[clang-tools-extra] [clang-tidy] Option to ignore anonymous namespaces in avoid-non-const-global-variables (PR #93827)
Pascal Jungblut via cfe-commits
cfe-commits at lists.llvm.org
Fri May 31 02:45:30 PDT 2024
https://github.com/pascalj updated https://github.com/llvm/llvm-project/pull/93827
>From abe862b84fd6915edb281a21e49f1be2aac3a626 Mon Sep 17 00:00:00 2001
From: Pascal Jungblut <mail at pascalj.de>
Date: Thu, 30 May 2024 14:28:50 +0200
Subject: [PATCH] Add option to ignore anonymous namespaces in
avoid-non-const-global-variables
---
.../AvoidNonConstGlobalVariablesCheck.cpp | 19 +++++++++++++---
.../AvoidNonConstGlobalVariablesCheck.h | 7 ++++--
clang-tools-extra/docs/ReleaseNotes.rst | 5 +++++
.../avoid-non-const-global-variables.rst | 8 +++++++
.../avoid-non-const-global-variables.cpp | 22 ++++++++++++++-----
5 files changed, 51 insertions(+), 10 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/AvoidNonConstGlobalVariablesCheck.cpp b/clang-tools-extra/clang-tidy/cppcoreguidelines/AvoidNonConstGlobalVariablesCheck.cpp
index ee17b0e014288..a97ec9fe3fe3d 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"
@@ -15,13 +14,23 @@ using namespace clang::ast_matchers;
namespace clang::tidy::cppcoreguidelines {
+AvoidNonConstGlobalVariablesCheck::AvoidNonConstGlobalVariablesCheck(
+ StringRef Name, ClangTidyContext *Context)
+ : ClangTidyCheck(Name, Context),
+ AllowInternalLinkage(Options.get("AllowInternalLinkage", false)) {}
+
void AvoidNonConstGlobalVariablesCheck::registerMatchers(MatchFinder *Finder) {
+ auto NamespaceMatcher = AllowInternalLinkage
+ ? namespaceDecl(unless(isAnonymous()))
+ : namespaceDecl();
auto GlobalContext =
varDecl(hasGlobalStorage(),
- hasDeclContext(anyOf(namespaceDecl(), translationUnitDecl())));
+ hasDeclContext(anyOf(NamespaceMatcher, translationUnitDecl())));
auto GlobalVariable = varDecl(
GlobalContext,
+ AllowInternalLinkage ? varDecl(unless(isStaticStorageClass()))
+ : varDecl(),
unless(anyOf(
isConstexpr(), hasType(isConstQualified()),
hasType(referenceType())))); // References can't be changed, only the
@@ -43,7 +52,6 @@ void AvoidNonConstGlobalVariablesCheck::registerMatchers(MatchFinder *Finder) {
void AvoidNonConstGlobalVariablesCheck::check(
const MatchFinder::MatchResult &Result) {
-
if (const auto *Variable =
Result.Nodes.getNodeAs<VarDecl>("non-const_variable")) {
diag(Variable->getLocation(), "variable %0 is non-const and globally "
@@ -63,4 +71,9 @@ void AvoidNonConstGlobalVariablesCheck::check(
}
}
+void AvoidNonConstGlobalVariablesCheck::storeOptions(
+ ClangTidyOptions::OptionMap &Opts) {
+ Options.store(Opts, "AllowInternalLinkage", AllowInternalLinkage);
+}
+
} // namespace clang::tidy::cppcoreguidelines
diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/AvoidNonConstGlobalVariablesCheck.h b/clang-tools-extra/clang-tidy/cppcoreguidelines/AvoidNonConstGlobalVariablesCheck.h
index e816ca9b47d41..a912763489db9 100644
--- a/clang-tools-extra/clang-tidy/cppcoreguidelines/AvoidNonConstGlobalVariablesCheck.h
+++ b/clang-tools-extra/clang-tidy/cppcoreguidelines/AvoidNonConstGlobalVariablesCheck.h
@@ -20,10 +20,13 @@ namespace clang::tidy::cppcoreguidelines {
/// http://clang.llvm.org/extra/clang-tidy/checks/cppcoreguidelines/avoid-non-const-global-variables.html
class AvoidNonConstGlobalVariablesCheck : public ClangTidyCheck {
public:
- AvoidNonConstGlobalVariablesCheck(StringRef Name, ClangTidyContext *Context)
- : ClangTidyCheck(Name, Context) {}
+ AvoidNonConstGlobalVariablesCheck(StringRef Name, ClangTidyContext *Context);
void registerMatchers(ast_matchers::MatchFinder *Finder) override;
void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+ void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
+
+private:
+ const bool AllowInternalLinkage;
};
} // namespace clang::tidy::cppcoreguidelines
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 4f674d1a4d556..4db476718f775 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -250,6 +250,11 @@ Changes in existing checks
<clang-tidy/checks/bugprone/use-after-move>` check to also handle
calls to ``std::forward``.
+- Improved :doc:`cppcoreguidelines-avoid-non-const-global-variables
+ <clang-tidy/checks/cppcoreguidelines/avoid-non-const-global-variables>` check
+ with a new option `AllowInternalLinkage` to disable the warning for variables
+ with internal linkage.
+
- Improved :doc:`cppcoreguidelines-missing-std-forward
<clang-tidy/checks/cppcoreguidelines/missing-std-forward>` check by no longer
giving false positives for deleted functions, by fixing false negatives when only
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..8da284ca13e3d 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 +41,11 @@ 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:: AllowInternalLinkage
+
+ When set to `true`, static non-const variables and variables in anonymous
+ namespaces will not generate a warning. The default value is `false`.
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..334332def216f 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
@@ -1,4 +1,6 @@
-// RUN: %check_clang_tidy %s cppcoreguidelines-avoid-non-const-global-variables %t
+// RUN: %check_clang_tidy %s -check-suffixes=,DEFAULT cppcoreguidelines-avoid-non-const-global-variables %t
+// RUN: %check_clang_tidy %s -check-suffixes=,INTERNAL-LINKAGE cppcoreguidelines-avoid-non-const-global-variables %t -- \
+// RUN: -config="{CheckOptions: {cppcoreguidelines-avoid-non-const-global-variables.AllowInternalLinkage : '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]
@@ -38,9 +40,16 @@ 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-INTERNAL-LINKAGE-NOT: :[[@LINE-2]]:5: warning: variable 'nonConstAnonymousNamespaceInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
} // namespace
+static int nonConstStaticInt = 0;
+// CHECK-MESSAGES-DEFAULT: :[[@LINE-1]]:12: warning: variable 'nonConstStaticInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-MESSAGES-INTERNAL-LINKAGE-NOT: :[[@LINE-2]]:12: warning: variable 'nonConstStaticInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
+
+static const int constStaticInt = 0;
+
class DummyClass {
public:
int nonConstPublicMemberVariable = 0;
@@ -126,7 +135,8 @@ const DummyEnum constNamespaceEnumInstance = DummyEnum::first;
namespace {
DummyEnum nonConstAnonymousNamespaceEnumInstance = DummyEnum::first;
}
-// CHECK-MESSAGES: :[[@LINE-2]]:11: warning: variable 'nonConstAnonymousNamespaceEnumInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-MESSAGES-DEFAULT: :[[@LINE-2]]:11: warning: variable 'nonConstAnonymousNamespaceEnumInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-MESSAGES-INTERNAL-LINKAGE-NOT: :[[@LINE-2]]:11: warning: variable 'nonConstAnonymousNamespaceEnumInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
// CHECKING FOR NON-CONST GLOBAL STRUCT ///////////////////////////////////////
struct DummyStruct {
@@ -169,7 +179,8 @@ const DummyStruct constNamespaceDummyStructInstance;
namespace {
DummyStruct nonConstAnonymousNamespaceStructInstance;
}
-// CHECK-MESSAGES: :[[@LINE-2]]:13: warning: variable 'nonConstAnonymousNamespaceStructInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-MESSAGES-DEFAULT: :[[@LINE-2]]:13: warning: variable 'nonConstAnonymousNamespaceStructInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-MESSAGES-INTERNAL-LINKAGE-NOT: :[[@LINE-2]]:11: warning: variable 'nonConstAnonymousNamespaceEnumInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
// CHECKING FOR NON-CONST GLOBAL UNION ////////////////////////////////////////
union DummyUnion {
@@ -209,7 +220,8 @@ const DummyUnion constNamespaceDummyUnionInstance = {0x0};
namespace {
DummyUnion nonConstAnonymousNamespaceUnionInstance = {0x0};
}
-// CHECK-MESSAGES: :[[@LINE-2]]:12: warning: variable 'nonConstAnonymousNamespaceUnionInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-MESSAGES-DEFAULT: :[[@LINE-2]]:12: warning: variable 'nonConstAnonymousNamespaceUnionInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-MESSAGES-INTERNAL-LINKAGE-NOT: :[[@LINE-3]]:12: warning: variable 'nonConstAnonymousNamespaceUnionInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
// CHECKING FOR NON-CONST GLOBAL FUNCTION POINTER /////////////////////////////
int dummyFunction() {
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