[LLVMdev] [llvm-commits] [PATCH] A "very verbose" mode for FileCheck

[Sean Silva]

On Thu, Jan 17, 2013 at 8:36 AM, Dmitri Gribenko <gribozavr at gmail.com> wrote:
> We have to options:
> (a) replace 'FileCheck' with '%FileCheck' in all tests, and teach
> 'lit' to replace '%FileCheck' with 'FileCheck --dump-input-on-error';
>
> (b) teach 'lit' to replace a plain 'FileCheck'.
>
> The first approach seems cleaner to developers who read and write
> tests (it suggests that they are invoking some "macro" -- but does
> that matter?)  The second approach is much easier to implement since
> tests will be unchanged.

IMO the biggest issue with (a) is that developers will continue to use
`FileCheck` instead of `%FileCheck`. So IMO (a) should only be
implemented if simultaneously there is a change that makes just plain
`FileCheck` an error.

Another approach would be to have a script or symlink
`FileCheck-dump-input-on-error` which lives in build/bin/ alongside
FileCheck, and which just invokes FileCheck in a way that causes it to
go into the "dump input on error" mode (e.g. it checks argv[0], or a
magic environment variable, or whatever). On the build bots,
FileCheck-dump-input-on-error and regular FileCheck could be swapped
by a configure option. That's kind of ugly, but some variation of it
may be more palatable.

-- Sean Silva