| //===--- Transforms.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 |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "Transforms.h" |
| #include "Internals.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/RecursiveASTVisitor.h" |
| #include "clang/Analysis/DomainSpecific/CocoaConventions.h" |
| #include "clang/Basic/SourceManager.h" |
| #include "clang/Basic/TargetInfo.h" |
| #include "clang/Lex/Lexer.h" |
| #include "clang/Lex/Preprocessor.h" |
| #include "clang/Sema/Sema.h" |
| |
| using namespace clang; |
| using namespace arcmt; |
| using namespace trans; |
| |
| ASTTraverser::~ASTTraverser() { } |
| |
| bool MigrationPass::CFBridgingFunctionsDefined() { |
| if (!EnableCFBridgeFns.hasValue()) |
| EnableCFBridgeFns = SemaRef.isKnownName("CFBridgingRetain") && |
| SemaRef.isKnownName("CFBridgingRelease"); |
| return *EnableCFBridgeFns; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Helpers. |
| //===----------------------------------------------------------------------===// |
| |
| bool trans::canApplyWeak(ASTContext &Ctx, QualType type, |
| bool AllowOnUnknownClass) { |
| if (!Ctx.getLangOpts().ObjCWeakRuntime) |
| return false; |
| |
| QualType T = type; |
| if (T.isNull()) |
| return false; |
| |
| // iOS is always safe to use 'weak'. |
| if (Ctx.getTargetInfo().getTriple().isiOS() || |
| Ctx.getTargetInfo().getTriple().isWatchOS()) |
| 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 && Class->isArcWeakrefUnavailable()) |
| return false; |
| } |
| |
| return true; |
| } |
| |
| bool trans::isPlusOneAssign(const BinaryOperator *E) { |
| if (E->getOpcode() != BO_Assign) |
| return false; |
| |
| return isPlusOne(E->getRHS()); |
| } |
| |
| bool trans::isPlusOne(const Expr *E) { |
| if (!E) |
| return false; |
| if (const FullExpr *FE = dyn_cast<FullExpr>(E)) |
| E = FE->getSubExpr(); |
| |
| if (const ObjCMessageExpr * |
| ME = dyn_cast<ObjCMessageExpr>(E->IgnoreParenCasts())) |
| if (ME->getMethodFamily() == OMF_retain) |
| return true; |
| |
| if (const CallExpr * |
| callE = dyn_cast<CallExpr>(E->IgnoreParenCasts())) { |
| if (const FunctionDecl *FD = callE->getDirectCallee()) { |
| if (FD->hasAttr<CFReturnsRetainedAttr>()) |
| return true; |
| |
| if (FD->isGlobal() && |
| FD->getIdentifier() && |
| FD->getParent()->isTranslationUnit() && |
| FD->isExternallyVisible() && |
| ento::cocoa::isRefType(callE->getType(), "CF", |
| FD->getIdentifier()->getName())) { |
| StringRef fname = FD->getIdentifier()->getName(); |
| if (fname.endswith("Retain") || |
| fname.find("Create") != StringRef::npos || |
| fname.find("Copy") != StringRef::npos) { |
| return true; |
| } |
| } |
| } |
| } |
| |
| const ImplicitCastExpr *implCE = dyn_cast<ImplicitCastExpr>(E); |
| while (implCE && implCE->getCastKind() == CK_BitCast) |
| implCE = dyn_cast<ImplicitCastExpr>(implCE->getSubExpr()); |
| |
| return implCE && implCE->getCastKind() == CK_ARCConsumeObject; |
| } |
| |
| /// '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, bool IsDecl) { |
| SourceLocation SemiLoc = findSemiAfterLocation(loc, Ctx, IsDecl); |
| if (SemiLoc.isInvalid()) |
| return SourceLocation(); |
| return SemiLoc.getLocWithOffset(1); |
| } |
| |
| /// \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, |
| bool IsDecl) { |
| 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)) { |
| if (!IsDecl) |
| return SourceLocation(); |
| // Declaration may be followed with other tokens; such as an __attribute, |
| // before ending with a semicolon. |
| return findSemiAfterLocation(tok.getLocation(), Ctx, /*IsDecl*/true); |
| } |
| |
| 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()->isExternallyVisible(); |
| if (ConditionalOperator *condOp = dyn_cast<ConditionalOperator>(E)) |
| return isGlobalVar(condOp->getTrueExpr()) && |
| isGlobalVar(condOp->getFalseExpr()); |
| |
| return false; |
| } |
| |
| StringRef trans::getNilString(MigrationPass &Pass) { |
| return Pass.SemaRef.PP.isMacroDefined("nil") ? "nil" : "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 (auto *I : S->body()) |
| 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 (auto *Label = dyn_cast<LabelStmt>(S)) |
| S = Label->getSubStmt(); |
| if (auto *E = dyn_cast<Expr>(S)) |
| S = E->IgnoreImplicit(); |
| if (auto *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() == attr::ObjCOwnership) |
| 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 (tok.getRawIdentifier() != "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; |
| if (tok.getRawIdentifier() == 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 (tok.getRawIdentifier() != "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 (const auto *MD : I->instance_methods()) { |
| if (!MD->hasBody()) |
| continue; |
| |
| if (MD->isInstanceMethod() && MD->getSelector() == FinalizeSel) { |
| const 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.addTraverser(new ProtectedScopeTraverser()); |
| |
| 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; |
| } |