How to generate godbolt like clean assembly locally?

Question

I want to generate clean assembly like Compiler Explorer locally. Note that, I read How to remove “noise” from GCC/clang assembly output? before attempting this. The output using that method isn't as clean or dense compared to godbolt and still has a lot of asm directives and unused labels in it.

How can I get clean assembly output without any unused labels or directives?

Answer 1

I checked Compiler Explorer to see if they had a specific set of compiler options to get their output. But they don't. Instead they filter the assembly listing with this function. There's also an additional processing step that merges the debug info into source and assembly highlighting.

To answer your question, I don't think it's possible with GCC itself right now (Sep 2021).

Answer 2

For the record, it is possible (and apparently not too hard) to set up a local install of Matt Godbolt's Compiler Explorer stuff, so you can use that to explore asm output for files that are part of existing large projects with their #include dependencies and everything.

If you already have some asm output, @Waqar's answer looks useful. Or maybe that functionality can be used on its own from the Compiler Explorer repo via node.js, IDK.

According to the install info in the readme in https://github.com/compiler-explorer/compiler-explorer (Matt's repo), you can simply run make after cloning it on a machine that has node.js installed.

---

I also found https://isocpp.org/blog/2017/10/cpp-weekly-episode-83-installing-compiler-explorerjason-turner which might have more details (or be obsolete at this point, IDK).

I think Matt also mentions using a local clone of Compiler Explorer in his CppCon 2017 talk about Compiler Explorer (maybe replying to a question at the end), “What Has My Compiler Done for Me Lately? Unbolting the Compiler's Lid”, and recommends it for playing with code that uses lots of #include that would be hard to get onto https://godbolt.org/. (Or for closed-source code).