When updating an existing archive, llvm-ar opens the old archive into a
`MemoryBuffer`, does its thing, and writes the results to a temporary
file. That file is then renamed to the original archive filename, thus
replacing it with the updated contents. However, on Windows at least,
what would happen is that the `MemoryBuffer` for the old archive would
actually be an mmap'ed view of the file, so when it came time to do the
rename via Win32's `ReplaceFile`, it would succeed but would be unable
to fully replace the file since there would still be a handle open on
it; instead, the old version got renamed to a random temporary name and
left behind.
Patch by Cameron!
llvm-svn: 268916
Produce the first specific error message for a malformed Mach-O file describing
the problem instead of the generic message for object_error::parse_failed of
"Invalid data was encountered while parsing the file”. Many more good error
messages will follow after this first one.
This is built on Lang Hames’ great work of adding the ’Error' class for
structured error handling and threading Error through MachOObjectFile
construction. And making createMachOObjectFile return Expected<...> .
So to to get the error to the llvm-obdump tool, I changed the stack of
these methods to also return Expected<...> :
object::ObjectFile::createObjectFile()
object::SymbolicFile::createSymbolicFile()
object::createBinary()
Then finally in ParseInputMachO() in MachODump.cpp the error can
be reported and the specific error message can be printed in llvm-objdump
and can be seen in the existing test case for the existing malformed binary
but with the updated error message.
Converting these interfaces to Expected<> from ErrorOr<> does involve
touching a number of places. To contain the changes for now use of
errorToErrorCode() and errorOrToExpected() are used where the callers
are yet to be converted.
Also there some were bugs in the existing code that did not deal with the
old ErrorOr<> return values. So now with Expected<> since they must be
checked and the error handled, I added a TODO and a comment:
“// TODO: Actually report errors helpfully” and a call something like
consumeError(ObjOrErr.takeError()) so the buggy code will not crash
since needed to deal with the Error.
Note there is one fix also needed to lld/COFF/InputFiles.cpp that goes along
with this that I will commit right after this. So expect lld not to built
after this commit and before the next one.
llvm-svn: 265606
We always create archives with just he filename as the member name, but
other archives can put a more complicated path in there.
This patches handles it by computing just the filename as we do when
adding a new member.
If storing the path is important for some reason, we should probably
have an orthogonal option for doing that and do it for both old and new
members.
Fixes pr25877.
llvm-svn: 256001
The needed lld matching changes to be submitted immediately next,
but this revision will cause lld failures with this alone which is expected.
This removes the eating of the error in Archive::Child::getSize() when the characters
in the size field in the archive header for the member is not a number. To do this we
have all of the needed methods return ErrorOr to push them up until we get out of lib.
Then the tools and can handle the error in whatever way is appropriate for that tool.
So the solution is to plumb all the ErrorOr stuff through everything that touches archives.
This include its iterators as one can create an Archive object but the first or any other
Child object may fail to be created due to a bad size field in its header.
Thanks to Lang Hames on the changes making child_iterator contain an
ErrorOr<Child> instead of a Child and the needed changes to ErrorOr.h to add
operator overloading for * and -> .
We don’t want to use llvm_unreachable() as it calls abort() and is produces a “crash”
and using report_fatal_error() to move the error checking will cause the program to
stop, neither of which are really correct in library code. There are still some uses of
these that should be cleaned up in this library code for other than the size field.
The test cases use archives with text files so one can see the non-digit character,
in this case a ‘%’, in the size field.
These changes will require corresponding changes to the lld project. That will be
committed immediately after this change. But this revision will cause lld failures
with this alone which is expected.
llvm-svn: 252192
in the size field in the archive header for the member is not a number. To do this we
have all of the needed methods return ErrorOr to push them up until we get out of lib.
Then the tools and can handle the error in whatever way is appropriate for that tool.
So the solution is to plumb all the ErrorOr stuff through everything that touches archives.
This include its iterators as one can create an Archive object but the first or any other
Child object may fail to be created due to a bad size field in its header.
Thanks to Lang Hames on the changes making child_iterator contain an
ErrorOr<Child> instead of a Child and the needed changes to ErrorOr.h to add
operator overloading for * and -> .
We don’t want to use llvm_unreachable() as it calls abort() and is produces a “crash”
and using report_fatal_error() to move the error checking will cause the program to
stop, neither of which are really correct in library code. There are still some uses of
these that should be cleaned up in this library code for other than the size field.
Also corrected the code where the size gets us to the “at the end of the archive”
which is OK but past the end of the archive will return object_error::parse_failed now.
The test cases use archives with text files so one can see the non-digit character,
in this case a ‘%’, in the size field.
llvm-svn: 250906
It looks like ld64 requires it. With this we seem to be able to bootstrap using
llvm-ar+/usr/bin/true instead of ar+ranlib (currently on stage2).
llvm-svn: 241842
The gnu ar format uses BE numbers. The BSD one uses LE. Add a helper for one or the
other. NFC for now, just removes some noise from the following patch.
llvm-svn: 241808
No support for the symbol table yet (but will hopefully add it today).
We always use the long filename format so that we can align the member,
which is an advantage of the BSD format.
llvm-svn: 241721
As noted on Errc.h:
// * std::errc is just marked with is_error_condition_enum. This means that
// common patters like AnErrorCode == errc::no_such_file_or_directory take
// 4 virtual calls instead of two comparisons.
And on some libstdc++ those virtual functions conclude that
------------------------
int main() {
std::error_code foo = std::make_error_code(std::errc::no_such_file_or_directory);
return foo == std::errc::no_such_file_or_directory;
}
-------------------------
should exit with 0.
llvm-svn: 239683
No functional change intended, other than some minor changes to certain
diagnostics.
Differential Revision: http://reviews.llvm.org/D10296
llvm-svn: 239278
Rafael Espindola