[llvm-commits] [llvm] r133676 - /llvm/trunk/lib/MC/MCDwarf.cpp
Bill Wendling
isanbard at gmail.com
Wed Jun 22 18:06:23 PDT 2011
Author: void
Date: Wed Jun 22 20:06:23 2011
New Revision: 133676
URL: http://llvm.org/viewvc/llvm-project?rev=133676&view=rev
Log:
Some skeleton code to emit the compact unwind. If the information is unable to
be emitted in a compact way, we then default to emitting a CIE and FDE.
Modified:
llvm/trunk/lib/MC/MCDwarf.cpp
Modified: llvm/trunk/lib/MC/MCDwarf.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCDwarf.cpp?rev=133676&r1=133675&r2=133676&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCDwarf.cpp (original)
+++ llvm/trunk/lib/MC/MCDwarf.cpp Wed Jun 22 20:06:23 2011
@@ -507,6 +507,12 @@
SectionStart(sectionStart) {
}
+ /// EmitCompactUnwind - Emit the unwind information in a compact way. If
+ /// we're successful, return 'true'. Otherwise, return 'false' and it will
+ /// emit the normal CIE and FDE.
+ bool EmitCompactUnwind(MCStreamer &streamer,
+ const MCDwarfFrameInfo &frame);
+
const MCSymbol &EmitCIE(MCStreamer &streamer,
const MCSymbol *personality,
unsigned personalityEncoding,
@@ -620,6 +626,55 @@
}
}
+/// EmitCompactUnwind - Emit the unwind information in a compact way. If we're
+/// successful, return 'true'. Otherwise, return 'false' and it will emit the
+/// normal CIE and FDE.
+bool FrameEmitterImpl::EmitCompactUnwind(MCStreamer &Streamer,
+ const MCDwarfFrameInfo &Frame) {
+#if 1
+ return false;
+#else
+ MCContext &Context = Streamer.getContext();
+ const TargetAsmInfo &TAI = Context.getTargetAsmInfo();
+ Streamer.SwitchSection(TAI.getCompactUnwindSection());
+
+ unsigned FDEEncoding = TAI.getFDEEncoding(UsingCFI);
+ unsigned Size = getSizeForEncoding(Streamer, FDEEncoding);
+
+ // range-start range-length compact-unwind-enc personality-func lsda
+ // _foo LfooEnd-_foo 0x00000023 0 0
+ // _bar LbarEnd-_bar 0x00000025 __gxx_personality except_tab1
+ //
+ // .section __LD,__compact_unwind,regular,debug
+ //
+ // # compact unwind for _foo
+ // .quad _foo
+ // .set L1,LfooEnd-_foo
+ // .long L1
+ // .long 0x01010001
+ // .quad 0
+ // .quad 0
+ //
+ // # compact unwind for _bar
+ // .quad _bar
+ // .set L2,LbarEnd-_bar
+ // .long L2
+ // .long 0x01020011
+ // .quad __gxx_personality
+ // .quad except_tab1
+
+ // Range Start
+ EmitSymbol(Streamer, *Frame.Begin, FDEEncoding);
+
+ // Range Length
+ const MCExpr *Range = MakeStartMinusEndExpr(Streamer, *Frame.Begin,
+ *Frame.End, 0);
+ Streamer.EmitAbsValue(Range, Size);
+
+ return true;
+#endif
+}
+
const MCSymbol &FrameEmitterImpl::EmitCIE(MCStreamer &streamer,
const MCSymbol *personality,
unsigned personalityEncoding,
@@ -846,7 +901,8 @@
MCContext &context = streamer.getContext();
const TargetAsmInfo &asmInfo = context.getTargetAsmInfo();
const MCSection §ion = isEH ?
- *asmInfo.getEHFrameSection() : *asmInfo.getDwarfFrameSection();
+ *asmInfo.getEHFrameSection() :
+ *asmInfo.getDwarfFrameSection();
streamer.SwitchSection(§ion);
MCSymbol *SectionStart = context.CreateTempSymbol();
streamer.EmitLabel(SectionStart);
@@ -861,11 +917,17 @@
CIEKey key(frame.Personality, frame.PersonalityEncoding,
frame.LsdaEncoding);
const MCSymbol *&cieStart = isEH ? CIEStarts[key] : DummyDebugKey;
+ if (isEH && asmInfo.getSupportsCompactUnwindInfo() &&
+ Emitter.EmitCompactUnwind(streamer, frame))
+ continue;
+
if (!cieStart)
cieStart = &Emitter.EmitCIE(streamer, frame.Personality,
frame.PersonalityEncoding, frame.Lsda,
frame.LsdaEncoding);
+
fdeEnd = Emitter.EmitFDE(streamer, *cieStart, frame);
+
if (i != n - 1)
streamer.EmitLabel(fdeEnd);
}
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