[CIR] Add handling for static data members

This adds some trivial handling to force emitting of child decls inside
C++ records.

Author: andykaylor

clang/include/clang/CIR/MissingFeatures.h

@@ -239,7 +239,6 @@ struct MissingFeatures {
   static bool ctorConstLvalueToRvalueConversion() { return false; }
   static bool ctorMemcpyizer() { return false; }
   static bool cudaSupport() { return false; }
-  static bool cxxRecordStaticMembers() { return false; }
   static bool dataLayoutTypeIsSized() { return false; }
   static bool dataLayoutTypeAllocSize() { return false; }
   static bool dataLayoutTypeStoreSize() { return false; }

clang/lib/CIR/CodeGen/CIRGenModule.cpp

@@ -1556,10 +1556,14 @@ void CIRGenModule::emitTopLevelDecl(Decl *decl) {
     break;
 
   case Decl::ClassTemplateSpecialization:
-  case Decl::CXXRecord:
+  case Decl::CXXRecord: {
+    CXXRecordDecl *crd = cast<CXXRecordDecl>(decl);
     assert(!cir::MissingFeatures::generateDebugInfo());
-    assert(!cir::MissingFeatures::cxxRecordStaticMembers());
+    for (auto *childDecl : crd->decls())
+      if (isa<VarDecl>(childDecl) || isa<CXXRecordDecl>(childDecl))
+        emitTopLevelDecl(childDecl);
     break;
+  }
 
   case Decl::FileScopeAsm:
     // File-scope asm is ignored during device-side CUDA compilation.

clang/test/CIR/CodeGen/static-members.cpp

@@ -0,0 +1,53 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-cir %s -o %t.cir
+// RUN: FileCheck %s -check-prefix=CIR --input-file=%t.cir
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-llvm %s -o %t-cir.ll
+// RUN: FileCheck %s -check-prefix=LLVM --input-file=%t-cir.ll
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm %s -o %t.ll
+// RUN: FileCheck %s -check-prefix=OGCG --input-file=%t.ll
+
+struct HasDtor {
+  ~HasDtor();
+};
+struct S {
+  static inline HasDtor hd;
+};
+
+// CIR: cir.global linkonce_odr comdat @_ZN1S2hdE = #cir.zero : !rec_HasDtor
+
+// CIR: cir.func internal private @__cxx_global_var_init() {
+// CIR:   %[[HD:.*]] = cir.get_global @_ZN1S2hdE : !cir.ptr<!rec_HasDtor>
+// CIR:   %[[DTOR:.*]] = cir.get_global @_ZN7HasDtorD1Ev : !cir.ptr<!cir.func<(!cir.ptr<!rec_HasDtor>)>>
+// CIR:   %[[DTOR_CAST:.*]] = cir.cast bitcast %[[DTOR]] : !cir.ptr<!cir.func<(!cir.ptr<!rec_HasDtor>)>> -> !cir.ptr<!cir.func<(!cir.ptr<!void>)>>
+// CIR:   %[[HD_CAST:.*]] = cir.cast bitcast %[[HD]] : !cir.ptr<!rec_HasDtor> -> !cir.ptr<!void>
+// CIR:   %[[HANDLE:.*]] = cir.get_global @__dso_handle : !cir.ptr<i8>
+// CIR:   cir.call @__cxa_atexit(%[[DTOR_CAST]], %[[HD_CAST]], %[[HANDLE]])
+
+// CIR: cir.func private @_GLOBAL__sub_I_static_members.cpp()
+// CIR:   cir.call @__cxx_global_var_init()
+
+// LLVM: @_ZN1S2hdE = linkonce_odr global %struct.HasDtor zeroinitializer, comdat
+// LLVM: @llvm.global_ctors = appending global [1 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 65535, ptr @_GLOBAL__sub_I_static_members.cpp, ptr null }]
+// LLVM: define internal void @__cxx_global_var_init()
+// LLVM:   call void @__cxa_atexit(ptr @_ZN7HasDtorD1Ev, ptr @_ZN1S2hdE, ptr @__dso_handle)
+// LLVM: define void @_GLOBAL__sub_I_static_members.cpp()
+// LLVM:   call void @__cxx_global_var_init()
+
+// FIXME(cir): OGCG has a guard variable for this case that we don't generate in CIR.
+//             This is needed because the variable linkonce_odr linkage.
+
+// OGCG: @_ZN1S2hdE = linkonce_odr global %struct.HasDtor zeroinitializer, comdat
+// OGCG: @_ZGVN1S2hdE = linkonce_odr global i64 0, comdat($_ZN1S2hdE)
+// OGCG: @llvm.global_ctors = appending global [1 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 65535, ptr @__cxx_global_var_init, ptr @_ZN1S2hdE }]
+// OGCG: define internal void @__cxx_global_var_init() {{.*}} section ".text.startup" comdat($_ZN1S2hdE) {
+// OGCG:   %[[GUARD:.*]] = load atomic i8, ptr @_ZGVN1S2hdE acquire
+// OGCG:   %[[UNINIT:.*]] = icmp eq i8 %[[GUARD]], 0
+// OGCG:   br i1 %[[UNINIT]], label %[[INIT_CHECK:.*]], label %[[INIT_END:.*]]
+// OGCG: [[INIT_CHECK:.*]]:
+// OGCG:   %[[GUARD_ACQUIRE:.*]] = call i32 @__cxa_guard_acquire(ptr @_ZGVN1S2hdE)
+// OGCG:   %[[TOBOOL:.*]] = icmp ne i32 %[[GUARD_ACQUIRE]], 0
+// OGCG:   br i1 %[[TOBOOL]], label %[[INIT:.*]], label %[[INIT_END]]
+// OGCG: [[INIT:.*]]:
+// OGCG:   %[[ATEXIT:.*]] = call i32 @__cxa_atexit(ptr @_ZN7HasDtorD1Ev, ptr @_ZN1S2hdE, ptr @__dso_handle)
+// OGCG:   call void @__cxa_guard_release(ptr @_ZGVN1S2hdE)
+// OGCG:   br label %[[INIT_END]]
+// OGCG: [[INIT_END]]: