/*

   +----------------------------------------------------------------------+

   | Zend Engine, Func Info                                               |

   +----------------------------------------------------------------------+

   | Copyright © The PHP Group and Contributors.                          |

   +----------------------------------------------------------------------+

   | This source file is subject to the Modified BSD License that is      |

   | bundled with this package in the file LICENSE, and is available      |

   | through the World Wide Web at <https://www.php.net/license/>.        |

   |                                                                      |

   | SPDX-License-Identifier: BSD-3-Clause                                |

   +----------------------------------------------------------------------+

   | Authors: Dmitry Stogov <dmitry@php.net>                              |

   |          Xinchen Hui <laruence@php.net>                              |

   +----------------------------------------------------------------------+

*/

#include "zend_compile.h"

#include "zend_extensions.h"

#include "zend_ssa.h"

#include "zend_optimizer_internal.h"

#include "zend_inference.h"

#include "zend_call_graph.h"

#include "zend_func_info.h"

#ifdef _WIN32

#include "win32/ioutil.h"

#endif

typedef uint32_t (*info_func_t)(const zend_call_info *call_info, const zend_ssa *ssa);

typedef struct _func_info_t {

  const char *name;

  unsigned    name_len;

  uint32_t    info;

  info_func_t info_func;

} func_info_t;

#define F0(name, info) \

  {name, sizeof(name)-1, (info), NULL}

#define F1(name, info) \

  {name, sizeof(name)-1, (MAY_BE_RC1 | (info)), NULL}

#define FN(name, info) \

  {name, sizeof(name)-1, (MAY_BE_RC1 | MAY_BE_RCN | (info)), NULL}

#define FC(name, callback) \

  {name, sizeof(name)-1, 0, callback}

#include "zend_func_infos.h"

static uint32_t zend_range_info(const zend_call_info *call_info, const zend_ssa *ssa)

{

  ZEND_ASSERT(!call_info->is_frameless);

  if (!call_info->send_unpack

   && (call_info->num_args == 2 || call_info->num_args == 3)

   && ssa

   && !(ssa->cfg.flags & ZEND_SSA_TSSA)) {

    const zend_op_array *op_array = call_info->caller_op_array;

    uint32_t t1 = _ssa_op1_info(op_array, ssa, call_info->arg_info[0].opline,

      ssa->ops ? &ssa->ops[call_info->arg_info[0].opline - op_array->opcodes] : NULL);

    uint32_t t2 = _ssa_op1_info(op_array, ssa, call_info->arg_info[1].opline,

      ssa->ops ? &ssa->ops[call_info->arg_info[1].opline - op_array->opcodes] : NULL);

    uint32_t t3 = 0;

    uint32_t tmp = MAY_BE_RC1 | MAY_BE_ARRAY;

    if (call_info->num_args == 3) {

      t3 = _ssa_op1_info(op_array, ssa, call_info->arg_info[2].opline,

        ssa->ops ? &ssa->ops[call_info->arg_info[2].opline - op_array->opcodes] : NULL);

    }

    if ((t1 & MAY_BE_STRING) && (t2 & MAY_BE_STRING)) {

      tmp |= MAY_BE_ARRAY_OF_LONG | MAY_BE_ARRAY_OF_DOUBLE | MAY_BE_ARRAY_OF_STRING;

    }

    if ((t1 & (MAY_BE_DOUBLE|MAY_BE_STRING))

        || (t2 & (MAY_BE_DOUBLE|MAY_BE_STRING))

        || (t3 & (MAY_BE_DOUBLE|MAY_BE_STRING))) {

      tmp |= MAY_BE_ARRAY_OF_DOUBLE;

    }

    if ((t1 & ((MAY_BE_ANY|MAY_BE_UNDEF)-MAY_BE_DOUBLE))

        && (t2 & ((MAY_BE_ANY|MAY_BE_UNDEF)-MAY_BE_DOUBLE))) {

      tmp |= MAY_BE_ARRAY_OF_LONG;

    }

    if (tmp & MAY_BE_ARRAY_OF_ANY) {

      tmp |= MAY_BE_ARRAY_PACKED;

    }

    return tmp;

  } else {

    /* May throw */

    return MAY_BE_RC1 | MAY_BE_ARRAY | MAY_BE_ARRAY_EMPTY | MAY_BE_ARRAY_PACKED | MAY_BE_ARRAY_OF_LONG | MAY_BE_ARRAY_OF_DOUBLE | MAY_BE_ARRAY_OF_STRING;

  }

}

static const func_info_t old_func_infos[] = {

  FC("range",                        zend_range_info),

};

static HashTable func_info;

ZEND_API int zend_func_info_rid = -1;

uint32_t zend_get_internal_func_info(

    const zend_function *callee_func, const zend_call_info *call_info, const zend_ssa *ssa) {

  if (callee_func->common.scope) {

    /* This is a method, not a function. */

    return 0;

  }

  zend_string *name = callee_func->common.function_name;

  if (!name) {

    /* zend_pass_function has no name. */

    return 0;

  }

  zval *zv = zend_hash_find_known_hash(&func_info, name);

  if (!zv) {

    return 0;

  }

  const func_info_t *info = Z_PTR_P(zv);

  if (info->info_func) {

    return call_info ? info->info_func(call_info, ssa) : 0;

  } else {

    uint32_t ret = info->info;

    if (ret & MAY_BE_ARRAY) {

      ret |= MAY_BE_ARRAY_EMPTY;

    }

    return ret;

  }

}

ZEND_API uint32_t zend_get_func_info(

    const zend_call_info *call_info, const zend_ssa *ssa,

    zend_class_entry **ce, bool *ce_is_instanceof)

{

  uint32_t ret = 0;

  const zend_function *callee_func = call_info->callee_func;

  *ce = NULL;

  *ce_is_instanceof = false;

  if (callee_func->type == ZEND_INTERNAL_FUNCTION) {

    uint32_t internal_ret = zend_get_internal_func_info(callee_func, call_info, ssa);

#if !ZEND_DEBUG

    if (internal_ret) {

      return internal_ret;

    }

#endif

    ret = zend_get_return_info_from_signature_only(

      callee_func, /* script */ NULL, ce, ce_is_instanceof, /* use_tentative_return_info */ !call_info->is_prototype);

#if ZEND_DEBUG

    if (internal_ret) {

      zend_string *name = callee_func->common.function_name;

      /* Check whether the func_info information is a subset of the information we can

       * compute from the specified return type, otherwise it contains redundant types. */

      if (internal_ret & ~ret) {

        fprintf(stderr, "Inaccurate func info for %s()\n", ZSTR_VAL(name));

      }

      /* Check whether the func info is completely redundant with arginfo. */

      if (internal_ret == ret) {

        fprintf(stderr, "Useless func info for %s()\n", ZSTR_VAL(name));

      }

      /* If the return type is not mixed, check that the types match exactly if we exclude

       * RC and array information. */

      uint32_t ret_any = ret & MAY_BE_ANY, internal_ret_any = internal_ret & MAY_BE_ANY;

      if (ret_any != MAY_BE_ANY) {

        uint32_t diff = internal_ret_any ^ ret_any;

        /* Func info may contain "true" types as well as isolated "null" and "false". */

        if (diff && !(diff == MAY_BE_FALSE && (ret & MAY_BE_FALSE))

            && (internal_ret_any & ~(MAY_BE_NULL|MAY_BE_FALSE))) {

          fprintf(stderr, "Incorrect func info for %s()\n", ZSTR_VAL(name));

        }

      }

      return internal_ret;

    }

#endif

  } else {

    if (!call_info->is_prototype) {

      // FIXME: the order of functions matters!!!

      const zend_func_info *info = ZEND_FUNC_INFO((zend_op_array*)callee_func);

      if (info) {

        ret = info->return_info.type;

        *ce = info->return_info.ce;

        *ce_is_instanceof = info->return_info.is_instanceof;

      }

    }

    if (!ret) {

      ret = zend_get_return_info_from_signature_only(

        callee_func, /* TODO: script */ NULL, ce, ce_is_instanceof, /* use_tentative_return_info */ !call_info->is_prototype);

      /* It's allowed to override a method that return non-reference with a method that returns a reference */

      if (call_info->is_prototype && (ret & ~MAY_BE_REF)) {

        ret |= MAY_BE_REF;

        *ce = NULL;

      }

    }

  }

  return ret;

}

static void zend_func_info_add(const func_info_t *new_func_infos, size_t n)

{

  for (size_t i = 0; i < n; i++) {

    zend_string *key = zend_string_init_interned(new_func_infos[i].name, new_func_infos[i].name_len, 1);

    if (zend_hash_add_ptr(&func_info, key, (void**)&new_func_infos[i]) == NULL) {

      fprintf(stderr, "ERROR: Duplicate function info for \"%s\"\n", new_func_infos[i].name);

    }

    zend_string_release_ex(key, 1);

  }

}

zend_result zend_func_info_startup(void)

{

  if (zend_func_info_rid == -1) {

    zend_func_info_rid = zend_get_resource_handle("Zend Optimizer");

    if (zend_func_info_rid < 0) {

      return FAILURE;

    }

    zend_hash_init(&func_info, sizeof(old_func_infos)/sizeof(func_info_t) + sizeof(func_infos)/sizeof(func_info_t), NULL, NULL, 1);

    zend_func_info_add(old_func_infos, sizeof(old_func_infos)/sizeof(func_info_t));

    zend_func_info_add(func_infos, sizeof(func_infos)/sizeof(func_info_t));

  }

  return SUCCESS;

}

zend_result zend_func_info_shutdown(void)

{

  if (zend_func_info_rid != -1) {

    zend_hash_destroy(&func_info);

    zend_func_info_rid = -1;

  }

  return SUCCESS;

}