Implement MCAsmStreamer::EmitDwarfAdvanceFrameAddr.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130585 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCStreamer.cpp b/lib/MC/MCStreamer.cpp
index b5cddcd..55ccf56 100644
--- a/lib/MC/MCStreamer.cpp
+++ b/lib/MC/MCStreamer.cpp
@@ -28,6 +28,29 @@
 MCStreamer::~MCStreamer() {
 }
 
+const MCExpr *MCStreamer::BuildSymbolDiff(MCContext &Context,
+                                          const MCSymbol *A,
+                                          const MCSymbol *B) {
+  MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None;
+  const MCExpr *ARef =
+    MCSymbolRefExpr::Create(A, Variant, Context);
+  const MCExpr *BRef =
+    MCSymbolRefExpr::Create(B, Variant, Context);
+  const MCExpr *AddrDelta =
+    MCBinaryExpr::Create(MCBinaryExpr::Sub, ARef, BRef, Context);
+  return AddrDelta;
+}
+
+const MCExpr *MCStreamer::ForceExpAbs(MCStreamer *Streamer,
+                                      MCContext &Context, const MCExpr* Expr) {
+ if (Context.getAsmInfo().hasAggressiveSymbolFolding())
+   return Expr;
+
+ MCSymbol *ABS = Context.CreateTempSymbol();
+ Streamer->EmitAssignment(ABS, Expr);
+ return MCSymbolRefExpr::Create(ABS, Context);
+}
+
 raw_ostream &MCStreamer::GetCommentOS() {
   // By default, discard comments.
   return nulls();