1 //== BodyFarm.cpp - Factory for conjuring up fake bodies ----------*- C++ -*-//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // BodyFarm is a factory for creating faux implementations for functions/methods
11 // for analysis purposes.
13 //===----------------------------------------------------------------------===//
15 #include "clang/Analysis/BodyFarm.h"
16 #include "clang/AST/ASTContext.h"
17 #include "clang/AST/CXXInheritance.h"
18 #include "clang/AST/Decl.h"
19 #include "clang/AST/Expr.h"
20 #include "clang/AST/ExprCXX.h"
21 #include "clang/AST/ExprObjC.h"
22 #include "clang/AST/NestedNameSpecifier.h"
23 #include "clang/Analysis/CodeInjector.h"
24 #include "clang/Basic/OperatorKinds.h"
25 #include "llvm/ADT/StringSwitch.h"
26 #include "llvm/Support/Debug.h"
28 #define DEBUG_TYPE "body-farm"
30 using namespace clang;
32 //===----------------------------------------------------------------------===//
33 // Helper creation functions for constructing faux ASTs.
34 //===----------------------------------------------------------------------===//
36 static bool isDispatchBlock(QualType Ty) {
37 // Is it a block pointer?
38 const BlockPointerType *BPT = Ty->getAs<BlockPointerType>();
42 // Check if the block pointer type takes no arguments and
44 const FunctionProtoType *FT =
45 BPT->getPointeeType()->getAs<FunctionProtoType>();
46 return FT && FT->getReturnType()->isVoidType() && FT->getNumParams() == 0;
52 ASTMaker(ASTContext &C) : C(C) {}
54 /// Create a new BinaryOperator representing a simple assignment.
55 BinaryOperator *makeAssignment(const Expr *LHS, const Expr *RHS, QualType Ty);
57 /// Create a new BinaryOperator representing a comparison.
58 BinaryOperator *makeComparison(const Expr *LHS, const Expr *RHS,
59 BinaryOperator::Opcode Op);
61 /// Create a new compound stmt using the provided statements.
62 CompoundStmt *makeCompound(ArrayRef<Stmt*>);
64 /// Create a new DeclRefExpr for the referenced variable.
65 DeclRefExpr *makeDeclRefExpr(const VarDecl *D,
66 bool RefersToEnclosingVariableOrCapture = false);
68 /// Create a new UnaryOperator representing a dereference.
69 UnaryOperator *makeDereference(const Expr *Arg, QualType Ty);
71 /// Create an implicit cast for an integer conversion.
72 Expr *makeIntegralCast(const Expr *Arg, QualType Ty);
74 /// Create an implicit cast to a builtin boolean type.
75 ImplicitCastExpr *makeIntegralCastToBoolean(const Expr *Arg);
77 /// Create an implicit cast for lvalue-to-rvaluate conversions.
78 ImplicitCastExpr *makeLvalueToRvalue(const Expr *Arg, QualType Ty);
80 /// Make RValue out of variable declaration, creating a temporary
81 /// DeclRefExpr in the process.
83 makeLvalueToRvalue(const VarDecl *Decl,
84 bool RefersToEnclosingVariableOrCapture = false);
86 /// Create an implicit cast of the given type.
87 ImplicitCastExpr *makeImplicitCast(const Expr *Arg, QualType Ty,
88 CastKind CK = CK_LValueToRValue);
90 /// Create an Objective-C bool literal.
91 ObjCBoolLiteralExpr *makeObjCBool(bool Val);
93 /// Create an Objective-C ivar reference.
94 ObjCIvarRefExpr *makeObjCIvarRef(const Expr *Base, const ObjCIvarDecl *IVar);
96 /// Create a Return statement.
97 ReturnStmt *makeReturn(const Expr *RetVal);
99 /// Create an integer literal expression of the given type.
100 IntegerLiteral *makeIntegerLiteral(uint64_t Value, QualType Ty);
102 /// Create a member expression.
103 MemberExpr *makeMemberExpression(Expr *base, ValueDecl *MemberDecl,
104 bool IsArrow = false,
105 ExprValueKind ValueKind = VK_LValue);
107 /// Returns a *first* member field of a record declaration with a given name.
108 /// \return an nullptr if no member with such a name exists.
109 ValueDecl *findMemberField(const RecordDecl *RD, StringRef Name);
116 BinaryOperator *ASTMaker::makeAssignment(const Expr *LHS, const Expr *RHS,
118 return new (C) BinaryOperator(const_cast<Expr*>(LHS), const_cast<Expr*>(RHS),
119 BO_Assign, Ty, VK_RValue,
120 OK_Ordinary, SourceLocation(), FPOptions());
123 BinaryOperator *ASTMaker::makeComparison(const Expr *LHS, const Expr *RHS,
124 BinaryOperator::Opcode Op) {
125 assert(BinaryOperator::isLogicalOp(Op) ||
126 BinaryOperator::isComparisonOp(Op));
127 return new (C) BinaryOperator(const_cast<Expr*>(LHS),
128 const_cast<Expr*>(RHS),
130 C.getLogicalOperationType(),
132 OK_Ordinary, SourceLocation(), FPOptions());
135 CompoundStmt *ASTMaker::makeCompound(ArrayRef<Stmt *> Stmts) {
136 return CompoundStmt::Create(C, Stmts, SourceLocation(), SourceLocation());
139 DeclRefExpr *ASTMaker::makeDeclRefExpr(
141 bool RefersToEnclosingVariableOrCapture) {
142 QualType Type = D->getType().getNonReferenceType();
144 DeclRefExpr *DR = DeclRefExpr::Create(
145 C, NestedNameSpecifierLoc(), SourceLocation(), const_cast<VarDecl *>(D),
146 RefersToEnclosingVariableOrCapture, SourceLocation(), Type, VK_LValue);
150 UnaryOperator *ASTMaker::makeDereference(const Expr *Arg, QualType Ty) {
151 return new (C) UnaryOperator(const_cast<Expr*>(Arg), UO_Deref, Ty,
152 VK_LValue, OK_Ordinary, SourceLocation(),
153 /*CanOverflow*/ false);
156 ImplicitCastExpr *ASTMaker::makeLvalueToRvalue(const Expr *Arg, QualType Ty) {
157 return makeImplicitCast(Arg, Ty, CK_LValueToRValue);
161 ASTMaker::makeLvalueToRvalue(const VarDecl *Arg,
162 bool RefersToEnclosingVariableOrCapture) {
163 QualType Type = Arg->getType().getNonReferenceType();
164 return makeLvalueToRvalue(makeDeclRefExpr(Arg,
165 RefersToEnclosingVariableOrCapture),
169 ImplicitCastExpr *ASTMaker::makeImplicitCast(const Expr *Arg, QualType Ty,
171 return ImplicitCastExpr::Create(C, Ty,
173 /* Expr=*/ const_cast<Expr *>(Arg),
174 /* CXXCastPath=*/ nullptr,
175 /* ExprValueKind=*/ VK_RValue);
178 Expr *ASTMaker::makeIntegralCast(const Expr *Arg, QualType Ty) {
179 if (Arg->getType() == Ty)
180 return const_cast<Expr*>(Arg);
182 return ImplicitCastExpr::Create(C, Ty, CK_IntegralCast,
183 const_cast<Expr*>(Arg), nullptr, VK_RValue);
186 ImplicitCastExpr *ASTMaker::makeIntegralCastToBoolean(const Expr *Arg) {
187 return ImplicitCastExpr::Create(C, C.BoolTy, CK_IntegralToBoolean,
188 const_cast<Expr*>(Arg), nullptr, VK_RValue);
191 ObjCBoolLiteralExpr *ASTMaker::makeObjCBool(bool Val) {
192 QualType Ty = C.getBOOLDecl() ? C.getBOOLType() : C.ObjCBuiltinBoolTy;
193 return new (C) ObjCBoolLiteralExpr(Val, Ty, SourceLocation());
196 ObjCIvarRefExpr *ASTMaker::makeObjCIvarRef(const Expr *Base,
197 const ObjCIvarDecl *IVar) {
198 return new (C) ObjCIvarRefExpr(const_cast<ObjCIvarDecl*>(IVar),
199 IVar->getType(), SourceLocation(),
200 SourceLocation(), const_cast<Expr*>(Base),
201 /*arrow=*/true, /*free=*/false);
205 ReturnStmt *ASTMaker::makeReturn(const Expr *RetVal) {
206 return new (C) ReturnStmt(SourceLocation(), const_cast<Expr*>(RetVal),
210 IntegerLiteral *ASTMaker::makeIntegerLiteral(uint64_t Value, QualType Ty) {
211 llvm::APInt APValue = llvm::APInt(C.getTypeSize(Ty), Value);
212 return IntegerLiteral::Create(C, APValue, Ty, SourceLocation());
215 MemberExpr *ASTMaker::makeMemberExpression(Expr *base, ValueDecl *MemberDecl,
217 ExprValueKind ValueKind) {
219 DeclAccessPair FoundDecl = DeclAccessPair::make(MemberDecl, AS_public);
220 return MemberExpr::Create(
221 C, base, IsArrow, SourceLocation(), NestedNameSpecifierLoc(),
222 SourceLocation(), MemberDecl, FoundDecl,
223 DeclarationNameInfo(MemberDecl->getDeclName(), SourceLocation()),
224 /* TemplateArgumentListInfo=*/ nullptr, MemberDecl->getType(), ValueKind,
228 ValueDecl *ASTMaker::findMemberField(const RecordDecl *RD, StringRef Name) {
231 /* FindAmbiguities=*/false,
232 /* RecordPaths=*/false,
233 /* DetectVirtual=*/ false);
234 const IdentifierInfo &II = C.Idents.get(Name);
235 DeclarationName DeclName = C.DeclarationNames.getIdentifier(&II);
237 DeclContextLookupResult Decls = RD->lookup(DeclName);
238 for (NamedDecl *FoundDecl : Decls)
239 if (!FoundDecl->getDeclContext()->isFunctionOrMethod())
240 return cast<ValueDecl>(FoundDecl);
245 //===----------------------------------------------------------------------===//
246 // Creation functions for faux ASTs.
247 //===----------------------------------------------------------------------===//
249 typedef Stmt *(*FunctionFarmer)(ASTContext &C, const FunctionDecl *D);
251 static CallExpr *create_call_once_funcptr_call(ASTContext &C, ASTMaker M,
252 const ParmVarDecl *Callback,
253 ArrayRef<Expr *> CallArgs) {
255 QualType Ty = Callback->getType();
256 DeclRefExpr *Call = M.makeDeclRefExpr(Callback);
258 if (Ty->isRValueReferenceType()) {
259 SubExpr = M.makeImplicitCast(
260 Call, Ty.getNonReferenceType(), CK_LValueToRValue);
261 } else if (Ty->isLValueReferenceType() &&
262 Call->getType()->isFunctionType()) {
263 Ty = C.getPointerType(Ty.getNonReferenceType());
264 SubExpr = M.makeImplicitCast(Call, Ty, CK_FunctionToPointerDecay);
265 } else if (Ty->isLValueReferenceType()
266 && Call->getType()->isPointerType()
267 && Call->getType()->getPointeeType()->isFunctionType()){
270 llvm_unreachable("Unexpected state");
274 CallExpr(C, SubExpr, CallArgs, C.VoidTy, VK_RValue, SourceLocation());
277 static CallExpr *create_call_once_lambda_call(ASTContext &C, ASTMaker M,
278 const ParmVarDecl *Callback,
279 CXXRecordDecl *CallbackDecl,
280 ArrayRef<Expr *> CallArgs) {
281 assert(CallbackDecl != nullptr);
282 assert(CallbackDecl->isLambda());
283 FunctionDecl *callOperatorDecl = CallbackDecl->getLambdaCallOperator();
284 assert(callOperatorDecl != nullptr);
286 DeclRefExpr *callOperatorDeclRef =
287 DeclRefExpr::Create(/* Ctx =*/ C,
288 /* QualifierLoc =*/ NestedNameSpecifierLoc(),
289 /* TemplateKWLoc =*/ SourceLocation(),
290 const_cast<FunctionDecl *>(callOperatorDecl),
291 /* RefersToEnclosingVariableOrCapture=*/ false,
292 /* NameLoc =*/ SourceLocation(),
293 /* T =*/ callOperatorDecl->getType(),
294 /* VK =*/ VK_LValue);
297 CXXOperatorCallExpr(/*AstContext=*/C, OO_Call, callOperatorDeclRef,
299 /*QualType=*/C.VoidTy,
300 /*ExprValueType=*/VK_RValue,
301 /*SourceLocation=*/SourceLocation(), FPOptions());
304 /// Create a fake body for std::call_once.
305 /// Emulates the following function body:
308 /// typedef struct once_flag_s {
309 /// unsigned long __state = 0;
311 /// template<class Callable>
312 /// void call_once(once_flag& o, Callable func) {
313 /// if (!o.__state) {
319 static Stmt *create_call_once(ASTContext &C, const FunctionDecl *D) {
320 LLVM_DEBUG(llvm::dbgs() << "Generating body for call_once\n");
322 // We need at least two parameters.
323 if (D->param_size() < 2)
328 const ParmVarDecl *Flag = D->getParamDecl(0);
329 const ParmVarDecl *Callback = D->getParamDecl(1);
331 if (!Callback->getType()->isReferenceType()) {
332 llvm::dbgs() << "libcxx03 std::call_once implementation, skipping.\n";
335 if (!Flag->getType()->isReferenceType()) {
336 llvm::dbgs() << "unknown std::call_once implementation, skipping.\n";
340 QualType CallbackType = Callback->getType().getNonReferenceType();
342 // Nullable pointer, non-null iff function is a CXXRecordDecl.
343 CXXRecordDecl *CallbackRecordDecl = CallbackType->getAsCXXRecordDecl();
344 QualType FlagType = Flag->getType().getNonReferenceType();
345 auto *FlagRecordDecl = FlagType->getAsRecordDecl();
347 if (!FlagRecordDecl) {
348 LLVM_DEBUG(llvm::dbgs() << "Flag field is not a record: "
349 << "unknown std::call_once implementation, "
350 << "ignoring the call.\n");
354 // We initially assume libc++ implementation of call_once,
355 // where the once_flag struct has a field `__state_`.
356 ValueDecl *FlagFieldDecl = M.findMemberField(FlagRecordDecl, "__state_");
358 // Otherwise, try libstdc++ implementation, with a field
360 if (!FlagFieldDecl) {
361 FlagFieldDecl = M.findMemberField(FlagRecordDecl, "_M_once");
364 if (!FlagFieldDecl) {
365 LLVM_DEBUG(llvm::dbgs() << "No field _M_once or __state_ found on "
366 << "std::once_flag struct: unknown std::call_once "
367 << "implementation, ignoring the call.");
371 bool isLambdaCall = CallbackRecordDecl && CallbackRecordDecl->isLambda();
372 if (CallbackRecordDecl && !isLambdaCall) {
373 LLVM_DEBUG(llvm::dbgs()
374 << "Not supported: synthesizing body for functors when "
375 << "body farming std::call_once, ignoring the call.");
379 SmallVector<Expr *, 5> CallArgs;
380 const FunctionProtoType *CallbackFunctionType;
383 // Lambda requires callback itself inserted as a first parameter.
385 M.makeDeclRefExpr(Callback,
386 /* RefersToEnclosingVariableOrCapture=*/ true));
387 CallbackFunctionType = CallbackRecordDecl->getLambdaCallOperator()
389 ->getAs<FunctionProtoType>();
390 } else if (!CallbackType->getPointeeType().isNull()) {
391 CallbackFunctionType =
392 CallbackType->getPointeeType()->getAs<FunctionProtoType>();
394 CallbackFunctionType = CallbackType->getAs<FunctionProtoType>();
397 if (!CallbackFunctionType)
400 // First two arguments are used for the flag and for the callback.
401 if (D->getNumParams() != CallbackFunctionType->getNumParams() + 2) {
402 LLVM_DEBUG(llvm::dbgs() << "Types of params of the callback do not match "
403 << "params passed to std::call_once, "
404 << "ignoring the call\n");
408 // All arguments past first two ones are passed to the callback,
409 // and we turn lvalues into rvalues if the argument is not passed by
411 for (unsigned int ParamIdx = 2; ParamIdx < D->getNumParams(); ParamIdx++) {
412 const ParmVarDecl *PDecl = D->getParamDecl(ParamIdx);
414 CallbackFunctionType->getParamType(ParamIdx - 2)
415 .getNonReferenceType()
416 .getCanonicalType() !=
417 PDecl->getType().getNonReferenceType().getCanonicalType()) {
418 LLVM_DEBUG(llvm::dbgs() << "Types of params of the callback do not match "
419 << "params passed to std::call_once, "
420 << "ignoring the call\n");
423 Expr *ParamExpr = M.makeDeclRefExpr(PDecl);
424 if (!CallbackFunctionType->getParamType(ParamIdx - 2)->isReferenceType()) {
425 QualType PTy = PDecl->getType().getNonReferenceType();
426 ParamExpr = M.makeLvalueToRvalue(ParamExpr, PTy);
428 CallArgs.push_back(ParamExpr);
431 CallExpr *CallbackCall;
434 CallbackCall = create_call_once_lambda_call(C, M, Callback,
435 CallbackRecordDecl, CallArgs);
438 // Function pointer case.
439 CallbackCall = create_call_once_funcptr_call(C, M, Callback, CallArgs);
442 DeclRefExpr *FlagDecl =
443 M.makeDeclRefExpr(Flag,
444 /* RefersToEnclosingVariableOrCapture=*/true);
447 MemberExpr *Deref = M.makeMemberExpression(FlagDecl, FlagFieldDecl);
448 assert(Deref->isLValue());
449 QualType DerefType = Deref->getType();
451 // Negation predicate.
452 UnaryOperator *FlagCheck = new (C) UnaryOperator(
454 M.makeImplicitCast(M.makeLvalueToRvalue(Deref, DerefType), DerefType,
455 CK_IntegralToBoolean),
457 /* QualType=*/ C.IntTy,
458 /* ExprValueKind=*/ VK_RValue,
459 /* ExprObjectKind=*/ OK_Ordinary, SourceLocation(),
460 /* CanOverflow*/ false);
462 // Create assignment.
463 BinaryOperator *FlagAssignment = M.makeAssignment(
464 Deref, M.makeIntegralCast(M.makeIntegerLiteral(1, C.IntTy), DerefType),
467 IfStmt *Out = new (C)
468 IfStmt(C, SourceLocation(),
469 /* IsConstexpr=*/ false,
472 /* cond=*/ FlagCheck,
473 /* then=*/ M.makeCompound({CallbackCall, FlagAssignment}));
478 /// Create a fake body for dispatch_once.
479 static Stmt *create_dispatch_once(ASTContext &C, const FunctionDecl *D) {
480 // Check if we have at least two parameters.
481 if (D->param_size() != 2)
484 // Check if the first parameter is a pointer to integer type.
485 const ParmVarDecl *Predicate = D->getParamDecl(0);
486 QualType PredicateQPtrTy = Predicate->getType();
487 const PointerType *PredicatePtrTy = PredicateQPtrTy->getAs<PointerType>();
490 QualType PredicateTy = PredicatePtrTy->getPointeeType();
491 if (!PredicateTy->isIntegerType())
494 // Check if the second parameter is the proper block type.
495 const ParmVarDecl *Block = D->getParamDecl(1);
496 QualType Ty = Block->getType();
497 if (!isDispatchBlock(Ty))
500 // Everything checks out. Create a fakse body that checks the predicate,
501 // sets it, and calls the block. Basically, an AST dump of:
503 // void dispatch_once(dispatch_once_t *predicate, dispatch_block_t block) {
504 // if (*predicate != ~0l) {
512 // (1) Create the call.
513 CallExpr *CE = new (C) CallExpr(
515 /*StmtClass=*/M.makeLvalueToRvalue(/*Expr=*/Block),
517 /*QualType=*/C.VoidTy,
518 /*ExprValueType=*/VK_RValue,
519 /*SourceLocation=*/SourceLocation());
521 // (2) Create the assignment to the predicate.
523 new (C) UnaryOperator(M.makeIntegerLiteral(0, C.LongTy), UO_Not, C.LongTy,
524 VK_RValue, OK_Ordinary, SourceLocation(),
525 /*CanOverflow*/false);
530 M.makeLvalueToRvalue(
531 M.makeDeclRefExpr(Predicate), PredicateQPtrTy),
533 M.makeIntegralCast(DoneValue, PredicateTy),
536 // (3) Create the compound statement.
537 Stmt *Stmts[] = { B, CE };
538 CompoundStmt *CS = M.makeCompound(Stmts);
540 // (4) Create the 'if' condition.
541 ImplicitCastExpr *LValToRval =
542 M.makeLvalueToRvalue(
544 M.makeLvalueToRvalue(
545 M.makeDeclRefExpr(Predicate),
550 Expr *GuardCondition = M.makeComparison(LValToRval, DoneValue, BO_NE);
551 // (5) Create the 'if' statement.
552 IfStmt *If = new (C) IfStmt(C, SourceLocation(),
553 /* IsConstexpr=*/ false,
556 /* cond=*/ GuardCondition,
561 /// Create a fake body for dispatch_sync.
562 static Stmt *create_dispatch_sync(ASTContext &C, const FunctionDecl *D) {
563 // Check if we have at least two parameters.
564 if (D->param_size() != 2)
567 // Check if the second parameter is a block.
568 const ParmVarDecl *PV = D->getParamDecl(1);
569 QualType Ty = PV->getType();
570 if (!isDispatchBlock(Ty))
573 // Everything checks out. Create a fake body that just calls the block.
574 // This is basically just an AST dump of:
576 // void dispatch_sync(dispatch_queue_t queue, void (^block)(void)) {
581 DeclRefExpr *DR = M.makeDeclRefExpr(PV);
582 ImplicitCastExpr *ICE = M.makeLvalueToRvalue(DR, Ty);
583 CallExpr *CE = new (C) CallExpr(C, ICE, None, C.VoidTy, VK_RValue,
588 static Stmt *create_OSAtomicCompareAndSwap(ASTContext &C, const FunctionDecl *D)
590 // There are exactly 3 arguments.
591 if (D->param_size() != 3)
595 // _Bool OSAtomicCompareAndSwapPtr(void *__oldValue,
597 // void * volatile *__theValue)
599 // if (oldValue == *theValue) {
600 // *theValue = newValue;
605 QualType ResultTy = D->getReturnType();
606 bool isBoolean = ResultTy->isBooleanType();
607 if (!isBoolean && !ResultTy->isIntegralType(C))
610 const ParmVarDecl *OldValue = D->getParamDecl(0);
611 QualType OldValueTy = OldValue->getType();
613 const ParmVarDecl *NewValue = D->getParamDecl(1);
614 QualType NewValueTy = NewValue->getType();
616 assert(OldValueTy == NewValueTy);
618 const ParmVarDecl *TheValue = D->getParamDecl(2);
619 QualType TheValueTy = TheValue->getType();
620 const PointerType *PT = TheValueTy->getAs<PointerType>();
623 QualType PointeeTy = PT->getPointeeType();
626 // Construct the comparison.
629 M.makeLvalueToRvalue(M.makeDeclRefExpr(OldValue), OldValueTy),
630 M.makeLvalueToRvalue(
632 M.makeLvalueToRvalue(M.makeDeclRefExpr(TheValue), TheValueTy),
637 // Construct the body of the IfStmt.
642 M.makeLvalueToRvalue(M.makeDeclRefExpr(TheValue), TheValueTy),
644 M.makeLvalueToRvalue(M.makeDeclRefExpr(NewValue), NewValueTy),
647 Expr *BoolVal = M.makeObjCBool(true);
648 Expr *RetVal = isBoolean ? M.makeIntegralCastToBoolean(BoolVal)
649 : M.makeIntegralCast(BoolVal, ResultTy);
650 Stmts[1] = M.makeReturn(RetVal);
651 CompoundStmt *Body = M.makeCompound(Stmts);
653 // Construct the else clause.
654 BoolVal = M.makeObjCBool(false);
655 RetVal = isBoolean ? M.makeIntegralCastToBoolean(BoolVal)
656 : M.makeIntegralCast(BoolVal, ResultTy);
657 Stmt *Else = M.makeReturn(RetVal);
659 /// Construct the If.
660 Stmt *If = new (C) IfStmt(C, SourceLocation(), false, nullptr, nullptr,
661 Comparison, Body, SourceLocation(), Else);
666 Stmt *BodyFarm::getBody(const FunctionDecl *D) {
667 D = D->getCanonicalDecl();
669 Optional<Stmt *> &Val = Bodies[D];
671 return Val.getValue();
675 if (D->getIdentifier() == nullptr)
678 StringRef Name = D->getName();
684 if (Name.startswith("OSAtomicCompareAndSwap") ||
685 Name.startswith("objc_atomicCompareAndSwap")) {
686 FF = create_OSAtomicCompareAndSwap;
687 } else if (Name == "call_once" && D->getDeclContext()->isStdNamespace()) {
688 FF = create_call_once;
690 FF = llvm::StringSwitch<FunctionFarmer>(Name)
691 .Case("dispatch_sync", create_dispatch_sync)
692 .Case("dispatch_once", create_dispatch_once)
696 if (FF) { Val = FF(C, D); }
697 else if (Injector) { Val = Injector->getBody(D); }
698 return Val.getValue();
701 static const ObjCIvarDecl *findBackingIvar(const ObjCPropertyDecl *Prop) {
702 const ObjCIvarDecl *IVar = Prop->getPropertyIvarDecl();
707 // When a readonly property is shadowed in a class extensions with a
708 // a readwrite property, the instance variable belongs to the shadowing
709 // property rather than the shadowed property. If there is no instance
710 // variable on a readonly property, check to see whether the property is
711 // shadowed and if so try to get the instance variable from shadowing
713 if (!Prop->isReadOnly())
716 auto *Container = cast<ObjCContainerDecl>(Prop->getDeclContext());
717 const ObjCInterfaceDecl *PrimaryInterface = nullptr;
718 if (auto *InterfaceDecl = dyn_cast<ObjCInterfaceDecl>(Container)) {
719 PrimaryInterface = InterfaceDecl;
720 } else if (auto *CategoryDecl = dyn_cast<ObjCCategoryDecl>(Container)) {
721 PrimaryInterface = CategoryDecl->getClassInterface();
722 } else if (auto *ImplDecl = dyn_cast<ObjCImplDecl>(Container)) {
723 PrimaryInterface = ImplDecl->getClassInterface();
728 // FindPropertyVisibleInPrimaryClass() looks first in class extensions, so it
729 // is guaranteed to find the shadowing property, if it exists, rather than
730 // the shadowed property.
731 auto *ShadowingProp = PrimaryInterface->FindPropertyVisibleInPrimaryClass(
732 Prop->getIdentifier(), Prop->getQueryKind());
733 if (ShadowingProp && ShadowingProp != Prop) {
734 IVar = ShadowingProp->getPropertyIvarDecl();
740 static Stmt *createObjCPropertyGetter(ASTContext &Ctx,
741 const ObjCPropertyDecl *Prop) {
742 // First, find the backing ivar.
743 const ObjCIvarDecl *IVar = findBackingIvar(Prop);
747 // Ignore weak variables, which have special behavior.
748 if (Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_weak)
751 // Look to see if Sema has synthesized a body for us. This happens in
752 // Objective-C++ because the return value may be a C++ class type with a
753 // non-trivial copy constructor. We can only do this if we can find the
754 // @synthesize for this property, though (or if we know it's been auto-
756 const ObjCImplementationDecl *ImplDecl =
757 IVar->getContainingInterface()->getImplementation();
759 for (const auto *I : ImplDecl->property_impls()) {
760 if (I->getPropertyDecl() != Prop)
763 if (I->getGetterCXXConstructor()) {
765 return M.makeReturn(I->getGetterCXXConstructor());
770 // Sanity check that the property is the same type as the ivar, or a
771 // reference to it, and that it is either an object pointer or trivially
773 if (!Ctx.hasSameUnqualifiedType(IVar->getType(),
774 Prop->getType().getNonReferenceType()))
776 if (!IVar->getType()->isObjCLifetimeType() &&
777 !IVar->getType().isTriviallyCopyableType(Ctx))
780 // Generate our body:
781 // return self->_ivar;
784 const VarDecl *selfVar = Prop->getGetterMethodDecl()->getSelfDecl();
790 M.makeLvalueToRvalue(
791 M.makeDeclRefExpr(selfVar),
795 if (!Prop->getType()->isReferenceType())
796 loadedIVar = M.makeLvalueToRvalue(loadedIVar, IVar->getType());
798 return M.makeReturn(loadedIVar);
801 Stmt *BodyFarm::getBody(const ObjCMethodDecl *D) {
802 // We currently only know how to synthesize property accessors.
803 if (!D->isPropertyAccessor())
806 D = D->getCanonicalDecl();
808 Optional<Stmt *> &Val = Bodies[D];
810 return Val.getValue();
813 const ObjCPropertyDecl *Prop = D->findPropertyDecl();
817 // For now, we only synthesize getters.
818 // Synthesizing setters would cause false negatives in the
819 // RetainCountChecker because the method body would bind the parameter
820 // to an instance variable, causing it to escape. This would prevent
821 // warning in the following common scenario:
823 // id foo = [[NSObject alloc] init];
824 // self.foo = foo; // We should warn that foo leaks here.
826 if (D->param_size() != 0)
829 Val = createObjCPropertyGetter(C, Prop);
831 return Val.getValue();