git/trailer.c
Jeff King c5eadcaab1 trailer: use capture_command
When we read from a trailer.*.command sub-program, the
current code uses run_command followed by a pipe read, which
can result in deadlock (though in practice you would have to
have a large trailer for this to be a problem). The current
code also leaks the file descriptor for the pipe to the
sub-command.

Instead, let's use capture_command, which makes this simpler
(and we can get rid of our custom helper).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-22 21:39:18 -07:00

866 lines
21 KiB
C

#include "cache.h"
#include "string-list.h"
#include "run-command.h"
#include "commit.h"
#include "trailer.h"
/*
* Copyright (c) 2013, 2014 Christian Couder <chriscool@tuxfamily.org>
*/
enum action_where { WHERE_END, WHERE_AFTER, WHERE_BEFORE, WHERE_START };
enum action_if_exists { EXISTS_ADD_IF_DIFFERENT_NEIGHBOR, EXISTS_ADD_IF_DIFFERENT,
EXISTS_ADD, EXISTS_REPLACE, EXISTS_DO_NOTHING };
enum action_if_missing { MISSING_ADD, MISSING_DO_NOTHING };
struct conf_info {
char *name;
char *key;
char *command;
enum action_where where;
enum action_if_exists if_exists;
enum action_if_missing if_missing;
};
static struct conf_info default_conf_info;
struct trailer_item {
struct trailer_item *previous;
struct trailer_item *next;
const char *token;
const char *value;
struct conf_info conf;
};
static struct trailer_item *first_conf_item;
static char *separators = ":";
#define TRAILER_ARG_STRING "$ARG"
static int after_or_end(enum action_where where)
{
return (where == WHERE_AFTER) || (where == WHERE_END);
}
/*
* Return the length of the string not including any final
* punctuation. E.g., the input "Signed-off-by:" would return
* 13, stripping the trailing punctuation but retaining
* internal punctuation.
*/
static size_t token_len_without_separator(const char *token, size_t len)
{
while (len > 0 && !isalnum(token[len - 1]))
len--;
return len;
}
static int same_token(struct trailer_item *a, struct trailer_item *b)
{
size_t a_len = token_len_without_separator(a->token, strlen(a->token));
size_t b_len = token_len_without_separator(b->token, strlen(b->token));
size_t min_len = (a_len > b_len) ? b_len : a_len;
return !strncasecmp(a->token, b->token, min_len);
}
static int same_value(struct trailer_item *a, struct trailer_item *b)
{
return !strcasecmp(a->value, b->value);
}
static int same_trailer(struct trailer_item *a, struct trailer_item *b)
{
return same_token(a, b) && same_value(a, b);
}
static inline int contains_only_spaces(const char *str)
{
const char *s = str;
while (*s && isspace(*s))
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);
free(item->conf.key);
free(item->conf.command);
free((char *)item->token);
free((char *)item->value);
free(item);
}
static char last_non_space_char(const char *s)
{
int i;
for (i = strlen(s) - 1; i >= 0; i--)
if (!isspace(s[i]))
return s[i];
return '\0';
}
static void print_tok_val(const char *tok, const char *val)
{
char c = last_non_space_char(tok);
if (!c)
return;
if (strchr(separators, c))
printf("%s%s\n", tok, val);
else
printf("%s%c %s\n", tok, separators[0], val);
}
static void print_all(struct trailer_item *first, int trim_empty)
{
struct trailer_item *item;
for (item = first; item; item = item->next) {
if (!trim_empty || strlen(item->value) > 0)
print_tok_val(item->token, item->value);
}
}
static void update_last(struct trailer_item **last)
{
if (*last)
while ((*last)->next != NULL)
*last = (*last)->next;
}
static void update_first(struct trailer_item **first)
{
if (*first)
while ((*first)->previous != NULL)
*first = (*first)->previous;
}
static void add_arg_to_input_list(struct trailer_item *on_tok,
struct trailer_item *arg_tok,
struct trailer_item **first,
struct trailer_item **last)
{
if (after_or_end(arg_tok->conf.where)) {
arg_tok->next = on_tok->next;
on_tok->next = arg_tok;
arg_tok->previous = on_tok;
if (arg_tok->next)
arg_tok->next->previous = arg_tok;
update_last(last);
} else {
arg_tok->previous = on_tok->previous;
on_tok->previous = arg_tok;
arg_tok->next = on_tok;
if (arg_tok->previous)
arg_tok->previous->next = arg_tok;
update_first(first);
}
}
static int check_if_different(struct trailer_item *in_tok,
struct trailer_item *arg_tok,
int check_all)
{
enum action_where where = arg_tok->conf.where;
do {
if (!in_tok)
return 1;
if (same_trailer(in_tok, arg_tok))
return 0;
/*
* if we want to add a trailer after another one,
* we have to check those before this one
*/
in_tok = after_or_end(where) ? in_tok->previous : in_tok->next;
} while (check_all);
return 1;
}
static void remove_from_list(struct trailer_item *item,
struct trailer_item **first,
struct trailer_item **last)
{
struct trailer_item *next = item->next;
struct trailer_item *previous = item->previous;
if (next) {
item->next->previous = previous;
item->next = NULL;
} else if (last)
*last = previous;
if (previous) {
item->previous->next = next;
item->previous = NULL;
} else if (first)
*first = next;
}
static struct trailer_item *remove_first(struct trailer_item **first)
{
struct trailer_item *item = *first;
*first = item->next;
if (item->next) {
item->next->previous = NULL;
item->next = NULL;
}
return item;
}
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 = CHILD_PROCESS_INIT;
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;
cp.argv = argv;
cp.env = local_repo_env;
cp.no_stdin = 1;
cp.use_shell = 1;
if (capture_command(&cp, &buf, 1024)) {
error("running trailer command '%s' failed", cmd.buf);
strbuf_release(&buf);
result = xstrdup("");
} else {
strbuf_trim(&buf);
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,
struct trailer_item **in_tok_first,
struct trailer_item **in_tok_last)
{
switch (arg_tok->conf.if_exists) {
case EXISTS_DO_NOTHING:
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:
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:
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);
else
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);
else
free_trailer_item(arg_tok);
break;
}
}
static void apply_arg_if_missing(struct trailer_item **in_tok_first,
struct trailer_item **in_tok_last,
struct trailer_item *arg_tok)
{
struct trailer_item **in_tok;
enum action_where where;
switch (arg_tok->conf.if_missing) {
case MISSING_DO_NOTHING:
free_trailer_item(arg_tok);
break;
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);
} else {
*in_tok_first = arg_tok;
*in_tok_last = arg_tok;
}
break;
}
}
static int find_same_and_apply_arg(struct trailer_item **in_tok_first,
struct trailer_item **in_tok_last,
struct trailer_item *arg_tok)
{
struct trailer_item *in_tok;
struct trailer_item *on_tok;
struct trailer_item *following_tok;
enum action_where where = arg_tok->conf.where;
int middle = (where == WHERE_AFTER) || (where == WHERE_BEFORE);
int backwards = after_or_end(where);
struct trailer_item *start_tok = backwards ? *in_tok_last : *in_tok_first;
for (in_tok = start_tok; in_tok; in_tok = following_tok) {
following_tok = backwards ? in_tok->previous : in_tok->next;
if (!same_token(in_tok, arg_tok))
continue;
on_tok = middle ? in_tok : start_tok;
apply_arg_if_exists(in_tok, arg_tok, on_tok,
in_tok_first, in_tok_last);
return 1;
}
return 0;
}
static void process_trailers_lists(struct trailer_item **in_tok_first,
struct trailer_item **in_tok_last,
struct trailer_item **arg_tok_first)
{
struct trailer_item *arg_tok;
struct trailer_item *next_arg;
if (!*arg_tok_first)
return;
for (arg_tok = *arg_tok_first; arg_tok; arg_tok = next_arg) {
int applied = 0;
next_arg = arg_tok->next;
remove_from_list(arg_tok, arg_tok_first, NULL);
applied = find_same_and_apply_arg(in_tok_first,
in_tok_last,
arg_tok);
if (!applied)
apply_arg_if_missing(in_tok_first,
in_tok_last,
arg_tok);
}
}
static int set_where(struct conf_info *item, const char *value)
{
if (!strcasecmp("after", value))
item->where = WHERE_AFTER;
else if (!strcasecmp("before", value))
item->where = WHERE_BEFORE;
else if (!strcasecmp("end", value))
item->where = WHERE_END;
else if (!strcasecmp("start", value))
item->where = WHERE_START;
else
return -1;
return 0;
}
static int set_if_exists(struct conf_info *item, const char *value)
{
if (!strcasecmp("addIfDifferent", value))
item->if_exists = EXISTS_ADD_IF_DIFFERENT;
else if (!strcasecmp("addIfDifferentNeighbor", value))
item->if_exists = EXISTS_ADD_IF_DIFFERENT_NEIGHBOR;
else if (!strcasecmp("add", value))
item->if_exists = EXISTS_ADD;
else if (!strcasecmp("replace", value))
item->if_exists = EXISTS_REPLACE;
else if (!strcasecmp("doNothing", value))
item->if_exists = EXISTS_DO_NOTHING;
else
return -1;
return 0;
}
static int set_if_missing(struct conf_info *item, const char *value)
{
if (!strcasecmp("doNothing", value))
item->if_missing = MISSING_DO_NOTHING;
else if (!strcasecmp("add", value))
item->if_missing = MISSING_ADD;
else
return -1;
return 0;
}
static void duplicate_conf(struct conf_info *dst, struct conf_info *src)
{
*dst = *src;
if (src->name)
dst->name = xstrdup(src->name);
if (src->key)
dst->key = xstrdup(src->key);
if (src->command)
dst->command = xstrdup(src->command);
}
static struct trailer_item *get_conf_item(const char *name)
{
struct trailer_item *item;
struct trailer_item *previous;
/* Look up item with same name */
for (previous = NULL, item = first_conf_item;
item;
previous = item, item = item->next) {
if (!strcasecmp(item->conf.name, name))
return item;
}
/* Item does not already exists, create it */
item = xcalloc(sizeof(struct trailer_item), 1);
duplicate_conf(&item->conf, &default_conf_info);
item->conf.name = xstrdup(name);
if (!previous)
first_conf_item = item;
else {
previous->next = item;
item->previous = previous;
}
return item;
}
enum trailer_info_type { TRAILER_KEY, TRAILER_COMMAND, TRAILER_WHERE,
TRAILER_IF_EXISTS, TRAILER_IF_MISSING };
static struct {
const char *name;
enum trailer_info_type type;
} trailer_config_items[] = {
{ "key", TRAILER_KEY },
{ "command", TRAILER_COMMAND },
{ "where", TRAILER_WHERE },
{ "ifexists", TRAILER_IF_EXISTS },
{ "ifmissing", TRAILER_IF_MISSING }
};
static int git_trailer_default_config(const char *conf_key, const char *value, void *cb)
{
const char *trailer_item, *variable_name;
if (!skip_prefix(conf_key, "trailer.", &trailer_item))
return 0;
variable_name = strrchr(trailer_item, '.');
if (!variable_name) {
if (!strcmp(trailer_item, "where")) {
if (set_where(&default_conf_info, value) < 0)
warning(_("unknown value '%s' for key '%s'"),
value, conf_key);
} else if (!strcmp(trailer_item, "ifexists")) {
if (set_if_exists(&default_conf_info, value) < 0)
warning(_("unknown value '%s' for key '%s'"),
value, conf_key);
} else if (!strcmp(trailer_item, "ifmissing")) {
if (set_if_missing(&default_conf_info, value) < 0)
warning(_("unknown value '%s' for key '%s'"),
value, conf_key);
} else if (!strcmp(trailer_item, "separators")) {
separators = xstrdup(value);
}
}
return 0;
}
static int git_trailer_config(const char *conf_key, const char *value, void *cb)
{
const char *trailer_item, *variable_name;
struct trailer_item *item;
struct conf_info *conf;
char *name = NULL;
enum trailer_info_type type;
int i;
if (!skip_prefix(conf_key, "trailer.", &trailer_item))
return 0;
variable_name = strrchr(trailer_item, '.');
if (!variable_name)
return 0;
variable_name++;
for (i = 0; i < ARRAY_SIZE(trailer_config_items); i++) {
if (strcmp(trailer_config_items[i].name, variable_name))
continue;
name = xstrndup(trailer_item, variable_name - trailer_item - 1);
type = trailer_config_items[i].type;
break;
}
if (!name)
return 0;
item = get_conf_item(name);
conf = &item->conf;
free(name);
switch (type) {
case TRAILER_KEY:
if (conf->key)
warning(_("more than one %s"), conf_key);
conf->key = xstrdup(value);
break;
case TRAILER_COMMAND:
if (conf->command)
warning(_("more than one %s"), conf_key);
conf->command = xstrdup(value);
break;
case TRAILER_WHERE:
if (set_where(conf, value))
warning(_("unknown value '%s' for key '%s'"), value, conf_key);
break;
case TRAILER_IF_EXISTS:
if (set_if_exists(conf, value))
warning(_("unknown value '%s' for key '%s'"), value, conf_key);
break;
case TRAILER_IF_MISSING:
if (set_if_missing(conf, value))
warning(_("unknown value '%s' for key '%s'"), value, conf_key);
break;
default:
die("internal bug in trailer.c");
}
return 0;
}
static int parse_trailer(struct strbuf *tok, struct strbuf *val, const char *trailer)
{
size_t len;
struct strbuf seps = STRBUF_INIT;
strbuf_addstr(&seps, separators);
strbuf_addch(&seps, '=');
len = strcspn(trailer, seps.buf);
strbuf_release(&seps);
if (len == 0) {
int l = strlen(trailer);
while (l > 0 && isspace(trailer[l - 1]))
l--;
return error(_("empty trailer token in trailer '%.*s'"), l, trailer);
}
if (len < strlen(trailer)) {
strbuf_add(tok, trailer, len);
strbuf_trim(tok);
strbuf_addstr(val, trailer + len + 1);
strbuf_trim(val);
} else {
strbuf_addstr(tok, trailer);
strbuf_trim(tok);
}
return 0;
}
static const char *token_from_item(struct trailer_item *item, char *tok)
{
if (item->conf.key)
return item->conf.key;
if (tok)
return tok;
return item->conf.name;
}
static struct trailer_item *new_trailer_item(struct trailer_item *conf_item,
char *tok, char *val)
{
struct trailer_item *new = xcalloc(sizeof(*new), 1);
new->value = val ? val : xstrdup("");
if (conf_item) {
duplicate_conf(&new->conf, &conf_item->conf);
new->token = xstrdup(token_from_item(conf_item, tok));
free(tok);
} else {
duplicate_conf(&new->conf, &default_conf_info);
new->token = tok;
}
return new;
}
static int token_matches_item(const char *tok, struct trailer_item *item, int tok_len)
{
if (!strncasecmp(tok, item->conf.name, tok_len))
return 1;
return item->conf.key ? !strncasecmp(tok, item->conf.key, tok_len) : 0;
}
static struct trailer_item *create_trailer_item(const char *string)
{
struct strbuf tok = STRBUF_INIT;
struct strbuf val = STRBUF_INIT;
struct trailer_item *item;
int tok_len;
if (parse_trailer(&tok, &val, string))
return NULL;
tok_len = token_len_without_separator(tok.buf, tok.len);
/* Lookup if the token matches something in the config */
for (item = first_conf_item; item; item = item->next) {
if (token_matches_item(tok.buf, item, tok_len))
return new_trailer_item(item,
strbuf_detach(&tok, NULL),
strbuf_detach(&val, NULL));
}
return new_trailer_item(NULL,
strbuf_detach(&tok, NULL),
strbuf_detach(&val, NULL));
}
static void add_trailer_item(struct trailer_item **first,
struct trailer_item **last,
struct trailer_item *new)
{
if (!new)
return;
if (!*last) {
*first = new;
*last = new;
} else {
(*last)->next = new;
new->previous = *last;
*last = new;
}
}
static struct trailer_item *process_command_line_args(struct string_list *trailers)
{
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);
}
return arg_tok_first;
}
static struct strbuf **read_input_file(const char *file)
{
struct strbuf **lines;
struct strbuf sb = STRBUF_INIT;
if (file) {
if (strbuf_read_file(&sb, file, 0) < 0)
die_errno(_("could not read input file '%s'"), file);
} else {
if (strbuf_read(&sb, fileno(stdin), 0) < 0)
die_errno(_("could not read from stdin"));
}
lines = strbuf_split(&sb, '\n');
strbuf_release(&sb);
return lines;
}
/*
* Return the (0 based) index of the start of the patch or the line
* count if there is no patch in the message.
*/
static int find_patch_start(struct strbuf **lines, int count)
{
int i;
/* Get the start of the patch part if any */
for (i = 0; i < count; i++) {
if (starts_with(lines[i]->buf, "---"))
return i;
}
return count;
}
/*
* Return the (0 based) index of the first trailer line or count if
* there are no trailers. Trailers are searched only in the lines from
* index (count - 1) down to index 0.
*/
static int find_trailer_start(struct strbuf **lines, int count)
{
int start, only_spaces = 1;
/*
* Get the start of the trailers by looking starting from the end
* for a line with only spaces before lines with one separator.
*/
for (start = count - 1; start >= 0; start--) {
if (lines[start]->buf[0] == comment_line_char)
continue;
if (contains_only_spaces(lines[start]->buf)) {
if (only_spaces)
continue;
return start + 1;
}
if (strcspn(lines[start]->buf, separators) < lines[start]->len) {
if (only_spaces)
only_spaces = 0;
continue;
}
return count;
}
return only_spaces ? count : 0;
}
/* Get the index of the end of the trailers */
static int find_trailer_end(struct strbuf **lines, int patch_start)
{
struct strbuf sb = STRBUF_INIT;
int i, ignore_bytes;
for (i = 0; i < patch_start; i++)
strbuf_addbuf(&sb, lines[i]);
ignore_bytes = ignore_non_trailer(&sb);
strbuf_release(&sb);
for (i = patch_start - 1; i >= 0 && ignore_bytes > 0; i--)
ignore_bytes -= lines[i]->len;
return i + 1;
}
static int has_blank_line_before(struct strbuf **lines, int start)
{
for (;start >= 0; start--) {
if (lines[start]->buf[0] == comment_line_char)
continue;
return contains_only_spaces(lines[start]->buf);
}
return 0;
}
static void print_lines(struct strbuf **lines, int start, int end)
{
int i;
for (i = start; lines[i] && i < end; i++)
printf("%s", lines[i]->buf);
}
static int process_input_file(struct strbuf **lines,
struct trailer_item **in_tok_first,
struct trailer_item **in_tok_last)
{
int count = 0;
int patch_start, trailer_start, trailer_end, i;
/* Get the line count */
while (lines[count])
count++;
patch_start = find_patch_start(lines, count);
trailer_end = find_trailer_end(lines, patch_start);
trailer_start = find_trailer_start(lines, trailer_end);
/* Print lines before the trailers as is */
print_lines(lines, 0, trailer_start);
if (!has_blank_line_before(lines, trailer_start - 1))
printf("\n");
/* Parse trailer lines */
for (i = trailer_start; i < trailer_end; i++) {
if (lines[i]->buf[0] != comment_line_char) {
struct trailer_item *new = create_trailer_item(lines[i]->buf);
add_trailer_item(in_tok_first, in_tok_last, new);
}
}
return trailer_end;
}
static void free_all(struct trailer_item **first)
{
while (*first) {
struct trailer_item *item = remove_first(first);
free_trailer_item(item);
}
}
void process_trailers(const char *file, int trim_empty, struct string_list *trailers)
{
struct trailer_item *in_tok_first = NULL;
struct trailer_item *in_tok_last = NULL;
struct trailer_item *arg_tok_first;
struct strbuf **lines;
int trailer_end;
/* Default config must be setup first */
git_config(git_trailer_default_config, NULL);
git_config(git_trailer_config, NULL);
lines = read_input_file(file);
/* Print the lines before the trailers */
trailer_end = process_input_file(lines, &in_tok_first, &in_tok_last);
arg_tok_first = process_command_line_args(trailers);
process_trailers_lists(&in_tok_first, &in_tok_last, &arg_tok_first);
print_all(in_tok_first, trim_empty);
free_all(&in_tok_first);
/* Print the lines after the trailers as is */
print_lines(lines, trailer_end, INT_MAX);
strbuf_list_free(lines);
}