83 lines · cpp
1//===----------------------------------------------------------------------===//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 "AvoidNonConstGlobalVariablesCheck.h"10#include "clang/ASTMatchers/ASTMatchFinder.h"11#include "clang/ASTMatchers/ASTMatchers.h"12 13using namespace clang::ast_matchers;14 15namespace clang::tidy::cppcoreguidelines {16 17AvoidNonConstGlobalVariablesCheck::AvoidNonConstGlobalVariablesCheck(18 StringRef Name, ClangTidyContext *Context)19 : ClangTidyCheck(Name, Context),20 AllowInternalLinkage(Options.get("AllowInternalLinkage", false)),21 AllowThreadLocal(Options.get("AllowThreadLocal", false)) {}22 23void AvoidNonConstGlobalVariablesCheck::registerMatchers(MatchFinder *Finder) {24 auto NamespaceMatcher = AllowInternalLinkage25 ? namespaceDecl(unless(isAnonymous()))26 : namespaceDecl();27 auto GlobalContext =28 varDecl(hasGlobalStorage(),29 hasDeclContext(anyOf(NamespaceMatcher, translationUnitDecl())));30 31 auto GlobalVariable = varDecl(32 GlobalContext,33 AllowInternalLinkage ? varDecl(unless(isStaticStorageClass()))34 : varDecl(),35 AllowThreadLocal ? varDecl(unless(hasThreadStorageDuration()))36 : varDecl(),37 unless(anyOf(38 isConstexpr(), hasType(isConstQualified()),39 hasType(referenceType())))); // References can't be changed, only the40 // data they reference can be changed.41 42 auto GlobalReferenceToNonConst =43 varDecl(GlobalContext, hasType(referenceType()),44 unless(hasType(references(qualType(isConstQualified())))));45 46 auto GlobalPointerToNonConst = varDecl(47 GlobalContext, hasType(pointerType(pointee(unless(isConstQualified())))));48 49 Finder->addMatcher(GlobalVariable.bind("non-const_variable"), this);50 Finder->addMatcher(GlobalReferenceToNonConst.bind("indirection_to_non-const"),51 this);52 Finder->addMatcher(GlobalPointerToNonConst.bind("indirection_to_non-const"),53 this);54}55 56void AvoidNonConstGlobalVariablesCheck::check(57 const MatchFinder::MatchResult &Result) {58 if (const auto *Variable =59 Result.Nodes.getNodeAs<VarDecl>("non-const_variable")) {60 diag(Variable->getLocation(), "variable %0 is non-const and globally "61 "accessible, consider making it const")62 << Variable; // FIXME: Add fix-it hint to Variable63 // Don't return early, a non-const variable may also be a pointer or64 // reference to non-const data.65 }66 67 if (const auto *VD =68 Result.Nodes.getNodeAs<VarDecl>("indirection_to_non-const")) {69 diag(VD->getLocation(),70 "variable %0 provides global access to a non-const object; consider "71 "making the %select{referenced|pointed-to}1 data 'const'")72 << VD73 << VD->getType()->isPointerType(); // FIXME: Add fix-it hint to Variable74 }75}76 77void AvoidNonConstGlobalVariablesCheck::storeOptions(78 ClangTidyOptions::OptionMap &Opts) {79 Options.store(Opts, "AllowInternalLinkage", AllowInternalLinkage);80}81 82} // namespace clang::tidy::cppcoreguidelines83