Add the clang library to the repo (with some of my changes, too).

1 files changed, 426 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaAttr.cpp b/clang/lib/Sema/SemaAttr.cpp
new file mode 100644
index 0000000..e935fc7
--- /dev/null
+++ b/clang/lib/Sema/SemaAttr.cpp
@@ -0,0 +1,426 @@
+//===--- SemaAttr.cpp - Semantic Analysis for Attributes ------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements semantic analysis for non-trivial attributes and
+// pragmas.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Sema/SemaInternal.h"
+#include "clang/Sema/Lookup.h"
+#include "clang/AST/Attr.h"
+#include "clang/AST/Expr.h"
+#include "clang/Basic/TargetInfo.h"
+#include "clang/Lex/Preprocessor.h"
+using namespace clang;
+
+//===----------------------------------------------------------------------===//
+// Pragma 'pack' and 'options align'
+//===----------------------------------------------------------------------===//
+
+namespace {
+  struct PackStackEntry {
+    // We just use a sentinel to represent when the stack is set to mac68k
+    // alignment.
+    static const unsigned kMac68kAlignmentSentinel = ~0U;
+
+    unsigned Alignment;
+    IdentifierInfo *Name;
+  };
+
+  /// PragmaPackStack - Simple class to wrap the stack used by #pragma
+  /// pack.
+  class PragmaPackStack {
+    typedef std::vector<PackStackEntry> stack_ty;
+
+    /// Alignment - The current user specified alignment.
+    unsigned Alignment;
+
+    /// Stack - Entries in the #pragma pack stack, consisting of saved
+    /// alignments and optional names.
+    stack_ty Stack;
+
+  public:
+    PragmaPackStack() : Alignment(0) {}
+
+    void setAlignment(unsigned A) { Alignment = A; }
+    unsigned getAlignment() { return Alignment; }
+
+    /// push - Push the current alignment onto the stack, optionally
+    /// using the given \arg Name for the record, if non-zero.
+    void push(IdentifierInfo *Name) {
+      PackStackEntry PSE = { Alignment, Name };
+      Stack.push_back(PSE);
+    }
+
+    /// pop - Pop a record from the stack and restore the current
+    /// alignment to the previous value. If \arg Name is non-zero then
+    /// the first such named record is popped, otherwise the top record
+    /// is popped. Returns true if the pop succeeded.
+    bool pop(IdentifierInfo *Name, bool IsReset);
+  };
+}  // end anonymous namespace.
+
+bool PragmaPackStack::pop(IdentifierInfo *Name, bool IsReset) {
+  // If name is empty just pop top.
+  if (!Name) {
+    // An empty stack is a special case...
+    if (Stack.empty()) {
+      // If this isn't a reset, it is always an error.
+      if (!IsReset)
+        return false;
+
+      // Otherwise, it is an error only if some alignment has been set.
+      if (!Alignment)
+        return false;
+
+      // Otherwise, reset to the default alignment.
+      Alignment = 0;
+    } else {
+      Alignment = Stack.back().Alignment;
+      Stack.pop_back();
+    }
+
+    return true;
+  }
+
+  // Otherwise, find the named record.
+  for (unsigned i = Stack.size(); i != 0; ) {
+    --i;
+    if (Stack[i].Name == Name) {
+      // Found it, pop up to and including this record.
+      Alignment = Stack[i].Alignment;
+      Stack.erase(Stack.begin() + i, Stack.end());
+      return true;
+    }
+  }
+
+  return false;
+}
+
+
+/// FreePackedContext - Deallocate and null out PackContext.
+void Sema::FreePackedContext() {
+  delete static_cast<PragmaPackStack*>(PackContext);
+  PackContext = 0;
+}
+
+void Sema::AddAlignmentAttributesForRecord(RecordDecl *RD) {
+  // If there is no pack context, we don't need any attributes.
+  if (!PackContext)
+    return;
+
+  PragmaPackStack *Stack = static_cast<PragmaPackStack*>(PackContext);
+
+  // Otherwise, check to see if we need a max field alignment attribute.
+  if (unsigned Alignment = Stack->getAlignment()) {
+    if (Alignment == PackStackEntry::kMac68kAlignmentSentinel)
+      RD->addAttr(::new (Context) AlignMac68kAttr(SourceLocation(), Context));
+    else
+      RD->addAttr(::new (Context) MaxFieldAlignmentAttr(SourceLocation(),
+                                                        Context,
+                                                        Alignment * 8));
+  }
+}
+
+void Sema::AddMsStructLayoutForRecord(RecordDecl *RD) {
+  if (!MSStructPragmaOn)
+    return;
+  RD->addAttr(::new (Context) MsStructAttr(SourceLocation(), Context));
+}
+
+void Sema::ActOnPragmaOptionsAlign(PragmaOptionsAlignKind Kind,
+                                   SourceLocation PragmaLoc,
+                                   SourceLocation KindLoc) {
+  if (PackContext == 0)
+    PackContext = new PragmaPackStack();
+
+  PragmaPackStack *Context = static_cast<PragmaPackStack*>(PackContext);
+
+  // Reset just pops the top of the stack, or resets the current alignment to
+  // default.
+  if (Kind == Sema::POAK_Reset) {
+    if (!Context->pop(0, /*IsReset=*/true)) {
+      Diag(PragmaLoc, diag::warn_pragma_options_align_reset_failed)
+        << "stack empty";
+    }
+    return;
+  }
+
+  switch (Kind) {
+    // For all targets we support native and natural are the same.
+    //
+    // FIXME: This is not true on Darwin/PPC.
+  case POAK_Native:
+  case POAK_Power:
+  case POAK_Natural:
+    Context->push(0);
+    Context->setAlignment(0);
+    break;
+
+    // Note that '#pragma options align=packed' is not equivalent to attribute
+    // packed, it has a different precedence relative to attribute aligned.
+  case POAK_Packed:
+    Context->push(0);
+    Context->setAlignment(1);
+    break;
+
+  case POAK_Mac68k:
+    // Check if the target supports this.
+    if (!PP.getTargetInfo().hasAlignMac68kSupport()) {
+      Diag(PragmaLoc, diag::err_pragma_options_align_mac68k_target_unsupported);
+      return;
+    }
+    Context->push(0);
+    Context->setAlignment(PackStackEntry::kMac68kAlignmentSentinel);
+    break;
+
+  default:
+    Diag(PragmaLoc, diag::warn_pragma_options_align_unsupported_option)
+      << KindLoc;
+    break;
+  }
+}
+
+void Sema::ActOnPragmaPack(PragmaPackKind Kind, IdentifierInfo *Name,
+                           Expr *alignment, SourceLocation PragmaLoc,
+                           SourceLocation LParenLoc, SourceLocation RParenLoc) {
+  Expr *Alignment = static_cast<Expr *>(alignment);
+
+  // If specified then alignment must be a "small" power of two.
+  unsigned AlignmentVal = 0;
+  if (Alignment) {
+    llvm::APSInt Val;
+
+    // pack(0) is like pack(), which just works out since that is what
+    // we use 0 for in PackAttr.
+    if (Alignment->isTypeDependent() ||
+        Alignment->isValueDependent() ||
+        !Alignment->isIntegerConstantExpr(Val, Context) ||
+        !(Val == 0 || Val.isPowerOf2()) ||
+        Val.getZExtValue() > 16) {
+      Diag(PragmaLoc, diag::warn_pragma_pack_invalid_alignment);
+      return; // Ignore
+    }
+
+    AlignmentVal = (unsigned) Val.getZExtValue();
+  }
+
+  if (PackContext == 0)
+    PackContext = new PragmaPackStack();
+
+  PragmaPackStack *Context = static_cast<PragmaPackStack*>(PackContext);
+
+  switch (Kind) {
+  case Sema::PPK_Default: // pack([n])
+    Context->setAlignment(AlignmentVal);
+    break;
+
+  case Sema::PPK_Show: // pack(show)
+    // Show the current alignment, making sure to show the right value
+    // for the default.
+    AlignmentVal = Context->getAlignment();
+    // FIXME: This should come from the target.
+    if (AlignmentVal == 0)
+      AlignmentVal = 8;
+    if (AlignmentVal == PackStackEntry::kMac68kAlignmentSentinel)
+      Diag(PragmaLoc, diag::warn_pragma_pack_show) << "mac68k";
+    else
+      Diag(PragmaLoc, diag::warn_pragma_pack_show) << AlignmentVal;
+    break;
+
+  case Sema::PPK_Push: // pack(push [, id] [, [n])
+    Context->push(Name);
+    // Set the new alignment if specified.
+    if (Alignment)
+      Context->setAlignment(AlignmentVal);
+    break;
+
+  case Sema::PPK_Pop: // pack(pop [, id] [,  n])
+    // MSDN, C/C++ Preprocessor Reference > Pragma Directives > pack:
+    // "#pragma pack(pop, identifier, n) is undefined"
+    if (Alignment && Name)
+      Diag(PragmaLoc, diag::warn_pragma_pack_pop_identifer_and_alignment);
+
+    // Do the pop.
+    if (!Context->pop(Name, /*IsReset=*/false)) {
+      // If a name was specified then failure indicates the name
+      // wasn't found. Otherwise failure indicates the stack was
+      // empty.
+      Diag(PragmaLoc, diag::warn_pragma_pack_pop_failed)
+        << (Name ? "no record matching name" : "stack empty");
+
+      // FIXME: Warn about popping named records as MSVC does.
+    } else {
+      // Pop succeeded, set the new alignment if specified.
+      if (Alignment)
+        Context->setAlignment(AlignmentVal);
+    }
+    break;
+  }
+}
+
+void Sema::ActOnPragmaMSStruct(PragmaMSStructKind Kind) { 
+  MSStructPragmaOn = (Kind == PMSST_ON);
+}
+
+void Sema::ActOnPragmaUnused(const Token &IdTok, Scope *curScope,
+                             SourceLocation PragmaLoc) {
+
+  IdentifierInfo *Name = IdTok.getIdentifierInfo();
+  LookupResult Lookup(*this, Name, IdTok.getLocation(), LookupOrdinaryName);
+  LookupParsedName(Lookup, curScope, NULL, true);
+
+  if (Lookup.empty()) {
+    Diag(PragmaLoc, diag::warn_pragma_unused_undeclared_var)
+      << Name << SourceRange(IdTok.getLocation());
+    return;
+  }
+
+  VarDecl *VD = Lookup.getAsSingle<VarDecl>();
+  if (!VD) {
+    Diag(PragmaLoc, diag::warn_pragma_unused_expected_var_arg)
+      << Name << SourceRange(IdTok.getLocation());
+    return;
+  }
+
+  // Warn if this was used before being marked unused.
+  if (VD->isUsed())
+    Diag(PragmaLoc, diag::warn_used_but_marked_unused) << Name;
+
+  VD->addAttr(::new (Context) UnusedAttr(IdTok.getLocation(), Context));
+}
+
+void Sema::AddCFAuditedAttribute(Decl *D) {
+  SourceLocation Loc = PP.getPragmaARCCFCodeAuditedLoc();
+  if (!Loc.isValid()) return;
+
+  // Don't add a redundant or conflicting attribute.
+  if (D->hasAttr<CFAuditedTransferAttr>() ||
+      D->hasAttr<CFUnknownTransferAttr>())
+    return;
+
+  D->addAttr(::new (Context) CFAuditedTransferAttr(Loc, Context));
+}
+
+typedef std::vector<std::pair<unsigned, SourceLocation> > VisStack;
+enum { NoVisibility = (unsigned) -1 };
+
+void Sema::AddPushedVisibilityAttribute(Decl *D) {
+  if (!VisContext)
+    return;
+
+  if (isa<NamedDecl>(D) && cast<NamedDecl>(D)->getExplicitVisibility())
+    return;
+
+  VisStack *Stack = static_cast<VisStack*>(VisContext);
+  unsigned rawType = Stack->back().first;
+  if (rawType == NoVisibility) return;
+
+  VisibilityAttr::VisibilityType type
+    = (VisibilityAttr::VisibilityType) rawType;
+  SourceLocation loc = Stack->back().second;
+
+  D->addAttr(::new (Context) VisibilityAttr(loc, Context, type));
+}
+
+/// FreeVisContext - Deallocate and null out VisContext.
+void Sema::FreeVisContext() {
+  delete static_cast<VisStack*>(VisContext);
+  VisContext = 0;
+}
+
+static void PushPragmaVisibility(Sema &S, unsigned type, SourceLocation loc) {
+  // Put visibility on stack.
+  if (!S.VisContext)
+    S.VisContext = new VisStack;
+
+  VisStack *Stack = static_cast<VisStack*>(S.VisContext);
+  Stack->push_back(std::make_pair(type, loc));
+}
+
+void Sema::ActOnPragmaVisibility(const IdentifierInfo* VisType,
+                                 SourceLocation PragmaLoc) {
+  if (VisType) {
+    // Compute visibility to use.
+    VisibilityAttr::VisibilityType type;
+    if (VisType->isStr("default"))
+      type = VisibilityAttr::Default;
+    else if (VisType->isStr("hidden"))
+      type = VisibilityAttr::Hidden;
+    else if (VisType->isStr("internal"))
+      type = VisibilityAttr::Hidden; // FIXME
+    else if (VisType->isStr("protected"))
+      type = VisibilityAttr::Protected;
+    else {
+      Diag(PragmaLoc, diag::warn_attribute_unknown_visibility) <<
+        VisType->getName();
+      return;
+    }
+    PushPragmaVisibility(*this, type, PragmaLoc);
+  } else {
+    PopPragmaVisibility(false, PragmaLoc);
+  }
+}
+
+void Sema::ActOnPragmaFPContract(tok::OnOffSwitch OOS) {
+  switch (OOS) {
+  case tok::OOS_ON:
+    FPFeatures.fp_contract = 1;
+    break;
+  case tok::OOS_OFF:
+    FPFeatures.fp_contract = 0; 
+    break;
+  case tok::OOS_DEFAULT:
+    FPFeatures.fp_contract = getLangOpts().DefaultFPContract;
+    break;
+  }
+}
+
+void Sema::PushNamespaceVisibilityAttr(const VisibilityAttr *Attr,
+                                       SourceLocation Loc) {
+  // Visibility calculations will consider the namespace's visibility.
+  // Here we just want to note that we're in a visibility context
+  // which overrides any enclosing #pragma context, but doesn't itself
+  // contribute visibility.
+  PushPragmaVisibility(*this, NoVisibility, Loc);
+}
+
+void Sema::PopPragmaVisibility(bool IsNamespaceEnd, SourceLocation EndLoc) {
+  if (!VisContext) {
+    Diag(EndLoc, diag::err_pragma_pop_visibility_mismatch);
+    return;
+  }
+
+  // Pop visibility from stack
+  VisStack *Stack = static_cast<VisStack*>(VisContext);
+
+  const std::pair<unsigned, SourceLocation> *Back = &Stack->back();
+  bool StartsWithPragma = Back->first != NoVisibility;
+  if (StartsWithPragma && IsNamespaceEnd) {
+    Diag(Back->second, diag::err_pragma_push_visibility_mismatch);
+    Diag(EndLoc, diag::note_surrounding_namespace_ends_here);
+
+    // For better error recovery, eat all pushes inside the namespace.
+    do {
+      Stack->pop_back();
+      Back = &Stack->back();
+      StartsWithPragma = Back->first != NoVisibility;
+    } while (StartsWithPragma);
+  } else if (!StartsWithPragma && !IsNamespaceEnd) {
+    Diag(EndLoc, diag::err_pragma_pop_visibility_mismatch);
+    Diag(Back->second, diag::note_surrounding_namespace_starts_here);
+    return;
+  }
+
+  Stack->pop_back();
+  // To simplify the implementation, never keep around an empty stack.
+  if (Stack->empty())
+    FreeVisContext();
+}