Documentation / technical / api-setup.txton commit fetch-pack.c: use oidset to check existence of loose object (024aa46)
   1setup API
   2=========
   3
   4Talk about
   5
   6* setup_git_directory()
   7* setup_git_directory_gently()
   8* is_inside_git_dir()
   9* is_inside_work_tree()
  10* setup_work_tree()
  11
  12(Dscho)
  13
  14Pathspec
  15--------
  16
  17See glossary-context.txt for the syntax of pathspec. In memory, a
  18pathspec set is represented by "struct pathspec" and is prepared by
  19parse_pathspec(). This function takes several arguments:
  20
  21- magic_mask specifies what features that are NOT supported by the
  22  following code. If a user attempts to use such a feature,
  23  parse_pathspec() can reject it early.
  24
  25- flags specifies other things that the caller wants parse_pathspec to
  26  perform.
  27
  28- prefix and args come from cmd_* functions
  29
  30parse_pathspec() helps catch unsupported features and reject them
  31politely. At a lower level, different pathspec-related functions may
  32not support the same set of features. Such pathspec-sensitive
  33functions are guarded with GUARD_PATHSPEC(), which will die in an
  34unfriendly way when an unsupported feature is requested.
  35
  36The command designers are supposed to make sure that GUARD_PATHSPEC()
  37never dies. They have to make sure all unsupported features are caught
  38by parse_pathspec(), not by GUARD_PATHSPEC. grepping GUARD_PATHSPEC()
  39should give the designers all pathspec-sensitive codepaths and what
  40features they support.
  41
  42A similar process is applied when a new pathspec magic is added. The
  43designer lifts the GUARD_PATHSPEC restriction in the functions that
  44support the new magic. At the same time (s)he has to make sure this
  45new feature will be caught at parse_pathspec() in commands that cannot
  46handle the new magic in some cases. grepping parse_pathspec() should
  47help.