[clang] [DebugInfo] Ignore delegating constructors in constructor homing. (PR #218807)

[David Blaikie via cfe-commits]

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@@ -27,6 +27,39 @@ struct E {
   constexpr E(){};
 } TestE;
 
+// Defined delegating constructor where delegated constructor is not defined
+// should not emit full debug info.
+// CHECK-DAG: !DICompositeType(tag: DW_TAG_structure_type, name: "Delegating"{{.*}}flags: DIFlagFwdDecl
+struct Delegating {
+  Delegating() : Delegating(42) {}
+  Delegating(int);
+} TestDelegating;
+
+// Defined delegating constructor where delegated constructor is defined should
+// emit full debug info.
+// CHECK-DAG: !DICompositeType(tag: DW_TAG_structure_type, name: "DelegatingToDefined"{{.*}}DIFlagTypePassByValue
+struct DelegatingToDefined {
+  DelegatingToDefined() : DelegatingToDefined(42) {}
+  DelegatingToDefined(int) {}
+} TestDelegatingToDefined;
+
+// Defined out-of-line delegating constructor where delegated constructor is
+// defined should emit full debug info.
+// CHECK-DAG: !DICompositeType(tag: DW_TAG_structure_type, name: "DelegatingOutOfLine"{{.*}}DIFlagTypePassByValue
+struct DelegatingOutOfLine {
+  DelegatingOutOfLine();
+  DelegatingOutOfLine(int) {}
+};
+DelegatingOutOfLine d;
+DelegatingOutOfLine::DelegatingOutOfLine() : DelegatingOutOfLine(42) {}
----------------
dwblaikie wrote:

What happens if the delegating ctor is out of line but not defined in this translation unit? Does it then correctly home to the translation unit where the delegating ctor's definition (calling the underlying, inline ctor) is?

https://github.com/llvm/llvm-project/pull/218807