[PATCH] D144931: DebugInfo: Disable ctor homing for types with only deleted (non copy/move) ctors

[David Blaikie via Phabricator via cfe-commits]

dblaikie created this revision.
dblaikie added a reviewer: akhuang.
Herald added a project: All.
dblaikie requested review of this revision.
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Such a type is never going to have a ctor home, and may be used for type
punning or other ways of creating objects.

May be a more generally acceptable solution in some cases compared to
attributing with [[clang::standalone_debug]].


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D144931

Files:
  clang/lib/CodeGen/CGDebugInfo.cpp
  clang/test/CodeGenCXX/debug-info-limited-ctor.cpp


Index: clang/test/CodeGenCXX/debug-info-limited-ctor.cpp
===================================================================
--- clang/test/CodeGenCXX/debug-info-limited-ctor.cpp
+++ clang/test/CodeGenCXX/debug-info-limited-ctor.cpp
@@ -68,6 +68,21 @@
 };
 void f(K k) {}
 
+// CHECK-DAG: !DICompositeType({{.*}}name: 
"DeletedCtors",{{.*}}DIFlagTypePassBy
+struct NonTrivial {
+  NonTrivial();
+};
+struct DeletedCtors {
+  DeletedCtors() = delete;
+  DeletedCtors(const DeletedCtors &) = default;
+  void f1();
+  NonTrivial t;
+};
+
+const NonTrivial &f(const DeletedCtors &D) {
+  return D.t;
+}
+
 // Test that we don't use constructor homing on lambdas.
 // CHECK-DAG: ![[L:.*]] ={{.*}}!DISubprogram({{.*}}name: "L"
 // CHECK-DAG: !DICompositeType({{.*}}scope: ![[L]], {{.*}}DIFlagTypePassByValue
@@ -89,3 +104,4 @@
 }
 
 // ITANIUM-DAG: !DICompositeType({{.*}}name: "VTableAndCtor", {{.*}}flags: 
DIFlagFwdDecl
+
Index: clang/lib/CodeGen/CGDebugInfo.cpp
===================================================================
--- clang/lib/CodeGen/CGDebugInfo.cpp
+++ clang/lib/CodeGen/CGDebugInfo.cpp
@@ -2489,9 +2489,18 @@
   if (isClassOrMethodDLLImport(RD))
     return false;
 
-  return !RD->isLambda() && !RD->isAggregate() &&
-         !RD->hasTrivialDefaultConstructor() &&
-         !RD->hasConstexprNonCopyMoveConstructor();
+  if (RD->isLambda() || RD->isAggregate() ||
+      RD->hasTrivialDefaultConstructor() ||
+      RD->hasConstexprNonCopyMoveConstructor())
+    return false;
+
+  for (const CXXConstructorDecl *Ctor : RD->ctors()) {
+    if (Ctor->isCopyOrMoveConstructor())
+      continue;
+    if (!Ctor->isDeleted())
+      return true;
+  }
+  return false;
 }
 
 static bool shouldOmitDefinition(codegenoptions::DebugInfoKind DebugKind,



Index: clang/test/CodeGenCXX/debug-info-limited-ctor.cpp
===================================================================
--- clang/test/CodeGenCXX/debug-info-limited-ctor.cpp
+++ clang/test/CodeGenCXX/debug-info-limited-ctor.cpp
@@ -68,6 +68,21 @@
 };
 void f(K k) {}
 
+// CHECK-DAG: !DICompositeType({{.*}}name: "DeletedCtors",{{.*}}DIFlagTypePassBy
+struct NonTrivial {
+  NonTrivial();
+};
+struct DeletedCtors {
+  DeletedCtors() = delete;
+  DeletedCtors(const DeletedCtors &) = default;
+  void f1();
+  NonTrivial t;
+};
+
+const NonTrivial &f(const DeletedCtors &D) {
+  return D.t;
+}
+
 // Test that we don't use constructor homing on lambdas.
 // CHECK-DAG: ![[L:.*]] ={{.*}}!DISubprogram({{.*}}name: "L"
 // CHECK-DAG: !DICompositeType({{.*}}scope: ![[L]], {{.*}}DIFlagTypePassByValue
@@ -89,3 +104,4 @@
 }
 
 // ITANIUM-DAG: !DICompositeType({{.*}}name: "VTableAndCtor", {{.*}}flags: DIFlagFwdDecl
+
Index: clang/lib/CodeGen/CGDebugInfo.cpp
===================================================================
--- clang/lib/CodeGen/CGDebugInfo.cpp
+++ clang/lib/CodeGen/CGDebugInfo.cpp
@@ -2489,9 +2489,18 @@
   if (isClassOrMethodDLLImport(RD))
     return false;
 
-  return !RD->isLambda() && !RD->isAggregate() &&
-         !RD->hasTrivialDefaultConstructor() &&
-         !RD->hasConstexprNonCopyMoveConstructor();
+  if (RD->isLambda() || RD->isAggregate() ||
+      RD->hasTrivialDefaultConstructor() ||
+      RD->hasConstexprNonCopyMoveConstructor())
+    return false;
+
+  for (const CXXConstructorDecl *Ctor : RD->ctors()) {
+    if (Ctor->isCopyOrMoveConstructor())
+      continue;
+    if (!Ctor->isDeleted())
+      return true;
+  }
+  return false;
 }
 
 static bool shouldOmitDefinition(codegenoptions::DebugInfoKind DebugKind,

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