Merge branch 'master' of ssh://bitbucket.org/czan/honours

1 files changed, 542 insertions, 0 deletions

diff --git a/clang/lib/ARCMigrate/Transforms.cpp b/clang/lib/ARCMigrate/Transforms.cpp
new file mode 100644
index 0000000..d342d1a
--- /dev/null
+++ b/clang/lib/ARCMigrate/Transforms.cpp
@@ -0,0 +1,542 @@
+//===--- Tranforms.cpp - Tranformations to ARC mode -----------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Transforms.h"
+#include "Internals.h"
+#include "clang/Sema/SemaDiagnostic.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/AST/StmtVisitor.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Basic/SourceManager.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "llvm/ADT/DenseSet.h"
+#include <map>
+
+using namespace clang;
+using namespace arcmt;
+using namespace trans;
+
+ASTTraverser::~ASTTraverser() { }
+
+//===----------------------------------------------------------------------===//
+// Helpers.
+//===----------------------------------------------------------------------===//
+
+bool trans::canApplyWeak(ASTContext &Ctx, QualType type,
+                         bool AllowOnUnknownClass) {
+  if (!Ctx.getLangOpts().ObjCRuntimeHasWeak)
+    return false;
+
+  QualType T = type;
+  if (T.isNull())
+    return false;
+
+  // iOS is always safe to use 'weak'.
+  if (Ctx.getTargetInfo().getTriple().getOS() == llvm::Triple::IOS)
+    AllowOnUnknownClass = true;
+
+  while (const PointerType *ptr = T->getAs<PointerType>())
+    T = ptr->getPointeeType();
+  if (const ObjCObjectPointerType *ObjT = T->getAs<ObjCObjectPointerType>()) {
+    ObjCInterfaceDecl *Class = ObjT->getInterfaceDecl();
+    if (!AllowOnUnknownClass && (!Class || Class->getName() == "NSObject"))
+      return false; // id/NSObject is not safe for weak.
+    if (!AllowOnUnknownClass && !Class->hasDefinition())
+      return false; // forward classes are not verifiable, therefore not safe.
+    if (Class->isArcWeakrefUnavailable())
+      return false;
+  }
+
+  return true;
+}
+
+/// \brief 'Loc' is the end of a statement range. This returns the location
+/// immediately after the semicolon following the statement.
+/// If no semicolon is found or the location is inside a macro, the returned
+/// source location will be invalid.
+SourceLocation trans::findLocationAfterSemi(SourceLocation loc,
+                                            ASTContext &Ctx) {
+  SourceLocation SemiLoc = findSemiAfterLocation(loc, Ctx);
+  if (SemiLoc.isInvalid())
+    return SourceLocation();
+  return SemiLoc.getLocWithOffset(1);
+}
+
+/// \brief \arg Loc is the end of a statement range. This returns the location
+/// of the semicolon following the statement.
+/// If no semicolon is found or the location is inside a macro, the returned
+/// source location will be invalid.
+SourceLocation trans::findSemiAfterLocation(SourceLocation loc,
+                                            ASTContext &Ctx) {
+  SourceManager &SM = Ctx.getSourceManager();
+  if (loc.isMacroID()) {
+    if (!Lexer::isAtEndOfMacroExpansion(loc, SM, Ctx.getLangOpts(), &loc))
+      return SourceLocation();
+  }
+  loc = Lexer::getLocForEndOfToken(loc, /*Offset=*/0, SM, Ctx.getLangOpts());
+
+  // Break down the source location.
+  std::pair<FileID, unsigned> locInfo = SM.getDecomposedLoc(loc);
+
+  // Try to load the file buffer.
+  bool invalidTemp = false;
+  StringRef file = SM.getBufferData(locInfo.first, &invalidTemp);
+  if (invalidTemp)
+    return SourceLocation();
+
+  const char *tokenBegin = file.data() + locInfo.second;
+
+  // Lex from the start of the given location.
+  Lexer lexer(SM.getLocForStartOfFile(locInfo.first),
+              Ctx.getLangOpts(),
+              file.begin(), tokenBegin, file.end());
+  Token tok;
+  lexer.LexFromRawLexer(tok);
+  if (tok.isNot(tok::semi))
+    return SourceLocation();
+
+  return tok.getLocation();
+}
+
+bool trans::hasSideEffects(Expr *E, ASTContext &Ctx) {
+  if (!E || !E->HasSideEffects(Ctx))
+    return false;
+
+  E = E->IgnoreParenCasts();
+  ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E);
+  if (!ME)
+    return true;
+  switch (ME->getMethodFamily()) {
+  case OMF_autorelease:
+  case OMF_dealloc:
+  case OMF_release:
+  case OMF_retain:
+    switch (ME->getReceiverKind()) {
+    case ObjCMessageExpr::SuperInstance:
+      return false;
+    case ObjCMessageExpr::Instance:
+      return hasSideEffects(ME->getInstanceReceiver(), Ctx);
+    default:
+      break;
+    }
+    break;
+  default:
+    break;
+  }
+
+  return true;
+}
+
+bool trans::isGlobalVar(Expr *E) {
+  E = E->IgnoreParenCasts();
+  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
+    return DRE->getDecl()->getDeclContext()->isFileContext() &&
+           DRE->getDecl()->getLinkage() == ExternalLinkage;
+  if (ConditionalOperator *condOp = dyn_cast<ConditionalOperator>(E))
+    return isGlobalVar(condOp->getTrueExpr()) &&
+           isGlobalVar(condOp->getFalseExpr());
+
+  return false;  
+}
+
+StringRef trans::getNilString(ASTContext &Ctx) {
+  if (Ctx.Idents.get("nil").hasMacroDefinition())
+    return "nil";
+  else
+    return "0";
+}
+
+namespace {
+
+class ReferenceClear : public RecursiveASTVisitor<ReferenceClear> {
+  ExprSet &Refs;
+public:
+  ReferenceClear(ExprSet &refs) : Refs(refs) { }
+  bool VisitDeclRefExpr(DeclRefExpr *E) { Refs.erase(E); return true; }
+};
+
+class ReferenceCollector : public RecursiveASTVisitor<ReferenceCollector> {
+  ValueDecl *Dcl;
+  ExprSet &Refs;
+
+public:
+  ReferenceCollector(ValueDecl *D, ExprSet &refs)
+    : Dcl(D), Refs(refs) { }
+
+  bool VisitDeclRefExpr(DeclRefExpr *E) {
+    if (E->getDecl() == Dcl)
+      Refs.insert(E);
+    return true;
+  }
+};
+
+class RemovablesCollector : public RecursiveASTVisitor<RemovablesCollector> {
+  ExprSet &Removables;
+
+public:
+  RemovablesCollector(ExprSet &removables)
+  : Removables(removables) { }
+  
+  bool shouldWalkTypesOfTypeLocs() const { return false; }
+  
+  bool TraverseStmtExpr(StmtExpr *E) {
+    CompoundStmt *S = E->getSubStmt();
+    for (CompoundStmt::body_iterator
+        I = S->body_begin(), E = S->body_end(); I != E; ++I) {
+      if (I != E - 1)
+        mark(*I);
+      TraverseStmt(*I);
+    }
+    return true;
+  }
+  
+  bool VisitCompoundStmt(CompoundStmt *S) {
+    for (CompoundStmt::body_iterator
+        I = S->body_begin(), E = S->body_end(); I != E; ++I)
+      mark(*I);
+    return true;
+  }
+  
+  bool VisitIfStmt(IfStmt *S) {
+    mark(S->getThen());
+    mark(S->getElse());
+    return true;
+  }
+  
+  bool VisitWhileStmt(WhileStmt *S) {
+    mark(S->getBody());
+    return true;
+  }
+  
+  bool VisitDoStmt(DoStmt *S) {
+    mark(S->getBody());
+    return true;
+  }
+  
+  bool VisitForStmt(ForStmt *S) {
+    mark(S->getInit());
+    mark(S->getInc());
+    mark(S->getBody());
+    return true;
+  }
+  
+private:
+  void mark(Stmt *S) {
+    if (!S) return;
+    
+    while (LabelStmt *Label = dyn_cast<LabelStmt>(S))
+      S = Label->getSubStmt();
+    S = S->IgnoreImplicit();
+    if (Expr *E = dyn_cast<Expr>(S))
+      Removables.insert(E);
+  }
+};
+
+} // end anonymous namespace
+
+void trans::clearRefsIn(Stmt *S, ExprSet &refs) {
+  ReferenceClear(refs).TraverseStmt(S);
+}
+
+void trans::collectRefs(ValueDecl *D, Stmt *S, ExprSet &refs) {
+  ReferenceCollector(D, refs).TraverseStmt(S);
+}
+
+void trans::collectRemovables(Stmt *S, ExprSet &exprs) {
+  RemovablesCollector(exprs).TraverseStmt(S);
+}
+
+//===----------------------------------------------------------------------===//
+// MigrationContext
+//===----------------------------------------------------------------------===//
+
+namespace {
+
+class ASTTransform : public RecursiveASTVisitor<ASTTransform> {
+  MigrationContext &MigrateCtx;
+  typedef RecursiveASTVisitor<ASTTransform> base;
+
+public:
+  ASTTransform(MigrationContext &MigrateCtx) : MigrateCtx(MigrateCtx) { }
+
+  bool shouldWalkTypesOfTypeLocs() const { return false; }
+
+  bool TraverseObjCImplementationDecl(ObjCImplementationDecl *D) {
+    ObjCImplementationContext ImplCtx(MigrateCtx, D);
+    for (MigrationContext::traverser_iterator
+           I = MigrateCtx.traversers_begin(),
+           E = MigrateCtx.traversers_end(); I != E; ++I)
+      (*I)->traverseObjCImplementation(ImplCtx);
+
+    return base::TraverseObjCImplementationDecl(D);
+  }
+
+  bool TraverseStmt(Stmt *rootS) {
+    if (!rootS)
+      return true;
+
+    BodyContext BodyCtx(MigrateCtx, rootS);
+    for (MigrationContext::traverser_iterator
+           I = MigrateCtx.traversers_begin(),
+           E = MigrateCtx.traversers_end(); I != E; ++I)
+      (*I)->traverseBody(BodyCtx);
+
+    return true;
+  }
+};
+
+}
+
+MigrationContext::~MigrationContext() {
+  for (traverser_iterator
+         I = traversers_begin(), E = traversers_end(); I != E; ++I)
+    delete *I;
+}
+
+bool MigrationContext::isGCOwnedNonObjC(QualType T) {
+  while (!T.isNull()) {
+    if (const AttributedType *AttrT = T->getAs<AttributedType>()) {
+      if (AttrT->getAttrKind() == AttributedType::attr_objc_ownership)
+        return !AttrT->getModifiedType()->isObjCRetainableType();
+    }
+
+    if (T->isArrayType())
+      T = Pass.Ctx.getBaseElementType(T);
+    else if (const PointerType *PT = T->getAs<PointerType>())
+      T = PT->getPointeeType();
+    else if (const ReferenceType *RT = T->getAs<ReferenceType>())
+      T = RT->getPointeeType();
+    else
+      break;
+  }
+
+  return false;
+}
+
+bool MigrationContext::rewritePropertyAttribute(StringRef fromAttr,
+                                                StringRef toAttr,
+                                                SourceLocation atLoc) {
+  if (atLoc.isMacroID())
+    return false;
+
+  SourceManager &SM = Pass.Ctx.getSourceManager();
+
+  // Break down the source location.
+  std::pair<FileID, unsigned> locInfo = SM.getDecomposedLoc(atLoc);
+
+  // Try to load the file buffer.
+  bool invalidTemp = false;
+  StringRef file = SM.getBufferData(locInfo.first, &invalidTemp);
+  if (invalidTemp)
+    return false;
+
+  const char *tokenBegin = file.data() + locInfo.second;
+
+  // Lex from the start of the given location.
+  Lexer lexer(SM.getLocForStartOfFile(locInfo.first),
+              Pass.Ctx.getLangOpts(),
+              file.begin(), tokenBegin, file.end());
+  Token tok;
+  lexer.LexFromRawLexer(tok);
+  if (tok.isNot(tok::at)) return false;
+  lexer.LexFromRawLexer(tok);
+  if (tok.isNot(tok::raw_identifier)) return false;
+  if (StringRef(tok.getRawIdentifierData(), tok.getLength())
+        != "property")
+    return false;
+  lexer.LexFromRawLexer(tok);
+  if (tok.isNot(tok::l_paren)) return false;
+  
+  Token BeforeTok = tok;
+  Token AfterTok;
+  AfterTok.startToken();
+  SourceLocation AttrLoc;
+  
+  lexer.LexFromRawLexer(tok);
+  if (tok.is(tok::r_paren))
+    return false;
+
+  while (1) {
+    if (tok.isNot(tok::raw_identifier)) return false;
+    StringRef ident(tok.getRawIdentifierData(), tok.getLength());
+    if (ident == fromAttr) {
+      if (!toAttr.empty()) {
+        Pass.TA.replaceText(tok.getLocation(), fromAttr, toAttr);
+        return true;
+      }
+      // We want to remove the attribute.
+      AttrLoc = tok.getLocation();
+    }
+
+    do {
+      lexer.LexFromRawLexer(tok);
+      if (AttrLoc.isValid() && AfterTok.is(tok::unknown))
+        AfterTok = tok;
+    } while (tok.isNot(tok::comma) && tok.isNot(tok::r_paren));
+    if (tok.is(tok::r_paren))
+      break;
+    if (AttrLoc.isInvalid())
+      BeforeTok = tok;
+    lexer.LexFromRawLexer(tok);
+  }
+
+  if (toAttr.empty() && AttrLoc.isValid() && AfterTok.isNot(tok::unknown)) {
+    // We want to remove the attribute.
+    if (BeforeTok.is(tok::l_paren) && AfterTok.is(tok::r_paren)) {
+      Pass.TA.remove(SourceRange(BeforeTok.getLocation(),
+                                 AfterTok.getLocation()));
+    } else if (BeforeTok.is(tok::l_paren) && AfterTok.is(tok::comma)) {
+      Pass.TA.remove(SourceRange(AttrLoc, AfterTok.getLocation()));
+    } else {
+      Pass.TA.remove(SourceRange(BeforeTok.getLocation(), AttrLoc));
+    }
+
+    return true;
+  }
+  
+  return false;
+}
+
+bool MigrationContext::addPropertyAttribute(StringRef attr,
+                                            SourceLocation atLoc) {
+  if (atLoc.isMacroID())
+    return false;
+
+  SourceManager &SM = Pass.Ctx.getSourceManager();
+
+  // Break down the source location.
+  std::pair<FileID, unsigned> locInfo = SM.getDecomposedLoc(atLoc);
+
+  // Try to load the file buffer.
+  bool invalidTemp = false;
+  StringRef file = SM.getBufferData(locInfo.first, &invalidTemp);
+  if (invalidTemp)
+    return false;
+
+  const char *tokenBegin = file.data() + locInfo.second;
+
+  // Lex from the start of the given location.
+  Lexer lexer(SM.getLocForStartOfFile(locInfo.first),
+              Pass.Ctx.getLangOpts(),
+              file.begin(), tokenBegin, file.end());
+  Token tok;
+  lexer.LexFromRawLexer(tok);
+  if (tok.isNot(tok::at)) return false;
+  lexer.LexFromRawLexer(tok);
+  if (tok.isNot(tok::raw_identifier)) return false;
+  if (StringRef(tok.getRawIdentifierData(), tok.getLength())
+        != "property")
+    return false;
+  lexer.LexFromRawLexer(tok);
+
+  if (tok.isNot(tok::l_paren)) {
+    Pass.TA.insert(tok.getLocation(), std::string("(") + attr.str() + ") ");
+    return true;
+  }
+  
+  lexer.LexFromRawLexer(tok);
+  if (tok.is(tok::r_paren)) {
+    Pass.TA.insert(tok.getLocation(), attr);
+    return true;
+  }
+
+  if (tok.isNot(tok::raw_identifier)) return false;
+
+  Pass.TA.insert(tok.getLocation(), std::string(attr) + ", ");
+  return true;
+}
+
+void MigrationContext::traverse(TranslationUnitDecl *TU) {
+  for (traverser_iterator
+         I = traversers_begin(), E = traversers_end(); I != E; ++I)
+    (*I)->traverseTU(*this);
+
+  ASTTransform(*this).TraverseDecl(TU);
+}
+
+static void GCRewriteFinalize(MigrationPass &pass) {
+  ASTContext &Ctx = pass.Ctx;
+  TransformActions &TA = pass.TA;
+  DeclContext *DC = Ctx.getTranslationUnitDecl();
+  Selector FinalizeSel =
+   Ctx.Selectors.getNullarySelector(&pass.Ctx.Idents.get("finalize"));
+  
+  typedef DeclContext::specific_decl_iterator<ObjCImplementationDecl>
+  impl_iterator;
+  for (impl_iterator I = impl_iterator(DC->decls_begin()),
+       E = impl_iterator(DC->decls_end()); I != E; ++I) {
+    for (ObjCImplementationDecl::instmeth_iterator
+         MI = (*I)->instmeth_begin(),
+         ME = (*I)->instmeth_end(); MI != ME; ++MI) {
+      ObjCMethodDecl *MD = *MI;
+      if (!MD->hasBody())
+        continue;
+      
+      if (MD->isInstanceMethod() && MD->getSelector() == FinalizeSel) {
+        ObjCMethodDecl *FinalizeM = MD;
+        Transaction Trans(TA);
+        TA.insert(FinalizeM->getSourceRange().getBegin(), 
+                  "#if !__has_feature(objc_arc)\n");
+        CharSourceRange::getTokenRange(FinalizeM->getSourceRange());
+        const SourceManager &SM = pass.Ctx.getSourceManager();
+        const LangOptions &LangOpts = pass.Ctx.getLangOpts();
+        bool Invalid;
+        std::string str = "\n#endif\n";
+        str += Lexer::getSourceText(
+                  CharSourceRange::getTokenRange(FinalizeM->getSourceRange()), 
+                                    SM, LangOpts, &Invalid);
+        TA.insertAfterToken(FinalizeM->getSourceRange().getEnd(), str);
+        
+        break;
+      }
+    }
+  }
+}
+
+//===----------------------------------------------------------------------===//
+// getAllTransformations.
+//===----------------------------------------------------------------------===//
+
+static void traverseAST(MigrationPass &pass) {
+  MigrationContext MigrateCtx(pass);
+
+  if (pass.isGCMigration()) {
+    MigrateCtx.addTraverser(new GCCollectableCallsTraverser);
+    MigrateCtx.addTraverser(new GCAttrsTraverser());
+  }
+  MigrateCtx.addTraverser(new PropertyRewriteTraverser());
+  MigrateCtx.addTraverser(new BlockObjCVariableTraverser());
+
+  MigrateCtx.traverse(pass.Ctx.getTranslationUnitDecl());
+}
+
+static void independentTransforms(MigrationPass &pass) {
+  rewriteAutoreleasePool(pass);
+  removeRetainReleaseDeallocFinalize(pass);
+  rewriteUnusedInitDelegate(pass);
+  removeZeroOutPropsInDeallocFinalize(pass);
+  makeAssignARCSafe(pass);
+  rewriteUnbridgedCasts(pass);
+  checkAPIUses(pass);
+  traverseAST(pass);
+}
+
+std::vector<TransformFn> arcmt::getAllTransformations(
+                                               LangOptions::GCMode OrigGCMode,
+                                               bool NoFinalizeRemoval) {
+  std::vector<TransformFn> transforms;
+
+  if (OrigGCMode ==  LangOptions::GCOnly && NoFinalizeRemoval)
+    transforms.push_back(GCRewriteFinalize);
+  transforms.push_back(independentTransforms);
+  // This depends on previous transformations removing various expressions.
+  transforms.push_back(removeEmptyStatementsAndDeallocFinalize);
+
+  return transforms;
+}