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// Copyright 2006-2009 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_FUNC_NAME_INFERRER_H_
#define V8_FUNC_NAME_INFERRER_H_
#include "src/handles.h"
#include "src/zone.h"
namespace v8 {
namespace internal {
class AstRawString;
class AstString;
class AstValueFactory;
class FunctionLiteral;
// FuncNameInferrer is a stateful class that is used to perform name
// inference for anonymous functions during static analysis of source code.
// Inference is performed in cases when an anonymous function is assigned
// to a variable or a property (see test-func-name-inference.cc for examples.)
//
// The basic idea is that during parsing of LHSs of certain expressions
// (assignments, declarations, object literals) we collect name strings,
// and during parsing of the RHS, a function literal can be collected. After
// parsing the RHS we can infer a name for function literals that do not have
// a name.
class FuncNameInferrer : public ZoneObject {
public:
FuncNameInferrer(AstValueFactory* ast_value_factory, Zone* zone);
// To enter function name inference state, put a FuncNameInferrer::State
// on the stack.
class State {
public:
explicit State(FuncNameInferrer* fni) : fni_(fni) {
if (fni_ != nullptr) fni_->Enter();
}
~State() {
if (fni_ != nullptr) fni_->Leave();
}
private:
FuncNameInferrer* fni_;
DISALLOW_COPY_AND_ASSIGN(State);
};
// Returns whether we have entered name collection state.
bool IsOpen() const { return !entries_stack_.is_empty(); }
// Pushes an enclosing the name of enclosing function onto names stack.
void PushEnclosingName(const AstRawString* name);
// Pushes an encountered name onto names stack when in collection state.
void PushLiteralName(const AstRawString* name);
void PushVariableName(const AstRawString* name);
// Adds a function to infer name for.
void AddFunction(FunctionLiteral* func_to_infer) {
if (IsOpen()) {
funcs_to_infer_.Add(func_to_infer, zone());
}
}
void RemoveLastFunction() {
if (IsOpen() && !funcs_to_infer_.is_empty()) {
funcs_to_infer_.RemoveLast();
}
}
// Infers a function name and leaves names collection state.
void Infer() {
DCHECK(IsOpen());
if (!funcs_to_infer_.is_empty()) {
InferFunctionsNames();
}
}
private:
enum NameType {
kEnclosingConstructorName,
kLiteralName,
kVariableName
};
struct Name {
Name(const AstRawString* name, NameType type) : name(name), type(type) {}
const AstRawString* name;
NameType type;
};
void Enter() { entries_stack_.Add(names_stack_.length(), zone()); }
void Leave() {
DCHECK(IsOpen());
names_stack_.Rewind(entries_stack_.RemoveLast());
if (entries_stack_.is_empty()) funcs_to_infer_.Clear();
}
Zone* zone() const { return zone_; }
// Constructs a full name in dotted notation from gathered names.
const AstString* MakeNameFromStack();
// A helper function for MakeNameFromStack.
const AstString* MakeNameFromStackHelper(int pos,
const AstString* prev);
// Performs name inferring for added functions.
void InferFunctionsNames();
AstValueFactory* ast_value_factory_;
ZoneList<int> entries_stack_;
ZoneList<Name> names_stack_;
ZoneList<FunctionLiteral*> funcs_to_infer_;
Zone* zone_;
DISALLOW_COPY_AND_ASSIGN(FuncNameInferrer);
};
} // namespace internal
} // namespace v8
#endif // V8_FUNC_NAME_INFERRER_H_
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