hush: a few relatively trivial simplifications

function                                             old     new   delta
helper_export_local                                  130     135      +5
set_vars_and_save_old                                 89      85      -4
expand_variables                                     147     141      -6
get_ptr_to_local_var                                  77      70      -7
get_local_var_value                                  171     164      -7
delete_finished_bg_job                                31      16     -15
hush_exit                                            101      84     -17
free_pipe_list                                        31      12     -19
check_and_run_traps                                  232     205     -27
free_pipe                                            205     130     -75
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/9 up/down: 5/-177)           Total: -172 bytes

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

1 files changed, 53 insertions, 58 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 54aee882e..ae2876ac7 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -1344,11 +1344,14 @@ static void hush_exit(int exitcode)
                 /* Prevent recursion:
                  * trap "echo Hi; exit" EXIT; exit
                  */
-                char *argv[] = { NULL, G.traps[0], NULL };
+                char *argv[3];
+                /* argv[0] is unused */
+                argv[1] = G.traps[0];
+                argv[2] = NULL;
                 G.traps[0] = NULL;
                 G.exiting = 1;
                 builtin_eval(argv);
-                free(argv[1]);
+                /* free(argv[1]); - why bother */
         }
 
 #if ENABLE_HUSH_JOB
@@ -1376,10 +1379,12 @@ static int check_and_run_traps(int sig)
                 if (G.traps && G.traps[sig]) {
                         if (G.traps[sig][0]) {
                                 /* We have user-defined handler */
-                                char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
+                                char *argv[3];
+                                /* argv[0] is unused */
+                                argv[1] = G.traps[sig];
+                                argv[2] = NULL;
                                 save_rcode = G.last_exitcode;
                                 builtin_eval(argv);
-                                free(argv[1]);
                                 G.last_exitcode = save_rcode;
                         } /* else: "" trap, ignoring signal */
                         continue;
@@ -1439,13 +1444,11 @@ static const char *get_cwd(int force)
 /*
  * Shell and environment variable support
  */
-static struct variable **get_ptr_to_local_var(const char *name)
+static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
 {
         struct variable **pp;
         struct variable *cur;
-        int len;
 
-        len = strlen(name);
         pp = &G.top_var;
         while ((cur = *pp) != NULL) {
                 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
@@ -1455,21 +1458,13 @@ static struct variable **get_ptr_to_local_var(const char *name)
         return NULL;
 }
 
-static struct variable *get_local_var(const char *name)
-{
-        struct variable **pp = get_ptr_to_local_var(name);
-        if (pp)
-                return *pp;
-        return NULL;
-}
-
 static const char* FAST_FUNC get_local_var_value(const char *name)
 {
         struct variable **vpp;
+        unsigned len = strlen(name);
 
         if (G.expanded_assignments) {
                 char **cpp = G.expanded_assignments;
-                int len = strlen(name);
                 while (*cpp) {
                         char *cp = *cpp;
                         if (strncmp(cp, name, len) == 0 && cp[len] == '=')
@@ -1478,17 +1473,16 @@ static const char* FAST_FUNC get_local_var_value(const char *name)
                 }
         }
 
-        vpp = get_ptr_to_local_var(name);
+        vpp = get_ptr_to_local_var(name, len);
         if (vpp)
-                return strchr((*vpp)->varstr, '=') + 1;
+                return (*vpp)->varstr + len + 1;
 
         if (strcmp(name, "PPID") == 0)
                 return utoa(G.root_ppid);
         // bash compat: UID? EUID?
 #if ENABLE_HUSH_RANDOM_SUPPORT
-        if (strcmp(name, "RANDOM") == 0) {
+        if (strcmp(name, "RANDOM") == 0)
                 return utoa(next_random(&G.random_gen));
-        }
 #endif
         return NULL;
 }
@@ -1738,9 +1732,7 @@ static struct variable *set_vars_and_save_old(char **strings)
 
                 eq = strchr(*s, '=');
                 if (eq) {
-                        *eq = '\0';
-                        var_pp = get_ptr_to_local_var(*s);
-                        *eq = '=';
+                        var_pp = get_ptr_to_local_var(*s, eq - *s);
                         if (var_pp) {
                                 /* Remove variable from global linked list */
                                 var_p = *var_pp;
@@ -2500,33 +2492,36 @@ static char **o_finalize_list(o_string *o, int n)
         list[--n] = NULL;
         while (n) {
                 n--;
-                list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
+                list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
         }
         return list;
 }
 
-static void free_pipe_list(struct pipe *head);
+static void free_pipe_list(struct pipe *pi);
 
-/* Return code is the exit status of the pipe */
-static void free_pipe(struct pipe *pi)
+/* Returns pi->next - next pipe in the list */
+static struct pipe *free_pipe(struct pipe *pi)
 {
-        char **p;
-        struct command *command;
-        struct redir_struct *r, *rnext;
-        int a, i;
+        struct pipe *next;
+        int i;
 
-        if (pi->stopped_cmds > 0) /* why? */
-                return;
-        debug_printf_clean("run pipe: (pid %d)\n", getpid());
+        debug_printf_clean("free_pipe (pid %d)\n", getpid());
         for (i = 0; i < pi->num_cmds; i++) {
+                struct command *command;
+                struct redir_struct *r, *rnext;
+
                 command = &pi->cmds[i];
                 debug_printf_clean("  command %d:\n", i);
                 if (command->argv) {
-                        for (a = 0, p = command->argv; *p; a++, p++) {
-                                debug_printf_clean("   argv[%d] = %s\n", a, *p);
+                        if (DEBUG_CLEAN) {
+                                int a;
+                                char **p;
+                                for (a = 0, p = command->argv; *p; a++, p++) {
+                                        debug_printf_clean("   argv[%d] = %s\n", a, *p);
+                                }
                         }
                         free_strings(command->argv);
-                        command->argv = NULL;
+                        //command->argv = NULL;
                 }
                 /* not "else if": on syntax error, we may have both! */
                 if (command->group) {
@@ -2534,7 +2529,7 @@ static void free_pipe(struct pipe *pi)
                                         command->cmd_type);
                         free_pipe_list(command->group);
                         debug_printf_clean("   end group\n");
-                        command->group = NULL;
+                        //command->group = NULL;
                 }
                 /* else is crucial here.
                  * If group != NULL, child_func is meaningless */
@@ -2546,7 +2541,7 @@ static void free_pipe(struct pipe *pi)
 #endif
 #if !BB_MMU
                 free(command->group_as_string);
-                command->group_as_string = NULL;
+                //command->group_as_string = NULL;
 #endif
                 for (r = command->redirects; r; r = rnext) {
                         debug_printf_clean("   redirect %d%s",
@@ -2555,35 +2550,34 @@ static void free_pipe(struct pipe *pi)
                         if (r->rd_filename) {
                                 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
                                 free(r->rd_filename);
-                                r->rd_filename = NULL;
+                                //r->rd_filename = NULL;
                         }
                         debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
                         rnext = r->next;
                         free(r);
                 }
-                command->redirects = NULL;
+                //command->redirects = NULL;
         }
         free(pi->cmds);   /* children are an array, they get freed all at once */
-        pi->cmds = NULL;
+        //pi->cmds = NULL;
 #if ENABLE_HUSH_JOB
         free(pi->cmdtext);
-        pi->cmdtext = NULL;
+        //pi->cmdtext = NULL;
 #endif
+
+        next = pi->next;
+        free(pi);
+        return next;
 }
 
-static void free_pipe_list(struct pipe *head)
+static void free_pipe_list(struct pipe *pi)
 {
-        struct pipe *pi, *next;
-
-        for (pi = head; pi; pi = next) {
+        while (pi) {
 #if HAS_KEYWORDS
-                debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
+                debug_printf_clean("pipe reserved word %d\n", pi->res_word);
 #endif
-                free_pipe(pi);
                 debug_printf_clean("pipe followup code %d\n", pi->followup);
-                next = pi->next;
-                /*pi->next = NULL;*/
-                free(pi);
+                pi = free_pipe(pi);
         }
 }
 
@@ -6184,15 +6178,13 @@ static void remove_bg_job(struct pipe *pi)
 static void delete_finished_bg_job(struct pipe *pi)
 {
         remove_bg_job(pi);
-        pi->stopped_cmds = 0;
         free_pipe(pi);
-        free(pi);
 }
 #endif /* JOB */
 
 /* Check to see if any processes have exited -- if they
  * have, figure out why and see if a job has completed */
-static int checkjobs(struct pipe* fg_pipe)
+static int checkjobs(struct pipe *fg_pipe)
 {
         int attributes;
         int status;
@@ -7879,13 +7871,16 @@ static void helper_export_local(char **argv, int exp, int lvl)
 {
         do {
                 char *name = *argv;
+                char *name_end = strchrnul(name, '=');
 
                 /* So far we do not check that name is valid (TODO?) */
 
-                if (strchr(name, '=') == NULL) {
-                        struct variable *var;
+                if (*name_end == '\0') {
+                        struct variable *var, **vpp;
+
+                        vpp = get_ptr_to_local_var(name, name_end - name);
+                        var = vpp ? *vpp : NULL;
 
-                        var = get_local_var(name);
                         if (exp == -1) { /* unexporting? */
                                 /* export -n NAME (without =VALUE) */
                                 if (var) {