compilerplugins/clang/functionaddress.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9
  10 #pragma once
  11
  12 #include <clang/AST/RecursiveASTVisitor.h>
  13 #include <unordered_set>
  14 #include "plugin.hxx"
  15
  16 /**
  17  * Common code for checking if the address of a function was taken.
  18  */
  19 namespace loplugin {
  20
  21 template<typename Base>
  22 class FunctionAddress : public Base
  23 {
  24 public:
  25     explicit FunctionAddress( const InstantiationData& data ) : Base(data) {}
  26
  27     bool TraverseCallExpr(CallExpr * expr) {
  28         auto const saved = callee_;
  29         callee_ = expr->getCallee();
  30         auto const ret = Base::TraverseCallExpr(expr);
  31         callee_ = saved;
  32         return ret;
  33     }
  34
  35     bool TraverseCXXOperatorCallExpr(CXXOperatorCallExpr * expr) {
  36         auto const saved = callee_;
  37         callee_ = expr->getCallee();
  38         auto const ret = Base::TraverseCXXOperatorCallExpr(expr);
  39         callee_ = saved;
  40         return ret;
  41     }
  42
  43     bool TraverseCXXMemberCallExpr(CXXMemberCallExpr * expr) {
  44         auto const saved = callee_;
  45         callee_ = expr->getCallee();
  46         auto const ret = Base::TraverseCXXMemberCallExpr(expr);
  47         callee_ = saved;
  48         return ret;
  49     }
  50
  51     bool TraverseCUDAKernelCallExpr(CUDAKernelCallExpr * expr) {
  52         auto const saved = callee_;
  53         callee_ = expr->getCallee();
  54         auto const ret = Base::TraverseCUDAKernelCallExpr(expr);
  55         callee_ = saved;
  56         return ret;
  57     }
  58
  59     bool TraverseUserDefinedLiteral(UserDefinedLiteral * expr) {
  60         auto const saved = callee_;
  61         callee_ = expr->getCallee();
  62         auto const ret = Base::TraverseUserDefinedLiteral(expr);
  63         callee_ = saved;
  64         return ret;
  65     }
  66
  67     bool VisitImplicitCastExpr(ImplicitCastExpr const * expr) {
  68         if (expr == callee_) {
  69             return true;
  70         }
  71         if (this->ignoreLocation(expr)) {
  72             return true;
  73         }
  74         if (expr->getCastKind() != CK_FunctionToPointerDecay) {
  75             return true;
  76         }
  77         auto const dre = dyn_cast<DeclRefExpr>(
  78             expr->getSubExpr()->IgnoreParens());
  79         if (dre == nullptr) {
  80             return true;
  81         }
  82         auto const fd = dyn_cast<FunctionDecl>(dre->getDecl());
  83         if (fd == nullptr) {
  84             return true;
  85         }
  86         ignoredFunctions_.insert(fd->getCanonicalDecl());
  87         return true;
  88     }
  89
  90     bool VisitUnaryOperator(UnaryOperator * expr) {
  91         if (expr->getOpcode() != UO_AddrOf) {
  92             return Base::VisitUnaryOperator(expr);
  93         }
  94         if (this->ignoreLocation(expr)) {
  95             return true;
  96         }
  97         auto const dre = dyn_cast<DeclRefExpr>(
  98             expr->getSubExpr()->IgnoreParenImpCasts());
  99         if (dre == nullptr) {
 100             return true;
 101         }
 102         auto const fd = dyn_cast<FunctionDecl>(dre->getDecl());
 103         if (fd == nullptr) {
 104             return true;
 105         }
 106         ignoredFunctions_.insert(fd->getCanonicalDecl());
 107         return true;
 108     }
 109
 110 protected:
 111     std::unordered_set<FunctionDecl const *> const & getFunctionsWithAddressTaken() { return ignoredFunctions_; }
 112
 113 private:
 114     std::unordered_set<FunctionDecl const *> ignoredFunctions_;
 115     Expr const * callee_ = nullptr;
 116 };
 117
 118 }
 119
 120 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */