9 Commits

Author SHA1 Message Date
Fangrui Song
16be2c0555
[ELF] Add VersionNode lexer state for better version script parsing
... so that `local:*;` will be lexed as three tokens instead of a single
one in a version node. This is used by both version scripts and dynamic
lists. Fix #174363

In addition, clean up special code for space-separated `local :` and `global :`.

This patch brings our lexer behavior closer to GNU ld. While GNU ld
additionally rejects more characters like `~/+,=`, we don't implement
this additional validation.

Pull Request: https://github.com/llvm/llvm-project/pull/174530
2026-01-06 22:19:44 -08:00
Fangrui Song
d96a93ff00
ELF: Use index 0 for unversioned undefined symbols (#168189)
The GNU documentation is ambiguous about the version index for
unversioned undefined symbols. The current specification at
https://sourceware.org/gnu-gabi/program-loading-and-dynamic-linking.txt
defines VER_NDX_LOCAL (0) as "The symbol is private, and is not
available outside this object."

However, this naming is misleading for undefined symbols. As suggested
in
discussions, VER_NDX_LOCAL should conceptually be VER_NDX_NONE and apply
to unversioned undefined symbols as well.

GNU ld has used index 0 for unversioned undefined symbols both before
version 2.35 (see https://sourceware.org/PR26002) and in the upcoming
2.46 release (see https://sourceware.org/PR33577). This change aligns
with GNU ld's behavior by switching from index 1 to index 0.

While here, add a test to dso-undef-extract-lazy.s that undefined
symbols of index 0 in DSO are treated as unversioned symbols.
2025-11-22 20:54:50 +00:00
Fangrui Song
81cebfd008 [ELF][test] Change -o %t to -o /dev/null if the output is not needed 2020-02-12 21:54:50 -08:00
George Rimar
938db706fe [LLD][ELF] - Update test cases after llvm-readobj output format change.
The change was:

SHT_GNU_verdef { -> VersionDefinitions [
SHT_GNU_verneed { -> VersionRequirements [
Version symbols [ -> VersionSymbols [
EH_FRAME Header [ -> EHFrameHeader {

llvm-svn: 375096
2019-10-17 10:23:59 +00:00
George Rimar
a8346cee8a [LLD][ELF] - Update test cases after llvm-readobj change.
https://reviews.llvm.org/D68704 changed the output format.

llvm-svn: 374542
2019-10-11 12:27:20 +00:00
Fangrui Song
e28a70daf4 [ELF] Consistently prioritize non-* wildcards overs "*" in version scripts
We prioritize non-* wildcards overs VER_NDX_LOCAL/VER_NDX_GLOBAL "*".
This patch generalizes the rule to "*" of other versions and thus fixes PR40176.
I don't feel strongly about this GNU linkers' behavior but the
generalization simplifies code.

Delete `config->defaultSymbolVersion` which was used to special case
VER_NDX_LOCAL/VER_NDX_GLOBAL "*".

In `SymbolTable::scanVersionScript`, custom versions are handled the same
way as VER_NDX_LOCAL/VER_NDX_GLOBAL. So merge
`config->versionScript{Locals,Globals}` into `config->versionDefinitions`.
Overall this seems to simplify the code.

In `SymbolTable::assign{Exact,Wildcard}Versions`,
`sym->verdefIndex == config->defaultSymbolVersion` is changed to
`verdefIndex == UINT32_C(-1)`.
This allows us to give duplicate assignment diagnostics for
`{ global: foo; };` `V1 { global: foo; };`

In test/linkerscript/version-script.s:
  vs_index of an undefined symbol changes from 0 to 1. This doesn't matter (arguably 1 is better because the binding is STB_GLOBAL) because vs_index of an undefined symbol is ignored.

Reviewed By: ruiu

Differential Revision: https://reviews.llvm.org/D65716

llvm-svn: 367869
2019-08-05 14:31:39 +00:00
James Henderson
4ba1777a2d [ELF] Remove checking for spurious '@' at the end of dynamic sym names
llvm-readobj currently has a bug (see PR40097) where it prints '@' at
the end of unversioned dynamic symbols. This bug will be fixed in a
separate later commit, but these tests need fixing first.

Reviewed by: ruiu, Higuoxing

Differential Revision: https://reviews.llvm.org/D56388

llvm-svn: 350614
2019-01-08 10:50:59 +00:00
Igor Kudrin
c844524e46 [ELF] Process linker scripts deeper when declaring symbols.
We should process symbols inside output section declarations the same way as top-level ones.

Differential Revision: https://reviews.llvm.org/D43008

llvm-svn: 326305
2018-02-28 05:55:56 +00:00
George Rimar
c4ccfb5d93 [ELF] - Define linkerscript symbols early.
Currently symbols assigned or created by linkerscript are not processed early
enough. As a result it is not possible to version them or assign any other flags/properties.

Patch creates Defined symbols for -defsym and linkerscript symbols early,
so that issue from above can be addressed.

It is based on Rafael Espindola's version of D38239 patch.

Fixes PR34121.

Differential revision: https://reviews.llvm.org/D41987

llvm-svn: 323729
2018-01-30 09:04:27 +00:00