summaryrefslogtreecommitdiffstats
path: root/dom/base/nsJSUtils.cpp
blob: 2e6e345a32c62c4a4efd9c2618b6f085d7feb657 (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
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
/* -*- 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 "jsapi.h"
#include "jsfriendapi.h"
#include "nsIScriptContext.h"
#include "nsIScriptGlobalObject.h"
#include "nsIXPConnect.h"
#include "nsCOMPtr.h"
#include "nsIScriptSecurityManager.h"
#include "nsPIDOMWindow.h"
#include "GeckoProfiler.h"
#include "nsJSPrincipals.h"
#include "xpcpublic.h"
#include "nsContentUtils.h"
#include "nsGlobalWindow.h"

#include "mozilla/dom/BindingUtils.h"
#include "mozilla/dom/Date.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/ScriptSettings.h"

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;
  }

  aFilename.Assign(filename.get());
  return true;
}

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;
  }

  aFilename.Assign(NS_ConvertUTF8toUTF16(filename.get()));
  return true;
}

nsIScriptGlobalObject *
nsJSUtils::GetStaticScriptGlobal(JSObject* aObj)
{
  if (!aObj)
    return nullptr;
  return xpc::WindowGlobalOrNull(aObj);
}

nsIScriptContext *
nsJSUtils::GetStaticScriptContext(JSObject* aObj)
{
  nsIScriptGlobalObject *nativeGlobal = GetStaticScriptGlobal(aObj);
  if (!nativeGlobal)
    return nullptr;

  return nativeGlobal->GetScriptContext();
}

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

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

nsresult
nsJSUtils::CompileFunction(AutoJSAPI& jsapi,
                           JS::AutoObjectVector& 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::GetEnterCompartmentDepth(cx) > 0);
  MOZ_ASSERT_IF(aScopeChain.length() != 0,
                js::IsObjectInContextCompartment(aScopeChain[0], cx));
  MOZ_ASSERT_IF(aOptions.versionSet, aOptions.version != JSVERSION_UNKNOWN);

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

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

nsresult
nsJSUtils::EvaluateString(JSContext* aCx,
                          const nsAString& aScript,
                          JS::Handle<JSObject*> aEvaluationGlobal,
                          JS::CompileOptions& aCompileOptions,
                          const EvaluateOptions& aEvaluateOptions,
                          JS::MutableHandle<JS::Value> aRetValue)
{
  const nsPromiseFlatString& flatScript = PromiseFlatString(aScript);
  JS::SourceBufferHolder srcBuf(flatScript.get(), aScript.Length(),
                                JS::SourceBufferHolder::NoOwnership);
  return EvaluateString(aCx, srcBuf, aEvaluationGlobal, aCompileOptions,
                        aEvaluateOptions, aRetValue, nullptr);
}

nsresult
nsJSUtils::EvaluateString(JSContext* aCx,
                          JS::SourceBufferHolder& aSrcBuf,
                          JS::Handle<JSObject*> aEvaluationGlobal,
                          JS::CompileOptions& aCompileOptions,
                          const EvaluateOptions& aEvaluateOptions,
                          JS::MutableHandle<JS::Value> aRetValue,
                          void **aOffThreadToken)
{
  PROFILER_LABEL("nsJSUtils", "EvaluateString",
    js::ProfileEntry::Category::JS);

  MOZ_ASSERT_IF(aCompileOptions.versionSet,
                aCompileOptions.version != JSVERSION_UNKNOWN);
  MOZ_ASSERT_IF(aEvaluateOptions.coerceToString, !aCompileOptions.noScriptRval);
  MOZ_ASSERT(aCx == nsContentUtils::GetCurrentJSContext());
  MOZ_ASSERT(aSrcBuf.get());
  MOZ_ASSERT(js::GetGlobalForObjectCrossCompartment(aEvaluationGlobal) ==
             aEvaluationGlobal);
  MOZ_ASSERT_IF(aOffThreadToken, aCompileOptions.noScriptRval);
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(nsContentUtils::IsInMicroTask());

  // Unfortunately, the JS engine actually compiles scripts with a return value
  // in a different, less efficient way.  Furthermore, it can't JIT them in many
  // cases.  So we need to be explicitly told whether the caller cares about the
  // return value.  Callers can do this by calling the other overload of
  // EvaluateString() which calls this function with
  // aCompileOptions.noScriptRval set to true.
  aRetValue.setUndefined();

  nsresult rv = NS_OK;

  NS_ENSURE_TRUE(xpc::Scriptability::Get(aEvaluationGlobal).Allowed(), NS_OK);

  bool ok = true;
  // Scope the JSAutoCompartment so that we can later wrap the return value
  // into the caller's cx.
  {
    JSAutoCompartment ac(aCx, aEvaluationGlobal);

    // Now make sure to wrap the scope chain into the right compartment.
    JS::AutoObjectVector scopeChain(aCx);
    if (!scopeChain.reserve(aEvaluateOptions.scopeChain.length())) {
      return NS_ERROR_OUT_OF_MEMORY;
    }

    for (size_t i = 0; i < aEvaluateOptions.scopeChain.length(); ++i) {
      JS::ExposeObjectToActiveJS(aEvaluateOptions.scopeChain[i]);
      scopeChain.infallibleAppend(aEvaluateOptions.scopeChain[i]);
      if (!JS_WrapObject(aCx, scopeChain[i])) {
        ok = false;
        break;
      }
    }

    if (ok && aOffThreadToken) {
      JS::Rooted<JSScript*>
        script(aCx, JS::FinishOffThreadScript(aCx, *aOffThreadToken));
      *aOffThreadToken = nullptr; // Mark the token as having been finished.
      if (script) {
        ok = JS_ExecuteScript(aCx, scopeChain, script);
      } else {
        ok = false;
      }
    } else if (ok) {
      ok = JS::Evaluate(aCx, scopeChain, aCompileOptions, aSrcBuf, aRetValue);
    }

    if (ok && aEvaluateOptions.coerceToString && !aRetValue.isUndefined()) {
      JS::Rooted<JS::Value> value(aCx, aRetValue);
      JSString* str = JS::ToString(aCx, value);
      ok = !!str;
      aRetValue.set(ok ? JS::StringValue(str) : JS::UndefinedValue());
    }
  }

  if (!ok) {
    if (JS_IsExceptionPending(aCx)) {
      rv = NS_SUCCESS_DOM_SCRIPT_EVALUATION_THREW;
    } else {
      rv = NS_SUCCESS_DOM_SCRIPT_EVALUATION_THREW_UNCATCHABLE;
    }

    if (!aCompileOptions.noScriptRval) {
      aRetValue.setUndefined();
    }
  }

  // Wrap the return value into whatever compartment aCx was in.
  if (ok && !aCompileOptions.noScriptRval) {
    if (!JS_WrapValue(aCx, aRetValue)) {
      return NS_ERROR_OUT_OF_MEMORY;
    }
  }
  return rv;
}

nsresult
nsJSUtils::EvaluateString(JSContext* aCx,
                          JS::SourceBufferHolder& aSrcBuf,
                          JS::Handle<JSObject*> aEvaluationGlobal,
                          JS::CompileOptions& aCompileOptions,
                          const EvaluateOptions& aEvaluateOptions,
                          JS::MutableHandle<JS::Value> aRetValue)
{
  return EvaluateString(aCx, aSrcBuf, aEvaluationGlobal, aCompileOptions,
                        aEvaluateOptions, aRetValue, nullptr);
}

nsresult
nsJSUtils::EvaluateString(JSContext* aCx,
                          const nsAString& aScript,
                          JS::Handle<JSObject*> aEvaluationGlobal,
                          JS::CompileOptions& aCompileOptions)
{
  EvaluateOptions options(aCx);
  aCompileOptions.setNoScriptRval(true);
  JS::RootedValue unused(aCx);
  return EvaluateString(aCx, aScript, aEvaluationGlobal, aCompileOptions,
                        options, &unused);
}

nsresult
nsJSUtils::EvaluateString(JSContext* aCx,
                          JS::SourceBufferHolder& aSrcBuf,
                          JS::Handle<JSObject*> aEvaluationGlobal,
                          JS::CompileOptions& aCompileOptions,
                          void **aOffThreadToken)
{
  EvaluateOptions options(aCx);
  aCompileOptions.setNoScriptRval(true);
  JS::RootedValue unused(aCx);
  return EvaluateString(aCx, aSrcBuf, aEvaluationGlobal, aCompileOptions,
                        options, &unused, aOffThreadToken);
}

nsresult
nsJSUtils::CompileModule(JSContext* aCx,
                       JS::SourceBufferHolder& aSrcBuf,
                       JS::Handle<JSObject*> aEvaluationGlobal,
                       JS::CompileOptions &aCompileOptions,
                       JS::MutableHandle<JSObject*> aModule)
{
  PROFILER_LABEL("nsJSUtils", "CompileModule",
    js::ProfileEntry::Category::JS);

  MOZ_ASSERT_IF(aCompileOptions.versionSet,
                aCompileOptions.version != JSVERSION_UNKNOWN);
  MOZ_ASSERT(aCx == nsContentUtils::GetCurrentJSContext());
  MOZ_ASSERT(aSrcBuf.get());
  MOZ_ASSERT(js::GetGlobalForObjectCrossCompartment(aEvaluationGlobal) ==
             aEvaluationGlobal);
  MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx) == aEvaluationGlobal);
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(nsContentUtils::IsInMicroTask());

  NS_ENSURE_TRUE(xpc::Scriptability::Get(aEvaluationGlobal).Allowed(), NS_OK);

  if (!JS::CompileModule(aCx, aCompileOptions, aSrcBuf, aModule)) {
    return NS_ERROR_FAILURE;
  }

  return NS_OK;
}

nsresult
nsJSUtils::ModuleInstantiate(JSContext* aCx, JS::Handle<JSObject*> aModule)
{
  PROFILER_LABEL("nsJSUtils", "ModuleInstantiate",
    js::ProfileEntry::Category::JS);

  MOZ_ASSERT(aCx == nsContentUtils::GetCurrentJSContext());
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(CycleCollectedJSContext::Get() &&
             CycleCollectedJSContext::Get()->MicroTaskLevel());

  NS_ENSURE_TRUE(xpc::Scriptability::Get(aModule).Allowed(), NS_OK);

  if (!JS::ModuleInstantiate(aCx, aModule)) {
    return NS_ERROR_FAILURE;
  }

  return NS_OK;
}

nsresult
nsJSUtils::ModuleEvaluate(JSContext* aCx, JS::Handle<JSObject*> aModule)
{
  PROFILER_LABEL("nsJSUtils", "ModuleEvaluate",
    js::ProfileEntry::Category::JS);

  MOZ_ASSERT(aCx == nsContentUtils::GetCurrentJSContext());
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(nsContentUtils::IsInMicroTask());

  NS_ENSURE_TRUE(xpc::Scriptability::Get(aModule).Allowed(), NS_OK);

  if (!JS::ModuleEvaluate(aCx, aModule)) {
    return NS_ERROR_FAILURE;
  }

  return NS_OK;
}

/* static */
bool
nsJSUtils::GetScopeChainForElement(JSContext* aCx,
                                   mozilla::dom::Element* aElement,
                                   JS::AutoObjectVector& aScopeChain)
{
  for (nsINode* cur = aElement; cur; cur = cur->GetScopeChainParent()) {
    JS::RootedValue val(aCx);
    if (!GetOrCreateDOMReflector(aCx, cur, &val)) {
      return false;
    }

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

  return true;
}

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

//
// nsDOMJSUtils.h
//

bool nsAutoJSString::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;
}