From 4aaeac6ad3e3bf8c33274b6daf67c1c0d917c5d1 Mon Sep 17 00:00:00 2001
From: Sean Silva <chisophugis@gmail.com>
Date: Wed, 9 Mar 2016 22:30:05 +0000
Subject: [PATCH] [lto] Add saving the LTO .o file to -save-temps.

Summary:
This implements another part of -save-temps.
After this, the only remaining part is dumping the optimized bitcode. But
currently LLD's LTO doesn't have a non-intrusive place to put this.
Eventually we probably will and it will make sense to add it then.

Reviewers: ruiu, rafael

Subscribers: joker.eph, Bigcheese, llvm-commits

Differential Revision: http://reviews.llvm.org/D18009

llvm-svn: 263070
---
 lld/ELF/SymbolTable.cpp        | 11 +++++++++++
 lld/test/ELF/lto/save-temps.ll |  7 ++++---
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/lld/ELF/SymbolTable.cpp b/lld/ELF/SymbolTable.cpp
index 9334f213054d..da8ed440d797 100644
--- a/lld/ELF/SymbolTable.cpp
+++ b/lld/ELF/SymbolTable.cpp
@@ -96,6 +96,15 @@ void SymbolTable<ELFT>::addFile(std::unique_ptr<InputFile> File) {
     resolve(B);
 }
 
+// This is for use when debugging LTO.
+static void saveLtoObjectFile(StringRef Buffer) {
+  std::error_code EC;
+  raw_fd_ostream OS(Config->OutputFile.str() + ".lto.o", EC,
+                    sys::fs::OpenFlags::F_None);
+  check(EC);
+  OS << Buffer;
+}
+
 // Codegen the module M and returns the resulting InputFile.
 template <class ELFT>
 std::unique_ptr<InputFile> SymbolTable<ELFT>::codegen(Module &M) {
@@ -123,6 +132,8 @@ std::unique_ptr<InputFile> SymbolTable<ELFT>::codegen(Module &M) {
     fatal("Failed to setup codegen");
   CodeGenPasses.run(M);
   LtoBuffer = MemoryBuffer::getMemBuffer(OwningLTOData, "", false);
+  if (Config->SaveTemps)
+    saveLtoObjectFile(LtoBuffer->getBuffer());
   return createObjectFile(*LtoBuffer);
 }
 
diff --git a/lld/test/ELF/lto/save-temps.ll b/lld/test/ELF/lto/save-temps.ll
index 54ffa0807a1d..2764095ff311 100644
--- a/lld/test/ELF/lto/save-temps.ll
+++ b/lld/test/ELF/lto/save-temps.ll
@@ -1,10 +1,11 @@
 ; REQUIRES: x86
-; RUN: rm -f %t.so %t.so.lto.bc
+; RUN: rm -f %t.so %t.so.lto.bc %t.so.lto.o
 ; RUN: llvm-as %s -o %t.o
 ; RUN: llvm-as %p/Inputs/save-temps.ll -o %t2.o
 ; RUN: ld.lld -shared -m elf_x86_64 %t.o %t2.o -o %t.so -save-temps
 ; RUN: llvm-nm %t.so | FileCheck %s
 ; RUN: llvm-nm %t.so.lto.bc | FileCheck %s
+; RUN: llvm-nm %t.so.lto.o | FileCheck %s
 
 target triple = "x86_64-unknown-linux-gnu"
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
@@ -13,5 +14,5 @@ define void @foo() {
   ret void
 }
 
-; CHECK-DAG: T bar
-; CHECK-DAG: T foo
+; CHECK: T bar
+; CHECK: T foo