107 lines · cpp
1//===- LowLevelHelpers.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-exception6//7//===----------------------------------------------------------------------===//8 9#include "clang/ASTMatchers/LowLevelHelpers.h"10#include "clang/AST/Decl.h"11#include "clang/AST/DeclCXX.h"12#include "clang/AST/Expr.h"13#include "clang/AST/ExprCXX.h"14#include <type_traits>15 16namespace clang {17namespace ast_matchers {18 19static const FunctionDecl *getCallee(const CXXConstructExpr &D) {20 return D.getConstructor();21}22static const FunctionDecl *getCallee(const CallExpr &D) {23 return D.getDirectCallee();24}25 26template <class ExprNode>27static void matchEachArgumentWithParamTypeImpl(28 const ExprNode &Node,29 llvm::function_ref<void(QualType /*Param*/, const Expr * /*Arg*/)>30 OnParamAndArg) {31 static_assert(std::is_same_v<CallExpr, ExprNode> ||32 std::is_same_v<CXXConstructExpr, ExprNode>);33 // The first argument of an overloaded member operator is the implicit object34 // argument of the method which should not be matched against a parameter, so35 // we skip over it here.36 unsigned ArgIndex = 0;37 if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(&Node)) {38 const auto *MD = dyn_cast_or_null<CXXMethodDecl>(CE->getDirectCallee());39 if (MD && !MD->isExplicitObjectMemberFunction()) {40 // This is an overloaded operator call.41 // We need to skip the first argument, which is the implicit object42 // argument of the method which should not be matched against a43 // parameter.44 ++ArgIndex;45 }46 }47 48 const FunctionProtoType *FProto = nullptr;49 50 if (const auto *Call = dyn_cast<CallExpr>(&Node)) {51 if (const auto *Value =52 dyn_cast_or_null<ValueDecl>(Call->getCalleeDecl())) {53 QualType QT = Value->getType().getCanonicalType();54 55 // This does not necessarily lead to a `FunctionProtoType`,56 // e.g. K&R functions do not have a function prototype.57 if (QT->isFunctionPointerType())58 FProto = QT->getPointeeType()->getAs<FunctionProtoType>();59 60 if (QT->isMemberFunctionPointerType()) {61 const auto *MP = QT->getAs<MemberPointerType>();62 assert(MP && "Must be member-pointer if its a memberfunctionpointer");63 FProto = MP->getPointeeType()->getAs<FunctionProtoType>();64 assert(FProto &&65 "The call must have happened through a member function "66 "pointer");67 }68 }69 }70 71 unsigned ParamIndex = 0;72 unsigned NumArgs = Node.getNumArgs();73 if (FProto && FProto->isVariadic())74 NumArgs = std::min(NumArgs, FProto->getNumParams());75 76 for (; ArgIndex < NumArgs; ++ArgIndex, ++ParamIndex) {77 QualType ParamType;78 if (FProto && FProto->getNumParams() > ParamIndex)79 ParamType = FProto->getParamType(ParamIndex);80 else if (const FunctionDecl *FD = getCallee(Node);81 FD && FD->getNumParams() > ParamIndex)82 ParamType = FD->getParamDecl(ParamIndex)->getType();83 else84 continue;85 86 OnParamAndArg(ParamType, Node.getArg(ArgIndex)->IgnoreParenCasts());87 }88}89 90void matchEachArgumentWithParamType(91 const CallExpr &Node,92 llvm::function_ref<void(QualType /*Param*/, const Expr * /*Arg*/)>93 OnParamAndArg) {94 matchEachArgumentWithParamTypeImpl(Node, OnParamAndArg);95}96 97void matchEachArgumentWithParamType(98 const CXXConstructExpr &Node,99 llvm::function_ref<void(QualType /*Param*/, const Expr * /*Arg*/)>100 OnParamAndArg) {101 matchEachArgumentWithParamTypeImpl(Node, OnParamAndArg);102}103 104} // namespace ast_matchers105 106} // namespace clang107