Commit Graph

45 Commits

Author SHA1 Message Date
Kazu Hirata c68af42fa8 [lld] Use std::nullopt instead of None (NFC)
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-02 23:12:36 -08:00
Fangrui Song 026e797367 [lld-macho] Change most Optional to std::optional 2022-11-27 16:54:07 -08:00
Zequan Wu 84be92d26f Reland "[LTO][COFF] Use bitcode file names in lto native object file names."
This reverts commit 3410808294 with fixes.
2022-11-22 13:46:42 -08:00
Roman Lebedev 3410808294
Revert "Reland "[LTO][COFF] Use bitcode file names in lto native object file names.""
Breaks build of LLVMgold here:
```
/repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1108:19: error: no matching function for call to 'localCache'
    Cache = check(localCache("ThinLTO", "Thin", options::cache_dir, AddBuffer));
                  ^~~~~~~~~~
/repositories/llvm-project/llvm/include/llvm/Support/Caching.h:72:21: note: candidate function not viable: no known conversion from '(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1102:20)' to 'llvm::AddBufferFn' (aka 'function<void (unsigned int, const llvm::Twine &, std::unique_ptr<MemoryBuffer>)>') for 4th argument
Expected<FileCache> localCache(
                    ^
/repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1110:18: error: no viable conversion from '(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20)' to 'llvm::AddStreamFn' (aka 'function<Expected<std::unique_ptr<CachedFileStream>> (unsigned int, const llvm::Twine &)>')
  check(Lto->run(AddStream, Cache));
                 ^~~~~~~~~
/usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/std_function.h:375:7: note: candidate constructor not viable: no known conversion from '(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20)' to 'std::nullptr_t' for 1st argument
      function(nullptr_t) noexcept
      ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/std_function.h:386:7: note: candidate constructor not viable: no known conversion from '(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20)' to 'const std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream>> (unsigned int, const llvm::Twine &)> &' for 1st argument
      function(const function& __x)
      ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/std_function.h:404:7: note: candidate constructor not viable: no known conversion from '(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20)' to 'std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream>> (unsigned int, const llvm::Twine &)> &&' for 1st argument
      function(function&& __x) noexcept
      ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/std_function.h:435:2: note: candidate template ignored: requirement '_Callable<(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20) &, (lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20), std::__invoke_result<(lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20) &, unsigned int, const llvm::Twine &>>::value' was not satisfied [with _Functor = (lambda at /repositories/llvm-project/llvm/tools/gold/gold-plugin.cpp:1094:20) &]
        function(_Functor&& __f)
        ^
/repositories/llvm-project/llvm/include/llvm/LTO/LTO.h:278:25: note: passing argument to parameter 'AddStream' here
  Error run(AddStreamFn AddStream, FileCache Cache = nullptr);
                        ^

```

This reverts commit 387620aa8c.
2022-11-23 00:40:12 +03:00
Zequan Wu 387620aa8c Reland "[LTO][COFF] Use bitcode file names in lto native object file names."
This reverts commit eef5405f74.
2022-11-22 11:26:18 -08:00
Zequan Wu eef5405f74 Revert "[LTO][COFF] Use bitcode file names in lto native object file names."
This reverts commit 531ed6d5aa.
2022-11-22 10:55:05 -08:00
Zequan Wu 531ed6d5aa [LTO][COFF] Use bitcode file names in lto native object file names.
Currently the lto native object files have names like main.exe.lto.1.obj. In
PDB, those names are used as names for each compiland. Microsoft’s tool
SizeBench uses those names to present to users the size of each object files.
So, names like main.exe.lto.1.obj is not user friendly.

This patch makes the lto native object file names more readable by using
the bitcode file names as part of the file names. For example, if the input
bitcode file has path like "path/to/foo.obj", its corresponding lto native
object file path would be "path/to/main.exe.lto.foo.obj". Since the lto native
object file name only bothers PDB, this patch only changes the lld-linker's
behavior.

Reviewed By: tejohnson, MaskRay, #lld-macho

Differential Revision: https://reviews.llvm.org/D137217
2022-11-22 10:19:58 -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
Ying Yi ca875cb4fe [ThinLTO] a ThinLTO warning is added if cache_size_bytes or cache_size_files is too small for the current link job. The warning recommends the user to consider adjusting --thinlto-cache-policy.
A specific case for ThinLTO cache pruning is that the current build is huge, and the cache wasn't big enough to hold the intermediate object files of that build. So in doing that build, a file would be cached, and later in that same build it would be evicted. This was significantly decreasing the effectiveness of the cache. By giving this warning, the user could identify the required cache size/files and improve ThinLTO link speed.

Differential Revision: https://reviews.llvm.org/D135590
2022-11-14 12:27:29 +00:00
Jez Ng b945733026 [lld-macho] Map file should map symbols to their original bitcode file
... instead of mapping them to the intermediate object file.
This matches ld64.

Reviewed By: #lld-macho, Roger

Differential Revision: https://reviews.llvm.org/D136380
2022-10-21 22:49:02 -04:00
Leonard Grey a5764912fb [lld-macho] Hardlink -object_path_lto files to cache when possible
This is a follow-up to https://reviews.llvm.org/D131624 (specifically to https://reviews.llvm.org/D131624#3716584)

Differential revision: https://reviews.llvm.org/D133218
2022-09-07 14:27:43 -04:00
Leonard Grey 6c62795058 [lld-macho] Ensure cached objects are affected by `-object_path_lto`
This refactors LTO compile to look more like COFF, where cache hits and misses are all funneled through the same code path.

Previously, cache hits were *not* being saved to -object_path_lto, which led to them sometimes falling out of the cache before dsymutil could process them. As a side effect of the refactor, cached objects are now saved with -save-temps as well, which seems desirable.

(Deleted lld/test/MachO/lto-cache-dsymutil.ll and rolled it into lld/test/MachO/lto-object-path.ll, since the cache-only, non object path approach is unreliable anyway).

Differential Revision: https://reviews.llvm.org/D131624
2022-08-12 10:56:58 -04:00
Daniel Bertalan 2b2e858e9c [lld-macho] Handle filename being passed in -lto_object_path
Clang passes a filename rather than a directory in -lto_object_path when
using FullLTO. Previously, it was always treated it as a directory, so
lld would crash when it attempted to create temporary files inside it.

Fixes #54805

Differential Revision: https://reviews.llvm.org/D129705
2022-07-16 21:46:47 +02:00
Jez Ng d378268ead [lld-macho] Make `--icf=safe` work with LTO
Just matter of enabling the config option.

(Also changed the platform of the input test file to macOS, since that's
the default that we specify in the `%lld` substitution. The conflict was
causing errors when linking with LTO.)

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D127600
2022-06-12 17:26:08 -04:00
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
Jez Ng 8ce3750ff6 [lld-macho] Set FinalDefinitionInLinkageUnit on most LTO externs
Since Mach-O has a two-level namespace (unlike ELF), we can usually set
this property to true.

(I believe this setting is only available in the new LTO backend, so I
can't really use ld64 / libLTO's behavior as a reference here... I'm
just doing what I think is correct.)

See {D119294} for the work done to calculate the `interposable` used in
this diff.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D119506
2022-03-15 20:25:06 -04:00
Jez Ng 103e1d934a [lld-macho] Unset ExportDynamic where possible for LTO
By unsetting this property, we are now able to internalize more symbols
during LTO. I compared the output of `-save-temps` for both LLD and
ld64, and we now match ld64's behavior as far as `lto-internalize.ll` is
concerned.

(Thanks @smeenai for working on an initial version of this diff!)

Fixes https://github.com/llvm/llvm-project/issues/50574.

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D119372
2022-02-11 22:26:19 -05:00
Alexandre Ganea 83d59e05b2 Re-land [LLD] Remove global state in lldCommon
Move all variables at file-scope or function-static-scope into a hosting structure (lld::CommonLinkerContext) that lives at lldMain()-scope. Drivers will inherit from this structure and add their own global state, in the same way as for the existing COFFLinkerContext.

See discussion in https://lists.llvm.org/pipermail/llvm-dev/2021-June/151184.html

The previous land f860fe3622 caused issues in https://lab.llvm.org/buildbot/#/builders/123/builds/8383, fixed by 22ee510dac.

Differential Revision: https://reviews.llvm.org/D108850
2022-01-20 14:53:26 -05:00
Alexandre Ganea e6b153947d Revert [LLD] Remove global state in lldCommon
It seems to be causing issues on https://lab.llvm.org/buildbot/#/builders/123/builds/8383
2022-01-16 11:03:06 -05:00
Alexandre Ganea f860fe3622 [LLD] Remove global state in lldCommon
Move all variables at file-scope or function-static-scope into a hosting structure (lld::CommonLinkerContext) that lives at lldMain()-scope. Drivers will inherit from this structure and add their own global state, in the same way as for the existing COFFLinkerContext.

See discussion in https://lists.llvm.org/pipermail/llvm-dev/2021-June/151184.html

Differential Revision: https://reviews.llvm.org/D108850
2022-01-16 08:57:57 -05:00
Noah Shutty d788c44f5c [Support] Improve Caching conformance with Support library behavior
This diff makes several amendments to the local file caching mechanism
which was migrated from ThinLTO to Support in
rGe678c51177102845c93529d457b020f969125373 in response to follow-up
discussion on that commit.

Patch By: noajshu

Differential Revision: https://reviews.llvm.org/D113080
2021-11-04 13:00:44 -07:00
Noah Shutty e678c51177 [Support][ThinLTO] Move ThinLTO caching to LLVM Support library
We would like to move ThinLTO’s battle-tested file caching mechanism to
the LLVM Support library so that we can use it elsewhere in LLVM.

Patch By: noajshu

Differential Revision: https://reviews.llvm.org/D111371
2021-10-18 18:57:25 -07:00
Petr Hosek 8e46e34d24 Revert "[Support][ThinLTO] Move ThinLTO caching to LLVM Support library"
This reverts commit 92b8cc52bb since
it broke the gold plugin.
2021-10-18 12:24:05 -07:00
Noah Shutty 92b8cc52bb [Support][ThinLTO] Move ThinLTO caching to LLVM Support library
We would like to move ThinLTO’s battle-tested file caching mechanism to
the LLVM Support library so that we can use it elsewhere in LLVM.

Patch By: noajshu

Differential Revision: https://reviews.llvm.org/D111371
2021-10-18 12:08:49 -07:00
Jez Ng d9ab62ca3d [lld-macho] Initialize LTO backend with diagnostic handler
Failing to do so results in `std::bad_function_call` being
thrown when a pass tries to emit a diagnostic.

I've copied the relevant test over from LLD-ELF's test suite.

Reviewed By: #lld-macho, thevinster

Differential Revision: https://reviews.llvm.org/D109274
2021-09-04 17:40:07 -04:00
Leonard Grey c931ff72bd [lld-macho] Add LTO cache support
This adds support for the lld-only `--thinlto-cache-policy` option, as well as
implementations for ld64's `-cache_path_lto`, `-prune_interval_lto`,
`-prune_after_lto`, and `-max_relative_cache_size_lto`.

Test is adapted from lld/test/ELF/lto/cache.ll

Differential Revision: https://reviews.llvm.org/D105922
2021-07-15 12:56:13 -04:00
Nico Weber 3eb2fc4b50 [lld/mac] Partially implement -export_dynamic
This implements the part of -export_dynamic that adds external
symbols as dead strip roots even for executables.

It does not yet implement the effect -export_dynamic has for LTO.
I tried just replacing `config->outputType != MH_EXECUTE` with
`(config->outputType != MH_EXECUTE || config->exportDynamic)` in
LTO.cpp, but then local symbols make it into the symbol table too,
which is too much (and also doesn't match ld64). So punt on this
for now until I understand it better.
(D91583 may or may not be related too).

Differential Revision: https://reviews.llvm.org/D105482
2021-07-06 11:22:18 -04:00
Leonard Grey fe08e9c487 [lld-macho] Add support for LTO optimization level
Everything (including test) modified from ELF/COFF. Using the same syntax
(--lto-O3, etc) as ELF.

Differential Revision: https://reviews.llvm.org/D105223
2021-07-01 15:01:59 -04:00
Jez Ng ed4a4e3312 [lld-macho][nfc] Add accessors for commonly-used PlatformInfo fields
As discussed here: https://reviews.llvm.org/D100523#inline-951543

Reviewed By: #lld-macho, thakis, alexshap

Differential Revision: https://reviews.llvm.org/D100978
2021-04-21 15:43:56 -04:00
Alexander Shaposhnikov 5c835e1ae5 [lld][MachO] Add support for LC_VERSION_MIN_* load commands
This diff adds initial support for the legacy LC_VERSION_MIN_* load commands.

Test plan: make check-lld-macho

Differential revision: https://reviews.llvm.org/D100523
2021-04-21 05:41:14 -07:00
Jez Ng eb5b7d4497 [lld-macho] LTO: Unset VisibleToRegularObj where possible
This allows LLVM's LTO to internalize symbols that are not referenced
directly by regular objects. Naturally, this means we need to track
which symbols are referenced by regular objects. The approach taken here
is similar to LLD-COFF's: like the COFF port, we extend
`SymbolTable::insert()` to set the isVisibleToRegularObj bit. (LLD-ELF
relies on the Symbol constructor and `Symbol::mergeProperties()`, but
the Mach-O port does not have a `mergeProperties()` equivalent.)

From what I can tell, ld64 (which uses libLTO) doesn't do this
optimization at all. I'm not even sure libLTO provides a way to do this.
Not having ld64's behavior as a reference implementation is unfortunate;
instead, I am relying on LLD-ELF/COFF's behavior as references while
erring on the conservative side. In particular, LLD-MachO will only do
this optimization for executables right now.

We also don't attempt it when `-flat_namespace` is used -- otherwise
we'd need scan the symbol table to find matches for every un-namespaced
symbol reference, which is expensive.

internalize.ll is based off the LLD-ELF tests `internalize-basic.ll` and
`internalize-undef.ll`. Looks like @davide added some of LLD-ELF's internalize
tests, so adding him as a reviewer...

Reviewed By: #lld-macho, gkm

Differential Revision: https://reviews.llvm.org/D99105
2021-04-15 21:16:33 -04:00
Jez Ng 050a7a27ca [lld-macho] Support --thinlto-jobs
The test is loosely based off LLD-ELF's `thinlto.ll`. However, I
found that test questionable because the the -save_temps behavior it
checks for is identical regardless of whether we are running in single-
or multi-threaded mode. I tried writing a test based on `--time-trace`
but couldn't get it to run deterministically... so I've opted to just
skip checking that behavior for now.

Reviewed By: #lld-macho, gkm

Differential Revision: https://reviews.llvm.org/D99356
2021-04-08 12:21:01 -04:00
Jez Ng 817d98d841 [lld-macho][nfc] Refactor in preparation for 32-bit support
The main challenge was handling the different on-disk structures (e.g.
`mach_header` vs `mach_header_64`). I tried to strike a balance between
sprinkling `target->wordSize == 8` checks everywhere (branchy = slow, and ugly)
and templatizing everything (causes code bloat, also ugly). I think I struck a
decent balance by judicious use of type erasure.

Note that LLD-ELF has a similar architecture, though it seems to use more templating.

Linking chromium_framework takes about the same time before and after this
change:

      N           Min           Max        Median           Avg        Stddev
  x  20          4.52          4.67         4.595        4.5945   0.044423204
  +  20           4.5          4.71         4.575         4.582   0.056344803
  No difference proven at 95.0% confidence

Reviewed By: #lld-macho, oontvoo

Differential Revision: https://reviews.llvm.org/D99633
2021-04-02 18:46:39 -04:00
Jez Ng ae7aa9ed15 [lld-macho] Add time tracing for LTO
The test is similar to the one used for LLD-ELF.

Differential Revision: https://reviews.llvm.org/D99318
2021-03-26 18:14:10 -04:00
Greg McGary a170533632 [lld-macho][NFC] Drop unnecessary braces around simple if/for bodies
Minor cleanup

Differential Revision: https://reviews.llvm.org/D98758
2021-03-16 22:39:39 -07:00
Greg McGary fdc0c21973 [lld-macho][NFC] when reasonable, replace auto keyword with type names
lld policy discourages `auto`. Replace it with a type name whenever reasonable. Retain `auto` to avoid ...
* redundancy, as for decls such as `auto *t = mumble_cast<TYPE *>` or similar that specifies the result type on the RHS
* verbosity, as for iterators
* gratuitous suffering, as for lambdas

Along the way, add `const` when appropriate.

Note: a future diff will ...
* add more `const` qualifiers
* remove `opt::` when we are already `using llvm::opt`

Differential Revision: https://reviews.llvm.org/D98313
2021-03-09 22:08:32 -08:00
Jez Ng 55a32812fa [lld-macho] Filter TAPI re-exports by target
Previously, we were loading re-exports without checking whether
they were compatible with our target. Prior to {D97209}, it meant that
we were defining dylib symbols that were invalid -- usually a silent
failure unless our binary actually used them. D97209 exposed this as an
explicit error.

Along the way, I've extended our TAPI compatibility check to cover the
platform as well, instead of just checking the arch. To this end, I've
replaced MachO::Architecture with MachO::Target in our Config struct.

Reviewed By: #lld-macho, oontvoo

Differential Revision: https://reviews.llvm.org/D97867
2021-03-04 14:36:47 -05:00
Jez Ng 84579fc24f [lld-macho] Basic support for linkage and visibility attributes in LTO
When parsing bitcode, convert LTO Symbols to LLD Symbols in order to perform
resolution. The "winning" symbol will then be marked as Prevailing at LTO
compilation time. This is similar to what the other LLD ports do.

This change allows us to handle `linkonce` symbols correctly, and to deal with
duplicate bitcode symbols gracefully. Previously, both scenarios would result in
an assertion failure inside the LTO code, complaining that multiple Prevailing
definitions are not allowed.

While at it, I also added basic logic around visibility. We don't do anything
useful with it yet, but we do check that its value is valid. LLD-ELF appears to
use it only to set FinalDefinitionInLinkageUnit for LTO, which I think is just a
performance optimization.

From my local experimentation, the linker itself doesn't seem to do anything
differently when encountering linkonce / linkonce_odr / weak / weak_odr. So I've
only written a test for one of them. LLD-ELF has more, but they seem to mostly
be testing the intermediate bitcode output of their LTO backend...? I'm far from
an expert here though, so I might very well be missing things.

Reviewed By: #lld-macho, MaskRay, smeenai

Differential Revision: https://reviews.llvm.org/D94342
2021-02-25 13:27:40 -05:00
Jez Ng 697f4e429b [lld-macho] Run ObjCContractPass during LTO
Run the ObjCARCContractPass during LTO. The legacy LTO backend (under
LTO/ThinLTOCodeGenerator.cpp) already does this; this diff just adds that
behavior to the new LTO backend. Without that pass, the objc.clang.arc.use
intrinsic will get passed to the instruction selector, which doesn't know how to
handle it.

In order to test both the new and old pass managers, I've also added support for
the `--[no-]lto-legacy-pass-manager` flags.

P.S. Not sure if the ordering of the pass within the pipeline matters...

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D94547
2021-01-20 14:21:32 -05:00
Jez Ng e98b441a09 [lld-macho] Remove unnecessary llvm:: namespace prefixes 2021-01-09 12:44:35 -05:00
Jez Ng 29d3b0e471 [lld-macho] Add support for -mcpu, -mattr, -code-model in LTO
`-mcpu` and `-code-model` tests were copied from similar ones in
LLD-ELF.

There doesn't seem to be an equivalent test for `-mattr` in LLD-ELF, so
I've verified our behavior by cribbing a test from
CodeGen/X86/recip-fastmath.ll.

Reviewed By: #lld-macho, compnerd, MaskRay

Differential Revision: https://reviews.llvm.org/D92912
2020-12-10 15:57:51 -08:00
Jez Ng 95831a56d0 [lld-macho] Implement -object_path_lto
This makes it possible for STABS entries to reference the debug info
contained in the LTO-compiled output.

I'm not sure how to test the file mtime within llvm-lit -- GNU and BSD
`stat` take different command-line arguments. I've omitted the check for
now.

Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D92537
2020-12-10 15:57:51 -08:00
Nico Weber b2f00f24a3 [mac/lld] Include archive name in diagnostics
Also, for .o files, include full path as given on link command line.

Before:
    lld: error: undefined symbol [...], referenced from sandbox_logging.o

After:
    lld: error: undefined symbol [...], referenced from libseatbelt.a(sandbox_logging.o)

Move archiveName up to InputFile so we can consistently use toString()
to print InputFiles in diags, and pass it to the ObjFile ctor. This
matches the ELF and COFF ports.

Differential Revision: https://reviews.llvm.org/D92437
2020-12-01 23:00:25 -05:00
Jez Ng b768d57b36 [lld-macho] Add archive name and file modtime to STABS output
We should also set the modtime when running LTO. That will be done in a
future diff, together with support for the `-object_path_lto` flag.

Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D91318
2020-12-01 15:05:21 -08:00
Jez Ng 21f831134c [lld-macho] Add very basic support for LTO
Just enough to consume some bitcode files and link them. There's more
to be done around the symbol resolution API and the LTO config, but I don't yet
understand what all the various LTO settings do...

Reviewed By: #lld-macho, compnerd, smeenai, MaskRay

Differential Revision: https://reviews.llvm.org/D90663
2020-11-10 12:19:28 -08:00