Handle va_arg on struct types for the le32 target (PNaCl and Emscripten)

PNaCl and Emscripten can both handle va_arg IR instructions with
struct type.

Also add a test to cover generating a va_arg IR instruction from
va_arg in C on le32 (as already handled by VisitVAArgExpr() in
CGExprScalar.cpp), which was not covered by a test before.

(This fixes https://code.google.com/p/nativeclient/issues/detail?id=2381)

Differential Revision: http://llvm-reviews.chandlerc.com/D2539

llvm-svn: 199830

1 files changed, 5 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/CGExprAgg.cpp b/clang/lib/CodeGen/CGExprAgg.cpp
index 3395bd7d33b..ef56c0b06f2 100644
--- a/clang/lib/CodeGen/CGExprAgg.cpp
+++ b/clang/lib/CodeGen/CGExprAgg.cpp
@@ -935,7 +935,11 @@ void AggExprEmitter::VisitVAArgExpr(VAArgExpr *VE) {
   llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType());
 
   if (!ArgPtr) {
-    CGF.ErrorUnsupported(VE, "aggregate va_arg expression");
+    // If EmitVAArg fails, we fall back to the LLVM instruction.
+    llvm::Value *Val =
+        Builder.CreateVAArg(ArgValue, CGF.ConvertType(VE->getType()));
+    if (!Dest.isIgnored())
+      Builder.CreateStore(Val, Dest.getAddr());
     return;
   }