Use warn() instead of error() to report a bad symbol in a DSO.

[ruiu]

Summary

Specifically, libwidevinecdm.so in Chrome has such bad symbol.

[ruiu]

• Instead of adding a bad symbol to the symbol table, skip it.

[pcc]

LGTM

lld/test/ELF/invalid-local-symbol-in-dso.s

4

Can we also test that we fail to link against the symbol?

[pcc]

lld/trunk/test/ELF/invalid-local-symbol-in-dso.s

4 ↗

(On Diff #127039)

Do you need to create an object file? Can you just pass the .so file?

lld/ELF/InputFiles.cpp

for (const Elf_Sym &Sym : Syms) {
     VersymIndex = VersymIndex & ~VERSYM_HIDDEN;
 
     StringRef Name = CHECK(Sym.getName(this->StringTable), this);
     if (Sym.isUndefined()) {
       Undefs.push_back(Name);
       continue;
     }
 
+    if (Sym.getBinding() == STB_LOCAL) {
+      warn("Found local symbol '" + Name +
+           "' in global part of symbol table in file " + toString(this));
+      continue;
+    }
+
     // Ignore local symbols.
     if (Versym && VersymIndex == VER_NDX_LOCAL)
       continue;
     const Elf_Verdef *Ver = nullptr;
     if (VersymIndex != VER_NDX_GLOBAL) {
       if (VersymIndex >= Verdefs.size()) {
         error("corrupt input file: version definition index " +
               Twine(VersymIndex) + " for symbol " + Name +

lld/ELF/SymbolTable.cpp

void SymbolTable::addShared(StringRef Name, SharedFile<ELFT> *File,
   if (Sym.getVisibility() == STV_DEFAULT)
     S->ExportDynamic = true;
 
   // An undefined symbol with non default visibility must be satisfied
   // in the same DSO.
   if (WasInserted || ((S->isUndefined() || S->isLazy()) &&
                       S->getVisibility() == STV_DEFAULT)) {
     uint8_t Binding = S->Binding;
-    uint8_t OrigBinding = Sym.getBinding();
-    if (OrigBinding == STB_LOCAL)
-      error("Found local symbol '" + Name +
-            "' in global part of symbol table in file " + toString(File));
-    replaceSymbol<SharedSymbol>(S, File, Name, OrigBinding, Sym.st_other,
+    replaceSymbol<SharedSymbol>(S, File, Name, Sym.getBinding(), Sym.st_other,
                                 Sym.getType(), Sym.st_value, Sym.st_size,
                                 Alignment, VerdefIndex);
     if (!WasInserted) {
       S->Binding = Binding;
       if (!S->isWeak() && !Config->GcSections)
         File->IsNeeded = true;
     }
   }

lld/test/ELF/invalid-local-symbol-in-dso.s

 # RUN: llvm-mc %s -o %t.o -filetype=obj -triple x86_64-pc-linux
 
 # We used to crash on this
-# RUN: not ld.lld %t.o %p/Inputs/local-symbol-in-dso.so -o %t 2>&1 | FileCheck %s
+# RUN: ld.lld %t.o %p/Inputs/local-symbol-in-dso.so -o %t 2>&1 | FileCheck %s
 # CHECK: Found local symbol 'foo' in global part of symbol table in file {{.*}}local-symbol-in-dso.so