[lld] 255ea48 - [ELF] Merge verdefIndex into versionId. NFC (#72208)
Fangrui Song via llvm-commits
llvm-commits at lists.llvm.org
Thu Nov 16 01:03:58 PST 2023
Author: Fangrui Song
Date: 2023-11-16T01:03:52-08:00
New Revision: 255ea486085fca79d21eb0082594579abdbd89d0
URL: https://github.com/llvm/llvm-project/commit/255ea486085fca79d21eb0082594579abdbd89d0
DIFF: https://github.com/llvm/llvm-project/commit/255ea486085fca79d21eb0082594579abdbd89d0.diff
LOG: [ELF] Merge verdefIndex into versionId. NFC (#72208)
The two fields are similar.
`versionId` is the Verdef index in the output file. It is set for
`--exclude-id=`, version script patterns, and `sym at ver` symbols.
`verdefIndex` is the Verdef index of a Sharedfile (SharedSymbol or a
copy-relocated Defined), the default value -1 is also used to indicate
that the symbol has not been matched by a version script pattern
(https://reviews.llvm.org/D65716).
It seems confusing to have two fields. Merge them so that we can
allocate one bit for #70130 (suppress --no-allow-shlib-undefined
error in the presence of a DSO definition).
Added:
Modified:
lld/ELF/InputFiles.cpp
lld/ELF/Relocations.cpp
lld/ELF/SymbolTable.cpp
lld/ELF/Symbols.cpp
lld/ELF/Symbols.h
lld/ELF/SyntheticSections.cpp
Removed:
################################################################################
diff --git a/lld/ELF/InputFiles.cpp b/lld/ELF/InputFiles.cpp
index 8c7f2c8773f2cbc..4b4d7d6db93cd57 100644
--- a/lld/ELF/InputFiles.cpp
+++ b/lld/ELF/InputFiles.cpp
@@ -1546,7 +1546,7 @@ template <class ELFT> void SharedFile::parse() {
SharedSymbol{*this, name, sym.getBinding(), sym.st_other,
sym.getType(), sym.st_value, sym.st_size, alignment});
if (s->file == this)
- s->verdefIndex = ver;
+ s->versionId = ver;
}
// Also add the symbol with the versioned name to handle undefined symbols
@@ -1563,7 +1563,7 @@ template <class ELFT> void SharedFile::parse() {
SharedSymbol{*this, saver().save(name), sym.getBinding(), sym.st_other,
sym.getType(), sym.st_value, sym.st_size, alignment});
if (s->file == this)
- s->verdefIndex = idx;
+ s->versionId = idx;
}
}
diff --git a/lld/ELF/Relocations.cpp b/lld/ELF/Relocations.cpp
index 6765461805dadb0..fe3d7f419e84aa6 100644
--- a/lld/ELF/Relocations.cpp
+++ b/lld/ELF/Relocations.cpp
@@ -309,7 +309,7 @@ static void replaceWithDefined(Symbol &sym, SectionBase &sec, uint64_t value,
size, &sec)
.overwrite(sym);
- sym.verdefIndex = old.verdefIndex;
+ sym.versionId = old.versionId;
sym.exportDynamic = true;
sym.isUsedInRegularObj = true;
// A copy relocated alias may need a GOT entry.
diff --git a/lld/ELF/SymbolTable.cpp b/lld/ELF/SymbolTable.cpp
index fe7edd5b0eb49aa..b3d97e4de779068 100644
--- a/lld/ELF/SymbolTable.cpp
+++ b/lld/ELF/SymbolTable.cpp
@@ -92,7 +92,6 @@ Symbol *SymbolTable::insert(StringRef name) {
memset(sym, 0, sizeof(Symbol));
sym->setName(name);
sym->partition = 1;
- sym->verdefIndex = -1;
sym->versionId = VER_NDX_GLOBAL;
if (pos != StringRef::npos)
sym->hasVersionSuffix = true;
@@ -235,10 +234,9 @@ bool SymbolTable::assignExactVersion(SymbolVersion ver, uint16_t versionId,
sym->getName().contains('@'))
continue;
- // If the version has not been assigned, verdefIndex is -1. Use an arbitrary
- // number (0) to indicate the version has been assigned.
- if (sym->verdefIndex == uint16_t(-1)) {
- sym->verdefIndex = 0;
+ // If the version has not been assigned, assign versionId to the symbol.
+ if (!sym->versionScriptAssigned) {
+ sym->versionScriptAssigned = true;
sym->versionId = versionId;
}
if (sym->versionId == versionId)
@@ -256,8 +254,8 @@ void SymbolTable::assignWildcardVersion(SymbolVersion ver, uint16_t versionId,
// so we set a version to a symbol only if no version has been assigned
// to the symbol. This behavior is compatible with GNU.
for (Symbol *sym : findAllByVersion(ver, includeNonDefault))
- if (sym->verdefIndex == uint16_t(-1)) {
- sym->verdefIndex = 0;
+ if (!sym->versionScriptAssigned) {
+ sym->versionScriptAssigned = true;
sym->versionId = versionId;
}
}
diff --git a/lld/ELF/Symbols.cpp b/lld/ELF/Symbols.cpp
index 671eb56f3404c95..734ca6bfcb4034c 100644
--- a/lld/ELF/Symbols.cpp
+++ b/lld/ELF/Symbols.cpp
@@ -683,3 +683,13 @@ void Symbol::resolve(const SharedSymbol &other) {
} else if (traced)
printTraceSymbol(other, getName());
}
+
+void Defined::overwrite(Symbol &sym) const {
+ if (isa_and_nonnull<SharedFile>(sym.file))
+ sym.versionId = VER_NDX_GLOBAL;
+ Symbol::overwrite(sym, DefinedKind);
+ auto &s = static_cast<Defined &>(sym);
+ s.value = value;
+ s.size = size;
+ s.section = section;
+}
diff --git a/lld/ELF/Symbols.h b/lld/ELF/Symbols.h
index 4addb79d1257914..e34a31e12f99a5e 100644
--- a/lld/ELF/Symbols.h
+++ b/lld/ELF/Symbols.h
@@ -313,11 +313,12 @@ class Symbol {
uint32_t auxIdx;
uint32_t dynsymIndex;
- // This field is a index to the symbol's version definition.
- uint16_t verdefIndex;
-
- // Version definition index.
+ // If `file` is SharedFile (for SharedSymbol or copy-relocated Defined), this
+ // represents the Verdef index within the input DSO, which will be converted
+ // to a Verneed index in the output. Otherwise, this represents the Verdef
+ // index (VER_NDX_LOCAL, VER_NDX_GLOBAL, or a named version).
uint16_t versionId;
+ uint8_t versionScriptAssigned : 1;
void setFlags(uint16_t bits) {
flags.fetch_or(bits, std::memory_order_relaxed);
@@ -355,14 +356,7 @@ class Defined : public Symbol {
size(size), section(section) {
exportDynamic = config->exportDynamic;
}
- void overwrite(Symbol &sym) const {
- Symbol::overwrite(sym, DefinedKind);
- sym.verdefIndex = -1;
- auto &s = static_cast<Defined &>(sym);
- s.value = value;
- s.size = size;
- s.section = section;
- }
+ void overwrite(Symbol &sym) const;
static bool classof(const Symbol *s) { return s->isDefined(); }
diff --git a/lld/ELF/SyntheticSections.cpp b/lld/ELF/SyntheticSections.cpp
index 0f7ebf9d7ba840b..2b32eb3a0fe3558 100644
--- a/lld/ELF/SyntheticSections.cpp
+++ b/lld/ELF/SyntheticSections.cpp
@@ -3140,10 +3140,8 @@ bool VersionTableSection::isNeeded() const {
void elf::addVerneed(Symbol *ss) {
auto &file = cast<SharedFile>(*ss->file);
- if (ss->verdefIndex == VER_NDX_GLOBAL) {
- ss->versionId = VER_NDX_GLOBAL;
+ if (ss->versionId == VER_NDX_GLOBAL)
return;
- }
if (file.vernauxs.empty())
file.vernauxs.resize(file.verdefs.size());
@@ -3152,10 +3150,10 @@ void elf::addVerneed(Symbol *ss) {
// already allocated one. The verdef identifiers cover the range
// [1..getVerDefNum()]; this causes the vernaux identifiers to start from
// getVerDefNum()+1.
- if (file.vernauxs[ss->verdefIndex] == 0)
- file.vernauxs[ss->verdefIndex] = ++SharedFile::vernauxNum + getVerDefNum();
+ if (file.vernauxs[ss->versionId] == 0)
+ file.vernauxs[ss->versionId] = ++SharedFile::vernauxNum + getVerDefNum();
- ss->versionId = file.vernauxs[ss->verdefIndex];
+ ss->versionId = file.vernauxs[ss->versionId];
}
template <class ELFT>
More information about the llvm-commits
mailing list