Push record return type classification into CGCXXABI

In the Microsoft C++ ABI, instance methods always return records
indirectly via the second hidden parameter.  This was implemented in
X86_32ABIInfo, but not WinX86_64ABIInfo.

Rather than exposing a handful of boolean methods in the CGCXXABI
interface, we can expose a single method that applies C++ ABI return
value classification rules.

llvm-svn: 208733

1 files changed, 16 insertions, 5 deletions

diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index 8fdcaee31c9..201a7534776 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -52,11 +52,7 @@ public:
     CGCXXABI(CGM), UseARMMethodPtrABI(UseARMMethodPtrABI),
     UseARMGuardVarABI(UseARMGuardVarABI) { }
 
-  bool isReturnTypeIndirect(const CXXRecordDecl *RD) const override {
-    // Structures with either a non-trivial destructor or a non-trivial
-    // copy constructor are always indirect.
-    return !RD->hasTrivialDestructor() || RD->hasNonTrivialCopyConstructor();
-  }
+  bool classifyReturnType(CGFunctionInfo &FI) const override;
 
   RecordArgABI getRecordArgABI(const CXXRecordDecl *RD) const override {
     // Structures with either a non-trivial destructor or a non-trivial
@@ -761,6 +757,21 @@ ItaniumCXXABI::EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
   return Result;
 }
 
+bool ItaniumCXXABI::classifyReturnType(CGFunctionInfo &FI) const {
+  const CXXRecordDecl *RD = FI.getReturnType()->getAsCXXRecordDecl();
+  if (!RD)
+    return false;
+
+  // Return indirectly if we have a non-trivial copy ctor or non-trivial dtor.
+  if (RD->hasNonTrivialDestructor() || RD->hasNonTrivialCopyConstructor()) {
+    FI.getReturnInfo() = ABIArgInfo::getIndirect(0, /*ByVal=*/false);
+    return true;
+  }
+
+  // Otherwise, use the normal C ABI rules.
+  return false;
+}
+
 /// The Itanium ABI requires non-zero initialization only for data
 /// member pointers, for which '0' is a valid offset.
 bool ItaniumCXXABI::isZeroInitializable(const MemberPointerType *MPT) {