clang-tidy/readability-identifier-naming: crash on DependentTemplateSpecializationType

[mgehre]

Summary

Previously, the added test cases crashed because Ref.getTypePtr()->getAsTagDecl()
is nullptr.

[mgehre]

Add a second test case and fix

[alexfh]

LG. Thanks!

Is it related to https://llvm.org/bugs/show_bug.cgi?id=28481 ?

[mgehre]

I didn't see that bug before, but with my patch, I cannot reproduce the reported crash.
So I guess that fixed it.

clang-tools-extra/trunk/clang-tidy/readability/IdentifierNamingCheck.cpp

if (const auto *Loc = Result.Nodes.getNodeAs<TypeLoc>("typeLoc")) {
     }
 
     if (const auto &Ref = Loc->getAs<TemplateSpecializationTypeLoc>()) {
       const auto *Decl =
           Ref.getTypePtr()->getTemplateName().getAsTemplateDecl();
 
       SourceRange Range(Ref.getTemplateNameLoc(), Ref.getTemplateNameLoc());
       if (const auto *ClassDecl = dyn_cast<TemplateDecl>(Decl)) {
-        addUsage(NamingCheckFailures, ClassDecl->getTemplatedDecl(), Range);
+        if (const auto *TemplDecl = ClassDecl->getTemplatedDecl())
+          addUsage(NamingCheckFailures, TemplDecl, Range);
         return;
       }
     }
 
     if (const auto &Ref =
             Loc->getAs<DependentTemplateSpecializationTypeLoc>()) {
-      addUsage(NamingCheckFailures, Ref.getTypePtr()->getAsTagDecl(),
-               Loc->getSourceRange());
+      if (const auto *Decl = Ref.getTypePtr()->getAsTagDecl())
+        addUsage(NamingCheckFailures, Decl, Loc->getSourceRange());
       return;
     }
   }
 
   if (const auto *Loc =
           Result.Nodes.getNodeAs<NestedNameSpecifierLoc>("nestedNameLoc")) {
     if (NestedNameSpecifier *Spec = Loc->getNestedNameSpecifier()) {
       if (NamespaceDecl *Decl = Spec->getAsNamespace()) {

clang-tools-extra/trunk/test/clang-tidy/readability-identifier-naming.cpp

 #define MY_TEST_Macro(X) X()
 // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: invalid case style for macro definition 'MY_TEST_Macro'
 // CHECK-FIXES: {{^}}#define MY_TEST_MACRO(X) X()
 
 void MY_TEST_Macro(function) {}
 // CHECK-FIXES: {{^}}void MY_TEST_MACRO(function) {}
 }
 }
+
+template <typename t_t> struct a {
+  typename t_t::template b<> c;
+};
+
+template <template <typename> class A> struct b { A<int> c; };