[gold] Enable MCTargetOptions::AsmVerbose along with emit-asm

[mshockwave]

Print comments into assembly output if we're using emit-asm.

[llvmbot]

@llvm/pr-subscribers-lto

Author: Min-Yih Hsu (mshockwave)

Changes

Use -plugin-opt=asm-verbose to print comments into assembly output.

---

Full diff: https://github.com/llvm/llvm-project/pull/71606.diff

2 Files Affected:

• (added) llvm/test/tools/gold/X86/asm-verbose.ll (+15)
• (modified) llvm/tools/gold/gold-plugin.cpp (+6)

diff --git a/llvm/test/tools/gold/X86/asm-verbose.ll b/llvm/test/tools/gold/X86/asm-verbose.ll
new file mode 100644
index 000000000000000..252d5b3a076d613
--- /dev/null
+++ b/llvm/test/tools/gold/X86/asm-verbose.ll
@@ -0,0 +1,15 @@
+; RUN: llvm-as -o %t.bc %s
+; RUN: %gold -plugin %llvmshlibdir/LLVMgold%shlibext -plugin-opt=emit-asm \
+; RUN:    -plugin-opt=asm-verbose \
+; RUN:    -m elf_x86_64 -r -o %t.s %t.bc
+; RUN: FileCheck --input-file=%t.s %s
+
+; Check if comments are emitted into assembly.
+; CHECK: -- End function
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define i32 @foo() {
+  ret i32 10
+}
diff --git a/llvm/tools/gold/gold-plugin.cpp b/llvm/tools/gold/gold-plugin.cpp
index d9e5983a4bacd63..bc4514990fa8f20 100644
--- a/llvm/tools/gold/gold-plugin.cpp
+++ b/llvm/tools/gold/gold-plugin.cpp
@@ -152,6 +152,7 @@ namespace options {
   static std::string extra_library_path;
   static std::string triple;
   static std::string mcpu;
+  static bool asm_verbose = false;
   // When the thinlto plugin option is specified, only read the function
   // the information from intermediate files and write a combined
   // global index for the ThinLTO backends.
@@ -308,6 +309,8 @@ namespace options {
       RemarksFormat = std::string(opt);
     } else if (opt.consume_front("stats-file=")) {
       stats_file = std::string(opt);
+    } else if (opt == "asm-verbose") {
+      asm_verbose = true;
     } else {
       // Save this option to pass to the code generator.
       // ParseCommandLineOptions() expects argv[0] to be program name. Lazily
@@ -950,6 +953,9 @@ static std::unique_ptr<LTO> createLTO(IndexWriteCallback OnIndexWrite,
   Conf.HasWholeProgramVisibility = options::whole_program_visibility;
 
   Conf.StatsFile = options::stats_file;
+
+  Conf.Options.MCOptions.AsmVerbose = options::asm_verbose;
+
   return std::make_unique<LTO>(std::move(Conf), Backend,
                                 options::ParallelCodeGenParallelismLevel);
 }

[teresajohnson]

I see that lld enables this unconditionally:

llvm-project/lld/ELF/LTO.cpp

Line 156 in 26ab444

c.Options.MCOptions.AsmVerbose = true;

How about just make it unconditionally true to be consistent and avoid adding another plugin option?

[teresajohnson]

I see that lld enables this unconditionally:

llvm-project/lld/ELF/LTO.cpp

Line 156 in 26ab444

c.Options.MCOptions.AsmVerbose = true;

How about just make it unconditionally true to be consistent and avoid adding another plugin option?

In which case you can just modify https://github.com/llvm/llvm-project/blob/26ab444e88fc8fdd554e5a9381a68b7b5e63b6fd/llvm/test/tools/gold/X86/emit-asm.ll slightly to check that the comments are emitted.

[mshockwave]

I see that lld enables this unconditionally:

llvm-project/lld/ELF/LTO.cpp

Line 156 in 26ab444

c.Options.MCOptions.AsmVerbose = true;

How about just make it unconditionally true to be consistent and avoid adding another plugin option?

In which case you can just modify https://github.com/llvm/llvm-project/blob/26ab444e88fc8fdd554e5a9381a68b7b5e63b6fd/llvm/test/tools/gold/X86/emit-asm.ll slightly to check that the comments are emitted.

Yes I think this is a good idea. I've updated the PR.