Replace the existing handwritten implementation of a doubly-linked list
in trailer.c with the functions and macros from list.h. This
significantly simplifies the code.
Signed-off-by: Jonathan Tan <jonathanta...@google.com>
Signed-off-by: Ramsay Jones <ram...@ramsayjones.plus.com>
---
trailer.c | 258 ++++++++++++++++++++++----------------------------------------
1 file changed, 91 insertions(+), 167 deletions(-)
diff --git a/trailer.c b/trailer.c
index 1f191b2..4e85aae 100644
--- a/trailer.c
+++ b/trailer.c
@@ -4,6 +4,7 @@
#include "commit.h"
#include "tempfile.h"
#include "trailer.h"
+#include "list.h"
/*
* Copyright (c) 2013, 2014 Christian Couder <chrisc...@tuxfamily.org>
*/
@@ -25,19 +26,24 @@ struct conf_info {
static struct conf_info default_conf_info;
struct trailer_item {
- struct trailer_item *previous;
- struct trailer_item *next;
+ struct list_head list;
char *token;
char *value;
struct conf_info conf;
};
-static struct trailer_item *first_conf_item;
+static LIST_HEAD(conf_head);
static char *separators = ":";
#define TRAILER_ARG_STRING "$ARG"
+/* Iterate over the elements of the list. */
+#define list_for_each_dir(pos, head, is_reverse) \
+ for (pos = is_reverse ? (head)->prev : (head)->next; \
+ pos != (head); \
+ pos = is_reverse ? pos->prev : pos->next)
+
static int after_or_end(enum action_where where)
{
return (where == WHERE_AFTER) || (where == WHERE_END);
@@ -120,101 +126,49 @@ static void print_tok_val(FILE *outfile, const char
*tok, const char *val)
fprintf(outfile, "%s%c %s\n", tok, separators[0], val);
}
-static void print_all(FILE *outfile, struct trailer_item *first, int
trim_empty)
+static void print_all(FILE *outfile, struct list_head *head, int trim_empty)
{
+ struct list_head *pos;
struct trailer_item *item;
- for (item = first; item; item = item->next) {
+ list_for_each(pos, head) {
+ item = list_entry(pos, struct trailer_item, list);
if (!trim_empty || strlen(item->value) > 0)
print_tok_val(outfile, 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);
- }
+ struct trailer_item *arg_tok)
+{
+ if (after_or_end(arg_tok->conf.where))
+ list_add(&arg_tok->list, &on_tok->list);
+ else
+ list_add_tail(&arg_tok->list, &on_tok->list);
}
static int check_if_different(struct trailer_item *in_tok,
struct trailer_item *arg_tok,
- int check_all)
+ int check_all,
+ struct list_head *head)
{
enum action_where where = arg_tok->conf.where;
+ struct list_head *next_head;
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;
+ next_head = after_or_end(where) ? in_tok->list.prev
+ : in_tok->list.next;
+ if (next_head == head)
+ break;
+ in_tok = list_entry(next_head, struct trailer_item, list);
} 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 char *apply_command(const char *command, const char *arg)
{
struct strbuf cmd = STRBUF_INIT;
@@ -266,8 +220,7 @@ static void apply_item_command(struct trailer_item *in_tok,
struct trailer_item
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)
+ struct list_head *head)
{
switch (arg_tok->conf.if_exists) {
case EXISTS_DO_NOTHING:
@@ -275,40 +228,34 @@ static void apply_arg_if_exists(struct trailer_item
*in_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);
+ add_arg_to_input_list(on_tok, arg_tok);
+ list_del(&in_tok->list);
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);
+ add_arg_to_input_list(on_tok, arg_tok);
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, head))
+ add_arg_to_input_list(on_tok, arg_tok);
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);
+ if (check_if_different(on_tok, arg_tok, 0, head))
+ add_arg_to_input_list(on_tok, arg_tok);
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,
+static void apply_arg_if_missing(struct list_head *head,
struct trailer_item *arg_tok)
{
- struct trailer_item **in_tok;
enum action_where where;
switch (arg_tok->conf.if_missing) {
@@ -317,68 +264,60 @@ static void apply_arg_if_missing(struct trailer_item
**in_tok_first,
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;
+ if (after_or_end(where))
+ list_add_tail(&arg_tok->list, head);
+ else
+ list_add(&arg_tok->list, head);
}
}
-static int find_same_and_apply_arg(struct trailer_item **in_tok_first,
- struct trailer_item **in_tok_last,
+static int find_same_and_apply_arg(struct list_head *head,
struct trailer_item *arg_tok)
{
+ struct list_head *pos;
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;
+ struct trailer_item *start_tok;
- for (in_tok = start_tok; in_tok; in_tok = following_tok) {
- following_tok = backwards ? in_tok->previous : in_tok->next;
+ if (list_empty(head))
+ return 0;
+
+ start_tok = list_entry(backwards ? head->prev : head->next,
+ struct trailer_item,
+ list);
+
+ list_for_each_dir(pos, head, backwards) {
+ in_tok = list_entry(pos, struct trailer_item, list);
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);
+ apply_arg_if_exists(in_tok, arg_tok, on_tok, head);
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)
+static void process_trailers_lists(struct list_head *head,
+ struct list_head *arg_head)
{
+ struct list_head *pos, *p;
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) {
+ list_for_each_safe(pos, p, arg_head) {
int applied = 0;
+ arg_tok = list_entry(pos, struct trailer_item, list);
- next_arg = arg_tok->next;
- remove_from_list(arg_tok, arg_tok_first, NULL);
+ list_del(pos);
- applied = find_same_and_apply_arg(in_tok_first,
- in_tok_last,
- arg_tok);
+ applied = find_same_and_apply_arg(head, arg_tok);
if (!applied)
- apply_arg_if_missing(in_tok_first,
- in_tok_last,
- arg_tok);
+ apply_arg_if_missing(head, arg_tok);
}
}
@@ -438,13 +377,12 @@ static void duplicate_conf(struct conf_info *dst, const
struct conf_info *src)
static struct trailer_item *get_conf_item(const char *name)
{
+ struct list_head *pos;
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) {
+ list_for_each(pos, &conf_head) {
+ item = list_entry(pos, struct trailer_item, list);
if (!strcasecmp(item->conf.name, name))
return item;
}
@@ -454,12 +392,7 @@ static struct trailer_item *get_conf_item(const char *name)
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;
- }
+ list_add_tail(&item->list, &conf_head);
return item;
}
@@ -633,6 +566,7 @@ static struct trailer_item *create_trailer_item(const char
*string)
struct strbuf val = STRBUF_INIT;
struct trailer_item *item;
int tok_len;
+ struct list_head *pos;
if (parse_trailer(&tok, &val, string))
return NULL;
@@ -640,7 +574,8 @@ static struct trailer_item *create_trailer_item(const char
*string)
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) {
+ list_for_each(pos, &conf_head) {
+ item = list_entry(pos, struct trailer_item, list);
if (token_matches_item(tok.buf, item, tok_len))
return new_trailer_item(item,
strbuf_detach(&tok, NULL),
@@ -652,44 +587,34 @@ static struct trailer_item *create_trailer_item(const
char *string)
strbuf_detach(&val, NULL));
}
-static void add_trailer_item(struct trailer_item **first,
- struct trailer_item **last,
- struct trailer_item *new)
+static void add_trailer_item(struct list_head *head, struct trailer_item *new)
{
if (!new)
return;
- if (!*last) {
- *first = new;
- *last = new;
- } else {
- (*last)->next = new;
- new->previous = *last;
- *last = new;
- }
+ list_add_tail(&new->list, head);
}
-static struct trailer_item *process_command_line_args(struct string_list
*trailers)
+static void process_command_line_args(struct list_head *arg_head,
+ 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;
+ struct list_head *pos;
/* Add a trailer item for each configured trailer with a command */
- for (item = first_conf_item; item; item = item->next) {
+ list_for_each(pos, &conf_head) {
+ item = list_entry(pos, struct trailer_item, list);
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_trailer_item(arg_head, 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);
+ add_trailer_item(arg_head, new);
}
-
- return arg_tok_first;
}
static struct strbuf **read_input_file(const char *file)
@@ -805,8 +730,7 @@ static void print_lines(FILE *outfile, struct strbuf
**lines, int start, int end
static int process_input_file(FILE *outfile,
struct strbuf **lines,
- struct trailer_item **in_tok_first,
- struct trailer_item **in_tok_last)
+ struct list_head *head)
{
int count = 0;
int patch_start, trailer_start, trailer_end, i;
@@ -829,18 +753,19 @@ static int process_input_file(FILE *outfile,
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);
+ add_trailer_item(head, new);
}
}
return trailer_end;
}
-static void free_all(struct trailer_item **first)
+static void free_all(struct list_head *head)
{
- while (*first) {
- struct trailer_item *item = remove_first(first);
- free_trailer_item(item);
+ struct list_head *pos, *p;
+ list_for_each_safe(pos, p, head) {
+ list_del(pos);
+ free_trailer_item(list_entry(pos, struct trailer_item, list));
}
}
@@ -877,9 +802,8 @@ static FILE *create_in_place_tempfile(const char *file)
void process_trailers(const char *file, int in_place, 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;
+ LIST_HEAD(head);
+ LIST_HEAD(arg_head);
struct strbuf **lines;
int trailer_end;
FILE *outfile = stdout;
@@ -894,15 +818,15 @@ void process_trailers(const char *file, int in_place, int
trim_empty, struct str
outfile = create_in_place_tempfile(file);
/* Print the lines before the trailers */
- trailer_end = process_input_file(outfile, lines, &in_tok_first,
&in_tok_last);
+ trailer_end = process_input_file(outfile, lines, &head);
- arg_tok_first = process_command_line_args(trailers);
+ process_command_line_args(&arg_head, trailers);
- process_trailers_lists(&in_tok_first, &in_tok_last, &arg_tok_first);
+ process_trailers_lists(&head, &arg_head);
- print_all(outfile, in_tok_first, trim_empty);
+ print_all(outfile, &head, trim_empty);
- free_all(&in_tok_first);
+ free_all(&head);
/* Print the lines after the trailers as is */
print_lines(outfile, lines, trailer_end, INT_MAX);
--
2.8.0.rc3.226.g39d4020
