/src/php-src/Zend/zend_exceptions.c

Source
/*
   +----------------------------------------------------------------------+
   | Zend Engine                                                          |
   +----------------------------------------------------------------------+
   | Copyright © Zend Technologies Ltd., a subsidiary company of          |
   |     Perforce Software, Inc., 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: Andi Gutmans <andi@php.net>                                 |
   |          Marcus Boerger <helly@php.net>                              |
   |          Sterling Hughes <sterling@php.net>                          |
   |          Zeev Suraski <zeev@php.net>                                 |
   +----------------------------------------------------------------------+
*/

#include "zend.h"
#include "zend_API.h"
#include "zend_builtin_functions.h"
#include "zend_interfaces.h"
#include "zend_exceptions.h"
#include "zend_vm.h"
#include "zend_dtrace.h"
#include "zend_smart_str.h"
#include "zend_exceptions_arginfo.h"
#include "zend_observer.h"

#define ZEND_EXCEPTION_MESSAGE_OFF 0
#define ZEND_EXCEPTION_CODE_OFF 2
#define ZEND_EXCEPTION_FILE_OFF 3
#define ZEND_EXCEPTION_LINE_OFF 4
#define ZEND_EXCEPTION_TRACE_OFF 5
#define ZEND_EXCEPTION_PREVIOUS_OFF 6

ZEND_API zend_class_entry *zend_ce_throwable;
ZEND_API zend_class_entry *zend_ce_exception;
ZEND_API zend_class_entry *zend_ce_error_exception;
ZEND_API zend_class_entry *zend_ce_error;
ZEND_API zend_class_entry *zend_ce_compile_error;
ZEND_API zend_class_entry *zend_ce_parse_error;
ZEND_API zend_class_entry *zend_ce_type_error;
ZEND_API zend_class_entry *zend_ce_argument_count_error;
ZEND_API zend_class_entry *zend_ce_value_error;
ZEND_API zend_class_entry *zend_ce_arithmetic_error;
ZEND_API zend_class_entry *zend_ce_division_by_zero_error;
ZEND_API zend_class_entry *zend_ce_unhandled_match_error;
ZEND_API zend_class_entry *zend_ce_request_parse_body_exception;

/* Internal pseudo-exception that is not exposed to userland. Throwing this exception *does not* execute finally blocks. */
static zend_class_entry zend_ce_unwind_exit;

/* Internal pseudo-exception that is not exposed to userland. Throwing this exception *does* execute finally blocks. */
static zend_class_entry zend_ce_graceful_exit;

ZEND_API void (*zend_throw_exception_hook)(zend_object *ex);

static zend_object_handlers default_exception_handlers;

/* {{{ zend_implement_throwable */
static int zend_implement_throwable(zend_class_entry *interface, zend_class_entry *class_type)
{
  /* zend_ce_exception and zend_ce_error may not be initialized yet when this is called (e.g when
   * implementing Throwable for Exception itself). Perform a manual inheritance check. */
  const zend_class_entry *root = class_type;
  while (root->parent) {
    root = root->parent;
  }
  if (zend_string_equals_literal(root->name, "Exception")
      || zend_string_equals_literal(root->name, "Error")) {
    return SUCCESS;
  }

  bool can_extend = (class_type->ce_flags & ZEND_ACC_ENUM) == 0;

  zend_error_noreturn(E_ERROR,
    can_extend
      ? "%s %s cannot implement interface %s, extend Exception or Error instead"
      : "%s %s cannot implement interface %s",
    zend_get_object_type_uc(class_type),
    ZSTR_VAL(class_type->name),
    ZSTR_VAL(interface->name));
  return FAILURE;
}
/* }}} */

static inline zend_class_entry *i_get_exception_base(const zend_object *object) /* {{{ */
{
  return instanceof_function(object->ce, zend_ce_exception) ? zend_ce_exception : zend_ce_error;
}
/* }}} */

ZEND_API zend_class_entry *zend_get_exception_base(const zend_object *object) /* {{{ */
{
  return i_get_exception_base(object);
}
/* }}} */

void zend_exception_set_previous(zend_object *exception, zend_object *add_previous) /* {{{ */
{
  zval *previous, *ancestor, *ex;
  zval  pv, zv, rv;
  zend_class_entry *base_ce;

  if (!exception || !add_previous) {
    return;
  }

  if (exception == add_previous || zend_is_unwind_exit(add_previous) || zend_is_graceful_exit(add_previous)) {
    OBJ_RELEASE(add_previous);
    return;
  }

  ZEND_ASSERT(instanceof_function(add_previous->ce, zend_ce_throwable)
    && "Previous exception must implement Throwable");

  ZVAL_OBJ(&pv, add_previous);
  ZVAL_OBJ(&zv, exception);
  ex = &zv;
  do {
    ancestor = zend_read_property_ex(i_get_exception_base(add_previous), add_previous, ZSTR_KNOWN(ZEND_STR_PREVIOUS), 1, &rv);
    ZVAL_DEREF(ancestor);
    while (Z_TYPE_P(ancestor) == IS_OBJECT) {
      if (Z_OBJ_P(ancestor) == Z_OBJ_P(ex)) {
        OBJ_RELEASE(add_previous);
        return;
      }
      ancestor = zend_read_property_ex(i_get_exception_base(Z_OBJ_P(ancestor)), Z_OBJ_P(ancestor), ZSTR_KNOWN(ZEND_STR_PREVIOUS), 1, &rv);
      ZVAL_DEREF(ancestor);
    }
    base_ce = i_get_exception_base(Z_OBJ_P(ex));
    previous = zend_read_property_ex(base_ce, Z_OBJ_P(ex), ZSTR_KNOWN(ZEND_STR_PREVIOUS), 1, &rv);
    ZVAL_DEREF(previous);
    if (Z_TYPE_P(previous) == IS_NULL) {
      zend_update_property_ex(base_ce, Z_OBJ_P(ex), ZSTR_KNOWN(ZEND_STR_PREVIOUS), &pv);
      GC_DELREF(add_previous);
      return;
    }
    ex = previous;
  } while (Z_OBJ_P(ex) != add_previous);
}
/* }}} */

static zend_always_inline bool is_handle_exception_set(void) {
  zend_execute_data *execute_data = EG(current_execute_data);
  return !execute_data
    || !execute_data->func
    || !ZEND_USER_CODE(execute_data->func->common.type)
    || execute_data->opline->opcode == ZEND_HANDLE_EXCEPTION;
}

ZEND_API ZEND_COLD void zend_throw_exception_internal(zend_object *exception) /* {{{ */
{
#ifdef HAVE_DTRACE
  if (DTRACE_EXCEPTION_THROWN_ENABLED()) {
    if (exception != NULL) {
      DTRACE_EXCEPTION_THROWN(ZSTR_VAL(exception->ce->name));
    } else {
      DTRACE_EXCEPTION_THROWN(NULL);
    }
  }
#endif /* HAVE_DTRACE */

  if (exception != NULL) {
    const zend_object *previous = EG(exception);
    if (previous && zend_is_unwind_exit(previous)) {
      /* Don't replace unwinding exception with different exception. */
      OBJ_RELEASE(exception);
      return;
    }

    zend_exception_set_previous(exception, EG(exception));
    EG(exception) = exception;
    if (previous) {
      return;
    }
  }
  if (!EG(current_execute_data)) {
    if (exception && (exception->ce == zend_ce_parse_error || exception->ce == zend_ce_compile_error)) {
      return;
    }
    if (EG(exception)) {
      if (Z_TYPE(EG(user_exception_handler)) != IS_UNDEF
       && !zend_is_unwind_exit(EG(exception))
       && !zend_is_graceful_exit(EG(exception))) {
        zend_user_exception_handler();
        if (EG(exception)) {
          zend_exception_error(EG(exception), E_ERROR);
        }
        return;
      } else {
        zend_exception_error(EG(exception), E_ERROR);
      }
      zend_bailout();
    }
    zend_error_noreturn(E_CORE_ERROR, "Exception thrown without a stack frame");
  }

  if (zend_throw_exception_hook) {
    zend_throw_exception_hook(exception);
  }

  if (is_handle_exception_set()) {
    /* no need to rethrow the exception */
    return;
  }
  EG(opline_before_exception) = EG(current_execute_data)->opline;
  EG(current_execute_data)->opline = EG(exception_op);
}
/* }}} */

ZEND_API void zend_clear_exception(void) /* {{{ */
{
  zend_object *exception;
  if (!EG(exception)) {
    return;
  }
  /* exception may have destructor */
  exception = EG(exception);
  EG(exception) = NULL;
  OBJ_RELEASE(exception);
  if (EG(current_execute_data)) {
    EG(current_execute_data)->opline = EG(opline_before_exception);
  }
#if ZEND_DEBUG
  EG(opline_before_exception) = NULL;
#endif
}
/* }}} */

/* Same as writing to OBJ_PROP_NUM() when there are no hooks,
 * but checks the offset is correct when Zend is built in debug mode.
 * This is faster than going through the regular property write routine when the offset is known at compile time. */
static void zend_update_property_num_checked(zend_class_entry *scope, zend_object *object, uint32_t prop_num, zend_string *member, zval *value)
{
  if (UNEXPECTED(object->ce->num_hooked_props > 0)) {
    /* Property may have been overridden with a hook. */
    zend_update_property_ex(scope != NULL ? scope : object->ce, object, member, value);
    zval_ptr_dtor(value);
    return;
  }
#if ZEND_DEBUG
  const zend_class_entry *old_scope = EG(fake_scope);
  EG(fake_scope) = i_get_exception_base(object);
  const zend_property_info *prop_info = zend_get_property_info(object->ce, member, true);
  ZEND_ASSERT(OBJ_PROP_TO_NUM(prop_info->offset) == prop_num);
  EG(fake_scope) = old_scope;
#endif
  zval *zv = OBJ_PROP_NUM(object, prop_num);
  zval_ptr_safe_dtor(zv);
  ZVAL_COPY_VALUE(zv, value);
}

static zend_object *zend_default_exception_new(zend_class_entry *class_type) /* {{{ */
{
  zval tmp;
  zval trace;
  zend_string *filename;

  zend_object *object = zend_objects_new(class_type);
  object_properties_init(object, class_type);

  if (EG(current_execute_data)) {
    zend_fetch_debug_backtrace(&trace,
      0,
      EG(exception_ignore_args) ? DEBUG_BACKTRACE_IGNORE_ARGS : 0, 0);
  } else {
    ZVAL_EMPTY_ARRAY(&trace);
  }

  zend_update_property_num_checked(i_get_exception_base(object), object, ZEND_EXCEPTION_TRACE_OFF, ZSTR_KNOWN(ZEND_STR_TRACE), &trace);

  if (EXPECTED((class_type != zend_ce_parse_error && class_type != zend_ce_compile_error)
      || !(filename = zend_get_compiled_filename()))) {
    ZVAL_STRING(&tmp, zend_get_executed_filename());
    zend_update_property_num_checked(NULL, object, ZEND_EXCEPTION_FILE_OFF, ZSTR_KNOWN(ZEND_STR_FILE), &tmp);
    ZVAL_LONG(&tmp, zend_get_executed_lineno());
    zend_update_property_num_checked(NULL, object, ZEND_EXCEPTION_LINE_OFF, ZSTR_KNOWN(ZEND_STR_LINE), &tmp);
  } else {
    ZVAL_STR_COPY(&tmp, filename);
    zend_update_property_num_checked(NULL, object, ZEND_EXCEPTION_FILE_OFF, ZSTR_KNOWN(ZEND_STR_FILE), &tmp);
    ZVAL_LONG(&tmp, zend_get_compiled_lineno());
    zend_update_property_num_checked(NULL, object, ZEND_EXCEPTION_LINE_OFF, ZSTR_KNOWN(ZEND_STR_LINE), &tmp);
  }

  return object;
}
/* }}} */

/* {{{ Clone the exception object */
ZEND_COLD ZEND_METHOD(Exception, __clone)
{
  /* __clone() is private but this is reachable with reflection */
  zend_throw_exception(NULL, "Cannot clone object using __clone()", 0);
}
/* }}} */

ZEND_API zend_result zend_update_exception_properties(INTERNAL_FUNCTION_PARAMETERS, zend_string *message, zend_long code, zval *previous)
{
  zval tmp, *object = ZEND_THIS;

  if (message) {
    ZVAL_STR_COPY(&tmp, message);
    zend_update_property_num_checked(NULL, Z_OBJ_P(object), ZEND_EXCEPTION_MESSAGE_OFF, ZSTR_KNOWN(ZEND_STR_MESSAGE), &tmp);
    if (UNEXPECTED(EG(exception))) {
      return FAILURE;
    }
  }

  if (code) {
    ZVAL_LONG(&tmp, code);
    zend_update_property_num_checked(NULL, Z_OBJ_P(object), ZEND_EXCEPTION_CODE_OFF, ZSTR_KNOWN(ZEND_STR_CODE), &tmp);
    if (UNEXPECTED(EG(exception))) {
      return FAILURE;
    }
  }

  if (previous) {
    Z_ADDREF_P(previous);
    zend_update_property_num_checked(zend_ce_exception, Z_OBJ_P(object), ZEND_EXCEPTION_PREVIOUS_OFF, ZSTR_KNOWN(ZEND_STR_PREVIOUS), previous);
    if (UNEXPECTED(EG(exception))) {
      return FAILURE;
    }
  }

  return SUCCESS;
}

/* {{{ Exception constructor */
ZEND_METHOD(Exception, __construct)
{
  zend_string *message = NULL;
  zend_long   code = 0;
  zval *previous = NULL;

  if (zend_parse_parameters(ZEND_NUM_ARGS(), "|SlO!", &message, &code, &previous, zend_ce_throwable) == FAILURE) {
    RETURN_THROWS();
  }

  if (zend_update_exception_properties(INTERNAL_FUNCTION_PARAM_PASSTHRU, message, code, previous) == FAILURE) {
    RETURN_THROWS();
  }
}
/* }}} */

/* {{{ Exception unserialize checks */
#define CHECK_EXC_TYPE(id, type) \
  pvalue = zend_read_property_ex(i_get_exception_base(Z_OBJ_P(object)), Z_OBJ_P(object), ZSTR_KNOWN(id), 1, &value); \
  if (Z_TYPE_P(pvalue) != IS_NULL && Z_TYPE_P(pvalue) != type) { \
    zend_unset_property(i_get_exception_base(Z_OBJ_P(object)), Z_OBJ_P(object), ZSTR_VAL(ZSTR_KNOWN(id)), ZSTR_LEN(ZSTR_KNOWN(id))); \
  }

ZEND_METHOD(Exception, __wakeup)
{
  ZEND_PARSE_PARAMETERS_NONE();

  zval value, *pvalue;
  zval *object = ZEND_THIS;
  CHECK_EXC_TYPE(ZEND_STR_MESSAGE, IS_STRING);
  CHECK_EXC_TYPE(ZEND_STR_CODE,    IS_LONG);
  /* The type of all other properties is enforced through typed properties. */
}
/* }}} */

/* {{{ ErrorException constructor */
ZEND_METHOD(ErrorException, __construct)
{
  zend_string *message = NULL, *filename = NULL;
  zend_long   code = 0, severity = E_ERROR, lineno;
  bool lineno_is_null = true;
  zval   tmp, *object, *previous = NULL;

  if (zend_parse_parameters(ZEND_NUM_ARGS(), "|SllS!l!O!", &message, &code, &severity, &filename, &lineno, &lineno_is_null, &previous, zend_ce_throwable) == FAILURE) {
    RETURN_THROWS();
  }

  object = ZEND_THIS;

  if (zend_update_exception_properties(INTERNAL_FUNCTION_PARAM_PASSTHRU, message, code, previous) == FAILURE) {
    RETURN_THROWS();
  }

  ZVAL_LONG(&tmp, severity);
  zend_update_property_ex(zend_ce_exception, Z_OBJ_P(object), ZSTR_KNOWN(ZEND_STR_SEVERITY), &tmp);
  if (UNEXPECTED(EG(exception))) {
    RETURN_THROWS();
  }

  if (filename) {
    ZVAL_STR_COPY(&tmp, filename);
    zend_update_property_num_checked(NULL, Z_OBJ_P(object), ZEND_EXCEPTION_FILE_OFF, ZSTR_KNOWN(ZEND_STR_FILE), &tmp);
    if (UNEXPECTED(EG(exception))) {
      RETURN_THROWS();
    }
  }

  if (!lineno_is_null) {
    ZVAL_LONG(&tmp, lineno);
    zend_update_property_num_checked(NULL, Z_OBJ_P(object), ZEND_EXCEPTION_LINE_OFF, ZSTR_KNOWN(ZEND_STR_LINE), &tmp);
    if (UNEXPECTED(EG(exception))) {
      RETURN_THROWS();
    }
  } else if (filename) {
    ZVAL_LONG(&tmp, 0);
    zend_update_property_num_checked(NULL, Z_OBJ_P(object), ZEND_EXCEPTION_LINE_OFF, ZSTR_KNOWN(ZEND_STR_LINE), &tmp);
    if (UNEXPECTED(EG(exception))) {
      RETURN_THROWS();
    }
  }
}
/* }}} */

#define GET_PROPERTY(object, id) \
  zend_read_property_ex(i_get_exception_base(Z_OBJ_P(object)), Z_OBJ_P(object), ZSTR_KNOWN(id), 0, &rv)
#define GET_PROPERTY_SILENT(object, id) \
  zend_read_property_ex(i_get_exception_base(Z_OBJ_P(object)), Z_OBJ_P(object), ZSTR_KNOWN(id), 1, &rv)

/* {{{ Get the file in which the exception occurred */
ZEND_METHOD(Exception, getFile)
{
  zval *prop, rv;

  ZEND_PARSE_PARAMETERS_NONE();

  prop = GET_PROPERTY(ZEND_THIS, ZEND_STR_FILE);
  RETURN_STR(zval_get_string(prop));
}
/* }}} */

/* {{{ Get the line in which the exception occurred */
ZEND_METHOD(Exception, getLine)
{
  zval *prop, rv;

  ZEND_PARSE_PARAMETERS_NONE();

  prop = GET_PROPERTY(ZEND_THIS, ZEND_STR_LINE);
  RETURN_LONG(zval_get_long(prop));
}
/* }}} */

/* {{{ Get the exception message */
ZEND_METHOD(Exception, getMessage)
{
  zval *prop, rv;

  ZEND_PARSE_PARAMETERS_NONE();

  prop = GET_PROPERTY(ZEND_THIS, ZEND_STR_MESSAGE);
  RETURN_STR(zval_get_string(prop));
}
/* }}} */

/* {{{ Get the exception code */
ZEND_METHOD(Exception, getCode)
{
  zval *prop, rv;

  ZEND_PARSE_PARAMETERS_NONE();

  prop = GET_PROPERTY(ZEND_THIS, ZEND_STR_CODE);
  ZVAL_DEREF(prop);
  ZVAL_COPY(return_value, prop);
}
/* }}} */

/* {{{ Get the stack trace for the location in which the exception occurred */
ZEND_METHOD(Exception, getTrace)
{
  zval *prop, rv;

  ZEND_PARSE_PARAMETERS_NONE();

  prop = GET_PROPERTY(ZEND_THIS, ZEND_STR_TRACE);
  ZVAL_DEREF(prop);
  ZVAL_COPY(return_value, prop);
}
/* }}} */

/* {{{ Get the exception severity */
ZEND_METHOD(ErrorException, getSeverity)
{
  zval *prop, rv;

  ZEND_PARSE_PARAMETERS_NONE();

  prop = GET_PROPERTY(ZEND_THIS, ZEND_STR_SEVERITY);
  ZVAL_DEREF(prop);
  ZVAL_COPY(return_value, prop);
}
/* }}} */

#define TRACE_APPEND_KEY(key) do {                                          \
    tmp = zend_hash_find(ht, key);                                      \
    if (tmp) {                                                          \
      if (UNEXPECTED(Z_TYPE_P(tmp) != IS_STRING)) {                   \
        zend_error(E_WARNING, "Value for %s is not a string",       \
          ZSTR_VAL(key));                                         \
        smart_str_appends(str, "[unknown]");                        \
      } else {                                                        \
        smart_str_append(str, Z_STR_P(tmp));                        \
      }                                                               \
    } \
  } while (0)

static void build_trace_args(zval *arg, smart_str *str) /* {{{ */
{
  /* the trivial way would be to do
   * convert_to_string(arg);
   * append it and kill the now tmp arg.
   * but that could cause some E_NOTICE and also damn long lines.
   */

  ZVAL_DEREF(arg);

  if (smart_str_append_zval(str, arg, EG(exception_string_param_max_len)) != SUCCESS) {
    switch (Z_TYPE_P(arg)) {
      case IS_RESOURCE:
        smart_str_appends(str, "Resource id #");
        smart_str_append_long(str, Z_RES_HANDLE_P(arg));
        break;
      case IS_ARRAY:
        smart_str_appends(str, "Array");
        break;
      case IS_OBJECT: {
        zend_string *class_name = Z_OBJ_HANDLER_P(arg, get_class_name)(Z_OBJ_P(arg));
        smart_str_appends(str, "Object(");
        /* cut off on NULL byte ... class@anonymous */
        smart_str_appends(str, ZSTR_VAL(class_name));
        smart_str_appends(str, ")");
        zend_string_release_ex(class_name, 0);
        break;
      }
    }
  }
}
/* }}} */

static void build_trace_args_list(zval *tmp, smart_str *str) /* {{{ */
{
  if (UNEXPECTED(Z_TYPE_P(tmp) != IS_ARRAY)) {
    /* only happens w/ reflection abuse (Zend/tests/bug63762.phpt) */
    zend_error(E_WARNING, "args element is not an array");
    return;
  }

  bool first = true;
  ZEND_HASH_FOREACH_STR_KEY_VAL(Z_ARRVAL_P(tmp), zend_string *name, zval *arg) {
    if (!first) {
      smart_str_appends(str, ", ");
    }
    first = false;
    if (name) {
      smart_str_append(str, name);
      smart_str_appends(str, ": ");
    }
    build_trace_args(arg, str);
  } ZEND_HASH_FOREACH_END();
}
/* }}} */

static void build_trace_string(smart_str *str, const HashTable *ht, uint32_t num) /* {{{ */
{
  zval *file, *tmp;

  smart_str_appendc(str, '#');
  smart_str_append_long(str, num);
  smart_str_appendc(str, ' ');

  file = zend_hash_find_known_hash(ht, ZSTR_KNOWN(ZEND_STR_FILE));
  if (file) {
    if (UNEXPECTED(Z_TYPE_P(file) != IS_STRING)) {
      zend_error(E_WARNING, "File name is not a string");
      smart_str_appends(str, "[unknown file]: ");
    } else{
      zend_long line = 0;
      tmp = zend_hash_find_known_hash(ht, ZSTR_KNOWN(ZEND_STR_LINE));
      if (tmp) {
        if (EXPECTED(Z_TYPE_P(tmp) == IS_LONG)) {
          line = Z_LVAL_P(tmp);
        } else {
          zend_error(E_WARNING, "Line is not an int");
        }
      }
      smart_str_append(str, Z_STR_P(file));
      smart_str_appendc(str, '(');
      smart_str_append_long(str, line);
      smart_str_appends(str, "): ");
    }
  } else {
    smart_str_appends(str, "[internal function]: ");
  }
  const zval *class_name = zend_hash_find(ht, ZSTR_KNOWN(ZEND_STR_CLASS));
  if (class_name) {
    if (UNEXPECTED(Z_TYPE_P(class_name) != IS_STRING)) {
      zend_error(E_WARNING, "Value for class is not a string");
      smart_str_appends(str, "[unknown]");
    } else {
      /* cut off on NULL byte ... class@anonymous */
      smart_str_appends(str, Z_STRVAL_P(class_name));
    }
  }
  TRACE_APPEND_KEY(ZSTR_KNOWN(ZEND_STR_TYPE));
  TRACE_APPEND_KEY(ZSTR_KNOWN(ZEND_STR_FUNCTION));
  smart_str_appendc(str, '(');
  tmp = zend_hash_find_known_hash(ht, ZSTR_KNOWN(ZEND_STR_ARGS));
  if (tmp) {
    build_trace_args_list(tmp, str);
  }
  smart_str_appends(str, ")\n");
}
/* }}} */

/* {{{ Gets the function arguments printed as a string from a backtrace frame. */
ZEND_API zend_string *zend_trace_function_args_to_string(const HashTable *frame) {
  smart_str str = {0};

  zval *tmp = zend_hash_find_known_hash(frame, ZSTR_KNOWN(ZEND_STR_ARGS));
  if (tmp) {
    build_trace_args_list(tmp, &str);
  }

  return smart_str_extract(&str);
}
/* }}} */

/* {{{ Gets the currently executing function's arguments as a string. Used by php_verror. */
ZEND_API zend_string *zend_trace_current_function_args_string(void) {
  zend_string *dynamic_params = NULL;
  /* get a backtrace to snarf function args */
  zval backtrace;
  zend_fetch_debug_backtrace(&backtrace, /* skip_last */ 0, /* options */ 0, /* limit */ 1);
  /* can fail esp if low memory condition */
  if (Z_TYPE(backtrace) == IS_ARRAY) {
    zval *first_frame = zend_hash_index_find(Z_ARRVAL(backtrace), 0);
    if (first_frame) {
      dynamic_params = zend_trace_function_args_to_string(Z_ARRVAL_P(first_frame));
    }
  }
  zval_ptr_dtor(&backtrace);
  return dynamic_params;
}
/* }}} */

ZEND_API zend_string *zend_trace_to_string(const HashTable *trace, bool include_main) {
  zend_ulong index;
  zval *frame;
  uint32_t num = 0;
  smart_str str = {0};

  ZEND_HASH_FOREACH_NUM_KEY_VAL(trace, index, frame) {
    if (UNEXPECTED(Z_TYPE_P(frame) != IS_ARRAY)) {
      zend_error(E_WARNING, "Expected array for frame " ZEND_ULONG_FMT, index);
      continue;
    }

    build_trace_string(&str, Z_ARRVAL_P(frame), num++);
  } ZEND_HASH_FOREACH_END();

  if (include_main) {
    smart_str_appendc(&str, '#');
    smart_str_append_long(&str, num);
    smart_str_appends(&str, " {main}");
  }

  smart_str_0(&str);
  return str.s ? str.s : ZSTR_EMPTY_ALLOC();
}

/* {{{ Obtain the backtrace for the exception as a string (instead of an array) */
ZEND_METHOD(Exception, getTraceAsString)
{

  ZEND_PARSE_PARAMETERS_NONE();

  zval *object = ZEND_THIS;
  zend_class_entry *base_ce = i_get_exception_base(Z_OBJ_P(object));
  zval rv;
  const zval *trace = zend_read_property_ex(base_ce, Z_OBJ_P(object), ZSTR_KNOWN(ZEND_STR_TRACE), 1, &rv);
  if (EG(exception)) {
    RETURN_THROWS();
  }

  ZVAL_DEREF(trace);
  /* Type should be guaranteed by property type. */
  ZEND_ASSERT(Z_TYPE_P(trace) == IS_ARRAY);
  RETURN_NEW_STR(zend_trace_to_string(Z_ARRVAL_P(trace), /* include_main */ true));
}
/* }}} */

/* {{{ Return previous Throwable or NULL. */
ZEND_METHOD(Exception, getPrevious)
{
  zval rv;

  ZEND_PARSE_PARAMETERS_NONE();

  ZVAL_COPY_DEREF(return_value, GET_PROPERTY_SILENT(ZEND_THIS, ZEND_STR_PREVIOUS));
} /* }}} */

/* {{{ Obtain the string representation of the Exception object */
ZEND_METHOD(Exception, __toString)
{
  zval trace, *exception;
  zend_class_entry *base_ce;
  zend_string *str;
  zval rv, tmp;

  ZEND_PARSE_PARAMETERS_NONE();

  str = ZSTR_EMPTY_ALLOC();

  exception = ZEND_THIS;
  base_ce = i_get_exception_base(Z_OBJ_P(exception));

  /* As getTraceAsString method is final we can grab it once */
  zend_function *getTraceAsString = zend_hash_str_find_ptr(&base_ce->function_table, ZEND_STRL("gettraceasstring"));
  ZEND_ASSERT(getTraceAsString && "Method getTraceAsString must exist");


  zend_fcall_info fci;
  fci.size = sizeof(fci);
  ZVAL_UNDEF(&fci.function_name);
  fci.retval = &trace;
  fci.param_count = 0;
  fci.params = NULL;
  fci.object = NULL;
  fci.named_params = NULL;

  zend_fcall_info_cache fcc;
  fcc.function_handler = getTraceAsString;
  fcc.called_scope = base_ce;
  fcc.closure = NULL;

  while (exception && Z_TYPE_P(exception) == IS_OBJECT && instanceof_function(Z_OBJCE_P(exception), zend_ce_throwable)) {
    zend_string *prev_str = str;
    zend_string *message = zval_get_string(GET_PROPERTY(exception, ZEND_STR_MESSAGE));
    zend_string *file = zval_get_string(GET_PROPERTY(exception, ZEND_STR_FILE));
    zend_long line = zval_get_long(GET_PROPERTY(exception, ZEND_STR_LINE));

    fcc.object = Z_OBJ_P(exception);
    fcc.calling_scope = Z_OBJCE_P(exception);
    zend_call_function(&fci, &fcc);

    if (Z_TYPE(trace) != IS_STRING) {
      zval_ptr_dtor(&trace);
      ZVAL_UNDEF(&trace);
    }

    if ((Z_OBJCE_P(exception) == zend_ce_type_error || Z_OBJCE_P(exception) == zend_ce_argument_count_error) && strstr(ZSTR_VAL(message), ", called in ")) {
      zend_string *real_message = zend_strpprintf_unchecked(0, "%S and defined", message);
      zend_string_release_ex(message, 0);
      message = real_message;
    }

    zend_string *tmp_trace = (Z_TYPE(trace) == IS_STRING && Z_STRLEN(trace))
      ? zend_string_copy(Z_STR(trace))
      : ZSTR_INIT_LITERAL("#0 {main}\n", false);

    zend_string *name = Z_OBJCE_P(exception)->name;

    if (ZSTR_LEN(message) > 0) {
      zval message_zv;
      ZVAL_STR(&message_zv, message);

      str = zend_strpprintf_unchecked(0, "%S: %S in %S:" ZEND_LONG_FMT "\nStack trace:\n%S%s%S",
        name, message, file, line,
        tmp_trace, ZSTR_LEN(prev_str) ? "\n\nNext " : "", prev_str);
    } else {
      str = zend_strpprintf_unchecked(0, "%S in %S:" ZEND_LONG_FMT "\nStack trace:\n%S%s%S",
        name, file, line,
        tmp_trace, ZSTR_LEN(prev_str) ? "\n\nNext " : "", prev_str);
    }
    zend_string_release_ex(tmp_trace, false);

    zend_string_release_ex(prev_str, 0);
    zend_string_release_ex(message, 0);
    zend_string_release_ex(file, 0);
    zval_ptr_dtor(&trace);

    Z_PROTECT_RECURSION_P(exception);
    exception = GET_PROPERTY(exception, ZEND_STR_PREVIOUS);
    ZVAL_DEREF(exception);
    if (Z_TYPE_P(exception) == IS_OBJECT && Z_IS_RECURSIVE_P(exception)) {
      break;
    }
  }

  exception = ZEND_THIS;
  /* Reset apply counts */
  zend_class_entry *previous_base_ce;
  while (Z_TYPE_P(exception) == IS_OBJECT && (previous_base_ce = i_get_exception_base(Z_OBJ_P(exception))) && instanceof_function(Z_OBJCE_P(exception), previous_base_ce)) {
    if (Z_IS_RECURSIVE_P(exception)) {
      Z_UNPROTECT_RECURSION_P(exception);
    } else {
      break;
    }
    exception = GET_PROPERTY(exception, ZEND_STR_PREVIOUS);
    ZVAL_DEREF(exception);
  }

  /* We store the result in the private property string so we can access
   * the result in uncaught exception handlers without memleaks. */
  ZVAL_STR(&tmp, str);
  zend_update_property_ex(base_ce, Z_OBJ_P(ZEND_THIS), ZSTR_KNOWN(ZEND_STR_STRING), &tmp);

  RETURN_STR(str);
}
/* }}} */

static void zend_init_exception_class_entry(zend_class_entry *ce) {
  ce->create_object = zend_default_exception_new;
  ce->default_object_handlers = &default_exception_handlers;
}

void zend_register_default_exception(void) /* {{{ */
{
  zend_ce_throwable = register_class_Throwable(zend_ce_stringable);
  zend_ce_throwable->interface_gets_implemented = zend_implement_throwable;

  memcpy(&default_exception_handlers, &std_object_handlers, sizeof(zend_object_handlers));
  default_exception_handlers.clone_obj = NULL;

  zend_ce_exception = register_class_Exception(zend_ce_throwable);
  zend_init_exception_class_entry(zend_ce_exception);

  zend_ce_error_exception = register_class_ErrorException(zend_ce_exception);
  zend_init_exception_class_entry(zend_ce_error_exception);

  zend_ce_error = register_class_Error(zend_ce_throwable);
  zend_init_exception_class_entry(zend_ce_error);

  zend_ce_compile_error = register_class_CompileError(zend_ce_error);
  zend_init_exception_class_entry(zend_ce_compile_error);

  zend_ce_parse_error = register_class_ParseError(zend_ce_compile_error);
  zend_init_exception_class_entry(zend_ce_parse_error);

  zend_ce_type_error = register_class_TypeError(zend_ce_error);
  zend_init_exception_class_entry(zend_ce_type_error);

  zend_ce_argument_count_error = register_class_ArgumentCountError(zend_ce_type_error);
  zend_init_exception_class_entry(zend_ce_argument_count_error);

  zend_ce_value_error = register_class_ValueError(zend_ce_error);
  zend_init_exception_class_entry(zend_ce_value_error);

  zend_ce_arithmetic_error = register_class_ArithmeticError(zend_ce_error);
  zend_init_exception_class_entry(zend_ce_arithmetic_error);

  zend_ce_division_by_zero_error = register_class_DivisionByZeroError(zend_ce_arithmetic_error);
  zend_init_exception_class_entry(zend_ce_division_by_zero_error);

  zend_ce_unhandled_match_error = register_class_UnhandledMatchError(zend_ce_error);
  zend_init_exception_class_entry(zend_ce_unhandled_match_error);

  zend_ce_request_parse_body_exception = register_class_RequestParseBodyException(zend_ce_exception);
  zend_init_exception_class_entry(zend_ce_request_parse_body_exception);

  INIT_CLASS_ENTRY(zend_ce_unwind_exit, "UnwindExit", NULL);

  INIT_CLASS_ENTRY(zend_ce_graceful_exit, "GracefulExit", NULL);
}
/* }}} */

static zend_object *zend_throw_exception_zstr(zend_class_entry *exception_ce, zend_string *message, zend_long code) /* {{{ */
{
  zval ex, tmp;

  if (!exception_ce) {
    exception_ce = zend_ce_exception;
  }

  ZEND_ASSERT(instanceof_function(exception_ce, zend_ce_throwable)
    && "Exceptions must implement Throwable");

  object_init_ex(&ex, exception_ce);

  if (message) {
    ZVAL_STR(&tmp, message);
    zend_update_property_ex(exception_ce, Z_OBJ(ex), ZSTR_KNOWN(ZEND_STR_MESSAGE), &tmp);
  }
  if (code) {
    ZVAL_LONG(&tmp, code);
    zend_update_property_ex(exception_ce, Z_OBJ(ex), ZSTR_KNOWN(ZEND_STR_CODE), &tmp);
  }

  zend_throw_exception_internal(Z_OBJ(ex));

  return Z_OBJ(ex);
}
/* }}} */

ZEND_API ZEND_COLD zend_object *zend_throw_exception(zend_class_entry *exception_ce, const char *message, zend_long code) /* {{{ */
{
  zend_string *msg_str = message ? zend_string_init(message, strlen(message), 0) : NULL;
  zend_object *ex = zend_throw_exception_zstr(exception_ce, msg_str, code);
  if (msg_str) {
    zend_string_release(msg_str);
  }
  return ex;
}
/* }}} */

ZEND_API ZEND_COLD zend_object *zend_throw_exception_ex(zend_class_entry *exception_ce, zend_long code, const char *format, ...) /* {{{ */
{
  va_list arg;
  zend_object *obj;

  va_start(arg, format);
  zend_string *msg_str = zend_vstrpprintf(0, format, arg);
  va_end(arg);
  obj = zend_throw_exception_zstr(exception_ce, msg_str, code);
  zend_string_release(msg_str);
  return obj;
}
/* }}} */

ZEND_API ZEND_COLD zend_object *zend_throw_error_exception(zend_class_entry *exception_ce, zend_string *message, zend_long code, int severity) /* {{{ */
{
  zend_object *obj = zend_throw_exception_zstr(exception_ce, message, code);
  if (exception_ce && instanceof_function(exception_ce, zend_ce_error_exception)) {
    zval tmp;
    ZVAL_LONG(&tmp, severity);
    zend_update_property_ex(zend_ce_error_exception, obj, ZSTR_KNOWN(ZEND_STR_SEVERITY), &tmp);
  }
  return obj;
}
/* }}} */

static void zend_error_va(int type, zend_string *file, uint32_t lineno, const char *format, ...) /* {{{ */
{
  va_list args;
  va_start(args, format);
  zend_string *message = zend_vstrpprintf(0, format, args);
  zend_observer_error_notify(type, file, lineno, message);
  zend_error_cb(type, file, lineno, message);
  zend_string_release(message);
  va_end(args);
}
/* }}} */

/* This function doesn't return if it uses E_ERROR */
ZEND_API ZEND_COLD zend_result zend_exception_error(zend_object *ex, int severity) /* {{{ */
{
  zval exception, rv;
  zend_class_entry *ce_exception;
  zend_result result = FAILURE;

  ZVAL_OBJ(&exception, ex);
  ce_exception = ex->ce;
  EG(exception) = NULL;

  zval_ptr_dtor(&EG(last_fatal_error_backtrace));
  ZVAL_UNDEF(&EG(last_fatal_error_backtrace));

  if (ce_exception == zend_ce_parse_error || ce_exception == zend_ce_compile_error) {
    zend_string *message = zval_get_string(GET_PROPERTY(&exception, ZEND_STR_MESSAGE));
    zend_string *file = zval_get_string(GET_PROPERTY_SILENT(&exception, ZEND_STR_FILE));
    zend_long line = zval_get_long(GET_PROPERTY_SILENT(&exception, ZEND_STR_LINE));
    int type = (ce_exception == zend_ce_parse_error ? E_PARSE : E_COMPILE_ERROR) | E_DONT_BAIL;

    zend_observer_error_notify(type, file, line, message);
    zend_error_cb(type, file, line, message);

    zend_string_release_ex(file, 0);
    zend_string_release_ex(message, 0);
  } else if (instanceof_function(ce_exception, zend_ce_throwable)) {
    zval tmp;
    zend_string *str, *file = NULL;
    zend_long line = 0;

    zend_call_known_instance_method_with_0_params(ex->ce->__tostring, ex, &tmp);
    if (!EG(exception)) {
      if (UNEXPECTED(Z_ISREF(tmp))) {
        zend_unwrap_reference(&tmp);
      }
      if (Z_TYPE(tmp) != IS_STRING) {
        zend_error(E_WARNING, "%s::__toString() must return a string", ZSTR_VAL(ce_exception->name));
      } else {
        zend_update_property_ex(i_get_exception_base(ex), ex, ZSTR_KNOWN(ZEND_STR_STRING), &tmp);
      }
    }
    zval_ptr_dtor(&tmp);

    if (EG(exception)) {
      zval zv;

      ZVAL_OBJ(&zv, EG(exception));
      /* do the best we can to inform about the inner exception */
      if (instanceof_function(ce_exception, zend_ce_exception) || instanceof_function(ce_exception, zend_ce_error)) {
        file = zval_get_string(GET_PROPERTY_SILENT(&zv, ZEND_STR_FILE));
        line = zval_get_long(GET_PROPERTY_SILENT(&zv, ZEND_STR_LINE));
      }

      zend_error_va(E_WARNING, (file && ZSTR_LEN(file) > 0) ? file : NULL, line,
        "Uncaught %s in exception handling during call to %s::__toString()",
        ZSTR_VAL(Z_OBJCE(zv)->name), ZSTR_VAL(ce_exception->name));

      if (file) {
        zend_string_release_ex(file, 0);
      }
    }

    str = zval_get_string(GET_PROPERTY_SILENT(&exception, ZEND_STR_STRING));
    file = zval_get_string(GET_PROPERTY_SILENT(&exception, ZEND_STR_FILE));
    line = zval_get_long(GET_PROPERTY_SILENT(&exception, ZEND_STR_LINE));

    zend_error_va(severity | E_DONT_BAIL,
      (file && ZSTR_LEN(file) > 0) ? file : NULL, line,
      "Uncaught %S\n  thrown", str);

    zend_string_release_ex(str, 0);
    zend_string_release_ex(file, 0);
  } else if (ce_exception == &zend_ce_unwind_exit || ce_exception == &zend_ce_graceful_exit) {
    /* We successfully unwound, nothing more to do.
     * We still return FAILURE in this case, as further execution should still be aborted. */
  } else {
    zend_error(severity, "Uncaught exception %s", ZSTR_VAL(ce_exception->name));
  }

  OBJ_RELEASE(ex);
  return result;
}
/* }}} */

ZEND_NORETURN void zend_exception_uncaught_error(const char *format, ...) {
  va_list va;
  va_start(va, format);
  zend_string *prefix = zend_vstrpprintf(0, format, va);
  va_end(va);

  ZEND_ASSERT(EG(exception));
  zval exception_zv;
  ZVAL_OBJ_COPY(&exception_zv, EG(exception));
  zend_clear_exception();

  zend_string *exception_str = zval_get_string(&exception_zv);
  zend_error_noreturn(E_ERROR,
    "%s: Uncaught %s", ZSTR_VAL(prefix), ZSTR_VAL(exception_str));
}

ZEND_API ZEND_COLD void zend_throw_exception_object(zval *exception) /* {{{ */
{
  if (exception == NULL || Z_TYPE_P(exception) != IS_OBJECT) {
    zend_error_noreturn(E_CORE_ERROR, "Need to supply an object when throwing an exception");
  }

  zend_class_entry *exception_ce = Z_OBJCE_P(exception);

  if (!exception_ce || !instanceof_function(exception_ce, zend_ce_throwable)) {
    zend_throw_error(NULL, "Cannot throw objects that do not implement Throwable");
    zval_ptr_dtor(exception);
    return;
  }

  zend_throw_exception_internal(Z_OBJ_P(exception));
}
/* }}} */

ZEND_API ZEND_COLD zend_object *zend_create_unwind_exit(void)
{
  return zend_objects_new(&zend_ce_unwind_exit);
}

ZEND_API ZEND_COLD zend_object *zend_create_graceful_exit(void)
{
  return zend_objects_new(&zend_ce_graceful_exit);
}

ZEND_API ZEND_COLD void zend_throw_unwind_exit(void)
{
  ZEND_ASSERT(!EG(exception));
  EG(exception) = zend_create_unwind_exit();
  EG(opline_before_exception) = EG(current_execute_data)->opline;
  EG(current_execute_data)->opline = EG(exception_op);
}

ZEND_API ZEND_COLD void zend_throw_graceful_exit(void)
{
  ZEND_ASSERT(!EG(exception));
  EG(exception) = zend_create_graceful_exit();
  EG(opline_before_exception) = EG(current_execute_data)->opline;
  EG(current_execute_data)->opline = EG(exception_op);
}

ZEND_API bool zend_is_unwind_exit(const zend_object *ex)
{
  return ex->ce == &zend_ce_unwind_exit;
}

ZEND_API bool zend_is_graceful_exit(const zend_object *ex)
{
  return ex->ce == &zend_ce_graceful_exit;
}

Coverage Report

Created: 2026-06-02 06:37