg)
+ ResultType = Context.BoolTy;
+
+ // The type of a parameter passed 'by value'. In the GNU atomics, such
+ // arguments are actually passed as pointers.
+ QualType ByValType = ValType; // 'CP'
+ if (!IsC11 && !IsN)
+ ByValType = Ptr->getType();
+
+ // The first argument --- the pointer --- has a fixed type; we
+ // deduce the types of the rest of the arguments accordingly. Walk
+ // the remaining arguments, converting them to the deduced value type.
+ for (unsigned i = 1; i != NumArgs[Form]; ++i) {
+ QualType Ty;
+ if (i < NumVals[Form] + 1) {
+ switch (i) {
+ case 1:
+ // The second argument is the non-atomic operand. For arithmetic, this
+ // is always passed by value, and for a compare_exchange it is always
+ // passed by address. For the rest, GNU uses by-address and C11 uses
+ // by-value.
+ assert(Form != Load);
+ if (Form == Init || (Form == Arithmetic && ValType->isIntegerType()))
+ Ty = ValType;
+ else if (Form == Copy || Form == Xchg)
+ Ty = ByValType;
+ else if (Form == Arithmetic)
+ Ty = Context.getPointerDiffType();
+ else
+ Ty = Context.getPointerType(ValType.getUnqualifiedType());
+ break;
+ case 2:
+ // The third argument to compare_exchange / GNU exchange is a
+ // (pointer to a) desired value.
+ Ty = ByValType;
+ break;
+ case 3:
+ // The fourth argument to GNU compare_exchange is a 'weak' flag.
+ Ty = Context.BoolTy;
+ break;
+ }
+ } else {
+ // The order(s) are always converted to int.
+ Ty = Context.IntTy;
+ }
+
+ InitializedEntity Entity =
+ InitializedEntity::InitializeParameter(Context, Ty, false);
+ ExprResult Arg = TheCall->getArg(i);
+ Arg = PerformCopyInitialization(Entity, SourceLocation(), Arg);
+ if (Arg.isInvalid())
+ return true;
+ TheCall->setArg(i, Arg.get());
+ }
+
+ // Permute the arguments into a 'consistent' order.
+ SmallVector<Expr*, 5> SubExprs;
+ SubExprs.push_back(Ptr);
+ switch (Form) {
+ case Init:
+ // Note, AtomicExpr::getVal1() has a special case for this atomic.
+ SubExprs.push_back(TheCall->getArg(1)); // Val1
+ break;
+ case Load:
+ SubExprs.push_back(TheCall->getArg(1)); // Order
+ break;
+ case Copy:
+ case Arithmetic:
+ case Xchg:
+ SubExprs.push_back(TheCall->getArg(2)); // Order
+ SubExprs.push_back(TheCall->getArg(1)); // Val1
+ break;
+ case GNUXchg:
+ // Note, AtomicExpr::getVal2() has a special case for this atomic.
+ SubExprs.push_back(TheCall->getArg(3)); // Order
+ SubExprs.push_back(TheCall->getArg(1)); // Val1
+ SubExprs.push_back(TheCall->getArg(2)); // Val2
+ break;
+ case C11CmpXchg:
+ SubExprs.push_back(TheCall->getArg(3)); // Order
+ SubExprs.push_back(TheCall->getArg(1)); // Val1
+ SubExprs.push_back(TheCall->getArg(4)); // OrderFail
+ SubExprs.push_back(TheCall->getArg(2)); // Val2
+ break;
+ case GNUCmpXchg:
+ SubExprs.push_back(TheCall->getArg(4)); // Order
+ SubExprs.push_back(TheCall->getArg(1)); // Val1
+ SubExprs.push_back(TheCall->getArg(5)); // OrderFail
+ SubExprs.push_back(TheCall->getArg(2)); // Val2
+ SubExprs.push_back(TheCall->getArg(3)); // Weak
+ break;
+ }
+
+ return Owned(new (Context) AtomicExpr(TheCall->getCallee()->getLocStart(),
+ SubExprs.data(), SubExprs.size(),
+ ResultType, Op,
+ TheCall->getRParenLoc()));
+}
+
+
+/// checkBuiltinArgument - Given a call to a builtin function, perform
+/// normal type-checking on the given argument, updating the call in
+/// place. This is useful when a builtin function requires custom
+/// type-checking for some of its arguments but not necessarily all of
+/// them.
+///
+/// Returns true on error.
+static bool checkBuiltinArgument(Sema &S, CallExpr *E, unsigned ArgIndex) {
+ FunctionDecl *Fn = E->getDirectCallee();
+ assert(Fn && "builtin call without direct callee!");
+
+ ParmVarDecl *Param = Fn->getParamDecl(ArgIndex);
+ InitializedEntity Entity =
+ InitializedEntity::InitializeParameter(S.Context, Param);
+
+ ExprResult Arg = E->getArg(0);
+ Arg = S.PerformCopyInitialization(Entity, SourceLocation(), Arg);
+ if (Arg.isInvalid())
+ return true;
+
+ E->setArg(ArgIndex, Arg.take());
+ return false;
+}
+
+/// SemaBuiltinAtomicOverloaded - We have a call to a function like
+/// __sync_fetch_and_add, which is an overloaded function based on the pointer
+/// type of its first argument. The main ActOnCallExpr routines have already
+/// promoted the types of arguments because all of these calls are prototyped as
+/// void(...).
+///
+/// This function goes through and does final semantic checking for these
+/// builtins,
+ExprResult
+Sema::SemaBuiltinAtomicOverloaded(ExprResult TheCallResult) {
+ CallExpr *TheCall = (CallExpr *)TheCallResult.get();
+ DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
+ FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl());
+
+ // Ensure that we have at least one argument to do type inference from.
+ if (TheCall->getNumArgs() < 1) {
+ Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args_at_least)
+ << 0 << 1 << TheCall->getNumArgs()
+ << TheCall->getCallee()->getSourceRange();
+ return ExprError();
+ }
+
+ // Inspect the first argument of the atomic builtin. This should always be
+ // a pointer type, whose element is an integral scalar or pointer type.
+ // Because it is a pointer type, we don't have to worry about any implicit
+ // casts here.
+ // FIXME: We don't allow floating point scalars as input.
+ Expr *FirstArg = TheCall->getArg(0);
+ ExprResult FirstArgResult = DefaultFunctionArrayLvalueConversion(FirstArg);
+ if (FirstArgResult.isInvalid())
+ return ExprError();
+ FirstArg = FirstArgResult.take();
+ TheCall->setArg(0, FirstArg);
+
+ const PointerType *pointerType = FirstArg->getType()->getAs<PointerType>();
+ if (!pointerType) {
+ Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer)
+ << FirstArg->getType() << FirstArg->getSourceRange();
+ return ExprError();
+ }
+
+ QualType ValType = pointerType->getPointeeType();
+ if (!ValType->isIntegerType() && !ValType->isAnyPointerType() &&
+ !ValType->isBlockPointerType()) {
+ Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer_intptr)
+ << FirstArg->getType() << FirstArg->getSourceRange();
+ return ExprError();
+ }
+
+ switch (ValType.getObjCLifetime()) {
+ case Qualifiers::OCL_None:
+ case Qualifiers::OCL_ExplicitNone:
+ // okay
+ break;
+
+ case Qualifiers::OCL_Weak:
+ case Qualifiers::OCL_Strong:
+ case Qualifiers::OCL_Autoreleasing:
+ Diag(DRE->getLocStart(), diag::err_arc_atomic_ownership)
+ << ValType << FirstArg->getSourceRange();
+ return ExprError();
+ }
+
+ // Strip any qualifiers off ValType.
+ ValType = ValType.getUnqualifiedType();
+
+ // The majority of builtins return a value, but a few have special return
+ // types, so allow them to override appropriately below.
+ QualType ResultType = ValType;
+
+ // We need to figure out which concrete builtin this maps onto. For example,
+ // __sync_fetch_and_add with a 2 byte object turns into
+ // __sync_fetch_and_add_2.
+#define BUILTIN_ROW(x) \
+ { Builtin::BI##x##_1, Builtin::BI##x##_2, Builtin::BI##x##_4, \
+ Builtin::BI##x##_8, Builtin::BI##x##_16 }
+
+ static const unsigned BuiltinIndices[][5] = {
+ BUILTIN_ROW(__sync_fetch_and_add),
+ BUILTIN_ROW(__sync_fetch_and_sub),
+ BUILTIN_ROW(__sync_fetch_and_or),
+ BUILTIN_ROW(__sync_fetch_and_and),
+ BUILTIN_ROW(__sync_fetch_and_xor),
+
+ BUILTIN_ROW(__sync_add_and_fetch),
+ BUILTIN_ROW(__sync_sub_and_fetch),
+ BUILTIN_ROW(__sync_and_and_fetch),
+ BUILTIN_ROW(__sync_or_and_fetch),
+ BUILTIN_ROW(__sync_xor_and_fetch),
+
+ BUILTIN_ROW(__sync_val_compare_and_swap),
+ BUILTIN_ROW(__sync_bool_compare_and_swap),
+ BUILTIN_ROW(__sync_lock_test_and_set),
+ BUILTIN_ROW(__sync_lock_release),
+ BUILTIN_ROW(__sync_swap)
+ };
+#undef BUILTIN_ROW
+
+ // Determine the index of the size.
+ unsigned SizeIndex;
+ switch (Context.getTypeSizeInChars(ValType).getQuantity()) {
+ case 1: SizeIndex = 0; break;
+ case 2: SizeIndex = 1; break;
+ case 4: SizeIndex = 2; break;
+ case 8: SizeIndex = 3; break;
+ case 16: SizeIndex = 4; break;
+ default:
+ Diag(DRE->getLocStart(), diag::err_atomic_builtin_pointer_size)
+ << FirstArg->getType() << FirstArg->getSourceRange();
+ return ExprError();
+ }
+
+ // Each of these builtins has one pointer argument, followed by some number of
+ // values (0, 1 or 2) followed by a potentially empty varags list of stuff
+ // that we ignore. Find out which row of BuiltinIndices to read from as well
+ // as the number of fixed args.
+ unsigned BuiltinID = FDecl->getBuiltinID();
+ unsigned BuiltinIndex, NumFixed = 1;
+ switch (BuiltinID) {
+ default: llvm_unreachable("Unknown overloaded atomic builtin!");
+ case Builtin::BI__sync_fetch_and_add:
+ case Builtin::BI__sync_fetch_and_add_1:
+ case Builtin::BI__sync_fetch_and_add_2:
+ case Builtin::BI__sync_fetch_and_add_4:
+ case Builtin::BI__sync_fetch_and_add_8:
+ case Builtin::BI__sync_fetch_and_add_16:
+ BuiltinIndex = 0;
+ break;
+
+ case Builtin::BI__sync_fetch_and_sub:
+ case Builtin::BI__sync_fetch_and_sub_1:
+ case Builtin::BI__sync_fetch_and_sub_2:
+ case Builtin::BI__sync_fetch_and_sub_4:
+ case Builtin::BI__sync_fetch_and_sub_8:
+ case Builtin::BI__sync_fetch_and_sub_16:
+ BuiltinIndex = 1;
+ break;
+
+ case Builtin::BI__sync_fetch_and_or:
+ case Builtin::BI__sync_fetch_and_or_1:
+ case Builtin::BI__sync_fetch_and_or_2:
+ case Builtin::BI__sync_fetch_and_or_4:
+ case Builtin::BI__sync_fetch_and_or_8:
+ case Builtin::BI__sync_fetch_and_or_16:
+ BuiltinIndex = 2;
+ break;
+
+ case Builtin::BI__sync_fetch_and_and:
+ case Builtin::BI__sync_fetch_and_and_1:
+ case Builtin::BI__sync_fetch_and_and_2:
+ case Builtin::BI__sync_fetch_and_and_4:
+ case Builtin::BI__sync_fetch_and_and_8:
+ case Builtin::BI__sync_fetch_and_and_16:
+ BuiltinIndex = 3;
+ break;
+
+ case Builtin::BI__sync_fetch_and_xor:
+ case Builtin::BI__sync_fetch_and_xor_1:
+ case Builtin::BI__sync_fetch_and_xor_2:
+ case Builtin::BI__sync_fetch_and_xor_4:
+ case Builtin::BI__sync_fetch_and_xor_8:
+ case Builtin::BI__sync_fetch_and_xor_16:
+ BuiltinIndex = 4;
+ break;
+
+ case Builtin::BI__sync_add_and_fetch:
+ case Builtin::BI__sync_add_and_fetch_1:
+ case Builtin::BI__sync_add_and_fetch_2:
+ case Builtin::BI__sync_add_and_fetch_4:
+ case Builtin::BI__sync_add_and_fetch_8:
+ case Builtin::BI__sync_add_and_fetch_16:
+ BuiltinIndex = 5;
+ break;
+
+ case Builtin::BI__sync_sub_and_fetch:
+ case Builtin::BI__sync_sub_and_fetch_1:
+ case Builtin::BI__sync_sub_and_fetch_2:
+ case Builtin::BI__sync_sub_and_fetch_4:
+ case Builtin::BI__sync_sub_and_fetch_8:
+ case Builtin::BI__sync_sub_and_fetch_16:
+ BuiltinIndex = 6;
+ break;
+
+ case Builtin::BI__sync_and_and_fetch:
+ case Builtin::BI__sync_and_and_fetch_1:
+ case Builtin::BI__sync_and_and_fetch_2:
+ case Builtin::BI__sync_and_and_fetch_4:
+ case Builtin::BI__sync_and_and_fetch_8:
+ case Builtin::BI__sync_and_and_fetch_16:
+ BuiltinIndex = 7;
+ break;
+
+ case Builtin::BI__sync_or_and_fetch:
+ case Builtin::BI__sync_or_and_fetch_1:
+ case Builtin::BI__sync_or_and_fetch_2:
+ case Builtin::BI__sync_or_and_fetch_4:
+ case Builtin::BI__sync_or_and_fetch_8:
+ case Builtin::BI__sync_or_and_fetch_16:
+ BuiltinIndex = 8;
+ break;
+
+ case Builtin::BI__sync_xor_and_fetch:
+ case Builtin::BI__sync_xor_and_fetch_1:
+ case Builtin::BI__sync_xor_and_fetch_2:
+ case Builtin::BI__sync_xor_and_fetch_4:
+ case Builtin::BI__sync_xor_and_fetch_8:
+ case Builtin::BI__sync_xor_and_fetch_16:
+ BuiltinIndex = 9;
+ break;
+
+ case Builtin::BI__sync_val_compare_and_swap:
+ case Builtin::BI__sync_val_compare_and_swap_1:
+ case Builtin::BI__sync_val_compare_and_swap_2:
+ case Builtin::BI__sync_val_compare_and_swap_4:
+ case Builtin::BI__sync_val_compare_and_swap_8:
+ case Builtin::BI__sync_val_compare_and_swap_16:
+ BuiltinIndex = 10;
+ NumFixed = 2;
+ break;
+
+ case Builtin::BI__sync_bool_compare_and_swap:
+ case Builtin::BI__sync_bool_compare_and_swap_1:
+ case Builtin::BI__sync_bool_compare_and_swap_2:
+ case Builtin::BI__sync_bool_compare_and_swap_4:
+ case Builtin::BI__sync_bool_compare_and_swap_8:
+ case Builtin::BI__sync_bool_compare_and_swap_16:
+ BuiltinIndex = 11;
+ NumFixed = 2;
+ ResultType = Context.BoolTy;
+ break;
+
+ case Builtin::BI__sync_lock_test_and_set:
+ case Builtin::BI__sync_lock_test_and_set_1:
+ case Builtin::BI__sync_lock_test_and_set_2:
+ case Builtin::BI__sync_lock_test_and_set_4:
+ case Builtin::BI__sync_lock_test_and_set_8:
+ case Builtin::BI__sync_lock_test_and_set_16:
+ BuiltinIndex = 12;
+ break;
+
+ case Builtin::BI__sync_lock_release:
+ case Builtin::BI__sync_lock_release_1:
+ case Builtin::BI__sync_lock_release_2:
+ case Builtin::BI__sync_lock_release_4:
+ case Builtin::BI__sync_lock_release_8:
+ case Builtin::BI__sync_lock_release_16:
+ BuiltinIndex = 13;
+ NumFixed = 0;
+ ResultType = Context.VoidTy;
+ break;
+
+ case Builtin::BI__sync_swap:
+ case Builtin::BI__sync_swap_1:
+ case Builtin::BI__sync_swap_2:
+ case Builtin::BI__sync_swap_4:
+ case Builtin::BI__sync_swap_8:
+ case Builtin::BI__sync_swap_16:
+ BuiltinIndex = 14;
+ break;
+ }
+
+ // Now that we know how many fixed arguments we expect, first check that we
+ // have at least that many.
+ if (TheCall->getNumArgs() < 1+NumFixed) {
+ Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args_at_least)
+ << 0 << 1+NumFixed << TheCall->getNumArgs()
+ << TheCall->getCallee()->getSourceRange();
+ return ExprError();
+ }
+
+ // Get the decl for the concrete builtin from this, we can tell what the
+ // concrete integer type we should convert to is.
+ unsigned NewBuiltinID = BuiltinIndices[BuiltinIndex][SizeIndex];
+ const char *NewBuiltinName = Context.BuiltinInfo.GetName(NewBuiltinID);
+ IdentifierInfo *NewBuiltinII = PP.getIdentifierInfo(NewBuiltinName);
+ FunctionDecl *NewBuiltinDecl =
+ cast<FunctionDecl>(LazilyCreateBuiltin(NewBuiltinII, NewBuiltinID,
+ TUScope, false, DRE->getLocStart()));
+
+ // The first argument --- the pointer --- has a fixed type; we
+ // deduce the types of the rest of the arguments accordingly. Walk
+ // the remaining arguments, converting them to the deduced value type.
+ for (unsigned i = 0; i != NumFixed; ++i) {
+ ExprResult Arg = TheCall->getArg(i+1);
+
+ // GCC does an implicit conversion to the pointer or integer ValType. This
+ // can fail in some cases (1i -> int**), check for this error case now.
+ // Initialize the argument.
+ InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
+ ValType, /*consume*/ false);
+ Arg = PerformCopyInitialization(Entity, SourceLocation(), Arg);
+ if (Arg.isInvalid())
+ return ExprError();
+
+ // Okay, we have something that *can* be converted to the right type. Check
+ // to see if there is a potentially weird extension going on here. This can
+ // happen when you do an atomic operation on something like an char* and
+ // pass in 42. The 42 gets converted to char. This is even more strange
+ // for things like 45.123 -> char, etc.
+ // FIXME: Do this check.
+ TheCall->setArg(i+1, Arg.take());
+ }
+
+ ASTContext& Context = this->getASTContext();
+
+ // Create a new DeclRefExpr to refer to the new decl.
+ DeclRefExpr* NewDRE = DeclRefExpr::Create(
+ Context,
+ DRE->getQualifierLoc(),
+ SourceLocation(),
+ NewBuiltinDecl,
+ /*enclosing*/ false,
+ DRE->getLocation(),
+ NewBuiltinDecl->getType(),
+ DRE->getValueKind());
+
+ // Set the callee in the CallExpr.
+ // FIXME: This leaks the original parens and implicit casts.
+ ExprResult PromotedCall = UsualUnaryConversions(NewDRE);
+ if (PromotedCall.isInvalid())
+ return ExprError();
+ TheCall->setCallee(PromotedCall.take());
+
+ // Change the result type of the call to match the original value type. This
+ // is arbitrary, but the codegen for these builtins ins design to handle it
+ // gracefully.
+ TheCall->setType(ResultType);
+
+ return move(TheCallResult);
+}
+
+/// CheckObjCString - Checks that the argument to the builtin
+/// CFString constructor is correct
+/// Note: It might also make sense to do the UTF-16 conversion here (would
+/// simplify the backend).
+bool Sema::CheckObjCString(Expr *Arg) {
+ Arg = Arg->IgnoreParenCasts();
+ StringLiteral *Literal = dyn_cast<StringLiteral>(Arg);
+
+ if (!Literal || !Literal->isAscii()) {
+ Diag(Arg->getLocStart(), diag::err_cfstring_literal_not_string_constant)
+ << Arg->getSourceRange();
+ return true;
+ }
+
+ if (Literal->containsNonAsciiOrNull()) {
+ StringRef String = Literal->getString();
+ unsigned NumBytes = String.size();
+ SmallVector<UTF16, 128> ToBuf(NumBytes);
+ const UTF8 *FromPtr = (UTF8 *)String.data();
+ UTF16 *ToPtr = &ToBuf[0];
+
+ ConversionResult Result = ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes,
+ &ToPtr, ToPtr + NumBytes,
+ strictConversion);
+ // Check for conversion failure.
+ if (Result != conversionOK)
+ Diag(Arg->getLocStart(),
+ diag::warn_cfstring_truncated) << Arg->getSourceRange();
+ }
+ return false;
+}
+
+/// SemaBuiltinVAStart - Check the arguments to __builtin_va_start for validity.
+/// Emit an error and return true on failure, return false on success.
+bool Sema::SemaBuiltinVAStart(CallExpr *TheCall) {
+ Expr *Fn = TheCall->getCallee();
+ if (TheCall->getNumArgs() > 2) {
+ Diag(TheCall->getArg(2)->getLocStart(),
+ diag::err_typecheck_call_too_many_args)
+ << 0 /*function call*/ << 2 << TheCall->getNumArgs()
+ << Fn->getSourceRange()
+ << SourceRange(TheCall->getArg(2)->getLocStart(),
+ (*(TheCall->arg_end()-1))->getLocEnd());
+ return true;
+ }
+
+ if (TheCall->getNumArgs() < 2) {
+ return Diag(TheCall->getLocEnd(),
+ diag::err_typecheck_call_too_few_args_at_least)
+ << 0 /*function call*/ << 2 << TheCall->getNumArgs();
+ }
+
+ // Type-check the first argument normally.
+ if (checkBuiltinArgument(*this, TheCall, 0))
+ return true;
+
+ // Determine whether the current function is variadic or not.
+ BlockScopeInfo *CurBlock = getCurBlock();
+ bool isVariadic;
+ if (CurBlock)
+ isVariadic = CurBlock->TheDecl->isVariadic();
+ else if (FunctionDecl *FD = getCurFunctionDecl())
+ isVariadic = FD->isVariadic();
+ else
+ isVariadic = getCurMethodDecl()->isVariadic();
+
+ if (!isVariadic) {
+ Diag(Fn->getLocStart(), diag::err_va_start_used_in_non_variadic_function);
+ return true;
+ }
+
+ // Verify that the second argument to the builtin is the last argument of the
+ // current function or method.
+ bool SecondArgIsLastNamedArgument = false;
+ const Expr *Arg = TheCall->getArg(1)->IgnoreParenCasts();
+
+ if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Arg)) {
+ if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(DR->getDecl())) {
+ // FIXME: This isn't correct for methods (results in bogus warning).
+ // Get the last formal in the current function.
+ const ParmVarDecl *LastArg;
+ if (CurBlock)
+ LastArg = *(CurBlock->TheDecl->param_end()-1);
+ else if (FunctionDecl *FD = getCurFunctionDecl())
+ LastArg = *(FD->param_end()-1);
+ else
+ LastArg = *(getCurMethodDecl()->param_end()-1);
+ SecondArgIsLastNamedArgument = PV == LastArg;
+ }
+ }
+
+ if (!SecondArgIsLastNamedArgument)
+ Diag(TheCall->getArg(1)->getLocStart(),
+ diag::warn_second_parameter_of_va_start_not_last_named_argument);
+ return false;
+}
+
+/// SemaBuiltinUnorderedCompare - Handle functions like __builtin_isgreater and
+/// friends. This is declared to take (...), so we have to check everything.
+bool Sema::SemaBuiltinUnorderedCompare(CallExpr *TheCall) {
+ if (TheCall->getNumArgs() < 2)
+ return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
+ << 0 << 2 << TheCall->getNumArgs()/*function call*/;
+ if (TheCall->getNumArgs() > 2)
+ return Diag(TheCall->getArg(2)->getLocStart(),
+ diag::err_typecheck_call_too_many_args)
+ << 0 /*function call*/ << 2 << TheCall->getNumArgs()
+ << SourceRange(TheCall->getArg(2)->getLocStart(),
+ (*(TheCall->arg_end()-1))->getLocEnd());
+
+ ExprResult OrigArg0 = TheCall->getArg(0);
+ ExprResult OrigArg1 = TheCall->getArg(1);
+
+ // Do standard promotions between the two arguments, returning their common
+ // type.
+ QualType Res = UsualArithmeticConversions(OrigArg0, OrigArg1, false);
+ if (OrigArg0.isInvalid() || OrigArg1.isInvalid())
+ return true;
+
+ // Make sure any conversions are pushed back into the call; this is
+ // type safe since unordered compare builtins are declared as "_Bool
+ // foo(...)".
+ TheCall->setArg(0, OrigArg0.get());
+ TheCall->setArg(1, OrigArg1.get());
+
+ if (OrigArg0.get()->isTypeDependent() || OrigArg1.get()->isTypeDependent())
+ return false;
+
+ // If the common type isn't a real floating type, then the arguments were
+ // invalid for this operation.
+ if (!Res->isRealFloatingType())
+ return Diag(OrigArg0.get()->getLocStart(),
+ diag::err_typecheck_call_invalid_ordered_compare)
+ << OrigArg0.get()->getType() << OrigArg1.get()->getType()
+ << SourceRange(OrigArg0.get()->getLocStart(), OrigArg1.get()->getLocEnd());
+
+ return false;
+}
+
+/// SemaBuiltinSemaBuiltinFPClassification - Handle functions like
+/// __builtin_isnan and friends. This is declared to take (...), so we have
+/// to check everything. We expect the last argument to be a floating point
+/// value.
+bool Sema::SemaBuiltinFPClassification(CallExpr *TheCall, unsigned NumArgs) {
+ if (TheCall->getNumArgs() < NumArgs)
+ return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
+ << 0 << NumArgs << TheCall->getNumArgs()/*function call*/;
+ if (TheCall->getNumArgs() > NumArgs)
+ return Diag(TheCall->getArg(NumArgs)->getLocStart(),
+ diag::err_typecheck_call_too_many_args)
+ << 0 /*function call*/ << NumArgs << TheCall->getNumArgs()
+ << SourceRange(TheCall->getArg(NumArgs)->getLocStart(),
+ (*(TheCall->arg_end()-1))->getLocEnd());
+
+ Expr *OrigArg = TheCall->getArg(NumArgs-1);
+
+ if (OrigArg->isTypeDependent())
+ return false;
+
+ // This operation requires a non-_Complex floating-point number.
+ if (!OrigArg->getType()->isRealFloatingType())
+ return Diag(OrigArg->getLocStart(),
+ diag::err_typecheck_call_invalid_unary_fp)
+ << OrigArg->getType() << OrigArg->getSourceRange();
+
+ // If this is an implicit conversion from float -> double, remove it.
+ if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(OrigArg)) {
+ Expr *CastArg = Cast->getSubExpr();
+ if (CastArg->getType()->isSpecificBuiltinType(BuiltinType::Float)) {
+ assert(Cast->getType()->isSpecificBuiltinType(BuiltinType::Double) &&
+ "promotion from float to double is the only expected cast here");
+ Cast->setSubExpr(0);
+ TheCall->setArg(NumArgs-1, CastArg);
+ }
+ }
+
+ return false;
+}
+
+/// SemaBuiltinShuffleVector - Handle __builtin_shufflevector.
+// This is declared to take (...), so we have to check everything.
+ExprResult Sema::SemaBuiltinShuffleVector(CallExpr *TheCall) {
+ if (TheCall->getNumArgs() < 2)
+ return ExprError(Diag(TheCall->getLocEnd(),
+ diag::err_typecheck_call_too_few_args_at_least)
+ << 0 /*function call*/ << 2 << TheCall->getNumArgs()
+ << TheCall->getSourceRange());
+
+ // Determine which of the following types of shufflevector we're checking:
+ // 1) unary, vector mask: (lhs, mask)
+ // 2) binary, vector mask: (lhs, rhs, mask)
+ // 3) binary, scalar mask: (lhs, rhs, index, ..., index)
+ QualType resType = TheCall->getArg(0)->getType();
+ unsigned numElements = 0;
+
+ if (!TheCall->getArg(0)->isTypeDependent() &&
+ !TheCall->getArg(1)->isTypeDependent()) {
+ QualType LHSType = TheCall->getArg(0)->getType();
+ QualType RHSType = TheCall->getArg(1)->getType();
+
+ if (!LHSType->isVectorType() || !RHSType->isVectorType()) {
+ Diag(TheCall->getLocStart(), diag::err_shufflevector_non_vector)
+ << SourceRange(TheCall->getArg(0)->getLocStart(),
+ TheCall->getArg(1)->getLocEnd());
+ return ExprError();
+ }
+
+ numElements = LHSType->getAs<VectorType>()->getNumElements();
+ unsigned numResElements = TheCall->getNumArgs() - 2;
+
+ // Check to see if we have a call with 2 vector arguments, the unary shuffle
+ // with mask. If so, verify that RHS is an integer vector type with the
+ // same number of elts as lhs.
+ if (TheCall->getNumArgs() == 2) {
+ if (!RHSType->hasIntegerRepresentation() ||
+ RHSType->getAs<VectorType>()->getNumElements() != numElements)
+ Diag(TheCall->getLocStart(), diag::err_shufflevector_incompatible_vector)
+ << SourceRange(TheCall->getArg(1)->getLocStart(),
+ TheCall->getArg(1)->getLocEnd());
+ numResElements = numElements;
+ }
+ else if (!Context.hasSameUnqualifiedType(LHSType, RHSType)) {
+ Diag(TheCall->getLocStart(), diag::err_shufflevector_incompatible_vector)
+ << SourceRange(TheCall->getArg(0)->getLocStart(),
+ TheCall->getArg(1)->getLocEnd());
+ return ExprError();
+ } else if (numElements != numResElements) {
+ QualType eltType = LHSType->getAs<VectorType>()->getElementType();
+ resType = Context.getVectorType(eltType, numResElements,
+ VectorType::GenericVector);
+ }
+ }
+
+ for (unsigned i = 2; i < TheCall->getNumArgs(); i++) {
+ if (TheCall->getArg(i)->isTypeDependent() ||
+ TheCall->getArg(i)->isValueDependent())
+ continue;
+
+ llvm::APSInt Result(32);
+ if (!TheCall->getArg(i)->isIntegerConstantExpr(Result, Context))
+ return ExprError(Diag(TheCall->getLocStart(),
+ diag::err_shufflevector_nonconstant_argument)
+ << TheCall->getArg(i)->getSourceRange());
+
+ if (Result.getActiveBits() > 64 || Result.getZExtValue() >= numElements*2)
+ return ExprError(Diag(TheCall->getLocStart(),
+ diag::err_shufflevector_argument_too_large)
+ << TheCall->getArg(i)->getSourceRange());
+ }
+
+ SmallVector<Expr*, 32> exprs;
+
+ for (unsigned i = 0, e = TheCall->getNumArgs(); i != e; i++) {
+ exprs.push_back(TheCall->getArg(i));
+ TheCall->setArg(i, 0);
+ }
+
+ return Owned(new (Context) ShuffleVectorExpr(Context, exprs.begin(),
+ exprs.size(), resType,
+ TheCall->getCallee()->getLocStart(),
+ TheCall->getRParenLoc()));
+}
+
+/// SemaBuiltinPrefetch - Handle __builtin_prefetch.
+// This is declared to take (const void*, ...) and can take two
+// optional constant int args.
+bool Sema::SemaBuiltinPrefetch(CallExpr *TheCall) {
+ unsigned NumArgs = TheCall->getNumArgs();
+
+ if (NumArgs > 3)
+ return Diag(TheCall->getLocEnd(),
+ diag::err_typecheck_call_too_many_args_at_most)
+ << 0 /*function call*/ << 3 << NumArgs
+ << TheCall->getSourceRange();
+
+ // Argument 0 is checked for us and the remaining arguments must be
+ // constant integers.
+ for (unsigned i = 1; i != NumArgs; ++i) {
+ Expr *Arg = TheCall->getArg(i);
+
+ llvm::APSInt Result;
+ if (SemaBuiltinConstantArg(TheCall, i, Result))
+ return true;
+
+ // FIXME: gcc issues a warning and rewrites these to 0. These
+ // seems especially odd for the third argument since the default
+ // is 3.
+ if (i == 1) {
+ if (Result.getLimitedValue() > 1)
+ return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
+ << "0" << "1" << Arg->getSourceRange();
+ } else {
+ if (Result.getLimitedValue() > 3)
+ return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
+ << "0" << "3" << Arg->getSourceRange();
+ }
+ }
+
+ return false;
+}
+
+/// SemaBuiltinConstantArg - Handle a check if argument ArgNum of CallExpr
+/// TheCall is a constant expression.
+bool Sema::SemaBuiltinConstantArg(CallExpr *TheCall, int ArgNum,
+ llvm::APSInt &Result) {
+ Expr *Arg = TheCall->getArg(ArgNum);
+ DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
+ FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl());
+
+ if (Arg->isTypeDependent() || Arg->isValueDependent()) return false;
+
+ if (!Arg->isIntegerConstantExpr(Result, Context))
+ return Diag(TheCall->getLocStart(), diag::err_constant_integer_arg_type)
+ << FDecl->getDeclName() << Arg->getSourceRange();
+
+ return false;
+}
+
+/// SemaBuiltinObjectSize - Handle __builtin_object_size(void *ptr,
+/// int type). This simply type checks that type is one of the defined
+/// constants (0-3).
+// For compatibility check 0-3, llvm only handles 0 and 2.
+bool Sema::SemaBuiltinObjectSize(CallExpr *TheCall) {
+ llvm::APSInt Result;
+
+ // Check constant-ness first.
+ if (SemaBuiltinConstantArg(TheCall, 1, Result))
+ return true;
+
+ Expr *Arg = TheCall->getArg(1);
+ if (Result.getSExtValue() < 0 || Result.getSExtValue() > 3) {
+ return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
+ << "0" << "3" << SourceRange(Arg->getLocStart(), Arg->getLocEnd());
+ }
+
+ return false;
+}
+
+/// SemaBuiltinLongjmp - Handle __builtin_longjmp(void *env[5], int val).
+/// This checks that val is a constant 1.
+bool Sema::SemaBuiltinLongjmp(CallExpr *TheCall) {
+ Expr *Arg = TheCall->getArg(1);
+ llvm::APSInt Result;
+
+ // TODO: This is less than ideal. Overload this to take a value.
+ if (SemaBuiltinConstantArg(TheCall, 1, Result))
+ return true;
+
+ if (Result != 1)
+ return Diag(TheCall->getLocStart(), diag::err_builtin_longjmp_invalid_val)
+ << SourceRange(Arg->getLocStart(), Arg->getLocEnd());
+
+ return false;
+}
+
+// Handle i > 1 ? "x" : "y", recursively.
+bool Sema::SemaCheckStringLiteral(const Expr *E, Expr **Args,
+ unsigned NumArgs, bool HasVAListArg,
+ unsigned format_idx, unsigned firstDataArg,
+ FormatStringType Type, bool inFunctionCall) {
+ tryAgain:
+ if (E->isTypeDependent() || E->isValueDependent())
+ return false;
+
+ E = E->IgnoreParenCasts();
+
+ if (E->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull))
+ // Technically -Wformat-nonliteral does not warn about this case.
+ // The behavior of printf and friends in this case is implementation
+ // dependent. Ideally if the format string cannot be null then
+ // it should have a 'nonnull' attribute in the function prototype.
+ return true;
+
+ switch (E->getStmtClass()) {
+ case Stmt::BinaryConditionalOperatorClass:
+ case Stmt::ConditionalOperatorClass: {
+ const AbstractConditionalOperator *C = cast<AbstractConditionalOperator>(E);
+ return SemaCheckStringLiteral(C->getTrueExpr(), Args, NumArgs, HasVAListArg,
+ format_idx, firstDataArg, Type,
+ inFunctionCall)
+ && SemaCheckStringLiteral(C->getFalseExpr(), Args, NumArgs, HasVAListArg,
+ format_idx, firstDataArg, Type,
+ inFunctionCall);
+ }
+
+ case Stmt::ImplicitCastExprClass: {
+ E = cast<ImplicitCastExpr>(E)->getSubExpr();
+ goto tryAgain;
+ }
+
+ case Stmt::OpaqueValueExprClass:
+ if (const Expr *src = cast<OpaqueValueExpr>(E)->getSourceExpr()) {
+ E = src;
+ goto tryAgain;
+ }
+ return false;
+
+ case Stmt::PredefinedExprClass:
+ // While __func__, etc., are technically not string literals, they
+ // cannot contain format specifiers and thus are not a security
+ // liability.
+ return true;
+
+ case Stmt::DeclRefExprClass: {
+ const DeclRefExpr *DR = cast<DeclRefExpr>(E);
+
+ // As an exception, do not flag errors for variables binding to
+ // const string literals.
+ if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
+ bool isConstant = false;
+ QualType T = DR->getType();
+
+ if (const ArrayType *AT = Context.getAsArrayType(T)) {
+ isConstant = AT->getElementType().isConstant(Context);
+ } else if (const PointerType *PT = T->getAs<PointerType>()) {
+ isConstant = T.isConstant(Context) &&
+ PT->getPointeeType().isConstant(Context);
+ } else if (T->isObjCObjectPointerType()) {
+ // In ObjC, there is usually no "const ObjectPointer" type,
+ // so don't check if the pointee type is constant.
+ isConstant = T.isConstant(Context);
+ }
+
+ if (isConstant) {
+ if (const Expr *Init = VD->getAnyInitializer())
+ return SemaCheckStringLiteral(Init, Args, NumArgs,
+ HasVAListArg, format_idx, firstDataArg,
+ Type, /*inFunctionCall*/false);
+ }
+
+ // For vprintf* functions (i.e., HasVAListArg==true), we add a
+ // special check to see if the format string is a function parameter
+ // of the function calling the printf function. If the function
+ // has an attribute indicating it is a printf-like function, then we
+ // should suppress warnings concerning non-literals being used in a call
+ // to a vprintf function. For example:
+ //
+ // void
+ // logmessage(char const *fmt __attribute__ (format (printf, 1, 2)), ...){
+ // va_list ap;
+ // va_start(ap, fmt);
+ // vprintf(fmt, ap); // Do NOT emit a warning about "fmt".
+ // ...
+ //
+ if (HasVAListArg) {
+ if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(VD)) {
+ if (const NamedDecl *ND = dyn_cast<NamedDecl>(PV->getDeclContext())) {
+ int PVIndex = PV->getFunctionScopeIndex() + 1;
+ for (specific_attr_iterator<FormatAttr>
+ i = ND->specific_attr_begin<FormatAttr>(),
+ e = ND->specific_attr_end<FormatAttr>(); i != e ; ++i) {
+ FormatAttr *PVFormat = *i;
+ // adjust for implicit parameter
+ if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND))
+ if (MD->isInstance())
+ ++PVIndex;
+ // We also check if the formats are compatible.
+ // We can't pass a 'scanf' string to a 'printf' function.
+ if (PVIndex == PVFormat->getFormatIdx() &&
+ Type == GetFormatStringType(PVFormat))
+ return true;
+ }
+ }
+ }
+ }
+ }
+
+ return false;
+ }
+
+ case Stmt::CallExprClass:
+ case Stmt::CXXMemberCallExprClass: {
+ const CallExpr *CE = cast<CallExpr>(E);
+ if (const NamedDecl *ND = dyn_cast_or_null<NamedDecl>(CE->getCalleeDecl())) {
+ if (const FormatArgAttr *FA = ND->getAttr<FormatArgAttr>()) {
+ unsigned ArgIndex = FA->getFormatIdx();
+ if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND))
+ if (MD->isInstance())
+ --ArgIndex;
+ const Expr *Arg = CE->getArg(ArgIndex - 1);
+
+ return SemaCheckStringLiteral(Arg, Args, NumArgs, HasVAListArg,
+ format_idx, firstDataArg, Type,
+ inFunctionCall);
+ }
+ }
+
+ return false;
+ }
+ case Stmt::ObjCStringLiteralClass:
+ case Stmt::StringLiteralClass: {
+ const StringLiteral *StrE = NULL;
+
+ if (const ObjCStringLiteral *ObjCFExpr = dyn_cast<ObjCStringLiteral>(E))
+ StrE = ObjCFExpr->getString();
+ else
+ StrE = cast<StringLiteral>(E);
+
+ if (StrE) {
+ CheckFormatString(StrE, E, Args, NumArgs, HasVAListArg, format_idx,
+ firstDataArg, Type, inFunctionCall);
+ return true;
+ }
+
+ return false;
+ }
+
+ default:
+ return false;
+ }
+}
+
+void
+Sema::CheckNonNullArguments(const NonNullAttr *NonNull,
+ const Expr * const *ExprArgs,
+ SourceLocation CallSiteLoc) {
+ for (NonNullAttr::args_iterator i = NonNull->args_begin(),
+ e = NonNull->args_end();
+ i != e; ++i) {
+ const Expr *ArgExpr = ExprArgs[*i];
+ if (ArgExpr->isNullPointerConstant(Context,
+ Expr::NPC_ValueDependentIsNotNull))
+ Diag(CallSiteLoc, diag::warn_null_arg) << ArgExpr->getSourceRange();
+ }
+}
+
+Sema::FormatStringType Sema::GetFormatStringType(const FormatAttr *Format) {
+ return llvm::StringSwitch<FormatStringType>(Format->getType())
+ .Case("scanf", FST_Scanf)
+ .Cases("printf", "printf0", FST_Printf)
+ .Cases("NSString", "CFString", FST_NSString)
+ .Case("strftime", FST_Strftime)
+ .Case("strfmon", FST_Strfmon)
+ .Cases("kprintf", "cmn_err", "vcmn_err", "zcmn_err", FST_Kprintf)
+ .Default(FST_Unknown);
+}
+
+/// CheckPrintfScanfArguments - Check calls to printf and scanf (and similar
+/// functions) for correct use of format strings.
+void Sema::CheckFormatArguments(const FormatAttr *Format, CallExpr *TheCall) {
+ bool IsCXXMember = false;
+ // The way the format attribute works in GCC, the implicit this argument
+ // of member functions is counted. However, it doesn't appear in our own
+ // lists, so decrement format_idx in that case.
+ IsCXXMember = isa<CXXMemberCallExpr>(TheCall);
+ CheckFormatArguments(Format, TheCall->getArgs(), TheCall->getNumArgs(),
+ IsCXXMember, TheCall->getRParenLoc(),
+ TheCall->getCallee()->getSourceRange());
+}
+
+void Sema::CheckFormatArguments(const FormatAttr *Format, Expr **Args,
+ unsigned NumArgs, bool IsCXXMember,
+ SourceLocation Loc, SourceRange Range) {
+ bool HasVAListArg = Format->getFirstArg() == 0;
+ unsigned format_idx = Format->getFormatIdx() - 1;
+ unsigned firstDataArg = HasVAListArg ? 0 : Format->getFirstArg() - 1;
+ if (IsCXXMember) {
+ if (format_idx == 0)
+ return;
+ --format_idx;
+ if(firstDataArg != 0)
+ --firstDataArg;
+ }
+ CheckFormatArguments(Args, NumArgs, HasVAListArg, format_idx,
+ firstDataArg, GetFormatStringType(Format), Loc, Range);
+}
+
+void Sema::CheckFormatArguments(Expr **Args, unsigned NumArgs,
+ bool HasVAListArg, unsigned format_idx,
+ unsigned firstDataArg, FormatStringType Type,
+ SourceLocation Loc, SourceRange Range) {
+ // CHECK: printf/scanf-like function is called with no format string.
+ if (format_idx >= NumArgs) {
+ Diag(Loc, diag::warn_missing_format_string) << Range;
+ return;
+ }
+
+ const Expr *OrigFormatExpr = Args[format_idx]->IgnoreParenCasts();
+
+ // CHECK: format string is not a string literal.
+ //
+ // Dynamically generated format strings are difficult to
+ // automatically vet at compile time. Requiring that format strings
+ // are string literals: (1) permits the checking of format strings by
+ // the compiler and thereby (2) can practically remove the source of
+ // many format string exploits.
+
+ // Format string can be either ObjC string (e.g. @"%d") or
+ // C string (e.g. "%d")
+ // ObjC string uses the same format specifiers as C string, so we can use
+ // the same format string checking logic for both ObjC and C strings.
+ if (SemaCheckStringLiteral(OrigFormatExpr, Args, NumArgs, HasVAListArg,
+ format_idx, firstDataArg, Type))
+ return; // Literal format string found, check done!
+
+ // Strftime is particular as it always uses a single 'time' argument,
+ // so it is safe to pass a non-literal string.
+ if (Type == FST_Strftime)
+ return;
+
+ // Do not emit diag when the string param is a macro expansion and the
+ // format is either NSString or CFString. This is a hack to prevent
+ // diag when using the NSLocalizedString and CFCopyLocalizedString macros
+ // which are usually used in place of NS and CF string literals.
+ if (Type == FST_NSString && Args[format_idx]->getLocStart().isMacroID())
+ return;
+
+ // If there are no arguments specified, warn with -Wformat-security, otherwise
+ // warn only with -Wformat-nonliteral.
+ if (NumArgs == format_idx+1)
+ Diag(Args[format_idx]->getLocStart(),
+ diag::warn_format_nonliteral_noargs)
+ << OrigFormatExpr->getSourceRange();
+ else
+ Diag(Args[format_idx]->getLocStart(),
+ diag::warn_format_nonliteral)
+ << OrigFormatExpr->getSourceRange();
+}
+
+namespace {
+class CheckFormatHandler : public analyze_format_string::FormatStringHandler {
+protected:
+ Sema &S;
+ const StringLiteral *FExpr;
+ const Expr *OrigFormatExpr;
+ const unsigned FirstDataArg;
+ const unsigned NumDataArgs;
+ const bool IsObjCLiteral;
+ const char *Beg; // Start of format string.
+ const bool HasVAListArg;
+ const Expr * const *Args;
+ const unsigned NumArgs;
+ unsigned FormatIdx;
+ llvm::BitVector CoveredArgs;
+ bool usesPositionalArgs;
+ bool atFirstArg;
+ bool inFunctionCall;
+public:
+ CheckFormatHandler(Sema &s, const StringLiteral *fexpr,
+ const Expr *origFormatExpr, unsigned firstDataArg,
+ unsigned numDataArgs, bool isObjCLiteral,
+ const char *beg, bool hasVAListArg,
+ Expr **args, unsigned numArgs,
+ unsigned formatIdx, bool inFunctionCall)
+ : S(s), FExpr(fexpr), OrigFormatExpr(origFormatExpr),
+ FirstDataArg(firstDataArg),
+ NumDataArgs(numDataArgs),
+ IsObjCLiteral(isObjCLiteral), Beg(beg),
+ HasVAListArg(hasVAListArg),
+ Args(args), NumArgs(numArgs), FormatIdx(formatIdx),
+ usesPositionalArgs(false), atFirstArg(true),
+ inFunctionCall(inFunctionCall) {
+ CoveredArgs.resize(numDataArgs);
+ CoveredArgs.reset();
+ }
+
+ void DoneProcessing();
+
+ void HandleIncompleteSpecifier(const char *startSpecifier,
+ unsigned specifierLen);
+
+ void HandleNonStandardLengthModifier(
+ const analyze_format_string::LengthModifier &LM,
+ const char *startSpecifier, unsigned specifierLen);
+
+ void HandleNonStandardConversionSpecifier(
+ const analyze_format_string::ConversionSpecifier &CS,
+ const char *startSpecifier, unsigned specifierLen);
+
+ void HandleNonStandardConversionSpecification(
+ const analyze_format_string::LengthModifier &LM,
+ const analyze_format_string::ConversionSpecifier &CS,
+ const char *startSpecifier, unsigned specifierLen);
+
+ virtual void HandlePosition(const char *startPos, unsigned posLen);
+
+ virtual void HandleInvalidPosition(const char *startSpecifier,
+ unsigned specifierLen,
+ analyze_format_string::PositionContext p);
+
+ virtual void HandleZeroPosition(const char *startPos, unsigned posLen);
+
+ void HandleNullChar(const char *nullCharacter);
+
+ template <typename Range>
+ static void EmitFormatDiagnostic(Sema &S, bool inFunctionCall,
+ const Expr *ArgumentExpr,
+ PartialDiagnostic PDiag,
+ SourceLocation StringLoc,
+ bool IsStringLocation, Range StringRange,
+ FixItHint Fixit = FixItHint());
+
+protected:
+ bool HandleInvalidConversionSpecifier(unsigned argIndex, SourceLocation Loc,
+ const char *startSpec,
+ unsigned specifierLen,
+ const char *csStart, unsigned csLen);
+
+ void HandlePositionalNonpositionalArgs(SourceLocation Loc,
+ const char *startSpec,
+ unsigned specifierLen);
+
+ SourceRange getFormatStringRange();
+ CharSourceRange getSpecifierRange(const char *startSpecifier,
+ unsigned specifierLen);
+ SourceLocation getLocationOfByte(const char *x);
+
+ const Expr *getDataArg(unsigned i) const;
+
+ bool CheckNumArgs(const analyze_format_string::FormatSpecifier &FS,
+ const analyze_format_string::ConversionSpecifier &CS,
+ const char *startSpecifier, unsigned specifierLen,
+ unsigned argIndex);
+
+ template <typename Range>
+ void EmitFormatDiagnostic(PartialDiagnostic PDiag, SourceLocation StringLoc,
+ bool IsStringLocation, Range StringRange,
+ FixItHint Fixit = FixItHint());
+
+ void CheckPositionalAndNonpositionalArgs(
+ const analyze_format_string::FormatSpecifier *FS);
+};
+}
+
+SourceRange CheckFormatHandler::getFormatStringRange() {
+ return OrigFormatExpr->getSourceRange();
+}
+
+CharSourceRange CheckFormatHandler::
+getSpecifierRange(const char *startSpecifier, unsigned specifierLen) {
+ SourceLocation Start = getLocationOfByte(startSpecifier);
+ SourceLocation End = getLocationOfByte(startSpecifier + specifierLen - 1);
+
+ // Advance the end SourceLocation by one due to half-open ranges.
+ End = End.getLocWithOffset(1);
+
+ return CharSourceRange::getCharRange(Start, End);
+}
+
+SourceLocation CheckFormatHandler::getLocationOfByte(const char *x) {
+ return S.getLocationOfStringLiteralByte(FExpr, x - Beg);
+}
+
+void CheckFormatHandler::HandleIncompleteSpecifier(const char *startSpecifier,
+ unsigned specifierLen){
+ EmitFormatDiagnostic(S.PDiag(diag::warn_printf_incomplete_specifier),
+ getLocationOfByte(startSpecifier),
+ /*IsStringLocation*/true,
+ getSpecifierRange(startSpecifier, specifierLen));
+}
+
+void CheckFormatHandler::HandleNonStandardLengthModifier(
+ const analyze_format_string::LengthModifier &LM,
+ const char *startSpecifier, unsigned specifierLen) {
+ EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard) << LM.toString()
+ << 0,
+ getLocationOfByte(LM.getStart()),
+ /*IsStringLocation*/true,
+ getSpecifierRange(startSpecifier, specifierLen));
+}
+
+void CheckFormatHandler::HandleNonStandardConversionSpecifier(
+ const analyze_format_string::ConversionSpecifier &CS,
+ const char *startSpecifier, unsigned specifierLen) {
+ EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard) << CS.toString()
+ << 1,
+ getLocationOfByte(CS.getStart()),
+ /*IsStringLocation*/true,
+ getSpecifierRange(startSpecifier, specifierLen));
+}
+
+void CheckFormatHandler::HandleNonStandardConversionSpecification(
+ const analyze_format_string::LengthModifier &LM,
+ const analyze_format_string::ConversionSpecifier &CS,
+ const char *startSpecifier, unsigned specifierLen) {
+ EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard_conversion_spec)
+ << LM.toString() << CS.toString(),
+ getLocationOfByte(LM.getStart()),
+ /*IsStringLocation*/true,
+ getSpecifierRange(startSpecifier, specifierLen));
+}
+
+void CheckFormatHandler::HandlePosition(const char *startPos,
+ unsigned posLen) {
+ EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard_positional_arg),
+ getLocationOfByte(startPos),
+ /*IsStringLocation*/true,
+ getSpecifierRange(startPos, posLen));
+}
+
+void
+CheckFormatHandler::HandleInvalidPosition(const char *startPos, unsigned posLen,
+ analyze_format_string::PositionContext p) {
+ EmitFormatDiagnostic(S.PDiag(diag::warn_format_invalid_positional_specifier)
+ << (unsigned) p,
+ getLocationOfByte(startPos), /*IsStringLocation*/true,
+ getSpecifierRange(startPos, posLen));
+}
+
+void CheckFormatHandler::HandleZeroPosition(const char *startPos,
+ unsigned posLen) {
+ EmitFormatDiagnostic(S.PDiag(diag::warn_format_zero_positional_specifier),
+ getLocationOfByte(startPos),
+ /*IsStringLocation*/true,
+ getSpecifierRange(startPos, posLen));
+}
+
+void CheckFormatHandler::HandleNullChar(const char *nullCharacter) {
+ if (!IsObjCLiteral) {
+ // The presence of a null character is likely an error.
+ EmitFormatDiagnostic(
+ S.PDiag(diag::warn_printf_format_string_contains_null_char),
+ getLocationOfByte(nullCharacter), /*IsStringLocation*/true,
+ getFormatStringRange());
+ }
+}
+
+const Expr *CheckFormatHandler::getDataArg(unsigned i) const {
+ return Args[FirstDataArg + i];
+}
+
+void CheckFormatHandler::DoneProcessing() {
+ // Does the number of data arguments exceed the number of
+ // format conversions in the format string?
+ if (!HasVAListArg) {
+ // Find any arguments that weren't covered.
+ CoveredArgs.flip();
+ signed notCoveredArg = CoveredArgs.find_first();
+ if (notCoveredArg >= 0) {
+ assert((unsigned)notCoveredArg < NumDataArgs);
+ EmitFormatDiagnostic(S.PDiag(diag::warn_printf_data_arg_not_used),
+ getDataArg((unsigned) notCoveredArg)->getLocStart(),
+ /*IsStringLocation*/false, getFormatStringRange());
+ }
+ }
+}
+
+bool
+CheckFormatHandler::HandleInvalidConversionSpecifier(unsigned argIndex,
+ SourceLocation Loc,
+ const char *startSpec,
+ unsigned specifierLen,
+ const char *csStart,
+ unsigned csLen) {
+
+ bool keepGoing = true;
+ if (argIndex < NumDataArgs) {
+ // Consider the argument coverered, even though the specifier doesn't
+ // make sense.
+ CoveredArgs.set(argIndex);
+ }
+ else {
+ // If argIndex exceeds the number of data arguments we
+ // don't issue a warning because that is just a cascade of warnings (and
+ // they may have intended '%%' anyway). We don't want to continue processing
+ // the format string after this point, however, as we will like just get
+ // gibberish when trying to match arguments.
+ keepGoing = false;
+ }
+
+ EmitFormatDiagnostic(S.PDiag(diag::warn_format_invalid_conversion)
+ << StringRef(csStart, csLen),
+ Loc, /*IsStringLocation*/true,
+ getSpecifierRange(startSpec, specifierLen));
+
+ return keepGoing;
+}
+
+void
+CheckFormatHandler::HandlePositionalNonpositionalArgs(SourceLocation Loc,
+ const char *startSpec,
+ unsigned specifierLen) {
+ EmitFormatDiagnostic(
+ S.PDiag(diag::warn_format_mix_positional_nonpositional_args),
+ Loc, /*isStringLoc*/true, getSpecifierRange(startSpec, specifierLen));
+}
+
+bool
+CheckFormatHandler::CheckNumArgs(
+ const analyze_format_string::FormatSpecifier &FS,
+ const analyze_format_string::ConversionSpecifier &CS,
+ const char *startSpecifier, unsigned specifierLen, unsigned argIndex) {
+
+ if (argIndex >= NumDataArgs) {
+ PartialDiagnostic PDiag = FS.usesPositionalArg()
+ ? (S.PDiag(diag::warn_printf_positional_arg_exceeds_data_args)
+ << (argIndex+1) << NumDataArgs)
+ : S.PDiag(diag::warn_printf_insufficient_data_args);
+ EmitFormatDiagnostic(
+ PDiag, getLocationOfByte(CS.getStart()), /*IsStringLocation*/true,
+ getSpecifierRange(startSpecifier, specifierLen));
+ return false;
+ }
+ return true;
+}
+
+template<typename Range>
+void CheckFormatHandler::EmitFormatDiagnostic(PartialDiagnostic PDiag,
+ SourceLocation Loc,
+ bool IsStringLocation,
+ Range StringRange,
+ FixItHint FixIt) {
+ EmitFormatDiagnostic(S, inFunctionCall, Args[FormatIdx], PDiag,
+ Loc, IsStringLocation, StringRange, FixIt);
+}
+
+/// \brief If the format string is not within the funcion call, emit a note
+/// so that the function call and string are in diagnostic messages.
+///
+/// \param inFunctionCall if true, the format string is within the function
+/// call and only one diagnostic message will be produced. Otherwise, an
+/// extra note will be emitted pointing to location of the format string.
+///
+/// \param ArgumentExpr the expression that is passed as the format string
+/// argument in the function call. Used for getting locations when two
+/// diagnostics are emitted.
+///
+/// \param PDiag the callee should already have provided any strings for the
+/// diagnostic message. This function only adds locations and fixits
+/// to diagnostics.
+///
+/// \param Loc primary location for diagnostic. If two diagnostics are
+/// required, one will be at Loc and a new SourceLocation will be created for
+/// the other one.
+///
+/// \param IsStringLocation if true, Loc points to the format string should be
+/// used for the note. Otherwise, Loc points to the argument list and will
+/// be used with PDiag.
+///
+/// \param StringRange some or all of the string to highlight. This is
+/// templated so it can accept either a CharSourceRange or a SourceRange.
+///
+/// \param Fixit optional fix it hint for the format string.
+template<typename Range>
+void CheckFormatHandler::EmitFormatDiagnostic(Sema &S, bool InFunctionCall,
+ const Expr *ArgumentExpr,
+ PartialDiagnostic PDiag,
+ SourceLocation Loc,
+ bool IsStringLocation,
+ Range StringRange,
+ FixItHint FixIt) {
+ if (InFunctionCall)
+ S.Diag(Loc, PDiag) << StringRange << FixIt;
+ else {
+ S.Diag(IsStringLocation ? ArgumentExpr->getExprLoc() : Loc, PDiag)
+ << ArgumentExpr->getSourceRange();
+ S.Diag(IsStringLocation ? Loc : StringRange.getBegin(),
+ diag::note_format_string_defined)
+ << StringRange << FixIt;
+ }
+}
+
+//===--- CHECK: Printf format string checking ------------------------------===//
+
+namespace {
+class CheckPrintfHandler : public CheckFormatHandler {
+public:
+ CheckPrintfHandler(Sema &s, const StringLiteral *fexpr,
+ const Expr *origFormatExpr, unsigned firstDataArg,
+ unsigned numDataArgs, bool isObjCLiteral,
+ const char *beg, bool hasVAListArg,
+ Expr **Args, unsigned NumArgs,
+ unsigned formatIdx, bool inFunctionCall)
+ : CheckFormatHandler(s, fexpr, origFormatExpr, firstDataArg,
+ numDataArgs, isObjCLiteral, beg, hasVAListArg,
+ Args, NumArgs, formatIdx, inFunctionCall) {}
+
+
+ bool HandleInvalidPrintfConversionSpecifier(
+ const analyze_printf::PrintfSpecifier &FS,
+ const char *startSpecifier,
+ unsigned specifierLen);
+
+ bool HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier &FS,
+ const char *startSpecifier,
+ unsigned specifierLen);
+
+ bool HandleAmount(const analyze_format_string::OptionalAmount &Amt, unsigned k,
+ const char *startSpecifier, unsigned specifierLen);
+ void HandleInvalidAmount(const analyze_printf::PrintfSpecifier &FS,
+ const analyze_printf::OptionalAmount &Amt,
+ unsigned type,
+ const char *startSpecifier, unsigned specifierLen);
+ void HandleFlag(const analyze_printf::PrintfSpecifier &FS,
+ const analyze_printf::OptionalFlag &flag,
+ const char *startSpecifier, unsigned specifierLen);
+ void HandleIgnoredFlag(const analyze_printf::PrintfSpecifier &FS,
+ const analyze_printf::OptionalFlag &ignoredFlag,
+ const analyze_printf::OptionalFlag &flag,
+ const char *startSpecifier, unsigned specifierLen);
+};
+}
+
+bool CheckPrintfHandler::HandleInvalidPrintfConversionSpecifier(
+ const analyze_printf::PrintfSpecifier &FS,
+ const char *startSpecifier,
+ unsigned specifierLen) {
+ const analyze_printf::PrintfConversionSpecifier &CS =
+ FS.getConversionSpecifier();
+
+ return HandleInvalidConversionSpecifier(FS.getArgIndex(),
+ getLocationOfByte(CS.getStart()),
+ startSpecifier, specifierLen,
+ CS.getStart(), CS.getLength());
+}
+
+bool CheckPrintfHandler::HandleAmount(
+ const analyze_format_string::OptionalAmount &Amt,
+ unsigned k, const char *startSpecifier,
+ unsigned specifierLen) {
+
+ if (Amt.hasDataArgument()) {
+ if (!HasVAListArg) {
+ unsigned argIndex = Amt.getArgIndex();
+ if (argIndex >= NumDataArgs) {
+ EmitFormatDiagnostic(S.PDiag(diag::warn_printf_asterisk_missing_arg)
+ << k,
+ getLocationOfByte(Amt.getStart()),
+ /*IsStringLocation*/true,
+ getSpecifierRange(startSpecifier, specifierLen));
+ // Don't do any more checking. We will just emit
+ // spurious errors.
+ return false;
+ }
+
+ // Type check the data argument. It should be an 'int'.
+ // Although not in conformance with C99, we also allow the argument to be
+ // an 'unsigned int' as that is a reasonably safe case. GCC also
+ // doesn't emit a warning for that case.
+ CoveredArgs.set(argIndex);
+ const Expr *Arg = getDataArg(argIndex);
+ QualType T = Arg->getType();
+
+ const analyze_printf::ArgTypeResult &ATR = Amt.getArgType(S.Context);
+ assert(ATR.isValid());
+
+ if (!ATR.matchesType(S.Context, T)) {
+ EmitFormatDiagnostic(S.PDiag(diag::warn_printf_asterisk_wrong_type)
+ << k << ATR.getRepresentativeTypeName(S.Context)
+ << T << Arg->getSourceRange(),
+ getLocationOfByte(Amt.getStart()),
+ /*IsStringLocation*/true,
+ getSpecifierRange(startSpecifier, specifierLen));
+ // Don't do any more checking. We will just emit
+ // spurious errors.
+ return false;
+ }
+ }
+ }
+ return true;
+}
+
+void CheckPrintfHandler::HandleInvalidAmount(
+ const analyze_printf::PrintfSpecifier &FS,
+ const analyze_printf::OptionalAmount &Amt,
+ unsigned type,
+ const char *startSpecifier,
+ unsigned specifierLen) {
+ const analyze_printf::PrintfConversionSpecifier &CS =
+ FS.getConversionSpecifier();
+
+ FixItHint fixit =
+ Amt.getHowSpecified() == analyze_printf::OptionalAmount::Constant
+ ? FixItHint::CreateRemoval(getSpecifierRange(Amt.getStart(),
+ Amt.getConstantLength()))
+ : FixItHint();
+
+ EmitFormatDiagnostic(S.PDiag(diag::warn_printf_nonsensical_optional_amount)
+ << type << CS.toString(),
+ getLocationOfByte(Amt.getStart()),
+ /*IsStringLocation*/true,
+ getSpecifierRange(startSpecifier, specifierLen),
+ fixit);
+}
+
+void CheckPrintfHandler::HandleFlag(const analyze_printf::PrintfSpecifier &FS,
+ const analyze_printf::OptionalFlag &flag,
+ const char *startSpecifier,
+ unsigned specifierLen) {
+ // Warn about pointless flag with a fixit removal.
+ const analyze_printf::PrintfConversionSpecifier &CS =
+ FS.getConversionSpecifier();
+ EmitFormatDiagnostic(S.PDiag(diag::warn_printf_nonsensical_flag)
+ << flag.toString() << CS.toString(),
+ getLocationOfByte(flag.getPosition()),
+ /*IsStringLocation*/true,
+ getSpecifierRange(startSpecifier, specifierLen),
+ FixItHint::CreateRemoval(
+ getSpecifierRange(flag.getPosition(), 1)));
+}
+
+void CheckPrintfHandler::HandleIgnoredFlag(
+ const analyze_printf::PrintfSpecifier &FS,
+ const analyze_printf::OptionalFlag &ignoredFlag,
+ const analyze_printf::OptionalFlag &flag,
+ const char *startSpecifier,
+ unsigned specifierLen) {
+ // Warn about ignored flag with a fixit removal.
+ EmitFormatDiagnostic(S.PDiag(diag::warn_printf_ignored_flag)
+ << ignoredFlag.toString() << flag.toString(),
+ getLocationOfByte(ignoredFlag.getPosition()),
+ /*IsStringLocation*/true,
+ getSpecifierRange(startSpecifier, specifierLen),
+ FixItHint::CreateRemoval(
+ getSpecifierRange(ignoredFlag.getPosition(), 1)));
+}
+
+bool
+CheckPrintfHandler::HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier
+ &FS,
+ const char *startSpecifier,
+ unsigned specifierLen) {
+
+ using namespace analyze_format_string;
+ using namespace analyze_printf;
+ const PrintfConversionSpecifier &CS = FS.getConversionSpecifier();
+
+ if (FS.consumesDataArgument()) {
+ if (atFirstArg) {
+ atFirstArg = false;
+ usesPositionalArgs = FS.usesPositionalArg();
+ }
+ else if (usesPositionalArgs != FS.usesPositionalArg()) {
+ HandlePositionalNonpositionalArgs(getLocationOfByte(CS.getStart()),
+ startSpecifier, specifierLen);
+ return false;
+ }
+ }
+
+ // First check if the field width, precision, and conversion specifier
+ // have matching data arguments.
+ if (!HandleAmount(FS.getFieldWidth(), /* field width */ 0,
+ startSpecifier, specifierLen)) {
+ return false;
+ }
+
+ if (!HandleAmount(FS.getPrecision(), /* precision */ 1,
+ startSpecifier, specifierLen)) {
+ return false;
+ }
+
+ if (!CS.consumesDataArgument()) {
+ // FIXME: Technically specifying a precision or field width here
+ // makes no sense. Worth issuing a warning at some point.
+ return true;
+ }
+
+ // Consume the argument.
+ unsigned argIndex = FS.getArgIndex();
+ if (argIndex < NumDataArgs) {
+ // The check to see if the argIndex is valid will come later.
+ // We set the bit here because we may exit early from this
+ // function if we encounter some other error.
+ CoveredArgs.set(argIndex);
+ }
+
+ // Check for using an Objective-C specific conversion specifier
+ // in a non-ObjC literal.
+ if (!IsObjCLiteral && CS.isObjCArg()) {
+ return HandleInvalidPrintfConversionSpecifier(FS, startSpecifier,
+ specifierLen);
+ }
+
+ // Check for invalid use of field width
+ if (!FS.hasValidFieldWidth()) {
+ HandleInvalidAmount(FS, FS.getFieldWidth(), /* field width */ 0,
+ startSpecifier, specifierLen);
+ }
+
+ // Check for invalid use of precision
+ if (!FS.hasValidPrecision()) {
+ HandleInvalidAmount(FS, FS.getPrecision(), /* precision */ 1,
+ startSpecifier, specifierLen);
+ }
+
+ // Check each flag does not conflict with any other component.
+ if (!FS.hasValidThousandsGroupingPrefix())
+ HandleFlag(FS, FS.hasThousandsGrouping(), startSpecifier, specifierLen);
+ if (!FS.hasValidLeadingZeros())
+ HandleFlag(FS, FS.hasLeadingZeros(), startSpecifier, specifierLen);
+ if (!FS.hasValidPlusPrefix())
+ HandleFlag(FS, FS.hasPlusPrefix(), startSpecifier, specifierLen);
+ if (!FS.hasValidSpacePrefix())
+ HandleFlag(FS, FS.hasSpacePrefix(), startSpecifier, specifierLen);
+ if (!FS.hasValidAlternativeForm())
+ HandleFlag(FS, FS.hasAlternativeForm(), startSpecifier, specifierLen);
+ if (!FS.hasValidLeftJustified())
+ HandleFlag(FS, FS.isLeftJustified(), startSpecifier, specifierLen);
+
+ // Check that flags are not ignored by another flag
+ if (FS.hasSpacePrefix() && FS.hasPlusPrefix()) // ' ' ignored by '+'
+ HandleIgnoredFlag(FS, FS.hasSpacePrefix(), FS.hasPlusPrefix(),
+ startSpecifier, specifierLen);
+ if (FS.hasLeadingZeros() && FS.isLeftJustified()) // '0' ignored by '-'
+ HandleIgnoredFlag(FS, FS.hasLeadingZeros(), FS.isLeftJustified(),
+ startSpecifier, specifierLen);
+
+ // Check the length modifier is valid with the given conversion specifier.
+ const LengthModifier &LM = FS.getLengthModifier();
+ if (!FS.hasValidLengthModifier())
+ EmitFormatDiagnostic(S.PDiag(diag::warn_format_nonsensical_length)
+ << LM.toString() << CS.toString(),
+ getLocationOfByte(LM.getStart()),
+ /*IsStringLocation*/true,
+ getSpecifierRange(startSpecifier, specifierLen),
+ FixItHint::CreateRemoval(
+ getSpecifierRange(LM.getStart(),
+ LM.getLength())));
+ if (!FS.hasStandardLengthModifier())
+ HandleNonStandardLengthModifier(LM, startSpecifier, specifierLen);
+ if (!FS.hasStandardConversionSpecifier(S.getLangOpts()))
+ HandleNonStandardConversionSpecifier(CS, startSpecifier, specifierLen);
+ if (!FS.hasStandardLengthConversionCombination())
+ HandleNonStandardConversionSpecification(LM, CS, startSpecifier,
+ specifierLen);
+
+ // Are we using '%n'?
+ if (CS.getKind() == ConversionSpecifier::nArg) {
+ // Issue a warning about this being a possible security issue.
+ EmitFormatDiagnostic(S.PDiag(diag::warn_printf_write_back),
+ getLocationOfByte(CS.getStart()),
+ /*IsStringLocation*/true,
+ getSpecifierRange(startSpecifier, specifierLen));
+ // Continue checking the other format specifiers.
+ return true;
+ }
+
+ // The remaining checks depend on the data arguments.
+ if (HasVAListArg)
+ return true;
+
+ if (!CheckNumArgs(FS, CS, startSpecifier, specifierLen, argIndex))
+ return false;
+
+ // Now type check the data expression that matches the
+ // format specifier.
+ const Expr *Ex = getDataArg(argIndex);
+ const analyze_printf::ArgTypeResult &ATR = FS.getArgType(S.Context,
+ IsObjCLiteral);
+ if (ATR.isValid() && !ATR.matchesType(S.Context, Ex->getType())) {
+ // Check if we didn't match because of an implicit cast from a 'char'
+ // or 'short' to an 'int'. This is done because printf is a varargs
+ // function.
+ if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Ex))
+ if (ICE->getType() == S.Context.IntTy) {
+ // All further checking is done on the subexpression.
+ Ex = ICE->getSubExpr();
+ if (ATR.matchesType(S.Context, Ex->getType()))
+ return true;
+ }
+
+ // We may be able to offer a FixItHint if it is a supported type.
+ PrintfSpecifier fixedFS = FS;
+ bool success = fixedFS.fixType(Ex->getType(), S.getLangOpts(),
+ S.Context, IsObjCLiteral);
+
+ if (success) {
+ // Get the fix string from the fixed format specifier
+ SmallString<128> buf;
+ llvm::raw_svector_ostream os(buf);
+ fixedFS.toString(os);
+
+ EmitFormatDiagnostic(
+ S.PDiag(diag::warn_printf_conversion_argument_type_mismatch)
+ << ATR.getRepresentativeTypeName(S.Context) << Ex->getType()
+ << Ex->getSourceRange(),
+ getLocationOfByte(CS.getStart()),
+ /*IsStringLocation*/true,
+ getSpecifierRange(startSpecifier, specifierLen),
+ FixItHint::CreateReplacement(
+ getSpecifierRange(startSpecifier, specifierLen),
+ os.str()));
+ }
+ else {
+ EmitFormatDiagnostic(
+ S.PDiag(diag::warn_printf_conversion_argument_type_mismatch)
+ << ATR.getRepresentativeTypeName(S.Context) << Ex->getType()
+ << getSpecifierRange(startSpecifier, specifierLen)
+ << Ex->getSourceRange(),
+ getLocationOfByte(CS.getStart()),
+ true,
+ getSpecifierRange(startSpecifier, specifierLen));
+ }
+ }
+
+ return true;
+}
+
+//===--- CHECK: Scanf format string checking ------------------------------===//
+
+namespace {
+class CheckScanfHandler : public CheckFormatHandler {
+public:
+ CheckScanfHandler(Sema &s, const StringLiteral *fexpr,
+ const Expr *origFormatExpr, unsigned firstDataArg,
+ unsigned numDataArgs, bool isObjCLiteral,
+ const char *beg, bool hasVAListArg,
+ Expr **Args, unsigned NumArgs,
+ unsigned formatIdx, bool inFunctionCall)
+ : CheckFormatHandler(s, fexpr, origFormatExpr, firstDataArg,
+ numDataArgs, isObjCLiteral, beg, hasVAListArg,
+ Args, NumArgs, formatIdx, inFunctionCall) {}
+
+ bool HandleScanfSpecifier(const analyze_scanf::ScanfSpecifier &FS,
+ const char *startSpecifier,
+ unsigned specifierLen);
+
+ bool HandleInvalidScanfConversionSpecifier(
+ const analyze_scanf::ScanfSpecifier &FS,
+ const char *startSpecifier,
+ unsigned specifierLen);
+
+ void HandleIncompleteScanList(const char *start, const char *end);
+};
+}
+
+void CheckScanfHandler::HandleIncompleteScanList(const char *start,
+ const char *end) {
+ EmitFormatDiagnostic(S.PDiag(diag::warn_scanf_scanlist_incomplete),
+ getLocationOfByte(end), /*IsStringLocation*/true,
+ getSpecifierRange(start, end - start));
+}
+
+bool CheckScanfHandler::HandleInvalidScanfConversionSpecifier(
+ const analyze_scanf::ScanfSpecifier &FS,
+ const char *startSpecifier,
+ unsigned specifierLen) {
+
+ const analyze_scanf::ScanfConversionSpecifier &CS =
+ FS.getConversionSpecifier();
+
+ return HandleInvalidConversionSpecifier(FS.getArgIndex(),
+ getLocationOfByte(CS.getStart()),
+ startSpecifier, specifierLen,
+ CS.getStart(), CS.getLength());
+}
+
+bool CheckScanfHandler::HandleScanfSpecifier(
+ const analyze_scanf::ScanfSpecifier &FS,
+ const char *startSpecifier,
+ unsigned specifierLen) {
+
+ using namespace analyze_scanf;
+ using namespace analyze_format_string;
+
+ const ScanfConversionSpecifier &CS = FS.getConversionSpecifier();
+
+ // Handle case where '%' and '*' don't consume an argument. These shouldn't
+ // be used to decide if we are using positional arguments consistently.
+ if (FS.consumesDataArgument()) {
+ if (atFirstArg) {
+ atFirstArg = false;
+ usesPositionalArgs = FS.usesPositionalArg();
+ }
+ else if (usesPositionalArgs != FS.usesPositionalArg()) {
+ HandlePositionalNonpositionalArgs(getLocationOfByte(CS.getStart()),
+ startSpecifier, specifierLen);
+ return false;
+ }
+ }
+
+ // Check if the field with is non-zero.
+ const OptionalAmount &Amt = FS.getFieldWidth();
+ if (Amt.getHowSpecified() == OptionalAmount::Constant) {
+ if (Amt.getConstantAmount() == 0) {
+ const CharSourceRange &R = getSpecifierRange(Amt.getStart(),
+ Amt.getConstantLength());
+ EmitFormatDiagnostic(S.PDiag(diag::warn_scanf_nonzero_width),
+ getLocationOfByte(Amt.getStart()),
+ /*IsStringLocation*/true, R,
+ FixItHint::CreateRemoval(R));
+ }
+ }
+
+ if (!FS.consumesDataArgument()) {
+ // FIXME: Technically specifying a precision or field width here
+ // makes no sense. Worth issuing a warning at some point.
+ return true;
+ }
+
+ // Consume the argument.
+ unsigned argIndex = FS.getArgIndex();
+ if (argIndex < NumDataArgs) {
+ // The check to see if the argIndex is valid will come later.
+ // We set the bit here because we may exit early from this
+ // function if we encounter some other error.
+ CoveredArgs.set(argIndex);
+ }
+
+ // Check the length modifier is valid with the given conversion specifier.
+ const LengthModifier &LM = FS.getLengthModifier();
+ if (!FS.hasValidLengthModifier()) {
+ const CharSourceRange &R = getSpecifierRange(LM.getStart(), LM.getLength());
+ EmitFormatDiagnostic(S.PDiag(diag::warn_format_nonsensical_length)
+ << LM.toString() << CS.toString()
+ << getSpecifierRange(startSpecifier, specifierLen),
+ getLocationOfByte(LM.getStart()),
+ /*IsStringLocation*/true, R,
+ FixItHint::CreateRemoval(R));
+ }
+
+ if (!FS.hasStandardLengthModifier())
+ HandleNonStandardLengthModifier(LM, startSpecifier, specifierLen);
+ if (!FS.hasStandardConversionSpecifier(S.getLangOpts()))
+ HandleNonStandardConversionSpecifier(CS, startSpecifier, specifierLen);
+ if (!FS.hasStandardLengthConversionCombination())
+ HandleNonStandardConversionSpecification(LM, CS, startSpecifier,
+ specifierLen);
+
+ // The remaining checks depend on the data arguments.
+ if (HasVAListArg)
+ return true;
+
+ if (!CheckNumArgs(FS, CS, startSpecifier, specifierLen, argIndex))
+ return false;
+
+ // Check that the argument type matches the format specifier.
+ const Expr *Ex = getDataArg(argIndex);
+ const analyze_scanf::ScanfArgTypeResult &ATR = FS.getArgType(S.Context);
+ if (ATR.isValid() && !ATR.matchesType(S.Context, Ex->getType())) {
+ ScanfSpecifier fixedFS = FS;
+ bool success = fixedFS.fixType(Ex->getType(), S.getLangOpts(),
+ S.Context);
+
+ if (success) {
+ // Get the fix string from the fixed format specifier.
+ SmallString<128> buf;
+ llvm::raw_svector_ostream os(buf);
+ fixedFS.toString(os);
+
+ EmitFormatDiagnostic(
+ S.PDiag(diag::warn_printf_conversion_argument_type_mismatch)
+ << ATR.getRepresentativeTypeName(S.Context) << Ex->getType()
+ << Ex->getSourceRange(),
+ getLocationOfByte(CS.getStart()),
+ /*IsStringLocation*/true,
+ getSpecifierRange(startSpecifier, specifierLen),
+ FixItHint::CreateReplacement(
+ getSpecifierRange(startSpecifier, specifierLen),
+ os.str()));
+ } else {
+ EmitFormatDiagnostic(
+ S.PDiag(diag::warn_printf_conversion_argument_type_mismatch)
+ << ATR.getRepresentativeTypeName(S.Context) << Ex->getType()
+ << Ex->getSourceRange(),
+ getLocationOfByte(CS.getStart()),
+ /*IsStringLocation*/true,
+ getSpecifierRange(startSpecifier, specifierLen));
+ }
+ }
+
+ return true;
+}
+
+void Sema::CheckFormatString(const StringLiteral *FExpr,
+ const Expr *OrigFormatExpr,
+ Expr **Args, unsigned NumArgs,
+ bool HasVAListArg, unsigned format_idx,
+ unsigned firstDataArg, FormatStringType Type,
+ bool inFunctionCall) {
+
+ // CHECK: is the format string a wide literal?
+ if (!FExpr->isAscii()) {
+ CheckFormatHandler::EmitFormatDiagnostic(
+ *this, inFunctionCall, Args[format_idx],
+ PDiag(diag::warn_format_string_is_wide_literal), FExpr->getLocStart(),
+ /*IsStringLocation*/true, OrigFormatExpr->getSourceRange());
+ return;
+ }
+
+ // Str - The format string. NOTE: this is NOT null-terminated!
+ StringRef StrRef = FExpr->getString();
+ const char *Str = StrRef.data();
+ unsigned StrLen = StrRef.size();
+ const unsigned numDataArgs = NumArgs - firstDataArg;
+
+ // CHECK: empty format string?
+ if (StrLen == 0 && numDataArgs > 0) {
+ CheckFormatHandler::EmitFormatDiagnostic(
+ *this, inFunctionCall, Args[format_idx],
+ PDiag(diag::warn_empty_format_string), FExpr->getLocStart(),
+ /*IsStringLocation*/true, OrigFormatExpr->getSourceRange());
+ return;
+ }
+
+ if (Type == FST_Printf || Type == FST_NSString) {
+ CheckPrintfHandler H(*this, FExpr, OrigFormatExpr, firstDataArg,
+ numDataArgs, isa<ObjCStringLiteral>(OrigFormatExpr),
+ Str, HasVAListArg, Args, NumArgs, format_idx,
+ inFunctionCall);
+
+ if (!analyze_format_string::ParsePrintfString(H, Str, Str + StrLen,
+ getLangOpts()))
+ H.DoneProcessing();
+ } else if (Type == FST_Scanf) {
+ CheckScanfHandler H(*this, FExpr, OrigFormatExpr, firstDataArg,
+ numDataArgs, isa<ObjCStringLiteral>(OrigFormatExpr),
+ Str, HasVAListArg, Args, NumArgs, format_idx,
+ inFunctionCall);
+
+ if (!analyze_format_string::ParseScanfString(H, Str, Str + StrLen,
+ getLangOpts()))
+ H.DoneProcessing();
+ } // TODO: handle other formats
+}
+
+//===--- CHECK: Standard memory functions ---------------------------------===//
+
+/// \brief Determine whether the given type is a dynamic class type (e.g.,
+/// whether it has a vtable).
+static bool isDynamicClassType(QualType T) {
+ if (CXXRecordDecl *Record = T->getAsCXXRecordDecl())
+ if (CXXRecordDecl *Definition = Record->getDefinition())
+ if (Definition->isDynamicClass())
+ return true;
+
+ return false;
+}
+
+/// \brief If E is a sizeof expression, returns its argument expression,
+/// otherwise returns NULL.
+static const Expr *getSizeOfExprArg(const Expr* E) {
+ if (const UnaryExprOrTypeTraitExpr *SizeOf =
+ dyn_cast<UnaryExprOrTypeTraitExpr>(E))
+ if (SizeOf->getKind() == clang::UETT_SizeOf && !SizeOf->isArgumentType())
+ return SizeOf->getArgumentExpr()->IgnoreParenImpCasts();
+
+ return 0;
+}
+
+/// \brief If E is a sizeof expression, returns its argument type.
+static QualType getSizeOfArgType(const Expr* E) {
+ if (const UnaryExprOrTypeTraitExpr *SizeOf =
+ dyn_cast<UnaryExprOrTypeTraitExpr>(E))
+ if (SizeOf->getKind() == clang::UETT_SizeOf)
+ return SizeOf->getTypeOfArgument();
+
+ return QualType();
+}
+
+/// \brief Check for dangerous or invalid arguments to memset().
+///
+/// This issues warnings on known problematic, dangerous or unspecified
+/// arguments to the standard 'memset', 'memcpy', 'memmove', and 'memcmp'
+/// function calls.
+///
+/// \param Call The call expression to diagnose.
+void Sema::CheckMemaccessArguments(const CallExpr *Call,
+ unsigned BId,
+ IdentifierInfo *FnName) {
+ assert(BId != 0);
+
+ // It is possible to have a non-standard definition of memset. Validate
+ // we have enough arguments, and if not, abort further checking.
+ unsigned ExpectedNumArgs = (BId == Builtin::BIstrndup ? 2 : 3);
+ if (Call->getNumArgs() < ExpectedNumArgs)
+ return;
+
+ unsigned LastArg = (BId == Builtin::BImemset ||
+ BId == Builtin::BIstrndup ? 1 : 2);
+ unsigned LenArg = (BId == Builtin::BIstrndup ? 1 : 2);
+ const Expr *LenExpr = Call->getArg(LenArg)->IgnoreParenImpCasts();
+
+ // We have special checking when the length is a sizeof expression.
+ QualType SizeOfArgTy = getSizeOfArgType(LenExpr);
+ const Expr *SizeOfArg = getSizeOfExprArg(LenExpr);
+ llvm::FoldingSetNodeID SizeOfArgID;
+
+ for (unsigned ArgIdx = 0; ArgIdx != LastArg; ++ArgIdx) {
+ const Expr *Dest = Call->getArg(ArgIdx)->IgnoreParenImpCasts();
+ SourceRange ArgRange = Call->getArg(ArgIdx)->getSourceRange();
+
+ QualType DestTy = Dest->getType();
+ if (const PointerType *DestPtrTy = DestTy->getAs<PointerType>()) {
+ QualType PointeeTy = DestPtrTy->getPointeeType();
+
+ // Never warn about void type pointers. This can be used to suppress
+ // false positives.
+ if (PointeeTy->isVoidType())
+ continue;
+
+ // Catch "memset(p, 0, sizeof(p))" -- needs to be sizeof(*p). Do this by
+ // actually comparing the expressions for equality. Because computing the
+ // expression IDs can be expensive, we only do this if the diagnostic is
+ // enabled.
+ if (SizeOfArg &&
+ Diags.getDiagnosticLevel(diag::warn_sizeof_pointer_expr_memaccess,
+ SizeOfArg->getExprLoc())) {
+ // We only compute IDs for expressions if the warning is enabled, and
+ // cache the sizeof arg's ID.
+ if (SizeOfArgID == llvm::FoldingSetNodeID())
+ SizeOfArg->Profile(SizeOfArgID, Context, true);
+ llvm::FoldingSetNodeID DestID;
+ Dest->Profile(DestID, Context, true);
+ if (DestID == SizeOfArgID) {
+ // TODO: For strncpy() and friends, this could suggest sizeof(dst)
+ // over sizeof(src) as well.
+ unsigned ActionIdx = 0; // Default is to suggest dereferencing.
+ if (const UnaryOperator *UnaryOp = dyn_cast<UnaryOperator>(Dest))
+ if (UnaryOp->getOpcode() == UO_AddrOf)
+ ActionIdx = 1; // If its an address-of operator, just remove it.
+ if (Context.getTypeSize(PointeeTy) == Context.getCharWidth())
+ ActionIdx = 2; // If the pointee's size is sizeof(char),
+ // suggest an explicit length.
+ unsigned DestSrcSelect =
+ (BId == Builtin::BIstrndup ? 1 : ArgIdx);
+ DiagRuntimeBehavior(SizeOfArg->getExprLoc(), Dest,
+ PDiag(diag::warn_sizeof_pointer_expr_memaccess)
+ << FnName << DestSrcSelect << ActionIdx
+ << Dest->getSourceRange()
+ << SizeOfArg->getSourceRange());
+ break;
+ }
+ }
+
+ // Also check for cases where the sizeof argument is the exact same
+ // type as the memory argument, and where it points to a user-defined
+ // record type.
+ if (SizeOfArgTy != QualType()) {
+ if (PointeeTy->isRecordType() &&
+ Context.typesAreCompatible(SizeOfArgTy, DestTy)) {
+ DiagRuntimeBehavior(LenExpr->getExprLoc(), Dest,
+ PDiag(diag::warn_sizeof_pointer_type_memaccess)
+ << FnName << SizeOfArgTy << ArgIdx
+ << PointeeTy << Dest->getSourceRange()
+ << LenExpr->getSourceRange());
+ break;
+ }
+ }
+
+ // Always complain about dynamic classes.
+ if (isDynamicClassType(PointeeTy)) {
+
+ unsigned OperationType = 0;
+ // "overwritten" if we're warning about the destination for any call
+ // but memcmp; otherwise a verb appropriate to the call.
+ if (ArgIdx != 0 || BId == Builtin::BImemcmp) {
+ if (BId == Builtin::BImemcpy)
+ OperationType = 1;
+ else if(BId == Builtin::BImemmove)
+ OperationType = 2;
+ else if (BId == Builtin::BImemcmp)
+ OperationType = 3;
+ }
+
+ DiagRuntimeBehavior(
+ Dest->getExprLoc(), Dest,
+ PDiag(diag::warn_dyn_class_memaccess)
+ << (BId == Builtin::BImemcmp ? ArgIdx + 2 : ArgIdx)
+ << FnName << PointeeTy
+ << OperationType
+ << Call->getCallee()->getSourceRange());
+ } else if (PointeeTy.hasNonTrivialObjCLifetime() &&
+ BId != Builtin::BImemset)
+ DiagRuntimeBehavior(
+ Dest->getExprLoc(), Dest,
+ PDiag(diag::warn_arc_object_memaccess)
+ << ArgIdx << FnName << PointeeTy
+ << Call->getCallee()->getSourceRange());
+ else
+ continue;
+
+ DiagRuntimeBehavior(
+ Dest->getExprLoc(), Dest,
+ PDiag(diag::note_bad_memaccess_silence)
+ << FixItHint::CreateInsertion(ArgRange.getBegin(), "(void*)"));
+ break;
+ }
+ }
+}
+
+// A little helper routine: ignore addition and subtraction of integer literals.
+// This intentionally does not ignore all integer constant expressions because
+// we don't want to remove sizeof().
+static const Expr *ignoreLiteralAdditions(const Expr *Ex, ASTContext &Ctx) {
+ Ex = Ex->IgnoreParenCasts();
+
+ for (;;) {
+ const BinaryOperator * BO = dyn_cast<BinaryOperator>(Ex);
+ if (!BO || !BO->isAdditiveOp())
+ break;
+
+ const Expr *RHS = BO->getRHS()->IgnoreParenCasts();
+ const Expr *LHS = BO->getLHS()->IgnoreParenCasts();
+
+ if (isa<IntegerLiteral>(RHS))
+ Ex = LHS;
+ else if (isa<IntegerLiteral>(LHS))
+ Ex = RHS;
+ else
+ break;
+ }
+
+ return Ex;
+}
+
+// Warn if the user has made the 'size' argument to strlcpy or strlcat
+// be the size of the source, instead of the destination.
+void Sema::CheckStrlcpycatArguments(const CallExpr *Call,
+ IdentifierInfo *FnName) {
+
+ // Don't crash if the user has the wrong number of arguments
+ if (Call->getNumArgs() != 3)
+ return;
+
+ const Expr *SrcArg = ignoreLiteralAdditions(Call->getArg(1), Context);
+ const Expr *SizeArg = ignoreLiteralAdditions(Call->getArg(2), Context);
+ const Expr *CompareWithSrc = NULL;
+
+ // Look for 'strlcpy(dst, x, sizeof(x))'
+ if (const Expr *Ex = getSizeOfExprArg(SizeArg))
+ CompareWithSrc = Ex;
+ else {
+ // Look for 'strlcpy(dst, x, strlen(x))'
+ if (const CallExpr *SizeCall = dyn_cast<CallExpr>(SizeArg)) {
+ if (SizeCall->isBuiltinCall() == Builtin::BIstrlen
+ && SizeCall->getNumArgs() == 1)
+ CompareWithSrc = ignoreLiteralAdditions(SizeCall->getArg(0), Context);
+ }
+ }
+
+ if (!CompareWithSrc)
+ return;
+
+ // Determine if the argument to sizeof/strlen is equal to the source
+ // argument. In principle there's all kinds of things you could do
+ // here, for instance creating an == expression and evaluating it with
+ // EvaluateAsBooleanCondition, but this uses a more direct technique:
+ const DeclRefExpr *SrcArgDRE = dyn_cast<DeclRefExpr>(SrcArg);
+ if (!SrcArgDRE)
+ return;
+
+ const DeclRefExpr *CompareWithSrcDRE = dyn_cast<DeclRefExpr>(CompareWithSrc);
+ if (!CompareWithSrcDRE ||
+ SrcArgDRE->getDecl() != CompareWithSrcDRE->getDecl())
+ return;
+
+ const Expr *OriginalSizeArg = Call->getArg(2);
+ Diag(CompareWithSrcDRE->getLocStart(), diag::warn_strlcpycat_wrong_size)
+ << OriginalSizeArg->getSourceRange() << FnName;
+
+ // Output a FIXIT hint if the destination is an array (rather than a
+ // pointer to an array). This could be enhanced to handle some
+ // pointers if we know the actual size, like if DstArg is 'array+2'
+ // we could say 'sizeof(array)-2'.
+ const Expr *DstArg = Call->getArg(0)->IgnoreParenImpCasts();
+ QualType DstArgTy = DstArg->getType();
+
+ // Only handle constant-sized or VLAs, but not flexible members.
+ if (const ConstantArrayType *CAT = Context.getAsConstantArrayType(DstArgTy)) {
+ // Only issue the FIXIT for arrays of size > 1.
+ if (CAT->getSize().getSExtValue() <= 1)
+ return;
+ } else if (!DstArgTy->isVariableArrayType()) {
+ return;
+ }
+
+ SmallString<128> sizeString;
+ llvm::raw_svector_ostream OS(sizeString);
+ OS << "sizeof(";
+ DstArg->printPretty(OS, Context, 0, getPrintingPolicy());
+ OS << ")";
+
+ Diag(OriginalSizeArg->getLocStart(), diag::note_strlcpycat_wrong_size)
+ << FixItHint::CreateReplacement(OriginalSizeArg->getSourceRange(),
+ OS.str());
+}
+
+/// Check if two expressions refer to the same declaration.
+static bool referToTheSameDecl(const Expr *E1, const Expr *E2) {
+ if (const DeclRefExpr *D1 = dyn_cast_or_null<DeclRefExpr>(E1))
+ if (const DeclRefExpr *D2 = dyn_cast_or_null<DeclRefExpr>(E2))
+ return D1->getDecl() == D2->getDecl();
+ return false;
+}
+
+static const Expr *getStrlenExprArg(const Expr *E) {
+ if (const CallExpr *CE = dyn_cast<CallExpr>(E)) {
+ const FunctionDecl *FD = CE->getDirectCallee();
+ if (!FD || FD->getMemoryFunctionKind() != Builtin::BIstrlen)
+ return 0;
+ return CE->getArg(0)->IgnoreParenCasts();
+ }
+ return 0;
+}
+
+// Warn on anti-patterns as the 'size' argument to strncat.
+// The correct size argument should look like following:
+// strncat(dst, src, sizeof(dst) - strlen(dest) - 1);
+void Sema::CheckStrncatArguments(const CallExpr *CE,
+ IdentifierInfo *FnName) {
+ // Don't crash if the user has the wrong number of arguments.
+ if (CE->getNumArgs() < 3)
+ return;
+ const Expr *DstArg = CE->getArg(0)->IgnoreParenCasts();
+ const Expr *SrcArg = CE->getArg(1)->IgnoreParenCasts();
+ const Expr *LenArg = CE->getArg(2)->IgnoreParenCasts();
+
+ // Identify common expressions, which are wrongly used as the size argument
+ // to strncat and may lead to buffer overflows.
+ unsigned PatternType = 0;
+ if (const Expr *SizeOfArg = getSizeOfExprArg(LenArg)) {
+ // - sizeof(dst)
+ if (referToTheSameDecl(SizeOfArg, DstArg))
+ PatternType = 1;
+ // - sizeof(src)
+ else if (referToTheSameDecl(SizeOfArg, SrcArg))
+ PatternType = 2;
+ } else if (const BinaryOperator *BE = dyn_cast<BinaryOperator>(LenArg)) {
+ if (BE->getOpcode() == BO_Sub) {
+ const Expr *L = BE->getLHS()->IgnoreParenCasts();
+ const Expr *R = BE->getRHS()->IgnoreParenCasts();
+ // - sizeof(dst) - strlen(dst)
+ if (referToTheSameDecl(DstArg, getSizeOfExprArg(L)) &&
+ referToTheSameDecl(DstArg, getStrlenExprArg(R)))
+ PatternType = 1;
+ // - sizeof(src) - (anything)
+ else if (referToTheSameDecl(SrcArg, getSizeOfExprArg(L)))
+ PatternType = 2;
+ }
+ }
+
+ if (PatternType == 0)
+ return;
+
+ // Generate the diagnostic.
+ SourceLocation SL = LenArg->getLocStart();
+ SourceRange SR = LenArg->getSourceRange();
+ SourceManager &SM = PP.getSourceManager();
+
+ // If the function is defined as a builtin macro, do not show macro expansion.
+ if (SM.isMacroArgExpansion(SL)) {
+ SL = SM.getSpellingLoc(SL);
+ SR = SourceRange(SM.getSpellingLoc(SR.getBegin()),
+ SM.getSpellingLoc(SR.getEnd()));
+ }
+
+ if (PatternType == 1)
+ Diag(SL, diag::warn_strncat_large_size) << SR;
+ else
+ Diag(SL, diag::warn_strncat_src_size) << SR;
+
+ // Output a FIXIT hint if the destination is an array (rather than a
+ // pointer to an array). This could be enhanced to handle some
+ // pointers if we know the actual size, like if DstArg is 'array+2'
+ // we could say 'sizeof(array)-2'.
+ QualType DstArgTy = DstArg->getType();
+
+ // Only handle constant-sized or VLAs, but not flexible members.
+ if (const ConstantArrayType *CAT = Context.getAsConstantArrayType(DstArgTy)) {
+ // Only issue the FIXIT for arrays of size > 1.
+ if (CAT->getSize().getSExtValue() <= 1)
+ return;
+ } else if (!DstArgTy->isVariableArrayType()) {
+ return;
+ }
+
+ SmallString<128> sizeString;
+ llvm::raw_svector_ostream OS(sizeString);
+ OS << "sizeof(";
+ DstArg->printPretty(OS, Context, 0, getPrintingPolicy());
+ OS << ") - ";
+ OS << "strlen(";
+ DstArg->printPretty(OS, Context, 0, getPrintingPolicy());
+ OS << ") - 1";
+
+ Diag(SL, diag::note_strncat_wrong_size)
+ << FixItHint::CreateReplacement(SR, OS.str());
+}
+
+//===--- CHECK: Return Address of Stack Variable --------------------------===//
+
+static Expr *EvalVal(Expr *E, SmallVectorImpl<DeclRefExpr *> &refVars);
+static Expr *EvalAddr(Expr* E, SmallVectorImpl<DeclRefExpr *> &refVars);
+
+/// CheckReturnStackAddr - Check if a return statement returns the address
+/// of a stack variable.
+void
+Sema::CheckReturnStackAddr(Expr *RetValExp, QualType lhsType,
+ SourceLocation ReturnLoc) {
+
+ Expr *stackE = 0;
+ SmallVector<DeclRefExpr *, 8> refVars;
+
+ // Perform checking for returned stack addresses, local blocks,
+ // label addresses or references to temporaries.
+ if (lhsType->isPointerType() ||
+ (!getLangOpts().ObjCAutoRefCount && lhsType->isBlockPointerType())) {
+ stackE = EvalAddr(RetValExp, refVars);
+ } else if (lhsType->isReferenceType()) {
+ stackE = EvalVal(RetValExp, refVars);
+ }
+
+ if (stackE == 0)
+ return; // Nothing suspicious was found.
+
+ SourceLocation diagLoc;
+ SourceRange diagRange;
+ if (refVars.empty()) {
+ diagLoc = stackE->getLocStart();
+ diagRange = stackE->getSourceRange();
+ } else {
+ // We followed through a reference variable. 'stackE' contains the
+ // problematic expression but we will warn at the return statement pointing
+ // at the reference variable. We will later display the "trail" of
+ // reference variables using notes.
+ diagLoc = refVars[0]->getLocStart();
+ diagRange = refVars[0]->getSourceRange();
+ }
+
+ if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(stackE)) { //address of local var.
+ Diag(diagLoc, lhsType->isReferenceType() ? diag::warn_ret_stack_ref
+ : diag::warn_ret_stack_addr)
+ << DR->getDecl()->getDeclName() << diagRange;
+ } else if (isa<BlockExpr>(stackE)) { // local block.
+ Diag(diagLoc, diag::err_ret_local_block) << diagRange;
+ } else if (isa<AddrLabelExpr>(stackE)) { // address of label.
+ Diag(diagLoc, diag::warn_ret_addr_label) << diagRange;
+ } else { // local temporary.
+ Diag(diagLoc, lhsType->isReferenceType() ? diag::warn_ret_local_temp_ref
+ : diag::warn_ret_local_temp_addr)
+ << diagRange;
+ }
+
+ // Display the "trail" of reference variables that we followed until we
+ // found the problematic expression using notes.
+ for (unsigned i = 0, e = refVars.size(); i != e; ++i) {
+ VarDecl *VD = cast<VarDecl>(refVars[i]->getDecl());
+ // If this var binds to another reference var, show the range of the next
+ // var, otherwise the var binds to the problematic expression, in which case
+ // show the range of the expression.
+ SourceRange range = (i < e-1) ? refVars[i+1]->getSourceRange()
+ : stackE->getSourceRange();
+ Diag(VD->getLocation(), diag::note_ref_var_local_bind)
+ << VD->getDeclName() << range;
+ }
+}
+
+/// EvalAddr - EvalAddr and EvalVal are mutually recursive functions that
+/// check if the expression in a return statement evaluates to an address
+/// to a location on the stack, a local block, an address of a label, or a
+/// reference to local temporary. The recursion is used to traverse the
+/// AST of the return expression, with recursion backtracking when we
+/// encounter a subexpression that (1) clearly does not lead to one of the
+/// above problematic expressions (2) is something we cannot determine leads to
+/// a problematic expression based on such local checking.
+///
+/// Both EvalAddr and EvalVal follow through reference variables to evaluate
+/// the expression that they point to. Such variables are added to the
+/// 'refVars' vector so that we know what the reference variable "trail" was.
+///
+/// EvalAddr processes expressions that are pointers that are used as
+/// references (and not L-values). EvalVal handles all other values.
+/// At the base case of the recursion is a check for the above problematic
+/// expressions.
+///
+/// This implementation handles:
+///
+/// * pointer-to-pointer casts
+/// * implicit conversions from array references to pointers
+/// * taking the address of fields
+/// * arbitrary interplay between "&" and "*" operators
+/// * pointer arithmetic from an address of a stack variable
+/// * taking the address of an array element where the array is on the stack
+static Expr *EvalAddr(Expr *E, SmallVectorImpl<DeclRefExpr *> &refVars) {
+ if (E->isTypeDependent())
+ return NULL;
+
+ // We should only be called for evaluating pointer expressions.
+ assert((E->getType()->isAnyPointerType() ||
+ E->getType()->isBlockPointerType() ||
+ E->getType()->isObjCQualifiedIdType()) &&
+ "EvalAddr only works on pointers");
+
+ E = E->IgnoreParens();
+
+ // Our "symbolic interpreter" is just a dispatch off the currently
+ // viewed AST node. We then recursively traverse the AST by calling
+ // EvalAddr and EvalVal appropriately.
+ switch (E->getStmtClass()) {
+ case Stmt::DeclRefExprClass: {
+ DeclRefExpr *DR = cast<DeclRefExpr>(E);
+
+ if (VarDecl *V = dyn_cast<VarDecl>(DR->getDecl()))
+ // If this is a reference variable, follow through to the expression that
+ // it points to.
+ if (V->hasLocalStorage() &&
+ V->getType()->isReferenceType() && V->hasInit()) {
+ // Add the reference variable to the "trail".
+ refVars.push_back(DR);
+ return EvalAddr(V->getInit(), refVars);
+ }
+
+ return NULL;
+ }
+
+ case Stmt::UnaryOperatorClass: {
+ // The only unary operator that make sense to handle here
+ // is AddrOf. All others don't make sense as pointers.
+ UnaryOperator *U = cast<UnaryOperator>(E);
+
+ if (U->getOpcode() == UO_AddrOf)
+ return EvalVal(U->getSubExpr(), refVars);
+ else
+ return NULL;
+ }
+
+ case Stmt::BinaryOperatorClass: {
+ // Handle pointer arithmetic. All other binary operators are not valid
+ // in this context.
+ BinaryOperator *B = cast<BinaryOperator>(E);
+ BinaryOperatorKind op = B->getOpcode();
+
+ if (op != BO_Add && op != BO_Sub)
+ return NULL;
+
+ Expr *Base = B->getLHS();
+
+ // Determine which argument is the real pointer base. It could be
+ // the RHS argument instead of the LHS.
+ if (!Base->getType()->isPointerType()) Base = B->getRHS();
+
+ assert (Base->getType()->isPointerType());
+ return EvalAddr(Base, refVars);
+ }
+
+ // For conditional operators we need to see if either the LHS or RHS are
+ // valid DeclRefExpr*s. If one of them is valid, we return it.
+ case Stmt::ConditionalOperatorClass: {
+ ConditionalOperator *C = cast<ConditionalOperator>(E);
+
+ // Handle the GNU extension for missing LHS.
+ if (Expr *lhsExpr = C->getLHS()) {
+ // In C++, we can have a throw-expression, which has 'void' type.
+ if (!lhsExpr->getType()->isVoidType())
+ if (Expr* LHS = EvalAddr(lhsExpr, refVars))
+ return LHS;
+ }
+
+ // In C++, we can have a throw-expression, which has 'void' type.
+ if (C->getRHS()->getType()->isVoidType())
+ return NULL;
+
+ return EvalAddr(C->getRHS(), refVars);
+ }
+
+ case Stmt::BlockExprClass:
+ if (cast<BlockExpr>(E)->getBlockDecl()->hasCaptures())
+ return E; // local block.
+ return NULL;
+
+ case Stmt::AddrLabelExprClass:
+ return E; // address of label.
+
+ case Stmt::ExprWithCleanupsClass:
+ return EvalAddr(cast<ExprWithCleanups>(E)->getSubExpr(), refVars);
+
+ // For casts, we need to handle conversions from arrays to
+ // pointer values, and pointer-to-pointer conversions.
+ case Stmt::ImplicitCastExprClass:
+ case Stmt::CStyleCastExprClass:
+ case Stmt::CXXFunctionalCastExprClass:
+ case Stmt::ObjCBridgedCastExprClass:
+ case Stmt::CXXStaticCastExprClass:
+ case Stmt::CXXDynamicCastExprClass:
+ case Stmt::CXXConstCastExprClass:
+ case Stmt::CXXReinterpretCastExprClass: {
+ Expr* SubExpr = cast<CastExpr>(E)->getSubExpr();
+ switch (cast<CastExpr>(E)->getCastKind()) {
+ case CK_BitCast:
+ case CK_LValueToRValue:
+ case CK_NoOp:
+ case CK_BaseToDerived:
+ case CK_DerivedToBase:
+ case CK_UncheckedDerivedToBase:
+ case CK_Dynamic:
+ case CK_CPointerToObjCPointerCast:
+ case CK_BlockPointerToObjCPointerCast:
+ case CK_AnyPointerToBlockPointerCast:
+ return EvalAddr(SubExpr, refVars);
+
+ case CK_ArrayToPointerDecay:
+ return EvalVal(SubExpr, refVars);
+
+ default:
+ return 0;
+ }
+ }
+
+ case Stmt::MaterializeTemporaryExprClass:
+ if (Expr *Result = EvalAddr(
+ cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr(),
+ refVars))
+ return Result;
+
+ return E;
+
+ // Everything else: we simply don't reason about them.
+ default:
+ return NULL;
+ }
+}
+
+
+/// EvalVal - This function is complements EvalAddr in the mutual recursion.
+/// See the comments for EvalAddr for more details.
+static Expr *EvalVal(Expr *E, SmallVectorImpl<DeclRefExpr *> &refVars) {
+do {
+ // We should only be called for evaluating non-pointer expressions, or
+ // expressions with a pointer type that are not used as references but instead
+ // are l-values (e.g., DeclRefExpr with a pointer type).
+
+ // Our "symbolic interpreter" is just a dispatch off the currently
+ // viewed AST node. We then recursively traverse the AST by calling
+ // EvalAddr and EvalVal appropriately.
+
+ E = E->IgnoreParens();
+ switch (E->getStmtClass()) {
+ case Stmt::ImplicitCastExprClass: {
+ ImplicitCastExpr *IE = cast<ImplicitCastExpr>(E);
+ if (IE->getValueKind() == VK_LValue) {
+ E = IE->getSubExpr();
+ continue;
+ }
+ return NULL;
+ }
+
+ case Stmt::ExprWithCleanupsClass:
+ return EvalVal(cast<ExprWithCleanups>(E)->getSubExpr(), refVars);
+
+ case Stmt::DeclRefExprClass: {
+ // When we hit a DeclRefExpr we are looking at code that refers to a
+ // variable's name. If it's not a reference variable we check if it has
+ // local storage within the function, and if so, return the expression.
+ DeclRefExpr *DR = cast<DeclRefExpr>(E);
+
+ if (VarDecl *V = dyn_cast<VarDecl>(DR->getDecl()))
+ if (V->hasLocalStorage()) {
+ if (!V->getType()->isReferenceType())
+ return DR;
+
+ // Reference variable, follow through to the expression that
+ // it points to.
+ if (V->hasInit()) {
+ // Add the reference variable to the "trail".
+ refVars.push_back(DR);
+ return EvalVal(V->getInit(), refVars);
+ }
+ }
+
+ return NULL;
+ }
+
+ case Stmt::UnaryOperatorClass: {
+ // The only unary operator that make sense to handle here
+ // is Deref. All others don't resolve to a "name." This includes
+ // handling all sorts of rvalues passed to a unary operator.
+ UnaryOperator *U = cast<UnaryOperator>(E);
+
+ if (U->getOpcode() == UO_Deref)
+ return EvalAddr(U->getSubExpr(), refVars);
+
+ return NULL;
+ }
+
+ case Stmt::ArraySubscriptExprClass: {
+ // Array subscripts are potential references to data on the stack. We
+ // retrieve the DeclRefExpr* for the array variable if it indeed
+ // has local storage.
+ return EvalAddr(cast<ArraySubscriptExpr>(E)->getBase(), refVars);
+ }
+
+ case Stmt::ConditionalOperatorClass: {
+ // For conditional operators we need to see if either the LHS or RHS are
+ // non-NULL Expr's. If one is non-NULL, we return it.
+ ConditionalOperator *C = cast<ConditionalOperator>(E);
+
+ // Handle the GNU extension for missing LHS.
+ if (Expr *lhsExpr = C->getLHS())
+ if (Expr *LHS = EvalVal(lhsExpr, refVars))
+ return LHS;
+
+ return EvalVal(C->getRHS(), refVars);
+ }
+
+ // Accesses to members are potential references to data on the stack.
+ case Stmt::MemberExprClass: {
+ MemberExpr *M = cast<MemberExpr>(E);
+
+ // Check for indirect access. We only want direct field accesses.
+ if (M->isArrow())
+ return NULL;
+
+ // Check whether the member type is itself a reference, in which case
+ // we're not going to refer to the member, but to what the member refers to.
+ if (M->getMemberDecl()->getType()->isReferenceType())
+ return NULL;
+
+ return EvalVal(M->getBase(), refVars);
+ }
+
+ case Stmt::MaterializeTemporaryExprClass:
+ if (Expr *Result = EvalVal(
+ cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr(),
+ refVars))
+ return Result;
+
+ return E;
+
+ default:
+ // Check that we don't return or take the address of a reference to a
+ // temporary. This is only useful in C++.
+ if (!E->isTypeDependent() && E->isRValue())
+ return E;
+
+ // Everything else: we simply don't reason about them.
+ return NULL;
+ }
+} while (true);
+}
+
+//===--- CHECK: Floating-Point comparisons (-Wfloat-equal) ---------------===//
+
+/// Check for comparisons of floating point operands using != and ==.
+/// Issue a warning if these are no self-comparisons, as they are not likely
+/// to do what the programmer intended.
+void Sema::CheckFloatComparison(SourceLocation Loc, Expr* LHS, Expr *RHS) {
+ bool EmitWarning = true;
+
+ Expr* LeftExprSansParen = LHS->IgnoreParenImpCasts();
+ Expr* RightExprSansParen = RHS->IgnoreParenImpCasts();
+
+ // Special case: check for x == x (which is OK).
+ // Do not emit warnings for such cases.
+ if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LeftExprSansParen))
+ if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RightExprSansParen))
+ if (DRL->getDecl() == DRR->getDecl())
+ EmitWarning = false;
+
+
+ // Special case: check for comparisons against literals that can be exactly
+ // represented by APFloat. In such cases, do not emit a warning. This
+ // is a heuristic: often comparison against such literals are used to
+ // detect if a value in a variable has not changed. This clearly can
+ // lead to false negatives.
+ if (EmitWarning) {
+ if (FloatingLiteral* FLL = dyn_cast<FloatingLiteral>(LeftExprSansParen)) {
+ if (FLL->isExact())
+ EmitWarning = false;
+ } else
+ if (FloatingLiteral* FLR = dyn_cast<FloatingLiteral>(RightExprSansParen)){
+ if (FLR->isExact())
+ EmitWarning = false;
+ }
+ }
+
+ // Check for comparisons with builtin types.
+ if (EmitWarning)
+ if (CallExpr* CL = dyn_cast<CallExpr>(LeftExprSansParen))
+ if (CL->isBuiltinCall())
+ EmitWarning = false;
+
+ if (EmitWarning)
+ if (CallExpr* CR = dyn_cast<CallExpr>(RightExprSansParen))
+ if (CR->isBuiltinCall())
+ EmitWarning = false;
+
+ // Emit the diagnostic.
+ if (EmitWarning)
+ Diag(Loc, diag::warn_floatingpoint_eq)
+ << LHS->getSourceRange() << RHS->getSourceRange();
+}
+
+//===--- CHECK: Integer mixed-sign comparisons (-Wsign-compare) --------===//
+//===--- CHECK: Lossy implicit conversions (-Wconversion) --------------===//
+
+namespace {
+
+/// Structure recording the 'active' range of an integer-valued
+/// expression.
+struct IntRange {
+ /// The number of bits active in the int.
+ unsigned Width;
+
+ /// True if the int is known not to have negative values.
+ bool NonNegative;
+
+ IntRange(unsigned Width, bool NonNegative)
+ : Width(Width), NonNegative(NonNegative)
+ {}
+
+ /// Returns the range of the bool type.
+ static IntRange forBoolType() {
+ return IntRange(1, true);
+ }
+
+ /// Returns the range of an opaque value of the given integral type.
+ static IntRange forValueOfType(ASTContext &C, QualType T) {
+ return forValueOfCanonicalType(C,
+ T->getCanonicalTypeInternal().getTypePtr());
+ }
+
+ /// Returns the range of an opaque value of a canonical integral type.
+ static IntRange forValueOfCanonicalType(ASTContext &C, const Type *T) {
+ assert(T->isCanonicalUnqualified());
+
+ if (const VectorType *VT = dyn_cast<VectorType>(T))
+ T = VT->getElementType().getTypePtr();
+ if (const ComplexType *CT = dyn_cast<ComplexType>(T))
+ T = CT->getElementType().getTypePtr();
+
+ // For enum types, use the known bit width of the enumerators.
+ if (const EnumType *ET = dyn_cast<EnumType>(T)) {
+ EnumDecl *Enum = ET->getDecl();
+ if (!Enum->isCompleteDefinition())
+ return IntRange(C.getIntWidth(QualType(T, 0)), false);
+
+ unsigned NumPositive = Enum->getNumPositiveBits();
+ unsigned NumNegative = Enum->getNumNegativeBits();
+
+ return IntRange(std::max(NumPositive, NumNegative), NumNegative == 0);
+ }
+
+ const BuiltinType *BT = cast<BuiltinType>(T);
+ assert(BT->isInteger());
+
+ return IntRange(C.getIntWidth(QualType(T, 0)), BT->isUnsignedInteger());
+ }
+
+ /// Returns the "target" range of a canonical integral type, i.e.
+ /// the range of values expressible in the type.
+ ///
+ /// This matches forValueOfCanonicalType except that enums have the
+ /// full range of their type, not the range of their enumerators.
+ static IntRange forTargetOfCanonicalType(ASTContext &C, const Type *T) {
+ assert(T->isCanonicalUnqualified());
+
+ if (const VectorType *VT = dyn_cast<VectorType>(T))
+ T = VT->getElementType().getTypePtr();
+ if (const ComplexType *CT = dyn_cast<ComplexType>(T))
+ T = CT->getElementType().getTypePtr();
+ if (const EnumType *ET = dyn_cast<EnumType>(T))
+ T = C.getCanonicalType(ET->getDecl()->getIntegerType()).getTypePtr();
+
+ const BuiltinType *BT = cast<BuiltinType>(T);
+ assert(BT->isInteger());
+
+ return IntRange(C.getIntWidth(QualType(T, 0)), BT->isUnsignedInteger());
+ }
+
+ /// Returns the supremum of two ranges: i.e. their conservative merge.
+ static IntRange join(IntRange L, IntRange R) {
+ return IntRange(std::max(L.Width, R.Width),
+ L.NonNegative && R.NonNegative);
+ }
+
+ /// Returns the infinum of two ranges: i.e. their aggressive merge.
+ static IntRange meet(IntRange L, IntRange R) {
+ return IntRange(std::min(L.Width, R.Width),
+ L.NonNegative || R.NonNegative);
+ }
+};
+
+static IntRange GetValueRange(ASTContext &C, llvm::APSInt &value,
+ unsigned MaxWidth) {
+ if (value.isSigned() && value.isNegative())
+ return IntRange(value.getMinSignedBits(), false);
+
+ if (value.getBitWidth() > MaxWidth)
+ value = value.trunc(MaxWidth);
+
+ // isNonNegative() just checks the sign bit without considering
+ // signedness.
+ return IntRange(value.getActiveBits(), true);
+}
+
+static IntRange GetValueRange(ASTContext &C, APValue &result, QualType Ty,
+ unsigned MaxWidth) {
+ if (result.isInt())
+ return GetValueRange(C, result.getInt(), MaxWidth);
+
+ if (result.isVector()) {
+ IntRange R = GetValueRange(C, result.getVectorElt(0), Ty, MaxWidth);
+ for (unsigned i = 1, e = result.getVectorLength(); i != e; ++i) {
+ IntRange El = GetValueRange(C, result.getVectorElt(i), Ty, MaxWidth);
+ R = IntRange::join(R, El);
+ }
+ return R;
+ }
+
+ if (result.isComplexInt()) {
+ IntRange R = GetValueRange(C, result.getComplexIntReal(), MaxWidth);
+ IntRange I = GetValueRange(C, result.getComplexIntImag(), MaxWidth);
+ return IntRange::join(R, I);
+ }
+
+ // This can happen with lossless casts to intptr_t of "based" lvalues.
+ // Assume it might use arbitrary bits.
+ // FIXME: The only reason we need to pass the type in here is to get
+ // the sign right on this one case. It would be nice if APValue
+ // preserved this.
+ assert(result.isLValue() || result.isAddrLabelDiff());
+ return IntRange(MaxWidth, Ty->isUnsignedIntegerOrEnumerationType());
+}
+
+/// Pseudo-evaluate the given integer expression, estimating the
+/// range of values it might take.
+///
+/// \param MaxWidth - the width to which the value will be truncated
+static IntRange GetExprRange(ASTContext &C, Expr *E, unsigned MaxWidth) {
+ E = E->IgnoreParens();
+
+ // Try a full evaluation first.
+ Expr::EvalResult result;
+ if (E->EvaluateAsRValue(result, C))
+ return GetValueRange(C, result.Val, E->getType(), MaxWidth);
+
+ // I think we only want to look through implicit casts here; if the
+ // user has an explicit widening cast, we should treat the value as
+ // being of the new, wider type.
+ if (ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E)) {
+ if (CE->getCastKind() == CK_NoOp || CE->getCastKind() == CK_LValueToRValue)
+ return GetExprRange(C, CE->getSubExpr(), MaxWidth);
+
+ IntRange OutputTypeRange = IntRange::forValueOfType(C, CE->getType());
+
+ bool isIntegerCast = (CE->getCastKind() == CK_IntegralCast);
+
+ // Assume that non-integer casts can span the full range of the type.
+ if (!isIntegerCast)
+ return OutputTypeRange;
+
+ IntRange SubRange
+ = GetExprRange(C, CE->getSubExpr(),
+ std::min(MaxWidth, OutputTypeRange.Width));
+
+ // Bail out if the subexpr's range is as wide as the cast type.
+ if (SubRange.Width >= OutputTypeRange.Width)
+ return OutputTypeRange;
+
+ // Otherwise, we take the smaller width, and we're non-negative if
+ // either the output type or the subexpr is.
+ return IntRange(SubRange.Width,
+ SubRange.NonNegative || OutputTypeRange.NonNegative);
+ }
+
+ if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
+ // If we can fold the condition, just take that operand.
+ bool CondResult;
+ if (CO->getCond()->EvaluateAsBooleanCondition(CondResult, C))
+ return GetExprRange(C, CondResult ? CO->getTrueExpr()
+ : CO->getFalseExpr(),
+ MaxWidth);
+
+ // Otherwise, conservatively merge.
+ IntRange L = GetExprRange(C, CO->getTrueExpr(), MaxWidth);
+ IntRange R = GetExprRange(C, CO->getFalseExpr(), MaxWidth);
+ return IntRange::join(L, R);
+ }
+
+ if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
+ switch (BO->getOpcode()) {
+
+ // Boolean-valued operations are single-bit and positive.
+ case BO_LAnd:
+ case BO_LOr:
+ case BO_LT:
+ case BO_GT:
+ case BO_LE:
+ case BO_GE:
+ case BO_EQ:
+ case BO_NE:
+ return IntRange::forBoolType();
+
+ // The type of the assignments is the type of the LHS, so the RHS
+ // is not necessarily the same type.
+ case BO_MulAssign:
+ case BO_DivAssign:
+ case BO_RemAssign:
+ case BO_AddAssign:
+ case BO_SubAssign:
+ case BO_XorAssign:
+ case BO_OrAssign:
+ // TODO: bitfields?
+ return IntRange::forValueOfType(C, E->getType());
+
+ // Simple assignments just pass through the RHS, which will have
+ // been coerced to the LHS type.
+ case BO_Assign:
+ // TODO: bitfields?
+ return GetExprRange(C, BO->getRHS(), MaxWidth);
+
+ // Operations with opaque sources are black-listed.
+ case BO_PtrMemD:
+ case BO_PtrMemI:
+ return IntRange::forValueOfType(C, E->getType());
+
+ // Bitwise-and uses the *infinum* of the two source ranges.
+ case BO_And:
+ case BO_AndAssign:
+ return IntRange::meet(GetExprRange(C, BO->getLHS(), MaxWidth),
+ GetExprRange(C, BO->getRHS(), MaxWidth));
+
+ // Left shift gets black-listed based on a judgement call.
+ case BO_Shl:
+ // ...except that we want to treat '1 << (blah)' as logically
+ // positive. It's an important idiom.
+ if (IntegerLiteral *I
+ = dyn_cast<IntegerLiteral>(BO->getLHS()->IgnoreParenCasts())) {
+ if (I->getValue() == 1) {
+ IntRange R = IntRange::forValueOfType(C, E->getType());
+ return IntRange(R.Width, /*NonNegative*/ true);
+ }
+ }
+ // fallthrough
+
+ case BO_ShlAssign:
+ return IntRange::forValueOfType(C, E->getType());
+
+ // Right shift by a constant can narrow its left argument.
+ case BO_Shr:
+ case BO_ShrAssign: {
+ IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth);
+
+ // If the shift amount is a positive constant, drop the width by
+ // that much.
+ llvm::APSInt shift;
+ if (BO->getRHS()->isIntegerConstantExpr(shift, C) &&
+ shift.isNonNegative()) {
+ unsigned zext = shift.getZExtValue();
+ if (zext >= L.Width)
+ L.Width = (L.NonNegative ? 0 : 1);
+ else
+ L.Width -= zext;
+ }
+
+ return L;
+ }
+
+ // Comma acts as its right operand.
+ case BO_Comma:
+ return GetExprRange(C, BO->getRHS(), MaxWidth);
+
+ // Black-list pointer subtractions.
+ case BO_Sub:
+ if (BO->getLHS()->getType()->isPointerType())
+ return IntRange::forValueOfType(C, E->getType());
+ break;
+
+ // The width of a division result is mostly determined by the size
+ // of the LHS.
+ case BO_Div: {
+ // Don't 'pre-truncate' the operands.
+ unsigned opWidth = C.getIntWidth(E->getType());
+ IntRange L = GetExprRange(C, BO->getLHS(), opWidth);
+
+ // If the divisor is constant, use that.
+ llvm::APSInt divisor;
+ if (BO->getRHS()->isIntegerConstantExpr(divisor, C)) {
+ unsigned log2 = divisor.logBase2(); // floor(log_2(divisor))
+ if (log2 >= L.Width)
+ L.Width = (L.NonNegative ? 0 : 1);
+ else
+ L.Width = std::min(L.Width - log2, MaxWidth);
+ return L;
+ }
+
+ // Otherwise, just use the LHS's width.
+ IntRange R = GetExprRange(C, BO->getRHS(), opWidth);
+ return IntRange(L.Width, L.NonNegative && R.NonNegative);
+ }
+
+ // The result of a remainder can't be larger than the result of
+ // either side.
+ case BO_Rem: {
+ // Don't 'pre-truncate' the operands.
+ unsigned opWidth = C.getIntWidth(E->getType());
+ IntRange L = GetExprRange(C, BO->getLHS(), opWidth);
+ IntRange R = GetExprRange(C, BO->getRHS(), opWidth);
+
+ IntRange meet = IntRange::meet(L, R);
+ meet.Width = std::min(meet.Width, MaxWidth);
+ return meet;
+ }
+
+ // The default behavior is okay for these.
+ case BO_Mul:
+ case BO_Add:
+ case BO_Xor:
+ case BO_Or:
+ break;
+ }
+
+ // The default case is to treat the operation as if it were closed
+ // on the narrowest type that encompasses both operands.
+ IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth);
+ IntRange R = GetExprRange(C, BO->getRHS(), MaxWidth);
+ return IntRange::join(L, R);
+ }
+
+ if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
+ switch (UO->getOpcode()) {
+ // Boolean-valued operations are white-listed.
+ case UO_LNot:
+ return IntRange::forBoolType();
+
+ // Operations with opaque sources are black-listed.
+ case UO_Deref:
+ case UO_AddrOf: // should be impossible
+ return IntRange::forValueOfType(C, E->getType());
+
+ default:
+ return GetExprRange(C, UO->getSubExpr(), MaxWidth);
+ }
+ }
+
+ if (dyn_cast<OffsetOfExpr>(E)) {
+ IntRange::forValueOfType(C, E->getType());
+ }
+
+ if (FieldDecl *BitField = E->getBitField())
+ return IntRange(BitField->getBitWidthValue(C),
+ BitField->getType()->isUnsignedIntegerOrEnumerationType());
+
+ return IntRange::forValueOfType(C, E->getType());
+}
+
+static IntRange GetExprRange(ASTContext &C, Expr *E) {
+ return GetExprRange(C, E, C.getIntWidth(E->getType()));
+}
+
+/// Checks whether the given value, which currently has the given
+/// source semantics, has the same value when coerced through the
+/// target semantics.
+static bool IsSameFloatAfterCast(const llvm::APFloat &value,
+ const llvm::fltSemantics &Src,
+ const llvm::fltSemantics &Tgt) {
+ llvm::APFloat truncated = value;
+
+ bool ignored;
+ truncated.convert(Src, llvm::APFloat::rmNearestTiesToEven, &ignored);
+ truncated.convert(Tgt, llvm::APFloat::rmNearestTiesToEven, &ignored);
+
+ return truncated.bitwiseIsEqual(value);
+}
+
+/// Checks whether the given value, which currently has the given
+/// source semantics, has the same value when coerced through the
+/// target semantics.
+///
+/// The value might be a vector of floats (or a complex number).
+static bool IsSameFloatAfterCast(const APValue &value,
+ const llvm::fltSemantics &Src,
+ const llvm::fltSemantics &Tgt) {
+ if (value.isFloat())
+ return IsSameFloatAfterCast(value.getFloat(), Src, Tgt);
+
+ if (value.isVector()) {
+ for (unsigned i = 0, e = value.getVectorLength(); i != e; ++i)
+ if (!IsSameFloatAfterCast(value.getVectorElt(i), Src, Tgt))
+ return false;
+ return true;
+ }
+
+ assert(value.isComplexFloat());
+ return (IsSameFloatAfterCast(value.getComplexFloatReal(), Src, Tgt) &&
+ IsSameFloatAfterCast(value.getComplexFloatImag(), Src, Tgt));
+}
+
+static void AnalyzeImplicitConversions(Sema &S, Expr *E, SourceLocation CC);
+
+static bool IsZero(Sema &S, Expr *E) {
+ // Suppress cases where we are comparing against an enum constant.
+ if (const DeclRefExpr *DR =
+ dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts()))
+ if (isa<EnumConstantDecl>(DR->getDecl()))
+ return false;
+
+ // Suppress cases where the '0' value is expanded from a macro.
+ if (E->getLocStart().isMacroID())
+ return false;
+
+ llvm::APSInt Value;
+ return E->isIntegerConstantExpr(Value, S.Context) && Value == 0;
+}
+
+static bool HasEnumType(Expr *E) {
+ // Strip off implicit integral promotions.
+ while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
+ if (ICE->getCastKind() != CK_IntegralCast &&
+ ICE->getCastKind() != CK_NoOp)
+ break;
+ E = ICE->getSubExpr();
+ }
+
+ return E->getType()->isEnumeralType();
+}
+
+static void CheckTrivialUnsignedComparison(Sema &S, BinaryOperator *E) {
+ BinaryOperatorKind op = E->getOpcode();
+ if (E->isValueDependent())
+ return;
+
+ if (op == BO_LT && IsZero(S, E->getRHS())) {
+ S.Diag(E->getOperatorLoc(), diag::warn_lunsigned_always_true_comparison)
+ << "< 0" << "false" << HasEnumType(E->getLHS())
+ << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
+ } else if (op == BO_GE && IsZero(S, E->getRHS())) {
+ S.Diag(E->getOperatorLoc(), diag::warn_lunsigned_always_true_comparison)
+ << ">= 0" << "true" << HasEnumType(E->getLHS())
+ << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
+ } else if (op == BO_GT && IsZero(S, E->getLHS())) {
+ S.Diag(E->getOperatorLoc(), diag::warn_runsigned_always_true_comparison)
+ << "0 >" << "false" << HasEnumType(E->getRHS())
+ << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
+ } else if (op == BO_LE && IsZero(S, E->getLHS())) {
+ S.Diag(E->getOperatorLoc(), diag::warn_runsigned_always_true_comparison)
+ << "0 <=" << "true" << HasEnumType(E->getRHS())
+ << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
+ }
+}
+
+/// Analyze the operands of the given comparison. Implements the
+/// fallback case from AnalyzeComparison.
+static void AnalyzeImpConvsInComparison(Sema &S, BinaryOperator *E) {
+ AnalyzeImplicitConversions(S, E->getLHS(), E->getOperatorLoc());
+ AnalyzeImplicitConversions(S, E->getRHS(), E->getOperatorLoc());
+}
+
+/// \brief Implements -Wsign-compare.
+///
+/// \param E the binary operator to check for warnings
+static void AnalyzeComparison(Sema &S, BinaryOperator *E) {
+ // The type the comparison is being performed in.
+ QualType T = E->getLHS()->getType();
+ assert(S.Context.hasSameUnqualifiedType(T, E->getRHS()->getType())
+ && "comparison with mismatched types");
+
+ // We don't do anything special if this isn't an unsigned integral
+ // comparison: we're only interested in integral comparisons, and
+ // signed comparisons only happen in cases we don't care to warn about.
+ //
+ // We also don't care about value-dependent expressions or expressions
+ // whose result is a constant.
+ if (!T->hasUnsignedIntegerRepresentation()
+ || E->isValueDependent() || E->isIntegerConstantExpr(S.Context))
+ return AnalyzeImpConvsInComparison(S, E);
+
+ Expr *LHS = E->getLHS()->IgnoreParenImpCasts();
+ Expr *RHS = E->getRHS()->IgnoreParenImpCasts();
+
+ // Check to see if one of the (unmodified) operands is of different
+ // signedness.
+ Expr *signedOperand, *unsignedOperand;
+ if (LHS->getType()->hasSignedIntegerRepresentation()) {
+ assert(!RHS->getType()->hasSignedIntegerRepresentation() &&
+ "unsigned comparison between two signed integer expressions?");
+ signedOperand = LHS;
+ unsignedOperand = RHS;
+ } else if (RHS->getType()->hasSignedIntegerRepresentation()) {
+ signedOperand = RHS;
+ unsignedOperand = LHS;
+ } else {
+ CheckTrivialUnsignedComparison(S, E);
+ return AnalyzeImpConvsInComparison(S, E);
+ }
+
+ // Otherwise, calculate the effective range of the signed operand.
+ IntRange signedRange = GetExprRange(S.Context, signedOperand);
+
+ // Go ahead and analyze implicit conversions in the operands. Note
+ // that we skip the implicit conversions on both sides.
+ AnalyzeImplicitConversions(S, LHS, E->getOperatorLoc());
+ AnalyzeImplicitConversions(S, RHS, E->getOperatorLoc());
+
+ // If the signed range is non-negative, -Wsign-compare won't fire,
+ // but we should still check for comparisons which are always true
+ // or false.
+ if (signedRange.NonNegative)
+ return CheckTrivialUnsignedComparison(S, E);
+
+ // For (in)equality comparisons, if the unsigned operand is a
+ // constant which cannot collide with a overflowed signed operand,
+ // then reinterpreting the signed operand as unsigned will not
+ // change the result of the comparison.
+ if (E->isEqualityOp()) {
+ unsigned comparisonWidth = S.Context.getIntWidth(T);
+ IntRange unsignedRange = GetExprRange(S.Context, unsignedOperand);
+
+ // We should never be unable to prove that the unsigned operand is
+ // non-negative.
+ assert(unsignedRange.NonNegative && "unsigned range includes negative?");
+
+ if (unsignedRange.Width < comparisonWidth)
+ return;
+ }
+
+ S.Diag(E->getOperatorLoc(), diag::warn_mixed_sign_comparison)
+ << LHS->getType() << RHS->getType()
+ << LHS->getSourceRange() << RHS->getSourceRange();
+}
+
+/// Analyzes an attempt to assign the given value to a bitfield.
+///
+/// Returns true if there was something fishy about the attempt.
+static bool AnalyzeBitFieldAssignment(Sema &S, FieldDecl *Bitfield, Expr *Init,
+ SourceLocation InitLoc) {
+ assert(Bitfield->isBitField());
+ if (Bitfield->isInvalidDecl())
+ return false;
+
+ // White-list bool bitfields.
+ if (Bitfield->getType()->isBooleanType())
+ return false;
+
+ // Ignore value- or type-dependent expressions.
+ if (Bitfield->getBitWidth()->isValueDependent() ||
+ Bitfield->getBitWidth()->isTypeDependent() ||
+ Init->isValueDependent() ||
+ Init->isTypeDependent())
+ return false;
+
+ Expr *OriginalInit = Init->IgnoreParenImpCasts();
+
+ llvm::APSInt Value;
+ if (!OriginalInit->EvaluateAsInt(Value, S.Context, Expr::SE_AllowSideEffects))
+ return false;
+
+ unsigned OriginalWidth = Value.getBitWidth();
+ unsigned FieldWidth = Bitfield->getBitWidthValue(S.Context);
+
+ if (OriginalWidth <= FieldWidth)
+ return false;
+
+ // Compute the value which the bitfield will contain.
+ llvm::APSInt TruncatedValue = Value.trunc(FieldWidth);
+ TruncatedValue.setIsSigned(Bitfield->getType()->isSignedIntegerType());
+
+ // Check whether the stored value is equal to the original value.
+ TruncatedValue = TruncatedValue.extend(OriginalWidth);
+ if (Value == TruncatedValue)
+ return false;
+
+ // Special-case bitfields of width 1: booleans are naturally 0/1, and
+ // therefore don't strictly fit into a signed bitfield of width 1.
+ if (FieldWidth == 1 && Value == 1)
+ return false;
+
+ std::string PrettyValue = Value.toString(10);
+ std::string PrettyTrunc = TruncatedValue.toString(10);
+
+ S.Diag(InitLoc, diag::warn_impcast_bitfield_precision_constant)
+ << PrettyValue << PrettyTrunc << OriginalInit->getType()
+ << Init->getSourceRange();
+
+ return true;
+}
+
+/// Analyze the given simple or compound assignment for warning-worthy
+/// operations.
+static void AnalyzeAssignment(Sema &S, BinaryOperator *E) {
+ // Just recurse on the LHS.
+ AnalyzeImplicitConversions(S, E->getLHS(), E->getOperatorLoc());
+
+ // We want to recurse on the RHS as normal unless we're assigning to
+ // a bitfield.
+ if (FieldDecl *Bitfield = E->getLHS()->getBitField()) {
+ if (AnalyzeBitFieldAssignment(S, Bitfield, E->getRHS(),
+ E->getOperatorLoc())) {
+ // Recurse, ignoring any implicit conversions on the RHS.
+ return AnalyzeImplicitConversions(S, E->getRHS()->IgnoreParenImpCasts(),
+ E->getOperatorLoc());
+ }
+ }
+
+ AnalyzeImplicitConversions(S, E->getRHS(), E->getOperatorLoc());
+}
+
+/// Diagnose an implicit cast; purely a helper for CheckImplicitConversion.
+static void DiagnoseImpCast(Sema &S, Expr *E, QualType SourceType, QualType T,
+ SourceLocation CContext, unsigned diag,
+ bool pruneControlFlow = false) {
+ if (pruneControlFlow) {
+ S.DiagRuntimeBehavior(E->getExprLoc(), E,
+ S.PDiag(diag)
+ << SourceType << T << E->getSourceRange()
+ << SourceRange(CContext));
+ return;
+ }
+ S.Diag(E->getExprLoc(), diag)
+ << SourceType << T << E->getSourceRange() << SourceRange(CContext);
+}
+
+/// Diagnose an implicit cast; purely a helper for CheckImplicitConversion.
+static void DiagnoseImpCast(Sema &S, Expr *E, QualType T,
+ SourceLocation CContext, unsigned diag,
+ bool pruneControlFlow = false) {
+ DiagnoseImpCast(S, E, E->getType(), T, CContext, diag, pruneControlFlow);
+}
+
+/// Diagnose an implicit cast from a literal expression. Does not warn when the
+/// cast wouldn't lose information.
+void DiagnoseFloatingLiteralImpCast(Sema &S, FloatingLiteral *FL, QualType T,
+ SourceLocation CContext) {
+ // Try to convert the literal exactly to an integer. If we can, don't warn.
+ bool isExact = false;
+ const llvm::APFloat &Value = FL->getValue();
+ llvm::APSInt IntegerValue(S.Context.getIntWidth(T),
+ T->hasUnsignedIntegerRepresentation());
+ if (Value.convertToInteger(IntegerValue,
+ llvm::APFloat::rmTowardZero, &isExact)
+ == llvm::APFloat::opOK && isExact)
+ return;
+
+ S.Diag(FL->getExprLoc(), diag::warn_impcast_literal_float_to_integer)
+ << FL->getType() << T << FL->getSourceRange() << SourceRange(CContext);
+}
+
+std::string PrettyPrintInRange(const llvm::APSInt &Value, IntRange Range) {
+ if (!Range.Width) return "0";
+
+ llvm::APSInt ValueInRange = Value;
+ ValueInRange.setIsSigned(!Range.NonNegative);
+ ValueInRange = ValueInRange.trunc(Range.Width);
+ return ValueInRange.toString(10);
+}
+
+void CheckImplicitConversion(Sema &S, Expr *E, QualType T,
+ SourceLocation CC, bool *ICContext = 0) {
+ if (E->isTypeDependent() || E->isValueDependent()) return;
+
+ const Type *Source = S.Context.getCanonicalType(E->getType()).getTypePtr();
+ const Type *Target = S.Context.getCanonicalType(T).getTypePtr();
+ if (Source == Target) return;
+ if (Target->isDependentType()) return;
+
+ // If the conversion context location is invalid don't complain. We also
+ // don't want to emit a warning if the issue occurs from the expansion of
+ // a system macro. The problem is that 'getSpellingLoc()' is slow, so we
+ // delay this check as long as possible. Once we detect we are in that
+ // scenario, we just return.
+ if (CC.isInvalid())
+ return;
+
+ // Diagnose implicit casts to bool.
+ if (Target->isSpecificBuiltinType(BuiltinType::Bool)) {
+ if (isa<StringLiteral>(E))
+ // Warn on string literal to bool. Checks for string literals in logical
+ // expressions, for instances, assert(0 && "error here"), is prevented
+ // by a check in AnalyzeImplicitConversions().
+ return DiagnoseImpCast(S, E, T, CC,
+ diag::warn_impcast_string_literal_to_bool);
+ if (Source->isFunctionType()) {
+ // Warn on function to bool. Checks free functions and static member
+ // functions. Weakly imported functions are excluded from the check,
+ // since it's common to test their value to check whether the linker
+ // found a definition for them.
+ ValueDecl *D = 0;
+ if (DeclRefExpr* R = dyn_cast<DeclRefExpr>(E)) {
+ D = R->getDecl();
+ } else if (MemberExpr *M = dyn_cast<MemberExpr>(E)) {
+ D = M->getMemberDecl();
+ }
+
+ if (D && !D->isWeak()) {
+ if (FunctionDecl* F = dyn_cast<FunctionDecl>(D)) {
+ S.Diag(E->getExprLoc(), diag::warn_impcast_function_to_bool)
+ << F << E->getSourceRange() << SourceRange(CC);
+ S.Diag(E->getExprLoc(), diag::note_function_to_bool_silence)
+ << FixItHint::CreateInsertion(E->getExprLoc(), "&");
+ QualType ReturnType;
+ UnresolvedSet<4> NonTemplateOverloads;
+ S.isExprCallable(*E, ReturnType, NonTemplateOverloads);
+ if (!ReturnType.isNull()
+ && ReturnType->isSpecificBuiltinType(BuiltinType::Bool))
+ S.Diag(E->getExprLoc(), diag::note_function_to_bool_call)
+ << FixItHint::CreateInsertion(
+ S.getPreprocessor().getLocForEndOfToken(E->getLocEnd()), "()");
+ return;
+ }
+ }
+ }
+ return; // Other casts to bool are not checked.
+ }
+
+ // Strip vector types.
+ if (isa<VectorType>(Source)) {
+ if (!isa<VectorType>(Target)) {
+ if (S.SourceMgr.isInSystemMacro(CC))
+ return;
+ return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_vector_scalar);
+ }
+
+ // If the vector cast is cast between two vectors of the same size, it is
+ // a bitcast, not a conversion.
+ if (S.Context.getTypeSize(Source) == S.Context.getTypeSize(Target))
+ return;
+
+ Source = cast<VectorType>(Source)->getElementType().getTypePtr();
+ Target = cast<VectorType>(Target)->getElementType().getTypePtr();
+ }
+
+ // Strip complex types.
+ if (isa<ComplexType>(Source)) {
+ if (!isa<ComplexType>(Target)) {
+ if (S.SourceMgr.isInSystemMacro(CC))
+ return;
+
+ return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_complex_scalar);
+ }
+
+ Source = cast<ComplexType>(Source)->getElementType().getTypePtr();
+ Target = cast<ComplexType>(Target)->getElementType().getTypePtr();
+ }
+
+ const BuiltinType *SourceBT = dyn_cast<BuiltinType>(Source);
+ const BuiltinType *TargetBT = dyn_cast<BuiltinType>(Target);
+
+ // If the source is floating point...
+ if (SourceBT && SourceBT->isFloatingPoint()) {
+ // ...and the target is floating point...
+ if (TargetBT && TargetBT->isFloatingPoint()) {
+ // ...then warn if we're dropping FP rank.
+
+ // Builtin FP kinds are ordered by increasing FP rank.
+ if (SourceBT->getKind() > TargetBT->getKind()) {
+ // Don't warn about float constants that are precisely
+ // representable in the target type.
+ Expr::EvalResult result;
+ if (E->EvaluateAsRValue(result, S.Context)) {
+ // Value might be a float, a float vector, or a float complex.
+ if (IsSameFloatAfterCast(result.Val,
+ S.Context.getFloatTypeSemantics(QualType(TargetBT, 0)),
+ S.Context.getFloatTypeSemantics(QualType(SourceBT, 0))))
+ return;
+ }
+
+ if (S.SourceMgr.isInSystemMacro(CC))
+ return;
+
+ DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_float_precision);
+ }
+ return;
+ }
+
+ // If the target is integral, always warn.
+ if ((TargetBT && TargetBT->isInteger())) {
+ if (S.SourceMgr.isInSystemMacro(CC))
+ return;
+
+ Expr *InnerE = E->IgnoreParenImpCasts();
+ // We also want to warn on, e.g., "int i = -1.234"
+ if (UnaryOperator *UOp = dyn_cast<UnaryOperator>(InnerE))
+ if (UOp->getOpcode() == UO_Minus || UOp->getOpcode() == UO_Plus)
+ InnerE = UOp->getSubExpr()->IgnoreParenImpCasts();
+
+ if (FloatingLiteral *FL = dyn_cast<FloatingLiteral>(InnerE)) {
+ DiagnoseFloatingLiteralImpCast(S, FL, T, CC);
+ } else {
+ DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_float_integer);
+ }
+ }
+
+ return;
+ }
+
+ if (!Source->isIntegerType() || !Target->isIntegerType())
+ return;
+
+ if ((E->isNullPointerConstant(S.Context, Expr::NPC_ValueDependentIsNotNull)
+ == Expr::NPCK_GNUNull) && Target->isIntegerType()) {
+ SourceLocation Loc = E->getSourceRange().getBegin();
+ if (Loc.isMacroID())
+ Loc = S.SourceMgr.getImmediateExpansionRange(Loc).first;
+ S.Diag(Loc, diag::warn_impcast_null_pointer_to_integer)
+ << T << Loc << clang::SourceRange(CC);
+ return;
+ }
+
+ IntRange SourceRange = GetExprRange(S.Context, E);
+ IntRange TargetRange = IntRange::forTargetOfCanonicalType(S.Context, Target);
+
+ if (SourceRange.Width > TargetRange.Width) {
+ // If the source is a constant, use a default-on diagnostic.
+ // TODO: this should happen for bitfield stores, too.
+ llvm::APSInt Value(32);
+ if (E->isIntegerConstantExpr(Value, S.Context)) {
+ if (S.SourceMgr.isInSystemMacro(CC))
+ return;
+
+ std::string PrettySourceValue = Value.toString(10);
+ std::string PrettyTargetValue = PrettyPrintInRange(Value, TargetRange);
+
+ S.DiagRuntimeBehavior(E->getExprLoc(), E,
+ S.PDiag(diag::warn_impcast_integer_precision_constant)
+ << PrettySourceValue << PrettyTargetValue
+ << E->getType() << T << E->getSourceRange()
+ << clang::SourceRange(CC));
+ return;
+ }
+
+ // People want to build with -Wshorten-64-to-32 and not -Wconversion.
+ if (S.SourceMgr.isInSystemMacro(CC))
+ return;
+
+ if (TargetRange.Width == 32 && S.Context.getIntWidth(E->getType()) == 64)
+ return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_integer_64_32,
+ /* pruneControlFlow */ true);
+ return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_integer_precision);
+ }
+
+ if ((TargetRange.NonNegative && !SourceRange.NonNegative) ||
+ (!TargetRange.NonNegative && SourceRange.NonNegative &&
+ SourceRange.Width == TargetRange.Width)) {
+
+ if (S.SourceMgr.isInSystemMacro(CC))
+ return;
+
+ unsigned DiagID = diag::warn_impcast_integer_sign;
+
+ // Traditionally, gcc has warned about this under -Wsign-compare.
+ // We also want to warn about it in -Wconversion.
+ // So if -Wconversion is off, use a completely identical diagnostic
+ // in the sign-compare group.
+ // The conditional-checking code will
+ if (ICContext) {
+ DiagID = diag::warn_impcast_integer_sign_conditional;
+ *ICContext = true;
+ }
+
+ return DiagnoseImpCast(S, E, T, CC, DiagID);
+ }
+
+ // Diagnose conversions between different enumeration types.
+ // In C, we pretend that the type of an EnumConstantDecl is its enumeration
+ // type, to give us better diagnostics.
+ QualType SourceType = E->getType();
+ if (!S.getLangOpts().CPlusPlus) {
+ if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
+ if (EnumConstantDecl *ECD = dyn_cast<EnumConstantDecl>(DRE->getDecl())) {
+ EnumDecl *Enum = cast<EnumDecl>(ECD->getDeclContext());
+ SourceType = S.Context.getTypeDeclType(Enum);
+ Source = S.Context.getCanonicalType(SourceType).getTypePtr();
+ }
+ }
+
+ if (const EnumType *SourceEnum = Source->getAs<EnumType>())
+ if (const EnumType *TargetEnum = Target->getAs<EnumType>())
+ if ((SourceEnum->getDecl()->getIdentifier() ||
+ SourceEnum->getDecl()->getTypedefNameForAnonDecl()) &&
+ (TargetEnum->getDecl()->getIdentifier() ||
+ TargetEnum->getDecl()->getTypedefNameForAnonDecl()) &&
+ SourceEnum != TargetEnum) {
+ if (S.SourceMgr.isInSystemMacro(CC))
+ return;
+
+ return DiagnoseImpCast(S, E, SourceType, T, CC,
+ diag::warn_impcast_different_enum_types);
+ }
+
+ return;
+}
+
+void CheckConditionalOperator(Sema &S, ConditionalOperator *E, QualType T);
+
+void CheckConditionalOperand(Sema &S, Expr *E, QualType T,
+ SourceLocation CC, bool &ICContext) {
+ E = E->IgnoreParenImpCasts();
+
+ if (isa<ConditionalOperator>(E))
+ return CheckConditionalOperator(S, cast<ConditionalOperator>(E), T);
+
+ AnalyzeImplicitConversions(S, E, CC);
+ if (E->getType() != T)
+ return CheckImplicitConversion(S, E, T, CC, &ICContext);
+ return;
+}
+
+void CheckConditionalOperator(Sema &S, ConditionalOperator *E, QualType T) {
+ SourceLocation CC = E->getQuestionLoc();
+
+ AnalyzeImplicitConversions(S, E->getCond(), CC);
+
+ bool Suspicious = false;
+ CheckConditionalOperand(S, E->getTrueExpr(), T, CC, Suspicious);
+ CheckConditionalOperand(S, E->getFalseExpr(), T, CC, Suspicious);
+
+ // If -Wconversion would have warned about either of the candidates
+ // for a signedness conversion to the context type...
+ if (!Suspicious) return;
+
+ // ...but it's currently ignored...
+ if (S.Diags.getDiagnosticLevel(diag::warn_impcast_integer_sign_conditional,
+ CC))
+ return;
+
+ // ...then check whether it would have warned about either of the
+ // candidates for a signedness conversion to the condition type.
+ if (E->getType() == T) return;
+
+ Suspicious = false;
+ CheckImplicitConversion(S, E->getTrueExpr()->IgnoreParenImpCasts(),
+ E->getType(), CC, &Suspicious);
+ if (!Suspicious)
+ CheckImplicitConversion(S, E->getFalseExpr()->IgnoreParenImpCasts(),
+ E->getType(), CC, &Suspicious);
+}
+
+/// AnalyzeImplicitConversions - Find and report any interesting
+/// implicit conversions in the given expression. There are a couple
+/// of competing diagnostics here, -Wconversion and -Wsign-compare.
+void AnalyzeImplicitConversions(Sema &S, Expr *OrigE, SourceLocation CC) {
+ QualType T = OrigE->getType();
+ Expr *E = OrigE->IgnoreParenImpCasts();
+
+ if (E->isTypeDependent() || E->isValueDependent())
+ return;
+
+ // For conditional operators, we analyze the arguments as if they
+ // were being fed directly into the output.
+ if (isa<ConditionalOperator>(E)) {
+ ConditionalOperator *CO = cast<ConditionalOperator>(E);
+ CheckConditionalOperator(S, CO, T);
+ return;
+ }
+
+ // Go ahead and check any implicit conversions we might have skipped.
+ // The non-canonical typecheck is just an optimization;
+ // CheckImplicitConversion will filter out dead implicit conversions.
+ if (E->getType() != T)
+ CheckImplicitConversion(S, E, T, CC);
+
+ // Now continue drilling into this expression.
+
+ // Skip past explicit casts.
+ if (isa<ExplicitCastExpr>(E)) {
+ E = cast<ExplicitCastExpr>(E)->getSubExpr()->IgnoreParenImpCasts();
+ return AnalyzeImplicitConversions(S, E, CC);
+ }
+
+ if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
+ // Do a somewhat different check with comparison operators.
+ if (BO->isComparisonOp())
+ return AnalyzeComparison(S, BO);
+
+ // And with simple assignments.
+ if (BO->getOpcode() == BO_Assign)
+ return AnalyzeAssignment(S, BO);
+ }
+
+ // These break the otherwise-useful invariant below. Fortunately,
+ // we don't really need to recurse into them, because any internal
+ // expressions should have been analyzed already when they were
+ // built into statements.
+ if (isa<StmtExpr>(E)) return;
+
+ // Don't descend into unevaluated contexts.
+ if (isa<UnaryExprOrTypeTraitExpr>(E)) return;
+
+ // Now just recurse over the expression's children.
+ CC = E->getExprLoc();
+ BinaryOperator *BO = dyn_cast<BinaryOperator>(E);
+ bool IsLogicalOperator = BO && BO->isLogicalOp();
+ for (Stmt::child_range I = E->children(); I; ++I) {
+ Expr *ChildExpr = dyn_cast_or_null<Expr>(*I);
+ if (!ChildExpr)
+ continue;
+
+ if (IsLogicalOperator &&
+ isa<StringLiteral>(ChildExpr->IgnoreParenImpCasts()))
+ // Ignore checking string literals that are in logical operators.
+ continue;
+ AnalyzeImplicitConversions(S, ChildExpr, CC);
+ }
+}
+
+} // end anonymous namespace
+
+/// Diagnoses "dangerous" implicit conversions within the given
+/// expression (which is a full expression). Implements -Wconversion
+/// and -Wsign-compare.
+///
+/// \param CC the "context" location of the implicit conversion, i.e.
+/// the most location of the syntactic entity requiring the implicit
+/// conversion
+void Sema::CheckImplicitConversions(Expr *E, SourceLocation CC) {
+ // Don't diagnose in unevaluated contexts.
+ if (ExprEvalContexts.back().Context == Sema::Unevaluated)
+ return;
+
+ // Don't diagnose for value- or type-dependent expressions.
+ if (E->isTypeDependent() || E->isValueDependent())
+ return;
+
+ // Check for array bounds violations in cases where the check isn't triggered
+ // elsewhere for other Expr types (like BinaryOperators), e.g. when an
+ // ArraySubscriptExpr is on the RHS of a variable initialization.
+ CheckArrayAccess(E);
+
+ // This is not the right CC for (e.g.) a variable initialization.
+ AnalyzeImplicitConversions(*this, E, CC);
+}
+
+void Sema::CheckBitFieldInitialization(SourceLocation InitLoc,
+ FieldDecl *BitField,
+ Expr *Init) {
+ (void) AnalyzeBitFieldAssignment(*this, BitField, Init, InitLoc);
+}
+
+/// CheckParmsForFunctionDef - Check that the parameters of the given
+/// function are appropriate for the definition of a function. This
+/// takes care of any checks that cannot be performed on the
+/// declaration itself, e.g., that the types of each of the function
+/// parameters are complete.
+bool Sema::CheckParmsForFunctionDef(ParmVarDecl **P, ParmVarDecl **PEnd,
+ bool CheckParameterNames) {
+ bool HasInvalidParm = false;
+ for (; P != PEnd; ++P) {
+ ParmVarDecl *Param = *P;
+
+ // C99 6.7.5.3p4: the parameters in a parameter type list in a
+ // function declarator that is part of a function definition of
+ // that function shall not have incomplete type.
+ //
+ // This is also C++ [dcl.fct]p6.
+ if (!Param->isInvalidDecl() &&
+ RequireCompleteType(Param->getLocation(), Param->getType(),
+ diag::err_typecheck_decl_incomplete_type)) {
+ Param->setInvalidDecl();
+ HasInvalidParm = true;
+ }
+
+ // C99 6.9.1p5: If the declarator includes a parameter type list, the
+ // declaration of each parameter shall include an identifier.
+ if (CheckParameterNames &&
+ Param->getIdentifier() == 0 &&
+ !Param->isImplicit() &&
+ !getLangOpts().CPlusPlus)
+ Diag(Param->getLocation(), diag::err_parameter_name_omitted);
+
+ // C99 6.7.5.3p12:
+ // If the function declarator is not part of a definition of that
+ // function, parameters may have incomplete type and may use the [*]
+ // notation in their sequences of declarator specifiers to specify
+ // variable length array types.
+ QualType PType = Param->getOriginalType();
+ if (const ArrayType *AT = Context.getAsArrayType(PType)) {
+ if (AT->getSizeModifier() == ArrayType::Star) {
+ // FIXME: This diagnosic should point the the '[*]' if source-location
+ // information is added for it.
+ Diag(Param->getLocation(), diag::err_array_star_in_function_definition);
+ }
+ }
+ }
+
+ return HasInvalidParm;
+}
+
+/// CheckCastAlign - Implements -Wcast-align, which warns when a
+/// pointer cast increases the alignment requirements.
+void Sema::CheckCastAlign(Expr *Op, QualType T, SourceRange TRange) {
+ // This is actually a lot of work to potentially be doing on every
+ // cast; don't do it if we're ignoring -Wcast_align (as is the default).
+ if (getDiagnostics().getDiagnosticLevel(diag::warn_cast_align,
+ TRange.getBegin())
+ == DiagnosticsEngine::Ignored)
+ return;
+
+ // Ignore dependent types.
+ if (T->isDependentType() || Op->getType()->isDependentType())
+ return;
+
+ // Require that the destination be a pointer type.
+ const PointerType *DestPtr = T->getAs<PointerType>();
+ if (!DestPtr) return;
+
+ // If the destination has alignment 1, we're done.
+ QualType DestPointee = DestPtr->getPointeeType();
+ if (DestPointee->isIncompleteType()) return;
+ CharUnits DestAlign = Context.getTypeAlignInChars(DestPointee);
+ if (DestAlign.isOne()) return;
+
+ // Require that the source be a pointer type.
+ const PointerType *SrcPtr = Op->getType()->getAs<PointerType>();
+ if (!SrcPtr) return;
+ QualType SrcPointee = SrcPtr->getPointeeType();
+
+ // Whitelist casts from cv void*. We already implicitly
+ // whitelisted casts to cv void*, since they have alignment 1.
+ // Also whitelist casts involving incomplete types, which implicitly
+ // includes 'void'.
+ if (SrcPointee->isIncompleteType()) return;
+
+ CharUnits SrcAlign = Context.getTypeAlignInChars(SrcPointee);
+ if (SrcAlign >= DestAlign) return;
+
+ Diag(TRange.getBegin(), diag::warn_cast_align)
+ << Op->getType() << T
+ << static_cast<unsigned>(SrcAlign.getQuantity())
+ << static_cast<unsigned>(DestAlign.getQuantity())
+ << TRange << Op->getSourceRange();
+}
+
+static const Type* getElementType(const Expr *BaseExpr) {
+ const Type* EltType = BaseExpr->getType().getTypePtr();
+ if (EltType->isAnyPointerType())
+ return EltType->getPointeeType().getTypePtr();
+ else if (EltType->isArrayType())
+ return EltType->getBaseElementTypeUnsafe();
+ return EltType;
+}
+
+/// \brief Check whether this array fits the idiom of a size-one tail padded
+/// array member of a struct.
+///
+/// We avoid emitting out-of-bounds access warnings for such arrays as they are
+/// commonly used to emulate flexible arrays in C89 code.
+static bool IsTailPaddedMemberArray(Sema &S, llvm::APInt Size,
+ const NamedDecl *ND) {
+ if (Size != 1 || !ND) return false;
+
+ const FieldDecl *FD = dyn_cast<FieldDecl>(ND);
+ if (!FD) return false;
+
+ // Don't consider sizes resulting from macro expansions or template argument
+ // substitution to form C89 tail-padded arrays.
+ ConstantArrayTypeLoc TL =
+ cast<ConstantArrayTypeLoc>(FD->getTypeSourceInfo()->getTypeLoc());
+ const Expr *SizeExpr = dyn_cast<IntegerLiteral>(TL.getSizeExpr());
+ if (!SizeExpr || SizeExpr->getExprLoc().isMacroID())
+ return false;
+
+ const RecordDecl *RD = dyn_cast<RecordDecl>(FD->getDeclContext());
+ if (!RD) return false;
+ if (RD->isUnion()) return false;
+ if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) {
+ if (!CRD->isStandardLayout()) return false;
+ }
+
+ // See if this is the last field decl in the record.
+ const Decl *D = FD;
+ while ((D = D->getNextDeclInContext()))
+ if (isa<FieldDecl>(D))
+ return false;
+ return true;
+}
+
+void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr,
+ const ArraySubscriptExpr *ASE,
+ bool AllowOnePastEnd, bool IndexNegated) {
+ IndexExpr = IndexExpr->IgnoreParenImpCasts();
+ if (IndexExpr->isValueDependent())
+ return;
+
+ const Type *EffectiveType = getElementType(BaseExpr);
+ BaseExpr = BaseExpr->IgnoreParenCasts();
+ const ConstantArrayType *ArrayTy =
+ Context.getAsConstantArrayType(BaseExpr->getType());
+ if (!ArrayTy)
+ return;
+
+ llvm::APSInt index;
+ if (!IndexExpr->EvaluateAsInt(index, Context))
+ return;
+ if (IndexNegated)
+ index = -index;
+
+ const NamedDecl *ND = NULL;
+ if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(BaseExpr))
+ ND = dyn_cast<NamedDecl>(DRE->getDecl());
+ if (const MemberExpr *ME = dyn_cast<MemberExpr>(BaseExpr))
+ ND = dyn_cast<NamedDecl>(ME->getMemberDecl());
+
+ if (index.isUnsigned() || !index.isNegative()) {
+ llvm::APInt size = ArrayTy->getSize();
+ if (!size.isStrictlyPositive())
+ return;
+
+ const Type* BaseType = getElementType(BaseExpr);
+ if (BaseType != EffectiveType) {
+ // Make sure we're comparing apples to apples when comparing index to size
+ uint64_t ptrarith_typesize = Context.getTypeSize(EffectiveType);
+ uint64_t array_typesize = Context.getTypeSize(BaseType);
+ // Handle ptrarith_typesize being zero, such as when casting to void*
+ if (!ptrarith_typesize) ptrarith_typesize = 1;
+ if (ptrarith_typesize != array_typesize) {
+ // There's a cast to a different size type involved
+ uint64_t ratio = array_typesize / ptrarith_typesize;
+ // TODO: Be smarter about handling cases where array_typesize is not a
+ // multiple of ptrarith_typesize
+ if (ptrarith_typesize * ratio == array_typesize)
+ size *= llvm::APInt(size.getBitWidth(), ratio);
+ }
+ }
+
+ if (size.getBitWidth() > index.getBitWidth())
+ index = index.zext(size.getBitWidth());
+ else if (size.getBitWidth() < index.getBitWidth())
+ size = size.zext(index.getBitWidth());
+
+ // For array subscripting the index must be less than size, but for pointer
+ // arithmetic also allow the index (offset) to be equal to size since
+ // computing the next address after the end of the array is legal and
+ // commonly done e.g. in C++ iterators and range-based for loops.
+ if (AllowOnePastEnd ? index.ule(size) : index.ult(size))
+ return;
+
+ // Also don't warn for arrays of size 1 which are members of some
+ // structure. These are often used to approximate flexible arrays in C89
+ // code.
+ if (IsTailPaddedMemberArray(*this, size, ND))
+ return;
+
+ // Suppress the warning if the subscript expression (as identified by the
+ // ']' location) and the index expression are both from macro expansions
+ // within a system header.
+ if (ASE) {
+ SourceLocation RBracketLoc = SourceMgr.getSpellingLoc(
+ ASE->getRBracketLoc());
+ if (SourceMgr.isInSystemHeader(RBracketLoc)) {
+ SourceLocation IndexLoc = SourceMgr.getSpellingLoc(
+ IndexExpr->getLocStart());
+ if (SourceMgr.isFromSameFile(RBracketLoc, IndexLoc))
+ return;
+ }
+ }
+
+ unsigned DiagID = diag::warn_ptr_arith_exceeds_bounds;
+ if (ASE)
+ DiagID = diag::warn_array_index_exceeds_bounds;
+
+ DiagRuntimeBehavior(BaseExpr->getLocStart(), BaseExpr,
+ PDiag(DiagID) << index.toString(10, true)
+ << size.toString(10, true)
+ << (unsigned)size.getLimitedValue(~0U)
+ << IndexExpr->getSourceRange());
+ } else {
+ unsigned DiagID = diag::warn_array_index_precedes_bounds;
+ if (!ASE) {
+ DiagID = diag::warn_ptr_arith_precedes_bounds;
+ if (index.isNegative()) index = -index;
+ }
+
+ DiagRuntimeBehavior(BaseExpr->getLocStart(), BaseExpr,
+ PDiag(DiagID) << index.toString(10, true)
+ << IndexExpr->getSourceRange());
+ }
+
+ if (!ND) {
+ // Try harder to find a NamedDecl to point at in the note.
+ while (const ArraySubscriptExpr *ASE =
+ dyn_cast<ArraySubscriptExpr>(BaseExpr))
+ BaseExpr = ASE->getBase()->IgnoreParenCasts();
+ if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(BaseExpr))
+ ND = dyn_cast<NamedDecl>(DRE->getDecl());
+ if (const MemberExpr *ME = dyn_cast<MemberExpr>(BaseExpr))
+ ND = dyn_cast<NamedDecl>(ME->getMemberDecl());
+ }
+
+ if (ND)
+ DiagRuntimeBehavior(ND->getLocStart(), BaseExpr,
+ PDiag(diag::note_array_index_out_of_bounds)
+ << ND->getDeclName());
+}
+
+void Sema::CheckArrayAccess(const Expr *expr) {
+ int AllowOnePastEnd = 0;
+ while (expr) {
+ expr = expr->IgnoreParenImpCasts();
+ switch (expr->getStmtClass()) {
+ case Stmt::ArraySubscriptExprClass: {
+ const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(expr);
+ CheckArrayAccess(ASE->getBase(), ASE->getIdx(), ASE,
+ AllowOnePastEnd > 0);
+ return;
+ }
+ case Stmt::UnaryOperatorClass: {
+ // Only unwrap the * and & unary operators
+ const UnaryOperator *UO = cast<UnaryOperator>(expr);
+ expr = UO->getSubExpr();
+ switch (UO->getOpcode()) {
+ case UO_AddrOf:
+ AllowOnePastEnd++;
+ break;
+ case UO_Deref:
+ AllowOnePastEnd--;
+ break;
+ default:
+ return;
+ }
+ break;
+ }
+ case Stmt::ConditionalOperatorClass: {
+ const ConditionalOperator *cond = cast<ConditionalOperator>(expr);
+ if (const Expr *lhs = cond->getLHS())
+ CheckArrayAccess(lhs);
+ if (const Expr *rhs = cond->getRHS())
+ CheckArrayAccess(rhs);
+ return;
+ }
+ default:
+ return;
+ }
+ }
+}
+
+//===--- CHECK: Objective-C retain cycles ----------------------------------//
+
+namespace {
+ struct RetainCycleOwner {
+ RetainCycleOwner() : Variable(0), Indirect(false) {}
+ VarDecl *Variable;
+ SourceRange Range;
+ SourceLocation Loc;
+ bool Indirect;
+
+ void setLocsFrom(Expr *e) {
+ Loc = e->getExprLoc();
+ Range = e->getSourceRange();
+ }
+ };
+}
+
+/// Consider whether capturing the given variable can possibly lead to
+/// a retain cycle.
+static bool considerVariable(VarDecl *var, Expr *ref, RetainCycleOwner &owner) {
+ // In ARC, it's captured strongly iff the variable has __strong
+ // lifetime. In MRR, it's captured strongly if the variable is
+ // __block and has an appropriate type.
+ if (var->getType().getObjCLifetime() != Qualifiers::OCL_Strong)
+ return false;
+
+ owner.Variable = var;
+ owner.setLocsFrom(ref);
+ return true;
+}
+
+static bool findRetainCycleOwner(Sema &S, Expr *e, RetainCycleOwner &owner) {
+ while (true) {
+ e = e->IgnoreParens();
+ if (CastExpr *cast = dyn_cast<CastExpr>(e)) {
+ switch (cast->getCastKind()) {
+ case CK_BitCast:
+ case CK_LValueBitCast:
+ case CK_LValueToRValue:
+ case CK_ARCReclaimReturnedObject:
+ e = cast->getSubExpr();
+ continue;
+
+ default:
+ return false;
+ }
+ }
+
+ if (ObjCIvarRefExpr *ref = dyn_cast<ObjCIvarRefExpr>(e)) {
+ ObjCIvarDecl *ivar = ref->getDecl();
+ if (ivar->getType().getObjCLifetime() != Qualifiers::OCL_Strong)
+ return false;
+
+ // Try to find a retain cycle in the base.
+ if (!findRetainCycleOwner(S, ref->getBase(), owner))
+ return false;
+
+ if (ref->isFreeIvar()) owner.setLocsFrom(ref);
+ owner.Indirect = true;
+ return true;
+ }
+
+ if (DeclRefExpr *ref = dyn_cast<DeclRefExpr>(e)) {
+ VarDecl *var = dyn_cast<VarDecl>(ref->getDecl());
+ if (!var) return false;
+ return considerVariable(var, ref, owner);
+ }
+
+ if (MemberExpr *member = dyn_cast<MemberExpr>(e)) {
+ if (member->isArrow()) return false;
+
+ // Don't count this as an indirect ownership.
+ e = member->getBase();
+ continue;
+ }
+
+ if (PseudoObjectExpr *pseudo = dyn_cast<PseudoObjectExpr>(e)) {
+ // Only pay attention to pseudo-objects on property references.
+ ObjCPropertyRefExpr *pre
+ = dyn_cast<ObjCPropertyRefExpr>(pseudo->getSyntacticForm()
+ ->IgnoreParens());
+ if (!pre) return false;
+ if (pre->isImplicitProperty()) return false;
+ ObjCPropertyDecl *property = pre->getExplicitProperty();
+ if (!property->isRetaining() &&
+ !(property->getPropertyIvarDecl() &&
+ property->getPropertyIvarDecl()->getType()
+ .getObjCLifetime() == Qualifiers::OCL_Strong))
+ return false;
+
+ owner.Indirect = true;
+ if (pre->isSuperReceiver()) {
+ owner.Variable = S.getCurMethodDecl()->getSelfDecl();
+ if (!owner.Variable)
+ return false;
+ owner.Loc = pre->getLocation();
+ owner.Range = pre->getSourceRange();
+ return true;
+ }
+ e = const_cast<Expr*>(cast<OpaqueValueExpr>(pre->getBase())
+ ->getSourceExpr());
+ continue;
+ }
+
+ // Array ivars?
+
+ return false;
+ }
+}
+
+namespace {
+ struct FindCaptureVisitor : EvaluatedExprVisitor<FindCaptureVisitor> {
+ FindCaptureVisitor(ASTContext &Context, VarDecl *variable)
+ : EvaluatedExprVisitor<FindCaptureVisitor>(Context),
+ Variable(variable), Capturer(0) {}
+
+ VarDecl *Variable;
+ Expr *Capturer;
+
+ void VisitDeclRefExpr(DeclRefExpr *ref) {
+ if (ref->getDecl() == Variable && !Capturer)
+ Capturer = ref;
+ }
+
+ void VisitObjCIvarRefExpr(ObjCIvarRefExpr *ref) {
+ if (Capturer) return;
+ Visit(ref->getBase());
+ if (Capturer && ref->isFreeIvar())
+ Capturer = ref;
+ }
+
+ void VisitBlockExpr(BlockExpr *block) {
+ // Look inside nested blocks
+ if (block->getBlockDecl()->capturesVariable(Variable))
+ Visit(block->getBlockDecl()->getBody());
+ }
+ };
+}
+
+/// Check whether the given argument is a block which captures a
+/// variable.
+static Expr *findCapturingExpr(Sema &S, Expr *e, RetainCycleOwner &owner) {
+ assert(owner.Variable && owner.Loc.isValid());
+
+ e = e->IgnoreParenCasts();
+ BlockExpr *block = dyn_cast<BlockExpr>(e);
+ if (!block || !block->getBlockDecl()->capturesVariable(owner.Variable))
+ return 0;
+
+ FindCaptureVisitor visitor(S.Context, owner.Variable);
+ visitor.Visit(block->getBlockDecl()->getBody());
+ return visitor.Capturer;
+}
+
+static void diagnoseRetainCycle(Sema &S, Expr *capturer,
+ RetainCycleOwner &owner) {
+ assert(capturer);
+ assert(owner.Variable && owner.Loc.isValid());
+
+ S.Diag(capturer->getExprLoc(), diag::warn_arc_retain_cycle)
+ << owner.Variable << capturer->getSourceRange();
+ S.Diag(owner.Loc, diag::note_arc_retain_cycle_owner)
+ << owner.Indirect << owner.Range;
+}
+
+/// Check for a keyword selector that starts with the word 'add' or
+/// 'set'.
+static bool isSetterLikeSelector(Selector sel) {
+ if (sel.isUnarySelector()) return false;
+
+ StringRef str = sel.getNameForSlot(0);
+ while (!str.empty() && str.front() == '_') str = str.substr(1);
+ if (str.startswith("set"))
+ str = str.substr(3);
+ else if (str.startswith("add")) {
+ // Specially whitelist 'addOperationWithBlock:'.
+ if (sel.getNumArgs() == 1 && str.startswith("addOperationWithBlock"))
+ return false;
+ str = str.substr(3);
+ }
+ else
+ return false;
+
+ if (str.empty()) return true;
+ return !islower(str.front());
+}
+
+/// Check a message send to see if it's likely to cause a retain cycle.
+void Sema::checkRetainCycles(ObjCMessageExpr *msg) {
+ // Only check instance methods whose selector looks like a setter.
+ if (!msg->isInstanceMessage() || !isSetterLikeSelector(msg->getSelector()))
+ return;
+
+ // Try to find a variable that the receiver is strongly owned by.
+ RetainCycleOwner owner;
+ if (msg->getReceiverKind() == ObjCMessageExpr::Instance) {
+ if (!findRetainCycleOwner(*this, msg->getInstanceReceiver(), owner))
+ return;
+ } else {
+ assert(msg->getReceiverKind() == ObjCMessageExpr::SuperInstance);
+ owner.Variable = getCurMethodDecl()->getSelfDecl();
+ owner.Loc = msg->getSuperLoc();
+ owner.Range = msg->getSuperLoc();
+ }
+
+ // Check whether the receiver is captured by any of the arguments.
+ for (unsigned i = 0, e = msg->getNumArgs(); i != e; ++i)
+ if (Expr *capturer = findCapturingExpr(*this, msg->getArg(i), owner))
+ return diagnoseRetainCycle(*this, capturer, owner);
+}
+
+/// Check a property assign to see if it's likely to cause a retain cycle.
+void Sema::checkRetainCycles(Expr *receiver, Expr *argument) {
+ RetainCycleOwner owner;
+ if (!findRetainCycleOwner(*this, receiver, owner))
+ return;
+
+ if (Expr *capturer = findCapturingExpr(*this, argument, owner))
+ diagnoseRetainCycle(*this, capturer, owner);
+}
+
+bool Sema::checkUnsafeAssigns(SourceLocation Loc,
+ QualType LHS, Expr *RHS) {
+ Qualifiers::ObjCLifetime LT = LHS.getObjCLifetime();
+ if (LT != Qualifiers::OCL_Weak && LT != Qualifiers::OCL_ExplicitNone)
+ return false;
+ // strip off any implicit cast added to get to the one arc-specific
+ while (ImplicitCastExpr *cast = dyn_cast<ImplicitCastExpr>(RHS)) {
+ if (cast->getCastKind() == CK_ARCConsumeObject) {
+ Diag(Loc, diag::warn_arc_retained_assign)
+ << (LT == Qualifiers::OCL_ExplicitNone)
+ << RHS->getSourceRange();
+ return true;
+ }
+ RHS = cast->getSubExpr();
+ }
+ return false;
+}
+
+void Sema::checkUnsafeExprAssigns(SourceLocation Loc,
+ Expr *LHS, Expr *RHS) {
+ QualType LHSType;
+ // PropertyRef on LHS type need be directly obtained from
+ // its declaration as it has a PsuedoType.
+ ObjCPropertyRefExpr *PRE
+ = dyn_cast<ObjCPropertyRefExpr>(LHS->IgnoreParens());
+ if (PRE && !PRE->isImplicitProperty()) {
+ const ObjCPropertyDecl *PD = PRE->getExplicitProperty();
+ if (PD)
+ LHSType = PD->getType();
+ }
+
+ if (LHSType.isNull())
+ LHSType = LHS->getType();
+ if (checkUnsafeAssigns(Loc, LHSType, RHS))
+ return;
+ Qualifiers::ObjCLifetime LT = LHSType.getObjCLifetime();
+ // FIXME. Check for other life times.
+ if (LT != Qualifiers::OCL_None)
+ return;
+
+ if (PRE) {
+ if (PRE->isImplicitProperty())
+ return;
+ const ObjCPropertyDecl *PD = PRE->getExplicitProperty();
+ if (!PD)
+ return;
+
+ unsigned Attributes = PD->getPropertyAttributes();
+ if (Attributes & ObjCPropertyDecl::OBJC_PR_assign) {
+ // when 'assign' attribute was not explicitly specified
+ // by user, ignore it and rely on property type itself
+ // for lifetime info.
+ unsigned AsWrittenAttr = PD->getPropertyAttributesAsWritten();
+ if (!(AsWrittenAttr & ObjCPropertyDecl::OBJC_PR_assign) &&
+ LHSType->isObjCRetainableType())
+ return;
+
+ while (ImplicitCastExpr *cast = dyn_cast<ImplicitCastExpr>(RHS)) {
+ if (cast->getCastKind() == CK_ARCConsumeObject) {
+ Diag(Loc, diag::warn_arc_retained_property_assign)
+ << RHS->getSourceRange();
+ return;
+ }
+ RHS = cast->getSubExpr();
+ }
+ }
+ }
+}
+
+//===--- CHECK: Empty statement body (-Wempty-body) ---------------------===//
+
+namespace {
+bool ShouldDiagnoseEmptyStmtBody(const SourceManager &SourceMgr,
+ SourceLocation StmtLoc,
+ const NullStmt *Body) {
+ // Do not warn if the body is a macro that expands to nothing, e.g:
+ //
+ // #define CALL(x)
+ // if (condition)
+ // CALL(0);
+ //
+ if (Body->hasLeadingEmptyMacro())
+ return false;
+
+ // Get line numbers of statement and body.
+ bool StmtLineInvalid;
+ unsigned StmtLine = SourceMgr.getSpellingLineNumber(StmtLoc,
+ &StmtLineInvalid);
+ if (StmtLineInvalid)
+ return false;
+
+ bool BodyLineInvalid;
+ unsigned BodyLine = SourceMgr.getSpellingLineNumber(Body->getSemiLoc(),
+ &BodyLineInvalid);
+ if (BodyLineInvalid)
+ return false;
+
+ // Warn if null statement and body are on the same line.
+ if (StmtLine != BodyLine)
+ return false;
+
+ return true;
+}
+} // Unnamed namespace
+
+void Sema::DiagnoseEmptyStmtBody(SourceLocation StmtLoc,
+ const Stmt *Body,
+ unsigned DiagID) {
+ // Since this is a syntactic check, don't emit diagnostic for template
+ // instantiations, this just adds noise.
+ if (CurrentInstantiationScope)
+ return;
+
+ // The body should be a null statement.
+ const NullStmt *NBody = dyn_cast<NullStmt>(Body);
+ if (!NBody)
+ return;
+
+ // Do the usual checks.
+ if (!ShouldDiagnoseEmptyStmtBody(SourceMgr, StmtLoc, NBody))
+ return;
+
+ Diag(NBody->getSemiLoc(), DiagID);
+ Diag(NBody->getSemiLoc(), diag::note_empty_body_on_separate_line);
+}
+
+void Sema::DiagnoseEmptyLoopBody(const Stmt *S,
+ const Stmt *PossibleBody) {
+ assert(!CurrentInstantiationScope); // Ensured by caller
+
+ SourceLocation StmtLoc;
+ const Stmt *Body;
+ unsigned DiagID;
+ if (const ForStmt *FS = dyn_cast<ForStmt>(S)) {
+ StmtLoc = FS->getRParenLoc();
+ Body = FS->getBody();
+ DiagID = diag::warn_empty_for_body;
+ } else if (const WhileStmt *WS = dyn_cast<WhileStmt>(S)) {
+ StmtLoc = WS->getCond()->getSourceRange().getEnd();
+ Body = WS->getBody();
+ DiagID = diag::warn_empty_while_body;
+ } else
+ return; // Neither `for' nor `while'.
+
+ // The body should be a null statement.
+ const NullStmt *NBody = dyn_cast<NullStmt>(Body);
+ if (!NBody)
+ return;
+
+ // Skip expensive checks if diagnostic is disabled.
+ if (Diags.getDiagnosticLevel(DiagID, NBody->getSemiLoc()) ==
+ DiagnosticsEngine::Ignored)
+ return;
+
+ // Do the usual checks.
+ if (!ShouldDiagnoseEmptyStmtBody(SourceMgr, StmtLoc, NBody))
+ return;
+
+ // `for(...);' and `while(...);' are popular idioms, so in order to keep
+ // noise level low, emit diagnostics only if for/while is followed by a
+ // CompoundStmt, e.g.:
+ // for (int i = 0; i < n; i++);
+ // {
+ // a(i);
+ // }
+ // or if for/while is followed by a statement with more indentation
+ // than for/while itself:
+ // for (int i = 0; i < n; i++);
+ // a(i);
+ bool ProbableTypo = isa<CompoundStmt>(PossibleBody);
+ if (!ProbableTypo) {
+ bool BodyColInvalid;
+ unsigned BodyCol = SourceMgr.getPresumedColumnNumber(
+ PossibleBody->getLocStart(),
+ &BodyColInvalid);
+ if (BodyColInvalid)
+ return;
+
+ bool StmtColInvalid;
+ unsigned StmtCol = SourceMgr.getPresumedColumnNumber(
+ S->getLocStart(),
+ &StmtColInvalid);
+ if (StmtColInvalid)
+ return;
+
+ if (BodyCol > StmtCol)
+ ProbableTypo = true;
+ }
+
+ if (ProbableTypo) {
+ Diag(NBody->getSemiLoc(), DiagID);
+ Diag(NBody->getSemiLoc(), diag::note_empty_body_on_separate_line);
+ }
+}