Documentation for assembly output format from "emcc -S"?

[gregbuchholz]

I'm wondering where I can find the documentation describing the assembly output format used for the files generated by using the "-S" format to emcc. For instance, if you take example.c and run emcc example.c -S -pthread, you get this output file: example.s. Obviously the assembly instructions are web-assembly, but I'm interested in learning more about what the "T" and @ represent in a directive like:

.section .tdata.variable1,"T",@

..etc.

Thanks!

[sbc100]

This is the assembly format that is output by llvm (and read by llvm). I'm afraid there is no good documentation for this specific format but it shares a lot with standard GNU assembly format used by llvm on other platforms. For example the "T" there means that section is thread local (TLS).

See https://ftp.gnu.org/old-gnu/Manuals/gas-2.9.1/html_chapter/as_7.html (although I notice that "T" is not listed amount that flags there :).

[gregbuchholz]

Thanks for the info.

[sbc100]

Is there some reason you are interested in this format? Do you have plans to author files directly in assembler perhaps?

[gregbuchholz]

My interest just comes from as part of a debugging exercise to try and identify the source of the problem outlined here. I do not have any plans on authoring wasm files in this format.