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1 // Copyright 2014 the V8 project 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 #include "src/compiler/js-inlining.h"
6 
7 #include "src/ast/ast.h"
8 #include "src/codegen/compiler.h"
9 #include "src/codegen/optimized-compilation-info.h"
10 #include "src/codegen/tick-counter.h"
11 #include "src/compiler/access-builder.h"
12 #include "src/compiler/all-nodes.h"
13 #include "src/compiler/bytecode-graph-builder.h"
14 #include "src/compiler/common-operator.h"
15 #include "src/compiler/compiler-source-position-table.h"
16 #include "src/compiler/graph-reducer.h"
17 #include "src/compiler/js-heap-broker.h"
18 #include "src/compiler/js-operator.h"
19 #include "src/compiler/node-matchers.h"
20 #include "src/compiler/node-properties.h"
21 #include "src/compiler/operator-properties.h"
22 #include "src/compiler/simplified-operator.h"
23 #include "src/execution/isolate-inl.h"
24 #include "src/objects/feedback-cell-inl.h"
25 #include "src/parsing/parse-info.h"
26 
27 #if V8_ENABLE_WEBASSEMBLY
28 #include "src/compiler/wasm-compiler.h"
29 #endif  // V8_ENABLE_WEBASSEMBLY
30 
31 namespace v8 {
32 namespace internal {
33 namespace compiler {
34 
35 namespace {
36 // This is just to avoid some corner cases, especially since we allow recursive
37 // inlining.
38 static const int kMaxDepthForInlining = 50;
39 }  // namespace
40 
41 #define TRACE(x)                     \
42   do {                               \
43     if (FLAG_trace_turbo_inlining) { \
44       StdoutStream() << x << "\n";   \
45     }                                \
46   } while (false)
47 
48 // Provides convenience accessors for the common layout of nodes having either
49 // the {JSCall} or the {JSConstruct} operator.
50 class JSCallAccessor {
51  public:
JSCallAccessor(Node * call)52   explicit JSCallAccessor(Node* call) : call_(call) {
53     DCHECK(call->opcode() == IrOpcode::kJSCall ||
54            call->opcode() == IrOpcode::kJSConstruct);
55   }
56 
target() const57   Node* target() const {
58     return call_->InputAt(JSCallOrConstructNode::TargetIndex());
59   }
60 
receiver() const61   Node* receiver() const {
62     return JSCallNode{call_}.receiver();
63   }
64 
new_target() const65   Node* new_target() const { return JSConstructNode{call_}.new_target(); }
66 
frame_state() const67   FrameState frame_state() const {
68     return FrameState{NodeProperties::GetFrameStateInput(call_)};
69   }
70 
argument_count() const71   int argument_count() const {
72     return (call_->opcode() == IrOpcode::kJSCall)
73                ? JSCallNode{call_}.ArgumentCount()
74                : JSConstructNode{call_}.ArgumentCount();
75   }
76 
frequency() const77   CallFrequency const& frequency() const {
78     return (call_->opcode() == IrOpcode::kJSCall)
79                ? JSCallNode{call_}.Parameters().frequency()
80                : JSConstructNode{call_}.Parameters().frequency();
81   }
82 
83  private:
84   Node* call_;
85 };
86 
87 #if V8_ENABLE_WEBASSEMBLY
InlineJSWasmCall(Node * call,Node * new_target,Node * context,Node * frame_state,StartNode start,Node * end,Node * exception_target,const NodeVector & uncaught_subcalls)88 Reduction JSInliner::InlineJSWasmCall(Node* call, Node* new_target,
89                                       Node* context, Node* frame_state,
90                                       StartNode start, Node* end,
91                                       Node* exception_target,
92                                       const NodeVector& uncaught_subcalls) {
93   JSWasmCallNode n(call);
94   return InlineCall(
95       call, new_target, context, frame_state, start, end, exception_target,
96       uncaught_subcalls,
97       static_cast<int>(n.Parameters().signature()->parameter_count()));
98 }
99 #endif  // V8_ENABLE_WEBASSEMBLY
100 
InlineCall(Node * call,Node * new_target,Node * context,Node * frame_state,StartNode start,Node * end,Node * exception_target,const NodeVector & uncaught_subcalls,int argument_count)101 Reduction JSInliner::InlineCall(Node* call, Node* new_target, Node* context,
102                                 Node* frame_state, StartNode start, Node* end,
103                                 Node* exception_target,
104                                 const NodeVector& uncaught_subcalls,
105                                 int argument_count) {
106   DCHECK_IMPLIES(IrOpcode::IsInlineeOpcode(call->opcode()),
107                  argument_count == JSCallAccessor(call).argument_count());
108 
109   // The scheduler is smart enough to place our code; we just ensure {control}
110   // becomes the control input of the start of the inlinee, and {effect} becomes
111   // the effect input of the start of the inlinee.
112   Node* control = NodeProperties::GetControlInput(call);
113   Node* effect = NodeProperties::GetEffectInput(call);
114 
115   int const inlinee_new_target_index = start.NewTargetOutputIndex();
116   int const inlinee_arity_index = start.ArgCountOutputIndex();
117   int const inlinee_context_index = start.ContextOutputIndex();
118 
119   // {inliner_inputs} counts the target, receiver/new_target, and arguments; but
120   // not feedback vector, context, effect or control.
121   const int inliner_inputs = argument_count +
122                              JSCallOrConstructNode::kExtraInputCount -
123                              JSCallOrConstructNode::kFeedbackVectorInputCount;
124   // Iterate over all uses of the start node.
125   for (Edge edge : start->use_edges()) {
126     Node* use = edge.from();
127     switch (use->opcode()) {
128       case IrOpcode::kParameter: {
129         int index = 1 + ParameterIndexOf(use->op());
130         DCHECK_LE(index, inlinee_context_index);
131         if (index < inliner_inputs && index < inlinee_new_target_index) {
132           // There is an input from the call, and the index is a value
133           // projection but not the context, so rewire the input.
134           Replace(use, call->InputAt(index));
135         } else if (index == inlinee_new_target_index) {
136           // The projection is requesting the new target value.
137           Replace(use, new_target);
138         } else if (index == inlinee_arity_index) {
139           // The projection is requesting the number of arguments.
140           Replace(use, jsgraph()->Constant(argument_count));
141         } else if (index == inlinee_context_index) {
142           // The projection is requesting the inlinee function context.
143           Replace(use, context);
144         } else {
145           // Call has fewer arguments than required, fill with undefined.
146           Replace(use, jsgraph()->UndefinedConstant());
147         }
148         break;
149       }
150       default:
151         if (NodeProperties::IsEffectEdge(edge)) {
152           edge.UpdateTo(effect);
153         } else if (NodeProperties::IsControlEdge(edge)) {
154           edge.UpdateTo(control);
155         } else if (NodeProperties::IsFrameStateEdge(edge)) {
156           edge.UpdateTo(frame_state);
157         } else {
158           UNREACHABLE();
159         }
160         break;
161     }
162   }
163 
164   if (exception_target != nullptr) {
165     // Link uncaught calls in the inlinee to {exception_target}
166     int subcall_count = static_cast<int>(uncaught_subcalls.size());
167     if (subcall_count > 0) {
168       TRACE("Inlinee contains " << subcall_count
169                                 << " calls without local exception handler; "
170                                 << "linking to surrounding exception handler.");
171     }
172     NodeVector on_exception_nodes(local_zone_);
173     for (Node* subcall : uncaught_subcalls) {
174       Node* on_success = graph()->NewNode(common()->IfSuccess(), subcall);
175       NodeProperties::ReplaceUses(subcall, subcall, subcall, on_success);
176       NodeProperties::ReplaceControlInput(on_success, subcall);
177       Node* on_exception =
178           graph()->NewNode(common()->IfException(), subcall, subcall);
179       on_exception_nodes.push_back(on_exception);
180     }
181 
182     DCHECK_EQ(subcall_count, static_cast<int>(on_exception_nodes.size()));
183     if (subcall_count > 0) {
184       Node* control_output =
185           graph()->NewNode(common()->Merge(subcall_count), subcall_count,
186                            &on_exception_nodes.front());
187       NodeVector values_effects(local_zone_);
188       values_effects = on_exception_nodes;
189       values_effects.push_back(control_output);
190       Node* value_output = graph()->NewNode(
191           common()->Phi(MachineRepresentation::kTagged, subcall_count),
192           subcall_count + 1, &values_effects.front());
193       Node* effect_output =
194           graph()->NewNode(common()->EffectPhi(subcall_count),
195                            subcall_count + 1, &values_effects.front());
196       ReplaceWithValue(exception_target, value_output, effect_output,
197                        control_output);
198     } else {
199       ReplaceWithValue(exception_target, exception_target, exception_target,
200                        jsgraph()->Dead());
201     }
202   }
203 
204   NodeVector values(local_zone_);
205   NodeVector effects(local_zone_);
206   NodeVector controls(local_zone_);
207   for (Node* const input : end->inputs()) {
208     switch (input->opcode()) {
209       case IrOpcode::kReturn:
210         values.push_back(NodeProperties::GetValueInput(input, 1));
211         effects.push_back(NodeProperties::GetEffectInput(input));
212         controls.push_back(NodeProperties::GetControlInput(input));
213         break;
214       case IrOpcode::kDeoptimize:
215       case IrOpcode::kTerminate:
216       case IrOpcode::kThrow:
217         NodeProperties::MergeControlToEnd(graph(), common(), input);
218         Revisit(graph()->end());
219         break;
220       default:
221         UNREACHABLE();
222     }
223   }
224   DCHECK_EQ(values.size(), effects.size());
225   DCHECK_EQ(values.size(), controls.size());
226 
227   // Depending on whether the inlinee produces a value, we either replace value
228   // uses with said value or kill value uses if no value can be returned.
229   if (values.size() > 0) {
230     int const input_count = static_cast<int>(controls.size());
231     Node* control_output = graph()->NewNode(common()->Merge(input_count),
232                                             input_count, &controls.front());
233     values.push_back(control_output);
234     effects.push_back(control_output);
235     Node* value_output = graph()->NewNode(
236         common()->Phi(MachineRepresentation::kTagged, input_count),
237         static_cast<int>(values.size()), &values.front());
238     Node* effect_output =
239         graph()->NewNode(common()->EffectPhi(input_count),
240                          static_cast<int>(effects.size()), &effects.front());
241     ReplaceWithValue(call, value_output, effect_output, control_output);
242     return Changed(value_output);
243   } else {
244     ReplaceWithValue(call, jsgraph()->Dead(), jsgraph()->Dead(),
245                      jsgraph()->Dead());
246     return Changed(call);
247   }
248 }
249 
CreateArtificialFrameState(Node * node,FrameState outer_frame_state,int parameter_count,BytecodeOffset bailout_id,FrameStateType frame_state_type,SharedFunctionInfoRef shared,Node * context)250 FrameState JSInliner::CreateArtificialFrameState(
251     Node* node, FrameState outer_frame_state, int parameter_count,
252     BytecodeOffset bailout_id, FrameStateType frame_state_type,
253     SharedFunctionInfoRef shared, Node* context) {
254   const int parameter_count_with_receiver =
255       parameter_count + JSCallOrConstructNode::kReceiverOrNewTargetInputCount;
256   const FrameStateFunctionInfo* state_info =
257       common()->CreateFrameStateFunctionInfo(
258           frame_state_type, parameter_count_with_receiver, 0, shared.object());
259 
260   const Operator* op = common()->FrameState(
261       bailout_id, OutputFrameStateCombine::Ignore(), state_info);
262   const Operator* op0 = common()->StateValues(0, SparseInputMask::Dense());
263   Node* node0 = graph()->NewNode(op0);
264 
265   NodeVector params(local_zone_);
266   params.push_back(
267       node->InputAt(JSCallOrConstructNode::ReceiverOrNewTargetIndex()));
268   for (int i = 0; i < parameter_count; i++) {
269     params.push_back(node->InputAt(JSCallOrConstructNode::ArgumentIndex(i)));
270   }
271   const Operator* op_param = common()->StateValues(
272       static_cast<int>(params.size()), SparseInputMask::Dense());
273   Node* params_node = graph()->NewNode(
274       op_param, static_cast<int>(params.size()), &params.front());
275   if (context == nullptr) context = jsgraph()->UndefinedConstant();
276   return FrameState{graph()->NewNode(
277       op, params_node, node0, node0, context,
278       node->InputAt(JSCallOrConstructNode::TargetIndex()), outer_frame_state)};
279 }
280 
281 namespace {
282 
NeedsImplicitReceiver(SharedFunctionInfoRef shared_info)283 bool NeedsImplicitReceiver(SharedFunctionInfoRef shared_info) {
284   DisallowGarbageCollection no_gc;
285   return !shared_info.construct_as_builtin() &&
286          !IsDerivedConstructor(shared_info.kind());
287 }
288 
289 }  // namespace
290 
291 // Determines whether the call target of the given call {node} is statically
292 // known and can be used as an inlining candidate. The {SharedFunctionInfo} of
293 // the call target is provided (the exact closure might be unknown).
DetermineCallTarget(Node * node)294 base::Optional<SharedFunctionInfoRef> JSInliner::DetermineCallTarget(
295     Node* node) {
296   DCHECK(IrOpcode::IsInlineeOpcode(node->opcode()));
297   Node* target = node->InputAt(JSCallOrConstructNode::TargetIndex());
298   HeapObjectMatcher match(target);
299 
300   // This reducer can handle both normal function calls as well a constructor
301   // calls whenever the target is a constant function object, as follows:
302   //  - JSCall(target:constant, receiver, args..., vector)
303   //  - JSConstruct(target:constant, new.target, args..., vector)
304   if (match.HasResolvedValue() && match.Ref(broker()).IsJSFunction()) {
305     JSFunctionRef function = match.Ref(broker()).AsJSFunction();
306 
307     // The function might have not been called yet.
308     if (!function.feedback_vector(broker()->dependencies()).has_value()) {
309       return base::nullopt;
310     }
311 
312     // Disallow cross native-context inlining for now. This means that all parts
313     // of the resulting code will operate on the same global object. This also
314     // prevents cross context leaks, where we could inline functions from a
315     // different context and hold on to that context (and closure) from the code
316     // object.
317     // TODO(turbofan): We might want to revisit this restriction later when we
318     // have a need for this, and we know how to model different native contexts
319     // in the same graph in a compositional way.
320     if (!function.native_context().equals(broker()->target_native_context())) {
321       return base::nullopt;
322     }
323 
324     return function.shared();
325   }
326 
327   // This reducer can also handle calls where the target is statically known to
328   // be the result of a closure instantiation operation, as follows:
329   //  - JSCall(JSCreateClosure[shared](context), receiver, args..., vector)
330   //  - JSConstruct(JSCreateClosure[shared](context),
331   //                new.target, args..., vector)
332   if (match.IsJSCreateClosure()) {
333     JSCreateClosureNode n(target);
334     FeedbackCellRef cell = n.GetFeedbackCellRefChecked(broker());
335     return cell.shared_function_info();
336   } else if (match.IsCheckClosure()) {
337     FeedbackCellRef cell = MakeRef(broker(), FeedbackCellOf(match.op()));
338     return cell.shared_function_info();
339   }
340 
341   return base::nullopt;
342 }
343 
344 // Determines statically known information about the call target (assuming that
345 // the call target is known according to {DetermineCallTarget} above). The
346 // following static information is provided:
347 //  - context         : The context (as SSA value) bound by the call target.
348 //  - feedback_vector : The target is guaranteed to use this feedback vector.
DetermineCallContext(Node * node,Node ** context_out)349 FeedbackCellRef JSInliner::DetermineCallContext(Node* node,
350                                                 Node** context_out) {
351   DCHECK(IrOpcode::IsInlineeOpcode(node->opcode()));
352   Node* target = node->InputAt(JSCallOrConstructNode::TargetIndex());
353   HeapObjectMatcher match(target);
354 
355   if (match.HasResolvedValue() && match.Ref(broker()).IsJSFunction()) {
356     JSFunctionRef function = match.Ref(broker()).AsJSFunction();
357     // This was already ensured by DetermineCallTarget
358     CHECK(function.feedback_vector(broker()->dependencies()).has_value());
359 
360     // The inlinee specializes to the context from the JSFunction object.
361     *context_out = jsgraph()->Constant(function.context());
362     return function.raw_feedback_cell(broker()->dependencies());
363   }
364 
365   if (match.IsJSCreateClosure()) {
366     // Load the feedback vector of the target by looking up its vector cell at
367     // the instantiation site (we only decide to inline if it's populated).
368     JSCreateClosureNode n(target);
369     FeedbackCellRef cell = n.GetFeedbackCellRefChecked(broker());
370 
371     // The inlinee uses the locally provided context at instantiation.
372     *context_out = NodeProperties::GetContextInput(match.node());
373     return cell;
374   } else if (match.IsCheckClosure()) {
375     FeedbackCellRef cell = MakeRef(broker(), FeedbackCellOf(match.op()));
376 
377     Node* effect = NodeProperties::GetEffectInput(node);
378     Node* control = NodeProperties::GetControlInput(node);
379     *context_out = effect = graph()->NewNode(
380         simplified()->LoadField(AccessBuilder::ForJSFunctionContext()),
381         match.node(), effect, control);
382     NodeProperties::ReplaceEffectInput(node, effect);
383 
384     return cell;
385   }
386 
387   // Must succeed.
388   UNREACHABLE();
389 }
390 
391 #if V8_ENABLE_WEBASSEMBLY
ReduceJSWasmCall(Node * node)392 Reduction JSInliner::ReduceJSWasmCall(Node* node) {
393   // Create the subgraph for the inlinee.
394   Node* start_node;
395   Node* end;
396   size_t subgraph_min_node_id;
397   {
398     Graph::SubgraphScope scope(graph());
399 
400     graph()->SetEnd(nullptr);
401 
402     JSWasmCallNode n(node);
403     const JSWasmCallParameters& wasm_call_params = n.Parameters();
404 
405     // Create a nested frame state inside the frame state attached to the
406     // call; this will ensure that lazy deoptimizations at this point will
407     // still return the result of the Wasm function call.
408     Node* continuation_frame_state =
409         CreateJSWasmCallBuiltinContinuationFrameState(
410             jsgraph(), n.context(), n.frame_state(),
411             wasm_call_params.signature());
412     JSWasmCallData js_wasm_call_data(wasm_call_params.signature());
413 
414     // All the nodes inserted by the inlined subgraph will have
415     // id >= subgraph_min_node_id. We use this later to avoid wire nodes that
416     // are not inserted by the inlinee but were already part of the graph to the
417     // surrounding exception handler, if present.
418     subgraph_min_node_id = graph()->NodeCount();
419 
420     BuildInlinedJSToWasmWrapper(
421         graph()->zone(), jsgraph(), wasm_call_params.signature(),
422         wasm_call_params.module(), isolate(), source_positions_,
423         StubCallMode::kCallBuiltinPointer, wasm::WasmFeatures::FromFlags(),
424         &js_wasm_call_data, continuation_frame_state);
425 
426     // Extract the inlinee start/end nodes.
427     start_node = graph()->start();
428     end = graph()->end();
429   }
430   StartNode start{start_node};
431 
432   Node* exception_target = nullptr;
433   NodeProperties::IsExceptionalCall(node, &exception_target);
434 
435   // If we are inlining into a surrounding exception handler, we collect all
436   // potentially throwing nodes within the inlinee that are not handled locally
437   // by the inlinee itself. They are later wired into the surrounding handler.
438   NodeVector uncaught_subcalls(local_zone_);
439   if (exception_target != nullptr) {
440     // Find all uncaught 'calls' in the inlinee.
441     AllNodes inlined_nodes(local_zone_, end, graph());
442     for (Node* subnode : inlined_nodes.reachable) {
443       // Ignore nodes that are not part of the inlinee.
444       if (subnode->id() < subgraph_min_node_id) continue;
445 
446       // Every possibly throwing node should get {IfSuccess} and {IfException}
447       // projections, unless there already is local exception handling.
448       if (subnode->op()->HasProperty(Operator::kNoThrow)) continue;
449       if (!NodeProperties::IsExceptionalCall(subnode)) {
450         DCHECK_EQ(2, subnode->op()->ControlOutputCount());
451         uncaught_subcalls.push_back(subnode);
452       }
453     }
454   }
455 
456   Node* context = NodeProperties::GetContextInput(node);
457   Node* frame_state = NodeProperties::GetFrameStateInput(node);
458   Node* new_target = jsgraph()->UndefinedConstant();
459 
460   return InlineJSWasmCall(node, new_target, context, frame_state, start, end,
461                           exception_target, uncaught_subcalls);
462 }
463 #endif  // V8_ENABLE_WEBASSEMBLY
464 
ReduceJSCall(Node * node)465 Reduction JSInliner::ReduceJSCall(Node* node) {
466   DCHECK(IrOpcode::IsInlineeOpcode(node->opcode()));
467 #if V8_ENABLE_WEBASSEMBLY
468   DCHECK_NE(node->opcode(), IrOpcode::kJSWasmCall);
469 #endif  // V8_ENABLE_WEBASSEMBLY
470   JSCallAccessor call(node);
471 
472   // Determine the call target.
473   base::Optional<SharedFunctionInfoRef> shared_info(DetermineCallTarget(node));
474   if (!shared_info.has_value()) return NoChange();
475 
476   SharedFunctionInfoRef outer_shared_info =
477       MakeRef(broker(), info_->shared_info());
478 
479   SharedFunctionInfo::Inlineability inlineability =
480       shared_info->GetInlineability();
481   if (inlineability != SharedFunctionInfo::kIsInlineable) {
482     // The function is no longer inlineable. The only way this can happen is if
483     // the function had its optimization disabled in the meantime, e.g. because
484     // another optimization job failed too often.
485     CHECK_EQ(inlineability, SharedFunctionInfo::kHasOptimizationDisabled);
486     TRACE("Not inlining " << *shared_info << " into " << outer_shared_info
487                           << " because it had its optimization disabled.");
488     return NoChange();
489   }
490   // NOTE: Even though we bailout in the kHasOptimizationDisabled case above, we
491   // won't notice if the function's optimization is disabled after this point.
492 
493   // Constructor must be constructable.
494   if (node->opcode() == IrOpcode::kJSConstruct &&
495       !IsConstructable(shared_info->kind())) {
496     TRACE("Not inlining " << *shared_info << " into " << outer_shared_info
497                           << " because constructor is not constructable.");
498     return NoChange();
499   }
500 
501   // Class constructors are callable, but [[Call]] will raise an exception.
502   // See ES6 section 9.2.1 [[Call]] ( thisArgument, argumentsList ).
503   if (node->opcode() == IrOpcode::kJSCall &&
504       IsClassConstructor(shared_info->kind())) {
505     TRACE("Not inlining " << *shared_info << " into " << outer_shared_info
506                           << " because callee is a class constructor.");
507     return NoChange();
508   }
509 
510   // To ensure inlining always terminates, we have an upper limit on inlining
511   // the nested calls.
512   int nesting_level = 0;
513   for (Node* frame_state = call.frame_state();
514        frame_state->opcode() == IrOpcode::kFrameState;
515        frame_state = FrameState{frame_state}.outer_frame_state()) {
516     nesting_level++;
517     if (nesting_level > kMaxDepthForInlining) {
518       TRACE("Not inlining "
519             << *shared_info << " into " << outer_shared_info
520             << " because call has exceeded the maximum depth for function "
521                "inlining.");
522       return NoChange();
523     }
524   }
525 
526   Node* exception_target = nullptr;
527   NodeProperties::IsExceptionalCall(node, &exception_target);
528 
529   // JSInliningHeuristic has already filtered candidates without a BytecodeArray
530   // based on SharedFunctionInfoRef::GetInlineability. For the inlineable ones
531   // (kIsInlineable), the broker holds a reference to the bytecode array, which
532   // prevents it from getting flushed.  Therefore, the following check should
533   // always hold true.
534   CHECK(shared_info->is_compiled());
535 
536   if (info_->source_positions() &&
537       !shared_info->object()->AreSourcePositionsAvailable(
538           broker()->local_isolate_or_isolate())) {
539     // This case is expected to be very rare, since we generate source
540     // positions for all functions when debugging or profiling are turned
541     // on (see Isolate::NeedsDetailedOptimizedCodeLineInfo). Source
542     // positions should only be missing here if there is a race between 1)
543     // enabling/disabling the debugger/profiler, and 2) this compile job.
544     // In that case, we simply don't inline.
545     TRACE("Not inlining " << *shared_info << " into " << outer_shared_info
546                           << " because source positions are missing.");
547     return NoChange();
548   }
549 
550   // Determine the target's feedback vector and its context.
551   Node* context;
552   FeedbackCellRef feedback_cell = DetermineCallContext(node, &context);
553 
554   TRACE("Inlining " << *shared_info << " into " << outer_shared_info
555                     << ((exception_target != nullptr) ? " (inside try-block)"
556                                                       : ""));
557   // ----------------------------------------------------------------
558   // After this point, we've made a decision to inline this function.
559   // We shall not bailout from inlining if we got here.
560 
561   BytecodeArrayRef bytecode_array = shared_info->GetBytecodeArray();
562 
563   // Remember that we inlined this function.
564   int inlining_id =
565       info_->AddInlinedFunction(shared_info->object(), bytecode_array.object(),
566                                 source_positions_->GetSourcePosition(node));
567 
568   // Create the subgraph for the inlinee.
569   Node* start_node;
570   Node* end;
571   {
572     // Run the BytecodeGraphBuilder to create the subgraph.
573     Graph::SubgraphScope scope(graph());
574     BytecodeGraphBuilderFlags flags(
575         BytecodeGraphBuilderFlag::kSkipFirstStackAndTierupCheck);
576     if (info_->analyze_environment_liveness()) {
577       flags |= BytecodeGraphBuilderFlag::kAnalyzeEnvironmentLiveness;
578     }
579     if (info_->bailout_on_uninitialized()) {
580       flags |= BytecodeGraphBuilderFlag::kBailoutOnUninitialized;
581     }
582     {
583       CallFrequency frequency = call.frequency();
584       BuildGraphFromBytecode(broker(), zone(), *shared_info, feedback_cell,
585                              BytecodeOffset::None(), jsgraph(), frequency,
586                              source_positions_, inlining_id, info_->code_kind(),
587                              flags, &info_->tick_counter());
588     }
589 
590     // Extract the inlinee start/end nodes.
591     start_node = graph()->start();
592     end = graph()->end();
593   }
594   StartNode start{start_node};
595 
596   // If we are inlining into a surrounding exception handler, we collect all
597   // potentially throwing nodes within the inlinee that are not handled locally
598   // by the inlinee itself. They are later wired into the surrounding handler.
599   NodeVector uncaught_subcalls(local_zone_);
600   if (exception_target != nullptr) {
601     // Find all uncaught 'calls' in the inlinee.
602     AllNodes inlined_nodes(local_zone_, end, graph());
603     for (Node* subnode : inlined_nodes.reachable) {
604       // Every possibly throwing node should get {IfSuccess} and {IfException}
605       // projections, unless there already is local exception handling.
606       if (subnode->op()->HasProperty(Operator::kNoThrow)) continue;
607       if (!NodeProperties::IsExceptionalCall(subnode)) {
608         DCHECK_EQ(2, subnode->op()->ControlOutputCount());
609         uncaught_subcalls.push_back(subnode);
610       }
611     }
612   }
613 
614   FrameState frame_state = call.frame_state();
615   Node* new_target = jsgraph()->UndefinedConstant();
616 
617   // Inline {JSConstruct} requires some additional magic.
618   if (node->opcode() == IrOpcode::kJSConstruct) {
619     STATIC_ASSERT(JSCallOrConstructNode::kHaveIdenticalLayouts);
620     JSConstructNode n(node);
621 
622     new_target = n.new_target();
623 
624     // Insert nodes around the call that model the behavior required for a
625     // constructor dispatch (allocate implicit receiver and check return value).
626     // This models the behavior usually accomplished by our {JSConstructStub}.
627     // Note that the context has to be the callers context (input to call node).
628     // Also note that by splitting off the {JSCreate} piece of the constructor
629     // call, we create an observable deoptimization point after the receiver
630     // instantiation but before the invocation (i.e. inside {JSConstructStub}
631     // where execution continues at {construct_stub_create_deopt_pc_offset}).
632     Node* receiver = jsgraph()->TheHoleConstant();  // Implicit receiver.
633     Node* caller_context = NodeProperties::GetContextInput(node);
634     if (NeedsImplicitReceiver(*shared_info)) {
635       Effect effect = n.effect();
636       Control control = n.control();
637       Node* frame_state_inside = CreateArtificialFrameState(
638           node, frame_state, n.ArgumentCount(),
639           BytecodeOffset::ConstructStubCreate(), FrameStateType::kConstructStub,
640           *shared_info, caller_context);
641       Node* create =
642           graph()->NewNode(javascript()->Create(), call.target(), new_target,
643                            caller_context, frame_state_inside, effect, control);
644       uncaught_subcalls.push_back(create);  // Adds {IfSuccess} & {IfException}.
645       NodeProperties::ReplaceControlInput(node, create);
646       NodeProperties::ReplaceEffectInput(node, create);
647       // Placeholder to hold {node}'s value dependencies while {node} is
648       // replaced.
649       Node* dummy = graph()->NewNode(common()->Dead());
650       NodeProperties::ReplaceUses(node, dummy, node, node, node);
651       Node* result;
652       // Insert a check of the return value to determine whether the return
653       // value or the implicit receiver should be selected as a result of the
654       // call.
655       Node* check = graph()->NewNode(simplified()->ObjectIsReceiver(), node);
656       result =
657           graph()->NewNode(common()->Select(MachineRepresentation::kTagged),
658                            check, node, create);
659       receiver = create;  // The implicit receiver.
660       ReplaceWithValue(dummy, result);
661     } else if (IsDerivedConstructor(shared_info->kind())) {
662       Node* node_success =
663           NodeProperties::FindSuccessfulControlProjection(node);
664       Node* is_receiver =
665           graph()->NewNode(simplified()->ObjectIsReceiver(), node);
666       Node* branch_is_receiver =
667           graph()->NewNode(common()->Branch(), is_receiver, node_success);
668       Node* branch_is_receiver_true =
669           graph()->NewNode(common()->IfTrue(), branch_is_receiver);
670       Node* branch_is_receiver_false =
671           graph()->NewNode(common()->IfFalse(), branch_is_receiver);
672       branch_is_receiver_false = graph()->NewNode(
673           javascript()->CallRuntime(
674               Runtime::kThrowConstructorReturnedNonObject),
675           caller_context, NodeProperties::GetFrameStateInput(node), node,
676           branch_is_receiver_false);
677       uncaught_subcalls.push_back(branch_is_receiver_false);
678       branch_is_receiver_false =
679           graph()->NewNode(common()->Throw(), branch_is_receiver_false,
680                            branch_is_receiver_false);
681       NodeProperties::MergeControlToEnd(graph(), common(),
682                                         branch_is_receiver_false);
683 
684       ReplaceWithValue(node_success, node_success, node_success,
685                        branch_is_receiver_true);
686       // Fix input destroyed by the above {ReplaceWithValue} call.
687       NodeProperties::ReplaceControlInput(branch_is_receiver, node_success, 0);
688     }
689     node->ReplaceInput(JSCallNode::ReceiverIndex(), receiver);
690     // Insert a construct stub frame into the chain of frame states. This will
691     // reconstruct the proper frame when deoptimizing within the constructor.
692     frame_state = CreateArtificialFrameState(
693         node, frame_state, n.ArgumentCount(),
694         BytecodeOffset::ConstructStubInvoke(), FrameStateType::kConstructStub,
695         *shared_info, caller_context);
696   }
697 
698   // Insert a JSConvertReceiver node for sloppy callees. Note that the context
699   // passed into this node has to be the callees context (loaded above).
700   if (node->opcode() == IrOpcode::kJSCall &&
701       is_sloppy(shared_info->language_mode()) && !shared_info->native()) {
702     Effect effect{NodeProperties::GetEffectInput(node)};
703     if (NodeProperties::CanBePrimitive(broker(), call.receiver(), effect)) {
704       CallParameters const& p = CallParametersOf(node->op());
705       Node* global_proxy = jsgraph()->Constant(
706           broker()->target_native_context().global_proxy_object());
707       Node* receiver = effect =
708           graph()->NewNode(simplified()->ConvertReceiver(p.convert_mode()),
709                            call.receiver(), global_proxy, effect, start);
710       NodeProperties::ReplaceValueInput(node, receiver,
711                                         JSCallNode::ReceiverIndex());
712       NodeProperties::ReplaceEffectInput(node, effect);
713     }
714   }
715 
716   // Insert argument adaptor frame if required. The callees formal parameter
717   // count have to match the number of arguments passed
718   // to the call.
719   int parameter_count =
720       shared_info->internal_formal_parameter_count_without_receiver();
721   DCHECK_EQ(parameter_count, start.FormalParameterCountWithoutReceiver());
722   if (call.argument_count() != parameter_count) {
723     frame_state = CreateArtificialFrameState(
724         node, frame_state, call.argument_count(), BytecodeOffset::None(),
725         FrameStateType::kArgumentsAdaptor, *shared_info);
726   }
727 
728   return InlineCall(node, new_target, context, frame_state, start, end,
729                     exception_target, uncaught_subcalls, call.argument_count());
730 }
731 
graph() const732 Graph* JSInliner::graph() const { return jsgraph()->graph(); }
733 
javascript() const734 JSOperatorBuilder* JSInliner::javascript() const {
735   return jsgraph()->javascript();
736 }
737 
common() const738 CommonOperatorBuilder* JSInliner::common() const { return jsgraph()->common(); }
739 
simplified() const740 SimplifiedOperatorBuilder* JSInliner::simplified() const {
741   return jsgraph()->simplified();
742 }
743 
744 #undef TRACE
745 
746 }  // namespace compiler
747 }  // namespace internal
748 }  // namespace v8
749