calling rustc --parse-only only detects simple syntax errors

[Ghoughpteighbteau]

Warnings and logical errors are not detectable with this option.

Using syntastic 6c97353 (current as of writing)
VIM - Vi IMproved 7.4 (2013 Aug 10, compiled Aug 12 2013 00:23:33)
and rustc 0.9

some cursory work suggests that --no-trans would be more suitable than --parse-only. Though that's a complete guess, I don't know what the heck that option does 😅 but it does detect compile errors and show warnings

I have asked the devs for their opinion on this matter here: rust-lang/rust#3808

[lcd047]

--parse-only is just a default, the user can override it by setting g:syntastic_rust_rustc_args to something else. Are there any drawbacks to changing this default to --no-trans? That is, does --no-trans exist in all versions of rustc? Does it leave behind any temporary and / or output files? Does it make checking significantly slower than --parse-only? Does it need any extra libraries or modules to be installed? Is the output more useful than the output of --parse-only in all possible cases?

[Ghoughpteighbteau]

rust-lang/rust#3808 agrees with me on this one

--no-trans is the best current option (we might be missing some higher level analysis on this one, but it's vastly superior to --parse-only)

I have no idea regarding performance, unfortunately performance is just not a consideration when the default produces such a shallow level of reporting, that option just isn't doing the job.

the --no-trans option has existed since rust 0.1 So compatibility isn't an issue.

--no-trans produces no output or temporary files. It's part of rust compiler, and the output is a superset of the errors --parse-only can produce.

[lcd047]

Ok, you break it, you get to keep both parts. :) Changed in a39b397.