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Diffstat (limited to 'lib/ARCMigrate/TransUnbridgedCasts.cpp')
| -rw-r--r-- | lib/ARCMigrate/TransUnbridgedCasts.cpp | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/lib/ARCMigrate/TransUnbridgedCasts.cpp b/lib/ARCMigrate/TransUnbridgedCasts.cpp new file mode 100644 index 0000000..1cacd6d --- /dev/null +++ b/lib/ARCMigrate/TransUnbridgedCasts.cpp @@ -0,0 +1,203 @@ +//===--- TransUnbridgedCasts.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. +// +//===----------------------------------------------------------------------===// +// +// rewriteUnbridgedCasts: +// +// A cast of non-objc pointer to an objc one is checked. If the non-objc pointer +// is from a file-level variable, __bridge cast is used to convert it. +// For the result of a function call that we know is +1/+0, +// __bridge/__bridge_transfer is used. +// +// NSString *str = (NSString *)kUTTypePlainText; +// str = b ? kUTTypeRTF : kUTTypePlainText; +// NSString *_uuidString = (NSString *)CFUUIDCreateString(kCFAllocatorDefault, +// _uuid); +// ----> +// NSString *str = (__bridge NSString *)kUTTypePlainText; +// str = (__bridge NSString *)(b ? kUTTypeRTF : kUTTypePlainText); +// NSString *_uuidString = (__bridge_transfer NSString *) +// CFUUIDCreateString(kCFAllocatorDefault, _uuid); +// +// For a C pointer to ObjC, for casting 'self', __bridge is used. +// +// CFStringRef str = (CFStringRef)self; +// ----> +// CFStringRef str = (__bridge CFStringRef)self; +// +//===----------------------------------------------------------------------===// + +#include "Transforms.h" +#include "Internals.h" +#include "clang/Analysis/DomainSpecific/CocoaConventions.h" +#include "clang/Sema/SemaDiagnostic.h" +#include "clang/Basic/SourceManager.h" + +using namespace clang; +using namespace arcmt; +using namespace trans; +using llvm::StringRef; + +namespace { + +class UnbridgedCastRewriter : public RecursiveASTVisitor<UnbridgedCastRewriter>{ + MigrationPass &Pass; + IdentifierInfo *SelfII; +public: + UnbridgedCastRewriter(MigrationPass &pass) : Pass(pass) { + SelfII = &Pass.Ctx.Idents.get("self"); + } + + bool VisitCastExpr(CastExpr *E) { + if (E->getCastKind() != CK_AnyPointerToObjCPointerCast + && E->getCastKind() != CK_BitCast) + return true; + + QualType castType = E->getType(); + Expr *castExpr = E->getSubExpr(); + QualType castExprType = castExpr->getType(); + + if (castType->isObjCObjectPointerType() && + castExprType->isObjCObjectPointerType()) + return true; + if (!castType->isObjCObjectPointerType() && + !castExprType->isObjCObjectPointerType()) + return true; + + bool exprRetainable = castExprType->isObjCIndirectLifetimeType(); + bool castRetainable = castType->isObjCIndirectLifetimeType(); + if (exprRetainable == castRetainable) return true; + + if (castExpr->isNullPointerConstant(Pass.Ctx, + Expr::NPC_ValueDependentIsNull)) + return true; + + SourceLocation loc = castExpr->getExprLoc(); + if (loc.isValid() && Pass.Ctx.getSourceManager().isInSystemHeader(loc)) + return true; + + if (castType->isObjCObjectPointerType()) + transformNonObjCToObjCCast(E); + else + transformObjCToNonObjCCast(E); + + return true; + } + +private: + void transformNonObjCToObjCCast(CastExpr *E) { + if (!E) return; + + // Global vars are assumed that are cast as unretained. + if (isGlobalVar(E)) + if (E->getSubExpr()->getType()->isPointerType()) { + castToObjCObject(E, /*retained=*/false); + return; + } + + // If the cast is directly over the result of a Core Foundation function + // try to figure out whether it should be cast as retained or unretained. + Expr *inner = E->IgnoreParenCasts(); + if (CallExpr *callE = dyn_cast<CallExpr>(inner)) { + if (FunctionDecl *FD = callE->getDirectCallee()) { + if (FD->getAttr<CFReturnsRetainedAttr>()) { + castToObjCObject(E, /*retained=*/true); + return; + } + if (FD->getAttr<CFReturnsNotRetainedAttr>()) { + castToObjCObject(E, /*retained=*/false); + return; + } + if (FD->isGlobal() && + FD->getIdentifier() && + ento::cocoa::isRefType(E->getSubExpr()->getType(), "CF", + FD->getIdentifier()->getName())) { + StringRef fname = FD->getIdentifier()->getName(); + if (fname.endswith("Retain") || + fname.find("Create") != StringRef::npos || + fname.find("Copy") != StringRef::npos) { + castToObjCObject(E, /*retained=*/true); + return; + } + + if (fname.find("Get") != StringRef::npos) { + castToObjCObject(E, /*retained=*/false); + return; + } + } + } + } + } + + void castToObjCObject(CastExpr *E, bool retained) { + rewriteToBridgedCast(E, retained ? OBC_BridgeTransfer : OBC_Bridge); + } + + void rewriteToBridgedCast(CastExpr *E, ObjCBridgeCastKind Kind) { + TransformActions &TA = Pass.TA; + + // We will remove the compiler diagnostic. + if (!TA.hasDiagnostic(diag::err_arc_mismatched_cast, + diag::err_arc_cast_requires_bridge, + E->getLocStart())) + return; + + StringRef bridge; + switch(Kind) { + case OBC_Bridge: + bridge = "__bridge "; break; + case OBC_BridgeTransfer: + bridge = "__bridge_transfer "; break; + case OBC_BridgeRetained: + bridge = "__bridge_retained "; break; + } + + Transaction Trans(TA); + TA.clearDiagnostic(diag::err_arc_mismatched_cast, + diag::err_arc_cast_requires_bridge, + E->getLocStart()); + if (CStyleCastExpr *CCE = dyn_cast<CStyleCastExpr>(E)) { + TA.insertAfterToken(CCE->getLParenLoc(), bridge); + } else { + SourceLocation insertLoc = E->getSubExpr()->getLocStart(); + llvm::SmallString<128> newCast; + newCast += '('; + newCast += bridge; + newCast += E->getType().getAsString(Pass.Ctx.PrintingPolicy); + newCast += ')'; + + if (isa<ParenExpr>(E->getSubExpr())) { + TA.insert(insertLoc, newCast.str()); + } else { + newCast += '('; + TA.insert(insertLoc, newCast.str()); + TA.insertAfterToken(E->getLocEnd(), ")"); + } + } + } + + void transformObjCToNonObjCCast(CastExpr *E) { + if (isSelf(E->getSubExpr())) + return rewriteToBridgedCast(E, OBC_Bridge); + } + + bool isSelf(Expr *E) { + E = E->IgnoreParenLValueCasts(); + if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) + if (DRE->getDecl()->getIdentifier() == SelfII) + return true; + return false; + } +}; + +} // end anonymous namespace + +void trans::rewriteUnbridgedCasts(MigrationPass &pass) { + UnbridgedCastRewriter trans(pass); + trans.TraverseDecl(pass.Ctx.getTranslationUnitDecl()); +} |
