Fix crash on invalid

[ruiu]

LGTM. Thanks!

[hans]

This fixes the assert, now we error on it, which breaks our build all the same. It's a pre-built .so, which I'm not sure exactly where it comes from:

FAILED: libwidevinecdmadapter.so
../../../../../../../../work/llvm/build.goma/bin/clang++ -shared libwidevinecdm.so -Wl,--fatal-warnings -Wl,--build-id=sha1 -fPIC -Wl,-z,noexecstack -Wl,-z,now -Wl,-z,relro -Wl,-z,defs -Wl,--no-as-needed -lpthread -Wl,--as-needed -fuse-ld=lld -Wl,--icf=all -flto=thin -Wl,--thinlto-jobs=8 -Wl,--thinlto-cache-dir=thinlto-cache -Wl,--thinlto-cache-policy,cache_size=10\% -Wl,--lto-O0 -fwhole-program-vtables -m64 -Werror -Wl,-O1 -Wl,--gc-sections -Wl,--gdb-index -nostdlib++ --sysroot=../../build/linux/debian_stretch_amd64-sysroot -L../../build/linux/debian_stretch_amd64-sysroot/lib/x86_64-linux-gnu -Wl,-rpath-link=../../build/linux/debian_stretch_amd64-sysroot/lib/x86_64-linux-gnu -L../../build/linux/debian_stretch_amd64-sysroot/usr/lib/x86_64-linux-gnu -Wl,-rpath-link=../../build/linux/debian_stretch_amd64-sysroot/usr/lib/x86_64-linux-gnu -fsanitize=cfi-vcall -Wl,-rpath=\$ORIGIN/. -Wl,-rpath-link=. -o "./libwidevinecdmadapter.so" -Wl,-soname="libwidevinecdmadapter.so" @"./libwidevinecdmadapter.so.rsp"
/usr/local/google/work/chromium/src/out/release/../../../../../../../../work/llvm/build.goma/bin/ld.lld: error: Found local symbol '_ZN8tcmalloc11ThreadCache17threadlocal_heap_E' in global part of symbol table in file libwidevinecdm.so
clang-6.0: error: linker command failed with exit code 1 (use -v to see invocation)
ninja: build stopped: subcommand failed.

Maybe the erorr could be downgraded to a warning? (We'd need to not treat warnings as errors for this target on our side I suppose)

[hans]

Can we revert r319127 until this is fixed?

This blocks Chromium from updating LLVM.

[hans]

pcc: Do you have any input on how we can fix this?

[• espindola]

r320667

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;
-    replaceSymbol<SharedSymbol>(S, File, Name, Sym.getBinding(), Sym.st_other,
+    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,
                                 Sym.getType(), Sym.st_value, Sym.st_size,
                                 Alignment, VerdefIndex);
     if (!WasInserted) {
       S->Binding = Binding;
       if (!S->isWeak() && !Config->GcSections)
         File->IsNeeded = true;
     }
   }

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
+# CHECK: Found local symbol 'foo' in global part of symbol table in file {{.*}}local-symbol-in-dso.so