changes:
- BLX: The Arm architecture versions that support the branch and link
instruction (BLX), can rewrite BLs in place when a state change from Arm<->Thumb
is required. Armv4T does not have BLX and so needs thunks for state changes.
- v4T Thumb long branches needed their own thunk. We could have used the v6M
implementation, but v6M doesn't have Arm state and must resolve to rather
inefficient stack reshuffling. We also can't reuse v7 thumb thunks as they use
MOVV/MOVT, which wasn't available yet for v4T.
- Remove the `lack of BLX' warning. LLVM only supports Arm Architecture versions
upwards of v4, which we now all support in LLD.
- renamed existing thunks to better reflect their use:
ARMV5ABSLongThunk -> ARMV5LongLdrPcThunk,
ARMV5PILongThunk -> ARMV4PILongThunk
- removed isCompatibleWith method from ARMV5ABSLongThunk and ARMV5PILongThunk,
as they were identical to the ARMThunk parent class implementation.
Support for (efficient) position independent thunks for v4T will be added in a
follow-up patch, including possible related thunk renaming and code comment
cleanup.
Reviewed By: MaskRay, peter.smith
Differential Revision: https://reviews.llvm.org/D139888
Currently we take the first SHT_RISCV_ATTRIBUTES (.riscv.attributes) as the
output. If we link an object without an extension with an object with the
extension, the output Tag_RISCV_arch may not contain the extension and some
tools like objdump -d will not decode the related instructions.
This patch implements
Tag_RISCV_stack_align/Tag_RISCV_arch/Tag_RISCV_unaligned_access merge as
specified by
https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/master/riscv-elf.adoc#attributes
For the deprecated Tag_RISCV_priv_spec{,_minor,_revision}, dump the attribute to
the output iff all input agree on the value. This is different from GNU ld but
our simple approach should be ok for deprecated tags.
`RISCVAttributeParser::handler` currently warns about unknown tags. This
behavior is retained. In GNU ld arm, tags >= 64 (mod 128) are ignored with a
warning. If RISC-V ever wants to do something similar
(https://github.com/riscv-non-isa/riscv-elf-psabi-doc/issues/352), consider
documenting it in the psABI and changing RISCVAttributeParser.
Like GNU ld, zero value integer attributes and empty string attributes are not
dumped to the output.
Reviewed By: asb, kito-cheng
Differential Revision: https://reviews.llvm.org/D138550
Allowing incorrect version scripts is not a helpful default. Flip that
to help users find their bugs at build time rather than at run time.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D135402
When -fgpu-rdc is used for linking relocatable objects, clang driver launches
clang-offload-bundler to extract a device relocatable object from each input
relocatable object file and passes the extracted files to lld. The input relocatable
object file could either come from HIP program or C++ program. The relocatable
object file from C++ program does not contain device relocatable objects, therefore
clang-offload-bundler extracts an empty file and passes it to lld. lld treates
empty file as linker script. When there is no object input file to lld, lld
will emit error:
target emulation unknown: -m or at least one .o file required
This patch adds "elf64_amdgpu" to lld so that lld always know the target
no matter whether there are object input files or not.
Reviewed by: Artem Belevich, Fangrui Song
Differential Revision: https://reviews.llvm.org/D138221
Follows up on commit cd5d5ce235 by
additionally ignoring relative paths ending in "lto-wrapper.exe" as
can be the case for GCC cross-compiled for Windows.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D138065
Like D134013, but for COFF and Mach-O.
Also expand the ELF test a bit. I at first didn't realize that `getValue()` for
`-mllvm -foo=bar` would return `-foo=bar` instead of just `bar`, and so
I wrote the test to check if we indeed get this wrong. We don't, but
having the test for it seems nice, so I'm including it.
Differential Revision: https://reviews.llvm.org/D137971
Allowing incorrect version scripts is not a helpful default. Flip that
to help users find their bugs at build time rather than at run time.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D135402
Mach-O ld64 supports -w to suppress warnings. GNU ld 2.40 will support the
option as well (https://sourceware.org/bugzilla/show_bug.cgi?id=29654).
This feature has some small value. E.g. when analyzing a large executable with
relocation overflow issues, we may use --noinhibit-exec --emit-relocs to get an
output file with static relocations despite relocation overflow issues. -w can
significantly improve the link time as printing the massive warnings is slow.
Reviewed By: peter.smith
Differential Revision: https://reviews.llvm.org/D136569
A reference to __real_foo should trigger archive extraction of the input file that defines foo, otherwise a link using --wrap=foo might fail to link with an undefined reference to foo.
This matches bfd linker behaviour.
Differential Revision: https://reviews.llvm.org/D135897
This reverts commit 096f93e73d.
Revert "[Libomptarget] Make the plugins ingore undefined exported symbols"
This reverts commit 3f62314c23.
Revert "[LLD] Enable --no-undefined-version by default."
This reverts commit 7ec8b0d162.
Three commits are reverted because of the current omp build fail
with GNU ld. See discussion here: https://reviews.llvm.org/rG096f93e73dc3
Allowing incorrect version scripts is not a helpful default. Flip that
to help users find their bugs at build time rather than at run time.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D135402
Add LLVM_LIBRARY_VISIBILITY to remove unneeded GOT and unique_ptr
indirection. We can move other global variables into ctx without
indirection concern. In the long term we may consider passing Ctx
as a parameter to various functions and eliminate global state as
much as possible and then remove `Ctx::reset`.
`config` has 1000+ uses so we try to avoid changing `config->foo`. Define a
wrapper with LLVM_LIBRARY_VISIBILITY to remove unneeded GOT and unique_ptr
indirection.
My x86-64 lld executable is 11+KiB smaller.
Symbol::replace intends to overwrite a few fields (mostly Elf{32,64}_Sym
fields), but the implementation copies all fields then restores some old fields.
This is error-prone and wasteful. Add Symbol::overwrite to copy just the
needed fields and add other overwrite member functions to copy the extra
fields.
They may modify thinlto optimization.
This patch only extends support for `-mllvm`. There is another way to
pass llvm flags, `-plugin-opt`, but its processing is different and will
be provided in a subsequent patch.
Differential Revision: https://reviews.llvm.org/D134013
`clang -gz=zstd a.o` passes this option to the linker. This option compresses output
debug sections with zstd and sets ch_type to ELFCOMPRESS_ZSTD. As of today, very
few DWARF consumers recognize ELFCOMPRESS_ZSTD.
Use the llvm::zstd::compress API with level llvm::zstd::DefaultCompression (5),
which we may tune after we have more experience with zstd output.
zstd has built-in parallel compression support (so we don't need to do D117853
for zlib), which is not leveraged yet.
Reviewed By: peter.smith
Differential Revision: https://reviews.llvm.org/D133548
This change renames this method match its original name and the name
used in the wasm linker.
Back in d8f8abbd4a the ELF SymbolTable
method `getSymbols()` was replaced with `forEachSymbol`.
Then in a2fc964417 `forEachSymbol` was
replaced with a `llvm::iterator_range`.
Then in e9262edf0d we came full circle
and the `llvm::iterator_range` was replaced with a `symbols()` accessor
that was identical the original `getSymbols()`.
`getSymbols` also matches the name used elsewhere in the ELF linker as
well as in both COFF and wasm backend (e.g. `InputFiles.h` and
`SyntheticSections.h`)
Differential Revision: https://reviews.llvm.org/D130787
This was recently introduced in GNU linkers and it makes sense for
ld.lld to have the same support. This implementation omits checking if
the input string is valid json to reduce size bloat.
Differential Revision: https://reviews.llvm.org/D131439
This implements the last step of
https://discourse.llvm.org/t/parallel-input-file-parsing/60164 for the ELF port.
For an ELF object file, we previously did: parse, (parallel) initializeLocalSymbols, (parallel) postParseObjectFile.
Now we do: parse, (parallel) initSectionsAndLocalSyms, (parallel) postParseObjectFile.
initSectionsAndLocalSyms does most of input section initialization.
The sequential `parse` does SHT_ARM_ATTRIBUTES/SHT_RISCV_ATTRIBUTES/SHT_GROUP initialization for now.
Performance linking some programs with --threads=8 (glibc 2.33 malloc and mimalloc):
* clang: 1.05x as fast with glibc malloc, 1.03x as fast with mimalloc
* chrome: 1.04x as fast with glibc malloc, 1.03x as fast with mimalloc
* internal search program: 1.08x as fast with glibc malloc, 1.05x as fast with mimalloc
Reviewed By: peter.smith
Differential Revision: https://reviews.llvm.org/D130810
I went over the output of the following mess of a command:
`(ulimit -m 2000000; ulimit -v 2000000; git ls-files -z | parallel --xargs -0 cat | aspell list --mode=none --ignore-case | grep -E '^[A-Za-z][a-z]*$' | sort | uniq -c | sort -n | grep -vE '.{25}' | aspell pipe -W3 | grep : | cut -d' ' -f2 | less)`
and proceeded to spend a few days looking at it to find probable typos
and fixed a few hundred of them in all of the llvm project (note, the
ones I found are not anywhere near all of them, but it seems like a
good start).
Differential Revision: https://reviews.llvm.org/D130982
inputSections temporarily contains EhInputSection objects mainly for
combineEhSections. Place EhInputSection objects into a new vector
ehInputSections instead of inputSections.
* Refactor compression namespaces across the project, making way for a possible
introduction of alternatives to zlib compression.
Changes are as follows:
* Relocate the `llvm::zlib` namespace to `llvm::compression::zlib`.
Reviewed By: MaskRay, leonardchan, phosek
Differential Revision: https://reviews.llvm.org/D128953
Allows specific “temps” to be saved, instead of the current all-or-nothing nature of --save-temps. Multiple of these “temps” can be saved by specifying the argument multiple times.
Differential Revision: https://reviews.llvm.org/D127778
`--time-trace=foo` has the same behavior as `--time-trace --time-trace-file=<file>`
had previously.
Also, for mac, make --time-trace-granularity *not* imply --time-trace, to match
behavior of the ELF port.
Differential Revision: https://reviews.llvm.org/D128451
