lineedit: allocate matchBuf only temporarily: saves MAX_LINELEN bytes
function old new delta
input_tab 1027 1041 +14
build_match_prefix 590 562 -28
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 14/-28) Total: -14 bytes
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index ff5d284..a917c5f 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -150,11 +150,6 @@
#if ENABLE_FEATURE_EDITING_ASK_TERMINAL
smallint sent_ESC_br6n;
#endif
-
- /* Formerly these were big buffers on stack: */
-#if ENABLE_FEATURE_TAB_COMPLETION
- char input_tab__matchBuf[MAX_LINELEN];
-#endif
};
/* See lineedit_ptr_hack.c */
@@ -810,17 +805,17 @@
}
/* build_match_prefix:
- * On entry, matchBuf contains everything up to cursor at the moment <tab>
+ * On entry, match_buf contains everything up to cursor at the moment <tab>
* was pressed. This function looks at it, figures out what part of it
* constitutes the command/file/directory prefix to use for completion,
- * and rewrites matchBuf to contain only that part.
+ * and rewrites match_buf to contain only that part.
*/
+#define dbg_bmp 0
/* Helpers: */
/* QUOT is used on elements of int_buf[], which are bytes,
* not Unicode chars. Therefore it works correctly even in Unicode mode.
*/
#define QUOT (UCHAR_MAX+1)
-#define dbg_bmp 0
static void remove_chunk(int16_t *int_buf, int beg, int end)
{
/* beg must be <= end */
@@ -837,25 +832,29 @@
bb_putchar('\n');
}
}
-static NOINLINE int build_match_prefix(char *matchBuf)
+/* Caller ensures that match_buf points to a malloced buffer
+ * big enough to hold strlen(match_buf)*2 + 2
+ */
+static NOINLINE int build_match_prefix(char *match_buf)
{
int i, j;
int command_mode;
- int16_t *int_buf;
+ int16_t *int_buf = (int16_t*)match_buf;
- if (dbg_bmp) printf("\n%s\n", matchBuf);
+ if (dbg_bmp) printf("\n%s\n", match_buf);
- int_buf = xmalloc(sizeof(int_buf[0]) * (strlen(matchBuf) + 1));
- i = 0;
- while ((int_buf[i] = (unsigned char)matchBuf[i]) != '\0')
- i++;
+ /* Copy in reverse order, since they overlap */
+ i = strlen(match_buf);
+ do {
+ int_buf[i] = (unsigned char)match_buf[i];
+ i--;
+ } while (i >= 0);
/* Mark every \c as "quoted c" */
- for (i = j = 0; matchBuf[i]; i++, j++) {
- if (matchBuf[i] == '\\') {
- remove_chunk(int_buf, j, j + 1);
- int_buf[j] |= QUOT;
- i++;
+ for (i = 0; int_buf[i]; i++) {
+ if (int_buf[i] == '\\') {
+ remove_chunk(int_buf, i, i + 1);
+ int_buf[i] |= QUOT;
}
}
/* Quote-mark "chars" and 'chars', drop delimiters */
@@ -964,13 +963,12 @@
}
}
- /* Store only match prefix */
+ /* Convert back to string of _chars_ */
i = 0;
- while ((matchBuf[i] = int_buf[i]) != '\0')
+ while ((match_buf[i] = int_buf[i]) != '\0')
i++;
- free(int_buf);
- if (dbg_bmp) printf("final matchBuf:'%s'\n", matchBuf);
+ if (dbg_bmp) printf("final match_buf:'%s'\n", match_buf);
return command_mode;
}
@@ -1037,9 +1035,8 @@
static NOINLINE void input_tab(smallint *lastWasTab)
{
char *chosen_match;
+ char *match_buf;
size_t len_found;
-/* char matchBuf[MAX_LINELEN]; */
-#define matchBuf (S.input_tab__matchBuf)
/* Length of string used for matching */
unsigned match_pfx_len = match_pfx_len;
int find_type;
@@ -1065,21 +1062,26 @@
}
*lastWasTab = 1;
+ chosen_match = NULL;
- /* Make a local copy of the string --
- * up to the position of the cursor */
+ /* Make a local copy of the string up to the position of the cursor.
+ * build_match_prefix will expand it into int16_t's, need to allocate
+ * twice as much as the string_len+1.
+ * (we then also (ab)use this extra space later - see (**))
+ */
+ match_buf = xmalloc(MAX_LINELEN * sizeof(int16_t));
#if !ENABLE_UNICODE_SUPPORT
- save_string(matchBuf, cursor + 1);
+ save_string(match_buf, cursor + 1); /* +1 for NUL */
#else
{
CHAR_T wc = command_ps[cursor];
command_ps[cursor] = BB_NUL;
- save_string(matchBuf, MAX_LINELEN);
+ save_string(match_buf, MAX_LINELEN);
command_ps[cursor] = wc;
- cursor_mb = strlen(matchBuf);
+ cursor_mb = strlen(match_buf);
}
#endif
- find_type = build_match_prefix(matchBuf);
+ find_type = build_match_prefix(match_buf);
/* Free up any memory already allocated */
free_tab_completion_data();
@@ -1088,12 +1090,12 @@
/* If the word starts with `~' and there is no slash in the word,
* then try completing this word as a username. */
if (state->flags & USERNAME_COMPLETION)
- if (matchBuf[0] == '~' && strchr(matchBuf, '/') == NULL)
- match_pfx_len = complete_username(matchBuf);
+ if (match_buf[0] == '~' && strchr(match_buf, '/') == NULL)
+ match_pfx_len = complete_username(match_buf);
#endif
/* Try to match a command in $PATH, or a directory, or a file */
if (!matches)
- match_pfx_len = complete_cmd_dir_file(matchBuf, find_type);
+ match_pfx_len = complete_cmd_dir_file(match_buf, find_type);
/* Remove duplicates */
if (matches) {
unsigned i;
@@ -1117,7 +1119,7 @@
char *cp;
beep();
if (!matches)
- return; /* no matches at all */
+ goto ret; /* no matches at all */
/* Find common prefix */
chosen_match = xstrdup(matches[0]);
for (cp = chosen_match; *cp; cp++) {
@@ -1130,8 +1132,7 @@
}
stop:
if (cp == chosen_match) { /* have unique prefix? */
- free(chosen_match); /* no */
- return;
+ goto ret; /* no */
}
*cp = '\0';
cp = add_quote_for_spec_chars(chosen_match);
@@ -1158,9 +1159,9 @@
if ((int)(len_found - match_pfx_len + command_len) < S.maxsize) {
int pos;
/* save tail */
- strcpy(matchBuf, &command_ps[cursor]);
+ strcpy(match_buf, &command_ps[cursor]);
/* add match and tail */
- sprintf(&command_ps[cursor], "%s%s", chosen_match + match_pfx_len, matchBuf);
+ sprintf(&command_ps[cursor], "%s%s", chosen_match + match_pfx_len, match_buf);
command_len = strlen(command_ps);
/* new pos */
pos = cursor + len_found - match_pfx_len;
@@ -1169,19 +1170,20 @@
}
#else
{
- char command[MAX_LINELEN];
- int len = save_string(command, sizeof(command));
+ /* Use 2nd half of match_buf as scratch space - see (**) */
+ char *command = match_buf + MAX_LINELEN;
+ int len = save_string(command, MAX_LINELEN);
/* Have space to place the match? */
/* cursor_mb + (len_found - match_pfx_len) + (len - cursor_mb) */
if ((int)(len_found - match_pfx_len + len) < MAX_LINELEN) {
int pos;
/* save tail */
- strcpy(matchBuf, &command[cursor_mb]);
+ strcpy(match_buf, &command[cursor_mb]);
/* where do we want to have cursor after all? */
strcpy(&command[cursor_mb], chosen_match + match_pfx_len);
len = load_string(command, S.maxsize);
/* add match and tail */
- sprintf(&command[cursor_mb], "%s%s", chosen_match + match_pfx_len, matchBuf);
+ sprintf(&command[cursor_mb], "%s%s", chosen_match + match_pfx_len, match_buf);
command_len = load_string(command, S.maxsize);
/* write out the matched command */
/* paranoia: load_string can return 0 on conv error,
@@ -1191,8 +1193,9 @@
}
}
#endif
+ ret:
free(chosen_match);
-#undef matchBuf
+ free(match_buf);
}
#endif /* FEATURE_TAB_COMPLETION */