[ELF] Error on archive with missing index

This matches the wasm lld and GNU ld behavior.

The ELF linker has special handling for bitcode archives but if that
doesn't kick in we probably want to error out rather than silently
ignore the library.

Differential Revision: https://reviews.llvm.org/D63781

llvm-svn: 364998

lld/ELF/Driver.cpp

@@ -223,8 +223,10 @@ void LinkerDriver::addFile(StringRef Path, bool WithLOption) {
       // default action without the LTO hack described above.
       for (const std::pair<MemoryBufferRef, uint64_t> &P :
            getArchiveMembers(MBRef))
-        if (identify_magic(P.first.getBuffer()) != file_magic::bitcode)
+        if (identify_magic(P.first.getBuffer()) != file_magic::bitcode) {
+          error(Path + ": archive has no index; run ranlib to add one");
           return;
+        }
 
       for (const std::pair<MemoryBufferRef, uint64_t> &P :
            getArchiveMembers(MBRef))

lld/test/ELF/archive-no-index.s

@@ -0,0 +1,13 @@
+# REQUIRES: x86
+# Tests error on archive file without a symbol table
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux -o %t.o %s
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux -o %t.archive.o %S/Inputs/archive.s
+# RUN: rm -f %t.a
+# RUN: llvm-ar crS %t.a %t.archive.o
+
+# RUN: not ld.lld -o out.wasm %t.o %t.a 2>&1 | FileCheck %s
+
+.globl _start
+_start:
+
+# CHECK: error: {{.*}}.a: archive has no index; run ranlib to add one

lld/test/ELF/lto/archive-no-index.ll

@@ -26,7 +26,7 @@ define i32 @main() {
 ; RUN: rm -f %t3.a
 ; RUN: llvm-ar crS %t3.a %t3.o
 ; RUN: not ld.lld -o /dev/null -emain %t1.o %t3.a 2>&1 | FileCheck -check-prefix=ERR1 %s
-; ERR1: error: undefined symbol: f
+; ERR1: error: {{.*}}.a: archive has no index; run ranlib to add one
 
 ; RUN: rm -f %t4.a
 ; RUN: llvm-ar cr %t4.a