-Z dump-mir usage instructions not clear

[vext01]

Hi,

I wanted to inspect the MIR of my program and found -Z dump-mir via this issue:
rust-lang/rustc-dev-guide#11

The usage for this option is:

$ rustc -Z help
...
    -Z       dump-mir=val -- dump MIR state at various points in transforms
...

What can val be here? I've managed to figure out that -Z dump-mir=all works, but what else is valid? I think the usage string should say.

Thanks

[wesleywiser]

For reference, the rustc guide has additional information on this flag that could either be adapted for the help info or, at least, linked to.

[vext01]

How about something like:

-Z                       dump-mir=val -- dump MIR state to file
    'val' is used to select which passes and functions to dump. For example:
     - 'all' matches all passes and functions.
     - 'foo' all passes for functions whose name contains 'foo'.
     - 'foo & CleanEndRegions' Only the 'CleanEndRegions' pass for function names containing 'foo'.
     - 'foo | bar' all passes for function names containing 'foo' or 'bar'.

Too long?

[wesleywiser]

Seems like nearly all of the existing options are one-line. There's one notable exception:

    -Z                       unpretty=val -- Present the input source, unstable (and less-pretty) variants;
        valid types are any of the types for `--pretty`, as well as:
        `flowgraph=<nodeid>` (graphviz formatted flowgraph for node),
        `everybody_loops` (all function bodies replaced with `loop {}`),
        `hir` (the HIR), `hir,identified`, or
        `hir,typed` (HIR with types for each node).

So I guess there's precedent?

[vext01]

Indeed. That's where I copied the indentation style from.

[vext01]

(Should perhaps drop the hyphens and use backticks though)

[wesleywiser]

That sounds good to me 😃

[matthewjasper]

CleanEndRegions should be replaced with a pass that still exists. (See rustc_mir::transform for the passes that's rustc currently has)

[vext01]

Great. I'll raise a PR for this shortlyish.

[vext01]

PR for this is now up.

[Ryvian]

Is there any way to dump only the ordinary MIR file (like rustc.main.003-027.PreCodegen.after.mir) without producing any promoted MIR files (like rustc.main-promoted[1].003-027.PreCodegen.after.mir)?