ash,hush: tab completion of functions and aliases

Rework the 'get_exe_name' functions in ash and hush so functions
and aliases are considered when tab-completing a command.

function                                             old     new   delta
ash_command_name                                       -     188    +188
hush_command_name                                      -     118    +118
complete_cmd_dir_file                                876     880      +4
ash_builtin_name                                      17       -     -17
hush_builtin_name                                     38       -     -38
------------------------------------------------------------------------------
(add/remove: 2/2 grow/shrink: 1/0 up/down: 310/-55)           Total: 255 bytes

(GitHub issue #301)

Signed-off-by: Ron Yorston <rmy@pobox.com>

4 files changed, 84 insertions, 15 deletions

diff --git a/include/libbb.h b/include/libbb.h
index 6191debb1..66781da4f 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1924,7 +1924,14 @@ unsigned size_from_HISTFILESIZE(const char *hp) FAST_FUNC;
 # else
 #  define MAX_HISTORY 0
 # endif
-typedef const char *get_exe_name_t(int i) FAST_FUNC;
+typedef struct exe_state {
+        int e_type;             /* type of tab completion:  builtin, alias, function */
+        int e_index;    /* index of current table entry or hash bucket */
+# if ENABLE_SHELL_ASH || (ENABLE_SHELL_HUSH && ENABLE_HUSH_FUNCTIONS)
+        void *e_ptr;    /* current position in linked list */
+# endif
+} exe_state;
+typedef const char *get_exe_name_t(exe_state *e) FAST_FUNC;
 typedef const char *sh_get_var_t(const char *name) FAST_FUNC;
 typedef struct line_input_t {
         int flags;
diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index 625884adf..5daceff16 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -875,9 +875,13 @@ static NOINLINE unsigned complete_cmd_dir_file(const char *command, int type)
 # endif
 # if ENABLE_SHELL_ASH || ENABLE_SHELL_HUSH
                 if (state->get_exe_name) {
-                        i = 0;
+#  if ENABLE_SHELL_ASH || (ENABLE_SHELL_HUSH && ENABLE_HUSH_FUNCTIONS)
+                        exe_state e = { 0, 0, NULL };
+#  else
+                        exe_state e = { 0, 0 };
+#  endif
                         for (;;) {
-                                const char *b = state->get_exe_name(i++);
+                                const char *b = state->get_exe_name(&e);
                                 if (!b)
                                         break;
                                 if (strncmp(basecmd, b, baselen) == 0)
diff --git a/shell/ash.c b/shell/ash.c
index 26239ff09..c77ee8620 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -9732,7 +9732,7 @@ evalpipe(union node *n, int flags)
 
 /* setinteractive needs this forward reference */
 #if ENABLE_FEATURE_TAB_COMPLETION
-static const char *ash_builtin_name(int i) FAST_FUNC;
+static const char *ash_command_name(exe_state *e) FAST_FUNC;
 #endif
 
 /*
@@ -9769,7 +9769,7 @@ setinteractive(int on)
                 if (!line_input_state) {
                         line_input_state = new_line_input_t(FOR_SHELL | WITH_PATH_LOOKUP);
 # if ENABLE_FEATURE_TAB_COMPLETION
-                        line_input_state->get_exe_name = ash_builtin_name;
+                        line_input_state->get_exe_name = ash_command_name;
 # endif
 # if EDITING_HAS_sh_get_var
                         line_input_state->sh_get_var = lookupvar;
@@ -10284,9 +10284,47 @@ find_builtin(const char *name)
 
 #if ENABLE_FEATURE_TAB_COMPLETION
 static const char * FAST_FUNC
-ash_builtin_name(int i)
-{
-        return /*i >= 0 &&*/ i < ARRAY_SIZE(builtintab) ? builtintab[i].name + 1 : NULL;
+ash_command_name(struct exe_state *e)
+{
+        if (e->e_type == 0) {
+                if (/*e->e_index >= 0 &&*/ e->e_index < ARRAY_SIZE(builtintab)) {
+                        return builtintab[e->e_index++].name + 1;
+                }
+                e->e_type++;
+                e->e_index = 0;
+                e->e_ptr = cmdtable[0];
+        }
+        if (e->e_type == 1) {
+                struct tblentry *cmdp = (struct tblentry *)e->e_ptr;
+                while (e->e_index < CMDTABLESIZE) {
+                        while (cmdp) {
+                                if (cmdp->cmdtype == CMDFUNCTION) {
+                                        e->e_ptr = cmdp->next;
+                                        return cmdp->cmdname;
+                                }
+                                cmdp = cmdp->next;
+                        }
+                        cmdp = cmdtable[++e->e_index];
+                }
+# if ENABLE_ASH_ALIAS
+                e->e_type++;
+                e->e_index = 0;
+                e->e_ptr = atab[0];
+# endif
+        }
+# if ENABLE_ASH_ALIAS
+        if (e->e_type == 2) {
+                struct alias *ap = (struct alias *)e->e_ptr;
+                while (e->e_index < ATABSIZE) {
+                        while (ap) {
+                                e->e_ptr = ap->next;
+                                return ap->name;
+                        }
+                        ap = atab[++e->e_index];
+                }
+        }
+# endif
+        return NULL;
 }
 #endif
 
diff --git a/shell/hush.c b/shell/hush.c
index 330a0aa79..443bdeccf 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -8220,15 +8220,35 @@ static const struct built_in_command *find_builtin(const char *name)
 }
 
 #if ENABLE_HUSH_JOB && ENABLE_FEATURE_TAB_COMPLETION
-static const char * FAST_FUNC hush_builtin_name(int i)
+static const char * FAST_FUNC hush_command_name(exe_state *e)
 {
-        if (/*i >= 0 && */ i < ARRAY_SIZE(bltins1)) {
-                return bltins1[i].b_cmd;
+        if (e->e_type == 0) {
+                if (/*e->e_index >= 0 && */ e->e_index < ARRAY_SIZE(bltins1)) {
+                        return bltins1[e->e_index++].b_cmd;
+                }
+                e->e_type++;
+                e->e_index = 0;
+                /* e->e_ptr = NULL; */
+        }
+        if (e->e_type == 1) {
+                if (e->e_index < ARRAY_SIZE(bltins2)) {
+                        return bltins2[e->e_index++].b_cmd;
+                }
+# if ENABLE_HUSH_FUNCTIONS
+                e->e_type++;
+                /* e->e_index = 0; */
+                e->e_ptr = G.top_func;
+# endif
         }
-        i -= ARRAY_SIZE(bltins1);
-        if (i < ARRAY_SIZE(bltins2)) {
-                return bltins2[i].b_cmd;
+# if ENABLE_HUSH_FUNCTIONS
+        if (e->e_type == 2) {
+                struct function *funcp = (struct function *)e->e_ptr;
+                while (funcp) {
+                        e->e_ptr = funcp->next;
+                        return funcp->name;
+                }
         }
+# endif
         return NULL;
 }
 #endif
@@ -10716,7 +10736,7 @@ int hush_main(int argc, char **argv)
 # if ENABLE_FEATURE_EDITING
                 G.line_input_state = new_line_input_t(FOR_SHELL);
 #  if ENABLE_FEATURE_TAB_COMPLETION
-                G.line_input_state->get_exe_name = hush_builtin_name;
+                G.line_input_state->get_exe_name = hush_command_name;
 #  endif
 #  if EDITING_HAS_sh_get_var
                 G.line_input_state->sh_get_var = get_local_var_value;