Summary:
On macOS 11, the libraries that have been integrated in the system
shared cache are not present on the filesystem anymore. LLDB was
using those files to get access to the symbols of those libraries.
LLDB can get the images from the target process memory though.
This has 2 consequences:
- LLDB cannot load the images before the process starts, reporting
an error if someone tries to break on a system symbol.
- Loading the symbols by downloading the data from the inferior
is super slow. It takes tens of seconds at the start of the
debug session to populate the Module list.
To fix this, we can use the library images LLDB has in its own
mapping of the shared cache. Shared cache images are somewhat
special as their LINKEDIT segment is moved to the end of the cache
and thus the images are not contiguous in memory. All of this can
hidden in ObjectFileMachO.
This patch fixes a number of test failures on macOS 11 due to the
first problem described above and adds some specific unittesting
for the new SharedCache Host utilities.
Reviewers: jasonmolenda, labath
Subscribers: llvm-commits, lldb-commits
Tags: #lldb, #llvm
Differential Revision: https://reviews.llvm.org/D83023
This patch adds an implementation of unwinding using PE EH info. It allows to
get almost ideal call stacks on 64-bit Windows systems (except some epilogue
cases, but I believe that they can be fixed with unwind plan disassembly
augmentation in the future).
To achieve the goal the CallFrameInfo abstraction was made. It is based on the
DWARFCallFrameInfo class interface with a few changes to make it less
DWARF-specific.
To implement the new interface for PECOFF object files the class PECallFrameInfo
was written. It uses the next helper classes:
- UnwindCodesIterator helps to iterate through UnwindCode structures (and
processes chained infos transparently);
- EHProgramBuilder with the use of UnwindCodesIterator constructs EHProgram;
- EHProgram is, by fact, a vector of EHInstructions. It creates an abstraction
over the low-level unwind codes and simplifies work with them. It contains
only the information that is relevant to unwinding in the unified form. Also
the required unwind codes are read from the object file only once with it;
- EHProgramRange allows to take a range of EHProgram and to build an unwind row
for it.
So, PECallFrameInfo builds the EHProgram with EHProgramBuilder, takes the ranges
corresponding to every offset in prologue and builds the rows of the resulted
unwind plan. The resulted plan covers the whole range of the function except the
epilogue.
Reviewers: jasonmolenda, asmith, amccarth, clayborg, JDevlieghere, stella.stamenova, labath, espindola
Reviewed By: jasonmolenda
Subscribers: leonid.mashinskiy, emaste, mgorny, aprantl, arichardson, MaskRay, lldb-commits, llvm-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D67347
llvm-svn: 374528
Summary:
This centralizes parsing of breakpad records, which was previously
spread out over ObjectFileBreakpad and SymbolFileBreakpad.
For each record type X there is a separate breakpad::XRecord class, and
an associated parse function. The classes just store the information in
the breakpad records in a more accessible form. It is up to the users to
determine what to do with that data.
This separation also made it possible to write some targeted tests for
the parsing code, which was previously unaccessible, so I write a couple
of those too.
Reviewers: clayborg, lemo, zturner
Reviewed By: clayborg
Subscribers: mgorny, fedor.sergeev, lldb-commits
Differential Revision: https://reviews.llvm.org/D56844
llvm-svn: 351541
Summary:
Problem:
There are three filelds in the ELF header - e_phnum, e_shnum, and e_shstrndx -
that could be bigger than 64K and therefore do not fit in 16 bits reserved for
them in the header. If this happens, pretty often there is a special section at
index 0 which contains their real values for these fields in the section header
in the fields sh_info, sh_size, and sh_link respectively.
Fix:
- Rename original fields in the header declaration. We want to have them around
just in case.
- Reintroduce these fields as 32-bit members at the end of the header. By default
they are initialized from the header in Parse() method.
- In Parse(), detect the situation when the header might have been extended into
section info #0 and try to read it from the same data source.
- ObjectFileELF::GetModuleSpecifications accesses some of these fields but the
original parse uses too small data source. Re-parse the header if necessary
using bigger data source.
- ProcessElfCore::CreateInstance uses header with potentially sentinel values,
but it does not access these fields, so a comment here is enough.
Reviewers: labath
Reviewed By: labath
Subscribers: davidb, lldb-commits, mgorny
Differential Revision: https://reviews.llvm.org/D29095
Author: Eugene Birukov <eugenebi@hotmail.com>
llvm-svn: 293714
Fred Riss