The fix itself is fairly simple: move getAccessVariant to MCValue so that we
replace the old weak expression evaluation with the far more general
EvaluateAsRelocatable.
This then requires that EvaluateAsRelocatable stop when it finds a non
trivial reference kind. And that in turn requires the ELF writer to look
harder for weak references.
Last but not least, this found a case where we were being bug by bug
compatible with gas and accepting an invalid input. I reported pr19647
to track it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207920 91177308-0d34-0410-b5e6-96231b3b80d8
With this MC is able to handle _GLOBAL_OFFSET_TABLE_ in 64 bit mode, which is
needed for medium and large code models.
This fixes pr19470.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206793 91177308-0d34-0410-b5e6-96231b3b80d8
This allows correct relocations to be generated for a symbolic
address that is being adjusted by a negative constant. Since r204294,
such expressions have triggered undefined behavior when LLVM was built
without assertions.
Credit goes to Rafael for this patch; I'm submitting it on his behalf
as he is on vacation this week.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206192 91177308-0d34-0410-b5e6-96231b3b80d8
Given
bar = foo + 4
.long bar
MC would eat the 4. GNU as includes it in the relocation. The rule seems to be
that a variable that defines a symbol is used in the relocation and one that
does not define a symbol is evaluated and the result included in the relocation.
Fixing this unfortunately required some other changes:
* Since the variable is now evaluated, it would prevent the ELF writer from
noticing the weakref marker the elf streamer uses. This patch then replaces
that with a VariantKind in MCSymbolRefExpr.
* Using VariantKind then requires us to look past other VariantKind to see
.weakref bar,foo
call bar@PLT
doing this also fixes
zed = foo +2
call zed@PLT
so that is a good thing.
* Looking past VariantKind means that the relocation selection has to use
the fixup instead of the target.
This is a reboot of the previous fixes for MC. I will watch the sanitizer
buildbot and wait for a build before adding back the previous fixes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204294 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
LLVM would crash when trying to come up with a relocation type for
assembly like:
movabsq $V@TPOFF, %rax
Instead, we say the relocation type is R_X86_64_TPOFF64.
Fixes PR17274.
Reviewers: dblaikie, nrieck, rafael
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1717
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191163 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182908 91177308-0d34-0410-b5e6-96231b3b80d8
gun as does. This makes it a lot easier to compare the output of both
as the addresses are now a lot closer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127972 91177308-0d34-0410-b5e6-96231b3b80d8
The failures in r116753 r116756 were caused by a python issue -
Python likes to append 'L' suffix to stringified numbers if the number
is larger than a machine int. Unfortunately, this causes a divergence of
behavior between 32 and 64 bit python versions.
I re-crafted elf-dump/common_dump to take care of these issues by:
1. always printing 0x (makes for easy sed/regex)
2. always print fixed length (exactly 2 + numBits/4 digits long)
by mod ((2^numBits) - 1)
3. left-padded with '0'
There is a residual common routine that is also used by
macho-dump (dataToHex) , so I left the 'section_data' test values alone.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116823 91177308-0d34-0410-b5e6-96231b3b80d8
With this patch in
movq $foo, foo(%rip)
foo:
.long foo
We produce a R_X86_64_32S for the first relocation and R_X86_64_32 for the
second one.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115134 91177308-0d34-0410-b5e6-96231b3b80d8
