identify_magic is not free, so we should avoid calling it twice. The argument
also makes it cheap for createBinary to just forward to createObjectFile.
llvm-svn: 199813
The constructors of classes deriving from Binary normally take an error_code
as an argument to the constructor. My original intent was to change them
to have a trivial constructor and move the initial parsing logic to a static
method returning an ErrorOr. I changed my mind because:
* A constructor with an error_code out parameter is extremely convenient from
the implementation side. We can incrementally construct the object and give
up when we find an error.
* It is very efficient when constructing on the stack or when there is no
error. The only inefficient case is where heap allocating and an error is
found (we have to free the memory).
The result is that this is a much smaller patch. It just standardizes the
create* helpers to return an ErrorOr.
Almost no functionality change: The only difference is that this found that
we were trying to read past the end of COFF import library but ignoring the
error.
llvm-svn: 199770
Some background: One can pass compiled resource files (.res files) directly
to the linker on Windows. If a resource file is given, the linker will run
"cvtres" command in background to convert the resource file to a COFF file
to link it.
What I'm trying to do with this patch is to make the linker to recognize
the resource file by file magic, so that it can run cvtres command.
Differential Revision: http://llvm-reviews.chandlerc.com/D1943
llvm-svn: 192742
The Binary constructor takes ownership of the memory buffer. This is a fairly
unfortunate interface, but for now make createObjectFile consistent with it
by also deleting the buffer if it fails.
Fixes a leak in llvm-ar found by the valgrind bots.
llvm-svn: 187039
For COFF and MachO, sections semantically have relocations that apply to them.
That is not the case on ELF.
In relocatable objects (.o), a section with relocations in ELF has offsets to
another section where the relocations should be applied.
In dynamic objects and executables, relocations don't have an offset, they have
a virtual address. The section sh_info may or may not point to another section,
but that is not actually used for resolving the relocations.
This patch exposes that in the ObjectFile API. It has the following advantages:
* Most (all?) clients can handle this more efficiently. They will normally walk
all relocations, so doing an effort to iterate in a particular order doesn't
save time.
* llvm-readobj now prints relocations in the same way the native readelf does.
* probably most important, relocations that don't point to any section are now
visible. This is the case of relocations in the rela.dyn section. See the
updated relocation-executable.test for example.
llvm-svn: 182908
For regular object files this is only meaningful for common symbols. An object
file format with direct support for atoms should be able to provide alignment
information for all symbols.
This replaces getCommonSymbolAlignment and fixes
test-common-symbols-alignment.ll on darwin. This also includes a fix to
MachOObjectFile::getSymbolFlags. It was marking undefined symbols as common
(already tested by existing mcjit tests now that it is used).
llvm-svn: 180736
politely report it instead of running into llvm_unreachable.
Also patch llvm-dwarfdump to actually check whether the file it's attempting to
dump is a valid object file.
llvm-svn: 173489
