r237630 - Revert changes to DefaultABIInfo accidentally introduced in r208733

[Reid Kleckner]

Author: rnk
Date: Mon May 18 17:46:30 2015
New Revision: 237630

URL: http://llvm.org/viewvc/llvm-project?rev=237630&view=rev
Log:
Revert changes to DefaultABIInfo accidentally introduced in r208733

Also add trivial handling of transparent unions.

PPC32, MSP430, and XCore apparently all rely on DefaultABIInfo. This
should worry you, because DefaultABIInfo is not implementing the rules
of any particular ABI.

Fixes PR23097, patch by Andy Gibbs.

Added:
    cfe/trunk/test/CodeGenCXX/powerpc-byval.cpp
Modified:
    cfe/trunk/lib/CodeGen/TargetInfo.cpp

Modified: cfe/trunk/lib/CodeGen/TargetInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/TargetInfo.cpp?rev=237630&r1=237629&r2=237630&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/TargetInfo.cpp (original)
+++ cfe/trunk/lib/CodeGen/TargetInfo.cpp Mon May 18 17:46:30 2015
@@ -406,8 +406,16 @@ llvm::Value *DefaultABIInfo::EmitVAArg(l
 }
 
 ABIArgInfo DefaultABIInfo::classifyArgumentType(QualType Ty) const {
-  if (isAggregateTypeForABI(Ty))
+  Ty = useFirstFieldIfTransparentUnion(Ty);
+
+  if (isAggregateTypeForABI(Ty)) {
+    // Records with non-trivial destructors/copy-constructors should not be
+    // passed by value.
+    if (CGCXXABI::RecordArgABI RAA = getRecordArgABI(Ty, getCXXABI()))
+      return ABIArgInfo::getIndirect(0, RAA == CGCXXABI::RAA_DirectInMemory);
+
     return ABIArgInfo::getIndirect(0);
+  }
 
   // Treat an enum type as its underlying type.
   if (const EnumType *EnumTy = Ty->getAs<EnumType>())

Added: cfe/trunk/test/CodeGenCXX/powerpc-byval.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/powerpc-byval.cpp?rev=237630&view=auto
==============================================================================
--- cfe/trunk/test/CodeGenCXX/powerpc-byval.cpp (added)
+++ cfe/trunk/test/CodeGenCXX/powerpc-byval.cpp Mon May 18 17:46:30 2015
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -emit-llvm %s -o - -triple=powerpc-unknown-linux | FileCheck %s
+
+struct S {
+  S();
+  ~S();
+};
+
+void byval(S one, S two) {
+  one = two;
+}
+
+// CHECK: define void @_Z5byval1SS_(%struct.S* %one, %struct.S* %two)