[lld] r307364 - [ELF] - Handle symbols with default version early.
George Rimar via llvm-commits
llvm-commits at lists.llvm.org
Fri Jul 7 01:29:51 PDT 2017
Author: grimar
Date: Fri Jul 7 01:29:51 2017
New Revision: 307364
URL: http://llvm.org/viewvc/llvm-project?rev=307364&view=rev
Log:
[ELF] - Handle symbols with default version early.
This fixes last testcase provided in PR28414.
In short issue is next: when we had X@@Version symbol in object A,
we did not resolve it to X early. Then when in another object B
we had reference to undefined X, symbol X from archive was fetched.
Since both archive and object A contains another symbol Z, duplicate
symbol definition was triggered as a result.
Correct behavior is to use X@@Version from object A instead and do not fetch
any symbols from archive.
Differential revision: https://reviews.llvm.org/D35059
Added:
lld/trunk/test/ELF/Inputs/symver-archive1.s
lld/trunk/test/ELF/Inputs/symver-archive2.s
lld/trunk/test/ELF/symver-archive.s
Modified:
lld/trunk/ELF/SymbolTable.cpp
Modified: lld/trunk/ELF/SymbolTable.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/SymbolTable.cpp?rev=307364&r1=307363&r2=307364&view=diff
==============================================================================
--- lld/trunk/ELF/SymbolTable.cpp (original)
+++ lld/trunk/ELF/SymbolTable.cpp Fri Jul 7 01:29:51 2017
@@ -211,6 +211,13 @@ static uint8_t getMinVisibility(uint8_t
// Find an existing symbol or create and insert a new one.
template <class ELFT>
std::pair<Symbol *, bool> SymbolTable<ELFT>::insert(StringRef Name) {
+ // <name>@@<version> means the symbol is the default version. In that
+ // case symbol <name> must exist and <name>@@<version> will be used to
+ // resolve references to <name>.
+ size_t Pos = Name.find("@@");
+ if (Pos != StringRef::npos)
+ Name = Name.take_front(Pos);
+
auto P = Symtab.insert(
{CachedHashStringRef(Name), SymIndex((int)SymVector.size(), false)});
SymIndex &V = P.first->second;
@@ -712,31 +719,14 @@ void SymbolTable<ELFT>::assignWildcardVe
B->symbol()->VersionId = VersionId;
}
-static bool isDefaultVersion(SymbolBody *B) {
- return B->isInCurrentDSO() && B->getName().find("@@") != StringRef::npos;
-}
-
// This function processes version scripts by updating VersionId
// member of symbols.
template <class ELFT> void SymbolTable<ELFT>::scanVersionScript() {
// Symbol themselves might know their versions because symbols
// can contain versions in the form of <name>@<version>.
// Let them parse and update their names to exclude version suffix.
- for (Symbol *Sym : SymVector) {
- SymbolBody *Body = Sym->body();
- bool IsDefault = isDefaultVersion(Body);
- Body->parseSymbolVersion();
-
- if (!IsDefault)
- continue;
-
- // <name>@@<version> means the symbol is the default version. If that's the
- // case, the symbol is not used only to resolve <name> of version <version>
- // but also undefined unversioned symbols with name <name>.
- SymbolBody *S = find(Body->getName());
- if (S && S->isUndefined())
- S->copy(Body);
- }
+ for (Symbol *Sym : SymVector)
+ Sym->body()->parseSymbolVersion();
// Handle edge cases first.
handleAnonymousVersion();
Added: lld/trunk/test/ELF/Inputs/symver-archive1.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/Inputs/symver-archive1.s?rev=307364&view=auto
==============================================================================
--- lld/trunk/test/ELF/Inputs/symver-archive1.s (added)
+++ lld/trunk/test/ELF/Inputs/symver-archive1.s Fri Jul 7 01:29:51 2017
@@ -0,0 +1,6 @@
+.text
+.globl x
+.type x, @function
+x:
+
+.symver x, xx@@VER
Added: lld/trunk/test/ELF/Inputs/symver-archive2.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/Inputs/symver-archive2.s?rev=307364&view=auto
==============================================================================
--- lld/trunk/test/ELF/Inputs/symver-archive2.s (added)
+++ lld/trunk/test/ELF/Inputs/symver-archive2.s Fri Jul 7 01:29:51 2017
@@ -0,0 +1 @@
+call xx at PLT
Added: lld/trunk/test/ELF/symver-archive.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/symver-archive.s?rev=307364&view=auto
==============================================================================
--- lld/trunk/test/ELF/symver-archive.s (added)
+++ lld/trunk/test/ELF/symver-archive.s Fri Jul 7 01:29:51 2017
@@ -0,0 +1,15 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t1
+# RUN: rm -f %t.a
+# RUN: llvm-ar rcs %t.a %t1
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %S/Inputs/symver-archive1.s -o %t2.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %S/Inputs/symver-archive2.s -o %t3.o
+# RUN: ld.lld -o %t.out %t2.o %t3.o %t.a
+
+.text
+.globl x
+.type x, @function
+x:
+
+.globl xx
+xx = x
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