| 1 | //=======- ASTUtils.cpp ------------------------------------------*- C++ -*-==// |
|---|---|
| 2 | // |
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 4 | // See https://llvm.org/LICENSE.txt for license information. |
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | |
| 9 | #include "ASTUtils.h" |
| 10 | #include "PtrTypesSemantics.h" |
| 11 | #include "clang/AST/CXXInheritance.h" |
| 12 | #include "clang/AST/Decl.h" |
| 13 | #include "clang/AST/DeclCXX.h" |
| 14 | #include "clang/AST/ExprCXX.h" |
| 15 | #include <optional> |
| 16 | |
| 17 | namespace clang { |
| 18 | |
| 19 | std::pair<const Expr *, bool> |
| 20 | tryToFindPtrOrigin(const Expr *E, bool StopAtFirstRefCountedObj) { |
| 21 | while (E) { |
| 22 | if (auto *tempExpr = dyn_cast<MaterializeTemporaryExpr>(Val: E)) { |
| 23 | E = tempExpr->getSubExpr(); |
| 24 | continue; |
| 25 | } |
| 26 | if (auto *tempExpr = dyn_cast<CXXBindTemporaryExpr>(Val: E)) { |
| 27 | E = tempExpr->getSubExpr(); |
| 28 | continue; |
| 29 | } |
| 30 | if (auto *cast = dyn_cast<CastExpr>(Val: E)) { |
| 31 | if (StopAtFirstRefCountedObj) { |
| 32 | if (auto *ConversionFunc = |
| 33 | dyn_cast_or_null<FunctionDecl>(Val: cast->getConversionFunction())) { |
| 34 | if (isCtorOfRefCounted(F: ConversionFunc)) |
| 35 | return {E, true}; |
| 36 | } |
| 37 | } |
| 38 | // FIXME: This can give false "origin" that would lead to false negatives |
| 39 | // in checkers. See https://reviews.llvm.org/D37023 for reference. |
| 40 | E = cast->getSubExpr(); |
| 41 | continue; |
| 42 | } |
| 43 | if (auto *call = dyn_cast<CallExpr>(Val: E)) { |
| 44 | if (auto *memberCall = dyn_cast<CXXMemberCallExpr>(Val: call)) { |
| 45 | if (auto *decl = memberCall->getMethodDecl()) { |
| 46 | std::optional<bool> IsGetterOfRefCt = isGetterOfRefCounted(Method: decl); |
| 47 | if (IsGetterOfRefCt && *IsGetterOfRefCt) { |
| 48 | E = memberCall->getImplicitObjectArgument(); |
| 49 | if (StopAtFirstRefCountedObj) { |
| 50 | return {E, true}; |
| 51 | } |
| 52 | continue; |
| 53 | } |
| 54 | } |
| 55 | } |
| 56 | |
| 57 | if (auto *operatorCall = dyn_cast<CXXOperatorCallExpr>(Val: E)) { |
| 58 | if (operatorCall->getNumArgs() == 1) { |
| 59 | E = operatorCall->getArg(0); |
| 60 | continue; |
| 61 | } |
| 62 | } |
| 63 | |
| 64 | if (auto *callee = call->getDirectCallee()) { |
| 65 | if (isCtorOfRefCounted(F: callee)) { |
| 66 | if (StopAtFirstRefCountedObj) |
| 67 | return {E, true}; |
| 68 | |
| 69 | E = call->getArg(Arg: 0); |
| 70 | continue; |
| 71 | } |
| 72 | |
| 73 | if (isReturnValueRefCounted(F: callee)) |
| 74 | return {E, true}; |
| 75 | |
| 76 | if (isSingleton(F: callee)) |
| 77 | return {E, true}; |
| 78 | |
| 79 | if (isPtrConversion(F: callee)) { |
| 80 | E = call->getArg(Arg: 0); |
| 81 | continue; |
| 82 | } |
| 83 | } |
| 84 | } |
| 85 | if (auto *unaryOp = dyn_cast<UnaryOperator>(Val: E)) { |
| 86 | // FIXME: Currently accepts ANY unary operator. Is it OK? |
| 87 | E = unaryOp->getSubExpr(); |
| 88 | continue; |
| 89 | } |
| 90 | |
| 91 | break; |
| 92 | } |
| 93 | // Some other expression. |
| 94 | return {E, false}; |
| 95 | } |
| 96 | |
| 97 | bool isASafeCallArg(const Expr *E) { |
| 98 | assert(E); |
| 99 | if (auto *Ref = dyn_cast<DeclRefExpr>(Val: E)) { |
| 100 | if (auto *D = dyn_cast_or_null<VarDecl>(Val: Ref->getFoundDecl())) { |
| 101 | if (isa<ParmVarDecl>(Val: D) || D->isLocalVarDecl()) |
| 102 | return true; |
| 103 | } |
| 104 | } |
| 105 | |
| 106 | // TODO: checker for method calls on non-refcounted objects |
| 107 | return isa<CXXThisExpr>(Val: E); |
| 108 | } |
| 109 | |
| 110 | } // namespace clang |
| 111 |