path: root/Documentation
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Diffstat (limited to 'Documentation')
1 files changed, 19 insertions, 0 deletions
diff --git a/Documentation/technical/api-setup.txt b/Documentation/technical/api-setup.txt
index 90d1aff..540e455 100644
--- a/Documentation/technical/api-setup.txt
+++ b/Documentation/technical/api-setup.txt
@@ -28,3 +28,22 @@ parse_pathspec(). This function takes several arguments:
- prefix and args come from cmd_* functions
get_pathspec() is obsolete and should never be used in new code.
+parse_pathspec() helps catch unsupported features and reject them
+politely. At a lower level, different pathspec-related functions may
+not support the same set of features. Such pathspec-sensitive
+functions are guarded with GUARD_PATHSPEC(), which will die in an
+unfriendly way when an unsupported feature is requested.
+The command designers are supposed to make sure that GUARD_PATHSPEC()
+never dies. They have to make sure all unsupported features are caught
+by parse_pathspec(), not by GUARD_PATHSPEC. grepping GUARD_PATHSPEC()
+should give the designers all pathspec-sensitive codepaths and what
+features they support.
+A similar process is applied when a new pathspec magic is added. The
+designer lifts the GUARD_PATHSPEC restriction in the functions that
+support the new magic. At the same time (s)he has to make sure this
+new feature will be caught at parse_pathspec() in commands that cannot
+handle the new magic in some cases. grepping parse_pathspec() should