js/xpconnect/loader/nsImportModule.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef nsImportModule_h
   8 #define nsImportModule_h
   9
  10 #include "mozilla/Assertions.h"
  11 #include "mozilla/Attributes.h"
  12
  13 #include "nsCOMPtr.h"
  14 #include "mozilla/RefPtr.h"
  15
  16 namespace mozilla {
  17 namespace loader {
  18
  19 nsresult ImportESModule(const char* aURI, const char* aExportName,
  20                         const nsIID& aIID, void** aResult, bool aInfallible);
  21
  22 }  // namespace loader
  23 }  // namespace mozilla
  24
  25 class MOZ_STACK_CLASS nsImportESModule final : public nsCOMPtr_helper {
  26  public:
  27   nsImportESModule(const char* aURI, const char* aExportName,
  28                    nsresult* aErrorPtr, bool aInfallible)
  29       : mURI(aURI),
  30         mExportName(aExportName),
  31         mErrorPtr(aErrorPtr),
  32         mInfallible(aInfallible) {
  33     MOZ_ASSERT_IF(mErrorPtr, !mInfallible);
  34   }
  35
  36   virtual nsresult NS_FASTCALL operator()(const nsIID& aIID,
  37                                           void** aResult) const override {
  38     nsresult rv = ::mozilla::loader::ImportESModule(mURI, mExportName, aIID,
  39                                                     aResult, mInfallible);
  40     if (mErrorPtr) {
  41       *mErrorPtr = rv;
  42     }
  43     return rv;
  44   }
  45
  46  private:
  47   const char* mURI;
  48   const char* mExportName;
  49   nsresult* mErrorPtr;
  50   bool mInfallible;
  51 };
  52
  53 /**
  54  * Usage with exported name:
  55  *
  56  * Foo.sys.mjs:
  57  *
  58  *   export function foo(bar) {
  59  *     return bar.toString();
  60  *   }
  61  *
  62  * mozIFoo.idl:
  63  *
  64  *   interface mozIFoo : nsISupports {
  65  *     AString foo(double meh);
  66  *   }
  67  *
  68  * Thing.cpp:
  69  *
  70  *   nsCOMPtr<mozIFoo> foo = do_ImportESModule(
  71  *     "resource://meh/Foo.sys.mjs");
  72  *
  73  *   MOZ_TRY(foo->Foo(42));
  74  *
  75  * Usage with a single named object:
  76  *
  77  * Foo.sys.mjs:
  78  *
  79  *   export var Foo = {
  80  *     function foo(bar) {
  81  *       return bar.toString();
  82  *     }
  83  *   };
  84  *
  85  * Thing.cpp:
  86  *
  87  *   nsCOMPtr<mozIFoo> foo = do_ImportESModule(
  88  *       "resource:://meh/Foo.sys.mjs", "Foo");
  89  */
  90
  91 template <size_t N>
  92 inline nsImportESModule do_ImportESModule(const char (&aURI)[N]) {
  93   return {aURI, nullptr, nullptr, /* infallible */ true};
  94 }
  95
  96 template <size_t N>
  97 inline nsImportESModule do_ImportESModule(const char (&aURI)[N],
  98                                           const mozilla::fallible_t&) {
  99   return {aURI, nullptr, nullptr, /* infallible */ false};
 100 }
 101
 102 template <size_t N>
 103 inline nsImportESModule do_ImportESModule(const char (&aURI)[N],
 104                                           nsresult* aRv) {
 105   return {aURI, nullptr, aRv, /* infallible */ false};
 106 }
 107
 108 template <size_t N, size_t N2>
 109 inline nsImportESModule do_ImportESModule(const char (&aURI)[N],
 110                                           const char (&aExportName)[N2]) {
 111   return {aURI, aExportName, nullptr, /* infallible */ true};
 112 }
 113
 114 template <size_t N, size_t N2>
 115 inline nsImportESModule do_ImportESModule(const char (&aURI)[N],
 116                                           const char (&aExportName)[N2],
 117                                           const mozilla::fallible_t&) {
 118   return {aURI, aExportName, nullptr, /* infallible */ false};
 119 }
 120
 121 template <size_t N, size_t N2>
 122 inline nsImportESModule do_ImportESModule(const char (&aURI)[N],
 123                                           const char (&aExportName)[N2],
 124                                           nsresult* aRv) {
 125   return {aURI, aExportName, aRv, /* infallible */ false};
 126 }
 127
 128 #endif  // defined nsImportModule_h