[clang-tidy] cppcoreguidelines-avoid-non-const-global-variables: add fixes to checks

[mgartmann]

Summary

I added fixes to the existing checks of cppcoreguidelines-avoid-non-const-global-variables.

To fix the non-const_variable case, it utilizes QualType::addConst to make the non-const type constant.

For the indirection_to_non-const case, for the sake of simplicity of this check, the const keyword is simply inserted at the variable declaration's beginning. If someone knows a more elegant solution to this, I am happy to adapt it.

Thanks in advance for any feedback!

[mgartmann]

• Renamed printCleanedType() to cleanType()
• Extended cleanType() to also remove (anonymous) from a type
• Made hasSpaceAfterType() more error-robust.

[mgartmann]

Fixed one-off error.

[mgartmann]

Replaced string comparison to check if a character is a space with std::isspace().
Added test case for this scenario.

[mgartmann]

Friendly ping, any feedback would be appreciated :)

[mgartmann]

Dear reviewers,

Since this work was conducted as part of a Bachelor's thesis, which has to be
handed in on the 18th of June, 2021, we wanted to add a friendly ping to this
patch.

It would make us, the thesis team, proud to state that some of our work was
accepted and included into the LLVM project.

Therefore, we wanted to ask if we can further improve anything in this patch
for it to get a LGTM?

Thanks a lot in advance!
Yours faithfully,
Fabian & Marco

clang-tools-extra/clang-tidy/cppcoreguidelines/AvoidNonConstGlobalVariablesCheck.h

 //===--- AvoidNonConstGlobalVariablesCheck.h - clang-tidy -------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CPPCOREGUIDELINES_AVOIDNONCONSTGLOBALVARIABLESCHECK_H
 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CPPCOREGUIDELINES_AVOIDNONCONSTGLOBALVARIABLESCHECK_H
 
 #include "../ClangTidyCheck.h"
+#include <string>
 
 namespace clang {
 namespace tidy {
 namespace cppcoreguidelines {
 
 /// Non-const global variables hide dependencies and make the dependencies
 /// subject to unpredictable changes.
 ///
 /// For the user-facing documentation see:
 /// http://clang.llvm.org/extra/clang-tidy/checks/cppcoreguidelines-avoid-non-const-global-variables.html
 class AvoidNonConstGlobalVariablesCheck : public ClangTidyCheck {
+  std::string generateReplacementString(
+      const ast_matchers::MatchFinder::MatchResult &Result,
+      const VarDecl &Variablee) const;
+
+  bool hasSpaceAfterType(const ast_matchers::MatchFinder::MatchResult &Result,
+                         const VarDecl &Variable,
+                         const std::string &NonConstType) const;
+
+  CharSourceRange generateReplacementRange(const VarDecl &Variable) const;
+
+  std::string cleanType(const QualType &Type) const;
+
 public:
   AvoidNonConstGlobalVariablesCheck(StringRef Name, ClangTidyContext *Context)
       : ClangTidyCheck(Name, Context) {}
   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
 };
 
 } // namespace cppcoreguidelines
 } // namespace tidy
 } // namespace clang
 
 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CPPCOREGUIDELINES_AVOIDNONCONSTGLOBALVARIABLESCHECK_H

clang-tools-extra/clang-tidy/cppcoreguidelines/AvoidNonConstGlobalVariablesCheck.cpp

 //===--- AvoidNonConstGlobalVariablesCheck.cpp - clang-tidy ---------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "AvoidNonConstGlobalVariablesCheck.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/ASTMatchers/ASTMatchFinder.h"
 #include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/Lex/Lexer.h"
 
 using namespace clang::ast_matchers;
 
 namespace clang {
 namespace tidy {
 namespace cppcoreguidelines {
 
 namespace {
Finder->addMatcher(GlobalPointerToNonConst.bind("indirection_to_non-const"),
                      this);
 }
 
 void AvoidNonConstGlobalVariablesCheck::check(
     const MatchFinder::MatchResult &Result) {
 
   if (const auto *Variable =
           Result.Nodes.getNodeAs<VarDecl>("non-const_variable")) {
+
+    auto ReplacementRange = generateReplacementRange(*Variable);
+    auto Replacement = generateReplacementString(Result, *Variable);
+
     diag(Variable->getLocation(), "variable %0 is non-const and globally "
                                   "accessible, consider making it const")
-        << Variable; // FIXME: Add fix-it hint to Variable
+        << Variable
+        << FixItHint::CreateReplacement(ReplacementRange, Replacement);
+
     // Don't return early, a non-const variable may also be a pointer or
     // reference to non-const data.
   }
 
   if (const auto *VD =
           Result.Nodes.getNodeAs<VarDecl>("indirection_to_non-const")) {
     diag(VD->getLocation(),
          "variable %0 provides global access to a non-const object; consider "
          "making the %select{referenced|pointed-to}1 data 'const'")
-        << VD
-        << VD->getType()->isPointerType(); // FIXME: Add fix-it hint to Variable
-  }
+        << VD << VD->getType()->isPointerType()
+        << FixItHint::CreateInsertion(VD->getBeginLoc(), "const ");
+  }
+}
+
+/// Makes the provided type constant and converts it to a string.
+/// If the current type sticks to the variable name as in the example below, a
+/// space is inserted:
+//
+/// \code
+/// int *y = &x;
+///     ^^
+/// \endcode
+///
+/// \returns string representation of the constant type of \p Variable.
+std::string AvoidNonConstGlobalVariablesCheck::generateReplacementString(
+    const MatchFinder::MatchResult &Result, const VarDecl &Variable) const {
+
+  auto Type = Variable.getType();
+  bool HasSpace = hasSpaceAfterType(Result, Variable, cleanType(Type));
+  Type.addConst();
+  return cleanType(Type) + (HasSpace ? "" : " ");
+
+bool AvoidNonConstGlobalVariablesCheck::hasSpaceAfterType(
+    const MatchFinder::MatchResult &Result, const VarDecl &Variable,
+    const std::string &NonConstType) const {
+
+  StringRef VariableText = Lexer::getSourceText(
+      CharSourceRange::getTokenRange(Variable.getSourceRange()),
+      *Result.SourceManager, getLangOpts());
+
+  /// Check to make the function error-robust in case \c NonConstType.length()
+  /// exceeds \c VariableText length. This would occure if the \c PrintingPolicy
+  /// used in \c printCleanedType did not remove all superfluous type
+  /// information. As a fallback, it is assumed that the type is not followed by
+  /// a space in the source code.
+  if (NonConstType.length() > VariableText.str().length()) {
+    llvm::errs() << "Checking for space failed: the type's effective "
+                    "length is greater than the variable declaration.";
+    return false;
+  }
+
+  return VariableText.str().at(NonConstType.length()) == ' ';
+}
+
+CharSourceRange AvoidNonConstGlobalVariablesCheck::generateReplacementRange(
+    const VarDecl &Variable) const {
+
+  auto TypeBeginLoc = Variable.getBeginLoc();
+
+  auto TypeEndLoc =
+      TypeBeginLoc.getLocWithOffset(cleanType(Variable.getType()).length());
+
+  return CharSourceRange::getCharRange(TypeBeginLoc, TypeEndLoc);
+}
+
+/// Creates a string representation of \p Type and suppresses the \c class
+/// keyword in a class instance's type. Also, on unnamed/anonymous types, the
+/// tag location and the \c unnamed or \c anonymous keyword are removed from the
+/// type description. If this would not be done, those keywords would be
+/// inserted into the source code as part of the \c FixItHint replacement.
+std::string
+AvoidNonConstGlobalVariablesCheck::cleanType(const QualType &Type) const {
+
+  /// \c PrintingPolicy suppresses the "class" keyword in a class
+  /// instance's type and locations of anonymous tags.
+  PrintingPolicy PrintingPolicy{getLangOpts()};
+  PrintingPolicy.AnonymousTagLocations = false;
+  std::string PolicyCleanedType = Type.getAsString(PrintingPolicy);
+
+  auto StringsToErase = SmallVector<std::string>{" (unnamed)", " (anonymous)"};
+
+  for (std::string StringToErase : StringsToErase) {
+    size_t StartPositionToErase = PolicyCleanedType.find(StringToErase);
+    if (StartPositionToErase == std::string::npos)
+      continue;
+    PolicyCleanedType.erase(StartPositionToErase, StringToErase.length());
+  }
+
+  return PolicyCleanedType;
 }
 
 } // namespace cppcoreguidelines
 } // namespace tidy
 } // namespace clang

clang-tools-extra/docs/ReleaseNotes.rst

 
 - Improved :doc:`readability-uniqueptr-delete-release
   <clang-tidy/checks/readability-uniqueptr-delete-release>` check.
 
   Added an option to choose whether to refactor by calling the ``reset`` member
   function or assignment to ``nullptr``.
   Added support for pointers to ``std::unique_ptr``.
 
+- Improved :doc:`cppcoreguidelines-avoid-non-const-global-variables
+  <clang-tidy/checks/cppcoreguidelines-avoid-non-const-global-variables` check.
+
+  Added ``FixItHints`` to the checks which make the problematic variables, pointers 
+  and references constant.
+
 Removed checks
 ^^^^^^^^^^^^^^
 
 - The readability-deleted-default check has been removed.
   
   The clang warning `Wdefaulted-function-deleted
   <https://clang.llvm.org/docs/DiagnosticsReference.html#wdefaulted-function-deleted>`_
   will diagnose the same issues and is enabled by default.

clang-tools-extra/docs/clang-tidy/checks/cppcoreguidelines-avoid-non-const-global-variables.rst

.. code-block:: c++
     private:
         char h = 0;
     };
 
 Variables: ``a``, ``c``, ``c_ptr1``, ``c_ptr2``, ``c_const_ptr`` and
 ``c_reference``, will all generate warnings since they are either:
 a globally accessible variable and non-const, a pointer or reference providing
 global access to non-const data or both.
+
+The check also provides fixes that make the problematic variables, pointers and 
+references constant.

clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines-avoid-non-const-global-variables.cpp

 // RUN: %check_clang_tidy %s cppcoreguidelines-avoid-non-const-global-variables %t
 
 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-FIXES: const int nonConstInt = 0;
 
 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-FIXES: const int &nonConstIntReference = nonConstInt;
 
 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-FIXES: const int *const pointerToNonConstInt = &nonConstInt;
 
 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-FIXES: const int *const constPointerToNonConstInt = &nonConstInt;
 
 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-FIXES: const int nonConstNamespaceInt = 0;
 
 const int constNamespaceInt = 0;
 } // namespace namespace_name
 
 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-FIXES: const int *const pointerToConstInt = &constInt;
 
 const int *const constPointerToConstInt = &constInt;
 
 const int &constReferenceToConstInt = constInt;
 
 constexpr int constexprInt = 0;
 
 int function() {
   int nonConstReturnValue = 0;
   return nonConstReturnValue;
 }
 
 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-FIXES: const int nonConstAnonymousNamespaceInt = 0;
 } // namespace
 
 class DummyClass {
 public:
   int nonConstPublicMemberVariable = 0;
   const int constPublicMemberVariable = 0;
 
 private:
   int nonConstPrivateMemberVariable = 0;
   const int constPrivateMemberVariable = 0;
 };
 
 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-FIXES: const DummyClass nonConstClassInstance;
 
 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-FIXES: const DummyClass *const pointerToNonConstDummyClass = &nonConstClassInstance;
 
 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-FIXES: const DummyClass &referenceToNonConstDummyClass = nonConstClassInstance;
 
 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-FIXES: const int *const nonConstPointerToMember = &nonConstClassInstance.nonConstPublicMemberVariable;
+
 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-FIXES: const int *const constPointerToNonConstMember = &nonConstClassInstance.nonConstPublicMemberVariable;
 
 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-FIXES: const DummyClass *const constPointerToNonConstDummyClass = &nonConstClassInstance;
 
 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-FIXES: const DummyClass *const nonConstPointerToConstDummyClass = &constClassInstance;
 
 const DummyClass *const constPointerToConstDummyClass = &constClassInstance;
 
 const int *const constPointerToConstMember = &constClassInstance.nonConstPublicMemberVariable;
 
 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-FIXES: const DummyClass nonConstNamespaceClassInstance;
 
 const DummyClass constDummyClassInstance;
 } // namespace namespace_name
 
 // CHECKING FOR NON-CONST GLOBAL ENUM /////////////////////////////////////////
 enum DummyEnum {
   first,
   second
 };
 
 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-FIXES: const DummyEnum nonConstDummyEnumInstance = DummyEnum::first;
 
 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-FIXES: const DummyEnum *const pointerToNonConstDummyEnum = &nonConstDummyEnumInstance;
 
 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-FIXES: const DummyEnum &referenceToNonConstDummyEnum = nonConstDummyEnumInstance;
 
 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-FIXES: const DummyEnum *const constPointerToNonConstDummyEnum = &nonConstDummyEnumInstance;
 
 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 [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-FIXES: const DummyEnum *const nonConstPointerToConstDummyEnum = &constDummyEnumInstance;
 
 const DummyEnum *const constPointerToConstDummyEnum = &constDummyEnumInstance;
 
 const DummyEnum &referenceToConstDummyEnum = constDummyEnumInstance;
 
 namespace namespace_name {
 DummyEnum nonConstNamespaceEnumInstance = DummyEnum::first;
 // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: variable 'nonConstNamespaceEnumInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-FIXES: const DummyEnum nonConstNamespaceEnumInstance = DummyEnum::first;
 
 const DummyEnum constNamespaceEnumInstance = DummyEnum::first;
 } // namespace namespace_name
 
 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-FIXES: const DummyEnum nonConstAnonymousNamespaceEnumInstance = DummyEnum::first;
 
 // CHECKING FOR NON-CONST GLOBAL STRUCT ///////////////////////////////////////
+struct {
+  // CHECK-FIXES: const struct {
+public:
+  int structIntElement = 0;
+  const int constStructIntElement = 0;
+
+private:
+  int privateStructIntElement = 0;
+} nonConstUnnamedStructInstance{};
+// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: variable 'nonConstUnnamedStructInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
+
 struct DummyStruct {
+  // CHECK-FIXES: const struct DummyStruct {
 public:
   int structIntElement = 0;
   const int constStructIntElement = 0;
 
 private:
   int privateStructIntElement = 0;
-};
+} directNonConstDummyStructInstance{};
+// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: variable 'directNonConstDummyStructInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
 
 DummyStruct nonConstDummyStructInstance;
 // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: variable 'nonConstDummyStructInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-FIXES: const DummyStruct nonConstDummyStructInstance;
 
 DummyStruct *pointerToNonConstDummyStruct = &nonConstDummyStructInstance;
 // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: variable 'pointerToNonConstDummyStruct' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
 // CHECK-MESSAGES: :[[@LINE-2]]:14: warning: variable 'pointerToNonConstDummyStruct' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-FIXES: const DummyStruct *const pointerToNonConstDummyStruct = &nonConstDummyStructInstance;
 
 DummyStruct &referenceToNonConstDummyStruct = nonConstDummyStructInstance;
 // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: variable 'referenceToNonConstDummyStruct' provides global access to a non-const object; consider making the referenced data 'const' [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-FIXES: const DummyStruct &referenceToNonConstDummyStruct = nonConstDummyStructInstance;
+
 DummyStruct *const constPointerToNonConstDummyStruct = &nonConstDummyStructInstance;
 // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: variable 'constPointerToNonConstDummyStruct' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-FIXES: const DummyStruct *const constPointerToNonConstDummyStruct = &nonConstDummyStructInstance;
 
 const DummyStruct constDummyStructInstance;
 
 const DummyStruct *nonConstPointerToConstDummyStruct = &constDummyStructInstance;
 // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: variable 'nonConstPointerToConstDummyStruct' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-FIXES: const DummyStruct *const nonConstPointerToConstDummyStruct = &constDummyStructInstance;
 
 const DummyStruct *const constPointerToConstDummyStruct = &constDummyStructInstance;
 
 const DummyStruct &referenceToConstDummyStruct = constDummyStructInstance;
 
 namespace namespace_name {
 DummyStruct nonConstNamespaceDummyStructInstance;
 // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: variable 'nonConstNamespaceDummyStructInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-FIXES: const DummyStruct nonConstNamespaceDummyStructInstance;
 
 const DummyStruct constNamespaceDummyStructInstance;
 } // namespace namespace_name
 
 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-FIXES: const DummyStruct nonConstAnonymousNamespaceStructInstance;
 
 // CHECKING FOR NON-CONST GLOBAL UNION ////////////////////////////////////////
 union DummyUnion {
   int unionInteger;
   char unionChar;
 };
 
 DummyUnion nonConstUnionIntInstance = {0x0};
 // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: variable 'nonConstUnionIntInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-FIXES: const DummyUnion nonConstUnionIntInstance = {0x0};
 
 DummyUnion *nonConstPointerToNonConstUnionInt = &nonConstUnionIntInstance;
 // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: variable 'nonConstPointerToNonConstUnionInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
 // CHECK-MESSAGES: :[[@LINE-2]]:13: warning: variable 'nonConstPointerToNonConstUnionInt' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-FIXES: const DummyUnion *const nonConstPointerToNonConstUnionInt = &nonConstUnionIntInstance;
 
 DummyUnion *const constPointerToNonConstUnionInt = &nonConstUnionIntInstance;
 // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: variable 'constPointerToNonConstUnionInt' provides global access to a non-const object; consider making the pointed-to data 'const' [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-FIXES: const DummyUnion *const constPointerToNonConstUnionInt = &nonConstUnionIntInstance;
 
 DummyUnion &referenceToNonConstUnionInt = nonConstUnionIntInstance;
 // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: variable 'referenceToNonConstUnionInt' provides global access to a non-const object; consider making the referenced data 'const' [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-FIXES: const DummyUnion &referenceToNonConstUnionInt = nonConstUnionIntInstance;
 
 const DummyUnion constUnionIntInstance = {0x0};
 
 const DummyUnion *nonConstPointerToConstUnionInt = &constUnionIntInstance;
 // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: variable 'nonConstPointerToConstUnionInt' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-FIXES: const DummyUnion *const nonConstPointerToConstUnionInt = &constUnionIntInstance;
 
 const DummyUnion *const constPointerToConstUnionInt = &constUnionIntInstance;
 
 const DummyUnion &referenceToConstUnionInt = constUnionIntInstance;
 
 namespace namespace_name {
 DummyUnion nonConstNamespaceDummyUnionInstance;
 // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: variable 'nonConstNamespaceDummyUnionInstance' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-FIXES: const DummyUnion nonConstNamespaceDummyUnionInstance;
 
 const DummyUnion constNamespaceDummyUnionInstance = {0x0};
 } // namespace namespace_name
 
 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-FIXES: const DummyUnion nonConstAnonymousNamespaceUnionInstance = {0x0};
 
 // CHECKING FOR NON-CONST GLOBAL FUNCTION POINTER /////////////////////////////
 int dummyFunction() {
   return 0;
 }
 
 typedef int (*functionPointer)();
 functionPointer fp1 = &dummyFunction;
 // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: variable 'fp1' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-FIXES: const functionPointer fp1 = &dummyFunction;
 
 typedef int (*const functionConstPointer)();
 functionPointer fp2 = &dummyFunction;
 // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: variable 'fp2' is non-const and globally accessible, consider making it const [cppcoreguidelines-avoid-non-const-global-variables]
+// CHECK-FIXES: const functionPointer fp2 = &dummyFunction;
 
 // CHECKING FOR NON-CONST GLOBAL TEMPLATE VARIABLE ////////////////////////////
 template <class T>
 constexpr T templateVariable = T(0L);
 
 // CHECKING AGAINST FALSE POSITIVES INSIDE FUNCTION SCOPE /////////////////////
 int main() {
   for (int i = 0; i < 3; ++i) {
     static int staticNonConstLoopVariable = 42;
     int nonConstLoopVariable = 42;
     nonConstInt = nonConstLoopVariable + i + staticNonConstLoopVariable;
   }
 }