lineedit: remove pos_buf[] array (up to 16k!); fix compat bugs

pos_buf is a strange hack, easy to do without it.
This also allows lines >32k long to be handled.
Also simplified match prefix generations and made behavior more like bash.

function                                             old     new   delta
remove_chunk                                           -      43     +43
collapse_pos                                          79       -     -79
build_match_prefix                                   804     579    -225
------------------------------------------------------------------------------
(add/remove: 1/1 grow/shrink: 0/1 up/down: 43/-304)          Total: -261 bytes

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>

diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index e40917f..fff5c1a 100644 (file)
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -99,7 +99,6 @@ static bool BB_ispunct(CHAR_T c) { return ((unsigned)c < 256 && ispunct(c)); }
 
 
 enum {
-       /* We use int16_t for positions, need to limit line len */
        MAX_LINELEN = CONFIG_FEATURE_EDITING_MAX_LEN < 0x7ff0
                      ? CONFIG_FEATURE_EDITING_MAX_LEN
                      : 0x7ff0
@@ -156,7 +155,6 @@ struct lineedit_statics {
 #if ENABLE_FEATURE_TAB_COMPLETION
        char input_tab__matchBuf[MAX_LINELEN];
        int16_t find_match__int_buf[MAX_LINELEN + 1]; /* need to have 9 bits at least */
-       int16_t find_match__pos_buf[MAX_LINELEN + 1];
 #endif
 };
 
@@ -824,15 +822,16 @@ static NOINLINE unsigned complete_cmd_dir_file(const char *command, int type)
  */
 #define QUOT (UCHAR_MAX+1)
 #define int_buf (S.find_match__int_buf)
-#define pos_buf (S.find_match__pos_buf)
 #define dbg_bmp 0
-static void collapse_pos(int beg, int end)
+static void remove_chunk(int beg, int end)
 {
        /* beg must be <= end */
        if (beg == end)
                return;
-       memmove(int_buf+beg, int_buf+end, (MAX_LINELEN+1-end) * sizeof(int_buf[0]));
-       memmove(pos_buf+beg, pos_buf+end, (MAX_LINELEN+1-end) * sizeof(pos_buf[0]));
+
+       while ((int_buf[beg] = int_buf[end]) != 0)
+               beg++, end++;
+
        if (dbg_bmp) {
                int i;
                for (i = 0; int_buf[i]; i++)
@@ -846,42 +845,39 @@ static NOINLINE int build_match_prefix(char *matchBuf)
        int command_mode;
 /*     Were local, but it used too much stack */
 /*     int16_t int_buf[MAX_LINELEN + 1]; */
-/*     int16_t pos_buf[MAX_LINELEN + 1]; */
 
        if (dbg_bmp) printf("\n%s\n", matchBuf);
 
-       for (i = 0;; i++) {
-               int_buf[i] = (unsigned char)matchBuf[i];
-               if (int_buf[i] == 0) {
-                       pos_buf[i] = -1; /* end-of-line indicator */
-                       break;
-               }
-               pos_buf[i] = i;
-       }
+       i = 0;
+       while ((int_buf[i] = (unsigned char)matchBuf[i]) != '\0')
+               i++;
 
        /* Mark every \c as "quoted c" */
        for (i = j = 0; matchBuf[i]; i++, j++) {
                if (matchBuf[i] == '\\') {
-                       collapse_pos(j, j + 1);
+                       remove_chunk(j, j + 1);
                        int_buf[j] |= QUOT;
                        i++;
                }
        }
-       /* Quote-mark "chars" and 'chars' */
+       /* Quote-mark "chars" and 'chars', drop delimiters */
        {
                int in_quote = 0;
-               for (i = 0; int_buf[i]; i++) {
+               i = 0;
+               while (int_buf[i]) {
                        int cur = int_buf[i];
+                       if (!cur)
+                               break;
                        if (cur == '\'' || cur == '"') {
-                               if (!in_quote)
-                                       in_quote = cur;
-                               else if (cur == in_quote)
-                                       in_quote = 0;
-                               else
-                                       int_buf[i] |= QUOT;
-                       } else if (in_quote && cur != '$') {
-                               int_buf[i] |= QUOT;
+                               if (!in_quote || (cur == in_quote)) {
+                                       in_quote ^= cur;
+                                       remove_chunk(i, i + 1);
+                                       continue;
+                               }
                        }
+                       if (in_quote)
+                               int_buf[i] = cur | QUOT;
+                       i++;
                }
        }
 
@@ -898,53 +894,39 @@ static NOINLINE int build_match_prefix(char *matchBuf)
                        } else if (cur == '|' && prev == '>') {
                                continue;
                        }
-                       collapse_pos(0, i + 1 + (cur == int_buf[i + 1]));
+                       remove_chunk(0, i + 1 + (cur == int_buf[i + 1]));
                        i = -1;  /* back to square 1 */
                }
        }
        /* Remove all `cmd` */
-//BUG: `cmd` should count as a word: `cmd` c<tab> should search for files c*, not commands c*
        for (i = 0; int_buf[i]; i++) {
                if (int_buf[i] == '`') {
                        for (j = i + 1; int_buf[j]; j++) {
                                if (int_buf[j] == '`') {
-                                       collapse_pos(i, j + 1);
+                                       /* `cmd` should count as a word:
+                                        * `cmd` c<tab> should search for files c*,
+                                        * not commands c*. Therefore we don't drop
+                                        * `cmd` entirely, we replace it with single `.
+                                        */
+                                       remove_chunk(i, j);
                                        goto next;
                                }
                        }
                        /* No closing ` - command mode, remove all up to ` */
-                       collapse_pos(0, i + 1);
+                       remove_chunk(0, i + 1);
                        break;
- next:
-                       i--;  /* hack increment */
+ next: ;
                }
        }
 
-       /* Remove (command...(command...)...) and {command...{command...}...} */
-       {
-               int paren_lvl = 0;
-               int curly_lvl = 0;
-               for (i = 0; int_buf[i]; i++) {
-                       if (int_buf[i] == '(' || int_buf[i] == '{') {
-                               if (int_buf[i] == '(')
-                                       paren_lvl++;
-                               else
-                                       curly_lvl++;
-                               collapse_pos(0, i + 1);
-                               i = -1;  /* hack increment */
-                       }
-               }
-               for (i = 0; pos_buf[i] >= 0 && (paren_lvl > 0 || curly_lvl > 0); i++) {
-                       if ((int_buf[i] == ')' && paren_lvl > 0)
-                        || (int_buf[i] == '}' && curly_lvl > 0)
-                       ) {
-                               if (int_buf[i] == ')')
-                                       paren_lvl--;
-                               else
-                                       curly_lvl--;
-                               collapse_pos(0, i + 1);
-                               i = -1;  /* hack increment */
-                       }
+       /* Remove "cmd (" and "cmd {"
+        * Example: "if { c<tab>"
+        * In this example, c should be matched as command pfx.
+        */
+       for (i = 0; int_buf[i]; i++) {
+               if (int_buf[i] == '(' || int_buf[i] == '{') {
+                       remove_chunk(0, i + 1);
+                       i = -1;  /* hack increment */
                }
        }
 
@@ -952,7 +934,7 @@ static NOINLINE int build_match_prefix(char *matchBuf)
        for (i = 0; int_buf[i]; i++)
                if (int_buf[i] != ' ')
                        break;
-       collapse_pos(0, i);
+       remove_chunk(0, i);
 
        /* Determine completion mode */
        command_mode = FIND_EXE_ONLY;
@@ -960,9 +942,9 @@ static NOINLINE int build_match_prefix(char *matchBuf)
                if (int_buf[i] == ' ' || int_buf[i] == '<' || int_buf[i] == '>') {
                        if (int_buf[i] == ' '
                         && command_mode == FIND_EXE_ONLY
-                        && matchBuf[pos_buf[0]] == 'c'
-                        && matchBuf[pos_buf[1]] == 'd'
-//BUG: must check "cd ", not "cd"
+                        && (char)int_buf[0] == 'c'
+                        && (char)int_buf[1] == 'd'
+                        && i == 2 /* -> int_buf[2] == ' ' */
                        ) {
                                command_mode = FIND_DIR_ONLY;
                        } else {
@@ -979,36 +961,20 @@ static NOINLINE int build_match_prefix(char *matchBuf)
        for (--i; i >= 0; i--) {
                int cur = int_buf[i];
                if (cur == ' ' || cur == '<' || cur == '>' || cur == '|' || cur == '&') {
-                       collapse_pos(0, i + 1);
+                       remove_chunk(0, i + 1);
                        break;
                }
        }
-       /* Skip all leading unquoted ' or " */
-//BUG: bash doesn't do this
-       for (i = 0; int_buf[i] == '\'' || int_buf[i] == '"'; i++)
-               continue;
-       /* Skip quoted or unquoted // or /~ */
-//BUG: bash doesn't do this
-       while ((char)int_buf[i] == '/'
-        && ((char)int_buf[i+1] == '/' || (char)int_buf[i+1] == '~')
-       ) {
-               i++;
-       }
 
-       /* set only match and destroy quotes */
-       {
-               int pos = 0;
-               for (j = 0; pos_buf[i] >= 0; i++) {
-                       matchBuf[j++] = matchBuf[pos_buf[i]];
-                       pos = pos_buf[i] + 1;
-               }
-               matchBuf[j] = '\0';
-       }
+       /* Store only match prefix */
+       i = 0;
+       while ((matchBuf[i] = int_buf[i]) != '\0')
+               i++;
+       if (dbg_bmp) printf("final matchBuf:'%s'\n", matchBuf);
 
        return command_mode;
 }
 #undef int_buf
-#undef pos_buf
 
 /*
  * Display by column (original idea from ls applet,