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1 // Copyright 2016 PDFium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
6 
7 #include "fxjs/cfxjse_context.h"
8 
9 #include <utility>
10 
11 #include "fxjs/cfxjse_class.h"
12 #include "fxjs/cfxjse_value.h"
13 #include "third_party/base/ptr_util.h"
14 
15 namespace {
16 
17 const char szCompatibleModeScript[] =
18     "(function(global, list) {\n"
19     "  'use strict';\n"
20     "  var objname;\n"
21     "  for (objname in list) {\n"
22     "    var globalobj = global[objname];\n"
23     "    if (globalobj) {\n"
24     "      list[objname].forEach(function(name) {\n"
25     "        if (!globalobj[name]) {\n"
26     "          Object.defineProperty(globalobj, name, {\n"
27     "            writable: true,\n"
28     "            enumerable: false,\n"
29     "            value: (function(obj) {\n"
30     "              if (arguments.length === 0) {\n"
31     "                throw new TypeError('missing argument 0 when calling "
32     "                    function ' + objname + '.' + name);\n"
33     "              }\n"
34     "              return globalobj.prototype[name].apply(obj, "
35     "                  Array.prototype.slice.call(arguments, 1));\n"
36     "            })\n"
37     "          });\n"
38     "        }\n"
39     "      });\n"
40     "    }\n"
41     "  }\n"
42     "}(this, {String: ['substr', 'toUpperCase']}));";
43 
44 wchar_t g_FXJSETagString[] = L"FXJSE_HostObject";
45 
CreateReturnValue(v8::Isolate * pIsolate,v8::TryCatch & trycatch)46 v8::Local<v8::Object> CreateReturnValue(v8::Isolate* pIsolate,
47                                         v8::TryCatch& trycatch) {
48   v8::Local<v8::Object> hReturnValue = v8::Object::New(pIsolate);
49   if (trycatch.HasCaught()) {
50     v8::Local<v8::Value> hException = trycatch.Exception();
51     v8::Local<v8::Message> hMessage = trycatch.Message();
52     if (hException->IsObject()) {
53       v8::Local<v8::Value> hValue;
54       hValue = hException.As<v8::Object>()->Get(
55           v8::String::NewFromUtf8(pIsolate, "name"));
56       if (hValue->IsString() || hValue->IsStringObject())
57         hReturnValue->Set(0, hValue);
58       else
59         hReturnValue->Set(0, v8::String::NewFromUtf8(pIsolate, "Error"));
60 
61       hValue = hException.As<v8::Object>()->Get(
62           v8::String::NewFromUtf8(pIsolate, "message"));
63       if (hValue->IsString() || hValue->IsStringObject())
64         hReturnValue->Set(1, hValue);
65       else
66         hReturnValue->Set(1, hMessage->Get());
67     } else {
68       hReturnValue->Set(0, v8::String::NewFromUtf8(pIsolate, "Error"));
69       hReturnValue->Set(1, hMessage->Get());
70     }
71     hReturnValue->Set(2, hException);
72     hReturnValue->Set(3, v8::Integer::New(pIsolate, hMessage->GetLineNumber()));
73     hReturnValue->Set(4, hMessage->GetSourceLine());
74     v8::Maybe<int32_t> maybe_int =
75         hMessage->GetStartColumn(pIsolate->GetCurrentContext());
76     hReturnValue->Set(5, v8::Integer::New(pIsolate, maybe_int.FromMaybe(0)));
77     maybe_int = hMessage->GetEndColumn(pIsolate->GetCurrentContext());
78     hReturnValue->Set(6, v8::Integer::New(pIsolate, maybe_int.FromMaybe(0)));
79   }
80   return hReturnValue;
81 }
82 
GetGlobalObjectFromContext(v8::Local<v8::Context> hContext)83 v8::Local<v8::Object> GetGlobalObjectFromContext(
84     v8::Local<v8::Context> hContext) {
85   return hContext->Global()->GetPrototype().As<v8::Object>();
86 }
87 
88 }  // namespace
89 
90 // Note, not in the anonymous namespace due to the friend call
91 // in cfxjse_context.h
92 // TODO(dsinclair): Remove the friending, use public methods.
93 class CFXJSE_ScopeUtil_IsolateHandleContext {
94  public:
CFXJSE_ScopeUtil_IsolateHandleContext(CFXJSE_Context * pContext)95   explicit CFXJSE_ScopeUtil_IsolateHandleContext(CFXJSE_Context* pContext)
96       : m_context(pContext),
97         m_parent(pContext->m_pIsolate),
98         m_cscope(v8::Local<v8::Context>::New(pContext->m_pIsolate,
99                                              pContext->m_hContext)) {}
GetIsolate()100   v8::Isolate* GetIsolate() { return m_context->m_pIsolate; }
GetLocalContext()101   v8::Local<v8::Context> GetLocalContext() {
102     return v8::Local<v8::Context>::New(m_context->m_pIsolate,
103                                        m_context->m_hContext);
104   }
105 
106  private:
107   CFXJSE_ScopeUtil_IsolateHandleContext(
108       const CFXJSE_ScopeUtil_IsolateHandleContext&) = delete;
109   void operator=(const CFXJSE_ScopeUtil_IsolateHandleContext&) = delete;
110   void* operator new(size_t size) = delete;
111   void operator delete(void*, size_t) = delete;
112 
113   UnownedPtr<CFXJSE_Context> m_context;
114   CFXJSE_ScopeUtil_IsolateHandle m_parent;
115   v8::Context::Scope m_cscope;
116 };
117 
FXJSE_UpdateObjectBinding(v8::Local<v8::Object> & hObject,CFXJSE_HostObject * lpNewBinding)118 void FXJSE_UpdateObjectBinding(v8::Local<v8::Object>& hObject,
119                                CFXJSE_HostObject* lpNewBinding) {
120   ASSERT(!hObject.IsEmpty());
121   ASSERT(hObject->InternalFieldCount() == 2);
122   hObject->SetAlignedPointerInInternalField(0, g_FXJSETagString);
123   hObject->SetAlignedPointerInInternalField(1, lpNewBinding);
124 }
125 
FXJSE_RetrieveObjectBinding(v8::Local<v8::Object> hJSObject,CFXJSE_Class * lpClass)126 CFXJSE_HostObject* FXJSE_RetrieveObjectBinding(v8::Local<v8::Object> hJSObject,
127                                                CFXJSE_Class* lpClass) {
128   ASSERT(!hJSObject.IsEmpty());
129   if (!hJSObject->IsObject())
130     return nullptr;
131 
132   v8::Local<v8::Object> hObject = hJSObject;
133   if (hObject->InternalFieldCount() != 2) {
134     v8::Local<v8::Value> hProtoObject = hObject->GetPrototype();
135     if (hProtoObject.IsEmpty() || !hProtoObject->IsObject())
136       return nullptr;
137 
138     hObject = hProtoObject.As<v8::Object>();
139     if (hObject->InternalFieldCount() != 2)
140       return nullptr;
141   }
142   if (hObject->GetAlignedPointerFromInternalField(0) != g_FXJSETagString)
143     return nullptr;
144   if (lpClass) {
145     v8::Local<v8::FunctionTemplate> hClass =
146         v8::Local<v8::FunctionTemplate>::New(
147             lpClass->GetContext()->GetIsolate(), lpClass->GetTemplate());
148     if (!hClass->HasInstance(hObject))
149       return nullptr;
150   }
151   return static_cast<CFXJSE_HostObject*>(
152       hObject->GetAlignedPointerFromInternalField(1));
153 }
154 
155 // static
Create(v8::Isolate * pIsolate,const FXJSE_CLASS_DESCRIPTOR * pGlobalClass,CFXJSE_HostObject * pGlobalObject)156 std::unique_ptr<CFXJSE_Context> CFXJSE_Context::Create(
157     v8::Isolate* pIsolate,
158     const FXJSE_CLASS_DESCRIPTOR* pGlobalClass,
159     CFXJSE_HostObject* pGlobalObject) {
160   CFXJSE_ScopeUtil_IsolateHandle scope(pIsolate);
161   auto pContext = pdfium::MakeUnique<CFXJSE_Context>(pIsolate);
162   v8::Local<v8::ObjectTemplate> hObjectTemplate;
163   if (pGlobalClass) {
164     CFXJSE_Class* pGlobalClassObj =
165         CFXJSE_Class::Create(pContext.get(), pGlobalClass, true);
166     ASSERT(pGlobalClassObj);
167     v8::Local<v8::FunctionTemplate> hFunctionTemplate =
168         v8::Local<v8::FunctionTemplate>::New(pIsolate,
169                                              pGlobalClassObj->m_hTemplate);
170     hObjectTemplate = hFunctionTemplate->InstanceTemplate();
171   } else {
172     hObjectTemplate = v8::ObjectTemplate::New(pIsolate);
173     hObjectTemplate->SetInternalFieldCount(2);
174   }
175 
176   hObjectTemplate->Set(
177       v8::Symbol::GetToStringTag(pIsolate),
178       v8::String::NewFromUtf8(pIsolate, "global", v8::NewStringType::kNormal)
179           .ToLocalChecked());
180   v8::Local<v8::Context> hNewContext =
181       v8::Context::New(pIsolate, nullptr, hObjectTemplate);
182   v8::Local<v8::Context> hRootContext = v8::Local<v8::Context>::New(
183       pIsolate, CFXJSE_RuntimeData::Get(pIsolate)->m_hRootContext);
184   hNewContext->SetSecurityToken(hRootContext->GetSecurityToken());
185   v8::Local<v8::Object> hGlobalObject = GetGlobalObjectFromContext(hNewContext);
186   FXJSE_UpdateObjectBinding(hGlobalObject, pGlobalObject);
187   pContext->m_hContext.Reset(pIsolate, hNewContext);
188   return pContext;
189 }
190 
CFXJSE_Context(v8::Isolate * pIsolate)191 CFXJSE_Context::CFXJSE_Context(v8::Isolate* pIsolate) : m_pIsolate(pIsolate) {}
192 
~CFXJSE_Context()193 CFXJSE_Context::~CFXJSE_Context() {}
194 
GetGlobalObject()195 std::unique_ptr<CFXJSE_Value> CFXJSE_Context::GetGlobalObject() {
196   auto pValue = pdfium::MakeUnique<CFXJSE_Value>(m_pIsolate);
197   CFXJSE_ScopeUtil_IsolateHandleContext scope(this);
198   v8::Local<v8::Context> hContext =
199       v8::Local<v8::Context>::New(m_pIsolate, m_hContext);
200   v8::Local<v8::Object> hGlobalObject = GetGlobalObjectFromContext(hContext);
201   pValue->ForceSetValue(hGlobalObject);
202   return pValue;
203 }
204 
GetContext()205 v8::Local<v8::Context> CFXJSE_Context::GetContext() {
206   return v8::Local<v8::Context>::New(m_pIsolate, m_hContext);
207 }
208 
AddClass(std::unique_ptr<CFXJSE_Class> pClass)209 void CFXJSE_Context::AddClass(std::unique_ptr<CFXJSE_Class> pClass) {
210   m_rgClasses.push_back(std::move(pClass));
211 }
212 
GetClassByName(const ByteStringView & szName) const213 CFXJSE_Class* CFXJSE_Context::GetClassByName(
214     const ByteStringView& szName) const {
215   auto pClass =
216       std::find_if(m_rgClasses.begin(), m_rgClasses.end(),
217                    [szName](const std::unique_ptr<CFXJSE_Class>& item) {
218                      return szName == item->m_szClassName;
219                    });
220   return pClass != m_rgClasses.end() ? pClass->get() : nullptr;
221 }
222 
EnableCompatibleMode()223 void CFXJSE_Context::EnableCompatibleMode() {
224   ExecuteScript(szCompatibleModeScript, nullptr, nullptr);
225 }
226 
ExecuteScript(const char * szScript,CFXJSE_Value * lpRetValue,CFXJSE_Value * lpNewThisObject)227 bool CFXJSE_Context::ExecuteScript(const char* szScript,
228                                    CFXJSE_Value* lpRetValue,
229                                    CFXJSE_Value* lpNewThisObject) {
230   CFXJSE_ScopeUtil_IsolateHandleContext scope(this);
231   v8::TryCatch trycatch(m_pIsolate);
232   v8::Local<v8::String> hScriptString =
233       v8::String::NewFromUtf8(m_pIsolate, szScript);
234   if (!lpNewThisObject) {
235     v8::Local<v8::Script> hScript = v8::Script::Compile(hScriptString);
236     if (!trycatch.HasCaught()) {
237       v8::Local<v8::Value> hValue = hScript->Run();
238       if (!trycatch.HasCaught()) {
239         if (lpRetValue)
240           lpRetValue->m_hValue.Reset(m_pIsolate, hValue);
241         return true;
242       }
243     }
244     if (lpRetValue) {
245       lpRetValue->m_hValue.Reset(m_pIsolate,
246                                  CreateReturnValue(m_pIsolate, trycatch));
247     }
248     return false;
249   }
250 
251   v8::Local<v8::Value> hNewThis =
252       v8::Local<v8::Value>::New(m_pIsolate, lpNewThisObject->m_hValue);
253   ASSERT(!hNewThis.IsEmpty());
254   v8::Local<v8::Script> hWrapper = v8::Script::Compile(v8::String::NewFromUtf8(
255       m_pIsolate, "(function () { return eval(arguments[0]); })"));
256   v8::Local<v8::Value> hWrapperValue = hWrapper->Run();
257   ASSERT(hWrapperValue->IsFunction());
258   v8::Local<v8::Function> hWrapperFn = hWrapperValue.As<v8::Function>();
259   if (!trycatch.HasCaught()) {
260     v8::Local<v8::Value> rgArgs[] = {hScriptString};
261     v8::Local<v8::Value> hValue =
262         hWrapperFn->Call(hNewThis.As<v8::Object>(), 1, rgArgs);
263     if (!trycatch.HasCaught()) {
264       if (lpRetValue)
265         lpRetValue->m_hValue.Reset(m_pIsolate, hValue);
266       return true;
267     }
268   }
269   if (lpRetValue) {
270     lpRetValue->m_hValue.Reset(m_pIsolate,
271                                CreateReturnValue(m_pIsolate, trycatch));
272   }
273   return false;
274 }
275