wip: working on extern in VM

- Feat: add usage of vm reader instead of old way in vm.c
- Ref: update debug opcodes printing

src/vm/fzl_vm.c

@@ -12,6 +12,7 @@
 #include <vm/fzl_vm.h>
 #include <vm/fzl_vm_env.h>
 #include <vm/fzl_vm_object.h>
+#include <vm/fzl_vm_reader.h>
 #include <vm/internals/opcode.h>
 
 char last_err[256];
@@ -20,8 +21,14 @@ size_t total_jmp_on_same = 0;
 
 static char *expect_hdr = "FZL\0\2";
 
-fzl_vm_t *fzl_mkvm(const char *filepath)
+fzl_vm_t *fzl_mkvm(fzl_vm_reader_t *reader)
 {
+  if (!reader)
+  {
+    snprintf(last_err, sizeof(last_err), "reader is not provided");
+    return NULL;
+  }
+
   fzl_vm_t *vm = malloc(sizeof(fzl_vm_t));
   if (!vm)
   {
@@ -30,86 +37,7 @@ fzl_vm_t *fzl_mkvm(const char *filepath)
   }
 
   memset(vm, 0, sizeof(fzl_vm_t));
-
-  FILE *fd = fopen(filepath, "rb");
-  if (!fd)
-  {
-    snprintf(last_err, sizeof(last_err), "failed to open file '%s'", filepath);
-    free(vm);
-    return NULL;
-  }
-
-  char hdr[5];
-  fread(hdr, sizeof(char), 5,
-        fd); // NOTE: add red bytes check (also for freads below)
-  if (memcmp(hdr, expect_hdr, 5) != 0)
-  {
-    snprintf(last_err, sizeof(last_err), "magic check error");
-    fclose(fd);
-    free(vm);
-    return NULL;
-  }
-
-  size_t consts_count, ops_count;
-  fread(&consts_count, sizeof(size_t), 1, fd);
-  fread(&ops_count, sizeof(size_t), 1, fd);
-  // TODO: read externs count
-
-  if (ops_count < 1)
-  {
-    snprintf(last_err, sizeof(last_err), "there is nothing to do (0 ops)");
-    fclose(fd);
-    free(vm);
-    return NULL;
-  }
-
-  if (consts_count > 0)
-  {
-    vm->consts_count = consts_count;
-    vm->consts       = malloc(consts_count * sizeof(fzl_value_t));
-
-    for (size_t i = 0; i < consts_count; i++)
-    {
-      fzl_consttype_t type;
-      fread(&type, sizeof(fzl_consttype_t), 1, fd);
-
-      if (type == FZL_CONSTTYPE_STRING)
-      {
-        size_t length;
-        char *chars;
-
-        fread(&length, sizeof(size_t), 1, fd);
-
-        chars = malloc(length * sizeof(char) + 1);
-        fread(chars, sizeof(char), length, fd);
-        chars[length] = 0;
-
-        vm->consts[i] = (fzl_const_t){
-            .type = type, .as.string.length = length, .as.string.chars = chars};
-      }
-      else
-      {
-        fclose(fd);
-        free(vm->consts);
-        free(vm);
-        snprintf(last_err, sizeof(last_err), "unknown const type at index %ld",
-                 i);
-        return NULL;
-      }
-    }
-  }
-
-  vm->ops_count = ops_count;
-  vm->ops       = malloc(ops_count * sizeof(uint64_t));
-  for (size_t i = 0; i < ops_count; i++)
-  {
-    uint64_t op;
-    fread(&op, sizeof(uint64_t), 1, fd);
-    vm->ops[i] = op;
-  }
-
-  // TODO: read externs
-  fclose(fd);
+  vm->reader = reader;
 
   return vm;
 }
@@ -229,9 +157,9 @@ int fzl_vm_run(fzl_vm_t *vm)
 
   vm->ip     = 0;
   int result = 0;
-  while (vm->ip < vm->ops_count)
+  while (vm->ip < vm->reader->ops_count)
   {
-    fzl_opcode_t opcode = vm->ops[vm->ip];
+    fzl_opcode_t opcode = vm->reader->ops[vm->ip];
     size_t op_group     = (opcode >> 16) & 0xFF;
     size_t op_fnnum     = (opcode & 0xFF);
 
@@ -265,13 +193,5 @@ void fzl_freevm(fzl_vm_t *vm)
   while (vm->etop > 0)
     fzl_freeenv(vm->estack[--vm->etop]);
 
-  for (size_t i = 0; i < vm->consts_count; i++)
-  {
-    if (vm->consts[i].type == FZL_CONSTTYPE_STRING)
-      free((void *)vm->consts[i].as.string.chars);
-  }
-
-  free(vm->consts);
-  free(vm->ops);
   free(vm);
 }