Commit Graph

1035 Commits

Author SHA1 Message Date
Brett Werling cf4f35b788 [ELF] Handle GCC collect2 -plugin-opt= on Windows
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
2022-11-16 09:58:50 -08:00
Nico Weber 67d311a5fd [COFF, Mach-O] Include -mllvm options in thinlto cache key
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
2022-11-14 15:18:09 -05:00
Jon Chesterfield b1fdeeec1a Revert "[LLD] Enable --no-undefined-version by default."
This reverts commit eedbe44b87.
2022-11-09 16:17:33 +00:00
Dan Albert eedbe44b87 [LLD] Enable --no-undefined-version by default.
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
2022-11-07 22:15:28 +00:00
Fangrui Song 26fcee601f [ELF] Add --no-warnings/-w
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
2022-10-24 10:54:09 -07:00
Ben Dunbobbin 13816e0358 [LLD][ELF] --wrap: __real_foo references should trigger archive extraction for foo
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
2022-10-18 12:53:06 +01:00
Fangrui Song 14f996dca8 [ELF] Move inputSections/ehInputSections into Ctx. NFC 2022-10-16 00:49:48 -07:00
Slava Zakharin 88da0de14f Revert "[Libomp] Do not error on undefined version script symbols"
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
2022-10-13 14:12:07 -07:00
Dan Albert 7ec8b0d162 [LLD] Enable --no-undefined-version by default.
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
2022-10-12 12:29:38 -07:00
Fangrui Song 9f9bab19e3 [ELF] Replace some config->ekind with file->ekind. NFC 2022-10-02 21:27:41 -07:00
Fangrui Song d9dbf9e30a [ELF] Move init from ELFFileBase constructor to a separate function. NFC 2022-10-02 21:10:28 -07:00
Fangrui Song c171250e38 [ELF] Simplify addFile. NFC 2022-10-02 19:49:17 -07:00
Fangrui Song f596d82385 [ELF] Move driver into ctx and remove indirection. NFC
This removes one global variable and removes GOT and unique_ptr indirection.
2022-10-01 15:12:50 -07:00
Fangrui Song 9c626d4a0d [ELF] Remove symtab indirection. NFC
Add LLVM_LIBRARY_VISIBILITY to remove unneeded GOT and unique_ptr indirection.
2022-10-01 14:46:49 -07:00
Fangrui Song 34fa860048 [ELF] Remove ctx indirection. NFC
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`.
2022-10-01 12:06:33 -07:00
Fangrui Song a623a4c8b4 [ELF] Remove elf::config indirection. NFC
`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.
2022-10-01 11:39:45 -07:00
Fangrui Song e3ecc6a912 [ELF] Make symAux[0] a sentinel
And default auxIdx to 0.
2022-09-29 00:50:19 -07:00
Fangrui Song 9e6840ccba [ELF] Remove resolve => resolve{Defined,Common,Shared,Lazy,Undefined} indirection. NFC 2022-09-28 20:01:41 -07:00
Fangrui Song 7a58dd1046 [ELF] Refactor Symbol initialization and overwriting
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.
2022-09-28 13:11:31 -07:00
Mircea Trofin c625c17b88 [lld][thinlto] Include -mllvm options in the thinlto cache key
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
2022-09-19 12:04:17 -07:00
Fangrui Song 12607f57da [ELF] Cache compute_thread_count. NFC 2022-09-12 19:09:08 -07:00
Fangrui Song 449f2ca146 [ELF] Add --compress-debug-sections=zstd
`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
2022-09-09 10:30:18 -07:00
Sam Clegg 2cd4cd9a32 [lld][ELF] Rename SymbolTable::symbols() to SymbolTable::getSymbols(). NFC
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
2022-08-19 14:56:08 -07:00
Alex Brachet dbd04b853b [ELF] Support --package-metadata
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
2022-08-08 21:31:58 +00:00
Fangrui Song e89d6d2ac5 [ELF] Keep only getTarget() call. NFC
The place from D61712 seems unneeded now. We can just use the place added by
D62609 (support AArch64 BTI/PAC).
2022-08-05 18:20:23 -07:00
Fangrui Song 2515cb80cd [ELF] Parallelize input section initialization
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
2022-08-04 11:47:52 -07:00
Gabriel Ravier 5dbd8faad5 [lld] Fixed a number of typos
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
2022-08-02 09:52:31 -04:00
Fangrui Song b3452f8f13 [ELF] redirectSymbols: skip versioned symbol combine if config->versionDefinitions.size() == 2 2022-07-31 17:47:09 -07:00
Fangrui Song c09d323599 [ELF] Move EhInputSection out of inputSections. NFC
inputSections temporarily contains EhInputSection objects mainly for
combineEhSections. Place EhInputSection objects into a new vector
ehInputSections instead of inputSections.
2022-07-31 11:58:08 -07:00
Fangrui Song 4b2b68d5ab [lld] Change vector to SmallVector. NFC
My lld executable is 1.6KiB smaller and some functions are now more efficient.
2022-07-30 18:11:21 -07:00
Fangrui Song efb7a71a13 [ELF] Support missing relocations in AArch64::getImplicitAddend() 2022-07-30 01:24:55 -07:00
Fangrui Song 4db7c7dbb4 [ELF] Remove one inputSections loop. NFC 2022-07-29 00:03:50 -07:00
Fangrui Song 6d0b42745e [ELF] addLibrary: fix a use-after-free bug in archiveName
It manifests as an incorrect name in --print-archive-stats=.
2022-07-26 14:36:57 -07:00
Fangrui Song cbcdb5248d [ELF] Simplify --build-id/--color-diagnostics with AliasArgs. NFC 2022-07-25 01:14:53 -07:00
Fangrui Song 85cfd91723 [ELF] Optimize some non-constant alignTo with alignToPowerOf2. NFC
My x86-64 lld executable is 2KiB smaller. .eh_frame writing gets faster as there
were lots of divisions.
2022-07-24 11:20:49 -07:00
Fangrui Song 50f5f37b07 [ELF] Internalize isBitcode. NFC 2022-07-22 11:56:46 -07:00
Fangrui Song 242316bc27 [ELF] Simplify createObjectFile/createLazyFile. NFC
And avoid redundant identify_magic test.
2022-07-22 01:26:12 -07:00
Cole Kissane ea61750c35 [NFC] Refactor llvm::zlib namespace
* 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
2022-07-08 11:19:07 -07:00
Jin Xin Ng 65001f5777
[LTO][ELF] Add selective --save-temps= option
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
2022-07-06 10:06:18 -07:00
Fangrui Song 9a572164d5 [ELF] Move InputFiles global variables (memoryBuffers, objectFiles, etc) into Ctx. NFC 2022-06-29 18:53:38 -07:00
Fangrui Song e980f16d52 [ELF] Move whyExtract/backwardReferences from LinkerDriver to Ctx. NFC
Ctx was recently added as a more suitable place for such singletons.
2022-06-29 17:34:31 -07:00
Nico Weber a2c1f7c90d [lld, ELF and mac] Add --time-trace=<file>, remove --time-trace-file=<file>
`--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
2022-06-23 15:46:22 -04:00
Jin Xin Ng 22f1273357
[ThinLTO][ELF] Add --thinlto-emit-index-files option
Allows ThinLTO indices to be written to disk on-the-fly/as-part-of “normal” linker execution. Previously ThinLTO indices could be written via --thinlto-index-only but that would cause the linker to exit early. For MLGO specifically, this enables saving the ThinLTO index files without having to restart the linker to collect data only available at later stages (i.e. output of --save-temps) of the linker's execution.

Note, this option does not currently work with:
--thinlto-object-suffix-replace, as this is intended to be used to consume minimized IR bitcode files while --thinlto-emit-index-files is intended to be run together with InProcessThinLTO (which cannot parse minimized IR).
--thinlto-prefix-replace  support is left unimplemented but can be implemented if needed

Differential Revision: https://reviews.llvm.org/D127777
2022-06-23 12:35:42 -07:00
Kazu Hirata 5413bf1bac Don't use Optional::hasValue (NFC) 2022-06-20 11:33:56 -07:00
Matthias Braun 850d53a197 LTO: Decide upfront whether to use opaque/non-opaque pointer types
LTO code may end up mixing bitcode files from various sources varying in
their use of opaque pointer types. The current strategy to decide
between opaque / typed pointers upon the first bitcode file loaded does
not work here, since we could be loading a non-opaque bitcode file first
and would then be unable to load any files with opaque pointer types
later.

So for LTO this:
- Adds an `lto::Config::OpaquePointer` option and enforces an upfront
  decision between the two modes.
- Adds `-opaque-pointers`/`-no-opaque-pointers` options to the gold
  plugin; disabled by default.
- `--opaque-pointers`/`--no-opaque-pointers` options with
  `-plugin-opt=-opaque-pointers`/`-plugin-opt=-no-opaque-pointers`
  aliases to lld; disabled by default.
- Adds an `-lto-opaque-pointers` option to the `llvm-lto2` tool.
- Changes the clang driver to pass `-plugin-opt=-opaque-pointers` to
  the linker in LTO modes when clang was configured with opaque
  pointers enabled by default.

This fixes https://github.com/llvm/llvm-project/issues/55377

Differential Revision: https://reviews.llvm.org/D125847
2022-06-01 18:05:53 -07:00
Alex Richardson 7c20e7ca86 [ELF] Support -plugin-opt=stats-file=
This flag is added by clang::driver::tools::addLTOOptions() and was causing
errors for me when building the llvm-test-suite repository with LTO and
-DTEST_SUITE_COLLECT_STATS=ON. This replaces the --stats-file= option
added in 1c04b52b25 since the flag is only
used for LTO and should therefore be in the -plugin-opt= namespace.

Additionally, this commit fixes the `REQUIRES: asserts` that was added in
948d05324a150a5a24e93bad07c9090d5b8bd129: the feature was never defined in
the lld test suite so it effectively disabled the test.

Reviewed By: MaskRay, MTC

Differential Revision: https://reviews.llvm.org/D124105
2022-05-09 15:04:40 +00:00
Shoaib Meenai 7cc328600e [ELF] Prevent LTO stripping of wrapped script-referenced symbols
After 1af25a9860, we stop unconditionally
retaining wrapped symbols, which means that LTO's summary-based global
dead stripping can eliminate them even if they'll be referenced by a
linker script after the wrapping is performed. Mark symbols referenced
in linker scripts as `referenced` in addition to `isUsedInRegularObj`,
so that the wrapping logic correctly sets `referencedAfterWrap` for the
symbols which will be referenced after wrapping, which will prevent LTO
from eliminating them.

An alternative would have been to change the `referencedAfterWrap` logic
to look at `isUsedInRegularObj` in addition to `referenced`, but
`isUsedInRegularObj` is also set in other places (e.g. for the entry
symbol), and it's not clear that we want `referencedAfterWrap` to take
all those places into account, so it seemed better to keep that logic
as-is and instead set `referenced` for linker script-referenced symbols.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D124433
2022-04-26 18:48:26 -07:00
Shoaib Meenai 2a04f5c455 [ELF] Drop unused original symbol after wrapping if not defined
We were previously only omitting the original of a wrapped symbol if it
was not used by an object file and undefined. We can tighten the second
condition to drop any symbol that isn't defined instead, which lets us
drop a previous check (added in https://reviews.llvm.org/D118756) that
was only covering some such symbols.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D124065
2022-04-22 16:47:15 -07:00
Shoaib Meenai 1af25a9860 [ELF] Fix wrapping symbols produced during LTO codegen
We were previously not correctly wrapping symbols that were only
produced during LTO codegen and unreferenced before then, or symbols
only referenced from such symbols. The root cause was that we weren't
marking the wrapped symbol as used if we only saw the use after LTO
codegen, leading to the failed wrapping.

Fix this by explicitly tracking whether a symbol will become referenced
after wrapping is done. We can use this property to tell LTO to preserve
such symbols, instead of overload isUsedInRegularObj for this purpose.
Since we're no longer setting isUsedInRegularObj for all symbols which
will be wrapped, its value at the time of performing the wrapping in the
symbol table will accurately reflect whether the symbol was actually
used in an object (including in an LTO-generated object), and we can
propagate that value to the wrapped symbol and thereby ensure we wrap
correctly.

This incorrect wrapping was the only scenario I was aware of where we
produced an invalid PLT relocation, which D123985 started diagnosing,
and with it fixed, we lose the test for that diagnosis. I think it's
worth keeping the diagnosis though, in case we run into other issues in
the future which would be caught by it.

Fixes PR50675.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D124056
2022-04-22 16:45:21 -07:00
Nikita Popov b8f50abd04 [lld] Remove support for legacy pass manager
This removes options for performing LTO with the legacy pass
manager in LLD. Options that explicitly enable the new pass manager
are retained as no-ops.

Differential Revision: https://reviews.llvm.org/D123219
2022-04-07 10:17:31 +02:00