lineedit: stop using both data/bss and tons of stack.
authorvda <vda@69ca8d6d-28ef-0310-b511-8ec308f3f277>
Sat, 10 Nov 2007 01:35:47 +0000 (01:35 +0000)
committervda <vda@69ca8d6d-28ef-0310-b511-8ec308f3f277>
Sat, 10 Nov 2007 01:35:47 +0000 (01:35 +0000)
stack usage was ~10 kb!
unfortunately, noticeable code size growth:
   text    data     bss     dec     hex filename
   9252      12     181    9445    24e5 busybox.t7/libbb/lineedit.o
   9714       4       0    9718    25f6 busybox.t8/libbb/lineedit.o

git-svn-id: svn://busybox.net/trunk/busybox@20400 69ca8d6d-28ef-0310-b511-8ec308f3f277

libbb/lineedit.c

index f65e852..4d33834 100644 (file)
@@ -41,7 +41,6 @@
 #define ENABLE_FEATURE_TAB_COMPLETION 0
 #define ENABLE_FEATURE_USERNAME_COMPLETION 0
 #define ENABLE_FEATURE_NONPRINTABLE_INVERSE_PUT 0
-#define ENABLE_FEATURE_CLEAN_UP 0
 
 #endif  /* TEST */
 
 #endif
 
 #define ENABLE_FEATURE_GETUSERNAME_AND_HOMEDIR \
-(ENABLE_FEATURE_USERNAME_COMPLETION || ENABLE_FEATURE_EDITING_FANCY_PROMPT)
+       (ENABLE_FEATURE_USERNAME_COMPLETION || ENABLE_FEATURE_EDITING_FANCY_PROMPT)
+#define USE_FEATURE_GETUSERNAME_AND_HOMEDIR(...)
+#if ENABLE_FEATURE_GETUSERNAME_AND_HOMEDIR
+#undef USE_FEATURE_GETUSERNAME_AND_HOMEDIR
+#define USE_FEATURE_GETUSERNAME_AND_HOMEDIR(...) __VA_ARGS__
+#endif
 
-enum { MAX_LINELEN = CONFIG_FEATURE_EDITING_MAX_LEN };
+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
+};
+
+#if ENABLE_FEATURE_GETUSERNAME_AND_HOMEDIR
+static const char null_str[] ALIGN1 = "";
+#endif
 
-static line_input_t *state;
+/* We try to minimize both static and stack usage. */
+struct statics {
+       line_input_t *state;
 
-static struct termios initial_settings, new_settings;
+       volatile unsigned cmdedit_termw; /* = 80; */ /* actual terminal width */
+       sighandler_t previous_SIGWINCH_handler;
 
-static volatile unsigned cmdedit_termw = 80;        /* actual terminal width */
 
-static int cmdedit_x;           /* real x terminal position */
-static int cmdedit_y;           /* pseudoreal y terminal position */
-static int cmdedit_prmt_len;    /* length of prompt (without colors etc) */
+       int cmdedit_x;           /* real x terminal position */
+       int cmdedit_y;           /* pseudoreal y terminal position */
+       int cmdedit_prmt_len;    /* length of prompt (without colors etc) */
 
-static unsigned cursor;
-static unsigned command_len;
-static char *command_ps;
-static const char *cmdedit_prompt;
+       unsigned cursor;
+       unsigned command_len;
+       char *command_ps;
 
+       const char *cmdedit_prompt;
 #if ENABLE_FEATURE_EDITING_FANCY_PROMPT
-static char *hostname_buf;
-static int num_ok_lines = 1;
+       char *hostname_buf;
+       int num_ok_lines; /* = 1; */
+#endif
+
+#if ENABLE_FEATURE_GETUSERNAME_AND_HOMEDIR
+       char *user_buf;
+       char *home_pwd_buf; /* = (char*)null_str; */
+#endif
+
+#if ENABLE_FEATURE_TAB_COMPLETION
+       char **matches;
+       unsigned num_matches;
 #endif
 
+#if ENABLE_FEATURE_EDITING_VI
+#define DELBUFSIZ 128
+       char *delptr;
+       smallint newdelflag;     /* whether delbuf should be reused yet */
+       char delbuf[DELBUFSIZ];  /* a place to store deleted characters */
+#endif
+
+       /* Formerly these were big buffers on stack: */
+#if ENABLE_FEATURE_TAB_COMPLETION
+       char exe_n_cwd_tab_completion__dirbuf[MAX_LINELEN];
+       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
+};
+
+static struct statics *const ptr_to_statics __attribute__ ((section (".data")));
+
+#define S (*ptr_to_statics)
+#define state            (S.state           )
+#define cmdedit_termw    (S.cmdedit_termw   )
+#define previous_SIGWINCH_handler (S.previous_SIGWINCH_handler)
+#define cmdedit_x        (S.cmdedit_x       )
+#define cmdedit_y        (S.cmdedit_y       )
+#define cmdedit_prmt_len (S.cmdedit_prmt_len)
+#define cursor           (S.cursor          )
+#define command_len      (S.command_len     )
+#define command_ps       (S.command_ps      )
+#define cmdedit_prompt   (S.cmdedit_prompt  )
+#define hostname_buf     (S.hostname_buf    )
+#define num_ok_lines     (S.num_ok_lines    )
+#define user_buf         (S.user_buf        ) 
+#define home_pwd_buf     (S.home_pwd_buf    )
+#define matches          (S.matches         )
+#define num_matches      (S.num_matches     )
+#define delptr           (S.delptr          )
+#define newdelflag       (S.newdelflag      )
+#define delbuf           (S.delbuf          )
+
+#define INIT_S() do { \
+       (*(struct statics**)&ptr_to_statics) = xzalloc(sizeof(S)); \
+       cmdedit_termw = 80; \
+       USE_FEATURE_EDITING_FANCY_PROMPT(num_ok_lines = 1;) \
+       USE_FEATURE_GETUSERNAME_AND_HOMEDIR(home_pwd_buf = (char*)null_str;) \
+} while (0)
+static void deinit_S(void)
+{
+#if ENABLE_FEATURE_EDITING_FANCY_PROMPT
+       free(hostname_buf);
+       /* This one is allocated only if FANCY_PROMPT is on
+        * (otherwise it points to verbatim prompt (NOT malloced) */
+       free((char*)cmdedit_prompt);
+#endif
 #if ENABLE_FEATURE_GETUSERNAME_AND_HOMEDIR
-static const char null_str[] = "";
-static char *user_buf;
-static char *home_pwd_buf = (char*)null_str;
+       free(user_buf);
+       if (home_pwd_buf != null_str)
+               free(home_pwd_buf);
 #endif
+       free(ptr_to_statics);
+}
+#define DEINIT_S() deinit_S()
 
 /* Put 'command_ps[cursor]', cursor++.
  * Advance cursor on screen. If we reached right margin, scroll text up
@@ -110,8 +191,7 @@ static void cmdedit_set_out_char(int next_char)
        } else
 #endif
        {
-               if (initial_settings.c_lflag & ECHO)
-                       bb_putchar(c);
+               bb_putchar(c);
        }
        if (++cmdedit_x >= cmdedit_termw) {
                /* terminal is scrolled down */
@@ -204,13 +284,6 @@ static void redraw(int y, int back_cursor)
        input_backward(back_cursor);
 }
 
-#if ENABLE_FEATURE_EDITING_VI
-#define DELBUFSIZ 128
-static char *delbuf;  /* a (malloced) place to store deleted characters */
-static char *delp;
-static char newdelflag;      /* whether delbuf should be reused yet */
-#endif
-
 /* Delete the char in front of the cursor, optionally saving it
  * for later putback */
 static void input_delete(int save)
@@ -223,14 +296,11 @@ static void input_delete(int save)
 #if ENABLE_FEATURE_EDITING_VI
        if (save) {
                if (newdelflag) {
-                       if (!delbuf)
-                               delbuf = malloc(DELBUFSIZ);
-                       /* safe if malloc fails */
-                       delp = delbuf;
+                       delptr = delbuf;
                        newdelflag = 0;
                }
-               if (delbuf && (delp - delbuf < DELBUFSIZ))
-                       *delp++ = command_ps[j];
+               if ((delptr - delbuf) < DELBUFSIZ)
+                       *delptr++ = command_ps[j];
        }
 #endif
 
@@ -245,7 +315,7 @@ static void input_delete(int save)
 static void put(void)
 {
        int ocursor;
-       int j = delp - delbuf;
+       int j = delptr - delbuf;
 
        if (j == 0)
                return;
@@ -275,12 +345,8 @@ static void input_forward(void)
                cmdedit_set_out_char(command_ps[cursor + 1]);
 }
 
-
 #if ENABLE_FEATURE_TAB_COMPLETION
 
-static char **matches;
-static unsigned num_matches;
-
 static void free_tab_completion_data(void)
 {
        if (matches) {
@@ -329,11 +395,8 @@ static void username_tab_completion(char *ud, char *with_shash_flg)
                }
                if (home) {
                        if ((userlen + strlen(home) + 1) < MAX_LINELEN) {
-                               char temp2[MAX_LINELEN];     /* argument size */
-
                                /* /home/user/... */
-                               sprintf(temp2, "%s%s", home, ud);
-                               strcpy(sav_ud, temp2);
+                               sprintf(sav_ud, "%s%s", home, ud);
                        }
                }
        } else {
@@ -411,7 +474,6 @@ static void exe_n_cwd_tab_completion(char *command, int type)
 {
        DIR *dir;
        struct dirent *next;
-       char dirbuf[MAX_LINELEN];
        struct stat st;
        char *path1[1];
        char **paths = path1;
@@ -419,6 +481,8 @@ static void exe_n_cwd_tab_completion(char *command, int type)
        int i;
        char *found;
        char *pfind = strrchr(command, '/');
+/*     char dirbuf[MAX_LINELEN]; */
+#define dirbuf (S.exe_n_cwd_tab_completion__dirbuf)
 
        npaths = 1;
        path1[0] = (char*)".";
@@ -492,21 +556,25 @@ static void exe_n_cwd_tab_completion(char *command, int type)
                free(paths[0]);                 /* allocated memory only in first member */
                free(paths);
        }
+#undef dirbuf
 }
 
 #define QUOT (UCHAR_MAX+1)
 
-#define collapse_pos(is, in) { \
-       memmove(int_buf+(is), int_buf+(in), (MAX_LINELEN+1-(is)-(in))*sizeof(int)); \
-       memmove(pos_buf+(is), pos_buf+(in), (MAX_LINELEN+1-(is)-(in))*sizeof(int)); }
+#define collapse_pos(is, in) do { \
+       memmove(int_buf+(is), int_buf+(in), (MAX_LINELEN+1-(is)-(in)) * sizeof(pos_buf[0])); \
+       memmove(pos_buf+(is), pos_buf+(in), (MAX_LINELEN+1-(is)-(in)) * sizeof(pos_buf[0])); \
+} while (0)
 
 static int find_match(char *matchBuf, int *len_with_quotes)
 {
        int i, j;
        int command_mode;
        int c, c2;
-       int int_buf[MAX_LINELEN + 1];
-       int pos_buf[MAX_LINELEN + 1];
+/*     int16_t int_buf[MAX_LINELEN + 1]; */
+/*     int16_t pos_buf[MAX_LINELEN + 1]; */
+#define int_buf (S.find_match__int_buf)
+#define pos_buf (S.find_match__pos_buf)
 
        /* set to integer dimension characters and own positions */
        for (i = 0;; i++) {
@@ -622,8 +690,8 @@ static int find_match(char *matchBuf, int *len_with_quotes)
        for (i = 0; int_buf[i]; i++)
                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'
+                        && matchBuf[pos_buf[0]] == 'c'
+                        && matchBuf[pos_buf[1]] == 'd'
                        ) {
                                command_mode = FIND_DIR_ONLY;
                        } else {
@@ -657,11 +725,13 @@ static int find_match(char *matchBuf, int *len_with_quotes)
                matchBuf[c++] = matchBuf[pos_buf[i]];
                j = pos_buf[i] + 1;
        }
-       matchBuf[c] = 0;
+       matchBuf[c] = '\0';
        /* old length matchBuf with quotes symbols */
        *len_with_quotes = j ? j - pos_buf[0] : 0;
 
        return command_mode;
+#undef int_buf
+#undef pos_buf
 }
 
 /*
@@ -724,7 +794,7 @@ static int match_compare(const void *a, const void *b)
 }
 
 /* Do TAB completion */
-static void input_tab(int *lastWasTab)
+static void input_tab(smallint *lastWasTab)
 {
        if (!(state->flags & TAB_COMPLETION))
                return;
@@ -732,7 +802,8 @@ static void input_tab(int *lastWasTab)
        if (!*lastWasTab) {
                char *tmp, *tmp1;
                int len_found;
-               char matchBuf[MAX_LINELEN];
+/*             char matchBuf[MAX_LINELEN]; */
+#define matchBuf (S.input_tab__matchBuf)
                int find_type;
                int recalc_pos;
 
@@ -782,7 +853,6 @@ static void input_tab(int *lastWasTab)
                        if (!matches)
                                return;         /* not found */
                        /* find minimal match */
-               // ash: yet another failure in trying to achieve "we don't die on OOM"
                        tmp1 = xstrdup(matches[0]);
                        for (tmp = tmp1; *tmp; tmp++)
                                for (len_found = 1; len_found < num_matches; len_found++)
@@ -811,7 +881,7 @@ static void input_tab(int *lastWasTab)
                /* have space to placed match? */
                if ((len_found - strlen(matchBuf) + command_len) < MAX_LINELEN) {
                        /* before word for match   */
-                       command_ps[cursor - recalc_pos] = 0;
+                       command_ps[cursor - recalc_pos] = '\0';
                        /* save   tail line        */
                        strcpy(matchBuf, command_ps + cursor);
                        /* add    match            */
@@ -828,6 +898,7 @@ static void input_tab(int *lastWasTab)
                        redraw(cmdedit_y, command_len - recalc_pos);
                }
                free(tmp);
+#undef matchBuf
        } else {
                /* Ok -- the last char was a TAB.  Since they
                 * just hit TAB again, print a list of all the
@@ -843,8 +914,6 @@ static void input_tab(int *lastWasTab)
        }
 }
 
-#else
-#define input_tab(a) ((void)0)
 #endif  /* FEATURE_COMMAND_TAB_COMPLETION */
 
 
@@ -1079,14 +1148,14 @@ vi_back_motion(char *command)
  */
 
 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
-static void parse_prompt(const char *prmt_ptr)
+static void parse_and_put_prompt(const char *prmt_ptr)
 {
        cmdedit_prompt = prmt_ptr;
        cmdedit_prmt_len = strlen(prmt_ptr);
        put_prompt();
 }
 #else
-static void parse_prompt(const char *prmt_ptr)
+static void parse_and_put_prompt(const char *prmt_ptr)
 {
        int prmt_len = 0;
        size_t cur_prmt_len = 0;
@@ -1114,7 +1183,7 @@ static void parse_prompt(const char *prmt_ptr)
 
                        c = bb_process_escape_sequence(&prmt_ptr);
                        if (prmt_ptr == cp) {
-                               if (*cp == 0)
+                               if (*cp == '\0')
                                        break;
                                c = *prmt_ptr++;
                                switch (c) {
@@ -1147,7 +1216,7 @@ static void parse_prompt(const char *prmt_ptr)
                                        if (l != 0
                                         && strncmp(home_pwd_buf, pbuf, l) == 0
                                         && (pbuf[l]=='/' || pbuf[l]=='\0')
-                                        && strlen(pwd_buf+l)<PATH_MAX
+                                        && strlen(pwd_buf+l) < PATH_MAX
                                        ) {
                                                pbuf = buf2;
                                                *pbuf = '~';
@@ -1188,7 +1257,7 @@ static void parse_prompt(const char *prmt_ptr)
                                        break;
                                case '[': case ']':
                                        if (c == flg_not_length) {
-                                               flg_not_length = flg_not_length == '[' ? ']' : '[';
+                                               flg_not_length = (flg_not_length == '[' ? ']' : '[');
                                                continue;
                                        }
                                        break;
@@ -1210,11 +1279,6 @@ static void parse_prompt(const char *prmt_ptr)
 }
 #endif
 
-#define setTermSettings(fd, argp) tcsetattr(fd, TCSANOW, argp)
-#define getTermSettings(fd, argp) tcgetattr(fd, argp);
-
-static sighandler_t previous_SIGWINCH_handler;
-
 static void cmdedit_setwidth(unsigned w, int redraw_flg)
 {
        cmdedit_termw = w;
@@ -1261,7 +1325,9 @@ static void win_changed(int nsig)
  */
 int read_line_input(const char *prompt, char *command, int maxsize, line_input_t *st)
 {
-       int lastWasTab = FALSE;
+#if ENABLE_FEATURE_TAB_COMPLETION
+       smallint lastWasTab = FALSE;
+#endif
        unsigned int ic;
        unsigned char c;
        smallint break_out = 0;
@@ -1269,14 +1335,22 @@ int read_line_input(const char *prompt, char *command, int maxsize, line_input_t
        smallint vi_cmdmode = 0;
        smalluint prevc;
 #endif
+       struct termios initial_settings;
+       struct termios new_settings;
 
-       getTermSettings(0, (void *) &initial_settings);
-       /* Happens when e.g. stty -echo was run before */
-       if (!(initial_settings.c_lflag & ECHO)) {
-               parse_prompt(prompt);
+       INIT_S();
+
+       if (tcgetattr(STDIN_FILENO, &initial_settings) < 0
+        || !(initial_settings.c_lflag & ECHO)
+       ) {
+               /* Happens when e.g. stty -echo was run before */
+               int len;
+               parse_and_put_prompt(prompt);
                fflush(stdout);
                fgets(command, maxsize, stdin);
-               return strlen(command);
+               len = strlen(command);
+               DEINIT_S();
+               return len;
        }
 
 // FIXME: audit & improve this
@@ -1296,7 +1370,7 @@ int read_line_input(const char *prompt, char *command, int maxsize, line_input_t
        command_ps = command;
        command[0] = '\0';
 
-       memcpy(&new_settings, &initial_settings, sizeof(new_settings));
+       new_settings = initial_settings;
        new_settings.c_lflag &= ~ICANON;        /* unbuffered input */
        /* Turn off echoing and CTRL-C, so we can trap it */
        new_settings.c_lflag &= ~(ECHO | ECHONL | ISIG);
@@ -1308,7 +1382,7 @@ int read_line_input(const char *prompt, char *command, int maxsize, line_input_t
 #define _POSIX_VDISABLE '\0'
 #endif
        new_settings.c_cc[VINTR] = _POSIX_VDISABLE;
-       setTermSettings(0, (void *) &new_settings);
+       tcsetattr(STDIN_FILENO, TCSANOW, &new_settings);
 
        /* Now initialize things */
        previous_SIGWINCH_handler = signal(SIGWINCH, win_changed);
@@ -1319,11 +1393,6 @@ int read_line_input(const char *prompt, char *command, int maxsize, line_input_t
 
                entry = getpwuid(geteuid());
                if (entry) {
-                       /* If we enter read_line_input for the Nth time,
-                        * they may be already allocated! Need to free. */
-                       free(user_buf);
-                       if (home_pwd_buf != null_str)
-                               free(home_pwd_buf);
                        user_buf = xstrdup(entry->pw_name);
                        home_pwd_buf = xstrdup(entry->pw_dir);
                        /* They are not freed on exit (too small to bother) */
@@ -1331,12 +1400,12 @@ int read_line_input(const char *prompt, char *command, int maxsize, line_input_t
        }
 #endif
        /* Print out the command prompt */
-       parse_prompt(prompt);
+       parse_and_put_prompt(prompt);
 
        while (1) {
                fflush(stdout);
 
-               if (safe_read(0, &c, 1) < 1) {
+               if (safe_read(STDIN_FILENO, &c, 1) < 1) {
                        /* if we can't read input then exit */
                        goto prepare_to_die;
                }
@@ -1411,9 +1480,11 @@ int read_line_input(const char *prompt, char *command, int maxsize, line_input_t
                        input_backspace();
                        break;
 
+#if ENABLE_FEATURE_TAB_COMPLETION
                case '\t':
                        input_tab(&lastWasTab);
                        break;
+#endif
 
 #if ENABLE_FEATURE_EDITING_FANCY_KEYS
                case CTRL('K'):
@@ -1526,7 +1597,7 @@ int read_line_input(const char *prompt, char *command, int maxsize, line_input_t
                        int nc, sc;
                        sc = cursor;
                        prevc = ic;
-                       if (safe_read(0, &c, 1) < 1)
+                       if (safe_read(STDIN_FILENO, &c, 1) < 1)
                                goto prepare_to_die;
                        if (c == (prevc & 0xff)) {
                                /* "cc", "dd" */
@@ -1587,7 +1658,7 @@ int read_line_input(const char *prompt, char *command, int maxsize, line_input_t
                        put();
                        break;
                case 'r'|vbit:
-                       if (safe_read(0, &c, 1) < 1)
+                       if (safe_read(STDIN_FILENO, &c, 1) < 1)
                                goto prepare_to_die;
                        if (c == 0)
                                beep();
@@ -1610,19 +1681,19 @@ int read_line_input(const char *prompt, char *command, int maxsize, line_input_t
                        }
 #endif
                        /* escape sequence follows */
-                       if (safe_read(0, &c, 1) < 1)
+                       if (safe_read(STDIN_FILENO, &c, 1) < 1)
                                goto prepare_to_die;
                        /* different vt100 emulations */
                        if (c == '[' || c == 'O') {
                vi_case('['|vbit:)
                vi_case('O'|vbit:)
-                               if (safe_read(0, &c, 1) < 1)
+                               if (safe_read(STDIN_FILENO, &c, 1) < 1)
                                        goto prepare_to_die;
                        }
                        if (c >= '1' && c <= '9') {
                                unsigned char dummy;
 
-                               if (safe_read(0, &dummy, 1) < 1)
+                               if (safe_read(STDIN_FILENO, &dummy, 1) < 1)
                                        goto prepare_to_die;
                                if (dummy != '~')
                                        c = '\0';
@@ -1687,7 +1758,7 @@ int read_line_input(const char *prompt, char *command, int maxsize, line_input_t
 #if ENABLE_FEATURE_NONPRINTABLE_INVERSE_PUT
                        /* Control-V -- Add non-printable symbol */
                        if (c == CTRL('V')) {
-                               if (safe_read(0, &c, 1) < 1)
+                               if (safe_read(STDIN_FILENO, &c, 1) < 1)
                                        goto prepare_to_die;
                                if (c == 0) {
                                        beep();
@@ -1727,8 +1798,10 @@ int read_line_input(const char *prompt, char *command, int maxsize, line_input_t
                if (break_out)                  /* Enter is the command terminator, no more input. */
                        break;
 
+#if ENABLE_FEATURE_TAB_COMPLETION
                if (c != '\t')
                        lastWasTab = FALSE;
+#endif
        }
 
        if (command_len > 0)
@@ -1739,18 +1812,18 @@ int read_line_input(const char *prompt, char *command, int maxsize, line_input_t
                command[command_len] = '\0';
        }
 
-#if ENABLE_FEATURE_CLEAN_UP && ENABLE_FEATURE_TAB_COMPLETION
+#if ENABLE_FEATURE_TAB_COMPLETION
        free_tab_completion_data();
 #endif
 
-#if ENABLE_FEATURE_EDITING_FANCY_PROMPT
-       free((char*)cmdedit_prompt);
-#endif
        /* restore initial_settings */
-       setTermSettings(STDIN_FILENO, (void *) &initial_settings);
+       tcsetattr(STDIN_FILENO, TCSANOW, &initial_settings);
        /* restore SIGWINCH handler */
        signal(SIGWINCH, previous_SIGWINCH_handler);
        fflush(stdout);
+
+       DEINIT_S();
+
        return command_len;
 }