Index: llvm/include/llvm-c/lto.h
===================================================================
--- llvm/include/llvm-c/lto.h
+++ llvm/include/llvm-c/lto.h
@@ -548,6 +548,11 @@
                                             const char *const *, int number);
 
 /**
+ * Sets the result filetype to assembly.
+ */
+extern void lto_codegen_emit_asm(lto_code_gen_t cg);
+
+/**
  * Initializes LLVM disassemblers.
  * FIXME: This doesn't really belong here.
  *
Index: llvm/tools/lto/lto.cpp
===================================================================
--- llvm/tools/lto/lto.cpp
+++ llvm/tools/lto/lto.cpp
@@ -490,6 +490,10 @@
   unwrap(cg)->setCodeGenDebugOptions(makeArrayRef(Options));
 }
 
+void lto_codegen_emit_asm(lto_code_gen_t cg) {
+  unwrap(cg)->setFileType(CGFT_AssemblyFile);
+}
+
 unsigned int lto_api_version() { return LTO_API_VERSION; }
 
 void lto_codegen_set_should_internalize(lto_code_gen_t cg,
Index: llvm/tools/lto/lto.exports
===================================================================
--- llvm/tools/lto/lto.exports
+++ llvm/tools/lto/lto.exports
@@ -35,6 +35,7 @@
 lto_codegen_write_merged_modules
 lto_codegen_debug_options
 lto_codegen_debug_options_array
+lto_codegen_emit_asm
 lto_codegen_set_assembler_args
 lto_codegen_set_assembler_path
 lto_codegen_set_cpu