[clang] d8a1a55 - DebugInfo: Disable ctor homing for types with only deleted (non copy/move) ctors

[David Blaikie via cfe-commits]

Author: David Blaikie
Date: 2023-02-28T01:25:22Z
New Revision: d8a1a559f3009a31c517f864156db91d2ae3012c

URL: https://github.com/llvm/llvm-project/commit/d8a1a559f3009a31c517f864156db91d2ae3012c
DIFF: https://github.com/llvm/llvm-project/commit/d8a1a559f3009a31c517f864156db91d2ae3012c.diff

LOG: DebugInfo: Disable ctor homing for types with only deleted (non copy/move) ctors

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]].

Differential Revision: https://reviews.llvm.org/D144931

Added: 
    

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

Removed: 
    


################################################################################
diff  --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 4dab595ada76b..126b239042ee1 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -2489,9 +2489,18 @@ static bool canUseCtorHoming(const CXXRecordDecl *RD) {
   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,

diff  --git a/clang/test/CodeGenCXX/debug-info-limited-ctor.cpp b/clang/test/CodeGenCXX/debug-info-limited-ctor.cpp
index ac53cace075cd..18adfdeed0480 100644
--- a/clang/test/CodeGenCXX/debug-info-limited-ctor.cpp
+++ b/clang/test/CodeGenCXX/debug-info-limited-ctor.cpp
@@ -68,6 +68,21 @@ class K {
 };
 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 @@ VTableAndCtor::VTableAndCtor() {
 }
 
 // ITANIUM-DAG: !DICompositeType({{.*}}name: "VTableAndCtor", {{.*}}flags: DIFlagFwdDecl
+