6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-09-24 23:28:41 +00:00
Code Issues Projects Releases Wiki Activity

Emit DWARF3 call frame information when DWARF3+ debug info is requested

Browse Source 
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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211272 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Oliver Stannard
2014-06-19 15:39:33 +00:00
parent 7e40983328
commit bb804ee909
29 changed files with 132 additions and 74 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
lib/MC/MCDwarf.cpp
View File

@@ -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)