lld shouldn't directly use the COFF header nor should it use raw
coff_symbols. Instead, query the header properties from the
COFFObjectFile and use COFFSymbolRef to abstractly reference COFF
symbols.
This is just enough to get lld compiling with the changes to
llvm::object. Bigobj specific testing will come later.
Differential Revision: http://reviews.llvm.org/D5280
llvm-svn: 217497
I hope this is the last fix for x64 relocations as I've wasted
a few days on this.
This caused a mysterious issue that some C++ programs crash on
startup. It was because a null pointer is passed as argv to main.
__tmainCRTStartup calls main, but before that it calls all
initialization routines between .text$xc_a and .text$xc_z.
pre_cpp_init is one of such routines, and it is the one who
initializes a heap pointer for argv for later use. That routine
was not called for some reason.
It turned out that __tmainCRTStartup was skipping a block of
code because of the relocation bug. A condition in the function
depends on a memory load, and that memory load was referring
a wrong location. As a result a jump instruction took the
wrong branch, skipping pre_cpp_init and so on.
This patch fixes the issue. Also added more tests to fix them
once and for all.
llvm-svn: 216772
When a relocation is applied to a location, the new value needs
to be added to the existing value at the location. Existing
value is in most cases zero, but if not, the current code does
not work.
llvm-svn: 216680
Image Base field in the PE/COFF header is used as hint for the loader.
If the loader can load the executable at the specified address, that's
fine, but if not, it has to load it at a different address.
If that happens, the loader has to fix up the addresses in the
executable by adding the offset. The list of addresses that need to
be fixed is in .reloc section.
This patch is to emit x64 .reloc section contents.
llvm-svn: 216636
IMAGE_REL_AMD64_ADDR64 relocation should set 64-bit *VA* (virtual
address) instead of *RVA* (relative virtual address), so we have
to add the iamge base to the target's RVA.
llvm-svn: 216512
The implementation of AMD64 relocations was imcomplete
and wrong. On AMD64, we of course have to use AMD64
relocations instead of i386 ones. This patch fixes the
issue.
LLD is now able to link hello64.obj (created from
hello64.asm) against user32.lib and kernel32.lib to
create a Win64 binary.
llvm-svn: 216253
/INCLUDE arguments passed as command line options are handled in the
same way as Unix -u. All option values are converted to an undefined
symbol and added to a dummy input file, so that the specified symbols
are resolved.
One tricky thing on Windows is that the option is also allowed to
appear in the object file's directive section. At the time when
it's being read, all (regular) command line options have already
been processed. We cannot add undefined atoms to the dummy file
anymore.
Previously, we added such /INCLUDE to a set that has already been
processed. As a result the options were ignored.
This patch fixes the issue. Now, /INCLUDE symbols in the directive
section are handled as real undefined symbol in the COFF file.
We create an undefined symbol for each /INCLUDE argument and add
it to the file being parsed.
llvm-svn: 214824
The PE/COFF spec says that SizeOfRawData field in the section
header must be a multiple of FileAlignment from the optional
header. LLD emits 512 as FileAlignment, so it must have been
a multiple of 512.
LLD did not follow that. It emitted the actual section size
without the last padding as the SizeOfRawData. Although it's
not correct as per the spec, the Windows loader doesn't seem
to actually bother to check that. Executables created by LLD
worked fine.
However, tools dealing with executalbe files may expect it
to be the correct value, and one instance of it is mt.exe
tool distributed as a part of Windows SDK.
If CMake is invoked with "-E vs_link_exe" option, it silently
run mt.exe to embed a resource file to the resulting file.
And mt.exe sometimes breaks an input file if it's section
header does not follow the standard. That caused a misterous
error that CMake with Ninja occasionally produces a broken
executable.
This patch fixes the section header to make mt.exe and
other tools happy.
llvm-svn: 214453
The entry point file needs to be processed after all other
object files and before all .lib files. It was processed
after .lib files. That caused an issue that the entry point
function was not resolved from the standard library files.
llvm-svn: 213804
On Windows there are four "main" functions -- main, wmain, WinMain,
or wWinMain. Their parameter types are diffferent. The standard
library provides four different entry functions (i.e.
{w,}{WinMain,main}CRTStartup) for them. You need to use the right
entry routine for your "main" function.
If you give an /entry option, the specified name is used
unconditionally.
Otherwise, the linker needs to select the right one based on
user-supplied entry point function. This can be done after the
linker reads all the input files.
This patch moves the code to determine the entry point function
from the driver to a virtual input file. It also implements the
correct logic for the entry point function selection.
llvm-svn: 213713
The code to manage resolvable symbols is now separated from
ExportedSymbolRenameFile so that other class can reuse it.
I'm planning to use it to find the entry function symbol
based on resolvable symbols.
llvm-svn: 213322
Previously we invoked cvtres.exe for each compiled Windows
resource file. The generated files were then concatenated
and embedded to the executable.
That was not the correct way to merge compiled Windows
resource files. If you just concatenate generated files,
only the first file would be recognized and the rest would
be ignored as trailing garbage.
The right way to merge them is to call cvtres.exe with
multiple input files. In this patch we do that in the
Windows driver.
llvm-svn: 212763
Previously the alignment of the .bss section was not
properly set because of a bug in AtomizeDefinedSymbolsInSection.
We set the alignment of the section at the end of the function,
but we use an eraly return for the .bss section, so the code had
been skipped.
llvm-svn: 212571
COFF supports a feature similar to ELF's section groups. This
patch implements it.
In ELF, section groups are identified by their names, and they are
treated somewhat differently from regular symbols. In COFF, the
feature is realized in a more straightforward way. A section can
have an annotation saying "if Nth section is linked, link this
section too."
I added a new reference type, kindAssociate. If a target atom is
coalesced away, the referring atom is removed by Resolver, so that
they are treated as a group.
Differential Revision: http://reviews.llvm.org/D4028
llvm-svn: 211106
COFF supports a feature similar to ELF's section groups. This
patch implements it.
In ELF, section groups are identified by their names, and they are
treated somewhat differently from regular symbols. In COFF, the
feature is realized in a more straightforward way. A section can
have an annotation saying "if Nth section is linked, link this
section too."
Implementing such feature is easy. We can add a reference from a
target atom to an original atom, so that if the target is linked,
the original atom is also linked. If not linked, both will be
dead-stripped. So they are treated as a group.
I added a new reference type, kindAssociate. It does nothing except
preventing referenced atoms from being dead-stripped.
No change to the Resolver is needed.
Reviewers: Bigcheese, shankarke, atanasyan
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D3946
llvm-svn: 210240
