ELF: Fix regression in TLS attribute mismatch logic.

Introduce a special symbol type to indicate that we have not yet seen a type
for the symbol, so we should not report TLS mismatches for that symbol.

Differential Revision: http://reviews.llvm.org/D19836

llvm-svn: 268411

3 files changed, 21 insertions, 3 deletions

diff --git a/lld/ELF/SymbolTable.cpp b/lld/ELF/SymbolTable.cpp
index 88747c7bb4c..852be823acb 100644
--- a/lld/ELF/SymbolTable.cpp
+++ b/lld/ELF/SymbolTable.cpp
@@ -209,7 +209,8 @@ SymbolTable<ELFT>::insert(StringRef Name, uint8_t Type, uint8_t Visibility,
     S->ExportDynamic = true;
   if (IsUsedInRegularObj)
     S->IsUsedInRegularObj = true;
-  if (!WasInserted && ((Type == STT_TLS) != S->body()->isTls()))
+  if (!WasInserted && S->body()->Type != SymbolBody::UnknownType &&
+      ((Type == STT_TLS) != S->body()->isTls()))
     error("TLS attribute mismatch for symbol: " +
           conflictMsg(S->body(), File));
 
@@ -436,7 +437,7 @@ void SymbolTable<ELFT>::addLazyArchive(
   bool WasInserted;
   std::tie(S, WasInserted) = insert(Sym.getName());
   if (WasInserted) {
-    replaceBody<LazyArchive>(S, F, Sym, STT_NOTYPE);
+    replaceBody<LazyArchive>(S, F, Sym, SymbolBody::UnknownType);
     return;
   }
   if (!S->body()->isUndefined())
@@ -464,7 +465,7 @@ void SymbolTable<ELFT>::addLazyObject(StringRef Name, MemoryBufferRef MBRef) {
   bool WasInserted;
   std::tie(S, WasInserted) = insert(Name);
   if (WasInserted) {
-    replaceBody<LazyObject>(S, Name, MBRef, STT_NOTYPE);
+    replaceBody<LazyObject>(S, Name, MBRef, SymbolBody::UnknownType);
     return;
   }
   if (!S->body()->isUndefined())
diff --git a/lld/ELF/Symbols.h b/lld/ELF/Symbols.h
index b66abb479f2..78b14a71bc1 100644
--- a/lld/ELF/Symbols.h
+++ b/lld/ELF/Symbols.h
@@ -131,6 +131,13 @@ public:
   uint8_t Type;    // symbol type
   uint8_t StOther; // st_other field value
 
+  // The Type field may also have this value. It means that we have not yet seen
+  // a non-Lazy symbol with this name, so we don't know what its type is. The
+  // Type field is normally set to this value for Lazy symbols unless we saw a
+  // weak undefined symbol first, in which case we need to remember the original
+  // symbol's type in order to check for TLS mismatches.
+  enum { UnknownType = 255 };
+
   bool isSection() const { return Type == llvm::ELF::STT_SECTION; }
   bool isTls() const { return Type == llvm::ELF::STT_TLS; }
   bool isFunc() const { return Type == llvm::ELF::STT_FUNC; }
diff --git a/lld/test/ELF/tls-archive.s b/lld/test/ELF/tls-archive.s
new file mode 100644
index 00000000000..5e7c825b063
--- /dev/null
+++ b/lld/test/ELF/tls-archive.s
@@ -0,0 +1,10 @@
+// REQUIRES: x86
+// RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t
+// RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %p/Inputs/tls-mismatch.s -o %t2
+// RUN: rm -f %t.a
+// RUN: llvm-ar cru %t.a %t2
+// RUN: ld.lld %t.a %t -o %t3
+
+.globl _start,tlsvar
+_start:
+  movl tlsvar@GOTTPOFF(%rip),%edx