Start adding basic support for emitting the call frame instructions.

llvm-svn: 122590

2 files changed, 13 insertions, 2 deletions

diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index cd5141083e3..6e59a58b04d 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -460,9 +460,11 @@ static void EmitFrameMoves(MCStreamer &streamer,
     if (BaseLabel && Label) {
       MCSymbol *ThisSym = Label;
       if (ThisSym != BaseLabel) {
+        // FIXME: We should relax this instead of using a DW_CFA_advance_loc4
+        // for every address change!
         streamer.EmitIntValue(dwarf::DW_CFA_advance_loc4, 1);
         const MCExpr *Length = MakeStartMinusEndExpr(streamer, *BaseLabel,
-                                                     *ThisSym, 4);
+                                                     *ThisSym, 0);
         streamer.EmitValue(Length, 4);
         BaseLabel = ThisSym;
       }
@@ -672,6 +674,8 @@ static MCSymbol *EmitFDE(MCStreamer &streamer,
   streamer.EmitLabel(augmentationEnd);
   // Call Frame Instructions
 
+  EmitFrameMoves(streamer, frame.Moves, frame.Begin, true);
+
   // Padding
   streamer.EmitValueToAlignment(4);
 
diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index 922a40ce3e7..048e8866bde 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -157,7 +157,7 @@ bool MCStreamer::EmitCFIStartProc() {
     report_fatal_error("Starting a frame before finishing the previous one!");
     return true;
   }
-  MCDwarfFrameInfo Frame = {0, 0, 0, 0, 0, 0};
+  MCDwarfFrameInfo Frame;
   Frame.Begin = getContext().CreateTempSymbol();
   EmitLabel(Frame.Begin);
   FrameInfos.push_back(Frame);
@@ -174,6 +174,13 @@ bool MCStreamer::EmitCFIEndProc() {
 
 bool MCStreamer::EmitCFIDefCfaOffset(int64_t Offset) {
   EnsureValidFrame();
+  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
+  MCSymbol *Label = getContext().CreateTempSymbol();
+  EmitLabel(Label);
+  MachineLocation Dest(MachineLocation::VirtualFP);
+  MachineLocation Source(MachineLocation::VirtualFP, -Offset);
+  MachineMove Move(Label, Dest, Source);
+  CurFrame->Moves.push_back(Move);
   return false;
 }