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

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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@v1
.globl foo_v1
foo3_v1:

ld.lld --version-script=a.ver -shared a.o
# In a.out, foo3@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
This commit is contained in:
Fangrui Song
2021-08-04 09:02:11 -07:00
parent 3bc8ce5dd7
commit 7ed22a6fa9
12 changed files with 121 additions and 224 deletions
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9
lld/ELF/ScriptParser.cpp
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@@ -1496,9 +1496,9 @@ void ScriptParser::readAnonymousDeclaration() {
std::vector<SymbolVersion> globals;
std::tie(locals, globals) = readSymbols();
for (const SymbolVersion &pat : locals)
config->versionDefinitions[VER_NDX_LOCAL].patterns.push_back(pat);
config->versionDefinitions[VER_NDX_LOCAL].localPatterns.push_back(pat);
for (const SymbolVersion &pat : globals)
config->versionDefinitions[VER_NDX_GLOBAL].patterns.push_back(pat);
config->versionDefinitions[VER_NDX_GLOBAL].nonLocalPatterns.push_back(pat);
expect(";");
}
@@ -1510,13 +1510,12 @@ void ScriptParser::readVersionDeclaration(StringRef verStr) {
std::vector<SymbolVersion> locals;
std::vector<SymbolVersion> globals;
std::tie(locals, globals) = readSymbols();
for (const SymbolVersion &pat : locals)
config->versionDefinitions[VER_NDX_LOCAL].patterns.push_back(pat);
// Create a new version definition and add that to the global symbols.
VersionDefinition ver;
ver.name = verStr;
ver.patterns = globals;
ver.nonLocalPatterns = std::move(globals);
ver.localPatterns = std::move(locals);
ver.id = config->versionDefinitions.size();
config->versionDefinitions.push_back(ver);