ASTUtils.cpp
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//=======- ASTUtils.cpp ------------------------------------------*- C++ -*-==//
//
// 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 "ASTUtils.h"
#include "PtrTypesSemantics.h"
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/ExprCXX.h"
using llvm::Optional;
namespace clang {
std::pair<const Expr *, bool>
tryToFindPtrOrigin(const Expr *E, bool StopAtFirstRefCountedObj) {
while (E) {
if (auto *cast = dyn_cast<CastExpr>(E)) {
if (StopAtFirstRefCountedObj) {
if (auto *ConversionFunc =
dyn_cast_or_null<FunctionDecl>(cast->getConversionFunction())) {
if (isCtorOfRefCounted(ConversionFunc))
return {E, true};
}
}
// FIXME: This can give false "origin" that would lead to false negatives
// in checkers. See https://reviews.llvm.org/D37023 for reference.
E = cast->getSubExpr();
continue;
}
if (auto *call = dyn_cast<CallExpr>(E)) {
if (auto *memberCall = dyn_cast<CXXMemberCallExpr>(call)) {
Optional<bool> IsGetterOfRefCt =
isGetterOfRefCounted(memberCall->getMethodDecl());
if (IsGetterOfRefCt && *IsGetterOfRefCt) {
E = memberCall->getImplicitObjectArgument();
if (StopAtFirstRefCountedObj) {
return {E, true};
}
continue;
}
}
if (auto *operatorCall = dyn_cast<CXXOperatorCallExpr>(E)) {
if (operatorCall->getNumArgs() == 1) {
E = operatorCall->getArg(0);
continue;
}
}
if (auto *callee = call->getDirectCallee()) {
if (isCtorOfRefCounted(callee)) {
if (StopAtFirstRefCountedObj)
return {E, true};
E = call->getArg(0);
continue;
}
if (isPtrConversion(callee)) {
E = call->getArg(0);
continue;
}
}
}
if (auto *unaryOp = dyn_cast<UnaryOperator>(E)) {
// FIXME: Currently accepts ANY unary operator. Is it OK?
E = unaryOp->getSubExpr();
continue;
}
break;
}
// Some other expression.
return {E, false};
}
bool isASafeCallArg(const Expr *E) {
assert(E);
if (auto *Ref = dyn_cast<DeclRefExpr>(E)) {
if (auto *D = dyn_cast_or_null<VarDecl>(Ref->getFoundDecl())) {
if (isa<ParmVarDecl>(D) || D->isLocalVarDecl())
return true;
}
}
// TODO: checker for method calls on non-refcounted objects
return isa<CXXThisExpr>(E);
}
} // namespace clang