If an ELF relocation is pointed at an absolute address, it will have a symbol ID of zero.
RuntimeDyldELF::processRelocationRef was not previously handling this case, and was instead trying to handle it as a section-relative fixup.
I think this is the right fix here, but my elf-fu is poor on some of the more exotic platforms, so I'd appreciate it if anyone with greater knowledge could verify this.
llvm-svn: 188572
same way as X86_64_GOT relocations. The 'Load' part of GOTLoad is just an
optimization hint for the linker anyway, and can be safely ignored.
This patch also fixes some minor issues with the relocations introduced while
processing an X86_64_GOT[Load]: the addend for the GOT entry should always be
zero, and the addend for the replacement relocation at the original offset
should be the same as the addend of the relocation being replaced.
I haven't come up with a good way of testing this yet, but I'm working on it.
This fixes <rdar://problem/14651564>.
llvm-svn: 188499
* ELFTypes.h contains template magic for defining types based on endianess, size, and alignment.
* ELFFile.h defines the ELFFile class which provides low level ELF specific access.
* ELFObjectFile.h contains ELFObjectFile which uses ELFFile to implement the ObjectFile interface.
llvm-svn: 188022
This patch provides basic support for powerpc64le as an LLVM target.
However, use of this target will not actually generate little-endian
code. Instead, use of the target will cause the correct little-endian
built-in defines to be generated, so that code that tests for
__LITTLE_ENDIAN__, for example, will be correctly parsed for
syntax-only testing. Code generation will otherwise be the same as
powerpc64 (big-endian), for now.
The patch leaves open the possibility of creating a little-endian
PowerPC64 back end, but there is no immediate intent to create such a
thing.
The LLVM portions of this patch simply add ppc64le coverage everywhere
that ppc64 coverage currently exists. There is nothing of any import
worth testing until such time as little-endian code generation is
implemented. In the corresponding Clang patch, there is a new test
case variant to ensure that correct built-in defines for little-endian
code are generated.
llvm-svn: 187179
Similar to ARM change r182800, dynamic linker will read bits/addends from
the original object rather than from the object that might have been patched
previously. For the purpose of relocations for MCJIT stubs on MIPS, we
internally use otherwise unused MIPS relocations.
The change also enables MCJIT unit tests for MIPS (EL/BE), and the following
two tests now pass:
- MCJITTest.return_global and
- MCJITTest.multiple_functions.
These issues have been tracked as Bug 16250.
Patch by Petar Jovanovic.
llvm-svn: 187019
According to the AArch64 ELF specification (4.6.8), it's the
assembler's responsibility to make sure the shift amount is correct in
relocated MOVZ/MOVK instructions.
This wasn't being obeyed by either the MCJIT CodeGen or RuntimeDyldELF
(which happened to work out well for JIT tests). This commit should
make us compliant in this area.
llvm-svn: 185360
In ELF (as in MachO), not all relocations point to symbols. Represent this
properly by using a symbol_iterator instead of a SymbolRef. Update llvm-readobj
ELF's dumper to handle relocatios without symbols.
llvm-svn: 183284
This was missing from r182908. I didn't noticed it at the time because the MCJIT tests were
disabled when building with cmake on ppc64 (which I fixed in r183143).
llvm-svn: 183147
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
Previously we would read-modify-write the target bits when processing
relocations for the MCJIT. This had the problem that when relocations
were processed multiple times for the same object file (as they can
be), the result is not idempotent and the values became corrupted.
The solution to this is to take any bits used in the destination from
the pristine object file as LLVM emitted it.
This should fix PR16013 and remote MCJIT on ARM ELF targets.
llvm-svn: 182800
libExecutionEngine. Move method implementations that aren't specific to
allocation out of SectionMemoryManager and into RTDyldMemoryManager.
This is in preparation for exposing RTDyldMemoryManager through the C
API.
This is a fixed version of r182407 and r182411. That first revision
broke builds because I forgot to move the conditional includes of
various POSIX headers from SectionMemoryManager into
RTDyldMemoryManager. Those includes are necessary because of how
getPointerToNamedFunction works around the glibc libc_nonshared.a thing.
The latter revision still broke things because I forgot to include
llvm/Config/config.h.
llvm-svn: 182418
libExecutionEngine. Move method implementations that aren't specific to
allocation out of SectionMemoryManager and into RTDyldMemoryManager.
This is in preparation for exposing RTDyldMemoryManager through the C
API.
This is a fixed version of r182407. That revision broke builds because I
forgot to move the conditional includes of various POSIX headers from
SectionMemoryManager into RTDyldMemoryManager. Those includes are
necessary because of how getPointerToNamedFunction works around the
glibc libc_nonshared.a thing.
llvm-svn: 182411
libExecutionEngine. Move method implementations that aren't specific to
allocation out of SectionMemoryManager and into RTDyldMemoryManager.
This is in preparation for exposing RTDyldMemoryManager through the C
API.
llvm-svn: 182407
AArch64 ELF uses .rela relocations so there's no need to actually make
use of the bits we're setting in the destination However, we should
make sure all bits are cleared properly since multiple runs of
resolveRelocations are possible and these could combine to produce
invalid results if stale versions remain in the code.
llvm-svn: 182214
This gets exception handling working on ELF and Macho (x86-64 at least).
Other than the EH frame registration, this patch also implements support
for GOT relocations which are used to locate the personality function on
MachO.
llvm-svn: 181167
This is about the simplest relocation, but surprisingly rare in actual
code.
It occurs in (for example) the MCJIT test test-ptr-reloc.ll.
llvm-svn: 181134
As with global accesses, external functions could exist anywhere in
memory. Therefore the stub must create a complete 64-bit address. This
patch implements the fragment as (roughly):
movz x16, #:abs_g3:somefunc
movk x16, #:abs_g2_nc:somefunc
movk x16, #:abs_g1_nc:somefunc
movk x16, #:abs_g0_nc:somefunc
br x16
In principle we could save 4 bytes by using a literal-load instead,
but it is unclear that would be more efficient and can only be tested
when real hardware is readily available.
This allows (for example) the MCJIT test 2003-05-07-ArgumentTest to
pass on AArch64.
llvm-svn: 181133
The large memory model (default and main viable for JIT) emits
addresses in need of relocation as
movz x0, #:abs_g3:somewhere
movk x0, #:abs_g2_nc:somewhere
movk x0, #:abs_g1_nc:somewhere
movk x0, #:abs_g0_nc:somewhere
To support this we must implement those four relocations in the
dynamic loader.
This allows (for example) the test-global.ll MCJIT test to pass on
AArch64.
llvm-svn: 181132
R_AARCH64_PCREL32 is present in even trivial .eh_frame sections and so
is required to compile any function without the "nounwind" attribute.
This change implements very basic infrastructure in the RuntimeDyldELF
file and allows (for example) the test-shift.ll MCJIT test to pass
on AArch64.
llvm-svn: 181131
Another step towards reinstating the SystemZ backend. I'll commit
the configure changes separately (TARGET_HAS_JIT etc.), then commit
a patch to enable the MCJIT tests on SystemZ.
llvm-svn: 181015
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
The implemented RuntimeDyldImpl interface is public. Everything else is private.
Since these classes are not inherited from (yet), there is no need to have
protected members.
llvm-svn: 180733
For MachO we need information that is not represented in ObjRelocationInfo.
Instead of copying the bits we think are needed from a relocation_iterator,
just pass the relocation_iterator down to the format specific functions.
No functionality change yet as we still drop the information once
processRelocationRef returns.
llvm-svn: 180711
For Mach-O there were 2 implementations for parsing object files. A
standalone llvm/Object/MachOObject.h and llvm/Object/MachO.h which
implements the generic interface in llvm/Object/ObjectFile.h.
This patch adds the missing features to MachO.h, moves macho-dump to
use MachO.h and removes ObjectFile.h.
In addition to making sure that check-all is clean, I checked that the
new version produces exactly the same output in all Mach-O files in a
llvm+clang build directory (including executables and shared
libraries).
To test the performance, I ran macho-dump over all the files in a
llvm+clang build directory again, but this time redirecting the output
to /dev/null. Both the old and new versions take about 4.6 seconds
(2.5 user) to finish.
llvm-svn: 180624
* We only ever specialize these templates with an instantiation of ELFType,
so we don't need a template template.
* Replace LLVM_ELF_COMMA with just passing the individual parameters to the
macro. This requires a second macro for when we only have ELFT, but that
is still a small win.
llvm-svn: 179726
I will remove the isBigEndianHost function once I update clang.
The ifdef logic is designed to
* not use configure/cmake to avoid breaking -arch i686 -arch ppc.
* default to little endian
* be as small as possible
It looks like sys/endian.h is the preferred header on most modern BSD systems,
but it is better to change this in a followup patch as machine/endian.h is
available on FreeBSD, OpenBSD, NetBSD and OS X.
llvm-svn: 179527
When the RuntimeDyldELF::processRelocationRef routine finds the target
symbol of a relocation in the local or global symbol table, it performs
a section-relative relocation:
Value.SectionID = lsi->second.first;
Value.Addend = lsi->second.second;
At this point, however, any Addend that might have been specified in
the original relocation record is lost. This is somewhat difficult to
trigger for relocations within the code section since they usually
do not contain non-zero Addends (when built with the default JIT code
model, in any case). However, the problem can be reliably triggered
by a relocation within the data section caused by code like:
int test[2] = { -1, 0 };
int *p = &test[1];
The initializer of "p" will need a relocation to "test + 4". On
platforms using RelA relocations this means an Addend of 4 is required.
Current code ignores this addend when processing the relocation,
resulting in incorrect execution.
Fixed by taking the Addend into account when processing relocations
to symbols found in the local or global symbol table.
Tested on x86_64-linux and powerpc64-linux.
llvm-svn: 178869
Charles Davis