text: /*
   * Copyright (c) 2009-2016 Petri Lehtinen <petri@digip.org>
   * Copyright (c) 2011-2012 Graeme Smecher <graeme.smecher@mail.mcgill.ca>
   *
   * Jansson is free software; you can redistribute it and/or modify
   * it under the terms of the MIT license. See LICENSE for details.
   */
  
  #include <string.h>
  #include "jansson.h"
  #include "jansson_private.h"
  #include "utf.h"
  
  typedef struct
  {
      int line;
      int column;
      size_t pos;
      char token;
  } token_t;
  
  typedef struct
  {
      const char *start;
      const char *fmt;
      token_t prev_token;
      token_t token;
      token_t next_token;
      json_error_t *error;
      size_t flags;
      int line;
      int column;
      size_t pos;
  } scanner_t;
  
  #define token(scanner) ((scanner)->token.token)
  
  static const char * const type_names[] =
  {
      "object",
      "array",
      "string",
      "integer",
      "real",
      "true",
      "false",
      "null"
  };
  
  #define type_name(x) type_names[json_typeof(x)]
  
  static const char unpack_value_starters[] = "{[siIbfFOon";
  
  static void scanner_init(scanner_t *s, json_error_t *error,
                           size_t flags, const char *fmt)
  {
      s->error = error;
      s->flags = flags;
      s->fmt = s->start = fmt;
      memset(&s->prev_token, 0, sizeof(token_t));
      memset(&s->token, 0, sizeof(token_t));
      memset(&s->next_token, 0, sizeof(token_t));
      s->line = 1;
      s->column = 0;
      s->pos = 0;
  }
  
  static void next_token(scanner_t *s)
  {
      const char *t;
      s->prev_token = s->token;
  
      if(s->next_token.line)
      {
          s->token = s->next_token;
          s->next_token.line = 0;
          return;
      }
  
      t = s->fmt;
      s->column++;
      s->pos++;
  
      /* skip space and ignored chars */
      while(*t == ' ' || *t == '\t' || *t == '\n' || *t == ',' || *t == ':')
      {
          if(*t == '\n')
          {
              s->line++;
              s->column = 1;
          }
          else
              s->column++;
  
          s->pos++;
          t++;
      }
  
      s->token.token = *t;
      s->token.line = s->line;
      s->token.column = s->column;
      s->token.pos = s->pos;
  
      t++;
      s->fmt = t;
  }
  
  static void prev_token(scanner_t *s)
  {
      s->next_token = s->token;
      s->token = s->prev_token;
  }
  
  static void set_error(scanner_t *s, const char *source, const char *fmt, ...)
  {
      va_list ap;
      va_start(ap, fmt);
  
      jsonp_error_vset(s->error, s->token.line, s->token.column, s->token.pos,
                       fmt, ap);
  
      jsonp_error_set_source(s->error, source);
  
      va_end(ap);
  }
  
  static json_t *pack(scanner_t *s, va_list *ap);
  
  
  /* ours will be set to 1 if jsonp_free() must be called for the result
     afterwards */
  static char *read_string(scanner_t *s, va_list *ap,
                           const char *purpose, size_t *out_len, int *ours)
  {
      char t;
      strbuffer_t strbuff;
      const char *str;
      size_t length;
  
      next_token(s);
      t = token(s);
      prev_token(s);
  
      if(t != '#' && t != '%' && t != '+')
      {
          /* Optimize the simple case */
          str = va_arg(*ap, const char *);
  
          if(!str)
          {
              set_error(s, "<args>", "NULL string argument");
              return NULL;
          }
  
          length = strlen(str);
  
          if(!utf8_check_string(str, length))
          {
              set_error(s, "<args>", "Invalid UTF-8 %s", purpose);
              return NULL;
          }
  
          *out_len = length;
          *ours = 0;
          return (char *)str;
      }
  
      strbuffer_init(&strbuff);
  
      while(1)
      {
          str = va_arg(*ap, const char *);
          if(!str)
          {
              set_error(s, "<args>", "NULL string argument");
              strbuffer_close(&strbuff);
              return NULL;
          }
  
          next_token(s);
  
          if(token(s) == '#')
          {
              length = va_arg(*ap, int);
          }
          else if(token(s) == '%')
          {
              length = va_arg(*ap, size_t);
          }
          else
          {
              prev_token(s);
              length = strlen(str);
          }
  
          if(strbuffer_append_bytes(&strbuff, str, length) == -1)
          {
              set_error(s, "<internal>", "Out of memory");
              strbuffer_close(&strbuff);
              return NULL;
          }
  
          next_token(s);
          if(token(s) != '+')
          {
              prev_token(s);
              break;
          }
      }
  
      if(!utf8_check_string(strbuff.value, strbuff.length))
      {
          set_error(s, "<args>", "Invalid UTF-8 %s", purpose);
          strbuffer_close(&strbuff);
          return NULL;
      }
  
      *out_len = strbuff.length;
      *ours = 1;
      return strbuffer_steal_value(&strbuff);
  }
  
  static json_t *pack_object(scanner_t *s, va_list *ap)
  {
      json_t *object = json_object();
      next_token(s);
  
      while(token(s) != '}')
      {
          char *key;
          size_t len;
          int ours;
          json_t *value;
  
          if(!token(s))
          {
              set_error(s, "<format>", "Unexpected end of format string");
              goto error;
          }
  
          if(token(s) != 's')
          {
              set_error(s, "<format>", "Expected format 's', got '%c'", token(s));
              goto error;
          }
  
          key = read_string(s, ap, "object key", &len, &ours);
          if(!key)
              goto error;
  
          next_token(s);
  
          value = pack(s, ap);
          if(!value)
          {
              if(ours)
                  jsonp_free(key);
  
              goto error;
          }
  
          if(json_object_set_new_nocheck(object, key, value))
          {
              set_error(s, "<internal>", "Unable to add key \"%s\"", key);
              if(ours)
                  jsonp_free(key);
  
              goto error;
          }
  
          if(ours)
              jsonp_free(key);
  
          next_token(s);
      }
  
      return object;
  
  error:
      json_decref(object);
      return NULL;
  }
  
  static json_t *pack_array(scanner_t *s, va_list *ap)
  {
      json_t *array = json_array();
      next_token(s);
  
      while(token(s) != ']')
      {
          json_t *value;
  
          if(!token(s))
          {
              set_error(s, "<format>", "Unexpected end of format string");
              goto error;
          }
  
          value = pack(s, ap);
          if(!value)
              goto error;
  
          if(json_array_append_new(array, value))
          {
              set_error(s, "<internal>", "Unable to append to array");
              goto error;
          }
  
          next_token(s);
      }
      return array;
  
  error:
      json_decref(array);
      return NULL;
  }
  
  static json_t *pack_string(scanner_t *s, va_list *ap)
  {
      char *str;
      size_t len;
      int ours;
      int nullable;
  
      next_token(s);
      nullable = token(s) == '?';
      if (!nullable)
          prev_token(s);
  
      str = read_string(s, ap, "string", &len, &ours);
      if (!str)
      {
          return nullable ? json_null() : NULL;
      }
      else if (ours)
      {
          return jsonp_stringn_nocheck_own(str, len);
      }
      else
      {
          return json_stringn_nocheck(str, len);
      }
  }
  
  static json_t *pack(scanner_t *s, va_list *ap)
  {
      switch(token(s))
      {
          case '{':
              return pack_object(s, ap);
  
          case '[':
              return pack_array(s, ap);
  
          case 's': /* string */
              return pack_string(s, ap);
  
          case 'n': /* null */
              return json_null();
  
          case 'b': /* boolean */
              return va_arg(*ap, int) ? json_true() : json_false();
  
          case 'i': /* integer from int */
              return json_integer(va_arg(*ap, int));
  
          case 'I': /* integer from json_int_t */
              return json_integer(va_arg(*ap, json_int_t));
  
          case 'f': /* real */
              return json_real(va_arg(*ap, double));
  
          case 'O': /* a json_t object; increments refcount */
          {
              int nullable;
              json_t *json;
  
              next_token(s);
              nullable = token(s) == '?';
              if (!nullable)
                  prev_token(s);
  
              json = va_arg(*ap, json_t *);
              if (!json && nullable)
              {
                  return json_null();
              }
              else
              {
                  return json_incref(json);
              }
          }
  
          case 'o': /* a json_t object; doesn't increment refcount */
          {
              int nullable;
              json_t *json;
  
              next_token(s);
              nullable = token(s) == '?';
              if (!nullable)
                  prev_token(s);
  
              json = va_arg(*ap, json_t *);
              if (!json && nullable)
              {
                  return json_null();
              }
              else
              {
                  return json;
              }
          }
  
          default:
              set_error(s, "<format>", "Unexpected format character '%c'",
                        token(s));
              return NULL;
      }
  }
  
  static int unpack(scanner_t *s, json_t *root, va_list *ap);
  
  static int unpack_object(scanner_t *s, json_t *root, va_list *ap)
  {
      int ret = -1;
      int strict = 0;
      int gotopt = 0;
  
      /* Use a set (emulated by a hashtable) to check that all object
         keys are accessed. Checking that the correct number of keys
         were accessed is not enough, as the same key can be unpacked
         multiple times.
      */
      hashtable_t key_set;
  
      if(hashtable_init(&key_set))
      {
          set_error(s, "<internal>", "Out of memory");
          return -1;
      }
  
      if(root && !json_is_object(root))
      {
          set_error(s, "<validation>", "Expected object, got %s",
                    type_name(root));
          goto out;
      }
      next_token(s);
  
      while(token(s) != '}')
      {
          const char *key;
          json_t *value;
          int opt = 0;
  
          if(strict != 0)
          {
              set_error(s, "<format>", "Expected '}' after '%c', got '%c'",
                        (strict == 1 ? '!' : '*'), token(s));
              goto out;
          }
  
          if(!token(s))
          {
              set_error(s, "<format>", "Unexpected end of format string");
              goto out;
          }
  
          if(token(s) == '!' || token(s) == '*')
          {
              strict = (token(s) == '!' ? 1 : -1);
              next_token(s);
              continue;
          }
  
          if(token(s) != 's')
          {
              set_error(s, "<format>", "Expected format 's', got '%c'", token(s));
              goto out;
          }
  
          key = va_arg(*ap, const char *);
          if(!key)
          {
              set_error(s, "<args>", "NULL object key");
              goto out;
          }
  
          next_token(s);
  
          if(token(s) == '?')
          {
              opt = gotopt = 1;
              next_token(s);
          }
  
          if(!root)
          {
              /* skipping */
              value = NULL;
          }
          else
          {
              value = json_object_get(root, key);
              if(!value && !opt)
              {
                  set_error(s, "<validation>", "Object item not found: %s", key);
                  goto out;
              }
          }
  
          if(unpack(s, value, ap))
              goto out;
  
          hashtable_set(&key_set, key, json_null());
          next_token(s);
      }
  
      if(strict == 0 && (s->flags & JSON_STRICT))
          strict = 1;
  
      if(root && strict == 1)
      {
          /* We need to check that all non optional items have been parsed */
          const char *key;
          int have_unrecognized_keys = 0;
          strbuffer_t unrecognized_keys;
          json_t *value;
          long unpacked = 0;
          if (gotopt)
          {
              /* We have optional keys, we need to iter on each key */
              json_object_foreach(root, key, value)
              {
                  if(!hashtable_get(&key_set, key))
                  {
                      unpacked++;
  
                      /* Save unrecognized keys for the error message */
                      if (!have_unrecognized_keys)
                      {
                          strbuffer_init(&unrecognized_keys);
                          have_unrecognized_keys = 1;
                      }
                      else
                      {
                          strbuffer_append_bytes(&unrecognized_keys, ", ", 2);
                      }
                      strbuffer_append_bytes(&unrecognized_keys, key, strlen(key));
                  }
              }
          }
          else
          {
              /* No optional keys, we can just compare the number of items */
              unpacked = (long)json_object_size(root) - (long)key_set.size;
          }
          if (unpacked)
          {
              if (!gotopt)
              {
                  /* Save unrecognized keys for the error message */
                  json_object_foreach(root, key, value)
                  {
                      if(!hashtable_get(&key_set, key))
                      {
                          if (!have_unrecognized_keys)
                          {
                              strbuffer_init(&unrecognized_keys);
                              have_unrecognized_keys = 1;
                          }
                          else
                          {
                              strbuffer_append_bytes(&unrecognized_keys, ", ", 2);
                          }
                          strbuffer_append_bytes(&unrecognized_keys, key, strlen(key));
                      }
                  }
              }
              set_error(s, "<validation>",
                        "%li object item(s) left unpacked: %s",
                        unpacked, strbuffer_value(&unrecognized_keys));
              strbuffer_close(&unrecognized_keys);
              goto out;
          }
      }
  
      ret = 0;
  
  out:
      hashtable_close(&key_set);
      return ret;
  }
  
  static int unpack_array(scanner_t *s, json_t *root, va_list *ap)
  {
      size_t i = 0;
      int strict = 0;
  
      if(root && !json_is_array(root))
      {
          set_error(s, "<validation>", "Expected array, got %s", type_name(root));
          return -1;
      }
      next_token(s);
  
      while(token(s) != ']')
      {
          json_t *value;
  
          if(strict != 0)
          {
              set_error(s, "<format>", "Expected ']' after '%c', got '%c'",
                        (strict == 1 ? '!' : '*'),
                        token(s));
              return -1;
          }
  
          if(!token(s))
          {
              set_error(s, "<format>", "Unexpected end of format string");
              return -1;
          }
  
          if(token(s) == '!' || token(s) == '*')
          {
              strict = (token(s) == '!' ? 1 : -1);
              next_token(s);
              continue;
          }
  
          if(!strchr(unpack_value_starters, token(s)))
          {
              set_error(s, "<format>", "Unexpected format character '%c'",
                        token(s));
              return -1;
          }
  
          if(!root)
          {
              /* skipping */
              value = NULL;
          }
          else
          {
              value = json_array_get(root, i);
              if(!value)
              {
                  set_error(s, "<validation>", "Array index %lu out of range",
                            (unsigned long)i);
                  return -1;
              }
          }
  
          if(unpack(s, value, ap))
              return -1;
  
          next_token(s);
          i++;
      }
  
      if(strict == 0 && (s->flags & JSON_STRICT))
          strict = 1;
  
      if(root && strict == 1 && i != json_array_size(root))
      {
          long diff = (long)json_array_size(root) - (long)i;
          set_error(s, "<validation>", "%li array item(s) left unpacked", diff);
          return -1;
      }
  
      return 0;
  }
  
  static int unpack(scanner_t *s, json_t *root, va_list *ap)
  {
      switch(token(s))
      {
          case '{':
              return unpack_object(s, root, ap);
  
          case '[':
              return unpack_array(s, root, ap);
  
          case 's':
              if(root && !json_is_string(root))
              {
                  set_error(s, "<validation>", "Expected string, got %s",
                            type_name(root));
                  return -1;
              }
  
              if(!(s->flags & JSON_VALIDATE_ONLY))
              {
                  const char **str_target;
                  size_t *len_target = NULL;
  
                  str_target = va_arg(*ap, const char **);
                  if(!str_target)
                  {
                      set_error(s, "<args>", "NULL string argument");
                      return -1;
                  }
  
                  next_token(s);
  
                  if(token(s) == '%')
                  {
                      len_target = va_arg(*ap, size_t *);
                      if(!len_target)
                      {
                          set_error(s, "<args>", "NULL string length argument");
                          return -1;
                      }
                  }
                  else
                      prev_token(s);
  
                  if(root)
                  {
                      *str_target = json_string_value(root);
                      if(len_target)
                          *len_target = json_string_length(root);
                  }
              }
              return 0;
  
          case 'i':
              if(root && !json_is_integer(root))
              {
                  set_error(s, "<validation>", "Expected integer, got %s",
                            type_name(root));
                  return -1;
              }
  
              if(!(s->flags & JSON_VALIDATE_ONLY))
              {
                  int *target = va_arg(*ap, int*);
                  if(root)
                      *target = (int)json_integer_value(root);
              }
  
              return 0;
  
          case 'I':
              if(root && !json_is_integer(root))
              {
                  set_error(s, "<validation>", "Expected integer, got %s",
                            type_name(root));
                  return -1;
              }
  
              if(!(s->flags & JSON_VALIDATE_ONLY))
              {
                  json_int_t *target = va_arg(*ap, json_int_t*);
                  if(root)
                      *target = json_integer_value(root);
              }
  
              return 0;
  
          case 'b':
              if(root && !json_is_boolean(root))
              {
                  set_error(s, "<validation>", "Expected true or false, got %s",
                            type_name(root));
                  return -1;
              }
  
              if(!(s->flags & JSON_VALIDATE_ONLY))
              {
                  int *target = va_arg(*ap, int*);
                  if(root)
                      *target = json_is_true(root);
              }
  
              return 0;
  
          case 'f':
              if(root && !json_is_real(root))
              {
                  set_error(s, "<validation>", "Expected real, got %s",
                            type_name(root));
                  return -1;
              }
  
              if(!(s->flags & JSON_VALIDATE_ONLY))
              {
                  double *target = va_arg(*ap, double*);
                  if(root)
                      *target = json_real_value(root);
              }
  
              return 0;
  
          case 'F':
              if(root && !json_is_number(root))
              {
                  set_error(s, "<validation>", "Expected real or integer, got %s",
                            type_name(root));
                  return -1;
              }
  
              if(!(s->flags & JSON_VALIDATE_ONLY))
              {
                  double *target = va_arg(*ap, double*);
                  if(root)
                      *target = json_number_value(root);
              }
  
              return 0;
  
          case 'O':
              if(root && !(s->flags & JSON_VALIDATE_ONLY))
                  json_incref(root);
          /* Fall through */
  
          case 'o':
              if(!(s->flags & JSON_VALIDATE_ONLY))
              {
                  json_t **target = va_arg(*ap, json_t**);
                  if(root)
                      *target = root;
              }
  
              return 0;
  
          case 'n':
              /* Never assign, just validate */
              if(root && !json_is_null(root))
              {
                  set_error(s, "<validation>", "Expected null, got %s",
                            type_name(root));
                  return -1;
              }
              return 0;
  
          default:
              set_error(s, "<format>", "Unexpected format character '%c'",
                        token(s));
              return -1;
      }
  }
  
  json_t *json_vpack_ex(json_error_t *error, size_t flags,
                        const char *fmt, va_list ap)
  {
      scanner_t s;
      va_list ap_copy;
      json_t *value;
  
      if(!fmt || !*fmt)
      {
          jsonp_error_init(error, "<format>");
          jsonp_error_set(error, -1, -1, 0, "NULL or empty format string");
          return NULL;
      }
      jsonp_error_init(error, NULL);
  
      scanner_init(&s, error, flags, fmt);
      next_token(&s);
  
      va_copy(ap_copy, ap);
      value = pack(&s, &ap_copy);
      va_end(ap_copy);
  
      if(!value)
          return NULL;
  
      next_token(&s);
      if(token(&s))
      {
          json_decref(value);
          set_error(&s, "<format>", "Garbage after format string");
          return NULL;
      }
  
      return value;
  }
  
  json_t *json_pack_ex(json_error_t *error, size_t flags, const char *fmt, ...)
  {
      json_t *value;
      va_list ap;
  
      va_start(ap, fmt);
      value = json_vpack_ex(error, flags, fmt, ap);
      va_end(ap);
  
      return value;
  }
  
  json_t *json_pack(const char *fmt, ...)
  {
      json_t *value;
      va_list ap;
  
      va_start(ap, fmt);
      value = json_vpack_ex(NULL, 0, fmt, ap);
      va_end(ap);
  
      return value;
  }
  
  int json_vunpack_ex(json_t *root, json_error_t *error, size_t flags,
                      const char *fmt, va_list ap)
  {
      scanner_t s;
      va_list ap_copy;
  
      if(!root)
      {
          jsonp_error_init(error, "<root>");
          jsonp_error_set(error, -1, -1, 0, "NULL root value");
          return -1;
      }
  
      if(!fmt || !*fmt)
      {
          jsonp_error_init(error, "<format>");
          jsonp_error_set(error, -1, -1, 0, "NULL or empty format string");
          return -1;
      }
      jsonp_error_init(error, NULL);
  
      scanner_init(&s, error, flags, fmt);
      next_token(&s);
  
      va_copy(ap_copy, ap);
      if(unpack(&s, root, &ap_copy))
      {
          va_end(ap_copy);
          return -1;
      }
      va_end(ap_copy);
  
      next_token(&s);
      if(token(&s))
      {
          set_error(&s, "<format>", "Garbage after format string");
          return -1;
      }
  
      return 0;
  }
  
  int json_unpack_ex(json_t *root, json_error_t *error, size_t flags, const char *fmt, ...)
  {
      int ret;
      va_list ap;
  
      va_start(ap, fmt);
      ret = json_vunpack_ex(root, error, flags, fmt, ap);
      va_end(ap);
  
      return ret;
  }
  
  int json_unpack(json_t *root, const char *fmt, ...)
  {
      int ret;
      va_list ap;
  
      va_start(ap, fmt);
      ret = json_vunpack_ex(root, NULL, 0, fmt, ap);
      va_end(ap);
  
      return ret;
  }
  