trailer: execute command from 'trailer.<name>.command'

Let the user specify a command that will give on its standard output
the value to use for the specified trailer.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/trailer.c b/trailer.c
index b0be0d7c5ca66d099307f7f217e7c5a6d3c18111..85145665640d3569b5513c712335da4de21743d3 100644 (file)
--- a/trailer.c
+++ b/trailer.c
@@ -1,5 +1,7 @@
 #include "cache.h"
 #include "string-list.h"
 #include "cache.h"
 #include "string-list.h"

+#include "run-command.h"
+#include "string-list.h"

 #include "trailer.h"
 /*
  * Copyright (c) 2013, 2014 Christian Couder <chriscool@tuxfamily.org>
 #include "trailer.h"
 /*
  * Copyright (c) 2013, 2014 Christian Couder <chriscool@tuxfamily.org>


@@ -33,6 +35,8 @@ static struct trailer_item *first_conf_item;
 
 static char *separators = ":";
 
 
 static char *separators = ":";
 

+#define TRAILER_ARG_STRING "$ARG"
+

 static int after_or_end(enum action_where where)
 {
        return (where == WHERE_AFTER) || (where == WHERE_END);
 static int after_or_end(enum action_where where)
 {
        return (where == WHERE_AFTER) || (where == WHERE_END);


@@ -78,6 +82,13 @@ static inline int contains_only_spaces(const char *str)
        return !*s;
 }
 
        return !*s;
 }
 

+static inline void strbuf_replace(struct strbuf *sb, const char *a, const char *b)
+{
+       const char *ptr = strstr(sb->buf, a);
+       if (ptr)
+               strbuf_splice(sb, ptr - sb->buf, strlen(a), b, strlen(b));
+}
+

 static void free_trailer_item(struct trailer_item *item)
 {
        free(item->conf.name);
 static void free_trailer_item(struct trailer_item *item)
 {
        free(item->conf.name);


@@ -203,6 +214,63 @@ static struct trailer_item *remove_first(struct trailer_item **first)
        return item;
 }
 
        return item;
 }
 

+static int read_from_command(struct child_process *cp, struct strbuf *buf)
+{
+       if (run_command(cp))
+               return error("running trailer command '%s' failed", cp->argv[0]);
+       if (strbuf_read(buf, cp->out, 1024) < 1)
+               return error("reading from trailer command '%s' failed", cp->argv[0]);
+       strbuf_trim(buf);
+       return 0;
+}
+
+static const char *apply_command(const char *command, const char *arg)
+{
+       struct strbuf cmd = STRBUF_INIT;
+       struct strbuf buf = STRBUF_INIT;
+       struct child_process cp;
+       const char *argv[] = {NULL, NULL};
+       const char *result;
+
+       strbuf_addstr(&cmd, command);
+       if (arg)
+               strbuf_replace(&cmd, TRAILER_ARG_STRING, arg);
+
+       argv[0] = cmd.buf;
+       memset(&cp, 0, sizeof(cp));
+       cp.argv = argv;
+       cp.env = local_repo_env;
+       cp.no_stdin = 1;
+       cp.out = -1;
+       cp.use_shell = 1;
+
+       if (read_from_command(&cp, &buf)) {
+               strbuf_release(&buf);
+               result = xstrdup("");
+       } else
+               result = strbuf_detach(&buf, NULL);
+
+       strbuf_release(&cmd);
+       return result;
+}
+
+static void apply_item_command(struct trailer_item *in_tok, struct trailer_item *arg_tok)
+{
+       if (arg_tok->conf.command) {
+               const char *arg;
+               if (arg_tok->value && arg_tok->value[0]) {
+                       arg = arg_tok->value;
+               } else {
+                       if (in_tok && in_tok->value)
+                               arg = xstrdup(in_tok->value);
+                       else
+                               arg = xstrdup("");
+               }
+               arg_tok->value = apply_command(arg_tok->conf.command, arg);
+               free((char *)arg);
+       }
+}
+

 static void apply_arg_if_exists(struct trailer_item *in_tok,
                                struct trailer_item *arg_tok,
                                struct trailer_item *on_tok,
 static void apply_arg_if_exists(struct trailer_item *in_tok,
                                struct trailer_item *arg_tok,
                                struct trailer_item *on_tok,


@@ -214,16 +282,19 @@ static void apply_arg_if_exists(struct trailer_item *in_tok,
                free_trailer_item(arg_tok);
                break;
        case EXISTS_REPLACE:
                free_trailer_item(arg_tok);
                break;
        case EXISTS_REPLACE:

+               apply_item_command(in_tok, arg_tok);

                add_arg_to_input_list(on_tok, arg_tok,
                                      in_tok_first, in_tok_last);
                remove_from_list(in_tok, in_tok_first, in_tok_last);
                free_trailer_item(in_tok);
                break;
        case EXISTS_ADD:
                add_arg_to_input_list(on_tok, arg_tok,
                                      in_tok_first, in_tok_last);
                remove_from_list(in_tok, in_tok_first, in_tok_last);
                free_trailer_item(in_tok);
                break;
        case EXISTS_ADD:

+               apply_item_command(in_tok, arg_tok);

                add_arg_to_input_list(on_tok, arg_tok,
                                      in_tok_first, in_tok_last);
                break;
        case EXISTS_ADD_IF_DIFFERENT:
                add_arg_to_input_list(on_tok, arg_tok,
                                      in_tok_first, in_tok_last);
                break;
        case EXISTS_ADD_IF_DIFFERENT:

+               apply_item_command(in_tok, arg_tok);

                if (check_if_different(in_tok, arg_tok, 1))
                        add_arg_to_input_list(on_tok, arg_tok,
                                              in_tok_first, in_tok_last);
                if (check_if_different(in_tok, arg_tok, 1))
                        add_arg_to_input_list(on_tok, arg_tok,
                                              in_tok_first, in_tok_last);


@@ -231,6 +302,7 @@ static void apply_arg_if_exists(struct trailer_item *in_tok,
                        free_trailer_item(arg_tok);
                break;
        case EXISTS_ADD_IF_DIFFERENT_NEIGHBOR:
                        free_trailer_item(arg_tok);
                break;
        case EXISTS_ADD_IF_DIFFERENT_NEIGHBOR:

+               apply_item_command(in_tok, arg_tok);

                if (check_if_different(on_tok, arg_tok, 0))
                        add_arg_to_input_list(on_tok, arg_tok,
                                              in_tok_first, in_tok_last);
                if (check_if_different(on_tok, arg_tok, 0))
                        add_arg_to_input_list(on_tok, arg_tok,
                                              in_tok_first, in_tok_last);


@@ -254,6 +326,7 @@ static void apply_arg_if_missing(struct trailer_item **in_tok_first,
        case MISSING_ADD:
                where = arg_tok->conf.where;
                in_tok = after_or_end(where) ? in_tok_last : in_tok_first;
        case MISSING_ADD:
                where = arg_tok->conf.where;
                in_tok = after_or_end(where) ? in_tok_last : in_tok_first;

+               apply_item_command(NULL, arg_tok);

                if (*in_tok) {
                        add_arg_to_input_list(*in_tok, arg_tok,
                                              in_tok_first, in_tok_last);
                if (*in_tok) {
                        add_arg_to_input_list(*in_tok, arg_tok,
                                              in_tok_first, in_tok_last);


@@ -537,7 +610,7 @@ static struct trailer_item *new_trailer_item(struct trailer_item *conf_item,
                                             char *tok, char *val)
 {
        struct trailer_item *new = xcalloc(sizeof(*new), 1);
                                             char *tok, char *val)
 {
        struct trailer_item *new = xcalloc(sizeof(*new), 1);

-       new->value = val;
+       new->value = val ? val : xstrdup("");

 
        if (conf_item) {
                duplicate_conf(&new->conf, &conf_item->conf);
 
        if (conf_item) {
                duplicate_conf(&new->conf, &conf_item->conf);


@@ -604,7 +677,17 @@ static struct trailer_item *process_command_line_args(struct string_list *traile
        struct trailer_item *arg_tok_first = NULL;
        struct trailer_item *arg_tok_last = NULL;
        struct string_list_item *tr;
        struct trailer_item *arg_tok_first = NULL;
        struct trailer_item *arg_tok_last = NULL;
        struct string_list_item *tr;

+       struct trailer_item *item;
+
+       /* Add a trailer item for each configured trailer with a command */
+       for (item = first_conf_item; item; item = item->next) {
+               if (item->conf.command) {
+                       struct trailer_item *new = new_trailer_item(item, NULL, NULL);
+                       add_trailer_item(&arg_tok_first, &arg_tok_last, new);
+               }
+       }

 
 

+       /* Add a trailer item for each trailer on the command line */

        for_each_string_list_item(tr, trailers) {
                struct trailer_item *new = create_trailer_item(tr->string);
                add_trailer_item(&arg_tok_first, &arg_tok_last, new);
        for_each_string_list_item(tr, trailers) {
                struct trailer_item *new = create_trailer_item(tr->string);
                add_trailer_item(&arg_tok_first, &arg_tok_last, new);