1 files changed, 30 insertions, 1 deletions
diff --git a/clang/lib/CodeGen/CGCXXABI.cpp b/clang/lib/CodeGen/CGCXXABI.cpp
index 033258643dd..e29e525edd2 100644
--- a/clang/lib/CodeGen/CGCXXABI.cpp
+++ b/clang/lib/CodeGen/CGCXXABI.cpp
@@ -30,9 +30,38 @@ void CGCXXABI::ErrorUnsupportedABI(CodeGenFunction &CGF, StringRef S) {
 }
 
 bool CGCXXABI::canCopyArgument(const CXXRecordDecl *RD) const {
+  // If RD has a non-trivial move or copy constructor, we cannot copy the
+  // argument.
+  if (RD->hasNonTrivialCopyConstructor() || RD->hasNonTrivialMoveConstructor())
+    return false;
+
+  // If RD has a non-trivial destructor, we cannot copy the argument.
+  if (RD->hasNonTrivialDestructor())
+    return false;
+
   // We can only copy the argument if there exists at least one trivial,
   // non-deleted copy or move constructor.
-  return RD->canPassInRegisters();
+  // FIXME: This assumes that all lazily declared copy and move constructors are
+  // not deleted.  This assumption might not be true in some corner cases.
+  bool CopyDeleted = false;
+  bool MoveDeleted = false;
+  for (const CXXConstructorDecl *CD : RD->ctors()) {
+    if (CD->isCopyConstructor() || CD->isMoveConstructor()) {
+      assert(CD->isTrivial());
+      // We had at least one undeleted trivial copy or move ctor.  Return
+      // directly.
+      if (!CD->isDeleted())
+        return true;
+      if (CD->isCopyConstructor())
+        CopyDeleted = true;
+      else
+        MoveDeleted = true;
+    }
+  }
+
+  // If all trivial copy and move constructors are deleted, we cannot copy the
+  // argument.
+  return !(CopyDeleted && MoveDeleted);
 }
 
 llvm::Constant *CGCXXABI::GetBogusMemberPointer(QualType T) {