ash: allocate line editing structure only if needed

function                                             old     new   delta
optschanged                                           91     128     +37
historycmd                                            13      17      +4
setcmd                                                80      78      -2
ash_main                                            1167    1150     -17
options                                              576     552     -24
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/3 up/down: 41/-43)             Total: -2 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/shell/ash.c b/shell/ash.c
index 924e17f32d3e9f7d42cea80288e02f766d1853f1..c8857366c38cda2a4d591b96e648e67492ef1d79 100644 (file)
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -315,9 +315,16 @@ static const char *const optletters_optnames[] = {
        "e"   "errexit",
        "f"   "noglob",
        "I"   "ignoreeof",
+/* The below allows this invocation:
+ * ash -c 'set -i; echo $-; sleep 5; echo $-'
+ * to be ^C-ed and get to interactive ash prompt.
+ * bash does not support this "set -i". bash also has no
+ * "set -o interactive".
+ */
        "i"   "interactive",
        "m"   "monitor",
        "n"   "noexec",
+/* Ditto: bash has no "set -s" and "set -o stdin" */
        "s"   "stdin",
        "x"   "xtrace",
        "v"   "verbose",
@@ -334,10 +341,25 @@ static const char *const optletters_optnames[] = {
        ,"\0"  "debug"
 #endif
 };
+//bash 4.4.23 also has these opts (with these defaults):
+//braceexpand           on
+//emacs                 on
+//errtrace              off
+//functrace             off
+//hashall               on
+//histexpand            off
+//history               on
+//interactive-comments  on
+//keyword               off
+//onecmd                off
+//physical              off
+//posix                 off
+//privileged            off
 
 #define optletters(n)  optletters_optnames[n][0]
 #define optnames(n)   (optletters_optnames[n] + 1)
 
+
 enum { NOPTS = ARRAY_SIZE(optletters_optnames) };
 
 
@@ -9514,8 +9536,8 @@ setinteractive(int on)
        setsignal(SIGINT);
        setsignal(SIGQUIT);
        setsignal(SIGTERM);
-#if !ENABLE_FEATURE_SH_EXTRA_QUIET
        if (is_interactive > 1) {
+#if !ENABLE_FEATURE_SH_EXTRA_QUIET
                /* Looks like they want an interactive shell */
                static smallint did_banner;
 
@@ -9529,8 +9551,12 @@ setinteractive(int on)
                        );
                        did_banner = 1;
                }
-       }
 #endif
+#if ENABLE_FEATURE_EDITING
+               if (!line_input_state)
+                       line_input_state = new_line_input_t(FOR_SHELL | WITH_PATH_LOOKUP);
+#endif
+       }
 }
 
 static void
@@ -9542,10 +9568,12 @@ optschanged(void)
        setinteractive(iflag);
        setjobctl(mflag);
 #if ENABLE_FEATURE_EDITING_VI
-       if (viflag)
-               line_input_state->flags |= VI_MODE;
-       else
-               line_input_state->flags &= ~VI_MODE;
+       if (line_input_state) {
+               if (viflag)
+                       line_input_state->flags |= VI_MODE;
+               else
+                       line_input_state->flags &= ~VI_MODE;
+       }
 #else
        viflag = 0; /* forcibly keep the option off */
 #endif
@@ -10519,13 +10547,11 @@ preadfd(void)
        else {
 # if ENABLE_ASH_IDLE_TIMEOUT
                int timeout = -1;
-               if (iflag) {
-                       const char *tmout_var = lookupvar("TMOUT");
-                       if (tmout_var) {
-                               timeout = atoi(tmout_var) * 1000;
-                               if (timeout <= 0)
-                                       timeout = -1;
-                       }
+               const char *tmout_var = lookupvar("TMOUT");
+               if (tmout_var) {
+                       timeout = atoi(tmout_var) * 1000;
+                       if (timeout <= 0)
+                               timeout = -1;
                }
                line_input_state->timeout = timeout;
 # endif
@@ -11086,14 +11112,17 @@ setoption(int flag, int val)
        ash_msg_and_raise_error("illegal option %c%c", val ? '-' : '+', flag);
        /* NOTREACHED */
 }
+/* If login_sh is not NULL, we are called to parse command line opts,
+ * not "set -opts"
+ */
 static int
-options(int cmdline, int *login_sh)
+options(int *login_sh)
 {
        char *p;
        int val;
        int c;
 
-       if (cmdline)
+       if (login_sh)
                minusc = NULL;
        while ((p = *argptr) != NULL) {
                c = *p++;
@@ -11104,7 +11133,7 @@ options(int cmdline, int *login_sh)
                if (c == '-') {
                        val = 1;
                        if (p[0] == '\0' || LONE_DASH(p)) {
-                               if (!cmdline) {
+                               if (!login_sh) {
                                        /* "-" means turn off -x and -v */
                                        if (p[0] == '\0')
                                                xflag = vflag = 0;
@@ -11117,26 +11146,31 @@ options(int cmdline, int *login_sh)
                }
                /* first char was + or - */
                while ((c = *p++) != '\0') {
-                       /* bash 3.2 indeed handles -c CMD and +c CMD the same */
-                       if (c == 'c' && cmdline) {
-                               minusc = p;     /* command is after shell args */
-                       } else if (c == 'o') {
+                       if (login_sh) {
+                               /* bash 3.2 indeed handles -c CMD and +c CMD the same */
+                               if (c == 'c') {
+                                       minusc = p; /* command is after shell args */
+                                       continue;
+                               }
+                               if (c == 'l') {
+                                       *login_sh = 1; /* -l or +l == --login */
+                                       continue;
+                               }
+                               /* bash does not accept +-login, we also won't */
+                               if (val && (c == '-')) { /* long options */
+                                       if (strcmp(p, "login") == 0) {
+                                               *login_sh = 1;
+                                       }
+                                       break;
+                               }
+                       }
+                       if (c == 'o') {
                                if (plus_minus_o(*argptr, val)) {
                                        /* it already printed err message */
                                        return 1; /* error */
                                }
                                if (*argptr)
                                        argptr++;
-                       } else if (cmdline && (c == 'l')) { /* -l or +l == --login */
-                               if (login_sh)
-                                       *login_sh = 1;
-                       /* bash does not accept +-login, we also won't */
-                       } else if (cmdline && val && (c == '-')) { /* long options */
-                               if (strcmp(p, "login") == 0) {
-                                       if (login_sh)
-                                               *login_sh = 1;
-                               }
-                               break;
                        } else {
                                setoption(c, val);
                        }
@@ -11227,7 +11261,7 @@ setcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
                return showvars(nullstr, 0, VUNSET);
 
        INT_OFF;
-       retval = options(/*cmdline:*/ 0, NULL);
+       retval = options(/*login_sh:*/ NULL);
        if (retval == 0) { /* if no parse error... */
                optschanged();
                if (*argptr != NULL) {
@@ -13685,7 +13719,8 @@ helpcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 static int FAST_FUNC
 historycmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 {
-       show_history(line_input_state);
+       if (line_input_state)
+               show_history(line_input_state);
        return EXIT_SUCCESS;
 }
 #endif
@@ -14001,7 +14036,8 @@ exitshell(void)
        int status;
 
 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
-       save_history(line_input_state);
+       if (line_input_state)
+               save_history(line_input_state);
 #endif
        status = exitstatus;
        TRACE(("pid %d, exitshell(%d)\n", getpid(), status));
@@ -14123,7 +14159,7 @@ procargs(char **argv)
        argptr = xargv;
        for (i = 0; i < NOPTS; i++)
                optlist[i] = 2;
-       if (options(/*cmdline:*/ 1, &login_sh)) {
+       if (options(&login_sh)) {
                /* it already printed err message */
                raise_exception(EXERROR);
        }
@@ -14249,9 +14285,6 @@ int ash_main(int argc UNUSED_PARAM, char **argv)
        monitor(4, etext, profile_buf, sizeof(profile_buf), 50);
 #endif
 
-#if ENABLE_FEATURE_EDITING
-       line_input_state = new_line_input_t(FOR_SHELL | WITH_PATH_LOOKUP);
-#endif
        state = 0;
        if (setjmp(jmploc.loc)) {
                smallint e;