summaryrefslogtreecommitdiffstats
path: root/dom/base/nsJSUtils.cpp
blob: 86fe04583c34bd84f7239c3515c9f335d84f48a2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/**
 * This is not a generated file. It contains common utility functions
 * invoked from the JavaScript code generated from IDL interfaces.
 * The goal of the utility functions is to cut down on the size of
 * the generated code itself.
 */

#include "nsJSUtils.h"

#include <utility>
#include "MainThreadUtils.h"
#include "js/ComparisonOperators.h"
#include "js/CompilationAndEvaluation.h"
#include "js/CompileOptions.h"
#include "js/Date.h"
#include "js/GCVector.h"
#include "js/HeapAPI.h"
#include "js/Modules.h"
#include "js/RootingAPI.h"
#include "js/SourceText.h"
#include "js/TypeDecls.h"
#include "jsfriendapi.h"
#include "mozilla/CycleCollectedJSContext.h"
#include "mozilla/dom/BindingUtils.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/ScriptSettings.h"
#include "mozilla/fallible.h"
#include "mozilla/ProfilerLabels.h"
#include "nsContentUtils.h"
#include "nsDebug.h"
#include "nsGlobalWindowInner.h"
#include "nsINode.h"
#include "nsString.h"
#include "nsTPromiseFlatString.h"
#include "nscore.h"
#include "prenv.h"

#if !defined(DEBUG) && !defined(MOZ_ENABLE_JS_DUMP)
#  include "mozilla/StaticPrefs_browser.h"
#endif

using namespace mozilla;
using namespace mozilla::dom;

bool nsJSUtils::GetCallingLocation(JSContext* aContext, nsACString& aFilename,
                                   uint32_t* aLineno, uint32_t* aColumn) {
  JS::AutoFilename filename;
  if (!JS::DescribeScriptedCaller(aContext, &filename, aLineno, aColumn)) {
    return false;
  }

  return aFilename.Assign(filename.get(), fallible);
}

bool nsJSUtils::GetCallingLocation(JSContext* aContext, nsAString& aFilename,
                                   uint32_t* aLineno, uint32_t* aColumn) {
  JS::AutoFilename filename;
  if (!JS::DescribeScriptedCaller(aContext, &filename, aLineno, aColumn)) {
    return false;
  }

  return aFilename.Assign(NS_ConvertUTF8toUTF16(filename.get()), fallible);
}

uint64_t nsJSUtils::GetCurrentlyRunningCodeInnerWindowID(JSContext* aContext) {
  if (!aContext) return 0;

  nsGlobalWindowInner* win = xpc::CurrentWindowOrNull(aContext);
  return win ? win->WindowID() : 0;
}

nsresult nsJSUtils::UpdateFunctionDebugMetadata(
    AutoJSAPI& jsapi, JS::Handle<JSObject*> aFun, JS::CompileOptions& aOptions,
    JS::Handle<JSString*> aElementAttributeName,
    JS::Handle<JS::Value> aPrivateValue) {
  JSContext* cx = jsapi.cx();

  JS::Rooted<JSFunction*> fun(cx, JS_GetObjectFunction(aFun));
  if (!fun) {
    return NS_ERROR_FAILURE;
  }

  JS::Rooted<JSScript*> script(cx, JS_GetFunctionScript(cx, fun));
  if (!script) {
    return NS_OK;
  }

  JS::InstantiateOptions instantiateOptions(aOptions);
  if (!JS::UpdateDebugMetadata(cx, script, instantiateOptions, aPrivateValue,
                               aElementAttributeName, nullptr, nullptr)) {
    return NS_ERROR_FAILURE;
  }
  return NS_OK;
}

nsresult nsJSUtils::CompileFunction(AutoJSAPI& jsapi,
                                    JS::HandleVector<JSObject*> aScopeChain,
                                    JS::CompileOptions& aOptions,
                                    const nsACString& aName, uint32_t aArgCount,
                                    const char** aArgArray,
                                    const nsAString& aBody,
                                    JSObject** aFunctionObject) {
  JSContext* cx = jsapi.cx();
  MOZ_ASSERT(js::GetContextRealm(cx));
  MOZ_ASSERT_IF(aScopeChain.length() != 0,
                js::IsObjectInContextCompartment(aScopeChain[0], cx));

  // Do the junk Gecko is supposed to do before calling into JSAPI.
  for (size_t i = 0; i < aScopeChain.length(); ++i) {
    JS::ExposeObjectToActiveJS(aScopeChain[i]);
  }

  // Compile.
  const nsPromiseFlatString& flatBody = PromiseFlatString(aBody);

  JS::SourceText<char16_t> source;
  if (!source.init(cx, flatBody.get(), flatBody.Length(),
                   JS::SourceOwnership::Borrowed)) {
    return NS_ERROR_FAILURE;
  }

  JS::Rooted<JSFunction*> fun(
      cx, JS::CompileFunction(cx, aScopeChain, aOptions,
                              PromiseFlatCString(aName).get(), aArgCount,
                              aArgArray, source));
  if (!fun) {
    return NS_ERROR_FAILURE;
  }

  *aFunctionObject = JS_GetFunctionObject(fun);
  return NS_OK;
}

/* static */
bool nsJSUtils::IsScriptable(JS::Handle<JSObject*> aEvaluationGlobal) {
  return xpc::Scriptability::AllowedIfExists(aEvaluationGlobal);
}

static bool AddScopeChainItem(JSContext* aCx, nsINode* aNode,
                              JS::MutableHandleVector<JSObject*> aScopeChain) {
  JS::Rooted<JS::Value> val(aCx);
  if (!GetOrCreateDOMReflector(aCx, aNode, &val)) {
    return false;
  }

  if (!aScopeChain.append(&val.toObject())) {
    return false;
  }

  return true;
}

/* static */
bool nsJSUtils::GetScopeChainForElement(
    JSContext* aCx, Element* aElement,
    JS::MutableHandleVector<JSObject*> aScopeChain) {
  for (nsINode* cur = aElement; cur; cur = cur->GetScopeChainParent()) {
    if (!AddScopeChainItem(aCx, cur, aScopeChain)) {
      return false;
    }
  }

  return true;
}

/* static */
void nsJSUtils::ResetTimeZone() { JS::ResetTimeZone(); }

/* static */
bool nsJSUtils::DumpEnabled() {
#ifdef FUZZING
  static bool mozFuzzDebug = !!PR_GetEnv("MOZ_FUZZ_DEBUG");
  return mozFuzzDebug;
#endif

#if defined(DEBUG) || defined(MOZ_ENABLE_JS_DUMP)
  return true;
#else
  return StaticPrefs::browser_dom_window_dump_enabled();
#endif
}

JSObject* nsJSUtils::MoveBufferAsUint8Array(JSContext* aCx, size_t aSize,
                                            UniquePtr<uint8_t>& aBuffer) {
  JS::Rooted<JSObject*> arrayBuffer(
      aCx, JS::NewArrayBufferWithContents(aCx, aSize, aBuffer.get()));
  if (!arrayBuffer) {
    return nullptr;
  }

  // Now the ArrayBuffer owns the buffer, so let's release our ownership
  (void)aBuffer.release();

  return JS_NewUint8ArrayWithBuffer(aCx, arrayBuffer, 0,
                                    static_cast<int64_t>(aSize));
}

//
// nsDOMJSUtils.h
//

template <typename T>
bool nsTAutoJSString<T>::init(const JS::Value& v) {
  // Note: it's okay to use danger::GetJSContext here instead of AutoJSAPI,
  // because the init() call below is careful not to run script (for instance,
  // it only calls JS::ToString for non-object values).
  JSContext* cx = danger::GetJSContext();
  if (!init(cx, v)) {
    JS_ClearPendingException(cx);
    return false;
  }
  return true;
}

template bool nsTAutoJSString<char16_t>::init(const JS::Value&);
template bool nsTAutoJSString<char>::init(const JS::Value&);