diff options
| author | Erik de Castro Lopo <erikd@mega-nerd.com> | 2016-10-22 15:38:41 -0400 |
|---|---|---|
| committer | Ben Gamari <ben@smart-cactus.org> | 2016-10-22 15:39:50 -0400 |
| commit | 3cb32d8b0b51c548ab424139c66cce6b37a2ab1b (patch) | |
| tree | 5602166b4af34666bcaad61a23cd5b216a971474 /docs/users_guide/using-warnings.rst | |
| parent | a662f46c32ce35bd0769aa1ab224c3dfd39e207c (diff) | |
| download | haskell-3cb32d8b0b51c548ab424139c66cce6b37a2ab1b.tar.gz | |
Add -Wcpp-undef warning flag
When enabled, this new warning flag passes `-Wundef` to the C
pre-processor which causes the pre-processor to warn on uses of
the `#if` directive on undefined identifiers.
It is not currently enabled in any of the standard warning groups.
Test Plan: Make sure the two tests pass on all major platforms.
Reviewers: hvr, carter, Phyx, bgamari, austin
Reviewed By: Phyx
Subscribers: thomie
Differential Revision: https://phabricator.haskell.org/D2626
GHC Trac Issues: #12752
Diffstat (limited to 'docs/users_guide/using-warnings.rst')
| -rw-r--r-- | docs/users_guide/using-warnings.rst | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/docs/users_guide/using-warnings.rst b/docs/users_guide/using-warnings.rst index c07058a4ef..c9216b9307 100644 --- a/docs/users_guide/using-warnings.rst +++ b/docs/users_guide/using-warnings.rst @@ -1007,6 +1007,12 @@ of ``-W(no-)*``. be inlined before the rule has a chance to fire. See :ref:`rules-inline`. +.. ghc-flag:: -Wcpp-undef + + This flag passes ``-Wundef`` to the C pre-processor (if its being used) + which causes the pre-processor to warn on uses of the `#if` directive on + undefined identifiers. + If you're feeling really paranoid, the :ghc-flag:`-dcore-lint` option is a good choice. It turns on heavyweight intra-pass sanity-checking within GHC. (It checks GHC's sanity, not yours.) |