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Diffstat (limited to 'lib/ARCMigrate/TransUnbridgedCasts.cpp')
| -rw-r--r-- | lib/ARCMigrate/TransUnbridgedCasts.cpp | 466 |
1 files changed, 0 insertions, 466 deletions
diff --git a/lib/ARCMigrate/TransUnbridgedCasts.cpp b/lib/ARCMigrate/TransUnbridgedCasts.cpp deleted file mode 100644 index e767ad5346c30..0000000000000 --- a/lib/ARCMigrate/TransUnbridgedCasts.cpp +++ /dev/null @@ -1,466 +0,0 @@ -//===--- TransUnbridgedCasts.cpp - Transformations to ARC mode ------------===// -// -// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. -// See https://llvm.org/LICENSE.txt for license information. -// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception -// -//===----------------------------------------------------------------------===// -// -// 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/CFBridgingRelease 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 = (NSString *) -// CFBridgingRelease(CFUUIDCreateString(kCFAllocatorDefault, _uuid)); -// -// For a C pointer to ObjC, for casting 'self', __bridge is used. -// -// CFStringRef str = (CFStringRef)self; -// ----> -// CFStringRef str = (__bridge CFStringRef)self; -// -// Uses of Block_copy/Block_release macros are rewritten: -// -// c = Block_copy(b); -// Block_release(c); -// ----> -// c = [b copy]; -// <removed> -// -//===----------------------------------------------------------------------===// - -#include "Transforms.h" -#include "Internals.h" -#include "clang/AST/ASTContext.h" -#include "clang/AST/Attr.h" -#include "clang/AST/ParentMap.h" -#include "clang/Analysis/DomainSpecific/CocoaConventions.h" -#include "clang/Basic/SourceManager.h" -#include "clang/Lex/Lexer.h" -#include "clang/Sema/SemaDiagnostic.h" -#include "llvm/ADT/SmallString.h" - -using namespace clang; -using namespace arcmt; -using namespace trans; - -namespace { - -class UnbridgedCastRewriter : public RecursiveASTVisitor<UnbridgedCastRewriter>{ - MigrationPass &Pass; - IdentifierInfo *SelfII; - std::unique_ptr<ParentMap> StmtMap; - Decl *ParentD; - Stmt *Body; - mutable std::unique_ptr<ExprSet> Removables; - -public: - UnbridgedCastRewriter(MigrationPass &pass) - : Pass(pass), ParentD(nullptr), Body(nullptr) { - SelfII = &Pass.Ctx.Idents.get("self"); - } - - void transformBody(Stmt *body, Decl *ParentD) { - this->ParentD = ParentD; - Body = body; - StmtMap.reset(new ParentMap(body)); - TraverseStmt(body); - } - - bool TraverseBlockDecl(BlockDecl *D) { - // ParentMap does not enter into a BlockDecl to record its stmts, so use a - // new UnbridgedCastRewriter to handle the block. - UnbridgedCastRewriter(Pass).transformBody(D->getBody(), D); - return true; - } - - bool VisitCastExpr(CastExpr *E) { - if (E->getCastKind() != CK_CPointerToObjCPointerCast && - E->getCastKind() != CK_BitCast && - E->getCastKind() != CK_AnyPointerToBlockPointerCast) - return true; - - QualType castType = E->getType(); - Expr *castExpr = E->getSubExpr(); - QualType castExprType = castExpr->getType(); - - if (castType->isObjCRetainableType() == castExprType->isObjCRetainableType()) - 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->isObjCRetainableType()) - 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->hasAttr<CFReturnsRetainedAttr>()) { - castToObjCObject(E, /*retained=*/true); - return; - } - if (FD->hasAttr<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) { - // Do not migrate to couple of bridge transfer casts which - // cancel each other out. Leave it unchanged so error gets user - // attention instead. - if (FD->getName() == "CFRetain" && - FD->getNumParams() == 1 && - FD->getParent()->isTranslationUnit() && - FD->isExternallyVisible()) { - Expr *Arg = callE->getArg(0); - if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Arg)) { - const Expr *sub = ICE->getSubExpr(); - QualType T = sub->getType(); - if (T->isObjCObjectPointerType()) - return; - } - } - castToObjCObject(E, /*retained=*/true); - return; - } - - if (fname.find("Get") != StringRef::npos) { - castToObjCObject(E, /*retained=*/false); - return; - } - } - } - } - - // If returning an ivar or a member of an ivar from a +0 method, use - // a __bridge cast. - Expr *base = inner->IgnoreParenImpCasts(); - while (isa<MemberExpr>(base)) - base = cast<MemberExpr>(base)->getBase()->IgnoreParenImpCasts(); - if (isa<ObjCIvarRefExpr>(base) && - isa<ReturnStmt>(StmtMap->getParentIgnoreParenCasts(E))) { - if (ObjCMethodDecl *method = dyn_cast_or_null<ObjCMethodDecl>(ParentD)) { - if (!method->hasAttr<NSReturnsRetainedAttr>()) { - castToObjCObject(E, /*retained=*/false); - return; - } - } - } - } - - void castToObjCObject(CastExpr *E, bool retained) { - rewriteToBridgedCast(E, retained ? OBC_BridgeTransfer : OBC_Bridge); - } - - void rewriteToBridgedCast(CastExpr *E, ObjCBridgeCastKind Kind) { - Transaction Trans(Pass.TA); - rewriteToBridgedCast(E, Kind, Trans); - } - - void rewriteToBridgedCast(CastExpr *E, ObjCBridgeCastKind Kind, - Transaction &Trans) { - 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->getBeginLoc())) { - Trans.abort(); - 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; - } - - TA.clearDiagnostic(diag::err_arc_mismatched_cast, - diag::err_arc_cast_requires_bridge, E->getBeginLoc()); - if (Kind == OBC_Bridge || !Pass.CFBridgingFunctionsDefined()) { - if (CStyleCastExpr *CCE = dyn_cast<CStyleCastExpr>(E)) { - TA.insertAfterToken(CCE->getLParenLoc(), bridge); - } else { - SourceLocation insertLoc = E->getSubExpr()->getBeginLoc(); - SmallString<128> newCast; - newCast += '('; - newCast += bridge; - newCast += E->getType().getAsString(Pass.Ctx.getPrintingPolicy()); - newCast += ')'; - - if (isa<ParenExpr>(E->getSubExpr())) { - TA.insert(insertLoc, newCast.str()); - } else { - newCast += '('; - TA.insert(insertLoc, newCast.str()); - TA.insertAfterToken(E->getEndLoc(), ")"); - } - } - } else { - assert(Kind == OBC_BridgeTransfer || Kind == OBC_BridgeRetained); - SmallString<32> BridgeCall; - - Expr *WrapE = E->getSubExpr(); - SourceLocation InsertLoc = WrapE->getBeginLoc(); - - SourceManager &SM = Pass.Ctx.getSourceManager(); - char PrevChar = *SM.getCharacterData(InsertLoc.getLocWithOffset(-1)); - if (Lexer::isIdentifierBodyChar(PrevChar, Pass.Ctx.getLangOpts())) - BridgeCall += ' '; - - if (Kind == OBC_BridgeTransfer) - BridgeCall += "CFBridgingRelease"; - else - BridgeCall += "CFBridgingRetain"; - - if (isa<ParenExpr>(WrapE)) { - TA.insert(InsertLoc, BridgeCall); - } else { - BridgeCall += '('; - TA.insert(InsertLoc, BridgeCall); - TA.insertAfterToken(WrapE->getEndLoc(), ")"); - } - } - } - - void rewriteCastForCFRetain(CastExpr *castE, CallExpr *callE) { - Transaction Trans(Pass.TA); - Pass.TA.replace(callE->getSourceRange(), callE->getArg(0)->getSourceRange()); - rewriteToBridgedCast(castE, OBC_BridgeRetained, Trans); - } - - void getBlockMacroRanges(CastExpr *E, SourceRange &Outer, SourceRange &Inner) { - SourceManager &SM = Pass.Ctx.getSourceManager(); - SourceLocation Loc = E->getExprLoc(); - assert(Loc.isMacroID()); - CharSourceRange MacroRange = SM.getImmediateExpansionRange(Loc); - SourceRange SubRange = E->getSubExpr()->IgnoreParenImpCasts()->getSourceRange(); - SourceLocation InnerBegin = SM.getImmediateMacroCallerLoc(SubRange.getBegin()); - SourceLocation InnerEnd = SM.getImmediateMacroCallerLoc(SubRange.getEnd()); - - Outer = MacroRange.getAsRange(); - Inner = SourceRange(InnerBegin, InnerEnd); - } - - void rewriteBlockCopyMacro(CastExpr *E) { - SourceRange OuterRange, InnerRange; - getBlockMacroRanges(E, OuterRange, InnerRange); - - Transaction Trans(Pass.TA); - Pass.TA.replace(OuterRange, InnerRange); - Pass.TA.insert(InnerRange.getBegin(), "["); - Pass.TA.insertAfterToken(InnerRange.getEnd(), " copy]"); - Pass.TA.clearDiagnostic(diag::err_arc_mismatched_cast, - diag::err_arc_cast_requires_bridge, - OuterRange); - } - - void removeBlockReleaseMacro(CastExpr *E) { - SourceRange OuterRange, InnerRange; - getBlockMacroRanges(E, OuterRange, InnerRange); - - Transaction Trans(Pass.TA); - Pass.TA.clearDiagnostic(diag::err_arc_mismatched_cast, - diag::err_arc_cast_requires_bridge, - OuterRange); - if (!hasSideEffects(E, Pass.Ctx)) { - if (tryRemoving(cast<Expr>(StmtMap->getParentIgnoreParenCasts(E)))) - return; - } - Pass.TA.replace(OuterRange, InnerRange); - } - - bool tryRemoving(Expr *E) const { - if (!Removables) { - Removables.reset(new ExprSet); - collectRemovables(Body, *Removables); - } - - if (Removables->count(E)) { - Pass.TA.removeStmt(E); - return true; - } - - return false; - } - - void transformObjCToNonObjCCast(CastExpr *E) { - SourceLocation CastLoc = E->getExprLoc(); - if (CastLoc.isMacroID()) { - StringRef MacroName = Lexer::getImmediateMacroName(CastLoc, - Pass.Ctx.getSourceManager(), - Pass.Ctx.getLangOpts()); - if (MacroName == "Block_copy") { - rewriteBlockCopyMacro(E); - return; - } - if (MacroName == "Block_release") { - removeBlockReleaseMacro(E); - return; - } - } - - if (isSelf(E->getSubExpr())) - return rewriteToBridgedCast(E, OBC_Bridge); - - CallExpr *callE; - if (isPassedToCFRetain(E, callE)) - return rewriteCastForCFRetain(E, callE); - - ObjCMethodFamily family = getFamilyOfMessage(E->getSubExpr()); - if (family == OMF_retain) - return rewriteToBridgedCast(E, OBC_BridgeRetained); - - if (family == OMF_autorelease || family == OMF_release) { - std::string err = "it is not safe to cast to '"; - err += E->getType().getAsString(Pass.Ctx.getPrintingPolicy()); - err += "' the result of '"; - err += family == OMF_autorelease ? "autorelease" : "release"; - err += "' message; a __bridge cast may result in a pointer to a " - "destroyed object and a __bridge_retained may leak the object"; - Pass.TA.reportError(err, E->getBeginLoc(), - E->getSubExpr()->getSourceRange()); - Stmt *parent = E; - do { - parent = StmtMap->getParentIgnoreParenImpCasts(parent); - } while (parent && isa<FullExpr>(parent)); - - if (ReturnStmt *retS = dyn_cast_or_null<ReturnStmt>(parent)) { - std::string note = "remove the cast and change return type of function " - "to '"; - note += E->getSubExpr()->getType().getAsString(Pass.Ctx.getPrintingPolicy()); - note += "' to have the object automatically autoreleased"; - Pass.TA.reportNote(note, retS->getBeginLoc()); - } - } - - Expr *subExpr = E->getSubExpr(); - - // Look through pseudo-object expressions. - if (PseudoObjectExpr *pseudo = dyn_cast<PseudoObjectExpr>(subExpr)) { - subExpr = pseudo->getResultExpr(); - assert(subExpr && "no result for pseudo-object of non-void type?"); - } - - if (ImplicitCastExpr *implCE = dyn_cast<ImplicitCastExpr>(subExpr)) { - if (implCE->getCastKind() == CK_ARCConsumeObject) - return rewriteToBridgedCast(E, OBC_BridgeRetained); - if (implCE->getCastKind() == CK_ARCReclaimReturnedObject) - return rewriteToBridgedCast(E, OBC_Bridge); - } - - bool isConsumed = false; - if (isPassedToCParamWithKnownOwnership(E, isConsumed)) - return rewriteToBridgedCast(E, isConsumed ? OBC_BridgeRetained - : OBC_Bridge); - } - - static ObjCMethodFamily getFamilyOfMessage(Expr *E) { - E = E->IgnoreParenCasts(); - if (ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) - return ME->getMethodFamily(); - - return OMF_None; - } - - bool isPassedToCFRetain(Expr *E, CallExpr *&callE) const { - if ((callE = dyn_cast_or_null<CallExpr>( - StmtMap->getParentIgnoreParenImpCasts(E)))) - if (FunctionDecl * - FD = dyn_cast_or_null<FunctionDecl>(callE->getCalleeDecl())) - if (FD->getName() == "CFRetain" && FD->getNumParams() == 1 && - FD->getParent()->isTranslationUnit() && - FD->isExternallyVisible()) - return true; - - return false; - } - - bool isPassedToCParamWithKnownOwnership(Expr *E, bool &isConsumed) const { - if (CallExpr *callE = dyn_cast_or_null<CallExpr>( - StmtMap->getParentIgnoreParenImpCasts(E))) - if (FunctionDecl * - FD = dyn_cast_or_null<FunctionDecl>(callE->getCalleeDecl())) { - unsigned i = 0; - for (unsigned e = callE->getNumArgs(); i != e; ++i) { - Expr *arg = callE->getArg(i); - if (arg == E || arg->IgnoreParenImpCasts() == E) - break; - } - if (i < callE->getNumArgs() && i < FD->getNumParams()) { - ParmVarDecl *PD = FD->getParamDecl(i); - if (PD->hasAttr<CFConsumedAttr>()) { - isConsumed = true; - return true; - } - } - } - - return false; - } - - bool isSelf(Expr *E) const { - E = E->IgnoreParenLValueCasts(); - if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) - if (ImplicitParamDecl *IPD = dyn_cast<ImplicitParamDecl>(DRE->getDecl())) - if (IPD->getIdentifier() == SelfII) - return true; - - return false; - } -}; - -} // end anonymous namespace - -void trans::rewriteUnbridgedCasts(MigrationPass &pass) { - BodyTransform<UnbridgedCastRewriter> trans(pass); - trans.TraverseDecl(pass.Ctx.getTranslationUnitDecl()); -} |