Fix a bogus warning

[• rafael]

Summary

We first decide that the symbol is global, than that it should have version foo. Since it was already not the default version, we were producing a bogus warning.

[pcc]

LGTM

[• espindola]

289284

ELF/SymbolTable.cpp

std::pair<Symbol *, bool> SymbolTable<ELFT>::insert(StringRef Name) {
   if (V.Idx == -1) {
     IsNew = true;
     V = SymIndex((int)SymVector.size(), true);
   }
 
   Symbol *Sym;
   if (IsNew) {
     Sym = new (BAlloc) Symbol;
+    Sym->InVersionScript = false;
     Sym->Binding = STB_WEAK;
     Sym->Visibility = STV_DEFAULT;
     Sym->IsUsedInRegularObj = false;
     Sym->ExportDynamic = false;
     Sym->Traced = V.Traced;
     Sym->VersionId = Config->DefaultSymbolVersion;
     SymVector.push_back(Sym);
   } else {
void SymbolTable<ELFT>::assignExactVersion(SymbolVersion Ver, uint16_t VersionId,
   for (SymbolBody *B : Syms) {
     if (!B || B->isUndefined()) {
       if (Config->NoUndefinedVersion)
         error("version script assignment of '" + VersionName + "' to symbol '" +
               Ver.Name + "' failed: symbol not defined");
       continue;
     }
 
-    if (B->symbol()->VersionId != Config->DefaultSymbolVersion)
+    Symbol *Sym = B->symbol();
+    if (Sym->InVersionScript)
       warn("duplicate symbol '" + Ver.Name + "' in version script");
-    B->symbol()->VersionId = VersionId;
+    Sym->VersionId = VersionId;
+    Sym->InVersionScript = true;
   }
 }
 
 template <class ELFT>
 void SymbolTable<ELFT>::assignWildcardVersion(SymbolVersion Ver,
                                               uint16_t VersionId) {
   if (!Ver.HasWildcard)
     return;

ELF/Symbols.h

struct Symbol {
   // will appear in .dynsym. This flag is set by interposable DSO symbols in
   // executables, by most symbols in DSOs and executables built with
   // --export-dynamic, and by dynamic lists.
   unsigned ExportDynamic : 1;
 
   // True if this symbol is specified by --trace-symbol option.
   unsigned Traced : 1;
 
+  // This symbol version was found in a version script.
+  unsigned InVersionScript : 1;
+
   bool includeInDynsym() const;
   bool isWeak() const { return Binding == llvm::ELF::STB_WEAK; }
 
   // This field is used to store the Symbol's SymbolBody. This instantiation of
   // AlignedCharArrayUnion gives us a struct with a char array field that is
   // large and aligned enough to store any derived class of SymbolBody. We
   // assume that the size and alignment of ELF64LE symbols is sufficient for any
   // ELFT, and we verify this with the static_asserts in replaceBody.

test/ELF/version-script-no-warn.s

+# REQUIRES: x86
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %p/Inputs/shared.s -o %t2.o
+# RUN: ld.lld -shared %t2.o -soname shared -o %t2.so
+
+# RUN: echo "foo { global: bar;  local: *; };" > %t.script
+# RUN: ld.lld --fatal-warnings --shared --version-script %t.script %t.o %t2.so
+
+.global bar
+bar:
+        nop