builtin.h: take over documentation from api-builtin.txt

Delete Documentation/technical/api-builtin.txt and move its content into builtin.h. Format it as a comment. Remove a '+' which was needed when the information was formatted for AsciiDoc. Similarly, change "::" to ":". Document SUPPORT_SUPER_PREFIX, thereby bringing the documentation up to date with the available flags. While at it, correct '3 more things to do' to '4 more things to do'. Signed-off-by: Martin Ågren <martin.agren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Martin Ågren committed Aug 2, 2017 at 21:40 UTC ec14d4ecb5507550e31ba0a0016eb83fcde48f3f
2 files changed +80 -73
Documentation/technical/api-builtin.txt deleted
-73
@@ -1,73 +0,0 @@
1 -builtin API
2 -===========
3 -
4 -Adding a new built-in
5 ----------------------
6 -
7 -There are 4 things to do to add a built-in command implementation to
8 -Git:
9 -
10 -. Define the implementation of the built-in command `foo` with
11 - signature:
12 -
13 - int cmd_foo(int argc, const char **argv, const char *prefix);
14 -
15 -. Add the external declaration for the function to `builtin.h`.
16 -
17 -. Add the command to the `commands[]` table defined in `git.c`.
18 - The entry should look like:
19 -
20 - { "foo", cmd_foo, <options> },
21 -+
22 -where options is the bitwise-or of:
23 -
24 -`RUN_SETUP`::
25 - If there is not a Git directory to work on, abort. If there
26 - is a work tree, chdir to the top of it if the command was
27 - invoked in a subdirectory. If there is no work tree, no
28 - chdir() is done.
29 -
30 -`RUN_SETUP_GENTLY`::
31 - If there is a Git directory, chdir as per RUN_SETUP, otherwise,
32 - don't chdir anywhere.
33 -
34 -`USE_PAGER`::
35 -
36 - If the standard output is connected to a tty, spawn a pager and
37 - feed our output to it.
38 -
39 -`NEED_WORK_TREE`::
40 -
41 - Make sure there is a work tree, i.e. the command cannot act
42 - on bare repositories.
43 - This only makes sense when `RUN_SETUP` is also set.
44 -
45 -. Add `builtin/foo.o` to `BUILTIN_OBJS` in `Makefile`.
46 -
47 -Additionally, if `foo` is a new command, there are 3 more things to do:
48 -
49 -. Add tests to `t/` directory.
50 -
51 -. Write documentation in `Documentation/git-foo.txt`.
52 -
53 -. Add an entry for `git-foo` to `command-list.txt`.
54 -
55 -. Add an entry for `/git-foo` to `.gitignore`.
56 -
57 -
58 -How a built-in is called
59 -------------------------
60 -
61 -The implementation `cmd_foo()` takes three parameters, `argc`, `argv,
62 -and `prefix`. The first two are similar to what `main()` of a
63 -standalone command would be called with.
64 -
65 -When `RUN_SETUP` is specified in the `commands[]` table, and when you
66 -were started from a subdirectory of the work tree, `cmd_foo()` is called
67 -after chdir(2) to the top of the work tree, and `prefix` gets the path
68 -to the subdirectory the command started from. This allows you to
69 -convert a user-supplied pathname (typically relative to that directory)
70 -to a pathname relative to the top of the work tree.
71 -
72 -The return value from `cmd_foo()` becomes the exit status of the
73 -command.
builtin.h
+80
@@ -6,6 +6,86 @@
6 #include "cache.h"
7 #include "commit.h"
8
9 +/*
10 + * builtin API
11 + * ===========
12 + *
13 + * Adding a new built-in
14 + * ---------------------
15 + *
16 + * There are 4 things to do to add a built-in command implementation to
17 + * Git:
18 + *
19 + * . Define the implementation of the built-in command `foo` with
20 + * signature:
21 + *
22 + * int cmd_foo(int argc, const char **argv, const char *prefix);
23 + *
24 + * . Add the external declaration for the function to `builtin.h`.
25 + *
26 + * . Add the command to the `commands[]` table defined in `git.c`.
27 + * The entry should look like:
28 + *
29 + * { "foo", cmd_foo, <options> },
30 + *
31 + * where options is the bitwise-or of:
32 + *
33 + * `RUN_SETUP`:
34 + * If there is not a Git directory to work on, abort. If there
35 + * is a work tree, chdir to the top of it if the command was
36 + * invoked in a subdirectory. If there is no work tree, no
37 + * chdir() is done.
38 + *
39 + * `RUN_SETUP_GENTLY`:
40 + * If there is a Git directory, chdir as per RUN_SETUP, otherwise,
41 + * don't chdir anywhere.
42 + *
43 + * `USE_PAGER`:
44 + *
45 + * If the standard output is connected to a tty, spawn a pager and
46 + * feed our output to it.
47 + *
48 + * `NEED_WORK_TREE`:
49 + *
50 + * Make sure there is a work tree, i.e. the command cannot act
51 + * on bare repositories.
52 + * This only makes sense when `RUN_SETUP` is also set.
53 + *
54 + * `SUPPORT_SUPER_PREFIX`:
55 + *
56 + * The built-in supports `--super-prefix`.
57 + *
58 + * . Add `builtin/foo.o` to `BUILTIN_OBJS` in `Makefile`.
59 + *
60 + * Additionally, if `foo` is a new command, there are 4 more things to do:
61 + *
62 + * . Add tests to `t/` directory.
63 + *
64 + * . Write documentation in `Documentation/git-foo.txt`.
65 + *
66 + * . Add an entry for `git-foo` to `command-list.txt`.
67 + *
68 + * . Add an entry for `/git-foo` to `.gitignore`.
69 + *
70 + *
71 + * How a built-in is called
72 + * ------------------------
73 + *
74 + * The implementation `cmd_foo()` takes three parameters, `argc`, `argv,
75 + * and `prefix`. The first two are similar to what `main()` of a
76 + * standalone command would be called with.
77 + *
78 + * When `RUN_SETUP` is specified in the `commands[]` table, and when you
79 + * were started from a subdirectory of the work tree, `cmd_foo()` is called
80 + * after chdir(2) to the top of the work tree, and `prefix` gets the path
81 + * to the subdirectory the command started from. This allows you to
82 + * convert a user-supplied pathname (typically relative to that directory)
83 + * to a pathname relative to the top of the work tree.
84 + *
85 + * The return value from `cmd_foo()` becomes the exit status of the
86 + * command.
87 + */
88 +
89 #define DEFAULT_MERGE_LOG_LEN 20
90
91 extern const char git_usage_string[];