hphp/hhbbc/type-structure.h

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-present 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 #pragma once
  17
  18 #include "hphp/hhbbc/context.h"
  19 #include "hphp/hhbbc/misc.h"
  20 #include "hphp/hhbbc/type-system.h"
  21
  22 namespace HPHP::HHBBC {
  23
  24 //////////////////////////////////////////////////////////////////////
  25
  26 struct CollectedInfo;
  27 struct IIndex;
  28 struct ISS;
  29
  30 namespace php {
  31   struct Class;
  32   struct Const;
  33   struct TypeAlias;
  34 }
  35
  36 //////////////////////////////////////////////////////////////////////
  37
  38 /*
  39  * Result of resolve_type_structure
  40  */
  41 struct TypeStructureResolution {
  42   Type type; // Best known type of the *resolved* type-structure. If
  43              // the type-structure can be statically pre-resolved,
  44              // this will be a static array.
  45   bool mightFail; // Whether the resolution can possibly fail
  46   bool contextSensitive{false}; // If the resolution involved context
  47                                 // sensitive information. If so, only
  48                                 // the declaring class can safely use
  49                                 // the resolved type.
  50
  51   // If the resolution results in a static array with no possibility
  52   // of failure, return it.
  53   SArray sarray() const {
  54     if (mightFail) return nullptr;
  55     auto const v = tv(type);
  56     if (!v) return nullptr;
  57     assertx(tvIsDict(*v));
  58     assertx(val(*v).parr->isStatic());
  59     return val(*v).parr;
  60   }
  61
  62   TypeStructureResolution& operator|=(const TypeStructureResolution& o) {
  63     type |= o.type;
  64     mightFail |= o.mightFail;
  65     contextSensitive |= o.contextSensitive;
  66     return *this;
  67   }
  68 };
  69
  70 /*
  71  * Attempt to resolve the given type-structure, either "anonymous",
  72  * from a class constant, or from a type-alias.
  73  */
  74 TypeStructureResolution resolve_type_structure(const ISS&, SArray);
  75 TypeStructureResolution resolve_type_structure(const IIndex&,
  76                                                const php::Const& cns,
  77                                                const php::Class& thiz);
  78 TypeStructureResolution resolve_type_structure(const IIndex&,
  79                                                const CollectedInfo*,
  80                                                const php::TypeAlias&);
  81
  82 //////////////////////////////////////////////////////////////////////
  83
  84 /*
  85  * If the type-structure represents a class or an unresolved type,
  86  * retrieve the associated name of the class.
  87  */
  88 SString type_structure_name(SArray);
  89
  90 //////////////////////////////////////////////////////////////////////
  91
  92 }