ash: remove one redundant function, improve string sharing, better field names

function                                             old     new   delta
var_end                                                -      15     +15
changepath                                           194     192      -2
setvareq                                             222     218      -4
lookupvar                                             57      51      -6
bltinlookup                                           57      51      -6
evalfun                                              452     443      -9
varequal                                              14       -     -14
------------------------------------------------------------------------------
(add/remove: 1/1 grow/shrink: 0/5 up/down: 15/-41)            Total: -26 bytes

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

1 files changed, 57 insertions, 55 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 9e7da1edd..d77d9d3c2 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -279,6 +279,14 @@ static int isdigit_str9(const char *str)
         return (*str == '\0');
 }
 
+static const char *var_end(const char *var)
+{
+        while (*var)
+                if (*var++ == '=')
+                        break;
+        return var;
+}
+
 
 /* ============ Interrupts / exceptions */
 /*
@@ -1712,8 +1720,8 @@ static void FAST_FUNC getoptsreset(const char *value);
 struct var {
         struct var *next;               /* next entry in hash list */
         int flags;                      /* flags are defined above */
-        const char *text;               /* name=value */
-        void (*func)(const char *) FAST_FUNC; /* function to be called when  */
+        const char *var_text;           /* name=value */
+        void (*var_func)(const char *) FAST_FUNC; /* function to be called when  */
                                         /* the variable gets set/unset */
 };
 
@@ -1767,13 +1775,13 @@ static void change_random(const char *) FAST_FUNC;
 
 static const struct {
         int flags;
-        const char *text;
-        void (*func)(const char *) FAST_FUNC;
+        const char *var_text;
+        void (*var_func)(const char *) FAST_FUNC;
 } varinit_data[] = {
         { VSTRFIXED|VTEXTFIXED       , defifsvar   , NULL            },
 #if ENABLE_ASH_MAIL
-        { VSTRFIXED|VTEXTFIXED|VUNSET, "MAIL\0"    , changemail      },
-        { VSTRFIXED|VTEXTFIXED|VUNSET, "MAILPATH\0", changemail      },
+        { VSTRFIXED|VTEXTFIXED|VUNSET, "MAIL"      , changemail      },
+        { VSTRFIXED|VTEXTFIXED|VUNSET, "MAILPATH"  , changemail      },
 #endif
         { VSTRFIXED|VTEXTFIXED       , bb_PATH_root_path, changepath },
         { VSTRFIXED|VTEXTFIXED       , "PS1=$ "    , NULL            },
@@ -1783,14 +1791,14 @@ static const struct {
         { VSTRFIXED|VTEXTFIXED       , "OPTIND=1"  , getoptsreset    },
 #endif
 #if ENABLE_ASH_RANDOM_SUPPORT
-        { VSTRFIXED|VTEXTFIXED|VUNSET|VDYNAMIC, "RANDOM\0", change_random },
+        { VSTRFIXED|VTEXTFIXED|VUNSET|VDYNAMIC, "RANDOM", change_random },
 #endif
 #if ENABLE_LOCALE_SUPPORT
-        { VSTRFIXED|VTEXTFIXED|VUNSET, "LC_ALL\0"  , change_lc_all   },
-        { VSTRFIXED|VTEXTFIXED|VUNSET, "LC_CTYPE\0", change_lc_ctype },
+        { VSTRFIXED|VTEXTFIXED|VUNSET, "LC_ALL"    , change_lc_all   },
+        { VSTRFIXED|VTEXTFIXED|VUNSET, "LC_CTYPE"  , change_lc_ctype },
 #endif
 #if ENABLE_FEATURE_EDITING_SAVEHISTORY
-        { VSTRFIXED|VTEXTFIXED|VUNSET, "HISTFILE\0", NULL            },
+        { VSTRFIXED|VTEXTFIXED|VUNSET, "HISTFILE"  , NULL            },
 #endif
 };
 
@@ -1817,9 +1825,9 @@ extern struct globals_var *const ash_ptr_to_globals_var;
         (*(struct globals_var**)&ash_ptr_to_globals_var) = xzalloc(sizeof(G_var)); \
         barrier(); \
         for (i = 0; i < ARRAY_SIZE(varinit_data); i++) { \
-                varinit[i].flags = varinit_data[i].flags; \
-                varinit[i].text  = varinit_data[i].text; \
-                varinit[i].func  = varinit_data[i].func; \
+                varinit[i].flags    = varinit_data[i].flags; \
+                varinit[i].var_text = varinit_data[i].var_text; \
+                varinit[i].var_func = varinit_data[i].var_func; \
         } \
 } while (0)
 
@@ -1850,19 +1858,19 @@ extern struct globals_var *const ash_ptr_to_globals_var;
  * They have to skip over the name.  They return the null string
  * for unset variables.
  */
-#define ifsval()        (vifs.text + 4)
+#define ifsval()        (vifs.var_text + 4)
 #define ifsset()        ((vifs.flags & VUNSET) == 0)
 #if ENABLE_ASH_MAIL
-# define mailval()      (vmail.text + 5)
-# define mpathval()     (vmpath.text + 9)
+# define mailval()      (vmail.var_text + 5)
+# define mpathval()     (vmpath.var_text + 9)
 # define mpathset()     ((vmpath.flags & VUNSET) == 0)
 #endif
-#define pathval()       (vpath.text + 5)
-#define ps1val()        (vps1.text + 4)
-#define ps2val()        (vps2.text + 4)
-#define ps4val()        (vps4.text + 4)
+#define pathval()       (vpath.var_text + 5)
+#define ps1val()        (vps1.var_text + 4)
+#define ps2val()        (vps2.var_text + 4)
+#define ps4val()        (vps4.var_text + 4)
 #if ENABLE_ASH_GETOPTS
-# define optindval()    (voptind.text + 7)
+# define optindval()    (voptind.var_text + 7)
 #endif
 
 
@@ -1921,12 +1929,6 @@ varcmp(const char *p, const char *q)
         return c - d;
 }
 
-static int
-varequal(const char *a, const char *b)
-{
-        return !varcmp(a, b);
-}
-
 /*
  * Find the appropriate entry in the hash table from the name.
  */
@@ -1961,15 +1963,15 @@ initvar(void)
          * PS1 depends on uid
          */
 #if ENABLE_FEATURE_EDITING && ENABLE_FEATURE_EDITING_FANCY_PROMPT
-        vps1.text = "PS1=\\w \\$ ";
+        vps1.var_text = "PS1=\\w \\$ ";
 #else
         if (!geteuid())
-                vps1.text = "PS1=# ";
+                vps1.var_text = "PS1=# ";
 #endif
         vp = varinit;
         end = vp + ARRAY_SIZE(varinit);
         do {
-                vpp = hashvar(vp->text);
+                vpp = hashvar(vp->var_text);
                 vp->next = *vpp;
                 *vpp = vp;
         } while (++vp < end);
@@ -1979,7 +1981,7 @@ static struct var **
 findvar(struct var **vpp, const char *name)
 {
         for (; *vpp; vpp = &(*vpp)->next) {
-                if (varequal((*vpp)->text, name)) {
+                if (varcmp((*vpp)->var_text, name) == 0) {
                         break;
                 }
         }
@@ -2003,11 +2005,11 @@ lookupvar(const char *name)
          * As soon as they're unset, they're no longer dynamic, and dynamic
          * lookup will no longer happen at that point. -- PFM.
          */
-                if ((v->flags & VDYNAMIC))
-                        (*v->func)(NULL);
+                if (v->flags & VDYNAMIC)
+                        v->var_func(NULL);
 #endif
                 if (!(v->flags & VUNSET))
-                        return strchrnul(v->text, '=') + 1;
+                        return var_end(v->var_text);
         }
         return NULL;
 }
@@ -2021,8 +2023,8 @@ bltinlookup(const char *name)
         struct strlist *sp;
 
         for (sp = cmdenviron; sp; sp = sp->next) {
-                if (varequal(sp->text, name))
-                        return strchrnul(sp->text, '=') + 1;
+                if (varcmp(sp->text, name) == 0)
+                        return var_end(sp->text);
         }
         return lookupvar(name);
 }
@@ -2048,24 +2050,24 @@ setvareq(char *s, int flags)
 
                         if (flags & VNOSAVE)
                                 free(s);
-                        n = vp->text;
+                        n = vp->var_text;
                         ash_msg_and_raise_error("%.*s: is read only", strchrnul(n, '=') - n, n);
                 }
 
                 if (flags & VNOSET)
                         return;
 
-                if (vp->func && (flags & VNOFUNC) == 0)
-                        (*vp->func)(strchrnul(s, '=') + 1);
+                if (vp->var_func && !(flags & VNOFUNC))
+                        vp->var_func(var_end(s));
 
-                if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
-                        free((char*)vp->text);
+                if (!(vp->flags & (VTEXTFIXED|VSTACK)))
+                        free((char*)vp->var_text);
 
                 flags |= vp->flags & ~(VTEXTFIXED|VSTACK|VNOSAVE|VUNSET);
         } else {
+                /* variable s is not found */
                 if (flags & VNOSET)
                         return;
-                /* not found */
                 vp = ckzalloc(sizeof(*vp));
                 vp->next = *vpp;
                 /*vp->func = NULL; - ckzalloc did it */
@@ -2073,7 +2075,7 @@ setvareq(char *s, int flags)
         }
         if (!(flags & (VTEXTFIXED|VSTACK|VNOSAVE)))
                 s = ckstrdup(s);
-        vp->text = s;
+        vp->var_text = s;
         vp->flags = flags;
 }
 
@@ -2171,7 +2173,7 @@ unsetvar(const char *s)
                 if ((flags & VSTRFIXED) == 0) {
                         INT_OFF;
                         if ((flags & (VTEXTFIXED|VSTACK)) == 0)
-                                free((char*)vp->text);
+                                free((char*)vp->var_text);
                         *vpp = vp->next;
                         free(vp);
                         INT_ON;
@@ -2223,7 +2225,7 @@ listvars(int on, int off, char ***end)
                         if ((vp->flags & mask) == on) {
                                 if (ep == stackstrend())
                                         ep = growstackstr();
-                                *ep++ = (char *) vp->text;
+                                *ep++ = (char*)vp->var_text;
                         }
                 }
         } while (++vpp < vartab + VTABSIZE);
@@ -6591,7 +6593,7 @@ evalvar(char *p, int flags, struct strlist *var_str_list)
         var = p;
         easy = (!quoted || (*var == '@' && shellparam.nparam));
         startloc = expdest - (char *)stackblock();
-        p = strchr(p, '=') + 1;
+        p = strchr(p, '=') + 1; //TODO: use var_end(p)?
 
  again:
         varlen = varvalue(var, varflags, flags, var_str_list);
@@ -8637,14 +8639,14 @@ poplocalvars(void)
                         free((char*)lvp->text);
                         optschanged();
                 } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) {
-                        unsetvar(vp->text);
+                        unsetvar(vp->var_text);
                 } else {
-                        if (vp->func)
-                                (*vp->func)(strchrnul(lvp->text, '=') + 1);
+                        if (vp->var_func)
+                                vp->var_func(var_end(lvp->text));
                         if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
-                                free((char*)vp->text);
+                                free((char*)vp->var_text);
                         vp->flags = lvp->flags;
-                        vp->text = lvp->text;
+                        vp->var_text = lvp->text;
                 }
                 free(lvp);
         }
@@ -8763,7 +8765,7 @@ mklocal(char *name)
                         vp = *vpp;      /* the new variable */
                         lvp->flags = VUNSET;
                 } else {
-                        lvp->text = vp->text;
+                        lvp->text = vp->var_text;
                         lvp->flags = vp->flags;
                         vp->flags |= VSTRFIXED|VTEXTFIXED;
                         if (eq)
@@ -9073,7 +9075,7 @@ evalcommand(union node *cmd, int flags)
         expredir(cmd->ncmd.redirect);
         status = redirectsafe(cmd->ncmd.redirect, REDIR_PUSH | REDIR_SAVEFD2);
 
-        path = vpath.text;
+        path = vpath.var_text;
         for (argp = cmd->ncmd.assign; argp; argp = argp->narg.next) {
                 struct strlist **spp;
                 char *p;
@@ -9086,7 +9088,7 @@ evalcommand(union node *cmd, int flags)
                  * is present
                  */
                 p = (*spp)->text;
-                if (varequal(p, path))
+                if (varcmp(p, path) == 0)
                         path = p;
         }
 
@@ -10113,7 +10115,7 @@ change_random(const char *value)
                 /* "get", generate */
                 t = next_random(&random_gen);
                 /* set without recursion */
-                setvar(vrandom.text, utoa(t), VNOFUNC);
+                setvar(vrandom.var_text, utoa(t), VNOFUNC);
                 vrandom.flags &= ~VNOFUNC;
         } else {
                 /* set/reset */