Previously, when loading an object file, RuntimeDyld (1) took ownership of the
ObjectFile instance (and associated MemoryBuffer), (2) potentially modified the
object in-place, and (3) returned an ObjectImage that managed ownership of the
now-modified object and provided some convenience methods. This scheme accreted
over several years as features were tacked on to RuntimeDyld, and was both
unintuitive and unsafe (See e.g. http://llvm.org/PR20722).
This patch fixes the issue by removing all ownership and in-place modification
of object files from RuntimeDyld. Existing behavior, including debugger
registration, is preserved.
Noteworthy changes include:
(1) ObjectFile instances are now passed to RuntimeDyld by const-ref.
(2) The ObjectImage and ObjectBuffer classes have been removed entirely, they
existed to model ownership within RuntimeDyld, and so are no longer needed.
(3) RuntimeDyld::loadObject now returns an instance of a new class,
RuntimeDyld::LoadedObjectInfo, which can be used to construct a modified
object suitable for registration with the debugger, following the existing
debugger registration scheme.
(4) The JITRegistrar class has been removed, and the GDBRegistrar class has been
re-written as a JITEventListener.
This should fix http://llvm.org/PR20722 .
llvm-svn: 222810
There are two methods in SectionRef that can fail:
* getName: The index into the string table can be invalid.
* getContents: The section might point to invalid contents.
Every other method will always succeed and returning and std::error_code just
complicates the code. For example, a section can have an invalid alignment,
but if we are able to get to the section structure at all and create a
SectionRef, we will always be able to read that invalid alignment.
llvm-svn: 219314
field of RelocationValueRef, rather than the 'Addend' field.
This is consistent with RuntimeDyldELF's use of RelocationValueRef, and more
consistent with the semantics of the data being stored (the offset from the
start of a section or symbol).
llvm-svn: 217328
Summary:
Introduce support::ulittleX_t::ref type to Support/Endian.h and use it in x86 JIT
to enforce correct endianness and fix unaligned accesses.
Test Plan: regression test suite
Reviewers: lhames
Subscribers: ributzka, llvm-commits
Differential Revision: http://reviews.llvm.org/D5011
llvm-svn: 216631
The expressions 'Reloc.Addend - Addend' and 'Reloc.Offset' should always be
equal in this context. The latter is prefered - we want to remove the
RelocationValueRef::Addend field in the future.
llvm-svn: 216418
Owning the buffer is somewhat inflexible. Some Binaries have sub Binaries
(like Archive) and we had to create dummy buffers just to handle that. It is
also a bad fit for IRObjectFile where the Module wants to own the buffer too.
Keeping this ownership would make supporting IR inside native objects
particularly painful.
This patch focuses in lib/Object. If something elsewhere used to own an Binary,
now it also owns a MemoryBuffer.
This patch introduces a few new types.
* MemoryBufferRef. This is just a pair of StringRefs for the data and name.
This is to MemoryBuffer as StringRef is to std::string.
* OwningBinary. A combination of Binary and a MemoryBuffer. This is needed
for convenience functions that take a filename and return both the
buffer and the Binary using that buffer.
The C api now uses OwningBinary to avoid any change in semantics. I will start
a new thread to see if we want to change it and how.
llvm-svn: 216002
Having both Triple::arm64 and Triple::aarch64 is extremely confusing, and
invites bugs where only one is checked. In reality, the only legitimate
difference between the two (arm64 usually means iOS) is also present in the OS
part of the triple and that's what should be checked.
We still parse the "arm64" triple, just canonicalise it to Triple::aarch64, so
there aren't any LLVM-side test changes.
llvm-svn: 213743
This patch enables the new ELFv2 ABI in the runtime dynamic loader.
The loader has to implement the following features:
- In the ELFv2 ABI, do not look up a function descriptor in .opd, but
instead use the local entry point when resolving a direct call.
- Update the TOC restore code to use the new TOC slot linkage area
offset.
- Create PLT stubs appropriate for the ELFv2 ABI.
Note that this patch also adds common-code changes. These are necessary
because the loader must check the newly added ELF flags: the e_flags
header bits encoding the ABI version, and the st_other symbol table
entry bits encoding the local entry point offset. There is currently
no way to access these, so I've added ObjectFile::getPlatformFlags and
SymbolRef::getOther accessors.
Reviewed by Hal Finkel.
llvm-svn: 213491
Current PPC64 RuntimeDyld code to handle TOC relocations has two
problems:
- With recent linkers, in addition to the relocations that implicitly
refer to the TOC base (R_PPC64_TOC*), you can now also use the .TOC.
magic symbol with any other relocation to refer to the TOC base
explicitly. This isn't currently used much in ELFv1 code (although
it could be), but it is essential in ELFv2 code.
- In a complex JIT environment with multiple modules, each module may
have its own .toc section, and TOC relocations in one module must
refer to *its own* TOC section. The current findPPC64TOC implementation
does not correctly implement this; in fact, it will always return the
address of the first TOC section it finds anywhere. (Note that at the
time findPPC64TOC is called, we don't even *know* which module the
relocation originally resided in, so it is not even possible to fix
this routine as-is.)
This commit fixes both problems by handling TOC relocations earlier, in
processRelocationRef. To do this, I've removed the findPPC64TOC routine
and replaced it by a new routine findPPC64TOCSection, which works
analogously to findOPDEntrySection in scanning the sections of the
ObjImage provided by its caller, processRelocationRef. This solves the
issue of finding the correct TOC section associated with the current
module.
This makes it straightforward to implement both R_PPC64_TOC relocations,
and relocations explicitly refering to the .TOC. symbol, directly in
processRelocationRef. There is now a new problem in implementing the
R_PPC64_TOC16* relocations, because those can now in theory involve
*three* different sections: the relocation may be applied in section A,
refer explicitly to a symbol in section B, and refer implicitly to the
TOC section C. The final processing of the relocation thus may only
happen after all three of these sections have been assigned final
addresses. There is currently no obvious means to implement this in
its general form with the common-code RuntimeDyld infrastructure.
Fortunately, ppc64 code usually makes no use of this most general form;
in fact, TOC16 relocations are only ever generated by LLVM for symbols
residing themselves in the TOC, which means "section B" == "section C"
in the above terminology. This special case can easily be handled with
the current infrastructure, and that is what this patch does.
[ Unhandled cases result in an explicit error, unlike the current code
which silently returns the wrong TOC base address ... ]
This patch makes the JIT work on both BE and LE (ELFv2 requires
additional patches, of course), and allowed me to successfully run
complex JIT scenarios (via mesa/llvmpipe).
Reviewed by Hal Finkel.
llvm-svn: 211885
When RuntimeDyldELF creates stub functions, it needs to install
relocations that will resolve to the final address of the target
routine. Since those are 16-bit relocs, they need to be applied to the
least-significant halfword of the instruction. On big-endian ppc64,
this means that addresses have to be adjusted by 2, which is what the
code currently does.
However, on a little-endian system, the address must *not* be adjusted;
the least-significant halfword is the first one. This patch updates the
RuntimeDyldELF code to take the target byte order into account.
llvm-svn: 211384
This adds support for several missing PPC64 relocations in the
straight-forward manner to RuntimeDyldELF.cpp.
Note that this actually fixes a failure of a large-model test case on
PowerPC, allowing the XFAIL to be removed.
llvm-svn: 211382
SECTDIFF relocations on 32-bit x86.
This fixes several of the MCJIT regression test failures that show up on 32-bit
builds.
<rdar://problem/16886294>
llvm-svn: 208635
A bunch of switch cases were missing, not just for ARM64 but also for
AArch64_BE. I've fixed all those, but there's zero testing as
ExecutionEngine tests are disabled when crosscompiling and I don't
have a native platform available to test on.
llvm-svn: 207626
MSVC 2013 provides std::make_unique, which it finds with ADL when one of
the parameters is std::unique_ptr, leading to an ambiguous overload.
llvm-svn: 207597
This starts in MCJIT::getSymbolAddress where the
unique_ptr<object::Binary> is release()d and (after a cast) passed to a
single caller, MCJIT::addObjectFile.
addObjectFile calls RuntimeDyld::loadObject.
RuntimeDld::loadObject calls RuntimeDyldELF::createObjectFromFile
And the pointer is never owned at this point. I say this point, because
the alternative codepath, RuntimeDyldMachO::createObjectFile certainly
does take ownership, so this seemed like a good hint that this was a/the
right place to take ownership.
llvm-svn: 207580
Some targets require more than one relocation entry to perform a relocation.
This change allows processRelocationRef to process more than one relocation
entry at a time by passing the relocation iterator itself instead of just
the relocation entry.
Related to <rdar://problem/16199095>
llvm-svn: 204439
When resolving a function call to an external routine, the dynamic
loader must patch the "nop" after the branch instruction to a load
that restores the TOC register.
Current code does that, but only with the *first* instance of a call
to any particular external routine, i.e. at the point where it also
allocates the call stub. With subsequent calls to the same routine,
current code neglects to patch in the TOC restore code. This is a
bug, and leads to corrupt TOC pointers in those cases.
Fixed by patching in restore code every time.
llvm-svn: 203580
This compiles with no changes to clang/lld/lldb with MSVC and includes
overloads to various functions which are used by those projects and llvm
which have OwningPtr's as parameters. This should allow out of tree
projects some time to move. There are also no changes to libs/Target,
which should help out of tree targets have time to move, if necessary.
llvm-svn: 203083
findOrEmitSection).
Vaidas Gasiunas's patch, r201259, fixed one instance where we were always
allocating sections as text. This patch fixes the remaining buggy call sites.
No test case: This isn't breaking anything that I know of, it's just
inconsistent.
<rdar://problem/15943542>
llvm-svn: 201605
None of the object file formats reported error on iterator increment. In
retrospect, that is not too surprising: no object format stores symbols or
sections in a linked list or other structure that requires chasing pointers.
As a consequence, all error checking can be done on begin() and end().
This reduces the text segment of bin/llvm-readobj in my machine from 521233 to
518526 bytes.
llvm-svn: 200442
After all hard work to implement the EHABI and with the test-suite
passing, it's time to turn it on by default and allow users to
disable it as a work-around while we fix the eventual bugs that show
up.
This commit also remove the -arm-enable-ehabi-descriptors, since we
want the tables to be printed every time the EHABI is turned on
for non-Darwin ARM targets.
Although MCJIT EHABI is not working yet (needs linking with the right
libraries), this commit also fixes some relocations on MCJIT regarding
the EH tables/lib calls, and update some tests to avoid using EH tables
when none are needed.
The EH tests in the test-suite that were previously disabled on ARM
now pass with these changes, so a follow-up commit on the test-suite
will re-enable them.
llvm-svn: 200388
I believe the bot failures on linux systems were due to overestimating the
alignment of object-files within archives, which are only guaranteed to be
two-byte aligned. I have reduced the alignment in
RuntimeDyldELF::createObjectImageFromFile accordingly.
llvm-svn: 198737
Instead of processing relocation for branch to stubs right away, emit a
modified relocation and add it to queue to be resolved later when final load
address is known.
This resolves seven MIPS MCJIT issues that were caused by missing relocation
fixups at the end.
llvm-svn: 195157
It's useful for the memory managers that are allocating a section to know what the name of the section is.
At a minimum, this is useful for low-level debugging - it's customary for JITs to be able to tell you what
memory they allocated, and as part of any such dump, they should be able to tell you some meta-data about
what each allocation is for. This allows clients that supply their own memory managers to do this.
Additionally, we also envision the SectionName being useful for passing meta-data from within LLVM to an LLVM
client.
This changes both the C and C++ APIs, and all of the clients of those APIs within LLVM. I'm assuming that
it's safe to change the C++ API because that API is allowed to change. I'm assuming that it's safe to change
the C API because we haven't shipped the API in a release yet (LLVM 3.3 doesn't include the MCJIT memory
management C API).
llvm-svn: 191804
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
* 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
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
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
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
* 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
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
This simplifies the usage and implementation of ELFObjectFile by using ELFType
to replace:
<endianness target_endianness, std::size_t max_alignment, bool is64Bits>
This does complicate the base ELF types as they must now use template template
parameters to partially specialize for the 32 and 64bit cases. However these
are only defined once.
llvm-svn: 172515
This patch adjust the r171506 to make all DWARF enconding pc-relative
for PPC64. It also adds the R_PPC64_REL32 relocation handling in MCJIT
(since the eh_frame will not generate PIC-relative relocation) and also
adds the emission of stubs created by the TTypeEncoding.
llvm-svn: 171979
This patch fixes the PPC eh_frame definitions for the personality and
frame unwinding for PIC objects. It makes PIC build correctly creates
relative relocations in the '.rela.eh_frame' segments and thus avoiding
a text relocation that generates a DT_TEXTREL segments in link phase.
llvm-svn: 171506
This small change adds support for that. It will make all MCJIT tests pass
in make-check on BigEndian platforms.
Patch by Petar Jovanovic.
llvm-svn: 169178
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.
Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]
llvm-svn: 169131
all symbols during object loading, not just global ones.
This fixes JIT execution of code using llvm.global_ctors with internal
linkage constructors.
llvm-svn: 168148
Some ELF relocations require adding the a value to the original contents of the object buffer at the specified location. In order to properly handle multiple applications of a relocation, the RuntimeDyld code should be grabbing the original value from the object buffer and writing a new value into the loaded section buffer. This patch changes the parameters passed to resolveRelocations to accommodate this need.
llvm-svn: 167304
No new tests are added.
All tests in ExecutionEngine/MCJIT that have been failing pass after this patch
is applied (when "make check" is done on a mips board).
Patch by Petar Jovanovic.
llvm-svn: 162135
- Improved parameter names for clarity
- Added comments
- emitCommonSymbols should return void because its return value is not being
used anywhere
- Attempt to reduce the usage of the RelocationValueRef type. Restricts it
for a single goal and may serve as a step for eventual removal.
llvm-svn: 155908
- There's no point having a different type for the local and global symbol
tables.
- Renamed SymbolTable to GlobalSymbolTable to clarify the intention
- Improved const correctness where relevant
llvm-svn: 155898
- Add comments
- Change field names to be more reasonable
- Fix indentation and naming to conform to coding conventions
- Remove unnecessary includes / replace them by forward declatations
llvm-svn: 155815
the MCJIT execution engine.
The GDB JIT debugging integration support works by registering a loaded
object image with a pre-defined function that GDB will monitor if GDB
is attached. GDB integration support is implemented for ELF only at this
time. This integration requires GDB version 7.0 or newer.
Patch by Andy Kaylor!
llvm-svn: 154868
of zero-initialized sections, virtual sections and common symbols
and preventing the loading of sections which are not required for
execution such as debug information.
Patch by Andy Kaylor!
llvm-svn: 154610
1. The main works will made in the RuntimeDyLdImpl with uses the ObjectFile class. RuntimeDyLdMachO and RuntimeDyLdELF now only parses relocations and resolve it. This is allows to make improvements of the RuntimeDyLd more easily. In addition the support for COFF can be easily added.
2. Added ARM relocations to RuntimeDyLdELF.
3. Added support for stub functions for the ARM, allowing to do a long branch.
4. Added support for external functions that are not loaded from the object files, but can be loaded from external libraries. Now MCJIT can correctly execute the code containing the printf, putc, and etc.
5. The sections emitted instead functions, thanks Jim Grosbach. MemoryManager.startFunctionBody() and MemoryManager.endFunctionBody() have been removed.
6. MCJITMemoryManager.allocateDataSection() and MCJITMemoryManager. allocateCodeSection() used JMM->allocateSpace() instead of JMM->allocateCodeSection() and JMM->allocateDataSection(), because I got an error: "Cannot allocate an allocated block!" with object file contains more than one code or data sections.
llvm-svn: 153754
Aaron Ballman