Commit Graph

880 Commits

Author SHA1 Message Date
Peter Smith
ba476d0b83 [LLD][ELF][AArch64] Discard .ARM.attributes sections (#125838)
LLVM has started to emit AArch64 build attributes sections called
.ARM.attributes. LLD does not yet have support for these so they are
accumulating in the ELF output. As the first part of that support
discard all the .ARM.attributes sections. This can be built upon by the
full implementation in LLD.

The build attributes specification only defines build attributes for
relocatable objects. The intention for LLD is that files of type ET_EXEC
and ET_SHARED will not have a build attributes in the output. A
relocatable link with -r will need a merged build attributes, but until
the merge is implemented it is better to discard.
2025-02-05 14:04:21 -05:00
Fangrui Song
d6fa74ab3d [ELF] Merge exportDynamic/isExported and remove Symbol::includeInDynsym
Commit 3733ed6f1c introduced isExported to
cache includeInDynsym. If we don't unnecessarily set isExported for
undefined symbols, exportDynamic/includeInDynsym can be replaced with
isExported.
2025-01-30 22:24:04 -08:00
Fangrui Song
84af3ee512 [ELF] Replace Fatal with Err 2025-01-26 16:13:52 -08:00
Fangrui Song
c1f10ef0a5 [ELF] SHF_LINK_ORDER: replace Fatal with ErrAlways
In LLD_IN_TEST=2 mode, when a thread calls Fatal, there will be no
output even if the process exits with code 1. Change the Fatal to
ErrAlways (not-recoverable) as subsequent code assumes SHF_LINK_ORDER
sh_link is correct.
2025-01-25 18:13:42 -08:00
Fangrui Song
f21c35d54f [ELF] Replace some Fatal with Err
In LLD_IN_TEST=2 mode, when a thread calls Fatal, there will be no
output even if the process exits with code 1. Change a few Fatal to
recoverable Err.
2025-01-25 17:29:28 -08:00
Fangrui Song
4f48048171 [ELF] SHF_MERGE: avoid Fatal
In LLD_IN_TEST=2 mode, when a thread calls Fatal, there will be no
output even if the process exits with code 1.
2025-01-25 15:28:17 -08:00
Fangrui Song
e00f1f8436 [ELF] Error for executable .note.GNU-stack unless -z execstack or -r
.note.GNU-stack with the SHF_EXECINSTR flag requires an executable
stack. This is exceedingly rare. We report an error to force
the user to explicitly request an executable stack.

Close #121234

Pull Request: https://github.com/llvm/llvm-project/pull/124068
2025-01-23 12:32:54 -05:00
Fangrui Song
53544fc15f [ELF] Respect ltoCanOmit for symbols in non-prevailing COMDAT
A linkonce_odr definition can be omitted in LTO compilation if
`canBeOmittedFromSymbolTable()` is true in all bitcode files.

Currently, we don't respect the `canBeOmittedFromSymbolTable()` bit from
symbols in a non-prevailing COMDAT, which could lead to incorrect
omission of a definition when merging a prevailing linkonce_odr and a
non-prevailing weak_odr, e.g. an implicit template instantiation and an
explicit template instantiation.

To fix #111341, allow the non-prevailing COMDAT code path to clear the
`ltoCanOmit` bit, so that `VisibleToRegularObj` could be false in
LTO.cpp. We could resolve either an Undefined or a Defined. For
simplicity, just use a Defined like the prevailing case (similar to how
we resolve symbols in ObjectFile COMDAT reviews.llvm.org/D120626).

Pull Request: https://github.com/llvm/llvm-project/pull/119332
2024-12-11 08:55:05 -08:00
Fangrui Song
18538e2134 Revert "[ELF] Optimize parseSymbolVersion"
This reverts commit 2b129dacdd.

parseSymbolVersion can be combined with computeIsPreemptible,
making hasVersionSyms unneeded.
2024-12-08 17:50:16 -08:00
Fangrui Song
fe0d0a9e62 [ELF] Merge numSymbols and numELFSyms 2024-12-08 15:59:03 -08:00
Fangrui Song
2b129dacdd [ELF] Optimize parseSymbolVersion
We can just scan objectFiles and sharedFiles that have versioned symbols
to skip scanning the global symtab. While we won't suggest __wrap_foo
for undefined __wrap_foo@v1 when --wrap=foo@v1 is specified
(internalFile isn't scanned), this edge case difference is acceptable.
2024-12-08 12:32:55 -08:00
Fangrui Song
c650880958 [ELF] Simplify handling of exportDynamic and canBeOmittedFromSymbolTable
When computing whether a defined symbol is exported, we set
`exportDynamic` in Defined and CommonSymbol's ctor and merge the bit in
symbol resolution. The complexity is for the LTO special case
canBeOmittedFromSymbolTable, which can be simplified by introducing a
new bit.

We might simplify the state by caching includeInDynsym in exportDynamic
in the future.
2024-12-08 09:33:48 -08:00
Fangrui Song
8669028c18 [ELF] Remove unneeded sym->file check
After #78944 and some follow-ups, sym->file, unless in the initial
Placeholder stage, is guaranteed to be non-null.
2024-12-07 20:46:02 -08:00
Fangrui Song
a09df64f40 [ELF] postParse: remove some branches in the fast path 2024-12-01 14:18:10 -08:00
Fangrui Song
9becc4a3c9 [ELF] ObjFile::parse: check EM_AARCH64 for SHT_AARCH64_MEMTAG_GLOBAL_STATIC
and reorder sh_type checks to make SHT_PROGBITS/SHT_GROUP fast.
2024-12-01 12:03:35 -08:00
Fangrui Song
1f13713dbb [ELF] Change getSrcMsg to use ELFSyncStream. NFC 2024-11-29 17:18:22 -08:00
Fangrui Song
666de79595 [ELF] Move some ObjFile members to ELFFileBase to simplify getSrcMsg 2024-11-29 15:48:46 -08:00
Fangrui Song
1cd627562b [ELF] Remove unneeded Twine in ELFSyncStream 2024-11-24 12:13:02 -08:00
Fangrui Song
c790d6f53f [ELF] isCompatile: avoid a toStr and 2 ErrAlways 2024-11-24 11:30:21 -08:00
Fangrui Song
d4bed617f4 [ELF] -r: keep sh_entsize for SHF_MERGE sections with relocations
Follow-up to the NFC refactoring
43e3871a32 and test cleanup
3cecf17065.

SHF_MERGE sections with relocations are handled as InputSection (without
duplicate elimination). The output section retains the original
sh_entsize in non-relocatable links. This patch ports the behavior for
relocatable links as well.

https://github.com/ClangBuiltLinux/linux/issues/2057
2024-11-23 14:32:32 -08:00
Fangrui Song
43e3871a32 [ELF] Make section member orders consistent
SectionBase, InputSectionBase, InputSection, MergeInputSection, and
OutputSection have different member orders. Make them consistent and
adopt the order similar to the raw Elf64_Shdr.
2024-11-23 14:22:24 -08:00
Fangrui Song
dbf37e956a [ELF] Move InputFile storage from make<> to LinkerDriver::files 2024-11-16 23:50:35 -08:00
Fangrui Song
2991a4e209 [ELF] Replace functions bAlloc/saver/uniqueSaver with member access 2024-11-16 22:34:13 -08:00
Fangrui Song
483516fd83 [ELF] Remove unneeded Twine() 2024-11-16 20:32:44 -08:00
Fangrui Song
c1a6defd9f [ELF] Make RelType a struct type
otherwise operator<<(const ELFSyncStream &s, RelType type) applies to
non-reloc-type uint32_t, which can be confusing.
2024-11-16 20:26:34 -08:00
Fangrui Song
33ff9e43b4 [ELF] Move SharedFile::vernauxNum to Ctx 2024-11-16 17:00:51 -08:00
Fangrui Song
3b75a5c4c8 [ELF] Replace message(...) with Msg(ctx) 2024-11-16 15:34:42 -08:00
Fangrui Song
a626eb2a2f [ELF] Pass ctx to bAlloc/saver/uniqueSaver 2024-11-16 15:20:21 -08:00
Fangrui Song
38870fe124 [ELF] Remove unneeded toString(Error) when using ELFSyncStream 2024-11-16 13:22:06 -08:00
Fangrui Song
58a971f42f [ELF] Replace contex-less toString(x) with toStr(ctx, x)
so that we can remove the global `ctx` from toString implementations.
Rename lld::toString (to lld::elf::toStr) to simplify name lookup (we
have many llvm::toString and another lld::toString(const llvm::opt::Arg
&)).
2024-11-16 11:58:10 -08:00
Fangrui Song
942928f3df [ELF] Migrate away from global ctx 2024-11-14 23:04:18 -08:00
Fangrui Song
c13258ac49 [ELF] Replace log with Log(ctx) 2024-11-07 09:30:20 -08:00
Fangrui Song
9b058bb42d [ELF] Replace errorOrWarn(...) with Err 2024-11-06 22:33:51 -08:00
Fangrui Song
f8bae3af74 [ELF] Replace warn(...) with Warn 2024-11-06 22:19:31 -08:00
Fangrui Song
09c2c5e1e9 [ELF] Replace error(...) with ErrAlways or Err
Most are migrated to ErrAlways mechanically.
In the future we should change most to Err.
2024-11-06 22:04:52 -08:00
Fangrui Song
63c6fe4a0b [ELF] Replace fatal(...) with Fatal or Err 2024-11-06 21:17:26 -08:00
Fangrui Song
201d7607f8 [ELF] Add context-aware diagnostic functions (#112319)
The current diagnostic functions log/warn/error/fatal lack a context
argument and call the global `lld::errorHandler()`, which prevents
multiple lld instances in one process.

This patch introduces context-aware replacements:

* log => Log(ctx)
* warn => Warn(ctx)
* errorOrWarn => Err(ctx)
* error => ErrAlways(ctx)
* fatal => Fatal(ctx)

Example: `errorOrWarn(toString(f) + "xxx")` => `Err(ctx) << f << "xxx"`.
(`toString(f)` is shortened to `f` as a bonus and may access `ctx`
without accessing the global variable (see `Target.cpp`)).

`ctx.e = &context->e;` can be replaced with a non-global Errorhandler
when `ctx` becomes a local variable.

(For the ELF port, the long term goal is to eliminate `error`. Most can
be straightforwardly converted to `Err(ctx)`.)
2024-11-06 08:25:58 -08:00
Fangrui Song
fe8af49a1b [ELF] Pass Ctx & to Defined & CommonSymbol 2024-10-20 01:38:16 +00:00
Fangrui Song
dbd197118d [ELF] Pass Ctx & to Symbol 2024-10-11 23:34:43 -07:00
Fangrui Song
dd326b1225 [ELF] Pass Ctx & 2024-10-11 21:10:05 -07:00
Fangrui Song
6dd773b650 [ELF] Pass Ctx & 2024-10-11 20:15:02 -07:00
Fangrui Song
1c28f31133 [ELF] Pass Ctx & 2024-10-11 18:35:02 -07:00
Fangrui Song
b672071ba5 [ELF] Pass Ctx & to InputFile 2024-10-06 18:09:52 -07:00
Fangrui Song
f2b0133858 [ELF] Move static nextGroupId isInGroup to LinkerDriver 2024-10-06 17:38:35 -07:00
Fangrui Song
f1dccda1b5 [ELF] Pass Ctx & to Symbols 2024-10-06 17:05:43 -07:00
Fangrui Song
49865107d4 [ELF] Pass Ctx & to InputFiles 2024-10-06 11:27:24 -07:00
Fangrui Song
b3e0bd3d28 [ELF] Pass Ctx & to Arch/ 2024-10-06 00:31:51 -07:00
Fangrui Song
6d03a69034 [ELF] Pass Ctx & to Arch/ 2024-10-06 00:14:12 -07:00
Fangrui Song
c4c34f0474 [ELF] Pass Ctx & to InputFiles 2024-10-03 23:06:18 -07:00
Fangrui Song
079b8327ec [ELF] Pass Ctx & to InputFiles and SyntheticSections 2024-09-29 16:06:47 -07:00