[clang] [Clang][Sema] Disable checking invalid template id in primary variable template initializer (PR #139490)

[Yanzuo Liu via cfe-commits]

https://github.com/zwuis created https://github.com/llvm/llvm-project/pull/139490

Workaround for #139067

>From c5a9cda3e5c3aa2b07281e373e9736045a01643b Mon Sep 17 00:00:00 2001
From: Yanzuo Liu <zwuis at outlook.com>
Date: Mon, 12 May 2025 11:08:50 +0800
Subject: [PATCH] Disable checking invalid template id in primary variable
 template initializer

---
 clang/lib/Sema/SemaTemplate.cpp                           | 3 +++
 clang/test/SemaCXX/cxx1y-variable-templates_top_level.cpp | 4 ++--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 7940340064eda..365c61949379d 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -4382,6 +4382,8 @@ Sema::CheckVarTemplateId(VarTemplateDecl *Template, SourceLocation TemplateLoc,
       return Context.isSameTemplateArgument(Arg1, Arg2);
     };
 
+// Workaround for GH139067 / https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120190
+#if 0
     if (VarDecl *Var = Template->getTemplatedDecl();
         ParsingInitForAutoVars.count(Var) &&
         llvm::equal(
@@ -4393,6 +4395,7 @@ Sema::CheckVarTemplateId(VarTemplateDecl *Template, SourceLocation TemplateLoc,
           << diag::ParsingInitFor::VarTemplate << Var << Var->getType();
       return true;
     }
+#endif
 
     SmallVector<VarTemplatePartialSpecializationDecl *, 4> PartialSpecs;
     Template->getPartialSpecializations(PartialSpecs);
diff --git a/clang/test/SemaCXX/cxx1y-variable-templates_top_level.cpp b/clang/test/SemaCXX/cxx1y-variable-templates_top_level.cpp
index 1fe0ce9aabf29..a60d723e477c4 100644
--- a/clang/test/SemaCXX/cxx1y-variable-templates_top_level.cpp
+++ b/clang/test/SemaCXX/cxx1y-variable-templates_top_level.cpp
@@ -495,12 +495,12 @@ static_assert(C<int, 0,1,2,3,4>::VALUEARRAY[0] == 0, "");
 
 namespace appear_in_its_own_init {
 template <class T>
-auto GH51347 = GH51347<T>; // expected-error {{variable template 'GH51347' declared with deduced type 'auto' cannot appear in its own initializer}}
+auto GH51347 = GH51347<T>;
 
 template <class T, class... Ts>
 auto a = [] {
   using U = T;
-  a<U, Ts...>; // expected-error {{variable template 'a' declared with deduced type 'auto' cannot appear in its own initializer}}
+  a<U, Ts...>;
 };
 
 template <int...> int b;