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

   1 //===--- DynamicStaticInitializersCheck.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 "DynamicStaticInitializersCheck.h"
  10 #include "../utils/FileExtensionsUtils.h"
  11 #include "clang/AST/ASTContext.h"
  12 #include "clang/ASTMatchers/ASTMatchFinder.h"
  13
  14 using namespace clang::ast_matchers;
  15
  16 namespace clang::tidy::bugprone {
  17
  18 AST_MATCHER(clang::VarDecl, hasConstantDeclaration) {
  19   const Expr *Init = Node.getInit();
  20   if (Init && !Init->isValueDependent()) {
  21     if (Node.isConstexpr())
  22       return true;
  23     return Node.evaluateValue();
  24   }
  25   return false;
  26 }
  27
  28 DynamicStaticInitializersCheck::DynamicStaticInitializersCheck(
  29     StringRef Name, ClangTidyContext *Context)
  30     : ClangTidyCheck(Name, Context),
  31       HeaderFileExtensions(Context->getHeaderFileExtensions()) {}
  32
  33 void DynamicStaticInitializersCheck::registerMatchers(MatchFinder *Finder) {
  34   Finder->addMatcher(
  35       varDecl(hasGlobalStorage(), unless(hasConstantDeclaration())).bind("var"),
  36       this);
  37 }
  38
  39 void DynamicStaticInitializersCheck::check(const MatchFinder::MatchResult &Result) {
  40   const auto *Var = Result.Nodes.getNodeAs<VarDecl>("var");
  41   SourceLocation Loc = Var->getLocation();
  42   if (!Loc.isValid() || !utils::isPresumedLocInHeaderFile(Loc, *Result.SourceManager,
  43                                                           HeaderFileExtensions))
  44     return;
  45   // If the initializer is a constant expression, then the compiler
  46   // doesn't have to dynamically initialize it.
  47   diag(Loc, "static variable %0 may be dynamically initialized in this header file")
  48     << Var;
  49 }
  50
  51 } // namespace clang::tidy::bugprone