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866 lines
30 KiB
866 lines
30 KiB
//== BodyFarm.cpp - Factory for conjuring up fake bodies ----------*- C++ -*-//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// BodyFarm is a factory for creating faux implementations for functions/methods
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// for analysis purposes.
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//
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//===----------------------------------------------------------------------===//
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#include "clang/Analysis/BodyFarm.h"
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#include "clang/AST/ASTContext.h"
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#include "clang/AST/CXXInheritance.h"
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#include "clang/AST/Decl.h"
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#include "clang/AST/Expr.h"
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#include "clang/AST/ExprCXX.h"
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#include "clang/AST/ExprObjC.h"
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#include "clang/AST/NestedNameSpecifier.h"
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#include "clang/Analysis/CodeInjector.h"
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#include "clang/Basic/OperatorKinds.h"
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#include "llvm/ADT/StringSwitch.h"
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#include "llvm/Support/Debug.h"
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#define DEBUG_TYPE "body-farm"
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using namespace clang;
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//===----------------------------------------------------------------------===//
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// Helper creation functions for constructing faux ASTs.
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//===----------------------------------------------------------------------===//
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static bool isDispatchBlock(QualType Ty) {
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// Is it a block pointer?
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const BlockPointerType *BPT = Ty->getAs<BlockPointerType>();
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if (!BPT)
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return false;
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// Check if the block pointer type takes no arguments and
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// returns void.
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const FunctionProtoType *FT =
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BPT->getPointeeType()->getAs<FunctionProtoType>();
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return FT && FT->getReturnType()->isVoidType() && FT->getNumParams() == 0;
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}
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namespace {
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class ASTMaker {
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public:
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ASTMaker(ASTContext &C) : C(C) {}
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/// Create a new BinaryOperator representing a simple assignment.
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BinaryOperator *makeAssignment(const Expr *LHS, const Expr *RHS, QualType Ty);
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/// Create a new BinaryOperator representing a comparison.
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BinaryOperator *makeComparison(const Expr *LHS, const Expr *RHS,
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BinaryOperator::Opcode Op);
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/// Create a new compound stmt using the provided statements.
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CompoundStmt *makeCompound(ArrayRef<Stmt*>);
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/// Create a new DeclRefExpr for the referenced variable.
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DeclRefExpr *makeDeclRefExpr(const VarDecl *D,
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bool RefersToEnclosingVariableOrCapture = false);
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/// Create a new UnaryOperator representing a dereference.
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UnaryOperator *makeDereference(const Expr *Arg, QualType Ty);
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/// Create an implicit cast for an integer conversion.
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Expr *makeIntegralCast(const Expr *Arg, QualType Ty);
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/// Create an implicit cast to a builtin boolean type.
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ImplicitCastExpr *makeIntegralCastToBoolean(const Expr *Arg);
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/// Create an implicit cast for lvalue-to-rvaluate conversions.
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ImplicitCastExpr *makeLvalueToRvalue(const Expr *Arg, QualType Ty);
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/// Make RValue out of variable declaration, creating a temporary
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/// DeclRefExpr in the process.
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ImplicitCastExpr *
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makeLvalueToRvalue(const VarDecl *Decl,
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bool RefersToEnclosingVariableOrCapture = false);
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/// Create an implicit cast of the given type.
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ImplicitCastExpr *makeImplicitCast(const Expr *Arg, QualType Ty,
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CastKind CK = CK_LValueToRValue);
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/// Create an Objective-C bool literal.
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ObjCBoolLiteralExpr *makeObjCBool(bool Val);
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/// Create an Objective-C ivar reference.
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ObjCIvarRefExpr *makeObjCIvarRef(const Expr *Base, const ObjCIvarDecl *IVar);
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/// Create a Return statement.
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ReturnStmt *makeReturn(const Expr *RetVal);
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/// Create an integer literal expression of the given type.
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IntegerLiteral *makeIntegerLiteral(uint64_t Value, QualType Ty);
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/// Create a member expression.
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MemberExpr *makeMemberExpression(Expr *base, ValueDecl *MemberDecl,
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bool IsArrow = false,
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ExprValueKind ValueKind = VK_LValue);
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/// Returns a *first* member field of a record declaration with a given name.
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/// \return an nullptr if no member with such a name exists.
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ValueDecl *findMemberField(const RecordDecl *RD, StringRef Name);
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private:
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ASTContext &C;
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};
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}
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BinaryOperator *ASTMaker::makeAssignment(const Expr *LHS, const Expr *RHS,
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QualType Ty) {
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return BinaryOperator::Create(
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C, const_cast<Expr *>(LHS), const_cast<Expr *>(RHS), BO_Assign, Ty,
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VK_RValue, OK_Ordinary, SourceLocation(), FPOptionsOverride());
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}
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BinaryOperator *ASTMaker::makeComparison(const Expr *LHS, const Expr *RHS,
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BinaryOperator::Opcode Op) {
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assert(BinaryOperator::isLogicalOp(Op) ||
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BinaryOperator::isComparisonOp(Op));
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return BinaryOperator::Create(
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C, const_cast<Expr *>(LHS), const_cast<Expr *>(RHS), Op,
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C.getLogicalOperationType(), VK_RValue, OK_Ordinary, SourceLocation(),
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FPOptionsOverride());
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}
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CompoundStmt *ASTMaker::makeCompound(ArrayRef<Stmt *> Stmts) {
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return CompoundStmt::Create(C, Stmts, SourceLocation(), SourceLocation());
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}
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DeclRefExpr *ASTMaker::makeDeclRefExpr(
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const VarDecl *D,
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bool RefersToEnclosingVariableOrCapture) {
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QualType Type = D->getType().getNonReferenceType();
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DeclRefExpr *DR = DeclRefExpr::Create(
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C, NestedNameSpecifierLoc(), SourceLocation(), const_cast<VarDecl *>(D),
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RefersToEnclosingVariableOrCapture, SourceLocation(), Type, VK_LValue);
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return DR;
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}
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UnaryOperator *ASTMaker::makeDereference(const Expr *Arg, QualType Ty) {
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return UnaryOperator::Create(C, const_cast<Expr *>(Arg), UO_Deref, Ty,
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VK_LValue, OK_Ordinary, SourceLocation(),
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/*CanOverflow*/ false, FPOptionsOverride());
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}
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ImplicitCastExpr *ASTMaker::makeLvalueToRvalue(const Expr *Arg, QualType Ty) {
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return makeImplicitCast(Arg, Ty, CK_LValueToRValue);
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}
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ImplicitCastExpr *
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ASTMaker::makeLvalueToRvalue(const VarDecl *Arg,
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bool RefersToEnclosingVariableOrCapture) {
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QualType Type = Arg->getType().getNonReferenceType();
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return makeLvalueToRvalue(makeDeclRefExpr(Arg,
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RefersToEnclosingVariableOrCapture),
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Type);
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}
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ImplicitCastExpr *ASTMaker::makeImplicitCast(const Expr *Arg, QualType Ty,
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CastKind CK) {
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return ImplicitCastExpr::Create(C, Ty,
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/* CastKind=*/CK,
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/* Expr=*/const_cast<Expr *>(Arg),
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/* CXXCastPath=*/nullptr,
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/* ExprValueKind=*/VK_RValue,
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/* FPFeatures */ FPOptionsOverride());
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}
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Expr *ASTMaker::makeIntegralCast(const Expr *Arg, QualType Ty) {
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if (Arg->getType() == Ty)
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return const_cast<Expr*>(Arg);
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return makeImplicitCast(Arg, Ty, CK_IntegralCast);
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}
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ImplicitCastExpr *ASTMaker::makeIntegralCastToBoolean(const Expr *Arg) {
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return makeImplicitCast(Arg, C.BoolTy, CK_IntegralToBoolean);
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}
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ObjCBoolLiteralExpr *ASTMaker::makeObjCBool(bool Val) {
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QualType Ty = C.getBOOLDecl() ? C.getBOOLType() : C.ObjCBuiltinBoolTy;
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return new (C) ObjCBoolLiteralExpr(Val, Ty, SourceLocation());
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}
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ObjCIvarRefExpr *ASTMaker::makeObjCIvarRef(const Expr *Base,
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const ObjCIvarDecl *IVar) {
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return new (C) ObjCIvarRefExpr(const_cast<ObjCIvarDecl*>(IVar),
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IVar->getType(), SourceLocation(),
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SourceLocation(), const_cast<Expr*>(Base),
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/*arrow=*/true, /*free=*/false);
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}
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ReturnStmt *ASTMaker::makeReturn(const Expr *RetVal) {
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return ReturnStmt::Create(C, SourceLocation(), const_cast<Expr *>(RetVal),
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/* NRVOCandidate=*/nullptr);
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}
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IntegerLiteral *ASTMaker::makeIntegerLiteral(uint64_t Value, QualType Ty) {
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llvm::APInt APValue = llvm::APInt(C.getTypeSize(Ty), Value);
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return IntegerLiteral::Create(C, APValue, Ty, SourceLocation());
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}
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MemberExpr *ASTMaker::makeMemberExpression(Expr *base, ValueDecl *MemberDecl,
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bool IsArrow,
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ExprValueKind ValueKind) {
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DeclAccessPair FoundDecl = DeclAccessPair::make(MemberDecl, AS_public);
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return MemberExpr::Create(
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C, base, IsArrow, SourceLocation(), NestedNameSpecifierLoc(),
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SourceLocation(), MemberDecl, FoundDecl,
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DeclarationNameInfo(MemberDecl->getDeclName(), SourceLocation()),
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/* TemplateArgumentListInfo=*/ nullptr, MemberDecl->getType(), ValueKind,
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OK_Ordinary, NOUR_None);
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}
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ValueDecl *ASTMaker::findMemberField(const RecordDecl *RD, StringRef Name) {
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CXXBasePaths Paths(
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/* FindAmbiguities=*/false,
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/* RecordPaths=*/false,
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/* DetectVirtual=*/ false);
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const IdentifierInfo &II = C.Idents.get(Name);
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DeclarationName DeclName = C.DeclarationNames.getIdentifier(&II);
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DeclContextLookupResult Decls = RD->lookup(DeclName);
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for (NamedDecl *FoundDecl : Decls)
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if (!FoundDecl->getDeclContext()->isFunctionOrMethod())
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return cast<ValueDecl>(FoundDecl);
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return nullptr;
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}
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//===----------------------------------------------------------------------===//
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// Creation functions for faux ASTs.
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//===----------------------------------------------------------------------===//
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typedef Stmt *(*FunctionFarmer)(ASTContext &C, const FunctionDecl *D);
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static CallExpr *create_call_once_funcptr_call(ASTContext &C, ASTMaker M,
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const ParmVarDecl *Callback,
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ArrayRef<Expr *> CallArgs) {
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QualType Ty = Callback->getType();
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DeclRefExpr *Call = M.makeDeclRefExpr(Callback);
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Expr *SubExpr;
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if (Ty->isRValueReferenceType()) {
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SubExpr = M.makeImplicitCast(
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Call, Ty.getNonReferenceType(), CK_LValueToRValue);
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} else if (Ty->isLValueReferenceType() &&
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Call->getType()->isFunctionType()) {
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Ty = C.getPointerType(Ty.getNonReferenceType());
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SubExpr = M.makeImplicitCast(Call, Ty, CK_FunctionToPointerDecay);
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} else if (Ty->isLValueReferenceType()
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&& Call->getType()->isPointerType()
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&& Call->getType()->getPointeeType()->isFunctionType()){
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SubExpr = Call;
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} else {
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llvm_unreachable("Unexpected state");
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}
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return CallExpr::Create(C, SubExpr, CallArgs, C.VoidTy, VK_RValue,
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SourceLocation(), FPOptionsOverride());
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}
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static CallExpr *create_call_once_lambda_call(ASTContext &C, ASTMaker M,
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const ParmVarDecl *Callback,
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CXXRecordDecl *CallbackDecl,
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ArrayRef<Expr *> CallArgs) {
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assert(CallbackDecl != nullptr);
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assert(CallbackDecl->isLambda());
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FunctionDecl *callOperatorDecl = CallbackDecl->getLambdaCallOperator();
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assert(callOperatorDecl != nullptr);
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DeclRefExpr *callOperatorDeclRef =
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DeclRefExpr::Create(/* Ctx =*/ C,
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/* QualifierLoc =*/ NestedNameSpecifierLoc(),
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/* TemplateKWLoc =*/ SourceLocation(),
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const_cast<FunctionDecl *>(callOperatorDecl),
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/* RefersToEnclosingVariableOrCapture=*/ false,
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/* NameLoc =*/ SourceLocation(),
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/* T =*/ callOperatorDecl->getType(),
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/* VK =*/ VK_LValue);
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return CXXOperatorCallExpr::Create(
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/*AstContext=*/C, OO_Call, callOperatorDeclRef,
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/*Args=*/CallArgs,
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/*QualType=*/C.VoidTy,
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/*ExprValueType=*/VK_RValue,
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/*SourceLocation=*/SourceLocation(),
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/*FPFeatures=*/FPOptionsOverride());
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}
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/// Create a fake body for std::call_once.
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/// Emulates the following function body:
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///
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/// \code
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/// typedef struct once_flag_s {
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/// unsigned long __state = 0;
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/// } once_flag;
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/// template<class Callable>
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/// void call_once(once_flag& o, Callable func) {
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/// if (!o.__state) {
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/// func();
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/// }
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/// o.__state = 1;
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/// }
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/// \endcode
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static Stmt *create_call_once(ASTContext &C, const FunctionDecl *D) {
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LLVM_DEBUG(llvm::dbgs() << "Generating body for call_once\n");
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// We need at least two parameters.
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if (D->param_size() < 2)
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return nullptr;
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ASTMaker M(C);
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const ParmVarDecl *Flag = D->getParamDecl(0);
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const ParmVarDecl *Callback = D->getParamDecl(1);
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if (!Callback->getType()->isReferenceType()) {
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llvm::dbgs() << "libcxx03 std::call_once implementation, skipping.\n";
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return nullptr;
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}
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if (!Flag->getType()->isReferenceType()) {
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llvm::dbgs() << "unknown std::call_once implementation, skipping.\n";
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return nullptr;
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}
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QualType CallbackType = Callback->getType().getNonReferenceType();
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// Nullable pointer, non-null iff function is a CXXRecordDecl.
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CXXRecordDecl *CallbackRecordDecl = CallbackType->getAsCXXRecordDecl();
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QualType FlagType = Flag->getType().getNonReferenceType();
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auto *FlagRecordDecl = FlagType->getAsRecordDecl();
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if (!FlagRecordDecl) {
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LLVM_DEBUG(llvm::dbgs() << "Flag field is not a record: "
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<< "unknown std::call_once implementation, "
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<< "ignoring the call.\n");
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return nullptr;
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}
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// We initially assume libc++ implementation of call_once,
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// where the once_flag struct has a field `__state_`.
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ValueDecl *FlagFieldDecl = M.findMemberField(FlagRecordDecl, "__state_");
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// Otherwise, try libstdc++ implementation, with a field
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// `_M_once`
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if (!FlagFieldDecl) {
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FlagFieldDecl = M.findMemberField(FlagRecordDecl, "_M_once");
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}
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if (!FlagFieldDecl) {
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LLVM_DEBUG(llvm::dbgs() << "No field _M_once or __state_ found on "
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<< "std::once_flag struct: unknown std::call_once "
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<< "implementation, ignoring the call.");
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return nullptr;
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}
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bool isLambdaCall = CallbackRecordDecl && CallbackRecordDecl->isLambda();
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if (CallbackRecordDecl && !isLambdaCall) {
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LLVM_DEBUG(llvm::dbgs()
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<< "Not supported: synthesizing body for functors when "
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<< "body farming std::call_once, ignoring the call.");
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return nullptr;
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}
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SmallVector<Expr *, 5> CallArgs;
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const FunctionProtoType *CallbackFunctionType;
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if (isLambdaCall) {
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// Lambda requires callback itself inserted as a first parameter.
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CallArgs.push_back(
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M.makeDeclRefExpr(Callback,
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/* RefersToEnclosingVariableOrCapture=*/ true));
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CallbackFunctionType = CallbackRecordDecl->getLambdaCallOperator()
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->getType()
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->getAs<FunctionProtoType>();
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} else if (!CallbackType->getPointeeType().isNull()) {
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CallbackFunctionType =
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CallbackType->getPointeeType()->getAs<FunctionProtoType>();
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} else {
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CallbackFunctionType = CallbackType->getAs<FunctionProtoType>();
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}
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if (!CallbackFunctionType)
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return nullptr;
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// First two arguments are used for the flag and for the callback.
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if (D->getNumParams() != CallbackFunctionType->getNumParams() + 2) {
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LLVM_DEBUG(llvm::dbgs() << "Types of params of the callback do not match "
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<< "params passed to std::call_once, "
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<< "ignoring the call\n");
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return nullptr;
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}
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// All arguments past first two ones are passed to the callback,
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// and we turn lvalues into rvalues if the argument is not passed by
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// reference.
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for (unsigned int ParamIdx = 2; ParamIdx < D->getNumParams(); ParamIdx++) {
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const ParmVarDecl *PDecl = D->getParamDecl(ParamIdx);
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assert(PDecl);
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if (CallbackFunctionType->getParamType(ParamIdx - 2)
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.getNonReferenceType()
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.getCanonicalType() !=
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PDecl->getType().getNonReferenceType().getCanonicalType()) {
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LLVM_DEBUG(llvm::dbgs() << "Types of params of the callback do not match "
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<< "params passed to std::call_once, "
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<< "ignoring the call\n");
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return nullptr;
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}
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Expr *ParamExpr = M.makeDeclRefExpr(PDecl);
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if (!CallbackFunctionType->getParamType(ParamIdx - 2)->isReferenceType()) {
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QualType PTy = PDecl->getType().getNonReferenceType();
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ParamExpr = M.makeLvalueToRvalue(ParamExpr, PTy);
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}
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CallArgs.push_back(ParamExpr);
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}
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CallExpr *CallbackCall;
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if (isLambdaCall) {
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CallbackCall = create_call_once_lambda_call(C, M, Callback,
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CallbackRecordDecl, CallArgs);
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} else {
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// Function pointer case.
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CallbackCall = create_call_once_funcptr_call(C, M, Callback, CallArgs);
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}
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DeclRefExpr *FlagDecl =
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M.makeDeclRefExpr(Flag,
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/* RefersToEnclosingVariableOrCapture=*/true);
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MemberExpr *Deref = M.makeMemberExpression(FlagDecl, FlagFieldDecl);
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assert(Deref->isLValue());
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QualType DerefType = Deref->getType();
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// Negation predicate.
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UnaryOperator *FlagCheck = UnaryOperator::Create(
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C,
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/* input=*/
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M.makeImplicitCast(M.makeLvalueToRvalue(Deref, DerefType), DerefType,
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CK_IntegralToBoolean),
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/* opc=*/UO_LNot,
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/* QualType=*/C.IntTy,
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/* ExprValueKind=*/VK_RValue,
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/* ExprObjectKind=*/OK_Ordinary, SourceLocation(),
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/* CanOverflow*/ false, FPOptionsOverride());
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// Create assignment.
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BinaryOperator *FlagAssignment = M.makeAssignment(
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Deref, M.makeIntegralCast(M.makeIntegerLiteral(1, C.IntTy), DerefType),
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DerefType);
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auto *Out =
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IfStmt::Create(C, SourceLocation(),
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/* IsConstexpr=*/false,
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/* Init=*/nullptr,
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/* Var=*/nullptr,
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/* Cond=*/FlagCheck,
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/* LPL=*/SourceLocation(),
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/* RPL=*/SourceLocation(),
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/* Then=*/M.makeCompound({CallbackCall, FlagAssignment}));
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return Out;
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}
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/// Create a fake body for dispatch_once.
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static Stmt *create_dispatch_once(ASTContext &C, const FunctionDecl *D) {
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// Check if we have at least two parameters.
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if (D->param_size() != 2)
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return nullptr;
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// Check if the first parameter is a pointer to integer type.
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const ParmVarDecl *Predicate = D->getParamDecl(0);
|
|
QualType PredicateQPtrTy = Predicate->getType();
|
|
const PointerType *PredicatePtrTy = PredicateQPtrTy->getAs<PointerType>();
|
|
if (!PredicatePtrTy)
|
|
return nullptr;
|
|
QualType PredicateTy = PredicatePtrTy->getPointeeType();
|
|
if (!PredicateTy->isIntegerType())
|
|
return nullptr;
|
|
|
|
// Check if the second parameter is the proper block type.
|
|
const ParmVarDecl *Block = D->getParamDecl(1);
|
|
QualType Ty = Block->getType();
|
|
if (!isDispatchBlock(Ty))
|
|
return nullptr;
|
|
|
|
// Everything checks out. Create a fakse body that checks the predicate,
|
|
// sets it, and calls the block. Basically, an AST dump of:
|
|
//
|
|
// void dispatch_once(dispatch_once_t *predicate, dispatch_block_t block) {
|
|
// if (*predicate != ~0l) {
|
|
// *predicate = ~0l;
|
|
// block();
|
|
// }
|
|
// }
|
|
|
|
ASTMaker M(C);
|
|
|
|
// (1) Create the call.
|
|
CallExpr *CE = CallExpr::Create(
|
|
/*ASTContext=*/C,
|
|
/*StmtClass=*/M.makeLvalueToRvalue(/*Expr=*/Block),
|
|
/*Args=*/None,
|
|
/*QualType=*/C.VoidTy,
|
|
/*ExprValueType=*/VK_RValue,
|
|
/*SourceLocation=*/SourceLocation(), FPOptionsOverride());
|
|
|
|
// (2) Create the assignment to the predicate.
|
|
Expr *DoneValue =
|
|
UnaryOperator::Create(C, M.makeIntegerLiteral(0, C.LongTy), UO_Not,
|
|
C.LongTy, VK_RValue, OK_Ordinary, SourceLocation(),
|
|
/*CanOverflow*/ false, FPOptionsOverride());
|
|
|
|
BinaryOperator *B =
|
|
M.makeAssignment(
|
|
M.makeDereference(
|
|
M.makeLvalueToRvalue(
|
|
M.makeDeclRefExpr(Predicate), PredicateQPtrTy),
|
|
PredicateTy),
|
|
M.makeIntegralCast(DoneValue, PredicateTy),
|
|
PredicateTy);
|
|
|
|
// (3) Create the compound statement.
|
|
Stmt *Stmts[] = { B, CE };
|
|
CompoundStmt *CS = M.makeCompound(Stmts);
|
|
|
|
// (4) Create the 'if' condition.
|
|
ImplicitCastExpr *LValToRval =
|
|
M.makeLvalueToRvalue(
|
|
M.makeDereference(
|
|
M.makeLvalueToRvalue(
|
|
M.makeDeclRefExpr(Predicate),
|
|
PredicateQPtrTy),
|
|
PredicateTy),
|
|
PredicateTy);
|
|
|
|
Expr *GuardCondition = M.makeComparison(LValToRval, DoneValue, BO_NE);
|
|
// (5) Create the 'if' statement.
|
|
auto *If = IfStmt::Create(C, SourceLocation(),
|
|
/* IsConstexpr=*/false,
|
|
/* Init=*/nullptr,
|
|
/* Var=*/nullptr,
|
|
/* Cond=*/GuardCondition,
|
|
/* LPL=*/SourceLocation(),
|
|
/* RPL=*/SourceLocation(),
|
|
/* Then=*/CS);
|
|
return If;
|
|
}
|
|
|
|
/// Create a fake body for dispatch_sync.
|
|
static Stmt *create_dispatch_sync(ASTContext &C, const FunctionDecl *D) {
|
|
// Check if we have at least two parameters.
|
|
if (D->param_size() != 2)
|
|
return nullptr;
|
|
|
|
// Check if the second parameter is a block.
|
|
const ParmVarDecl *PV = D->getParamDecl(1);
|
|
QualType Ty = PV->getType();
|
|
if (!isDispatchBlock(Ty))
|
|
return nullptr;
|
|
|
|
// Everything checks out. Create a fake body that just calls the block.
|
|
// This is basically just an AST dump of:
|
|
//
|
|
// void dispatch_sync(dispatch_queue_t queue, void (^block)(void)) {
|
|
// block();
|
|
// }
|
|
//
|
|
ASTMaker M(C);
|
|
DeclRefExpr *DR = M.makeDeclRefExpr(PV);
|
|
ImplicitCastExpr *ICE = M.makeLvalueToRvalue(DR, Ty);
|
|
CallExpr *CE = CallExpr::Create(C, ICE, None, C.VoidTy, VK_RValue,
|
|
SourceLocation(), FPOptionsOverride());
|
|
return CE;
|
|
}
|
|
|
|
static Stmt *create_OSAtomicCompareAndSwap(ASTContext &C, const FunctionDecl *D)
|
|
{
|
|
// There are exactly 3 arguments.
|
|
if (D->param_size() != 3)
|
|
return nullptr;
|
|
|
|
// Signature:
|
|
// _Bool OSAtomicCompareAndSwapPtr(void *__oldValue,
|
|
// void *__newValue,
|
|
// void * volatile *__theValue)
|
|
// Generate body:
|
|
// if (oldValue == *theValue) {
|
|
// *theValue = newValue;
|
|
// return YES;
|
|
// }
|
|
// else return NO;
|
|
|
|
QualType ResultTy = D->getReturnType();
|
|
bool isBoolean = ResultTy->isBooleanType();
|
|
if (!isBoolean && !ResultTy->isIntegralType(C))
|
|
return nullptr;
|
|
|
|
const ParmVarDecl *OldValue = D->getParamDecl(0);
|
|
QualType OldValueTy = OldValue->getType();
|
|
|
|
const ParmVarDecl *NewValue = D->getParamDecl(1);
|
|
QualType NewValueTy = NewValue->getType();
|
|
|
|
assert(OldValueTy == NewValueTy);
|
|
|
|
const ParmVarDecl *TheValue = D->getParamDecl(2);
|
|
QualType TheValueTy = TheValue->getType();
|
|
const PointerType *PT = TheValueTy->getAs<PointerType>();
|
|
if (!PT)
|
|
return nullptr;
|
|
QualType PointeeTy = PT->getPointeeType();
|
|
|
|
ASTMaker M(C);
|
|
// Construct the comparison.
|
|
Expr *Comparison =
|
|
M.makeComparison(
|
|
M.makeLvalueToRvalue(M.makeDeclRefExpr(OldValue), OldValueTy),
|
|
M.makeLvalueToRvalue(
|
|
M.makeDereference(
|
|
M.makeLvalueToRvalue(M.makeDeclRefExpr(TheValue), TheValueTy),
|
|
PointeeTy),
|
|
PointeeTy),
|
|
BO_EQ);
|
|
|
|
// Construct the body of the IfStmt.
|
|
Stmt *Stmts[2];
|
|
Stmts[0] =
|
|
M.makeAssignment(
|
|
M.makeDereference(
|
|
M.makeLvalueToRvalue(M.makeDeclRefExpr(TheValue), TheValueTy),
|
|
PointeeTy),
|
|
M.makeLvalueToRvalue(M.makeDeclRefExpr(NewValue), NewValueTy),
|
|
NewValueTy);
|
|
|
|
Expr *BoolVal = M.makeObjCBool(true);
|
|
Expr *RetVal = isBoolean ? M.makeIntegralCastToBoolean(BoolVal)
|
|
: M.makeIntegralCast(BoolVal, ResultTy);
|
|
Stmts[1] = M.makeReturn(RetVal);
|
|
CompoundStmt *Body = M.makeCompound(Stmts);
|
|
|
|
// Construct the else clause.
|
|
BoolVal = M.makeObjCBool(false);
|
|
RetVal = isBoolean ? M.makeIntegralCastToBoolean(BoolVal)
|
|
: M.makeIntegralCast(BoolVal, ResultTy);
|
|
Stmt *Else = M.makeReturn(RetVal);
|
|
|
|
/// Construct the If.
|
|
auto *If =
|
|
IfStmt::Create(C, SourceLocation(),
|
|
/* IsConstexpr=*/false,
|
|
/* Init=*/nullptr,
|
|
/* Var=*/nullptr, Comparison,
|
|
/* LPL=*/SourceLocation(),
|
|
/* RPL=*/SourceLocation(), Body, SourceLocation(), Else);
|
|
|
|
return If;
|
|
}
|
|
|
|
Stmt *BodyFarm::getBody(const FunctionDecl *D) {
|
|
Optional<Stmt *> &Val = Bodies[D];
|
|
if (Val.hasValue())
|
|
return Val.getValue();
|
|
|
|
Val = nullptr;
|
|
|
|
if (D->getIdentifier() == nullptr)
|
|
return nullptr;
|
|
|
|
StringRef Name = D->getName();
|
|
if (Name.empty())
|
|
return nullptr;
|
|
|
|
FunctionFarmer FF;
|
|
|
|
if (Name.startswith("OSAtomicCompareAndSwap") ||
|
|
Name.startswith("objc_atomicCompareAndSwap")) {
|
|
FF = create_OSAtomicCompareAndSwap;
|
|
} else if (Name == "call_once" && D->getDeclContext()->isStdNamespace()) {
|
|
FF = create_call_once;
|
|
} else {
|
|
FF = llvm::StringSwitch<FunctionFarmer>(Name)
|
|
.Case("dispatch_sync", create_dispatch_sync)
|
|
.Case("dispatch_once", create_dispatch_once)
|
|
.Default(nullptr);
|
|
}
|
|
|
|
if (FF) { Val = FF(C, D); }
|
|
else if (Injector) { Val = Injector->getBody(D); }
|
|
return Val.getValue();
|
|
}
|
|
|
|
static const ObjCIvarDecl *findBackingIvar(const ObjCPropertyDecl *Prop) {
|
|
const ObjCIvarDecl *IVar = Prop->getPropertyIvarDecl();
|
|
|
|
if (IVar)
|
|
return IVar;
|
|
|
|
// When a readonly property is shadowed in a class extensions with a
|
|
// a readwrite property, the instance variable belongs to the shadowing
|
|
// property rather than the shadowed property. If there is no instance
|
|
// variable on a readonly property, check to see whether the property is
|
|
// shadowed and if so try to get the instance variable from shadowing
|
|
// property.
|
|
if (!Prop->isReadOnly())
|
|
return nullptr;
|
|
|
|
auto *Container = cast<ObjCContainerDecl>(Prop->getDeclContext());
|
|
const ObjCInterfaceDecl *PrimaryInterface = nullptr;
|
|
if (auto *InterfaceDecl = dyn_cast<ObjCInterfaceDecl>(Container)) {
|
|
PrimaryInterface = InterfaceDecl;
|
|
} else if (auto *CategoryDecl = dyn_cast<ObjCCategoryDecl>(Container)) {
|
|
PrimaryInterface = CategoryDecl->getClassInterface();
|
|
} else if (auto *ImplDecl = dyn_cast<ObjCImplDecl>(Container)) {
|
|
PrimaryInterface = ImplDecl->getClassInterface();
|
|
} else {
|
|
return nullptr;
|
|
}
|
|
|
|
// FindPropertyVisibleInPrimaryClass() looks first in class extensions, so it
|
|
// is guaranteed to find the shadowing property, if it exists, rather than
|
|
// the shadowed property.
|
|
auto *ShadowingProp = PrimaryInterface->FindPropertyVisibleInPrimaryClass(
|
|
Prop->getIdentifier(), Prop->getQueryKind());
|
|
if (ShadowingProp && ShadowingProp != Prop) {
|
|
IVar = ShadowingProp->getPropertyIvarDecl();
|
|
}
|
|
|
|
return IVar;
|
|
}
|
|
|
|
static Stmt *createObjCPropertyGetter(ASTContext &Ctx,
|
|
const ObjCMethodDecl *MD) {
|
|
// First, find the backing ivar.
|
|
const ObjCIvarDecl *IVar = nullptr;
|
|
|
|
// Property accessor stubs sometimes do not correspond to any property decl
|
|
// in the current interface (but in a superclass). They still have a
|
|
// corresponding property impl decl in this case.
|
|
if (MD->isSynthesizedAccessorStub()) {
|
|
const ObjCInterfaceDecl *IntD = MD->getClassInterface();
|
|
const ObjCImplementationDecl *ImpD = IntD->getImplementation();
|
|
for (const auto *PI: ImpD->property_impls()) {
|
|
if (const ObjCPropertyDecl *P = PI->getPropertyDecl()) {
|
|
if (P->getGetterName() == MD->getSelector())
|
|
IVar = P->getPropertyIvarDecl();
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!IVar) {
|
|
const ObjCPropertyDecl *Prop = MD->findPropertyDecl();
|
|
IVar = findBackingIvar(Prop);
|
|
if (!IVar)
|
|
return nullptr;
|
|
|
|
// Ignore weak variables, which have special behavior.
|
|
if (Prop->getPropertyAttributes() & ObjCPropertyAttribute::kind_weak)
|
|
return nullptr;
|
|
|
|
// Look to see if Sema has synthesized a body for us. This happens in
|
|
// Objective-C++ because the return value may be a C++ class type with a
|
|
// non-trivial copy constructor. We can only do this if we can find the
|
|
// @synthesize for this property, though (or if we know it's been auto-
|
|
// synthesized).
|
|
const ObjCImplementationDecl *ImplDecl =
|
|
IVar->getContainingInterface()->getImplementation();
|
|
if (ImplDecl) {
|
|
for (const auto *I : ImplDecl->property_impls()) {
|
|
if (I->getPropertyDecl() != Prop)
|
|
continue;
|
|
|
|
if (I->getGetterCXXConstructor()) {
|
|
ASTMaker M(Ctx);
|
|
return M.makeReturn(I->getGetterCXXConstructor());
|
|
}
|
|
}
|
|
}
|
|
|
|
// Sanity check that the property is the same type as the ivar, or a
|
|
// reference to it, and that it is either an object pointer or trivially
|
|
// copyable.
|
|
if (!Ctx.hasSameUnqualifiedType(IVar->getType(),
|
|
Prop->getType().getNonReferenceType()))
|
|
return nullptr;
|
|
if (!IVar->getType()->isObjCLifetimeType() &&
|
|
!IVar->getType().isTriviallyCopyableType(Ctx))
|
|
return nullptr;
|
|
}
|
|
|
|
// Generate our body:
|
|
// return self->_ivar;
|
|
ASTMaker M(Ctx);
|
|
|
|
const VarDecl *selfVar = MD->getSelfDecl();
|
|
if (!selfVar)
|
|
return nullptr;
|
|
|
|
Expr *loadedIVar =
|
|
M.makeObjCIvarRef(
|
|
M.makeLvalueToRvalue(
|
|
M.makeDeclRefExpr(selfVar),
|
|
selfVar->getType()),
|
|
IVar);
|
|
|
|
if (!MD->getReturnType()->isReferenceType())
|
|
loadedIVar = M.makeLvalueToRvalue(loadedIVar, IVar->getType());
|
|
|
|
return M.makeReturn(loadedIVar);
|
|
}
|
|
|
|
Stmt *BodyFarm::getBody(const ObjCMethodDecl *D) {
|
|
// We currently only know how to synthesize property accessors.
|
|
if (!D->isPropertyAccessor())
|
|
return nullptr;
|
|
|
|
D = D->getCanonicalDecl();
|
|
|
|
// We should not try to synthesize explicitly redefined accessors.
|
|
// We do not know for sure how they behave.
|
|
if (!D->isImplicit())
|
|
return nullptr;
|
|
|
|
Optional<Stmt *> &Val = Bodies[D];
|
|
if (Val.hasValue())
|
|
return Val.getValue();
|
|
Val = nullptr;
|
|
|
|
// For now, we only synthesize getters.
|
|
// Synthesizing setters would cause false negatives in the
|
|
// RetainCountChecker because the method body would bind the parameter
|
|
// to an instance variable, causing it to escape. This would prevent
|
|
// warning in the following common scenario:
|
|
//
|
|
// id foo = [[NSObject alloc] init];
|
|
// self.foo = foo; // We should warn that foo leaks here.
|
|
//
|
|
if (D->param_size() != 0)
|
|
return nullptr;
|
|
|
|
// If the property was defined in an extension, search the extensions for
|
|
// overrides.
|
|
const ObjCInterfaceDecl *OID = D->getClassInterface();
|
|
if (dyn_cast<ObjCInterfaceDecl>(D->getParent()) != OID)
|
|
for (auto *Ext : OID->known_extensions()) {
|
|
auto *OMD = Ext->getInstanceMethod(D->getSelector());
|
|
if (OMD && !OMD->isImplicit())
|
|
return nullptr;
|
|
}
|
|
|
|
Val = createObjCPropertyGetter(C, D);
|
|
|
|
return Val.getValue();
|
|
}
|