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| author | Oliver Stannard <oliver.stannard@arm.com> | 2014-06-19 15:39:33 +0000 |
|---|---|---|
| committer | Oliver Stannard <oliver.stannard@arm.com> | 2014-06-19 15:39:33 +0000 |
| commit | f7693f4c1f80e2ad4f14b4c2876b2ad5c59f39b2 (patch) | |
| tree | 2a6422550cbe856f1a40b1cef3350ba150450832 /llvm/lib | |
| parent | 4f7ef8c6ef1e33e1eb89f7793d7ed630578b7db7 (diff) | |
| download | bcm5719-llvm-f7693f4c1f80e2ad4f14b4c2876b2ad5c59f39b2.tar.gz bcm5719-llvm-f7693f4c1f80e2ad4f14b4c2876b2ad5c59f39b2.zip | |
Emit DWARF3 call frame information when DWARF3+ debug info is requested
Currently, llvm always emits a DWARF CIE with a version of 1, even when emitting
DWARF 3 or 4, which both support CIE version 3. This patch makes it emit the
newer CIE version when we are emitting DWARF 3 or 4. This will not reduce
compatibility, as we already emit other DWARF3/4 features, and is worth doing as
the DWARF3 spec removed some ambiguities in the interpretation of call frame
information.
It also fixes a minor bug where the "return address" field of the CIE was
encoded as a ULEB128, which is only valid when the CIE version is 3. There are
no test changes for this, because (as far as I can tell) none of the platforms
that we test have a return address register with a DWARF register number >127.
llvm-svn: 211272
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 2 | ||||
| -rw-r--r-- | llvm/lib/MC/MCDwarf.cpp | 14 |
2 files changed, 14 insertions, 2 deletions
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp index 7aaf731b6f8..3847eb124f3 100644 --- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp +++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp @@ -209,6 +209,8 @@ DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M) DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber : MMI->getModule()->getDwarfVersion(); + Asm->OutStreamer.getContext().setDwarfVersion(DwarfVersion); + { NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); beginModule(); diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp index be6731abedd..1016466839f 100644 --- a/llvm/lib/MC/MCDwarf.cpp +++ b/llvm/lib/MC/MCDwarf.cpp @@ -1270,7 +1270,10 @@ const MCSymbol &FrameEmitterImpl::EmitCIE(MCObjectStreamer &streamer, // Version if (verboseAsm) streamer.AddComment("DW_CIE_VERSION"); - streamer.EmitIntValue(dwarf::DW_CIE_VERSION, 1); + // For DWARF2, we use CIE version 1 + // For DWARF3+, we use CIE version 3 + uint8_t CIEVersion = context.getDwarfVersion() <= 2 ? 1 : 3; + streamer.EmitIntValue(CIEVersion, 1); // Augmentation String SmallString<8> Augmentation; @@ -1298,7 +1301,14 @@ const MCSymbol &FrameEmitterImpl::EmitCIE(MCObjectStreamer &streamer, // Return Address Register if (verboseAsm) streamer.AddComment("CIE Return Address Column"); - streamer.EmitULEB128IntValue(MRI->getDwarfRegNum(MRI->getRARegister(), true)); + if (CIEVersion == 1) { + assert(MRI->getRARegister() <= 255 && + "DWARF 2 encodes return_address_register in one byte"); + streamer.EmitIntValue(MRI->getDwarfRegNum(MRI->getRARegister(), true), 1); + } else { + streamer.EmitULEB128IntValue( + MRI->getDwarfRegNum(MRI->getRARegister(), true)); + } // Augmentation Data Length (optional) |
