clang-tools-extra/clang-tidy/bugprone/SizeofContainerCheck.cpp

   1 //===--- SizeofContainerCheck.cpp - clang-tidy-----------------------------===//
   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 "SizeofContainerCheck.h"
  10 #include "clang/AST/ASTContext.h"
  11 #include "clang/ASTMatchers/ASTMatchFinder.h"
  12
  13 using namespace clang::ast_matchers;
  14
  15 namespace clang::tidy::bugprone {
  16
  17 void SizeofContainerCheck::registerMatchers(MatchFinder *Finder) {
  18   Finder->addMatcher(
  19       expr(unless(isInTemplateInstantiation()),
  20            expr(sizeOfExpr(has(ignoringParenImpCasts(
  21                     expr(hasType(hasCanonicalType(hasDeclaration(cxxRecordDecl(
  22                         matchesName("^(::std::|::string)"),
  23                         unless(matchesName("^::std::(bitset|array)$")),
  24                         hasMethod(cxxMethodDecl(hasName("size"), isPublic(),
  25                                                 isConst())))))))))))
  26                .bind("sizeof"),
  27            // Ignore ARRAYSIZE(<array of containers>) pattern.
  28            unless(hasAncestor(binaryOperator(
  29                hasAnyOperatorName("/", "%"),
  30                hasLHS(ignoringParenCasts(sizeOfExpr(expr()))),
  31                hasRHS(ignoringParenCasts(equalsBoundNode("sizeof"))))))),
  32       this);
  33 }
  34
  35 void SizeofContainerCheck::check(const MatchFinder::MatchResult &Result) {
  36   const auto *SizeOf =
  37       Result.Nodes.getNodeAs<UnaryExprOrTypeTraitExpr>("sizeof");
  38
  39   auto Diag =
  40       diag(SizeOf->getBeginLoc(), "sizeof() doesn't return the size of the "
  41                                   "container; did you mean .size()?");
  42 }
  43
  44 } // namespace clang::tidy::bugprone