Also added the defaults for whether to generate this load command, which
the cmdline options are able to override.
There was also a difference to ld64 which is fixed here in that ld64 will
generate an empty data in code command if requested.
rdar://problem/24472630
llvm-svn: 260191
This load command generates data in the LINKEDIT section which
is a list of ULEB128 delta's to all of the functions in the __text section.
It is then 0 terminated and pointer aligned to pad.
ld64 exposes the -function-starts and no-function-starts cmdline options
to override behaviour from the defaults based on file types.
rdar://problem/24472630
llvm-svn: 260188
This was a bug in our handling of these symbols compared to ld64.
Turns out that ld64 always marks these symbols as being not dead stripped.
llvm-svn: 260185
The atom content type enum is used as a tie breaker to sort atoms.
In that case, we want MachHeader to be before typeCode as it really will
be before the code in the final executable.
Test case to follow in the next commit or two.
llvm-svn: 260184
I found that the handling of 'L' character in an augmentation string is
wrong because 'L' means that the next byte is the length field. I could
have fixed that by just skipping the next byte, but I decided to take a
different approach.
Teaching the linker about all the types of CIE internal records just to
skip them is silly. And the code doing that is not actually executed now
(that's why the bug did not cause any issue.) It is because the 'R' field,
which we want to read, is always at beginning of the CIE. So I reduced
the code dramatically by assuming that that's always the case. I want to
see how it works in the wild. If it doesn't work, we can roll this back
(with a fix for 'L').
http://reviews.llvm.org/D16939
llvm-svn: 260073
The initial segment protection was also being used to set the maximum
segment protection level. Instead, the maximum should be set according
to the architecture we are linking. For example on Mac OS it should be
RWX on most pages, but on iOS is often on R_X.
rdar://problem/24515136
llvm-svn: 259966
We currently tag on a "__LINKEDIT" when we are emitting the segments.
However, an upcoming patch aims to set the initprot and maxprot segment members
to their correct values, and in order to share code, its better to create this
segment for real and handle it in buildFileOffsets the same way ld64 does.
The commit for segment protections will add a test for this all being correct so
no test here until that code is committed.
llvm-svn: 259960
I removed "CIE/FIE size is too large" error because that was not
checking for correct error conditions. [UINT_MAX - 4, UINT_MAX) is
a correct range as a size of a CIE/FDE record. It's just that the
size cannot be larger than the section size.
llvm-svn: 259951
Previously, it was easy to leave some Out<ELFT> fields uninitialized
because assignments to the fields are mixed with output section
instantiations. In this patch, I separate initializations from assignments
to improve readability.
http://reviews.llvm.org/D16864
llvm-svn: 259899
The variable was marking various cases where a symbol must be included
in the dynamic symbol table. Being used by a dynamic relocation was only
one of them.
llvm-svn: 259889
The previous names contained "Local" and "Current", but what we
are handling is always local and current, so they were redundant.
TlsIndex comes from "tls_index" struct that Ulrich Drepper is using
in this document to describe this data structure in GOT.
llvm-svn: 259852
Summary:
LLVM3.3 (and earlier) would fail to include a relocation section in
the group that the section it was relocating is in. Object files
affected by this issue have been encountered in the wild when using LLD.
This would result in a siutation like:
Section {
Index: 5
Name: .text._Z3fooIiEvv (6)
Type: SHT_PROGBITS (0x1)
Flags [ (0x206)
SHF_ALLOC (0x2)
SHF_EXECINSTR (0x4)
SHF_GROUP (0x200)
]
Address: 0x0
Offset: 0x48
Size: 5
Link: 0
Info: 0
AddressAlignment: 1
EntrySize: 0
}
Section {
Index: 6
Name: .rela.text._Z3fooIiEvv (1)
Type: SHT_RELA (0x4)
Flags [ (0x0)
]
Address: 0x0
Offset: 0x3F0
Size: 24
Link: 8
Info: 5
AddressAlignment: 8
EntrySize: 24
}
In LLD, during symbol resolution, we discard the section containing the
weak symbol, but this amounts to replacing it with
InputSection<ELFT>::Discarded.
When we later saw the corresponding relocation section, we would then
end up pusing onto InputSection<ELFT>::Discarded.RelocSections, which is
bogus.
Reviewers: ruiu, rafael
Subscribers: llvm-commits, Bigcheese
Differential Revision: http://reviews.llvm.org/D16898
llvm-svn: 259831
Another case where we currently have almost duplicated code is the
creation of dynamic relocations. First to decide if we need one, then to
decide what to write.
This patch fixes it by passing more information from the relocation scan
to the section writing code. This is the same idea used for r258723.
I actually think it should be possible to simplify this further by
reordering things a bit in the writer. For example, we should be able to
represent almost every position in the file with an OutputSeciton and
offset. When writing it out we then just need to add the offset to the
OutputSection VA.
llvm-svn: 259829
On Mac OS 10.5 and later, with X86_64 and outputting a dynamic executable,
ld64 set the CPU_SUBTYPE_LIB64 mask on the cpusubtype in the mach_header.
This adds the same functionality to lld.
rdar://problem/24507177
llvm-svn: 259826
Symbol does not need an entry i the 'global' part of GOT if it cannot be
preempted. So canBePreempted fully satisfies us at least for now.
llvm-svn: 259779
If relocation against symbol requires GOT entry creation and this symbol
is defined in DSO, the GOT entry should be created in the 'global' part
of the GOT even if we link executable file. Also we do not need to create
a dynamic symbol table entry for global symbol corresponding to the
local GOT entry.
llvm-svn: 259778
This is of the form A.B.C.D.E and to match ld64's behaviour, is
always output to files, even when the version is 0.
rdar://problem/24472630
llvm-svn: 259746
ld64 sets both S_ATTR_PURE_INSTRUCTIONS and S_ATTR_SOME_INSTRUCTIONS
on __TEXT, __text. We only had the S_ATTR_PURE_INSTRUCTIONS attribute.
rdar://problem/24495801
llvm-svn: 259744
In the case where we are emitting to an object file, the platform is
possibly unknown, and the source object files contained load commands
for version min, we can take the maximum of those min versions and
emit in in the output object file.
This test also tests r259739.
llvm-svn: 259742
Defaulting to unknown matches ld64, but it also makes sure that all
of our code can handle not knowing the platform. For example, a later
commit will add support for version min load commands with an unknown
platform, which is a feature supported by ld64.
No test case here. The next commit will have one with the version min
code that needed this patch.
llvm-svn: 259739
This option is emitted in the min_version load commands.
Note, there's currently a difference in behaviour compared to ld64 in
that we emit a warning if we generate a min_version load command and
didn't give an sdk_version. We need to decide what the correct behaviour
is here as its possible we want to emit an error and force clients to
provide the option.
llvm-svn: 259729
If the command line contains something like -macosx_version_min and we
don't explicitly disable generation with -no_version_load_command then
we generate the LC_VERSION_MIN command in the output file.
There's a couple of FIXME's in here. These will be handled soon with
more tests but I didn't want to grow this patch any more than it already was.
rdar://problem/24472630
llvm-svn: 259718
On some Windows environment, this test did not fail, because opening NUL
with FileOutputBuffer didn't fail. Thanks to George Rimar for reporting.
llvm-svn: 259669
It can fail to open an output file for various reasons, including
lack of permission, too long filename, or the output file is not
a mmap'able file.
llvm-svn: 259596
In r259574 I fixed some of the issues with the mach header symbols
and DSO handles.
This is the next issue whereby the __mh_execute_header has to not
be dead stripped, and (to match ld64) should be dynamically referenced.
The test here should also have been added in r259574 to make sure that
we emit this symbol. But checking that it is not only emitted but also
has the correct reference type is fine.
llvm-svn: 259589
NAKAMURA Takumi