`Data` now references the first byte of the fixup offset within the current fragment.
MCAssembler::layout asserts that the fixup offset is within either the
fixed-size content or the optional variable-size tail, as this is the
most the generic code can validate without knowing the target-specific
fixup size.
Many backends applyFixup assert
```
assert(Offset + Size <= F.getSize() && "Invalid fixup offset!");
```
This refactoring allows a subsequent change to move the fixed-size
content outside of MCSection::ContentStorage, fixing the
-fsanitize=pointer-overflow issue of #150846
Pull Request: https://github.com/llvm/llvm-project/pull/151724
Avoid reliance on the MCAssembler::evaluateFixup workaround that checks
MCFixupKindInfo::FKF_IsPCRel. Additionally, standardize how fixups are
appended. This helper will facilitate future fixup data structure
optimizations.
Follow-up to #141333. Relocation generation called both addReloc and
applyFixup, with the default addReloc invoking shouldForceRelocation,
resulting in three virtual calls. This approach was also inflexible, as
targets needing additional data required extending
`shouldForceRelocation` (see #73721, resolved by #141311).
This change integrates relocation handling into applyFixup, eliminating
two virtual calls. The prior default addReloc is renamed to
maybeAddReloc. Targets overriding addReloc now call their customized
addReloc implementation.
Remove the MCSubtargetInfo argument from applyFixup, introduced in
https://reviews.llvm.org/D45962 , as it's only required by ARM. Instead,
add const MCFragment & so that ARMAsmBackend can retrieve
MCSubtargetInfo via a static member function.
Additionally, remove the MCAssembler argument, which is also only
required by ARM.
Additionally, make applyReloc non-const. Its arguments now fully cover
addReloc's functionality.
This reverts the code change in commit
e87f33d9ce785668223c3bcc4e06956985cccda1 (#73721) but keeps its test.
There have been many changes to lib/MC and AsmBackend.cpp files, so this
is not a pure revert.
#73721, a workaround to generate necessary relocations in mixed
non-relax/relax code,
is no longer necessary after #140692 fixed the root issue (whether two
locations are separated by a fragment with indeterminate size due to
linker relaxation).
We will increase the use of raw relocation types and eliminate fixup
kinds that correspond to relocation types. The getFixupKindInfo
functions will return an rvalue instead. Let's update the return type
from a const reference to a value type.
Add two helper functions to simplify checks for relocation types,
replacing direct comparisons with FirstRelocationKind and
FirstLiteralRelocationKind. Note: Some targets haven't utilized
isRelocation yet.
Also, update RelaxFixupKind to use 0 as the sentinel value.
Target shouldForceRelocation checks `FirstLiteralRelocationKind` to
determine whether a relocation is forced due to the .reloc directive. We
should move the code to evaluateFixup so that many targets don't need to
override shouldForceRelocation.
https://reviews.llvm.org/D23669 inappropriately added MIPS-specific
dtprel/tprel directives to MCStreamer. In addition,
llvm-mc -filetype=null parsing these directives will crash.
This patch moves these functions to MipsTargetStreamer and fixes
-filetype=null.
gprel32 and gprel64, called by AsmPrinter, are moved to
MCTargetStreamer.
e.g.
`addiu $t2, $t3, .Lend-.Lstart-4`
used by libdragon/boot/boot_trampoline.S
To make this work, update a few places:
* AsmParser: When matching a isSImm/isUImm, consider an expression
that does not evaluate to an assemble-time constant an immediate.
* MCCodeEmitter: If this is an I-type instruction and the expression
does not evaluate to an assemble-time constant, append a
`fixup_Mips_AnyImm16`.
TODO: in MipsInstrInfo.td, more `Operand` should switch from the
default `getMachineOpValue` to `getImmOpValue` like RISCV.
* AsmBackend: If the expression does not evaluate to a constant
with assembler layout information, report "unknown relocation type"
like X86. If the result is not within [-32768,65535] (the bound gas
uses when parsing a constant integer for ADDIU)
Fix#126531
Pull Request: https://github.com/llvm/llvm-project/pull/127581
Note that llvm::support::endianness has been renamed to
llvm::endianness while becoming an enum class as opposed to an
enum. This patch replaces support::{big,little,native} with
llvm::endianness::{big,little,native}.
LLVM contains a helpful function for getting the size of a C-style
array: `llvm::array_lengthof`. This is useful prior to C++17, but not as
helpful for C++17 or later: `std::size` already has support for C-style
arrays.
Change call sites to use `std::size` instead.
Differential Revision: https://reviews.llvm.org/D133429
... to match most other common architectures which already support BFD_RELOC_*.
BFD_RELOC_NONE provides a generic way indicating a dependency between two
sections and is useful for some instrumentations which encode symbol index
information (e.g. `.cg_profile`).
This reverts commit ef8206320769ad31422a803a0d6de6077fd231d2.
- It conflicts with the existing llvm::size in STLExtras, which will now
never be called.
- Calling it without llvm:: breaks C++17 compat
On some architectures such as Arm and X86 the encoding for a nop may
change depending on the subtarget in operation at the time of
encoding. This change replaces the per module MCSubtargetInfo retained
by the targets AsmBackend in favour of passing through the local
MCSubtargetInfo in operation at the time.
On Arm using the architectural NOP instruction can have a performance
benefit on some implementations.
For Arm I've deleted the copy of the AsmBackend's MCSubtargetInfo to
limit the chances of this causing problems in the future. I've not
done this for other targets such as X86 as there is more frequent use
of the MCSubtargetInfo and it looks to be for stable properties that
we would not expect to vary per function.
This change required threading STI through MCNopsFragment and
MCBoundaryAlignFragment.
I've attempted to take into account the in tree experimental backends.
Differential Revision: https://reviews.llvm.org/D45962
R_ARM_NONE can be used to create references among sections. When
--gc-sections is used, the referenced section will be retained if the
origin section is retained.
Add a generic MCFixupKind FK_NONE as this kind of no-op relocation is
ubiquitous on ELF and COFF, and probably available on many other binary
formats. See D62014.
Reviewed By: peter.smith
Differential Revision: https://reviews.llvm.org/D61992
llvm-svn: 360980
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
R_MIPS_JALR/R_MICROMIPS_JALR can now be parsed in .s files and emitted to .o.
They are still not generated with JALR.
Differential revision: https://reviews.llvm.org/D54721
llvm-svn: 347398
When a landing pad is calculated in a program that is compiled
for micromips, it will point to an even address. Such an error will
cause a segmentation fault, as the instructions in micromips are
aligned on odd addresses. This patch sets the last bit of the offset
where a landing pad is, to 1, which will effectively be
an odd address and point to the instruction exactly.
Differential Revision: https://reviews.llvm.org/D52985
llvm-svn: 344591
Add support mips64(el)-linux-gnuabin32 triples, and set them to N32.
Debian architecture name mipsn32/mipsn32el are also added. Set
UseIntegratedAssembler for N32 if we can detect it.
Patch by YunQiang Su.
Differential revision: https://reviews.llvm.org/D51408
llvm-svn: 342416
On targets like Arm some relaxations may only be performed when certain
architectural features are available. As functions can be compiled with
differing levels of architectural support we must make a judgement on
whether we can relax based on the MCSubtargetInfo for the function. This
change passes through the MCSubtargetInfo for the function to
fixupNeedsRelaxation so that the decision on whether to relax can be made
per function. In this patch, only the ARM backend makes use of this
information. We must also pass the MCSubtargetInfo to applyFixup because
some fixups skip error checking on the assumption that relaxation has
occurred, to prevent code-generation errors applyFixup must see the same
MCSubtargetInfo as fixupNeedsRelaxation.
Differential Revision: https://reviews.llvm.org/D44928
llvm-svn: 334078
Supporting GOT and TLS related relocations by the `.reloc` directive is
useful for purpose of testing various tools like a linker, for example.
llvm-svn: 333773
Emit R_MICROMIPS_GPREL16/R_MICROMIPS_SUB/R_MICROMIPS_LO16 and
R_MICROMIPS_GPREL16/R_MICROMIPS_SUB/R_MICROMIPS_HI16 chains of
relocations for %lo(%neg(%gp_rel())) and %hi(%neg(%gp_rel()))
expressions in case of microMIPS.
Differential Revision: http://reviews.llvm.org/D47220
llvm-svn: 333409
Emit R_MICROMIPS_HIGHER / R_MICROMIPS_HIGHEST relocations for %higher()
and %highest() expressions in case of microMIPS. These relocations do
exactly the same things as R_MIPS_HIGHER / R_MIPS_HIGHEST, but for
consistency it's better to write microMIPS variants.
Differential Revision: http://reviews.llvm.org/D47219
llvm-svn: 333407
With this we gain a little flexibility in how the generic object
writer is created.
Part of PR37466.
Differential Revision: https://reviews.llvm.org/D47045
llvm-svn: 332868
To make this work I needed to add an endianness field to MCAsmBackend
so that writeNopData() implementations know which endianness to use.
Part of PR37466.
Differential Revision: https://reviews.llvm.org/D47035
llvm-svn: 332857
Summary:
I recently added a new Fixup kind to our fork of LLVM but forgot to add
it to the table in MipsAsmBackend.cpp. With this static_assert the error
would have been caught instead of zero-initializing the array entries for
the new fixups.
Reviewers: sdardis, atanasyan
Reviewed By: atanasyan
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D44895
llvm-svn: 328616
Currently it's not possible to access MCSubtargetInfo from a TgtMCAsmBackend.
D20830 threaded an MCSubtargetInfo reference through
MCAsmBackend::relaxInstruction, but this isn't the only function that would
benefit from access. This patch removes the Triple and CPUString arguments
from createMCAsmBackend and replaces them with MCSubtargetInfo.
This patch just changes the interface without making any intentional
functional changes. Once in, several cleanups are possible:
* Get rid of the awkward MCSubtargetInfo handling in ARMAsmBackend
* Support 16-bit instructions when valid in MipsAsmBackend::writeNopData
* Get rid of the CPU string parsing in X86AsmBackend and just use a SubtargetFeature for HasNopl
* Emit 16-bit nops in RISCVAsmBackend::writeNopData if the compressed instruction set extension is enabled (see D41221)
This change initially exposed PR35686, which has since been resolved in r321026.
Differential Revision: https://reviews.llvm.org/D41349
llvm-svn: 321692
functions.
This makes the ownership of the resulting MCObjectWriter clear, and allows us
to remove one instance of MCObjectStreamer's bizarre "holding ownership via
someone else's reference" trick.
llvm-svn: 315327
The N32 ABI uses RELA relocation format, do not use 3-in-1 relocation's
encoding, and uses ELFCLASS32. This change passes the `IsN32` flag
to the `MCAsmBackend` to distinguish usage of N32 ABI.
We still do not handle some cases like providing the `-target-abi=o32`
command line option with the `mips64` target triple. That's why
elf_header.s contains some "FIXME" strings. This case will be fixed in
a separate patch.
Differential revision: https://reviews.llvm.org/D37960
llvm-svn: 313873
