Remove `lv_len` and use `nlocals - 1` instead.

Check that `lv`'s length is always `nlocals - 1`.

include/mruby/irep.h

@@ -41,7 +41,7 @@ typedef struct mrb_irep {
   uint16_t *lines;
   struct mrb_irep_debug_info* debug_info;
 
-  size_t ilen, plen, slen, rlen, lv_len, refcnt;
+  size_t ilen, plen, slen, rlen, refcnt;
 } mrb_irep;
 
 #define MRB_ISEQ_NO_FREE 1

mrbgems/mruby-proc-ext/src/proc.c

@@ -137,8 +137,8 @@ mrb_local_variables(mrb_state *mrb, mrb_value self)
   }
 
   irep = proc->body.irep;
-  ret = mrb_ary_new_capa(mrb, irep->lv_len);
-  for (i = 0; i < irep->lv_len; ++i) {
+  ret = mrb_ary_new_capa(mrb, irep->nlocals - 1);
+  for (i = 0; i < (irep->nlocals - 1); ++i) {
     mrb_ary_push(mrb, ret, mrb_symbol_value(irep->lv[i].name));
   }
 

src/codegen.c

@@ -2496,20 +2496,16 @@ scope_new(mrb_state *mrb, codegen_scope *prev, node *lv)
   p->lv = lv;
   p->sp += node_len(lv)+1;        /* add self */
   p->nlocals = p->sp;
-  p->irep->lv_len = 0;
   if (lv) {
     node *n = lv;
     size_t i = 0;
 
-    for (n=lv; n; n=n->cdr) {
-      p->irep->lv_len++;
-    }
-
-    p->irep->lv = (struct mrb_locals*)mrb_malloc(mrb, sizeof(struct mrb_locals)*p->irep->lv_len);
+    p->irep->lv = (struct mrb_locals*)mrb_malloc(mrb, sizeof(struct mrb_locals) * (p->nlocals - 1));
     for (i=0, n=lv; n; i++,n=n->cdr) {
       p->irep->lv[i].name = lv_name(n);
       p->irep->lv[i].r = lv_idx(p, lv_name(n));
     }
+    mrb_assert(i == (p->nlocals - 1));
   }
   p->ai = mrb_gc_arena_save(mrb);
 

src/dump.c

@@ -693,7 +693,7 @@ write_section_debug(mrb_state *mrb, mrb_irep *irep, uint8_t *cur)
 }
 
 static void
-create_lv_sym_table(mrb_state *mrb, mrb_irep *irep, mrb_sym **syms, uint32_t *syms_len)
+create_lv_sym_table(mrb_state *mrb, const mrb_irep *irep, mrb_sym **syms, uint32_t *syms_len)
 {
   size_t i;
 
@@ -701,7 +701,7 @@ create_lv_sym_table(mrb_state *mrb, mrb_irep *irep, mrb_sym **syms, uint32_t *sy
     *syms = (mrb_sym*)mrb_malloc(mrb, sizeof(mrb_sym) * 1);
   }
 
-  for (i = 0; i < irep->lv_len; ++i) {
+  for (i = 0; i < (irep->nlocals - 1); ++i) {
     mrb_sym const name = irep->lv[i].name;
     if (find_filename_index(*syms, *syms_len, name) != -1) continue;
 
@@ -738,13 +738,12 @@ write_lv_sym_table(mrb_state *mrb, uint8_t **start, mrb_sym const *syms, uint32_
 }
 
 static int
-write_lv_record(mrb_state *mrb, mrb_irep *irep, uint8_t **start, mrb_sym const *syms, uint32_t syms_len)
+write_lv_record(mrb_state *mrb, const mrb_irep *irep, uint8_t **start, mrb_sym const *syms, uint32_t syms_len)
 {
   uint8_t *cur = *start;
   size_t i;
 
-  cur += uint16_to_bin(irep->lv_len, cur);
-  for (i = 0; i < irep->lv_len; ++i) {
+  for (i = 0; i < (irep->nlocals - 1); ++i) {
     int const sym_idx = find_filename_index(syms, syms_len, irep->lv[i].name);
     mrb_assert(sym_idx != -1); /* local variable name must be in syms */
 
@@ -766,8 +765,7 @@ get_lv_record_size(mrb_state *mrb, mrb_irep *irep)
 {
   size_t ret = 0, i;
 
-  ret += sizeof(uint16_t); /* lv_len */
-  ret += (sizeof(uint16_t) + sizeof(uint32_t)) * irep->lv_len;
+  ret += (sizeof(uint16_t) + sizeof(uint32_t)) * (irep->nlocals - 1);
 
   for (i = 0; i < irep->rlen; ++i) {
     ret += get_lv_record_size(mrb, irep->reps[i]);

src/load.c

@@ -408,11 +408,9 @@ read_lv_record(mrb_state *mrb, const uint8_t *start, mrb_irep *irep, size_t *rec
   size_t i;
   ptrdiff_t diff;
 
-  irep->lv_len = bin_to_uint16(bin);
-  bin += sizeof(uint16_t);
-  irep->lv = (struct mrb_locals*)mrb_malloc(mrb, sizeof(struct mrb_locals) * irep->lv_len);
+  irep->lv = (struct mrb_locals*)mrb_malloc(mrb, sizeof(struct mrb_locals) * (irep->nlocals - 1));
 
-  for (i = 0; i < irep->lv_len; ++i) {
+  for (i = 0; i < (irep->nlocals - 1); ++i) {
     uint16_t const sym_idx = bin_to_uint16(bin);
     bin += sizeof(uint16_t);
     if (sym_idx >= syms_len) {