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
This patch includes a fix for a llvm-readobj test. With this patch,
the tool does no longer print out COFF headers for the short import
file, but that's probably desirable because the header for the short
import file is dummy.
llvm-svn: 246283
COFF short import files are special kind of files that contains only
DLL-exported symbol names. That's different from object files because
it has no data except symbol names.
This change implements a SymbolicFile interface for the short import
files so that symbol names can be accessed through that interface.
llvm-ar is now able to read the file and create symbol table entries
for short import files.
llvm-svn: 246276
This format is simply a regular object file with the bitcode stored in a
section named ".llvmbc", plus any number of other (non-allocated) sections.
One immediate use case for this is to accommodate compilation processes
which expect the object file to contain metadata in non-allocated sections,
such as the ".go_export" section used by some Go compilers [1], although I
imagine that in the future we could consider compiling parts of the module
(such as large non-inlinable functions) directly into the object file to
improve LTO efficiency.
[1] http://golang.org/doc/install/gccgo#Imports
Differential Revision: http://reviews.llvm.org/D4371
llvm-svn: 218078
I took a guess at the changes to the gold plugin, because that doesn't
seem to build by default for me. Not sure what dependencies I might be
missing for that.
llvm-svn: 217056
An unpleasant surprise while migrating unique_ptrs (see changes in
lib/Object): ErrorOr<int*> was implicitly convertible to
ErrorOr<std::unique_ptr<int>>.
Keep the explicit conversions otherwise it's a pain to convert
ErrorOr<int*> to ErrorOr<std::unique_ptr<int>>.
I'm not sure if there should be more SFINAE on those explicit ctors (I
could check if !is_convertible && is_constructible, but since the ctor
has to be called explicitly I don't think there's any need to disable
them when !is_constructible - they'll just fail anyway. It's the
converting ctors that can create interesting ambiguities without proper
SFINAE). I had to SFINAE the explicit ones because otherwise they'd be
ambiguous with the implicit ones in an explicit context, so far as I
could tell.
The converting assignment operators seemed unnecessary (and similarly
buggy/dangerous) - just rely on the converting ctors to convert to the
right type for assignment instead.
llvm-svn: 217048
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
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
This allows us to just use a std::unique_ptr to store the pointer to the buffer.
The flip side is that they have to support releasing the buffer back to the
caller.
Overall this looks like a more efficient and less brittle api.
llvm-svn: 211542
This interface allows IRObjectFile to be implemented without having dummy
methods for all section and segment related methods.
Both llvm-ar and llvm-nm are changed to use it. Unfortunately the mangler is
still not plugged in since it requires some refactoring to make a Module hold
a DataLayout.
llvm-svn: 201881
Kevin Enderby