[MC] Suppress .Lcfi labels when emitting textual assembly
Summary:
This suppresses the generation of .Lcfi labels in our textual assembler.
It was annoying that this generated cascading .Lcfi labels:
llc foo.ll -o - | llvm-mc | llvm-mc
After three trips through MCAsmStreamer, we'd have three labels in the
output when none are necessary. We should only bother creating the
labels and frame data when making a real object file.
This supercedes D38605, which moved the entire .seh_ implementation into
MCObjectStreamer.
This has the advantage that we do more checking when emitting textual
assembly, as a minor efficiency cost. Outputting textual assembly is not
performance critical, so this shouldn't matter.
Reviewers: majnemer, MatzeB
Subscribers: qcolombet, nemanjai, javed.absar, eraman, hiraditya, JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D38638
llvm-svn: 315259
diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index 7521a75..866bad9 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -355,13 +355,13 @@
void MCStreamer::EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) {
// Put a dummy non-null value in Frame.End to mark that this frame has been
// closed.
- Frame.End = (MCSymbol *) 1;
+ Frame.End = (MCSymbol *)1;
}
MCSymbol *MCStreamer::EmitCFILabel() {
- MCSymbol *Label = getContext().createTempSymbol("cfi", true);
- EmitLabel(Label);
- return Label;
+ // Return a dummy non-null value so that label fields appear filled in when
+ // generating textual assembly.
+ return (MCSymbol *)1;
}
MCSymbol *MCStreamer::EmitCFICommon() {
@@ -735,6 +735,8 @@
void MCStreamer::Finish() {
if (!DwarfFrameInfos.empty() && !DwarfFrameInfos.back().End)
report_fatal_error("Unfinished frame!");
+ if (!WinFrameInfos.empty() && !WinFrameInfos.back()->End)
+ report_fatal_error("Unfinished frame!");
MCTargetStreamer *TS = getTargetStreamer();
if (TS)