Commit Graph

5 Commits

Author SHA1 Message Date
Georgii Rymar 2e365ca2f7 [DebugInfo/llvm-objdump] - Print "ZERO terminator" for terminator entries when dumping .eh_frame.
A CIE with the Length == 0 is a terminator:
https://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html

And GNU objdump recognizes them and prints the following for such entries:

"00000000 ZERO terminator"

This patch teaches llvm-objdump to do the same. I had to update tests to use
"CHECK-NEXT" too.

(Note: it looks perhaps not right that printing is done inside the DebugInfo library,
I'd expect to see the change in the llvm-objdump's code somewhere instead,
but that is how it done atm).

Differential revision: https://reviews.llvm.org/D80476
2020-05-26 12:52:42 +03:00
Georgii Rymar 2569787e44 [DebugInfo] - Fix multiple issues in DWARFDebugFrame::parse().
I've noticed an issue with "Data.getRelocatedValue(...)" call.

it might silently ignore an error when a content is truncated.
That leads to an infinite loop in the code (e.g. llvm-readobj hangs).

After fixing the issue I've found that actually we always tried
to read past the end of a section, even when a content was valid.
It happened because the terminator CIE (a CIE with the length == 0)
was never handled. At first I've tried just to stop adding the terminator
entry (and return), but it does not seem to be correct, because tools like
llvm-objdump might want to print something for such entries
(see comments in the code and test cases).

This patch fixes issues mentioned, provides new test cases for
both llvm-readobj and lib/DebugInfo and adds FIXMEs to existent
test cases related.

Differential revision: https://reviews.llvm.org/D80299
2020-05-26 12:13:13 +03:00
Fangrui Song 6ed18eaa77 [llvm-objdump][test] Change llvm-objdump tests to use double dash options 2020-03-15 16:01:26 -07:00
Igor Kudrin 2ba4df6c11 [DebugInfo] Fix dumping CIE ID in .eh_frame sections.
We do not keep the actual value of the CIE ID field, because it is
predefined, and use a constant when dumping a CIE record. The issue
was that the predefined value is different for .debug_frame and
.eh_frame sections, but we always printed the one which corresponds
to .debug_frame. The patch fixes that by choosing an appropriate
constant to print.

See the following for more information about .eh_frame sections:
https://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html

Differential Revision: https://reviews.llvm.org/D73627
2020-02-13 15:42:14 +07:00
Igor Laevsky ff291b5833 [DebugInfo] Support zero-length CIE in the _eh_frame parser
MCJIT emits zero-length CIE at the end of the _eh_frame section. This change
ensures that parser inside DebugInfo will not crash and correctly record such cases.
We are now recording DW_EH_PE_omit as a default value for FDE and LSDA encodings.
Also Offset != EndAugmentationOffset assertion check will only happen if augmentation 
string had 'z' letter in it.

Differential Revision: http://reviews.llvm.org/D16588

llvm-svn: 258931
2016-01-27 14:05:35 +00:00