Revert r307364: [ELF] - Handle symbols with default version early.

This reverts commit r307364 because that change is likely to have
caused https://bugs.llvm.org/show_bug.cgi?id=33820.

llvm-svn: 308239

lld/ELF/SymbolTable.cpp

@@ -211,13 +211,6 @@ static uint8_t getMinVisibility(uint8_t VA, uint8_t VB) {
 // 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;
@@ -724,13 +717,35 @@ void SymbolTable<ELFT>::assignWildcardVersion(SymbolVersion Ver,
       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);
+  }
+
   // Handle edge cases first.
   handleAnonymousVersion();
 
-
   // Now we have version definitions, so we need to set version ids to symbols.
   // Each version definition has a glob pattern, and all symbols that match
   // with the pattern get that version.

lld/test/ELF/Inputs/symver-archive1.s

@@ -1,6 +0,0 @@
-.text
-.globl x
-.type x, @function
-x:
-
-.symver x, xx@@VER

lld/test/ELF/Inputs/symver-archive2.s

@@ -1 +0,0 @@
-call xx@PLT

lld/test/ELF/symver-archive.s

@@ -1,15 +0,0 @@
-# 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