llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang-tidy Author: Pascal Jungblut (pascalj) <details> <summary>Changes</summary> Add an option to ignore warnings for cppcoreguidelines avoid-non-const-global-variables. Understandably, the core guidelines discourage non const global variables, even at the TU level (see https://github.com/isocpp/CppCoreGuidelines/issues/2195). However, having a small TU with an interface that uses a non const variable from an anonymous namespace can be a valid choice. This adds an option that disables the warning just for anonymous namespaces, i.e. at the file level. The default is still to show a warning, just as before. --- Patch is 36.15 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/93827.diff 3 Files Affected: - (modified) clang-tools-extra/clang-tidy/cppcoreguidelines/AvoidNonConstGlobalVariablesCheck.cpp (+4-2) - (modified) clang-tools-extra/docs/clang-tidy/checks/cppcoreguidelines/avoid-non-const-global-variables.rst (+22) - (modified) clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/avoid-non-const-global-variables.cpp (+92-45) ``````````diff diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/AvoidNonConstGlobalVariablesCheck.cpp b/clang-tools-extra/clang-tidy/cppcoreguidelines/AvoidNonConstGlobalVariablesCheck.cpp index ee17b0e014288..b536016a3cccd 100644 --- a/clang-tools-extra/clang-tidy/cppcoreguidelines/AvoidNonConstGlobalVariablesCheck.cpp +++ b/clang-tools-extra/clang-tidy/cppcoreguidelines/AvoidNonConstGlobalVariablesCheck.cpp @@ -7,7 +7,6 @@ //===----------------------------------------------------------------------===// #include "AvoidNonConstGlobalVariablesCheck.h" -#include "clang/AST/ASTContext.h" #include "clang/ASTMatchers/ASTMatchFinder.h" #include "clang/ASTMatchers/ASTMatchers.h" @@ -16,9 +15,12 @@ using namespace clang::ast_matchers; namespace clang::tidy::cppcoreguidelines { void AvoidNonConstGlobalVariablesCheck::registerMatchers(MatchFinder *Finder) { + auto NamespaceMatcher = Options.get("AllowAnonymousNamespace", false) + ? namespaceDecl(unless(isAnonymous())) + : namespaceDecl(); auto GlobalContext = varDecl(hasGlobalStorage(), - hasDeclContext(anyOf(namespaceDecl(), translationUnitDecl()))); + hasDeclContext(anyOf(NamespaceMatcher, translationUnitDecl()))); auto GlobalVariable = varDecl( GlobalContext, diff --git a/clang-tools-extra/docs/clang-tidy/checks/cppcoreguidelines/avoid-non-const-global-variables.rst b/clang-tools-extra/docs/clang-tidy/checks/cppcoreguidelines/avoid-non-const-global-variables.rst index 21c20af6e8107..e2350872c6ece 100644 --- a/clang-tools-extra/docs/clang-tidy/checks/cppcoreguidelines/avoid-non-const-global-variables.rst +++ b/clang-tools-extra/docs/clang-tidy/checks/cppcoreguidelines/avoid-non-const-global-variables.rst @@ -41,3 +41,25 @@ The variables ``a``, ``c``, ``c_ptr1``, ``c_const_ptr`` and ``c_reference`` will all generate warnings since they are either a non-const globally accessible variable, a pointer or a reference providing global access to non-const data or both. + +Options +------- + +.. option:: AllowAnonymousNamespace + + When set to `true` (default is `false`), non-const variables in anonymous namespaces will not generate a warning. + +Example +^^^^^^^ + +.. code-block:: c++ + + namespace { + int counter = 0; + } + + int Increment() { + return ++counter; + } + +will not generate a warning for `counter` if :option:`AllowAnonymousNamespace` is set to `true`. diff --git a/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/avoid-non-const-global-variables.cpp b/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/avoid-non-const-global-variables.cpp index 3ca1029433d22..8956dd414356e 100644 --- a/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/avoid-non-const-global-variables.cpp +++ b/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/avoid-non-const-global-variables.cpp @@ -1,21 +1,30 @@ -// RUN: %check_clang_tidy %s cppcoreguidelines-avoid-non-const-global-variables %t +// RUN: %check_clang_tidy %s -check-suffix=DEFAULT cppcoreguidelines-avoid-non-const-global-variables %t +// RUN: %check_clang_tidy %s -check-suffix=NAMESPACE cppcoreguidelines-avoid-non-const-global-variables %t -- \ +// RUN: -config="{CheckOptions: {cppcoreguidelines-avoid-non-const-global-variables.AllowAnonymousNamespace : 'true'}}" + int nonConstInt = 0; -// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: variable 'nonConstInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-1]]:5: warning: variable 'nonConstInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-2]]:5: warning: variable 'nonConstInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] int &nonConstIntReference = nonConstInt; -// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: variable 'nonConstIntReference' provides global access to a non-const object; consider making the referenced data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-1]]:6: warning: variable 'nonConstIntReference' provides global access to a non-const object; consider making the referenced data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-2]]:6: warning: variable 'nonConstIntReference' provides global access to a non-const object; consider making the referenced data 'const' [cppcoreguidelines-avoid-non-const-global-variables] int *pointerToNonConstInt = &nonConstInt; -// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: variable 'pointerToNonConstInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] -// CHECK-MESSAGES: :[[@LINE-2]]:6: warning: variable 'pointerToNonConstInt' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-1]]:6: warning: variable 'pointerToNonConstInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-2]]:6: warning: variable 'pointerToNonConstInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-3]]:6: warning: variable 'pointerToNonConstInt' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-4]]:6: warning: variable 'pointerToNonConstInt' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] int *const constPointerToNonConstInt = &nonConstInt; -// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: variable 'constPointerToNonConstInt' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-1]]:12: warning: variable 'constPointerToNonConstInt' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-2]]:12: warning: variable 'constPointerToNonConstInt' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] namespace namespace_name { int nonConstNamespaceInt = 0; -// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: variable 'nonConstNamespaceInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-1]]:5: warning: variable 'nonConstNamespaceInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-2]]:5: warning: variable 'nonConstNamespaceInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] const int constNamespaceInt = 0; } // namespace namespace_name @@ -23,7 +32,8 @@ const int constNamespaceInt = 0; const int constInt = 0; const int *pointerToConstInt = &constInt; -// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: variable 'pointerToConstInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-1]]:12: warning: variable 'pointerToConstInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-2]]:12: warning: variable 'pointerToConstInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] const int *const constPointerToConstInt = &constInt; @@ -38,7 +48,8 @@ int function() { namespace { int nonConstAnonymousNamespaceInt = 0; -// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: variable 'nonConstAnonymousNamespaceInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-1]]:5: warning: variable 'nonConstAnonymousNamespaceInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE-NOT: :[[@LINE-2]]:5: warning: variable 'nonConstAnonymousNamespaceInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] } // namespace class DummyClass { @@ -52,28 +63,37 @@ class DummyClass { }; DummyClass nonConstClassInstance; -// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: variable 'nonConstClassInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-1]]:12: warning: variable 'nonConstClassInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-2]]:12: warning: variable 'nonConstClassInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] DummyClass *pointerToNonConstDummyClass = &nonConstClassInstance; -// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: variable 'pointerToNonConstDummyClass' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] -// CHECK-MESSAGES: :[[@LINE-2]]:13: warning: variable 'pointerToNonConstDummyClass' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-1]]:13: warning: variable 'pointerToNonConstDummyClass' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-2]]:13: warning: variable 'pointerToNonConstDummyClass' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-3]]:13: warning: variable 'pointerToNonConstDummyClass' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-4]]:13: warning: variable 'pointerToNonConstDummyClass' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] DummyClass &referenceToNonConstDummyClass = nonConstClassInstance; -// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: variable 'referenceToNonConstDummyClass' provides global access to a non-const object; consider making the referenced data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-1]]:13: warning: variable 'referenceToNonConstDummyClass' provides global access to a non-const object; consider making the referenced data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-2]]:13: warning: variable 'referenceToNonConstDummyClass' provides global access to a non-const object; consider making the referenced data 'const' [cppcoreguidelines-avoid-non-const-global-variables] int *nonConstPointerToMember = &nonConstClassInstance.nonConstPublicMemberVariable; -// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: variable 'nonConstPointerToMember' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] -// CHECK-MESSAGES: :[[@LINE-2]]:6: warning: variable 'nonConstPointerToMember' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-1]]:6: warning: variable 'nonConstPointerToMember' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-2]]:6: warning: variable 'nonConstPointerToMember' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-3]]:6: warning: variable 'nonConstPointerToMember' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-4]]:6: warning: variable 'nonConstPointerToMember' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] int *const constPointerToNonConstMember = &nonConstClassInstance.nonConstPublicMemberVariable; -// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: variable 'constPointerToNonConstMember' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-1]]:12: warning: variable 'constPointerToNonConstMember' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-2]]:12: warning: variable 'constPointerToNonConstMember' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] const DummyClass constClassInstance; DummyClass *const constPointerToNonConstDummyClass = &nonConstClassInstance; -// CHECK-MESSAGES: :[[@LINE-1]]:19: warning: variable 'constPointerToNonConstDummyClass' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-1]]:19: warning: variable 'constPointerToNonConstDummyClass' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-2]]:19: warning: variable 'constPointerToNonConstDummyClass' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] const DummyClass *nonConstPointerToConstDummyClass = &constClassInstance; -// CHECK-MESSAGES: :[[@LINE-1]]:19: warning: variable 'nonConstPointerToConstDummyClass' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-1]]:19: warning: variable 'nonConstPointerToConstDummyClass' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-2]]:19: warning: variable 'nonConstPointerToConstDummyClass' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] const DummyClass *const constPointerToConstDummyClass = &constClassInstance; @@ -83,7 +103,8 @@ const DummyClass &constReferenceToDummyClass = constClassInstance; namespace namespace_name { DummyClass nonConstNamespaceClassInstance; -// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: variable 'nonConstNamespaceClassInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-1]]:12: warning: variable 'nonConstNamespaceClassInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-2]]:12: warning: variable 'nonConstNamespaceClassInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] const DummyClass constDummyClassInstance; } // namespace namespace_name @@ -95,22 +116,28 @@ enum DummyEnum { }; DummyEnum nonConstDummyEnumInstance = DummyEnum::first; -// CHECK-MESSAGES: :[[@LINE-1]]:11: warning: variable 'nonConstDummyEnumInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-1]]:11: warning: variable 'nonConstDummyEnumInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-2]]:11: warning: variable 'nonConstDummyEnumInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] DummyEnum *pointerToNonConstDummyEnum = &nonConstDummyEnumInstance; -// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: variable 'pointerToNonConstDummyEnum' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] -// CHECK-MESSAGES: :[[@LINE-2]]:12: warning: variable 'pointerToNonConstDummyEnum' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-1]]:12: warning: variable 'pointerToNonConstDummyEnum' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-2]]:12: warning: variable 'pointerToNonConstDummyEnum' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-3]]:12: warning: variable 'pointerToNonConstDummyEnum' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-4]]:12: warning: variable 'pointerToNonConstDummyEnum' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] DummyEnum &referenceToNonConstDummyEnum = nonConstDummyEnumInstance; -// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: variable 'referenceToNonConstDummyEnum' provides global access to a non-const object; consider making the referenced data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-1]]:12: warning: variable 'referenceToNonConstDummyEnum' provides global access to a non-const object; consider making the referenced data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-2]]:12: warning: variable 'referenceToNonConstDummyEnum' provides global access to a non-const object; consider making the referenced data 'const' [cppcoreguidelines-avoid-non-const-global-variables] DummyEnum *const constPointerToNonConstDummyEnum = &nonConstDummyEnumInstance; -// CHECK-MESSAGES: :[[@LINE-1]]:18: warning: variable 'constPointerToNonConstDummyEnum' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-DEFAULT: [[@LINE-1]]:18: warning: variable 'constPointerToNonConstDummyEnum' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] +// CHECK-MESSAGES-NAMESPACE: [[@LINE-2]]:18: warning: variable 'constPointerToNonConstDummyEnum' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables] const DummyEnum constDummyEnumInstance = DummyEnum::first; const DummyEnum *nonConstPointerToConstDummyEnum = &constDummyEnumInstance; -// CHECK-MESSAGES: :[[@LINE-1]]:18: warning: variable 'nonConstPointerToConstDummyEnum' is non-const and globally accessible, consider making it const [c... [truncated] `````````` </details> https://github.com/llvm/llvm-project/pull/93827 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
