hphp/runtime/vm/type-alias.h

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-2014 Facebook, Inc. (http://www.facebook.com)     |
   6    +----------------------------------------------------------------------+
   7    | This source file is subject to version 3.01 of the PHP license,      |
   8    | that is bundled with this package in the file LICENSE, and is        |
   9    | available through the world-wide-web at the following url:           |
  10    | http://www.php.net/license/3_01.txt                                  |
  11    | If you did not receive a copy of the PHP license and are unable to   |
  12    | obtain it through the world-wide-web, please send a note to          |
  13    | license@php.net so we can mail you a copy immediately.               |
  14    +----------------------------------------------------------------------+
  15 */
  16
  17 #ifndef incl_HPHP_TYPE_ALIAS_H_
  18 #define incl_HPHP_TYPE_ALIAS_H_
  19
  20 #include "hphp/runtime/base/types.h"
  21 #include "hphp/runtime/base/attr.h"
  22 #include "hphp/runtime/base/datatype.h"
  23
  24 namespace HPHP {
  25 ///////////////////////////////////////////////////////////////////////////////
  26
  27 struct Class;
  28 struct StringData;
  29
  30 ///////////////////////////////////////////////////////////////////////////////
  31
  32 /*
  33  * This is the runtime representation of a type alias.  Type aliases are only
  34  * allowed when HipHop extensions are enabled.
  35  *
  36  * The m_kind field is KindOfObject whenever the type alias is basically just a
  37  * name.  At runtime we still might resolve this name to another type alias,
  38  * becoming a type alias for KindOfArray or something in that request.
  39  *
  40  * For the per-request struct, see TypeAliasReq below.
  41  */
  42 struct TypeAlias {
  43   LowStringPtr name;
  44   LowStringPtr value;
  45   DataType     kind;
  46   bool         any;       // overrides `kind' for mixed aliases
  47   bool         nullable;  // null is allowed; for ?Foo aliases
  48   Attr         attrs;
  49
  50   template<class SerDe> void serde(SerDe& sd) {
  51     sd(name)
  52       (value)
  53       (kind)
  54       (any)
  55       (nullable)
  56       (attrs)
  57       ;
  58   }
  59 };
  60
  61
  62 ///////////////////////////////////////////////////////////////////////////////
  63
  64 /*
  65  * In a given request, a defined type alias is turned into a TypeAliasReq
  66  * struct.  This contains the information needed to validate parameter type
  67  * hints for a type alias at runtime.
  68  */
  69 struct TypeAliasReq {
  70
  71   /////////////////////////////////////////////////////////////////////////////
  72   // Static constructors.
  73
  74   static TypeAliasReq Invalid();
  75   static TypeAliasReq From(const TypeAlias& alias);
  76   static TypeAliasReq From(TypeAliasReq req, const TypeAlias& alias);
  77
  78
  79   /////////////////////////////////////////////////////////////////////////////
  80   // Comparison.
  81
  82   bool same(const TypeAliasReq& req) const;
  83   bool compat(const TypeAlias& alias) const;
  84
  85
  86   /////////////////////////////////////////////////////////////////////////////
  87   // Data members.
  88
  89   // The alised type.
  90   DataType kind{KindOfUninit};
  91   // Overrides `kind' if the alias is invalid (e.g., for a nonexistent class).
  92   bool invalid{false};
  93   // Overrides `kind' for "HH\\mixed".
  94   bool any{false};
  95   // For option types, like ?Foo.
  96   bool nullable{false};
  97   // Aliased Class; nullptr if kind != KindOfObject.
  98   LowClassPtr klass{nullptr};
  99   // Needed for error messages; nullptr if not defined.
 100   LowStringPtr name{nullptr};
 101 };
 102
 103 bool operator==(const TypeAliasReq& l, const TypeAliasReq& r);
 104 bool operator!=(const TypeAliasReq& l, const TypeAliasReq& r);
 105
 106 ///////////////////////////////////////////////////////////////////////////////
 107 }
 108
 109 #define incl_HPHP_TYPE_ALIAS_INL_H_
 110 #include "hphp/runtime/vm/type-alias-inl.h"
 111 #undef incl_HPHP_TYPE_ALIAS_INL_H_
 112
 113 #endif