[all-commits] [llvm/llvm-project] 7ed22a: [ELF] Apply version script patterns to non-default...

[Fangrui Song via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 7ed22a6fa90cbdc70d6806c1121a0c50c1978dce
      https://github.com/llvm/llvm-project/commit/7ed22a6fa90cbdc70d6806c1121a0c50c1978dce
  Author: Fangrui Song <i at maskray.me>
  Date:   2021-08-04 (Wed, 04 Aug 2021)

  Changed paths:
    M lld/ELF/Config.h
    M lld/ELF/Driver.cpp
    M lld/ELF/ScriptParser.cpp
    M lld/ELF/SymbolTable.cpp
    M lld/ELF/SymbolTable.h
    M lld/ELF/Symbols.cpp
    R lld/test/ELF/version-script-extern-exact.s
    R lld/test/ELF/version-script-extern-wildcards.s
    R lld/test/ELF/version-script-extern.s
    M lld/test/ELF/version-script-noundef.s
    A lld/test/ELF/version-script-symver-extern.s
    M lld/test/ELF/version-script-symver.s

  Log Message:
  -----------
  [ELF] Apply version script patterns to non-default version symbols

Currently version script patterns are ignored for .symver produced
non-default version (single @) symbols. This makes such symbols
not localizable by `local:`, e.g.

```
.symver foo3_v1,foo3 at v1
.globl foo_v1
foo3_v1:

ld.lld --version-script=a.ver -shared a.o
# In a.out, foo3 at v1 is incorrectly exported.
```

This patch adds the support:

* Move `config->versionDefinitions[VER_NDX_LOCAL].patterns` to `config->versionDefinitions[versionId].localPatterns`
* Rename `config->versionDefinitions[versionId].patterns` to `config->versionDefinitions[versionId].nonLocalPatterns`
* Allow `findAllByVersion` to find non-default version symbols when `includeNonDefault` is true. (Note: `symtab` keys do not have `@@`)
* Make each pattern check both the unversioned `pat.name` and the versioned `${pat.name}@${v.name}`
* `localPatterns` can localize `${pat.name}@${v.name}`. `nonLocalPatterns` can prevent localization by assigning `verdefIndex` (before `parseSymbolVersion`).

---

If a user notices new `undefined symbol` errors with a version script containing
`local: *;`, the issue is likely due to a missing `global:` pattern.

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D107234