clang-tools-extra/clang-tidy/modernize/AvoidCArraysCheck.cpp

   1 //===--- AvoidCArraysCheck.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 "AvoidCArraysCheck.h"
  10 #include "clang/AST/ASTContext.h"
  11 #include "clang/ASTMatchers/ASTMatchFinder.h"
  12
  13 using namespace clang::ast_matchers;
  14
  15 namespace {
  16
  17 AST_MATCHER(clang::TypeLoc, hasValidBeginLoc) {
  18   return Node.getBeginLoc().isValid();
  19 }
  20
  21 AST_MATCHER_P(clang::TypeLoc, hasType,
  22               clang::ast_matchers::internal::Matcher<clang::Type>,
  23               InnerMatcher) {
  24   const clang::Type *TypeNode = Node.getTypePtr();
  25   return TypeNode != nullptr &&
  26          InnerMatcher.matches(*TypeNode, Finder, Builder);
  27 }
  28
  29 AST_MATCHER(clang::RecordDecl, isExternCContext) {
  30   return Node.isExternCContext();
  31 }
  32
  33 AST_MATCHER(clang::ParmVarDecl, isArgvOfMain) {
  34   const clang::DeclContext *DC = Node.getDeclContext();
  35   const auto *FD = llvm::dyn_cast<clang::FunctionDecl>(DC);
  36   return FD ? FD->isMain() : false;
  37 }
  38
  39 } // namespace
  40
  41 namespace clang {
  42 namespace tidy {
  43 namespace modernize {
  44
  45 void AvoidCArraysCheck::registerMatchers(MatchFinder *Finder) {
  46   Finder->addMatcher(
  47       typeLoc(hasValidBeginLoc(), hasType(arrayType()),
  48               unless(anyOf(hasParent(parmVarDecl(isArgvOfMain())),
  49                            hasParent(varDecl(isExternC())),
  50                            hasParent(fieldDecl(
  51                                hasParent(recordDecl(isExternCContext())))),
  52                            hasAncestor(functionDecl(isExternC())))))
  53           .bind("typeloc"),
  54       this);
  55 }
  56
  57 void AvoidCArraysCheck::check(const MatchFinder::MatchResult &Result) {
  58   const auto *ArrayType = Result.Nodes.getNodeAs<TypeLoc>("typeloc");
  59
  60   diag(ArrayType->getBeginLoc(),
  61        "do not declare %select{C-style|C VLA}0 arrays, use "
  62        "%select{std::array<>|std::vector<>}0 instead")
  63       << ArrayType->getTypePtr()->isVariableArrayType();
  64 }
  65
  66 } // namespace modernize
  67 } // namespace tidy
  68 } // namespace clang