Add an alternative implementation of CIE and FDE emission that outputs them

in the same order as the one in CodeGen.

llvm-svn: 130471

1 files changed, 58 insertions, 0 deletions

diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index 7111758a727..18484300486 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -824,9 +824,67 @@ namespace llvm {
   };
 }
 
+// This is an implementation of CIE and FDE emission that is bug by bug
+// compatible with the one in CodeGen. It is useful during the transition
+// to make it easy to compare the outputs, but should probably be removed
+// afterwards.
+void MCDwarfFrameEmitter::EmitDarwin(MCStreamer &streamer) {
+  FrameEmitterImpl Emitter;
+  DenseMap<const MCSymbol*, const MCSymbol*> Personalities;
+  const MCSymbol *aCIE = NULL;
+  const MCDwarfFrameInfo *aFrame = NULL;
+
+  for (unsigned i = 0, n = streamer.getNumFrameInfos(); i < n; ++i) {
+    const MCDwarfFrameInfo &frame = streamer.getFrameInfo(i);
+    if (!frame.Personality)
+      continue;
+    if (Personalities.count(frame.Personality))
+      continue;
+
+    const MCSymbol *cieStart = &Emitter.EmitCIE(streamer, frame.Personality,
+                                                frame.PersonalityEncoding,
+                                                frame.Lsda,
+                                                frame.LsdaEncoding);
+    aCIE = cieStart;
+    aFrame = &frame;
+    Personalities[frame.Personality] = cieStart;
+  }
+
+  if (Personalities.empty()) {
+    const MCDwarfFrameInfo &frame = streamer.getFrameInfo(0);
+    aCIE = &Emitter.EmitCIE(streamer, frame.Personality,
+                            frame.PersonalityEncoding, frame.Lsda,
+                            frame.LsdaEncoding);
+    aFrame = &frame;
+  }
+
+  MCSymbol *fdeEnd = NULL;
+  for (unsigned i = 0, n = streamer.getNumFrameInfos(); i < n; ++i) {
+    const MCDwarfFrameInfo &frame = streamer.getFrameInfo(i);
+    const MCSymbol *cieStart = Personalities[frame.Personality];
+    if (!cieStart)
+      cieStart = aCIE;
+
+    fdeEnd = Emitter.EmitFDE(streamer, *cieStart, frame);
+    if (i != n - 1)
+      streamer.EmitLabel(fdeEnd);
+  }
+
+  const MCContext &context = streamer.getContext();
+  const TargetAsmInfo &asmInfo = context.getTargetAsmInfo();
+  streamer.EmitValueToAlignment(asmInfo.getPointerSize());
+  if (fdeEnd)
+    streamer.EmitLabel(fdeEnd);
+}
+
 void MCDwarfFrameEmitter::Emit(MCStreamer &streamer) {
   const MCContext &context = streamer.getContext();
   const TargetAsmInfo &asmInfo = context.getTargetAsmInfo();
+  if (!asmInfo.isFunctionEHFrameSymbolPrivate()) {
+    EmitDarwin(streamer);
+    return;
+  }
+
   MCSymbol *fdeEnd = NULL;
   DenseMap<CIEKey, const MCSymbol*> CIEStarts;
   FrameEmitterImpl Emitter;