Description
Proposal
Currently, rustc writes output to files, even if options like -o - or --emit asm=- are specified. But sometimes it would be convenient if rustc writes text output (asm, dep-info, llvm-ir and mir) to stdout if the user explicitly asks for it, so that the output could be easily read or piped to consumer programs. For example I could write a simple name demangler and pipe the assembly output to it to make a poor man's command-line compiler explorer.
There are a few open issues where people proposed the same thing, like rust-lang/rust#47112 and rust-lang/rust#26719.
For gcc and clang, when -o - is provided, assembly output (produced via -S) will be written to stdout instead of a <source_file_name>.s file. Dependency information (produced via -MD) will still be written to a file called -.d. Preprocessor output (produced via -E) will always be written to stdout.
Mentors or Reviewers
I'm not sure who to include here.
Process
The main points of the Major Change Process are as follows:
- File an issue describing the proposal.
- A compiler team member or contributor who is knowledgeable in the area can second by writing
@rustbot second.- Finding a "second" suffices for internal changes. If however, you are proposing a new public-facing feature, such as a
-C flag, then full team check-off is required. - Compiler team members can initiate a check-off via
@rfcbot fcp mergeon either the MCP or the PR.
- Finding a "second" suffices for internal changes. If however, you are proposing a new public-facing feature, such as a
- Once an MCP is seconded, the Final Comment Period begins. If no objections are raised after 10 days, the MCP is considered approved.
You can read more about Major Change Proposals on forge.
Comments
This issue is not meant to be used for technical discussion. There is a Zulip stream for that. Use this issue to leave procedural comments, such as volunteering to review, indicating that you second the proposal (or third, etc), or raising a concern that you would like to be addressed.