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path: root/lib/ARCMigrate/TransRetainReleaseDealloc.cpp
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Diffstat (limited to 'lib/ARCMigrate/TransRetainReleaseDealloc.cpp')
-rw-r--r--lib/ARCMigrate/TransRetainReleaseDealloc.cpp459
1 files changed, 0 insertions, 459 deletions
diff --git a/lib/ARCMigrate/TransRetainReleaseDealloc.cpp b/lib/ARCMigrate/TransRetainReleaseDealloc.cpp
deleted file mode 100644
index b76fc65574dd4..0000000000000
--- a/lib/ARCMigrate/TransRetainReleaseDealloc.cpp
+++ /dev/null
@@ -1,459 +0,0 @@
-//===--- TransRetainReleaseDealloc.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
-//
-//===----------------------------------------------------------------------===//
-//
-// removeRetainReleaseDealloc:
-//
-// Removes retain/release/autorelease/dealloc messages.
-//
-// return [[foo retain] autorelease];
-// ---->
-// return foo;
-//
-//===----------------------------------------------------------------------===//
-
-#include "Transforms.h"
-#include "Internals.h"
-#include "clang/AST/ASTContext.h"
-#include "clang/AST/ParentMap.h"
-#include "clang/Basic/SourceManager.h"
-#include "clang/Lex/Lexer.h"
-#include "clang/Sema/SemaDiagnostic.h"
-#include "llvm/ADT/StringSwitch.h"
-
-using namespace clang;
-using namespace arcmt;
-using namespace trans;
-
-namespace {
-
-class RetainReleaseDeallocRemover :
- public RecursiveASTVisitor<RetainReleaseDeallocRemover> {
- Stmt *Body;
- MigrationPass &Pass;
-
- ExprSet Removables;
- std::unique_ptr<ParentMap> StmtMap;
-
- Selector DelegateSel, FinalizeSel;
-
-public:
- RetainReleaseDeallocRemover(MigrationPass &pass)
- : Body(nullptr), Pass(pass) {
- DelegateSel =
- Pass.Ctx.Selectors.getNullarySelector(&Pass.Ctx.Idents.get("delegate"));
- FinalizeSel =
- Pass.Ctx.Selectors.getNullarySelector(&Pass.Ctx.Idents.get("finalize"));
- }
-
- void transformBody(Stmt *body, Decl *ParentD) {
- Body = body;
- collectRemovables(body, Removables);
- StmtMap.reset(new ParentMap(body));
- TraverseStmt(body);
- }
-
- bool VisitObjCMessageExpr(ObjCMessageExpr *E) {
- switch (E->getMethodFamily()) {
- default:
- if (E->isInstanceMessage() && E->getSelector() == FinalizeSel)
- break;
- return true;
- case OMF_autorelease:
- if (isRemovable(E)) {
- if (!isCommonUnusedAutorelease(E)) {
- // An unused autorelease is badness. If we remove it the receiver
- // will likely die immediately while previously it was kept alive
- // by the autorelease pool. This is bad practice in general, leave it
- // and emit an error to force the user to restructure their code.
- Pass.TA.reportError(
- "it is not safe to remove an unused 'autorelease' "
- "message; its receiver may be destroyed immediately",
- E->getBeginLoc(), E->getSourceRange());
- return true;
- }
- }
- // Pass through.
- LLVM_FALLTHROUGH;
- case OMF_retain:
- case OMF_release:
- if (E->getReceiverKind() == ObjCMessageExpr::Instance)
- if (Expr *rec = E->getInstanceReceiver()) {
- rec = rec->IgnoreParenImpCasts();
- if (rec->getType().getObjCLifetime() == Qualifiers::OCL_ExplicitNone &&
- (E->getMethodFamily() != OMF_retain || isRemovable(E))) {
- std::string err = "it is not safe to remove '";
- err += E->getSelector().getAsString() + "' message on "
- "an __unsafe_unretained type";
- Pass.TA.reportError(err, rec->getBeginLoc());
- return true;
- }
-
- if (isGlobalVar(rec) &&
- (E->getMethodFamily() != OMF_retain || isRemovable(E))) {
- std::string err = "it is not safe to remove '";
- err += E->getSelector().getAsString() + "' message on "
- "a global variable";
- Pass.TA.reportError(err, rec->getBeginLoc());
- return true;
- }
-
- if (E->getMethodFamily() == OMF_release && isDelegateMessage(rec)) {
- Pass.TA.reportError(
- "it is not safe to remove 'retain' "
- "message on the result of a 'delegate' message; "
- "the object that was passed to 'setDelegate:' may not be "
- "properly retained",
- rec->getBeginLoc());
- return true;
- }
- }
- break;
- case OMF_dealloc:
- break;
- }
-
- switch (E->getReceiverKind()) {
- default:
- return true;
- case ObjCMessageExpr::SuperInstance: {
- Transaction Trans(Pass.TA);
- clearDiagnostics(E->getSelectorLoc(0));
- if (tryRemoving(E))
- return true;
- Pass.TA.replace(E->getSourceRange(), "self");
- return true;
- }
- case ObjCMessageExpr::Instance:
- break;
- }
-
- Expr *rec = E->getInstanceReceiver();
- if (!rec) return true;
-
- Transaction Trans(Pass.TA);
- clearDiagnostics(E->getSelectorLoc(0));
-
- ObjCMessageExpr *Msg = E;
- Expr *RecContainer = Msg;
- SourceRange RecRange = rec->getSourceRange();
- checkForGCDOrXPC(Msg, RecContainer, rec, RecRange);
-
- if (Msg->getMethodFamily() == OMF_release &&
- isRemovable(RecContainer) && isInAtFinally(RecContainer)) {
- // Change the -release to "receiver = nil" in a finally to avoid a leak
- // when an exception is thrown.
- Pass.TA.replace(RecContainer->getSourceRange(), RecRange);
- std::string str = " = ";
- str += getNilString(Pass);
- Pass.TA.insertAfterToken(RecRange.getEnd(), str);
- return true;
- }
-
- if (hasSideEffects(rec, Pass.Ctx) || !tryRemoving(RecContainer))
- Pass.TA.replace(RecContainer->getSourceRange(), RecRange);
-
- return true;
- }
-
-private:
- /// Checks for idioms where an unused -autorelease is common.
- ///
- /// Returns true for this idiom which is common in property
- /// setters:
- ///
- /// [backingValue autorelease];
- /// backingValue = [newValue retain]; // in general a +1 assign
- ///
- /// For these as well:
- ///
- /// [[var retain] autorelease];
- /// return var;
- ///
- bool isCommonUnusedAutorelease(ObjCMessageExpr *E) {
- return isPlusOneAssignBeforeOrAfterAutorelease(E) ||
- isReturnedAfterAutorelease(E);
- }
-
- bool isReturnedAfterAutorelease(ObjCMessageExpr *E) {
- Expr *Rec = E->getInstanceReceiver();
- if (!Rec)
- return false;
-
- Decl *RefD = getReferencedDecl(Rec);
- if (!RefD)
- return false;
-
- Stmt *nextStmt = getNextStmt(E);
- if (!nextStmt)
- return false;
-
- // Check for "return <variable>;".
-
- if (ReturnStmt *RetS = dyn_cast<ReturnStmt>(nextStmt))
- return RefD == getReferencedDecl(RetS->getRetValue());
-
- return false;
- }
-
- bool isPlusOneAssignBeforeOrAfterAutorelease(ObjCMessageExpr *E) {
- Expr *Rec = E->getInstanceReceiver();
- if (!Rec)
- return false;
-
- Decl *RefD = getReferencedDecl(Rec);
- if (!RefD)
- return false;
-
- Stmt *prevStmt, *nextStmt;
- std::tie(prevStmt, nextStmt) = getPreviousAndNextStmt(E);
-
- return isPlusOneAssignToVar(prevStmt, RefD) ||
- isPlusOneAssignToVar(nextStmt, RefD);
- }
-
- bool isPlusOneAssignToVar(Stmt *S, Decl *RefD) {
- if (!S)
- return false;
-
- // Check for "RefD = [+1 retained object];".
-
- if (BinaryOperator *Bop = dyn_cast<BinaryOperator>(S)) {
- return (RefD == getReferencedDecl(Bop->getLHS())) && isPlusOneAssign(Bop);
- }
-
- if (DeclStmt *DS = dyn_cast<DeclStmt>(S)) {
- if (DS->isSingleDecl() && DS->getSingleDecl() == RefD) {
- if (VarDecl *VD = dyn_cast<VarDecl>(RefD))
- return isPlusOne(VD->getInit());
- }
- return false;
- }
-
- return false;
- }
-
- Stmt *getNextStmt(Expr *E) {
- return getPreviousAndNextStmt(E).second;
- }
-
- std::pair<Stmt *, Stmt *> getPreviousAndNextStmt(Expr *E) {
- Stmt *prevStmt = nullptr, *nextStmt = nullptr;
- if (!E)
- return std::make_pair(prevStmt, nextStmt);
-
- Stmt *OuterS = E, *InnerS;
- do {
- InnerS = OuterS;
- OuterS = StmtMap->getParent(InnerS);
- }
- while (OuterS && (isa<ParenExpr>(OuterS) ||
- isa<CastExpr>(OuterS) ||
- isa<FullExpr>(OuterS)));
-
- if (!OuterS)
- return std::make_pair(prevStmt, nextStmt);
-
- Stmt::child_iterator currChildS = OuterS->child_begin();
- Stmt::child_iterator childE = OuterS->child_end();
- Stmt::child_iterator prevChildS = childE;
- for (; currChildS != childE; ++currChildS) {
- if (*currChildS == InnerS)
- break;
- prevChildS = currChildS;
- }
-
- if (prevChildS != childE) {
- prevStmt = *prevChildS;
- if (auto *E = dyn_cast_or_null<Expr>(prevStmt))
- prevStmt = E->IgnoreImplicit();
- }
-
- if (currChildS == childE)
- return std::make_pair(prevStmt, nextStmt);
- ++currChildS;
- if (currChildS == childE)
- return std::make_pair(prevStmt, nextStmt);
-
- nextStmt = *currChildS;
- if (auto *E = dyn_cast_or_null<Expr>(nextStmt))
- nextStmt = E->IgnoreImplicit();
-
- return std::make_pair(prevStmt, nextStmt);
- }
-
- Decl *getReferencedDecl(Expr *E) {
- if (!E)
- return nullptr;
-
- E = E->IgnoreParenCasts();
- if (ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) {
- switch (ME->getMethodFamily()) {
- case OMF_copy:
- case OMF_autorelease:
- case OMF_release:
- case OMF_retain:
- return getReferencedDecl(ME->getInstanceReceiver());
- default:
- return nullptr;
- }
- }
- if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
- return DRE->getDecl();
- if (MemberExpr *ME = dyn_cast<MemberExpr>(E))
- return ME->getMemberDecl();
- if (ObjCIvarRefExpr *IRE = dyn_cast<ObjCIvarRefExpr>(E))
- return IRE->getDecl();
-
- return nullptr;
- }
-
- /// Check if the retain/release is due to a GCD/XPC macro that are
- /// defined as:
- ///
- /// #define dispatch_retain(object) ({ dispatch_object_t _o = (object); _dispatch_object_validate(_o); (void)[_o retain]; })
- /// #define dispatch_release(object) ({ dispatch_object_t _o = (object); _dispatch_object_validate(_o); [_o release]; })
- /// #define xpc_retain(object) ({ xpc_object_t _o = (object); _xpc_object_validate(_o); [_o retain]; })
- /// #define xpc_release(object) ({ xpc_object_t _o = (object); _xpc_object_validate(_o); [_o release]; })
- ///
- /// and return the top container which is the StmtExpr and the macro argument
- /// expression.
- void checkForGCDOrXPC(ObjCMessageExpr *Msg, Expr *&RecContainer,
- Expr *&Rec, SourceRange &RecRange) {
- SourceLocation Loc = Msg->getExprLoc();
- if (!Loc.isMacroID())
- return;
- SourceManager &SM = Pass.Ctx.getSourceManager();
- StringRef MacroName = Lexer::getImmediateMacroName(Loc, SM,
- Pass.Ctx.getLangOpts());
- bool isGCDOrXPC = llvm::StringSwitch<bool>(MacroName)
- .Case("dispatch_retain", true)
- .Case("dispatch_release", true)
- .Case("xpc_retain", true)
- .Case("xpc_release", true)
- .Default(false);
- if (!isGCDOrXPC)
- return;
-
- StmtExpr *StmtE = nullptr;
- Stmt *S = Msg;
- while (S) {
- if (StmtExpr *SE = dyn_cast<StmtExpr>(S)) {
- StmtE = SE;
- break;
- }
- S = StmtMap->getParent(S);
- }
-
- if (!StmtE)
- return;
-
- Stmt::child_range StmtExprChild = StmtE->children();
- if (StmtExprChild.begin() == StmtExprChild.end())
- return;
- auto *CompS = dyn_cast_or_null<CompoundStmt>(*StmtExprChild.begin());
- if (!CompS)
- return;
-
- Stmt::child_range CompStmtChild = CompS->children();
- if (CompStmtChild.begin() == CompStmtChild.end())
- return;
- auto *DeclS = dyn_cast_or_null<DeclStmt>(*CompStmtChild.begin());
- if (!DeclS)
- return;
- if (!DeclS->isSingleDecl())
- return;
- VarDecl *VD = dyn_cast_or_null<VarDecl>(DeclS->getSingleDecl());
- if (!VD)
- return;
- Expr *Init = VD->getInit();
- if (!Init)
- return;
-
- RecContainer = StmtE;
- Rec = Init->IgnoreParenImpCasts();
- if (FullExpr *FE = dyn_cast<FullExpr>(Rec))
- Rec = FE->getSubExpr()->IgnoreParenImpCasts();
- RecRange = Rec->getSourceRange();
- if (SM.isMacroArgExpansion(RecRange.getBegin()))
- RecRange.setBegin(SM.getImmediateSpellingLoc(RecRange.getBegin()));
- if (SM.isMacroArgExpansion(RecRange.getEnd()))
- RecRange.setEnd(SM.getImmediateSpellingLoc(RecRange.getEnd()));
- }
-
- void clearDiagnostics(SourceLocation loc) const {
- Pass.TA.clearDiagnostic(diag::err_arc_illegal_explicit_message,
- diag::err_unavailable,
- diag::err_unavailable_message,
- loc);
- }
-
- bool isDelegateMessage(Expr *E) const {
- if (!E) return false;
-
- E = E->IgnoreParenCasts();
-
- // Also look through property-getter sugar.
- if (PseudoObjectExpr *pseudoOp = dyn_cast<PseudoObjectExpr>(E))
- E = pseudoOp->getResultExpr()->IgnoreImplicit();
-
- if (ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E))
- return (ME->isInstanceMessage() && ME->getSelector() == DelegateSel);
-
- return false;
- }
-
- bool isInAtFinally(Expr *E) const {
- assert(E);
- Stmt *S = E;
- while (S) {
- if (isa<ObjCAtFinallyStmt>(S))
- return true;
- S = StmtMap->getParent(S);
- }
-
- return false;
- }
-
- bool isRemovable(Expr *E) const {
- return Removables.count(E);
- }
-
- bool tryRemoving(Expr *E) const {
- if (isRemovable(E)) {
- Pass.TA.removeStmt(E);
- return true;
- }
-
- Stmt *parent = StmtMap->getParent(E);
-
- if (ImplicitCastExpr *castE = dyn_cast_or_null<ImplicitCastExpr>(parent))
- return tryRemoving(castE);
-
- if (ParenExpr *parenE = dyn_cast_or_null<ParenExpr>(parent))
- return tryRemoving(parenE);
-
- if (BinaryOperator *
- bopE = dyn_cast_or_null<BinaryOperator>(parent)) {
- if (bopE->getOpcode() == BO_Comma && bopE->getLHS() == E &&
- isRemovable(bopE)) {
- Pass.TA.replace(bopE->getSourceRange(), bopE->getRHS()->getSourceRange());
- return true;
- }
- }
-
- return false;
- }
-
-};
-
-} // anonymous namespace
-
-void trans::removeRetainReleaseDeallocFinalize(MigrationPass &pass) {
- BodyTransform<RetainReleaseDeallocRemover> trans(pass);
- trans.TraverseDecl(pass.Ctx.getTranslationUnitDecl());
-}
generated by cgit v1.2.3 (git 2.25.1) at 2025-11-04 11:24:16 +0000