[LTO] Add ability to emit assembly to new LTO API

Summary:
Add a field to LTO::Config, CGFileType, to select the file type to emit (object
or assembly). This is useful for testing and to implement -save-temps.

Reviewers: tejohnson, mehdi_amini, pcc

Reviewed By: mehdi_amini

Subscribers: davide, llvm-commits

Differential Revision: https://reviews.llvm.org/D29475

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@295226 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/LTO/Config.h

@@ -17,6 +17,7 @@
 
 #include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/Support/CodeGen.h"
+#include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetOptions.h"
 
 #include <functional>
@@ -41,6 +42,7 @@ struct Config {
   Reloc::Model RelocModel = Reloc::PIC_;
   CodeModel::Model CodeModel = CodeModel::Default;
   CodeGenOpt::Level CGOptLevel = CodeGenOpt::Default;
+  TargetMachine::CodeGenFileType CGFileType = TargetMachine::CGFT_ObjectFile;
   unsigned OptLevel = 2;
   bool DisableVerify = false;
 

lib/LTO/LTO.cpp

@@ -98,6 +98,7 @@ static void computeCacheKey(
   AddUnsigned(Conf.RelocModel);
   AddUnsigned(Conf.CodeModel);
   AddUnsigned(Conf.CGOptLevel);
+  AddUnsigned(Conf.CGFileType);
   AddUnsigned(Conf.OptLevel);
   AddString(Conf.OptPipeline);
   AddString(Conf.AAPipeline);

lib/LTO/LTOBackend.cpp

@@ -271,8 +271,7 @@ void codegen(Config &Conf, TargetMachine *TM, AddStreamFn AddStream,
 
   auto Stream = AddStream(Task);
   legacy::PassManager CodeGenPasses;
-  if (TM->addPassesToEmitFile(CodeGenPasses, *Stream->OS,
-                              TargetMachine::CGFT_ObjectFile))
+  if (TM->addPassesToEmitFile(CodeGenPasses, *Stream->OS, Conf.CGFileType))
     report_fatal_error("Failed to setup codegen");
   CodeGenPasses.run(Mod);
 }

test/LTO/Resolution/X86/asm-output.ll

@@ -0,0 +1,19 @@
+; Test the ability to emit assembly code from the resolution-based LTO API
+;
+; RUN: llvm-as < %s > %t1.bc
+;
+; RUN: llvm-lto2 -filetype=asm -r %t1.bc,main,px -o %t2 %t1.bc
+; RUN: FileCheck --check-prefix=ASM %s < %t2.0
+; RUN: llvm-lto2 -filetype=obj -r %t1.bc,main,px -o %t2 %t1.bc
+; RUN: llvm-objdump -d %t2.0 | FileCheck --check-prefix=ASM %s
+;
+; ASM: main:
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define i32 @main() {
+entry:
+  ret i32 23
+}
+

tools/llvm-lto2/llvm-lto2.cpp

@@ -212,6 +212,9 @@ int main(int argc, char **argv) {
     return 1;
   }
 
+  if (FileType.getNumOccurrences())
+    Conf.CGFileType = FileType;
+
   Conf.OverrideTriple = OverrideTriple;
   Conf.DefaultTriple = DefaultTriple;