| 1 | //===--- AvoidNonConstGlobalVariablesCheck.cpp - clang-tidy ---------------===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | #include "AvoidNonConstGlobalVariablesCheck.h" |
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| 10 | #include "clang/ASTMatchers/ASTMatchFinder.h" |
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| 11 | #include "clang/ASTMatchers/ASTMatchers.h" |
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| 12 | |
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| 13 | using namespace clang::ast_matchers; |
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| 14 | |
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| 15 | namespace clang::tidy::cppcoreguidelines { |
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| 16 | |
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| 17 | AvoidNonConstGlobalVariablesCheck::AvoidNonConstGlobalVariablesCheck( |
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| 18 | StringRef Name, ClangTidyContext *Context) |
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| 19 | : ClangTidyCheck(Name, Context), |
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| 20 | AllowInternalLinkage(Options.get(LocalName: "AllowInternalLinkage" , Default: false)) {} |
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| 21 | |
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| 22 | void AvoidNonConstGlobalVariablesCheck::registerMatchers(MatchFinder *Finder) { |
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| 23 | auto NamespaceMatcher = AllowInternalLinkage |
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| 24 | ? namespaceDecl(unless(isAnonymous())) |
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| 25 | : namespaceDecl(); |
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| 26 | auto GlobalContext = |
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| 27 | varDecl(hasGlobalStorage(), |
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| 28 | hasDeclContext(InnerMatcher: anyOf(NamespaceMatcher, translationUnitDecl()))); |
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| 29 | |
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| 30 | auto GlobalVariable = varDecl( |
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| 31 | GlobalContext, |
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| 32 | AllowInternalLinkage ? varDecl(unless(isStaticStorageClass())) |
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| 33 | : varDecl(), |
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| 34 | unless(anyOf( |
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| 35 | isConstexpr(), hasType(InnerMatcher: isConstQualified()), |
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| 36 | hasType(InnerMatcher: referenceType())))); // References can't be changed, only the |
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| 37 | // data they reference can be changed. |
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| 38 | |
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| 39 | auto GlobalReferenceToNonConst = |
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| 40 | varDecl(GlobalContext, hasType(InnerMatcher: referenceType()), |
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| 41 | unless(hasType(InnerMatcher: references(InnerMatcher: qualType(isConstQualified()))))); |
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| 42 | |
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| 43 | auto GlobalPointerToNonConst = varDecl( |
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| 44 | GlobalContext, hasType(InnerMatcher: pointerType(pointee(unless(isConstQualified()))))); |
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| 45 | |
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| 46 | Finder->addMatcher(NodeMatch: GlobalVariable.bind(ID: "non-const_variable" ), Action: this); |
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| 47 | Finder->addMatcher(NodeMatch: GlobalReferenceToNonConst.bind(ID: "indirection_to_non-const" ), |
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| 48 | Action: this); |
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| 49 | Finder->addMatcher(NodeMatch: GlobalPointerToNonConst.bind(ID: "indirection_to_non-const" ), |
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| 50 | Action: this); |
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| 51 | } |
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| 52 | |
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| 53 | void AvoidNonConstGlobalVariablesCheck::check( |
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| 54 | const MatchFinder::MatchResult &Result) { |
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| 55 | if (const auto *Variable = |
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| 56 | Result.Nodes.getNodeAs<VarDecl>(ID: "non-const_variable" )) { |
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| 57 | diag(Variable->getLocation(), "variable %0 is non-const and globally " |
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| 58 | "accessible, consider making it const" ) |
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| 59 | << Variable; // FIXME: Add fix-it hint to Variable |
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| 60 | // Don't return early, a non-const variable may also be a pointer or |
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| 61 | // reference to non-const data. |
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| 62 | } |
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| 63 | |
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| 64 | if (const auto *VD = |
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| 65 | Result.Nodes.getNodeAs<VarDecl>(ID: "indirection_to_non-const" )) { |
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| 66 | diag(VD->getLocation(), |
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| 67 | "variable %0 provides global access to a non-const object; consider " |
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| 68 | "making the %select{referenced|pointed-to}1 data 'const'" ) |
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| 69 | << VD |
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| 70 | << VD->getType()->isPointerType(); // FIXME: Add fix-it hint to Variable |
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| 71 | } |
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| 72 | } |
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| 73 | |
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| 74 | void AvoidNonConstGlobalVariablesCheck::storeOptions( |
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| 75 | ClangTidyOptions::OptionMap &Opts) { |
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| 76 | Options.store(Options&: Opts, LocalName: "AllowInternalLinkage" , Value: AllowInternalLinkage); |
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| 77 | } |
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| 78 | |
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| 79 | } // namespace clang::tidy::cppcoreguidelines |
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| 80 | |
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