Fix handling of files without a symbol table.

This fixes a recent regression (r183338). Stripped elf files (like installed
crtn.o for example), are not required to have a symbol table. Handle that
correctly.

llvm-svn: 183573

3 files changed, 8 insertions, 1 deletions

diff --git a/lld/lib/ReaderWriter/ELF/File.h b/lld/lib/ReaderWriter/ELF/File.h
index 720e67eb129..c732bef18a9 100644
--- a/lld/lib/ReaderWriter/ELF/File.h
+++ b/lld/lib/ReaderWriter/ELF/File.h
@@ -279,7 +279,11 @@ public:
     llvm::object::symbol_iterator it(_objFile->begin_symbols());
     llvm::object::symbol_iterator ie(_objFile->end_symbols());
 
-    for (it.increment(EC); it != ie; it.increment(EC)) {
+    // Skip ELF's first dummy symbol if we have one.
+    if (it != ie)
+      it.increment(EC);
+
+    for (; it != ie; it.increment(EC)) {
       if (EC)
         return true;
 
diff --git a/lld/test/elf/Inputs/stripped-empty.x86_64 b/lld/test/elf/Inputs/stripped-empty.x86_64
new file mode 100644
index 00000000000..7368ba280d7
--- /dev/null
+++ b/lld/test/elf/Inputs/stripped-empty.x86_64
diff --git a/lld/test/elf/stripped-empty.test b/lld/test/elf/stripped-empty.test
new file mode 100644
index 00000000000..1794161291c
--- /dev/null
+++ b/lld/test/elf/stripped-empty.test
@@ -0,0 +1,3 @@
+RUN: lld -flavor gnu -shared -o test.so %p/Inputs/stripped-empty.x86_64
+
+test that we handle files without a symbol table.