Fix for PR3350: add special-casing for "references" to va_lists in

builtins.

Also, a minor tweak to va_copy for consistency.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@62574 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 18 insertions, 5 deletions

diff --git a/lib/AST/Builtins.cpp b/lib/AST/Builtins.cpp
index a721c6ea8c..b675c72973 100644
--- a/lib/AST/Builtins.cpp
+++ b/lib/AST/Builtins.cpp
@@ -142,6 +142,23 @@ static QualType DecodeTypeFromStr(const char *&Str, ASTContext &Context,
     Type = Context.getBuiltinVaListType();
     assert(!Type.isNull() && "builtin va list type not initialized!");
     break;
+  case 'A':
+    // This is a "reference" to a va_list; however, what exactly
+    // this means depends on how va_list is defined. There are two
+    // different kinds of va_list: ones passed by value, and ones
+    // passed by reference.  An example of a by-value va_list is
+    // x86, where va_list is a char*. An example of by-ref va_list
+    // is x86-64, where va_list is a __va_list_tag[1]. For x86,
+    // we want this argument to be a char*&; for x86-64, we want
+    // it to be a __va_list_tag*.
+    Type = Context.getBuiltinVaListType();
+    assert(!Type.isNull() && "builtin va list type not initialized!");
+    if (Type->isArrayType()) {
+      Type = Context.getArrayDecayedType(Type);
+    } else {
+      Type = Context.getReferenceType(Type);
+    }
+    break;
   case 'V': {
     char *End;
     
diff --git a/lib/CodeGen/CGBuiltin.cpp b/lib/CodeGen/CGBuiltin.cpp
index 6e140da732..2d840ffd8d 100644
--- a/lib/CodeGen/CGBuiltin.cpp
+++ b/lib/CodeGen/CGBuiltin.cpp
@@ -67,11 +67,7 @@ RValue CodeGenFunction::EmitBuiltinExpr(unsigned BuiltinID, const CallExpr *E) {
   case Builtin::BI__builtin_va_copy: {
     // FIXME: This does not yet handle architectures where va_list is a struct.
     Value *DstPtr = EmitLValue(E->getArg(0)).getAddress();
-    Value *SrcValue = EmitScalarExpr(E->getArg(1));
-    
-    Value *SrcPtr = CreateTempAlloca(SrcValue->getType(), "dst_ptr");
-    
-    Builder.CreateStore(SrcValue, SrcPtr, false);
+    Value *SrcPtr = EmitLValue(E->getArg(1)).getAddress();
 
     const llvm::Type *Type = 
       llvm::PointerType::getUnqual(llvm::Type::Int8Ty);