bc: make bc_program_addFunc() return new idx, untangle &p->fidx interaction

In:
       bc_program_addFunc(name, idx);
       p->func = bc_program_func(p->fidx);
in some cases p->fidx was updated by _first_ statement - because passed idx
was pointing at it. This was very obscure.

function                                             old     new   delta
zdc_parse_expr                                       653     658      +5
bc_program_addFunc                                   204     201      -3
zbc_vm_process                                       594     586      -8
bc_vm_init                                           663     655      -8
zbc_parse_name                                       482     472     -10
bc_parse_addFunc                                      25       -     -25
zbc_program_asciify                                  473     447     -26
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 1/5 up/down: 5/-80)             Total: -75 bytes
   text	   data	    bss	    dec	    hex	filename
 981482	    485	   7296	 989263	  f184f	busybox_old
 981401	    485	   7296	 989182	  f17fe	busybox_unstripped

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

1 files changed, 43 insertions, 47 deletions

diff --git a/miscutils/bc.c b/miscutils/bc.c
index ec7a0838b..d03d38aa9 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -3439,15 +3439,6 @@ static BC_STATUS zdc_lex_token(BcLex *l)
 }
 #endif // ENABLE_DC
 
-static void bc_program_addFunc(char *name, size_t *idx);
-
-// Note: takes ownership of 'name' (must be malloced)
-static void bc_parse_addFunc(BcParse *p, char *name, size_t *idx)
-{
-        bc_program_addFunc(name, idx);
-        p->func = bc_program_func(p->fidx);
-}
-
 static void bc_parse_push(BcParse *p, char i)
 {
         dbg_compile("%s:%d pushing bytecode %zd:%d", __func__, __LINE__, p->func->code.len, i);
@@ -3721,6 +3712,39 @@ static BC_STATUS zbc_parse_params(BcParse *p, uint8_t flags)
 #define zbc_parse_params(...) (zbc_parse_params(__VA_ARGS__) COMMA_SUCCESS)
 
 // Note: takes ownership of 'name' (must be malloced)
+static size_t bc_program_addFunc(char *name)
+{
+        size_t idx;
+        BcId entry, *entry_ptr;
+        BcFunc f;
+        int inserted;
+
+        entry.name = name;
+        entry.idx = G.prog.fns.len;
+
+        inserted = bc_map_insert(&G.prog.fn_map, &entry, &idx);
+        if (!inserted) free(name);
+
+        entry_ptr = bc_vec_item(&G.prog.fn_map, idx);
+        idx = entry_ptr->idx;
+
+        if (!inserted) {
+                BcFunc *func = bc_program_func(entry_ptr->idx);
+
+                // We need to reset these, so the function can be repopulated.
+                func->nparams = 0;
+                bc_vec_pop_all(&func->autos);
+                bc_vec_pop_all(&func->code);
+                bc_vec_pop_all(&func->labels);
+        } else {
+                bc_func_init(&f);
+                bc_vec_push(&G.prog.fns, &f);
+        }
+
+        return idx;
+}
+
+// Note: takes ownership of 'name' (must be malloced)
 static BC_STATUS zbc_parse_call(BcParse *p, char *name, uint8_t flags)
 {
         BcStatus s;
@@ -3741,7 +3765,7 @@ static BC_STATUS zbc_parse_call(BcParse *p, char *name, uint8_t flags)
 
         if (idx == BC_VEC_INVALID_IDX) {
                 // No such function exists, create an empty one
-                bc_parse_addFunc(p, name, &idx);
+                bc_program_addFunc(name);
                 idx = bc_map_find_exact(&G.prog.fn_map, &entry);
         } else
                 free(name);
@@ -4249,7 +4273,8 @@ static BC_STATUS zbc_parse_funcdef(BcParse *p)
                 RETURN_STATUS(bc_error("bad function definition"));
 
         name = xstrdup(p->l.t.v.v);
-        bc_parse_addFunc(p, name, &p->fidx);
+        p->fidx = bc_program_addFunc(name);
+        p->func = bc_program_func(p->fidx);
 
         s = zbc_lex_next(&p->l);
         if (s) RETURN_STATUS(s);
@@ -4741,7 +4766,7 @@ static BC_STATUS zdc_parse_register(BcParse *p)
 static BC_STATUS zdc_parse_string(BcParse *p)
 {
         char *str, *name;
-        size_t idx, len = G.prog.strs.len;
+        size_t len = G.prog.strs.len;
 
 //why pad to 32 zeros??
         name = xasprintf("%032lu", (unsigned long)len);
@@ -4750,7 +4775,8 @@ static BC_STATUS zdc_parse_string(BcParse *p)
         bc_parse_push(p, BC_INST_STR);
         bc_parse_pushIndex(p, len);
         bc_vec_push(&G.prog.strs, &str);
-        bc_parse_addFunc(p, name, &idx);
+        bc_program_addFunc(name);
+        p->func = bc_program_func(p->fidx);
 
         RETURN_STATUS(zbc_lex_next(&p->l));
 }
@@ -6121,7 +6147,7 @@ static BC_STATUS zbc_program_asciify(void)
         //str[1] = '\0'; - already is
 
         str2 = xstrdup(str);
-        bc_program_addFunc(str2, &idx);
+        idx = bc_program_addFunc(str2);
 
         if (idx != len + BC_PROG_REQ_FUNCS) {
                 for (idx = 0; idx < G.prog.strs.len; ++idx) {
@@ -6318,36 +6344,6 @@ static void bc_program_pushGlobal(char inst)
         bc_vec_push(&G.prog.results, &res);
 }
 
-// Note: takes ownership of 'name' (must be malloced)
-static void bc_program_addFunc(char *name, size_t *idx)
-{
-        BcId entry, *entry_ptr;
-        BcFunc f;
-        int inserted;
-
-        entry.name = name;
-        entry.idx = G.prog.fns.len;
-
-        inserted = bc_map_insert(&G.prog.fn_map, &entry, idx);
-        if (!inserted) free(name);
-
-        entry_ptr = bc_vec_item(&G.prog.fn_map, *idx);
-        *idx = entry_ptr->idx;
-
-        if (!inserted) {
-                BcFunc *func = bc_program_func(entry_ptr->idx);
-
-                // We need to reset these, so the function can be repopulated.
-                func->nparams = 0;
-                bc_vec_pop_all(&func->autos);
-                bc_vec_pop_all(&func->code);
-                bc_vec_pop_all(&func->labels);
-        } else {
-                bc_func_init(&f);
-                bc_vec_push(&G.prog.fns, &f);
-        }
-}
-
 static BC_STATUS zbc_program_exec(void)
 {
         BcResult r, *ptr;
@@ -6982,7 +6978,6 @@ static void bc_vm_free(void)
 
 static void bc_program_init(void)
 {
-        size_t idx;
         BcInstPtr ip;
 
         // memset(&G.prog, 0, sizeof(G.prog)); - already is
@@ -7004,8 +6999,9 @@ static void bc_program_init(void)
         bc_vec_init(&G.prog.fns, sizeof(BcFunc), bc_func_free);
         bc_vec_init(&G.prog.fn_map, sizeof(BcId), bc_id_free);
 
-        bc_program_addFunc(xstrdup("(main)"), &idx);
-        bc_program_addFunc(xstrdup("(read)"), &idx);
+//TODO: with "", dc_strings.dc enters infinite loop, ??!
+        bc_program_addFunc(xstrdup("(m)")); // func #0: main
+        bc_program_addFunc(xstrdup("(r)")); // func #1: for read()
 
         bc_vec_init(&G.prog.vars, sizeof(BcVec), bc_vec_free);
         bc_vec_init(&G.prog.var_map, sizeof(BcId), bc_id_free);