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[PATCH 3/5] trailer: make args have their own struct

From
JTJonathan Tan <jonathantanmy@google.com>
Date
Oct 12, 2016, 01:23 UTC
Message-ID
<a4fdcf820a1d4c2bd9fe8bf157eab833c1e02044.1476232683.git.jonathantanmy@google.com>
In-Reply-To
<cover.1476232683.git.jonathantanmy@google.com>

Improve type safety by making arguments (whether from configuration or from the command line) have their own "struct arg_item" type, separate from the "struct trailer_item" type used to represent the trailers in the buffer being manipulated.

Also take the opportunity to refine the "struct trailer_item" definition by removing the conf (which is used only by arguments) and by removing const on the string fields, since those fields are owned by the struct.

This change also prepares "struct trailer_item" to be further
differentiated from "struct arg_item" in future patches.
---
 trailer.c | 161 ++++++++++++++++++++++++++++++++++++++------------------------
 1 file changed, 99 insertions(+), 62 deletions(-)
diff --git a/trailer.c b/trailer.c
index e8b1bfb..167b2fd 100644
--- a/trailer.c
+++ b/trailer.c
@@ -26,12 +26,18 @@ static struct conf_info default_conf_info;
 
 struct trailer_item {
 	struct trailer_item *next;
-	const char *token;
-	const char *value;
+	char *token;
+	char *value;
+};
+
+struct arg_item {
+	struct arg_item *next;
+	char *token;
+	char *value;
 	struct conf_info conf;
 };
 
-static struct trailer_item *first_conf_item;
+static struct arg_item *first_conf_item;
 
 static char *separators = ":";
 
@@ -55,8 +61,7 @@ static size_t token_len_without_separator(const char *token, size_t len)
 	return len;
 }
 
-static int same_token(const struct trailer_item *a,
-		      const struct trailer_item *b)
+static int same_token(const struct trailer_item *a, const struct arg_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));
@@ -65,14 +70,12 @@ static int same_token(const struct trailer_item *a,
 	return !strncasecmp(a->token, b->token, min_len);
 }
 
-static int same_value(const struct trailer_item *a,
-		      const struct trailer_item *b)
+static int same_value(const struct trailer_item *a, const struct arg_item *b)
 {
 	return !strcasecmp(a->value, b->value);
 }
 
-static int same_trailer(const struct trailer_item *a,
-			const struct trailer_item *b)
+static int same_trailer(const struct trailer_item *a, const struct arg_item *b)
 {
 	return same_token(a, b) && same_value(a, b);
 }
@@ -94,11 +97,18 @@ static inline void strbuf_replace(struct strbuf *sb, const char *a, const char *
 
 static void free_trailer_item(struct trailer_item *item)
 {
+	free(item->token);
+	free(item->value);
+	free(item);
+}
+
+static void free_arg_item(struct arg_item *item)
+{
 	free(item->conf.name);
 	free(item->conf.key);
 	free(item->conf.command);
-	free((char *)item->token);
-	free((char *)item->value);
+	free(item->token);
+	free(item->value);
 	free(item);
 }
 
@@ -131,13 +141,13 @@ static void print_all(FILE *outfile, struct trailer_item *first, int trim_empty)
 	}
 }
 
-static const char *apply_command(const char *command, const char *arg)
+static 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;
+	char *result;
 
 	strbuf_addstr(&cmd, command);
 	if (arg)
@@ -162,7 +172,7 @@ static const char *apply_command(const char *command, const char *arg)
 	return result;
 }
 
-static void apply_item_command(struct trailer_item *in_tok, struct trailer_item *arg_tok)
+static void apply_item_command(struct trailer_item *in_tok, struct arg_item *arg_tok)
 {
 	if (arg_tok->conf.command) {
 		const char *arg;
@@ -179,60 +189,77 @@ static void apply_item_command(struct trailer_item *in_tok, struct trailer_item
 	}
 }
 
+static struct trailer_item *trailer_from_arg(struct arg_item *arg_tok)
+{
+	struct trailer_item *new = xcalloc(sizeof(*new), 1);
+	new->token = arg_tok->token;
+	new->value = arg_tok->value;
+	arg_tok->token = arg_tok->value = NULL;
+	free_arg_item(arg_tok);
+	return new;
+}
+
 static void apply_existing_arg(struct trailer_item **found_next,
-			       struct trailer_item *arg_tok,
+			       struct arg_item *arg_tok,
 			       struct trailer_item **position_to_add,
 			       const struct trailer_item *in_tok_head,
 			       const struct trailer_item *neighbor)
 {
-	if (arg_tok->conf.if_exists == EXISTS_DO_NOTHING) {
-		free_trailer_item(arg_tok);
+	enum action_if_exists if_exists = arg_tok->conf.if_exists;
+	struct trailer_item *to_add;
+
+	if (if_exists == EXISTS_DO_NOTHING) {
+		free_arg_item(arg_tok);
 		return;
 	}
 
 	apply_item_command(*found_next, arg_tok);
 
-	if (arg_tok->conf.if_exists == EXISTS_ADD_IF_DIFFERENT_NEIGHBOR) {
+	if (if_exists == EXISTS_ADD_IF_DIFFERENT_NEIGHBOR) {
 		if (neighbor && same_trailer(neighbor, arg_tok)) {
-			free_trailer_item(arg_tok);
+			free_arg_item(arg_tok);
 			return;
 		}
-	} else if (arg_tok->conf.if_exists == EXISTS_ADD_IF_DIFFERENT) {
+	} else if (if_exists == EXISTS_ADD_IF_DIFFERENT) {
 		const struct trailer_item *in_tok;
 		for (in_tok = in_tok_head; in_tok; in_tok = in_tok->next) {
 			if (same_trailer(in_tok, arg_tok)) {
-				free_trailer_item(arg_tok);
+				free_arg_item(arg_tok);
 				return;
 			}
 		}
 	}
 
-	arg_tok->next = *position_to_add;
-	*position_to_add = arg_tok;
+	to_add = trailer_from_arg(arg_tok);
+	to_add->next = *position_to_add;
+	*position_to_add = to_add;
 
-	if (arg_tok->conf.if_exists == EXISTS_REPLACE) {
+	if (if_exists == EXISTS_REPLACE) {
 		struct trailer_item *new_next = (*found_next)->next;
 		free_trailer_item(*found_next);
 		*found_next = new_next;
 	}
 }
 
-static void apply_missing_arg(struct trailer_item *arg_tok,
+static void apply_missing_arg(struct arg_item *arg_tok,
 			      struct trailer_item **position_to_add)
 {
+	struct trailer_item *to_add;
+
 	if (arg_tok->conf.if_missing == MISSING_DO_NOTHING) {
-		free_trailer_item(arg_tok);
+		free_arg_item(arg_tok);
 		return;
 	}
 
 	apply_item_command(NULL, arg_tok);
 
-	arg_tok->next = *position_to_add;
-	*position_to_add = arg_tok;
+	to_add = trailer_from_arg(arg_tok);
+	to_add->next = *position_to_add;
+	*position_to_add = to_add;
 }
 
 static void apply_arg(struct trailer_item **in_tok_head,
-		      struct trailer_item *arg_tok)
+		      struct arg_item *arg_tok)
 {
 	struct trailer_item **next, **found_next = NULL, *last = NULL;
 	enum action_where where = arg_tok->conf.where;
@@ -283,9 +310,9 @@ static void apply_arg(struct trailer_item **in_tok_head,
 }
 
 static void process_trailers_lists(struct trailer_item **in_tok_head,
-				   struct trailer_item *arg_tok_head)
+				   struct arg_item *arg_tok_head)
 {
-	struct trailer_item *arg_tok, *next;
+	struct arg_item *arg_tok, *next;
 	for (arg_tok = arg_tok_head; arg_tok; arg_tok = next) {
 		next = arg_tok->next;
 		apply_arg(in_tok_head, arg_tok);
@@ -346,10 +373,10 @@ static void duplicate_conf(struct conf_info *dst, const struct conf_info *src)
 		dst->command = xstrdup(src->command);
 }
 
-static struct trailer_item *get_conf_item(const char *name)
+static struct arg_item *get_conf_item(const char *name)
 {
-	struct trailer_item **next = &first_conf_item;
-	struct trailer_item *item;
+	struct arg_item **next = &first_conf_item;
+	struct arg_item *item;
 
 	/* Look up item with same name */
 	for (next = &first_conf_item; *next; next = &(*next)->next)
@@ -357,7 +384,7 @@ static struct trailer_item *get_conf_item(const char *name)
 			return *next;
 
 	/* Item does not already exists, create it */
-	item = xcalloc(sizeof(struct trailer_item), 1);
+	item = xcalloc(sizeof(*item), 1);
 	duplicate_conf(&item->conf, &default_conf_info);
 	item->conf.name = xstrdup(name);
 	*next = item;
@@ -409,7 +436,7 @@ static int git_trailer_default_config(const char *conf_key, const char *value, v
 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 arg_item *item;
 	struct conf_info *conf;
 	char *name = NULL;
 	enum trailer_info_type type;
@@ -467,7 +494,7 @@ static int git_trailer_config(const char *conf_key, const char *value, void *cb)
 	return 0;
 }
 
-static const char *token_from_item(struct trailer_item *item, char *tok)
+static const char *token_from_item(struct arg_item *item, char *tok)
 {
 	if (item->conf.key)
 		return item->conf.key;
@@ -476,7 +503,7 @@ static const char *token_from_item(struct trailer_item *item, char *tok)
 	return item->conf.name;
 }
 
-static int token_matches_item(const char *tok, struct trailer_item *item, int tok_len)
+static int token_matches_item(const char *tok, struct arg_item *item, int tok_len)
 {
 	if (!strncasecmp(tok, item->conf.name, tok_len))
 		return 1;
@@ -488,7 +515,7 @@ static int parse_trailer(struct strbuf *tok, struct strbuf *val,
 {
 	size_t len;
 	struct strbuf seps = STRBUF_INIT;
-	struct trailer_item *item;
+	struct arg_item *item;
 	int tok_len;
 
 	strbuf_addstr(&seps, separators);
@@ -513,11 +540,13 @@ static int parse_trailer(struct strbuf *tok, struct strbuf *val,
 
 	/* Lookup if the token matches something in the config */
 	tok_len = token_len_without_separator(tok->buf, tok->len);
-	*conf = &default_conf_info;
+	if (conf)
+		*conf = &default_conf_info;
 	for (item = first_conf_item; item; item = item->next) {
 		if (token_matches_item(tok->buf, item, tok_len)) {
 			char *tok_buf = strbuf_detach(tok, NULL);
-			*conf = &item->conf;
+			if (conf)
+				*conf = &item->conf;
 			strbuf_addstr(tok, token_from_item(item, tok_buf));
 			free(tok_buf);
 			break;
@@ -527,43 +556,53 @@ static int parse_trailer(struct strbuf *tok, struct strbuf *val,
 	return 0;
 }
 
-static void add_trailer_item(struct trailer_item ***tail, char *tok, char *val,
-			     const struct conf_info *conf)
+static void add_trailer_item(struct trailer_item ***tail, char *tok, char *val)
 {
 	struct trailer_item *new = xcalloc(sizeof(*new), 1);
 	new->token = tok;
 	new->value = val;
+
+	**tail = new;
+	*tail = &new->next;
+}
+
+static void add_arg_item(struct arg_item ***tail, char *tok, char *val,
+			 const struct conf_info *conf)
+{
+	struct arg_item *new = xcalloc(sizeof(*new), 1);
+	new->token = tok;
+	new->value = val;
 	duplicate_conf(&new->conf, conf);
 
 	**tail = new;
 	*tail = &new->next;
 }
 
-static struct trailer_item *process_command_line_args(struct string_list *trailers)
+static struct arg_item *process_command_line_args(struct string_list *trailers)
 {
-	struct trailer_item *arg_tok_head = NULL;
-	struct trailer_item **arg_tok_tail = &arg_tok_head;
+	struct arg_item *arg_tok_head = NULL;
+	struct arg_item **arg_tok_tail = &arg_tok_head;
 	struct string_list_item *tr;
-	struct trailer_item *item;
+	struct arg_item *item;
 	struct strbuf tok = STRBUF_INIT;
 	struct strbuf val = STRBUF_INIT;
 	const struct conf_info *conf;
 
-	/* Add a trailer item for each configured trailer with a command */
+	/* Add an arg item for each configured trailer with a command */
 	for (item = first_conf_item; item; item = item->next)
 		if (item->conf.command)
-			add_trailer_item(&arg_tok_tail,
-					 xstrdup(token_from_item(item, NULL)),
-					 xstrdup(""),
-					 &item->conf);
+			add_arg_item(&arg_tok_tail,
+				     xstrdup(token_from_item(item, NULL)),
+				     xstrdup(""),
+				     &item->conf);
 
-	/* Add a trailer item for each trailer on the command line */
+	/* Add an arg item for each trailer on the command line */
 	for_each_string_list_item(tr, trailers) {
 		if (!parse_trailer(&tok, &val, &conf, tr->string))
-			add_trailer_item(&arg_tok_tail,
-					 strbuf_detach(&tok, NULL),
-					 strbuf_detach(&val, NULL),
-					 conf);
+			add_arg_item(&arg_tok_tail,
+				     strbuf_detach(&tok, NULL),
+				     strbuf_detach(&val, NULL),
+				     conf);
 	}
 
 	return arg_tok_head;
@@ -688,7 +727,6 @@ static int process_input_file(FILE *outfile,
 	int patch_start, trailer_start, trailer_end, i;
 	struct strbuf tok = STRBUF_INIT;
 	struct strbuf val = STRBUF_INIT;
-	const struct conf_info *conf;
 
 	/* Get the line count */
 	while (lines[count])
@@ -707,11 +745,10 @@ static int process_input_file(FILE *outfile,
 	/* Parse trailer lines */
 	for (i = trailer_start; i < trailer_end; i++) {
 		if (lines[i]->buf[0] != comment_line_char &&
-		    !parse_trailer(&tok, &val, &conf, lines[i]->buf))
+		    !parse_trailer(&tok, &val, NULL, lines[i]->buf))
 			add_trailer_item(in_tok_tail,
 					 strbuf_detach(&tok, NULL),
-					 strbuf_detach(&val, NULL),
-					 conf);
+					 strbuf_detach(&val, NULL));
 	}
 
 	return trailer_end;
@@ -761,7 +798,7 @@ void process_trailers(const char *file, int in_place, int trim_empty, struct str
 {
 	struct trailer_item *in_tok_head = NULL;
 	struct trailer_item **in_tok_tail = &in_tok_head;
-	struct trailer_item *arg_tok_head;
+	struct arg_item *arg_tok_head;
 	struct strbuf **lines;
 	int trailer_end;
 	FILE *outfile = stdout;
-- 
2.8.0.rc3.226.g39d4020
Previous: Jonathan TanNext: Jonathan Tan
Message 10 of 48 in “allow non-trailers and multiple-line trailers”
  1. 0/5 allow non-trailers and multiple-line trailersJonathan Tan, Oct 12, 2016
  2. 1/5 trailer: use singly-linked list, not doublyJonathan Tan, Oct 12, 2016
  3. Junio C HamanoOct 12, 2016
  4. Christian CouderOct 12, 2016
  5. Jeff KingOct 12, 2016
  6. 5/5 trailer: support values folded to multiple linesJonathan Tan, Oct 12, 2016
  7. Junio C HamanoOct 12, 2016
  8. 2/5 trailer: streamline trailer item create and addJonathan Tan, Oct 12, 2016
  9. 4/5 trailer: allow non-trailers in trailer blockJonathan Tan, Oct 12, 2016
  10. 3/5 trailer: make args have their own structJonathan Tan, Oct 12, 2016
  11. 0/6 allow non-trailers and multiple-line trailersJonathan Tan, Oct 12, 2016
  12. 1/6 trailer: improve const correctnessJonathan Tan, Oct 12, 2016
  13. 2/6 trailer: use list.h for doubly-linked listJonathan Tan, Oct 12, 2016
  14. Junio C HamanoOct 14, 2016
  15. Jakub NarębskiOct 14, 2016
  16. 3/6 trailer: streamline trailer item create and addJonathan Tan, Oct 12, 2016
  17. 4/6 trailer: make args have their own structJonathan Tan, Oct 12, 2016
  18. 5/6 trailer: allow non-trailers in trailer blockJonathan Tan, Oct 12, 2016
  19. 6/6 trailer: support values folded to multiple linesJonathan Tan, Oct 12, 2016
  20. 0/6 allow non-trailers and multiple-line trailersJonathan Tan, Oct 14, 2016
  21. 1/6 trailer: improve const correctnessJonathan Tan, Oct 14, 2016
  22. Stefan BellerOct 17, 2016
  23. 2/6 trailer: use list.h for doubly-linked listJonathan Tan, Oct 14, 2016
  24. 3/6 trailer: streamline trailer item create and addJonathan Tan, Oct 14, 2016
  25. Stefan BellerOct 17, 2016
  26. 5/6 trailer: allow non-trailers in trailer blockJonathan Tan, Oct 14, 2016
  27. Stefan BellerOct 18, 2016
  28. Junio C HamanoOct 18, 2016
  29. Jonathan TanOct 18, 2016
  30. Junio C HamanoOct 18, 2016
  31. Jonathan TanOct 19, 2016
  32. Junio C HamanoOct 19, 2016
  33. 6/6 trailer: support values folded to multiple linesJonathan Tan, Oct 14, 2016
  34. Stefan BellerOct 18, 2016
  35. 4/6 trailer: make args have their own structJonathan Tan, Oct 14, 2016
  36. Stefan BellerOct 17, 2016
  37. Junio C HamanoOct 18, 2016
  38. 0/8 allow non-trailers and multiple-line trailersJonathan Tan, Oct 21, 2016
  39. 1/8 trailer: improve const correctnessJonathan Tan, Oct 21, 2016
  40. 5/8 trailer: clarify failure modes in parse_trailerJonathan Tan, Oct 21, 2016
  41. 4/8 trailer: make args have their own structJonathan Tan, Oct 21, 2016
  42. 7/8 trailer: forbid leading whitespace in trailersJonathan Tan, Oct 21, 2016
  43. 6/8 trailer: allow non-trailers in trailer blockJonathan Tan, Oct 21, 2016
  44. 8/8 trailer: support values folded to multiple linesJonathan Tan, Oct 21, 2016
  45. 3/8 trailer: streamline trailer item create and addJonathan Tan, Oct 21, 2016
  46. 2/8 trailer: use list.h for doubly-linked listJonathan Tan, Oct 21, 2016
  47. Junio C HamanoOct 21, 2016
  48. Stefan BellerOct 22, 2016

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