This adds support for reading the "bigobj" variant of COFF produced by
cl's /bigobj and mingw's -mbig-obj.
The most significant difference that bigobj brings is more than 2**16
sections to COFF.
bigobj brings a few interesting differences with it:
- It doesn't have a Characteristics field in the file header.
- It doesn't have a SizeOfOptionalHeader field in the file header (it's
only used in executable files).
- Auxiliary symbol records have the same width as a symbol table entry.
Since symbol table entries are bigger, so are auxiliary symbol
records.
Write support will come soon.
Differential Revision: http://reviews.llvm.org/D5259
llvm-svn: 217496
The code is buggy and barely tested. It is also mostly boilerplate.
(This includes MCObjectDisassembler, which is the interface to that
functionality)
Following an IRC discussion with Jim Grosbach, it seems sensible to just
nuke the whole lot of functionality, and dig it up from VCS if
necessary (I hope not!).
All of this stuff appears to have been added in a huge patch dump (look
at the timeframe surrounding e.g. r182628) where almost every patch
seemed to be untested and not reviewed before being committed.
Post-review responses to the patches were never addressed. I don't think
any of it would have passed pre-commit review.
I doubt anyone is depending on this, since this code appears to be
extremely buggy. In limited testing that Michael Spencer and I did, we
couldn't find a single real-world object file that wouldn't crash the
CFG reconstruction stuff. The symbolizer stuff has O(n^2) behavior and
so is not much use to anyone anyway. It seemed simpler to remove them as
a whole. Most of this code is boilerplate, which is the only way it was
able to scrape by 60% coverage.
HEADSUP: Modules folks, some files I nuked were referenced from
include/llvm/module.modulemap; I just deleted the references. Hopefully
that is the right fix (one was a FIXME though!).
llvm-svn: 216983
MachOObjectFile in lib/Object currently has no support for parsing the rebase,
binding, and export information from the LC_DYLD_INFO load command in final
linked mach-o images. This patch adds support for parsing the exports trie data
structure. It also adds an option to llvm-objdump to dump that export info.
I did the exports parsing first because it is the hardest. The information is
encoded in a trie structure, but the standard ObjectFile way to inspect content
is through iterators. So I needed to make an iterator that would do a
non-recursive walk through the trie and maintain the concatenation of edges
needed for the current string prefix.
I plan to add similar support in MachOObjectFile and llvm-objdump to
parse/display the rebasing and binding info too.
llvm-svn: 216808
Take a StringRef instead of a "const char *".
Take a "std::error_code &" instead of a "std::string &" for error.
A create static method would be even better, but this patch is already a bit too
big.
llvm-svn: 216393
The switch statement would never fire due to the preceding break statement. Also, the switch statement has a default label with no case labels. Simplified the code, and allow it to execute.
llvm-svn: 216346
Owning the buffer is somewhat inflexible. Some Binaries have sub Binaries
(like Archive) and we had to create dummy buffers just to handle that. It is
also a bad fit for IRObjectFile where the Module wants to own the buffer too.
Keeping this ownership would make supporting IR inside native objects
particularly painful.
This patch focuses in lib/Object. If something elsewhere used to own an Binary,
now it also owns a MemoryBuffer.
This patch introduces a few new types.
* MemoryBufferRef. This is just a pair of StringRefs for the data and name.
This is to MemoryBuffer as StringRef is to std::string.
* OwningBinary. A combination of Binary and a MemoryBuffer. This is needed
for convenience functions that take a filename and return both the
buffer and the Binary using that buffer.
The C api now uses OwningBinary to avoid any change in semantics. I will start
a new thread to see if we want to change it and how.
llvm-svn: 216002
file with -macho, the Mach-O specific object file parser option.
After some discussion I chose to do this implementation contained in the logic
of llvm-objdump’s MachODump.cpp using a second disassembler for thumb when
needed and with updates mostly contained in the MachOObjectFile class.
llvm-svn: 215931
Add header guards to files that were missing guards. Remove #endif comments
as they don't seem common in LLVM (we can easily add them back if we decide
they're useful)
Changes made by clang-tidy with minor tweaks.
llvm-svn: 215558
ARM bots (& others, I think, now that I look) were failing because we
were using incorrect printf-style format specifiers. They were wrong
on almost any platform, actually, just mostly harmlessly so.
llvm-svn: 215196
Also make the disassembler created with the Mach-O parser (the -m option)
pick up the Target specific attributes specified with -mattr option.
llvm-svn: 215032
The size of the uninitialized sections, like BSS, can exceed the size of
the object file.
Do not attempt to grab the contents of such sections.
llvm-svn: 212953
The new library is 150KB on a Release+Asserts build, so it is quiet a bit of
code that regular users of MC don't need to link with now.
llvm-svn: 212209
string_ostream is a safe and efficient string builder that combines opaque
stack storage with a built-in ostream interface.
small_string_ostream<bytes> additionally permits an explicit stack storage size
other than the default 128 bytes to be provided. Beyond that, storage is
transferred to the heap.
This convenient class can be used in most places an
std::string+raw_string_ostream pair or SmallString<>+raw_svector_ostream pair
would previously have been used, in order to guarantee consistent access
without byte truncation.
The patch also converts much of LLVM to use the new facility. These changes
include several probable bug fixes for truncated output, a programming error
that's no longer possible with the new interface.
llvm-svn: 211749
This makes the buffer ownership on error conditions very natural. The buffer
is only moved out of the argument if an object is constructed that now
owns the buffer.
llvm-svn: 211546
The idea of this patch is to turn llvm/Support/system_error.h into a
transitional header that just brings in the erorr_code api to the llvm
namespace. I will remove it shortly afterwards.
The cases where the general idea needed some tweaking:
* std::errc is a namespace in msvc, so we cannot use "using std::errc". I could
add an #ifdef, but there were not that many uses, so I just added std:: to
them in this patch.
* Template specialization had to be moved to the std namespace in this
patch set already.
* The msvc implementation of default_error_condition doesn't seem to
provide the same transformations as we need. Not too surprising since
the standard doesn't actually say what "equivalent" means. I fixed the
problem by keeping our old mapping and using it at error_code
construction time.
Despite these shortcomings I think this is still a good thing. Some reasons:
* The different implementations of system_error might improve over time.
* It removes 925 lines of code from llvm already.
* It removes 6313 bytes from the text segment of the clang binary when
it is built with gcc and 2816 bytes when building with clang and
libstdc++.
llvm-svn: 210687
Immutable DILineInfo doesn't bring any benefits and complicates
code. Also, use std::string instead of SmallString<16> for file
and function names - their length can vary significantly.
No functionality change.
llvm-svn: 206654
Since LLVM currently only supports WinCOFF, assume that the input is WinCOFF
rather than another type of COFF file (ECOFF/XCOFF). If the architecture is
detected as thumb (e.g. the file has a IMAGE_FILE_MACHINE_ARMNT magic) then use
a triple of thumbv7-windows.
This allows for objdump to properly handle WoA object files without having to
specify the target triple manually.
llvm-svn: 206446
This patch re-introduces the MCContext member that was removed from
MCDisassembler in r206063, and requires that an MCContext be passed in at
MCDisassembler construction time. (Previously the MCContext member had been
initialized in an ad-hoc fashion after construction). The MCCContext member
can be used by MCDisassembler sub-classes to construct constant or
target-specific MCExprs.
This patch updates disassemblers for in-tree targets, and provides the
MCRegisterInfo instance that some disassemblers were using through the
MCContext (previously those backends were constructing their own
MCRegisterInfo instances).
llvm-svn: 206241
Once the auxiliary fields relating to the filename have been inspected, any
following auxiliary fields need not be visited as they have been consumed (the
following fields comprise the filepath as a single unit).
Adjust the test to catch this even if ASAN is not enabled.
llvm-svn: 206190
Rather than switching behaviour on whether a previous symbol has an auxiliary
symbol record for the next count of elements, simply iterate over the auxiliary
symbols right after processing the current symbol entry. This makes the
behaviour much simpler to follow and similar to llvm-readobj and yaml2obj.
llvm-svn: 206146
If a filename is a multiple of 18 characters, there will be no null-terminator.
This will result in an invalid access by the constructed StringRef. Add a test
case to exercise this and fix that handling. Address this same vulnerability in
llvm-readobj as well.
llvm-svn: 206145
The auxiliary file records are contiguous and only contain the filename.
Construct a StringRef directly rather than copying to a temporary buffer.
Suggested by majnemer on IRC!
llvm-svn: 206139
Add support for file auxiliary symbol entries in COFF symbol tables. A COFF
symbol table with a FILE entry is followed by sizeof(__FILE__) / 18 auxiliary
symbol records which contain the filename. Read them and form the original
filename that the record contains. Then display the name in the output.
llvm-svn: 206126
