[LTO] Don't crash on a BitcodeFile without DataLayout.

Emit an error instead.

llvm-svn: 266504

lld/ELF/LTO.cpp

@@ -82,6 +82,8 @@ void BitcodeCompiler::add(BitcodeFile &F) {
   ArrayRef<SymbolBody *> Bodies = F.getSymbols();
 
   Module &M = Obj->getModule();
+  if (M.getDataLayoutStr().empty())
+    fatal("invalid bitcode file: " + F.getName() + " has no datalayout");
 
   // If a symbol appears in @llvm.used, the linker is required
   // to treat the symbol as there is a reference to the symbol

lld/test/ELF/lto/invalid-bitcode.ll

@@ -0,0 +1,12 @@
+; REQUIRES: x86
+; RUN: llvm-as %s -o %t.o
+; RUN: not ld.lld -m elf_x86_64 %t.o 2>&1 | FileCheck %s
+
+; CHECK: invalid bitcode file:
+
+; This bitcode file has no datalayout.
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @_start() {
+  ret void
+}