DebugInfo: Support for compressed debug info sections
1) When creating a .debug_* section and instead create a .zdebug_
section.
2) When creating a fragment in a .zdebug_* section, make it a compressed
fragment.
3) When computing the size of a compressed section, compress the data
and use the size of the compressed data.
4) Emit the compressed bytes.
Also, check that only if a section has a compressed fragment, then that
is the only fragment in the section.
Assert-fail if the fragment's data is modified after it is compressed.
Initial review on llvm-commits by Eric Christopher and Rafael Espindola.
llvm-svn: 204958
diff --git a/llvm/lib/MC/MCObjectStreamer.cpp b/llvm/lib/MC/MCObjectStreamer.cpp
index 809cb11..35786ac 100644
--- a/llvm/lib/MC/MCObjectStreamer.cpp
+++ b/llvm/lib/MC/MCObjectStreamer.cpp
@@ -20,6 +20,7 @@
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/ErrorHandling.h"
+#include "llvm/MC/MCSectionELF.h"
using namespace llvm;
MCObjectStreamer::MCObjectStreamer(MCContext &Context, MCAsmBackend &TAB,
@@ -63,7 +64,11 @@
// When bundling is enabled, we don't want to add data to a fragment that
// already has instructions (see MCELFStreamer::EmitInstToData for details)
if (!F || (Assembler->isBundlingEnabled() && F->hasInstructions())) {
- F = new MCDataFragment();
+ const auto *Sec = dyn_cast<MCSectionELF>(&getCurrentSectionData()->getSection());
+ if (Sec && Sec->getSectionName().startswith(".zdebug_"))
+ F = new MCCompressedFragment();
+ else
+ F = new MCDataFragment();
insert(F);
}
return F;