[DebugInfo] Change to constructor homing debug info mode: skip literal types

Summary:
In constructor type homing mode sometimes complete debug info for constexpr
types was missing, because there was not a constructor emitted. This change
makes constructor type homing ignore constexpr types.

Reviewers: rnk, dblaikie

Subscribers: aprantl, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D77432

Author: amykhuang

clang/lib/CodeGen/CGDebugInfo.cpp

@@ -2261,12 +2261,11 @@ static bool shouldOmitDefinition(codegenoptions::DebugInfoKind DebugKind,
   // constructor is emitted. Skip this optimization if the class or any of
   // its methods are marked dllimport.
   if (DebugKind == codegenoptions::DebugInfoConstructor &&
-      !CXXDecl->isLambda() && !isClassOrMethodDLLImport(CXXDecl)) {
-    for (const auto *Ctor : CXXDecl->ctors()) {
+      !CXXDecl->isLambda() && !CXXDecl->hasConstexprNonCopyMoveConstructor() &&
+      !isClassOrMethodDLLImport(CXXDecl))
+    for (const auto *Ctor : CXXDecl->ctors())
       if (Ctor->isUserProvided())
         return true;
-    }
-  }
 
   TemplateSpecializationKind Spec = TSK_Undeclared;
   if (const auto *SD = dyn_cast<ClassTemplateSpecializationDecl>(RD))

clang/test/CodeGenCXX/debug-info-limited-ctor.cpp

@@ -1,30 +1,26 @@
 // RUN: %clang -cc1 -debug-info-kind=constructor -emit-llvm %s -o - | FileCheck %s
 
-// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "A"
-// CHECK-NOT:              DIFlagFwdDecl
-// CHECK-SAME:             ){{$}}
-struct A {};
-void TestA() { A a; }
+// CHECK-DAG: !DICompositeType(tag: DW_TAG_structure_type, name: "A"{{.*}}DIFlagTypePassByValue
+struct A {
+} TestA;
 
-// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "B"
-// CHECK-SAME:             flags: DIFlagFwdDecl
+// CHECK-DAG: !DICompositeType(tag: DW_TAG_structure_type, name: "B"{{.*}}flags: DIFlagFwdDecl
 struct B {
   B();
-};
-void TestB() { B b; }
+} TestB;
 
-// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "C"
-// CHECK-NOT:              flags: DIFlagFwdDecl
-// CHECK-SAME:             ){{$}}
+// CHECK-DAG: !DICompositeType(tag: DW_TAG_structure_type, name: "C"{{.*}}DIFlagTypePassByValue
 struct C {
   C() {}
-};
-void TestC() { C c; }
+} TestC;
 
-// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "D"
-// CHECK-NOT:              flags: DIFlagFwdDecl
-// CHECK-SAME:             ){{$}}
+// CHECK-DAG: !DICompositeType(tag: DW_TAG_structure_type, name: "D"{{.*}}DIFlagTypePassByValue
 struct D {
   D();
 };
 D::D() {}
+
+// CHECK-DAG: !DICompositeType(tag: DW_TAG_structure_type, name: "E"{{.*}}DIFlagTypePassByValue
+struct E {
+  constexpr E(){};
+} TestE;