Assemblers change certain relocations referencing a local symbol to
reference the section symbol instead. This conversion is disabled for
many conditions (`shouldRelocateWithSymbol`), e.g. TLS symbol, for most
targets (including AArch32, x86, PowerPC, and RISC-V) GOT-generating
relocations.
However, AArch64 encodes the GOT-generating intent in MCValue::RefKind
instead of MCSymbolRef::Kind (see commit
0999cbd0b9ed8aa893cce10d681dec6d54b200ad (2014)), therefore not affected
by the code `case MCSymbolRefExpr::VK_GOT:`. As GNU ld and ld.lld
create GOT entries based on the symbol, ignoring addend, the two ldr
instructions will share the same GOT entry, which is not expected:
```
ldr x1, [x1, :got_lo12:x] // converted to .data+0
ldr x1, [x1, :got_lo12:y] // converted to .data+4
.data
// .globl x, y would suppress STT_SECTION conversion
x:
.zero 4
y:
.long 42
```
This patch changes AArch64 to suppress local symbol to STT_SECTION
conversion for GOT relocations, matching most other targets. x and y
will use different GOT entries, which IMO is the most sensable behavior.
With this change, the ABI decision on https://github.com/ARM-software/abi-aa/issues/217
will only affect relocations explicitly referencing STT_SECTION symbols, e.g.
```
ldr x1, [x1, :got_lo12:(.data+0)]
ldr x1, [x1, :got_lo12:(.data+4)]
// I consider this unreasonable uses
```
IMO all reasonable use cases are unaffected.
Link: https://github.com/llvm/llvm-project/issues/63418
GNU assembler PR: https://sourceware.org/bugzilla/show_bug.cgi?id=30788
Reviewed By: peter.smith
Differential Revision: https://reviews.llvm.org/D158577
... 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`).
MIPS 64-bit ABI does not provide special PC-relative relocation like
R_MIPS_PC32 in 32-bit case. But we can use a "chain of relocation"
defined by N64 ABIs. In that case one relocation record might contain up
to three relocations which applied sequentially. Width of a final relocation
mask applied to the result of relocation depends on the last relocation
in the chain. In case of 64-bit PC-relative relocation we need the following
chain: `R_MIPS_PC32 | R_MIPS_64`. The first relocation calculates an
offset, but does not truncate the result. The second relocation just
apply calculated result as a 64-bit value.
The 64-bit PC-relative relocation might be useful in generation of
`.eh_frame` sections to escape passing `-Wl,-z,notext` flags to linker.
Differential Revision: https://reviews.llvm.org/D80390
MCELFObjectWriter::setRType## methods are always used altogether to
build complete MIPS N64 ABI "chain" of relocations. Using single
function for this task makes code less verbose.
Prefer `MCFixupKind` where possible and add getTargetKind() to
convert to `unsigned` when needed rather than scattering cast
operators around the place.
Differential Revision: https://reviews.llvm.org/D59890
llvm-svn: 369720
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
llvm-svn: 369013
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
The following code requests 64-bit PC-relative relocations unsupported
by MIPS ABI. Now it triggers an assertion. It's better to show an error
message.
```
foo:
.quad bar - foo
```
llvm-svn: 350152
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
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
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.
In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.
Differential Revision: https://reviews.llvm.org/D43624
llvm-svn: 332240
Summary:
r327219 added wrappers to std::sort which randomly shuffle the container before sorting.
This will help in uncovering non-determinism caused due to undefined sorting
order of objects having the same key.
To make use of that infrastructure we need to invoke llvm::sort instead of std::sort.
Note: This patch is one of a series of patches to replace *all* std::sort to llvm::sort.
Refer the comments section in D44363 for a list of all the required patches.
Reviewers: sdardis, RKSimon, dsanders, atanasyan
Reviewed By: atanasyan
Subscribers: atanasyan, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D44869
llvm-svn: 328815
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
ELFObjectWriter's constructor.
Fixes the same ownership issue for ELF that r315245 did for MachO:
ELFObjectWriter takes ownership of its MCELFObjectTargetWriter, so we want to
pass this through to the constructor via a unique_ptr, rather than a raw ptr.
llvm-svn: 315254
Now we pass the 'Is64_' flag to the MCELFObjectTargetWriter ctor iif
when we make deal with N64 ABI. So it is redundant to pass additional
'IsN64' flag.
llvm-svn: 313878
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
This change converts the `MipsAsmBackend` constructor to the "standard"
form. It makes possible to use `RegisterMCAsmBackend` for the backends
registrations. Now we pass `Triple` instance to the `MipsAsmBackend`
ctor and deduce all required options like endianness and bitness from
the triple. We still need to implement explicit ABI checking for
providing correct options to backends.
Differential revision: https://reviews.llvm.org/D37519
llvm-svn: 312720
This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.
Differential Revision: https://reviews.llvm.org/D33843
llvm-svn: 304864
In case of microMIPS mode %gottprel operator should emit microMIPS
relocation R_MICROMIPS_TLS_GOTTPREL, not R_MIPS_TLS_GOTTPREL.
Differential Revision: http://reviews.llvm.org/D32617
llvm-svn: 301763
This patch makes one change to GOT handling and two changes to N64's
relocation model handling. Furthermore, the jumptable encodings have
been corrected for static N64.
Big GOT handling is now done via a new SDNode MipsGotHi - this node is
unconditionally lowered to an lui instruction.
The first change to N64's relocation handling is the lifting of the
restriction that N64 always uses PIC. Now it is possible to target static
environments.
The second change adds support for 64 bit symbols and enables them by
default. Previously N64 had patterns for sym32 mode only. In this mode all
symbols are assumed to have 32 bit addresses. sym32 mode support
is selectable with attribute 'sym32'. A follow on patch for clang will
add the necessary frontend parameter.
This partially resolves PR/23485.
Thanks to Brooks Davis for reporting the issue!
This version corrects a "Conditional jump or move depends on uninitialised
value(s)" error detected by valgrind present in the original commit.
Reviewers: dsanders, seanbruno, zoran.jovanovic, vkalintiris
Differential Revision: https://reviews.llvm.org/D23652
llvm-svn: 293279
This patch makes one change to GOT handling and two changes to N64's
relocation model handling. Furthermore, the jumptable encodings have
been corrected for static N64.
Big GOT handling is now done via a new SDNode MipsGotHi - this node is
unconditionally lowered to an lui instruction.
The first change to N64's relocation handling is the lifting of the
restriction that N64 always uses PIC. Now it is possible to target static
environments.
The second change adds support for 64 bit symbols and enables them by
default. Previously N64 had patterns for sym32 mode only. In this mode all
symbols are assumed to have 32 bit addresses. sym32 mode support
is selectable with attribute 'sym32'. A follow on patch for clang will
add the necessary frontend parameter.
This partially resolves PR/23485.
Thanks to Brooks Davis for reporting the issue!
Reviewers: dsanders, seanbruno, zoran.jovanovic, vkalintiris
Differential Revision: https://reviews.llvm.org/D23652
llvm-svn: 293164
Doing so changes the evaluation order for relocation composition.
Patch By: Daniel Sanders
Reviewers: vkalintiris, atanasyan
Differential Revision: https://reviews.llvm.org/D26401
llvm-svn: 288666
Assembler directives .dtprelword, .dtpreldword, .tprelword, and
.tpreldword generates relocations R_MIPS_TLS_DTPREL32, R_MIPS_TLS_DTPREL64,
R_MIPS_TLS_TPREL32, and R_MIPS_TLS_TPREL64 respectively.
The main motivation for this patch is to be able to write test cases
for checking correctness of the LLD linker's behaviour.
Differential Revision: https://reviews.llvm.org/D23669
llvm-svn: 279439
This is a mechanical change of comments in switches like fallthrough,
fall-through, or fall-thru to use the LLVM_FALLTHROUGH macro instead.
llvm-svn: 278902
Summary:
They are now lexed as a single token on targets where
MCAsmInfo::HasMipsExpressions is true and then parsed in a similar way to
the '~' operator as part of MCExpr::parseExpression.
As a result:
* expressions and immediates no longer have different parsing rules. The
difference is now solely down to whether evaluateAsAbsolute() succeeds.
* %hi(%neg(%gp_rel(x))) are no longer parsed as a single operator and
decomposed into the three MipsMCExpr nodes. They are parsed directly as
three MipsMCExpr nodes.
* parseMemOperand no longer needs to eat all the surrounding parenthesis
to get at the outermost operator to make this work
* %hi(%neg(%gp_rel(x))) and %lo(%neg(%gp_rel(x))) are no longer the only
3-in-1 relocs that parse for N64. They're still the only combinations that
are permitted in relocatable expressions though. Fixing that should be a
later patch.
* We no longer need to list all the tokens that can occur as the first token of
an expression or immediate.
test/MC/Mips/expr1.s:
This change also prevents the incorrect lowering of %lo(2*4)+foo to
%lo(8+foo) which is not an equivalent expression (the difference is
whether foo is truncated to 16-bit or not) and the test has been
updated to account for the macro expansion the correct expression requires.
Reviewers: sdardis
Subscribers: dsanders, sdardis, llvm-commits
Differential Revision: https://reviews.llvm.org/D23110
llvm-svn: 277988
Summary:
The failure r269410 worked around turned out to be caused by an incorrect
evaluation of R_MICROMIPS_GOT16 which then caused the GOT entries to be
incorrect.
This patch fixes the evaluation and reverts r269410.
Reviewers: sdardis, vkalintiris, rafael
Subscribers: rafael, dsanders, sdardis, llvm-commits
Differential Revision: http://reviews.llvm.org/D20242
llvm-svn: 269641
It's not entirely clear why R_MICROMIPS_(GOT|HI16|LO16) are evaluated
incorrectly in a small number of the LNT tests at this point. However, it's not
related to the STO_MIPS_MICROMIPS issue.
At this point all the microMIPS-related changes of r268900 have been reverted.
llvm-svn: 269410
As explained in r269196, microMIPS has a special case that is not correctly
implemented in LLVM. If we have a symbol 'foo' which is equivalent to
'.text+0x10'. The value of an R_MICROMIPS_LO16 relocation using 'foo' is
'foo+0x11' and not 'foo+0x10'. The in-place addend should therefore be 0x11.
This commit reverts a little more of the effect of r268900 by keeping the
symbol when the STO_MIPS_MICROMIPS flag is set for R_MIPS_GPREL32 relocations.
This fixes SingleSource/UnitTests/2003-08-11-VaListArg, and
SingleSource/UnitTests/2003-05-07-VarArgs for microMIPS.
I believe there are additional relocations that have the same issue (e.g.
R_MIPS_64, and R_MIPS_GPREL16) but for now I'm focusing on restoring our
internal buildbots back to the green state we had in r268899.
llvm-svn: 269294
Summary:
This eliminates the default case for N64 that was left out of r269047.
The change to R_MIPS_SUB is needed in this patch to make this testable since
%lo(%neg(%gp_rel(foo))) and %hi(%neg(%gp_rel(foo))) remain the only ways to get
a compound relocation from the assembler.
Reviewers: sdardis, rafael
Subscribers: dsanders, llvm-commits, sdardis
Differential Revision: http://reviews.llvm.org/D20097
llvm-svn: 269280
microMIPS has a special case that is not correctly implemented in LLVM. If we
have a symbol 'foo' which is equivalent to '.text+0x10'. The value of an
R_MICROMIPS_LO16 relocation using 'foo' is 'foo+0x11' and not 'foo+0x10'. The
in-place addend should therefore be 0x11.
Work around this by partially reverting the effect of r268900 by keeping the
symbol when the STO_MIPS_MICROMIPS flag is set. This fixes
SingleSource/Regression/C/PR640 for microMIPS.
llvm-svn: 269196
Following post-commit comments on r268900 from Rafael Espindola:
The missing relocations are now explicitly listed in the switch statement with
appropriate FIXME comments and the default path is now unreachable. The
temporary exception to this is that compound relocations for N64 still have a
default path that returns true. This is because fixing that case ought to be a
separate patch.
Also make R_MIPS_NONE return false since it has no effect on the section data.
llvm-svn: 269047
Summary:
In theory, care must be taken to ensure that pairs of R_MIPS_(GOT|HI|LO)16
make the same decision on both relocs in the reloc pair but in practice
this isn't as hard as it sounds and only limits the complexity of the
predicate used. We handle all three with the same code to ensure their
decisions always agree with each other.
Reviewers: sdardis
Subscribers: rafael, dsanders, sdardis, llvm-commits
Differential Revision: http://reviews.llvm.org/D19016
llvm-svn: 268900
