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Diffstat (limited to 'docs/users_guide/debugging.rst')
| -rw-r--r-- | docs/users_guide/debugging.rst | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/docs/users_guide/debugging.rst b/docs/users_guide/debugging.rst index efa6e2808d..399791925c 100644 --- a/docs/users_guide/debugging.rst +++ b/docs/users_guide/debugging.rst @@ -270,6 +270,19 @@ subexpression elimination pass. Dumps detailed information about all rules that fired in this module +.. ghc-flag:: -drule-check=⟨str⟩ + :shortdesc: Dump information about potential rule application + :type: dynamic + + This flag is useful for debugging why a rule you expect to be firing isn't. + + Rules are filtered by the user provided string, a rule is kept if a prefix + of its name matches the string. + The pass then checks whether any of these rules could apply to + the program but which didn't file for some reason. For example, specifying + ``-drule-check=SPEC`` will check whether there are any applications which + might be subject to a rule created by specialisation. + .. ghc-flag:: -ddump-vect :shortdesc: Dump vectoriser input and output :type: dynamic |