[CIR] Add decl case for template specialization (#143029)

This change adds the switch case to allow template specialization to
pass through emitTopLevelDecl without issuing an error.

Author: andykaylor

clang/include/clang/CIR/MissingFeatures.h

@@ -217,6 +217,7 @@ struct MissingFeatures {
   static bool peepholeProtection() { return false; }
   static bool instrumentation() { return false; }
   static bool cleanupAfterErrorDiags() { return false; }
+  static bool cxxRecordStaticMembers() { return false; }
 
   // Missing types
   static bool dataMemberType() { return false; }

clang/lib/CIR/CodeGen/CIRGenModule.cpp

@@ -1140,7 +1140,6 @@ void CIRGenModule::emitTopLevelDecl(Decl *decl) {
   case Decl::Typedef:
   case Decl::TypeAlias: // using foo = bar; [C++11]
   case Decl::Record:
-  case Decl::CXXRecord:
     assert(!cir::MissingFeatures::generateDebugInfo());
     break;
 
@@ -1153,6 +1152,12 @@ void CIRGenModule::emitTopLevelDecl(Decl *decl) {
   case Decl::Namespace:
     emitDeclContext(Decl::castToDeclContext(decl));
     break;
+
+  case Decl::ClassTemplateSpecialization:
+  case Decl::CXXRecord:
+    assert(!cir::MissingFeatures::generateDebugInfo());
+    assert(!cir::MissingFeatures::cxxRecordStaticMembers());
+    break;
   }
 }
 

clang/test/CIR/CodeGen/template-specialization.cpp

@@ -0,0 +1,103 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -Wno-unused-value -fclangir -emit-cir %s -o %t.cir
+// RUN: FileCheck --input-file=%t.cir %s -check-prefix=CIR
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -Wno-unused-value -fclangir -emit-llvm %s -o %t-cir.ll
+// RUN: FileCheck --input-file=%t-cir.ll %s -check-prefix=LLVM
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -Wno-unused-value -emit-llvm %s -o %t.ll
+// RUN: FileCheck --input-file=%t.ll %s -check-prefix=OGCG
+
+template<typename T, typename U>
+class Templ {};
+
+template<typename T>
+class Templ<T, int>{};
+
+Templ<int, int> t;
+
+// CIR: !rec_Templ3Cint2C_int3E = !cir.record<class "Templ<int, int>" padded {!u8i}>
+// CIR: cir.global external @t = #cir.zero : !rec_Templ3Cint2C_int3E
+
+// LLVM: %"class.Templ<int, int>" = type { i8 }
+// LLVM: @t = global %"class.Templ<int, int>" zeroinitializer
+
+// OGCG: %class.Templ = type { i8 }
+// OGCG: @t = global %class.Templ zeroinitializer
+
+template<class T>
+class X {
+public:
+  int f() { return 0; }
+};
+
+template<> class X<int> {
+public:
+  int f() { return 1; }
+};
+
+void test_double() {
+  X<double> d;
+  d.f();
+}
+
+// CIR: cir.func{{.*}} @_ZN1XIdE1fEv
+// CIR:   cir.const #cir.int<0>
+//
+// CIR: cir.func{{.*}} @_Z11test_doublev()
+// CIR:   cir.call @_ZN1XIdE1fEv
+
+// LLVM: define{{.*}} i32 @_ZN1XIdE1fEv
+// LLVM:   store i32 0
+//
+// LLVM: define{{.*}} void @_Z11test_doublev()
+// LLVM:   call i32 @_ZN1XIdE1fEv
+
+// OGCG: define{{.*}} void @_Z11test_doublev()
+// OGCG:   call{{.*}} i32 @_ZN1XIdE1fEv
+//
+// OGCG: define{{.*}} i32 @_ZN1XIdE1fEv
+// OGCG:   ret i32 0
+
+void test_int() {
+  X<int> n;
+  n.f();
+}
+
+// CIR: cir.func{{.*}} @_ZN1XIiE1fEv
+// CIR:   cir.const #cir.int<1>
+//
+// CIR: cir.func{{.*}} @_Z8test_intv()
+// CIR:   cir.call @_ZN1XIiE1fEv
+
+// LLVM: define{{.*}} i32 @_ZN1XIiE1fEv
+// LLVM:   store i32 1
+//
+// LLVM: define{{.*}} void @_Z8test_intv()
+// LLVM:   call i32 @_ZN1XIiE1fEv
+
+// OGCG: define{{.*}} void @_Z8test_intv()
+// OGCG:   call{{.*}} i32 @_ZN1XIiE1fEv
+//
+// OGCG: define{{.*}} i32 @_ZN1XIiE1fEv
+// OGCG:   ret i32 1
+
+void test_short() {
+  X<short> s;
+  s.f();
+}
+
+// CIR: cir.func{{.*}} @_ZN1XIsE1fEv
+// CIR:   cir.const #cir.int<0>
+//
+// CIR: cir.func{{.*}} @_Z10test_shortv()
+// CIR:   cir.call @_ZN1XIsE1fEv
+
+// LLVM: define{{.*}} i32 @_ZN1XIsE1fEv
+// LLVM: store i32 0
+//
+// LLVM: define{{.*}} void @_Z10test_shortv()
+// LLVM:   call i32 @_ZN1XIsE1fEv
+
+// OGCG: define{{.*}} void @_Z10test_shortv()
+// OGCG:   call{{.*}} i32 @_ZN1XIsE1fEv
+//
+// OGCG: define{{.*}} i32 @_ZN1XIsE1fEv
+// OGCG:   ret i32 0