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.
5 #ifndef V8_COMPILER_AST_GRAPH_BUILDER_H_
6 #define V8_COMPILER_AST_GRAPH_BUILDER_H_
9 #include "src/compiler/js-graph.h"
10 #include "src/compiler/liveness-analyzer.h"
11 #include "src/compiler/state-values-utils.h"
22 class JSTypeFeedbackTable;
23 class LoopAssignmentAnalysis;
27 // The AstGraphBuilder produces a high-level IR graph, based on an
28 // underlying AST. The produced graph can either be compiled into a
29 // stand-alone function or be wired into another graph for the purposes
30 // of function inlining.
31 class AstGraphBuilder : public AstVisitor {
33 AstGraphBuilder(Zone* local_zone, CompilationInfo* info, JSGraph* jsgraph,
34 LoopAssignmentAnalysis* loop_assignment = NULL,
35 JSTypeFeedbackTable* js_type_feedback = NULL);
37 // Creates a graph by visiting the entire AST.
38 bool CreateGraph(bool constant_context, bool stack_check = true);
40 // Helpers to create new control nodes.
41 Node* NewIfTrue() { return NewNode(common()->IfTrue()); }
42 Node* NewIfFalse() { return NewNode(common()->IfFalse()); }
43 Node* NewMerge() { return NewNode(common()->Merge(1), true); }
44 Node* NewLoop() { return NewNode(common()->Loop(1), true); }
45 Node* NewBranch(Node* condition, BranchHint hint = BranchHint::kNone) {
46 return NewNode(common()->Branch(hint), condition);
50 #define DECLARE_VISIT(type) void Visit##type(type* node) OVERRIDE;
51 // Visiting functions for AST nodes make this an AstVisitor.
52 AST_NODE_LIST(DECLARE_VISIT)
55 // Visiting function for declarations list is overridden.
56 void VisitDeclarations(ZoneList<Declaration*>* declarations) OVERRIDE;
60 class AstEffectContext;
61 class AstValueContext;
65 class ControlScopeForBreakable;
66 class ControlScopeForIteration;
67 class ControlScopeForCatch;
68 class ControlScopeForFinally;
70 friend class ControlBuilder;
73 CompilationInfo* info_;
75 Environment* environment_;
76 AstContext* ast_context_;
78 // List of global declarations for functions and variables.
79 ZoneVector<Handle<Object>> globals_;
81 // Stack of control scopes currently entered by the visitor.
82 ControlScope* execution_control_;
84 // Stack of context objects pushed onto the chain by the visitor.
85 ContextScope* execution_context_;
87 // Nodes representing values in the activation record.
88 SetOncePointer<Node> function_closure_;
89 SetOncePointer<Node> function_context_;
91 // Tracks how many try-blocks are currently entered.
92 int try_nesting_level_;
94 // Temporary storage for building node input lists.
95 int input_buffer_size_;
98 // Merge of all control nodes that exit the function body.
101 // Result of loop assignment analysis performed before graph creation.
102 LoopAssignmentAnalysis* loop_assignment_analysis_;
104 // Cache for StateValues nodes for frame states.
105 StateValuesCache state_values_cache_;
107 // Analyzer of local variable liveness.
108 LivenessAnalyzer liveness_analyzer_;
110 // Type feedback table.
111 JSTypeFeedbackTable* js_type_feedback_;
113 // Growth increment for the temporary buffer used to construct input lists to
115 static const int kInputBufferSizeIncrement = 64;
117 Zone* local_zone() const { return local_zone_; }
118 Environment* environment() const { return environment_; }
119 AstContext* ast_context() const { return ast_context_; }
120 ControlScope* execution_control() const { return execution_control_; }
121 ContextScope* execution_context() const { return execution_context_; }
122 CommonOperatorBuilder* common() const { return jsgraph_->common(); }
123 CompilationInfo* info() const { return info_; }
124 LanguageMode language_mode() const;
125 JSGraph* jsgraph() { return jsgraph_; }
126 Graph* graph() { return jsgraph_->graph(); }
127 Zone* graph_zone() { return graph()->zone(); }
128 JSOperatorBuilder* javascript() { return jsgraph_->javascript(); }
129 ZoneVector<Handle<Object>>* globals() { return &globals_; }
130 Scope* current_scope() const;
131 Node* current_context() const;
132 Node* exit_control() const { return exit_control_; }
133 LivenessAnalyzer* liveness_analyzer() { return &liveness_analyzer_; }
135 void set_environment(Environment* env) { environment_ = env; }
136 void set_ast_context(AstContext* ctx) { ast_context_ = ctx; }
137 void set_execution_control(ControlScope* ctrl) { execution_control_ = ctrl; }
138 void set_execution_context(ContextScope* ctx) { execution_context_ = ctx; }
139 void set_exit_control(Node* exit) { exit_control_ = exit; }
141 // Create the main graph body by visiting the AST.
142 void CreateGraphBody(bool stack_check);
144 // Create the node that represents the outer context of the function.
145 void CreateFunctionContext(bool constant_context);
147 // Get or create the node that represents the outer function closure.
148 Node* GetFunctionClosure();
150 // Node creation helpers.
151 Node* NewNode(const Operator* op, bool incomplete = false) {
152 return MakeNode(op, 0, static_cast<Node**>(NULL), incomplete);
155 Node* NewNode(const Operator* op, Node* n1) {
156 return MakeNode(op, 1, &n1, false);
159 Node* NewNode(const Operator* op, Node* n1, Node* n2) {
160 Node* buffer[] = {n1, n2};
161 return MakeNode(op, arraysize(buffer), buffer, false);
164 Node* NewNode(const Operator* op, Node* n1, Node* n2, Node* n3) {
165 Node* buffer[] = {n1, n2, n3};
166 return MakeNode(op, arraysize(buffer), buffer, false);
169 Node* NewNode(const Operator* op, Node* n1, Node* n2, Node* n3, Node* n4) {
170 Node* buffer[] = {n1, n2, n3, n4};
171 return MakeNode(op, arraysize(buffer), buffer, false);
174 Node* NewNode(const Operator* op, Node* n1, Node* n2, Node* n3, Node* n4,
176 Node* buffer[] = {n1, n2, n3, n4, n5};
177 return MakeNode(op, arraysize(buffer), buffer, false);
180 Node* NewNode(const Operator* op, Node* n1, Node* n2, Node* n3, Node* n4,
181 Node* n5, Node* n6) {
182 Node* nodes[] = {n1, n2, n3, n4, n5, n6};
183 return MakeNode(op, arraysize(nodes), nodes, false);
186 Node* NewNode(const Operator* op, int value_input_count, Node** value_inputs,
187 bool incomplete = false) {
188 return MakeNode(op, value_input_count, value_inputs, incomplete);
191 // Creates a new Phi node having {count} input values.
192 Node* NewPhi(int count, Node* input, Node* control);
193 Node* NewEffectPhi(int count, Node* input, Node* control);
195 Node* NewOuterContextParam();
196 Node* NewCurrentContextOsrValue();
198 // Helpers for merging control, effect or value dependencies.
199 Node* MergeControl(Node* control, Node* other);
200 Node* MergeEffect(Node* value, Node* other, Node* control);
201 Node* MergeValue(Node* value, Node* other, Node* control);
203 // The main node creation chokepoint. Adds context, frame state, effect,
204 // and control dependencies depending on the operator.
205 Node* MakeNode(const Operator* op, int value_input_count, Node** value_inputs,
208 // Helper to indicate a node exits the function body.
209 void UpdateControlDependencyToLeaveFunction(Node* exit);
211 // Builds deoptimization for a given node.
212 void PrepareFrameState(
213 Node* node, BailoutId ast_id,
214 OutputFrameStateCombine combine = OutputFrameStateCombine::Ignore());
215 void PrepareFrameStateAfterAndBefore(Node* node, BailoutId ast_id,
216 OutputFrameStateCombine combine,
217 Node* frame_state_before);
219 BitVector* GetVariablesAssignedInLoop(IterationStatement* stmt);
221 // Check if the given statement is an OSR entry.
222 // If so, record the stack height into the compilation and return {true}.
223 bool CheckOsrEntry(IterationStatement* stmt);
225 // Computes local variable liveness and replaces dead variables in
226 // frame states with the undefined values.
227 void ClearNonLiveSlotsInFrameStates();
229 // Helper to wrap a Handle<T> into a Unique<T>.
231 Unique<T> MakeUnique(Handle<T> object) {
232 return Unique<T>::CreateUninitialized(object);
235 Node** EnsureInputBufferSize(int size);
237 // Named and keyed loads require a VectorSlotPair for successful lowering.
238 VectorSlotPair CreateVectorSlotPair(FeedbackVectorICSlot slot) const;
240 // ===========================================================================
241 // The following build methods all generate graph fragments and return one
242 // resulting node. The operand stack height remains the same, variables and
243 // other dependencies tracked by the environment might be mutated though.
245 // Builder to create a receiver check for sloppy mode.
246 Node* BuildPatchReceiverToGlobalProxy(Node* receiver);
248 // Builders to create local function and block contexts.
249 Node* BuildLocalFunctionContext(Node* context, Node* closure);
250 Node* BuildLocalBlockContext(Scope* scope);
252 // Builder to create an arguments object if it is used.
253 Node* BuildArgumentsObject(Variable* arguments);
255 // Builder to create an array of rest parameters if used
256 Node* BuildRestArgumentsArray(Variable* rest, int index);
258 // Builders for variable load and assignment.
259 Node* BuildVariableAssignment(Variable* var, Node* value, Token::Value op,
260 BailoutId bailout_id,
261 OutputFrameStateCombine state_combine =
262 OutputFrameStateCombine::Ignore());
263 Node* BuildVariableDelete(Variable* var, BailoutId bailout_id,
264 OutputFrameStateCombine state_combine);
265 Node* BuildVariableLoad(Variable* var, BailoutId bailout_id,
266 const VectorSlotPair& feedback,
267 ContextualMode mode = CONTEXTUAL);
269 // Builders for property loads and stores.
270 Node* BuildKeyedLoad(Node* receiver, Node* key,
271 const VectorSlotPair& feedback, TypeFeedbackId id);
272 Node* BuildNamedLoad(Node* receiver, Handle<Name> name,
273 const VectorSlotPair& feedback, TypeFeedbackId id,
274 ContextualMode mode = NOT_CONTEXTUAL);
275 Node* BuildKeyedStore(Node* receiver, Node* key, Node* value,
277 Node* BuildNamedStore(Node* receiver, Handle<Name>, Node* value,
280 // Builders for accessing the function context.
281 Node* BuildLoadBuiltinsObject();
282 Node* BuildLoadGlobalObject();
283 Node* BuildLoadGlobalProxy();
284 Node* BuildLoadClosure();
285 Node* BuildLoadObjectField(Node* object, int offset);
287 // Builders for accessing external references.
288 Node* BuildLoadExternal(ExternalReference ref, MachineType type);
289 Node* BuildStoreExternal(ExternalReference ref, MachineType type, Node* val);
291 // Builders for automatic type conversion.
292 Node* BuildToBoolean(Node* value);
293 Node* BuildToName(Node* value, BailoutId bailout_id);
295 // Builder for adding the [[HomeObject]] to a value if the value came from a
296 // function literal and needs a home object. Do nothing otherwise.
297 Node* BuildSetHomeObject(Node* value, Node* home_object, Expression* expr);
299 // Builders for error reporting at runtime.
300 Node* BuildThrowError(Node* exception, BailoutId bailout_id);
301 Node* BuildThrowReferenceError(Variable* var, BailoutId bailout_id);
302 Node* BuildThrowConstAssignError(BailoutId bailout_id);
304 // Builders for dynamic hole-checks at runtime.
305 Node* BuildHoleCheckSilent(Node* value, Node* for_hole, Node* not_hole);
306 Node* BuildHoleCheckThrow(Node* value, Variable* var, Node* not_hole,
307 BailoutId bailout_id);
309 // Builders for conditional errors.
310 Node* BuildThrowIfStaticPrototype(Node* name, BailoutId bailout_id);
312 // Builders for non-local control flow.
313 Node* BuildReturn(Node* return_value);
314 Node* BuildThrow(Node* exception_value);
316 // Builders for binary operations.
317 Node* BuildBinaryOp(Node* left, Node* right, Token::Value op);
319 // Process arguments to a call by popping {arity} elements off the operand
320 // stack and build a call node using the given call operator.
321 Node* ProcessArguments(const Operator* op, int arity);
323 // ===========================================================================
324 // The following visitation methods all recursively visit a subtree of the
325 // underlying AST and extent the graph. The operand stack is mutated in a way
326 // consistent with other compilers:
327 // - Expressions pop operands and push result, depending on {AstContext}.
328 // - Statements keep the operand stack balanced.
331 void VisitIfNotNull(Statement* stmt);
333 // Visit expressions.
334 void Visit(Expression* expr);
335 void VisitForTest(Expression* expr);
336 void VisitForEffect(Expression* expr);
337 void VisitForValue(Expression* expr);
338 void VisitForValueOrNull(Expression* expr);
339 void VisitForValueOrTheHole(Expression* expr);
340 void VisitForValues(ZoneList<Expression*>* exprs);
342 // Common for all IterationStatement bodies.
343 void VisitIterationBody(IterationStatement* stmt, LoopBuilder* loop);
345 // Dispatched from VisitCallRuntime.
346 void VisitCallJSRuntime(CallRuntime* expr);
348 // Dispatched from VisitUnaryOperation.
349 void VisitDelete(UnaryOperation* expr);
350 void VisitVoid(UnaryOperation* expr);
351 void VisitTypeof(UnaryOperation* expr);
352 void VisitNot(UnaryOperation* expr);
354 // Dispatched from VisitBinaryOperation.
355 void VisitComma(BinaryOperation* expr);
356 void VisitLogicalExpression(BinaryOperation* expr);
357 void VisitArithmeticExpression(BinaryOperation* expr);
359 // Dispatched from VisitForInStatement.
360 void VisitForInAssignment(Expression* expr, Node* value,
361 BailoutId bailout_id);
362 void VisitForInBody(ForInStatement* stmt);
364 // Dispatched from VisitClassLiteral.
365 void VisitClassLiteralContents(ClassLiteral* expr);
367 DEFINE_AST_VISITOR_SUBCLASS_MEMBERS();
368 DISALLOW_COPY_AND_ASSIGN(AstGraphBuilder);
372 // The abstract execution environment for generated code consists of
373 // parameter variables, local variables and the operand stack. The
374 // environment will perform proper SSA-renaming of all tracked nodes
375 // at split and merge points in the control flow. Internally all the
376 // values are stored in one list using the following layout:
378 // [parameters (+receiver)] [locals] [operand stack]
380 class AstGraphBuilder::Environment : public ZoneObject {
382 Environment(AstGraphBuilder* builder, Scope* scope, Node* control_dependency);
384 int parameters_count() const { return parameters_count_; }
385 int locals_count() const { return locals_count_; }
387 return static_cast<int>(values()->size()) - parameters_count_ -
391 // Operations on parameter or local variables.
392 void Bind(Variable* variable, Node* node);
393 Node* Lookup(Variable* variable);
394 void MarkAllLocalsLive();
396 Node* Context() const { return contexts_.back(); }
397 void PushContext(Node* context) { contexts()->push_back(context); }
398 void PopContext() { contexts()->pop_back(); }
400 // Operations on the operand stack.
401 void Push(Node* node) {
402 values()->push_back(node);
405 DCHECK(stack_height() > 0);
406 return values()->back();
409 DCHECK(stack_height() > 0);
410 Node* back = values()->back();
411 values()->pop_back();
415 // Direct mutations of the operand stack.
416 void Poke(int depth, Node* node) {
417 DCHECK(depth >= 0 && depth < stack_height());
418 int index = static_cast<int>(values()->size()) - depth - 1;
419 values()->at(index) = node;
421 Node* Peek(int depth) {
422 DCHECK(depth >= 0 && depth < stack_height());
423 int index = static_cast<int>(values()->size()) - depth - 1;
424 return values()->at(index);
426 void Drop(int depth) {
427 DCHECK(depth >= 0 && depth <= stack_height());
428 values()->erase(values()->end() - depth, values()->end());
430 void Trim(int trim_to_height) {
431 int depth = stack_height() - trim_to_height;
432 DCHECK(depth >= 0 && depth <= stack_height());
433 values()->erase(values()->end() - depth, values()->end());
436 // Preserve a checkpoint of the environment for the IR graph. Any
437 // further mutation of the environment will not affect checkpoints.
438 Node* Checkpoint(BailoutId ast_id, OutputFrameStateCombine combine =
439 OutputFrameStateCombine::Ignore());
441 // Control dependency tracked by this environment.
442 Node* GetControlDependency() { return control_dependency_; }
443 void UpdateControlDependency(Node* dependency) {
444 control_dependency_ = dependency;
447 // Effect dependency tracked by this environment.
448 Node* GetEffectDependency() { return effect_dependency_; }
449 void UpdateEffectDependency(Node* dependency) {
450 effect_dependency_ = dependency;
453 // Mark this environment as being unreachable.
454 void MarkAsUnreachable() {
455 UpdateControlDependency(builder()->jsgraph()->DeadControl());
457 bool IsMarkedAsUnreachable() {
458 return GetControlDependency()->opcode() == IrOpcode::kDead;
461 // Merge another environment into this one.
462 void Merge(Environment* other);
464 // Copies this environment at a control-flow split point.
465 Environment* CopyForConditional() { return Copy(); }
467 // Copies this environment to a potentially unreachable control-flow point.
468 Environment* CopyAsUnreachable() {
469 Environment* env = Copy();
470 env->MarkAsUnreachable();
474 // Copies this environment at a loop header control-flow point.
475 Environment* CopyForLoop(BitVector* assigned, bool is_osr = false) {
476 PrepareForLoop(assigned, is_osr);
477 return CopyAndShareLiveness();
480 int ContextStackDepth() { return static_cast<int>(contexts_.size()); }
483 AstGraphBuilder* builder_;
484 int parameters_count_;
486 LivenessAnalyzerBlock* liveness_block_;
488 NodeVector contexts_;
489 Node* control_dependency_;
490 Node* effect_dependency_;
491 Node* parameters_node_;
495 explicit Environment(Environment* copy);
496 Environment* Copy() { return new (zone()) Environment(this); }
497 Environment* CopyAndShareLiveness();
498 void UpdateStateValues(Node** state_values, int offset, int count);
499 void UpdateStateValuesWithCache(Node** state_values, int offset, int count);
500 Zone* zone() const { return builder_->local_zone(); }
501 Graph* graph() const { return builder_->graph(); }
502 AstGraphBuilder* builder() const { return builder_; }
503 CommonOperatorBuilder* common() { return builder_->common(); }
504 NodeVector* values() { return &values_; }
505 NodeVector* contexts() { return &contexts_; }
506 LivenessAnalyzerBlock* liveness_block() { return liveness_block_; }
508 // Prepare environment to be used as loop header.
509 void PrepareForLoop(BitVector* assigned, bool is_osr = false);
512 } // namespace compiler
513 } // namespace internal
516 #endif // V8_COMPILER_AST_GRAPH_BUILDER_H_