[clang-tidy] support unscoped enumerations in readability-static-acce…

…ssed-through-instance

fixed [60810](#60810)
unscoped enumerations in class can also be checked by `readability-static-accessed-through-instance`
add matcher for `enumConstantDecl` to match format
```
struct {
    enum { E1 };
};
```
The filter of member expression and the fix hint should be same as other condition.

Reviewed By: PiotrZSL

Differential Revision: https://reviews.llvm.org/D147315

clang-tools-extra/clang-tidy/readability/StaticAccessedThroughInstanceCheck.cpp

@@ -39,7 +39,8 @@ void StaticAccessedThroughInstanceCheck::storeOptions(
 void StaticAccessedThroughInstanceCheck::registerMatchers(MatchFinder *Finder) {
   Finder->addMatcher(
       memberExpr(hasDeclaration(anyOf(cxxMethodDecl(isStaticStorageClass()),
-                                      varDecl(hasStaticStorageDuration()))))
+                                      varDecl(hasStaticStorageDuration()),
+                                      enumConstantDecl())))
           .bind("memberExpression"),
       this);
 }
@@ -64,15 +65,15 @@ void StaticAccessedThroughInstanceCheck::check(
           : BaseExpr->getType().getUnqualifiedType();
 
   const ASTContext *AstContext = Result.Context;
-  PrintingPolicy PrintingPolicyWithSupressedTag(AstContext->getLangOpts());
-  PrintingPolicyWithSupressedTag.SuppressTagKeyword = true;
-  PrintingPolicyWithSupressedTag.SuppressUnwrittenScope = true;
+  PrintingPolicy PrintingPolicyWithSuppressedTag(AstContext->getLangOpts());
+  PrintingPolicyWithSuppressedTag.SuppressTagKeyword = true;
+  PrintingPolicyWithSuppressedTag.SuppressUnwrittenScope = true;
 
-  PrintingPolicyWithSupressedTag.PrintCanonicalTypes =
+  PrintingPolicyWithSuppressedTag.PrintCanonicalTypes =
       !BaseExpr->getType()->isTypedefNameType();
 
   std::string BaseTypeName =
-      BaseType.getAsString(PrintingPolicyWithSupressedTag);
+      BaseType.getAsString(PrintingPolicyWithSuppressedTag);
 
   // Do not warn for CUDA built-in variables.
   if (StringRef(BaseTypeName).startswith("__cuda_builtin_"))

clang-tools-extra/docs/ReleaseNotes.rst

@@ -254,6 +254,10 @@ Changes in existing checks
   <clang-tidy/checks/readability/misleading-indentation>` check when warning would
   be unnecessarily emitted for template dependent ``if constexpr``.
 
+- Improved :doc:`readability-static-accessed-through-instance
+  <clang-tidy/checks/readability/static-accessed-through-instance>` check to 
+  support unscoped enumerations through instances.
+
 - Fixed a false positive in :doc:`cppcoreguidelines-slicing
   <clang-tidy/checks/cppcoreguidelines/slicing>` check when warning would be
   emitted in constructor for virtual base class initialization.

clang-tools-extra/docs/clang-tidy/checks/readability/static-accessed-through-instance.rst

@@ -15,11 +15,15 @@ The following code:
   struct C {
     static void foo();
     static int x;
+    enum { E1 };
+    enum E { E2 };
   };
 
   C *c1 = new C();
   c1->foo();
   c1->x;
+  c1->E1;
+  c1->E2;
 
 is changed to:
 
@@ -28,4 +32,6 @@ is changed to:
   C *c1 = new C();
   C::foo();
   C::x;
+  C::E1;
+  C::E2;
 

clang-tools-extra/test/clang-tidy/checkers/readability/static-accessed-through-instance.cpp

@@ -1,10 +1,21 @@
 // RUN: %check_clang_tidy %s readability-static-accessed-through-instance %t -- -- -isystem %S/Inputs/static-accessed-through-instance
 #include <__clang_cuda_builtin_vars.h>
 
+enum OutEnum {
+  E0,
+};
+
 struct C {
   static void foo();
   static int x;
   int nsx;
+  enum {
+    Anonymous,
+  };
+  enum E {
+    E1,
+  };
+  using enum OutEnum;
   void mf() {
     (void)&x;    // OK, x is accessed inside the struct.
     (void)&C::x; // OK, x is accessed using a qualified-id.
@@ -144,6 +155,16 @@ void static_through_instance() {
   c1->x; // 2
   // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: static member
   // CHECK-FIXES: {{^}}  C::x; // 2{{$}}
+  c1->Anonymous; // 3
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: static member
+  // CHECK-FIXES: {{^}}  C::Anonymous; // 3{{$}}
+  c1->E1; // 4
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: static member
+  // CHECK-FIXES: {{^}}  C::E1; // 4{{$}}
+  c1->E0; // 5
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: static member
+  // CHECK-FIXES: {{^}}  C::E0; // 5{{$}}
+
   c1->nsx; // OK, nsx is a non-static member.
 
   const C *c2 = new C();