[clang-tidy] add fixhint for misc-use-internal-linkage (llvm#96203)

Author: HerrCai0907

clang-tools-extra/clang-tidy/misc/UseInternalLinkageCheck.cpp

@@ -18,6 +18,26 @@
 
 using namespace clang::ast_matchers;
 
+namespace clang::tidy {
+
+template <>
+struct OptionEnumMapping<misc::UseInternalLinkageCheck::FixModeKind> {
+  static llvm::ArrayRef<
+      std::pair<misc::UseInternalLinkageCheck::FixModeKind, StringRef>>
+  getEnumMapping() {
+    static constexpr std::pair<misc::UseInternalLinkageCheck::FixModeKind,
+                               StringRef>
+        Mapping[] = {
+            {misc::UseInternalLinkageCheck::FixModeKind::None, "None"},
+            {misc::UseInternalLinkageCheck::FixModeKind::UseStatic,
+             "UseStatic"},
+        };
+    return {Mapping};
+  }
+};
+
+} // namespace clang::tidy
+
 namespace clang::tidy::misc {
 
 namespace {
@@ -57,6 +77,16 @@ AST_POLYMORPHIC_MATCHER(isExternStorageClass,
 
 } // namespace
 
+UseInternalLinkageCheck::UseInternalLinkageCheck(StringRef Name,
+                                                 ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context),
+      HeaderFileExtensions(Context->getHeaderFileExtensions()),
+      FixMode(Options.get("FixMode", FixModeKind::UseStatic)) {}
+
+void UseInternalLinkageCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+  Options.store(Opts, "FixMode", FixMode);
+}
+
 void UseInternalLinkageCheck::registerMatchers(MatchFinder *Finder) {
   auto Common =
       allOf(isFirstDecl(), isAllRedeclsInMainFile(HeaderFileExtensions),
@@ -82,11 +112,21 @@ static constexpr StringRef Message =
 
 void UseInternalLinkageCheck::check(const MatchFinder::MatchResult &Result) {
   if (const auto *FD = Result.Nodes.getNodeAs<FunctionDecl>("fn")) {
-    diag(FD->getLocation(), Message) << "function" << FD;
+    DiagnosticBuilder DB = diag(FD->getLocation(), Message) << "function" << FD;
+    SourceLocation FixLoc = FD->getTypeSpecStartLoc();
+    if (FixLoc.isInvalid() || FixLoc.isMacroID())
+      return;
+    if (FixMode == FixModeKind::UseStatic)
+      DB << FixItHint::CreateInsertion(FixLoc, "static ");
     return;
   }
   if (const auto *VD = Result.Nodes.getNodeAs<VarDecl>("var")) {
-    diag(VD->getLocation(), Message) << "variable" << VD;
+    DiagnosticBuilder DB = diag(VD->getLocation(), Message) << "variable" << VD;
+    SourceLocation FixLoc = VD->getTypeSpecStartLoc();
+    if (FixLoc.isInvalid() || FixLoc.isMacroID())
+      return;
+    if (FixMode == FixModeKind::UseStatic)
+      DB << FixItHint::CreateInsertion(FixLoc, "static ");
     return;
   }
   llvm_unreachable("");

clang-tools-extra/clang-tidy/misc/UseInternalLinkageCheck.h

@@ -20,17 +20,22 @@ namespace clang::tidy::misc {
 /// http://clang.llvm.org/extra/clang-tidy/checks/misc/use-internal-linkage.html
 class UseInternalLinkageCheck : public ClangTidyCheck {
 public:
-  UseInternalLinkageCheck(StringRef Name, ClangTidyContext *Context)
-      : ClangTidyCheck(Name, Context),
-        HeaderFileExtensions(Context->getHeaderFileExtensions()) {}
+  UseInternalLinkageCheck(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;
   std::optional<TraversalKind> getCheckTraversalKind() const override {
     return TK_IgnoreUnlessSpelledInSource;
   }
 
+  enum class FixModeKind {
+    None,
+    UseStatic,
+  };
+
 private:
   FileExtensionsSet HeaderFileExtensions;
+  FixModeKind FixMode;
 };
 
 } // namespace clang::tidy::misc

clang-tools-extra/docs/clang-tidy/checks/misc/use-internal-linkage.rst

@@ -25,3 +25,16 @@ Example:
   }
   // already declared as extern
   extern int v2;
+
+Options
+-------
+
+.. option:: FixMode
+
+  Selects what kind of a fix the check should provide.
+
+  ``None``
+    Don't fix automatically.
+
+  ``UseStatic``
+    Add ``static`` for internal linkage variable and function.

clang-tools-extra/test/clang-tidy/checkers/misc/use-internal-linkage-fix-mode-none.cpp

@@ -0,0 +1,10 @@
+// RUN: %check_clang_tidy %s misc-use-internal-linkage %t -- \
+// RUN:   -config="{CheckOptions: {misc-use-internal-linkage.FixMode: 'None'}}"  -- -I%S/Inputs/use-internal-linkage
+
+void func() {}
+// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function 'func'
+// CHECK-FIXES-NOT: static void func() {}
+
+int global;
+// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: variable 'global'
+// CHECK-FIXES-NOT: static int global;

clang-tools-extra/test/clang-tidy/checkers/misc/use-internal-linkage-func.cpp

@@ -1,16 +1,21 @@
 // RUN: %check_clang_tidy %s misc-use-internal-linkage %t -- -- -I%S/Inputs/use-internal-linkage
+// RUN: %check_clang_tidy %s misc-use-internal-linkage %t -- \
+// RUN:   -config="{CheckOptions: {misc-use-internal-linkage.FixMode: 'UseStatic'}}"  -- -I%S/Inputs/use-internal-linkage
 
 #include "func.h"
 
 void func() {}
 // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function 'func'
+// CHECK-FIXES: static void func() {}
 
 template<class T>
 void func_template() {}
 // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function 'func_template'
+// CHECK-FIXES: static void func_template() {}
 
 void func_cpp_inc();
 // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function 'func_cpp_inc'
+// CHECK-FIXES: static void func_cpp_inc();
 
 #include "func_cpp.inc"
 

clang-tools-extra/test/clang-tidy/checkers/misc/use-internal-linkage-var.cpp

@@ -1,13 +1,17 @@
 // RUN: %check_clang_tidy %s misc-use-internal-linkage %t -- -- -I%S/Inputs/use-internal-linkage
+// RUN: %check_clang_tidy %s misc-use-internal-linkage %t -- \
+// RUN:   -config="{CheckOptions: {misc-use-internal-linkage.FixMode: 'UseStatic'}}"  -- -I%S/Inputs/use-internal-linkage
 
 #include "var.h"
 
 int global;
 // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: variable 'global'
+// CHECK-FIXES: static int global;
 
 template<class T>
 T global_template;
 // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: variable 'global_template'
+// CHECK-FIXES: static T global_template;
 
 int gloabl_header;