1// Copyright (C) 2016 The Qt Company Ltd.
2// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
3
4#include <QString>
5#include <qv4context_p.h>
6#include <qv4object_p.h>
7#include <qv4objectproto_p.h>
8#include <private/qv4mm_p.h>
9#include <qv4argumentsobject_p.h>
10#include "qv4function_p.h"
11#include "qv4stackframe_p.h"
12#include "qv4symbol_p.h"
13
14using namespace QV4;
15
16DEFINE_MANAGED_VTABLE(ExecutionContext);
17DEFINE_MANAGED_VTABLE(CallContext);
18
19Heap::CallContext *ExecutionContext::newBlockContext(CppStackFrame *frame, int blockIndex)
20{
21 Function *function = frame->v4Function;
22
23 Heap::InternalClass *ic = function->executableCompilationUnit()->runtimeBlocks.at(i: blockIndex);
24 uint nLocals = ic->size;
25 size_t requiredMemory = sizeof(CallContext::Data) - sizeof(Value) + sizeof(Value) * nLocals;
26
27 ExecutionEngine *v4 = function->internalClass->engine;
28 Heap::CallContext *c = v4->memoryManager->allocManaged<CallContext>(size: requiredMemory, ic);
29 c->init();
30 c->type = Heap::ExecutionContext::Type_BlockContext;
31
32 Heap::ExecutionContext *outer = static_cast<Heap::ExecutionContext *>(frame->context()->m());
33 c->outer.set(e: v4, newVal: outer);
34 if (frame->isJSTypesFrame()) {
35 c->function.set(e: v4, newVal: static_cast<Heap::JavaScriptFunctionObject *>(
36 Value::fromStaticValue(
37 staticValue: static_cast<JSTypesStackFrame *>(frame)->jsFrame->function).m()));
38 } else {
39 c->function.set(e: v4, newVal: nullptr);
40 }
41
42 c->locals.size = nLocals;
43 c->locals.alloc = nLocals;
44
45 c->setupLocalTemporalDeadZone(function->executableCompilationUnit()->unitData()->blockAt(idx: blockIndex));
46
47 return c;
48}
49
50Heap::CallContext *ExecutionContext::cloneBlockContext(ExecutionEngine *engine,
51 Heap::CallContext *callContext)
52{
53 uint nLocals = callContext->locals.alloc;
54 size_t requiredMemory = sizeof(CallContext::Data) - sizeof(Value) + sizeof(Value) * nLocals;
55
56 Heap::CallContext *c = engine->memoryManager->allocManaged<CallContext>(
57 size: requiredMemory, ic: callContext->internalClass);
58 memcpy(dest: c, src: callContext, n: requiredMemory);
59
60 return c;
61}
62
63Heap::CallContext *ExecutionContext::newCallContext(JSTypesStackFrame *frame)
64{
65 Function *function = frame->v4Function;
66 Heap::ExecutionContext *outer = static_cast<Heap::ExecutionContext *>(frame->context()->m());
67
68 uint nFormals = qMax(a: static_cast<uint>(frame->argc()), b: function->nFormals);
69 uint localsAndFormals = function->compiledFunction->nLocals + nFormals;
70 size_t requiredMemory = sizeof(CallContext::Data) - sizeof(Value) + sizeof(Value) * (localsAndFormals);
71
72 ExecutionEngine *v4 = outer->internalClass->engine;
73 Heap::CallContext *c = v4->memoryManager->allocManaged<CallContext>(size: requiredMemory, ic: function->internalClass);
74 c->init();
75
76 c->outer.set(e: v4, newVal: outer);
77 c->function.set(e: v4, newVal: static_cast<Heap::JavaScriptFunctionObject *>(
78 Value::fromStaticValue(staticValue: frame->jsFrame->function).m()));
79
80 const CompiledData::Function *compiledFunction = function->compiledFunction;
81 uint nLocals = compiledFunction->nLocals;
82 c->locals.size = nLocals;
83 c->locals.alloc = localsAndFormals;
84 // memory allocated from the JS heap is 0 initialized, so check if empty is 0
85 Q_ASSERT(Value::undefinedValue().asReturnedValue() == 0);
86
87 c->setupLocalTemporalDeadZone(compiledFunction);
88
89 Value *args = c->locals.values + nLocals;
90 ::memcpy(dest: args, src: frame->argv(), n: frame->argc() * sizeof(Value));
91 c->nArgs = frame->argc();
92 for (uint i = frame->argc(); i < function->nFormals; ++i)
93 args[i] = Encode::undefined();
94
95 return c;
96}
97
98Heap::ExecutionContext *ExecutionContext::newWithContext(Heap::Object *with) const
99{
100 Heap::ExecutionContext *c = engine()->memoryManager->alloc<ExecutionContext>(args: Heap::ExecutionContext::Type_WithContext);
101 c->outer.set(e: engine(), newVal: d());
102 c->activation.set(e: engine(), newVal: with);
103
104 return c;
105}
106
107Heap::ExecutionContext *ExecutionContext::newCatchContext(CppStackFrame *frame, int blockIndex, Heap::String *exceptionVarName)
108{
109 Scope scope(frame->context());
110 ScopedString name(scope, exceptionVarName);
111 ScopedValue val(scope, scope.engine->catchException(trace: nullptr));
112 ScopedContext ctx(scope, newBlockContext(frame, blockIndex));
113 ctx->setProperty(name, value: val);
114 return ctx->d();
115}
116
117void ExecutionContext::createMutableBinding(String *name, bool deletable)
118{
119 Scope scope(this);
120
121 // find the right context to create the binding on
122 ScopedObject activation(scope);
123 ScopedContext ctx(scope, this);
124 while (ctx) {
125 switch (ctx->d()->type) {
126 case Heap::ExecutionContext::Type_CallContext:
127 if (!activation) {
128 Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx->d());
129 if (!c->activation)
130 c->activation.set(e: scope.engine, newVal: scope.engine->newObject());
131 activation = c->activation;
132 }
133 break;
134 case Heap::ExecutionContext::Type_QmlContext: {
135 // this is ugly, as it overrides the inner callcontext, but has to stay as long
136 // as bindings still get their own callcontext
137 activation = ctx->d()->activation;
138 break;
139 }
140 case Heap::ExecutionContext::Type_GlobalContext: {
141 Q_ASSERT(scope.engine->globalObject->d() == ctx->d()->activation);
142 if (!activation)
143 activation = ctx->d()->activation;
144 break;
145 }
146 case Heap::ExecutionContext::Type_BlockContext:
147 // never create activation records on block contexts
148 default:
149 break;
150 }
151 ctx = ctx->d()->outer;
152 }
153
154 PropertyKey id = name->toPropertyKey();
155 if (activation->getOwnProperty(id) != Attr_Invalid)
156 return;
157 ScopedProperty desc(scope);
158 PropertyAttributes attrs(Attr_Data);
159 attrs.setConfigurable(deletable);
160 if (!activation->defineOwnProperty(id, p: desc, attrs))
161 scope.engine->throwTypeError();
162}
163
164static bool unscopable(ExecutionEngine *engine, Heap::Object *withObject, PropertyKey id)
165{
166 if (!withObject)
167 return false;
168 Scope scope(engine);
169 ScopedObject w(scope, withObject);
170 ScopedObject o(scope, w->get(name: scope.engine->symbol_unscopables()));
171 if (o) {
172 ScopedValue blocked(scope, o->get(id));
173 return blocked->toBoolean();
174 }
175 return false;
176}
177
178bool ExecutionContext::deleteProperty(String *name)
179{
180 PropertyKey id = name->toPropertyKey();
181
182 Heap::ExecutionContext *ctx = d();
183 ExecutionEngine *engine = ctx->internalClass->engine;
184
185 for (; ctx; ctx = ctx->outer) {
186 switch (ctx->type) {
187 case Heap::ExecutionContext::Type_BlockContext:
188 case Heap::ExecutionContext::Type_CallContext: {
189 Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx);
190 uint index = c->internalClass->indexOfValueOrGetter(id);
191 if (index < UINT_MAX)
192 // ### throw in strict mode?
193 return false;
194 Q_FALLTHROUGH();
195 }
196 case Heap::ExecutionContext::Type_WithContext: {
197 if (ctx->activation) {
198 Scope scope(this);
199 ScopedObject object(scope, ctx->activation);
200 if (object && object->hasProperty(id)) {
201 bool u = ::unscopable(engine, withObject: ctx->activation, id);
202 if (engine->hasException)
203 return false;
204 if (u)
205 break;
206 return object->deleteProperty(id);
207 }
208 }
209 break;
210 }
211 case Heap::ExecutionContext::Type_GlobalContext: {
212 if (ctx->activation) {
213 Scope scope(this);
214 ScopedObject object(scope, ctx->activation);
215 if (object && object->hasProperty(id))
216 return object->deleteProperty(id);
217 }
218 break;
219 }
220 case Heap::ExecutionContext::Type_QmlContext:
221 // can't delete properties on qml objects
222 break;
223 }
224 }
225
226 return !engine->currentStackFrame->v4Function->isStrict();
227}
228
229ExecutionContext::Error ExecutionContext::setProperty(String *name, const Value &value)
230{
231 PropertyKey id = name->toPropertyKey();
232
233 Heap::ExecutionContext *ctx = d();
234 QV4::ExecutionEngine *engine = ctx->internalClass->engine;
235
236 for (; ctx; ctx = ctx->outer) {
237 switch (ctx->type) {
238 case Heap::ExecutionContext::Type_WithContext: {
239 Scope scope(engine);
240 ScopedObject w(scope, ctx->activation);
241 if (w->hasProperty(id)) {
242 bool u = ::unscopable(engine, withObject: ctx->activation, id);
243 if (engine->hasException)
244 return TypeError;
245 if (u)
246 break;
247 if (!w->put(name, v: value))
248 return TypeError;
249 return NoError;
250 }
251 break;
252 }
253 case Heap::ExecutionContext::Type_BlockContext:
254 case Heap::ExecutionContext::Type_CallContext: {
255 Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx);
256 uint index = c->internalClass->indexOfValueOrGetter(id);
257 if (index < UINT_MAX) {
258 static_cast<Heap::CallContext *>(c)->locals.set(e: engine, index, v: value);
259 return NoError;
260 }
261 }
262 Q_FALLTHROUGH();
263 case Heap::ExecutionContext::Type_GlobalContext:
264 if (ctx->activation) {
265 auto member = ctx->activation->internalClass->findValueOrSetter(id);
266 if (member.index < UINT_MAX) {
267 Scope scope(engine);
268 ScopedObject a(scope, ctx->activation);
269 if (!a->putValue(memberIndex: member.index, attrs: member.attrs, value))
270 return TypeError;
271 return NoError;
272 }
273 }
274 break;
275 case Heap::ExecutionContext::Type_QmlContext: {
276 Scope scope(engine);
277 ScopedObject activation(scope, ctx->activation);
278 if (!activation->put(name, v: value))
279 return TypeError;
280 return NoError;
281 }
282 }
283
284 }
285
286 return RangeError;
287}
288
289ReturnedValue ExecutionContext::getProperty(String *name)
290{
291 PropertyKey id = name->toPropertyKey();
292
293 Heap::ExecutionContext *ctx = d();
294 QV4::ExecutionEngine *engine = ctx->internalClass->engine;
295
296 for (; ctx; ctx = ctx->outer) {
297 switch (ctx->type) {
298 case Heap::ExecutionContext::Type_BlockContext:
299 case Heap::ExecutionContext::Type_CallContext: {
300 Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx);
301
302 const uint index = c->internalClass->indexOfValueOrGetter(id);
303 if (index < c->locals.alloc)
304 return c->locals[index].asReturnedValue();
305
306 // TODO: We should look up the module imports here, but those are part of the CU:
307 // imports[index - c->locals.size];
308 // See QTBUG-118478
309
310 Q_FALLTHROUGH();
311 }
312 case Heap::ExecutionContext::Type_WithContext:
313 if (ctx->activation) {
314 Scope scope(this);
315 ScopedObject activation(scope, ctx->activation);
316 if (activation->hasProperty(id)) {
317 bool u = ::unscopable(engine, withObject: ctx->activation, id);
318 if (engine->hasException)
319 return false;
320 if (u)
321 break;
322 return activation->get(id);
323 }
324 }
325 break;
326 case Heap::ExecutionContext::Type_GlobalContext:
327 case Heap::ExecutionContext::Type_QmlContext: {
328 if (ctx->activation) {
329 Scope scope(this);
330 ScopedObject activation(scope, ctx->activation);
331 bool hasProperty = false;
332 ReturnedValue v = activation->get(id, receiver: nullptr, hasProperty: &hasProperty);
333 if (hasProperty)
334 return v;
335 }
336 break;
337 }
338 }
339 }
340 return engine->throwReferenceError(value: *name);
341}
342
343ReturnedValue ExecutionContext::getPropertyAndBase(String *name, Value *base)
344{
345 base->setM(nullptr);
346 PropertyKey id = name->toPropertyKey();
347
348 Heap::ExecutionContext *ctx = d();
349 QV4::ExecutionEngine *engine = ctx->internalClass->engine;
350
351 for (; ctx; ctx = ctx->outer) {
352 switch (ctx->type) {
353 case Heap::ExecutionContext::Type_BlockContext:
354 case Heap::ExecutionContext::Type_CallContext: {
355 Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx);
356
357 const uint index = c->internalClass->indexOfValueOrGetter(id);
358 if (index < c->locals.alloc)
359 return c->locals[index].asReturnedValue();
360
361 // TODO: We should look up the module imports here, but those are part of the CU:
362 // imports[index - c->locals.size];
363 // See QTBUG-118478
364
365 Q_FALLTHROUGH();
366 }
367 case Heap::ExecutionContext::Type_GlobalContext: {
368 if (ctx->activation) {
369 Scope scope(this);
370 ScopedObject activation(scope, ctx->activation);
371 bool hasProperty = false;
372 ReturnedValue v = activation->get(name, hasProperty: &hasProperty);
373 if (hasProperty)
374 return v;
375 }
376 break;
377 }
378 case Heap::ExecutionContext::Type_WithContext:
379 if (ctx->activation) {
380 Scope scope(this);
381 ScopedObject activation(scope, ctx->activation);
382 if (activation->hasProperty(id)) {
383 bool u = ::unscopable(engine, withObject: ctx->activation, id);
384 if (engine->hasException)
385 return false;
386 if (u)
387 break;
388 base->setM(activation->d());
389 return activation->get(id);
390 }
391 }
392 break;
393 case Heap::ExecutionContext::Type_QmlContext: {
394 Scope scope(this);
395 ScopedObject o(scope, ctx->activation);
396 bool hasProperty = false;
397 ReturnedValue v = o->get(id, receiver: nullptr, hasProperty: &hasProperty);
398 if (hasProperty) {
399 base->setM(o->d());
400 return v;
401 }
402 break;
403 }
404 }
405 }
406 return engine->throwReferenceError(value: *name);
407}
408
409void Heap::CallContext::setArg(uint index, Value v)
410{
411 locals.set(e: internalClass->engine, index: locals.size + index, v);
412}
413

source code of qtdeclarative/src/qml/jsruntime/qv4context.cpp