Author: [email protected]
Date: Tue Jul 7 02:48:54 2009
New Revision: 2369
Modified:
branches/bleeding_edge/src/parser.cc
branches/bleeding_edge/src/scopes.cc
branches/bleeding_edge/src/scopes.h
branches/bleeding_edge/src/variables.h
Log:
Allow variable proxies for the same global variable to share the same
variable object.
Add a map from names to variables for global scopes just like
non-global scopes. Variables are added to the map by the parser when
it encounters a declaration in a global scope or else at scope
resolution time by a failed variable lookup from the global scope or
an inner one and with no intervening with statements or possible calls
to eval.
Review URL: http://codereview.chromium.org/149245
Modified: branches/bleeding_edge/src/parser.cc
==============================================================================
--- branches/bleeding_edge/src/parser.cc (original)
+++ branches/bleeding_edge/src/parser.cc Tue Jul 7 02:48:54 2009
@@ -1576,10 +1576,10 @@
// to the calling function context.
if (top_scope_->is_function_scope()) {
// Declare the variable in the function scope.
- var = top_scope_->LookupLocal(name);
+ var = top_scope_->LocalLookup(name);
if (var == NULL) {
// Declare the name.
- var = top_scope_->Declare(name, mode);
+ var = top_scope_->DeclareLocal(name, mode);
} else {
// The name was declared before; check for conflicting
// re-declarations. If the previous declaration was a const or the
@@ -3466,8 +3466,8 @@
while (!done) {
Handle<String> param_name = ParseIdentifier(CHECK_OK);
if (!is_pre_parsing_) {
- top_scope_->AddParameter(top_scope_->Declare(param_name,
- Variable::VAR));
+ top_scope_->AddParameter(top_scope_->DeclareLocal(param_name,
+ Variable::VAR));
num_parameters++;
}
done = (peek() == Token::RPAREN);
Modified: branches/bleeding_edge/src/scopes.cc
==============================================================================
--- branches/bleeding_edge/src/scopes.cc (original)
+++ branches/bleeding_edge/src/scopes.cc Tue Jul 7 02:48:54 2009
@@ -71,28 +71,28 @@
// Dummy constructor
-LocalsMap::LocalsMap(bool gotta_love_static_overloading) : HashMap() {}
+VariableMap::VariableMap(bool gotta_love_static_overloading) : HashMap() {}
-LocalsMap::LocalsMap() : HashMap(Match, &LocalsMapAllocator, 8) {}
-LocalsMap::~LocalsMap() {}
+VariableMap::VariableMap() : HashMap(Match, &LocalsMapAllocator, 8) {}
+VariableMap::~VariableMap() {}
-Variable* LocalsMap::Declare(Scope* scope,
- Handle<String> name,
- Variable::Mode mode,
- bool is_valid_LHS,
- Variable::Kind kind) {
+Variable* VariableMap::Declare(Scope* scope,
+ Handle<String> name,
+ Variable::Mode mode,
+ bool is_valid_lhs,
+ Variable::Kind kind) {
HashMap::Entry* p = HashMap::Lookup(name.location(), name->Hash(), true);
if (p->value == NULL) {
// The variable has not been declared yet -> insert it.
ASSERT(p->key == name.location());
- p->value = new Variable(scope, name, mode, is_valid_LHS, kind);
+ p->value = new Variable(scope, name, mode, is_valid_lhs, kind);
}
return reinterpret_cast<Variable*>(p->value);
}
-Variable* LocalsMap::Lookup(Handle<String> name) {
+Variable* VariableMap::Lookup(Handle<String> name) {
HashMap::Entry* p = HashMap::Lookup(name.location(), name->Hash(),
false);
if (p != NULL) {
ASSERT(*reinterpret_cast<String**>(p->key) == *name);
@@ -110,7 +110,7 @@
// Dummy constructor
Scope::Scope()
: inner_scopes_(0),
- locals_(false),
+ variables_(false),
temps_(0),
params_(0),
dynamics_(NULL),
@@ -168,27 +168,26 @@
// instead load them directly from the stack. Currently, the only
// such parameter is 'this' which is passed on the stack when
// invoking scripts
- { Variable* var =
- locals_.Declare(this, Factory::this_symbol(), Variable::VAR,
- false, Variable::THIS);
- var->rewrite_ = new Slot(var, Slot::PARAMETER, -1);
- receiver_ = new VariableProxy(Factory::this_symbol(), true, false);
- receiver_->BindTo(var);
- }
+ Variable* var =
+ variables_.Declare(this, Factory::this_symbol(), Variable::VAR,
+ false, Variable::THIS);
+ var->rewrite_ = new Slot(var, Slot::PARAMETER, -1);
+ receiver_ = new VariableProxy(Factory::this_symbol(), true, false);
+ receiver_->BindTo(var);
if (is_function_scope()) {
// Declare 'arguments' variable which exists in all functions.
- // Note that it may never be accessed, in which case it won't
- // be allocated during variable allocation.
- locals_.Declare(this, Factory::arguments_symbol(), Variable::VAR,
- true, Variable::ARGUMENTS);
+ // Note that it might never be accessed, in which case it won't be
+ // allocated during variable allocation.
+ variables_.Declare(this, Factory::arguments_symbol(), Variable::VAR,
+ true, Variable::ARGUMENTS);
}
}
-Variable* Scope::LookupLocal(Handle<String> name) {
- return locals_.Lookup(name);
+Variable* Scope::LocalLookup(Handle<String> name) {
+ return variables_.Lookup(name);
}
@@ -196,7 +195,7 @@
for (Scope* scope = this;
scope != NULL;
scope = scope->outer_scope()) {
- Variable* var = scope->LookupLocal(name);
+ Variable* var = scope->LocalLookup(name);
if (var != NULL) return var;
}
return NULL;
@@ -210,18 +209,25 @@
}
-Variable* Scope::Declare(Handle<String> name, Variable::Mode mode) {
+Variable* Scope::DeclareLocal(Handle<String> name, Variable::Mode mode) {
// DYNAMIC variables are introduces during variable allocation,
// INTERNAL variables are allocated explicitly, and TEMPORARY
// variables are allocated via NewTemporary().
ASSERT(mode == Variable::VAR || mode == Variable::CONST);
- return locals_.Declare(this, name, mode, true, Variable::NORMAL);
+ return variables_.Declare(this, name, mode, true, Variable::NORMAL);
+}
+
+
+Variable* Scope::DeclareGlobal(Handle<String> name) {
+ ASSERT(is_global_scope());
+ return variables_.Declare(this, name, Variable::DYNAMIC, true,
+ Variable::NORMAL);
}
void Scope::AddParameter(Variable* var) {
ASSERT(is_function_scope());
- ASSERT(LookupLocal(var->name()) == var);
+ ASSERT(LocalLookup(var->name()) == var);
params_.Add(var);
}
@@ -291,7 +297,9 @@
locals->Add(var);
}
}
- for (LocalsMap::Entry* p = locals_.Start(); p != NULL; p =
locals_.Next(p)) {
+ for (VariableMap::Entry* p = variables_.Start();
+ p != NULL;
+ p = variables_.Next(p)) {
Variable* var = reinterpret_cast<Variable*>(p->value);
if (var->var_uses()->is_used()) {
locals->Add(var);
@@ -410,8 +418,8 @@
}
-static void PrintMap(PrettyPrinter* printer, int indent, LocalsMap* map) {
- for (LocalsMap::Entry* p = map->Start(); p != NULL; p = map->Next(p)) {
+static void PrintMap(PrettyPrinter* printer, int indent, VariableMap* map)
{
+ for (VariableMap::Entry* p = map->Start(); p != NULL; p = map->Next(p)) {
Variable* var = reinterpret_cast<Variable*>(p->value);
PrintVar(printer, indent, var);
}
@@ -478,7 +486,7 @@
}
Indent(n1, "// local vars\n");
- PrintMap(&printer, n1, &locals_);
+ PrintMap(&printer, n1, &variables_);
Indent(n1, "// dynamic vars\n");
if (dynamics_ != NULL) {
@@ -502,7 +510,7 @@
Variable* Scope::NonLocal(Handle<String> name, Variable::Mode mode) {
if (dynamics_ == NULL) dynamics_ = new DynamicScopePart();
- LocalsMap* map = dynamics_->GetMap(mode);
+ VariableMap* map = dynamics_->GetMap(mode);
Variable* var = map->Lookup(name);
if (var == NULL) {
// Declare a new non-local.
@@ -530,7 +538,7 @@
bool guess = scope_calls_eval_;
// Try to find the variable in this scope.
- Variable* var = LookupLocal(name);
+ Variable* var = LocalLookup(name);
if (var != NULL) {
// We found a variable. If this is not an inner lookup, we are done.
@@ -621,8 +629,7 @@
scope_calls_eval_ || outer_scope_calls_eval_)) {
// We must have a global variable.
ASSERT(global_scope != NULL);
- var = new Variable(global_scope, proxy->name(),
- Variable::DYNAMIC, true, Variable::NORMAL);
+ var = global_scope->DeclareGlobal(proxy->name());
} else if (scope_inside_with_) {
// If we are inside a with statement we give up and look up
@@ -706,26 +713,26 @@
bool Scope::MustAllocate(Variable* var) {
- // Give var a read/write use if there is a chance it might be
- // accessed via an eval() call, or if it is a global variable.
- // This is only possible if the variable has a visible name.
+ // Give var a read/write use if there is a chance it might be accessed
+ // via an eval() call. This is only possible if the variable has a
+ // visible name.
if ((var->is_this() || var->name()->length() > 0) &&
(var->is_accessed_from_inner_scope_ ||
scope_calls_eval_ || inner_scope_calls_eval_ ||
- scope_contains_with_ || var->is_global())) {
+ scope_contains_with_)) {
var->var_uses()->RecordAccess(1);
}
- return var->var_uses()->is_used();
+ // Global variables do not need to be allocated.
+ return !var->is_global() && var->var_uses()->is_used();
}
bool Scope::MustAllocateInContext(Variable* var) {
// If var is accessed from an inner scope, or if there is a
- // possibility that it might be accessed from the current or
- // an inner scope (through an eval() call), it must be allocated
- // in the context.
- // Exceptions: Global variables and temporary variables must
- // never be allocated in the (FixedArray part of the) context.
+ // possibility that it might be accessed from the current or an inner
+ // scope (through an eval() call), it must be allocated in the
+ // context. Exception: temporary variables are not allocated in the
+ // context.
return
var->mode() != Variable::TEMPORARY &&
(var->is_accessed_from_inner_scope_ ||
@@ -755,7 +762,7 @@
void Scope::AllocateParameterLocals() {
ASSERT(is_function_scope());
- Variable* arguments = LookupLocal(Factory::arguments_symbol());
+ Variable* arguments = LocalLookup(Factory::arguments_symbol());
ASSERT(arguments != NULL); // functions have 'arguments' declared
implicitly
if (MustAllocate(arguments) && !HasArgumentsParameter()) {
// 'arguments' is used. Unless there is also a parameter called
@@ -865,7 +872,7 @@
ASSERT(var->rewrite_ == NULL ||
(!var->IsVariable(Factory::result_symbol())) ||
(var->slot() == NULL || var->slot()->type() != Slot::LOCAL));
- if (MustAllocate(var) && var->rewrite_ == NULL) {
+ if (var->rewrite_ == NULL && MustAllocate(var)) {
if (MustAllocateInContext(var)) {
AllocateHeapSlot(var);
} else {
@@ -876,27 +883,21 @@
void Scope::AllocateNonParameterLocals() {
- // Each variable occurs exactly once in the locals_ list; all
- // variables that have no rewrite yet are non-parameter locals.
-
- // Sort them according to use such that the locals with more uses
- // get allocated first.
- if (FLAG_usage_computation) {
- // This is currently not implemented.
- }
-
+ // All variables that have no rewrite yet are non-parameter locals.
for (int i = 0; i < temps_.length(); i++) {
AllocateNonParameterLocal(temps_[i]);
}
- for (LocalsMap::Entry* p = locals_.Start(); p != NULL; p =
locals_.Next(p)) {
+ for (VariableMap::Entry* p = variables_.Start();
+ p != NULL;
+ p = variables_.Next(p)) {
Variable* var = reinterpret_cast<Variable*>(p->value);
AllocateNonParameterLocal(var);
}
- // Note: For now, function_ must be allocated at the very end. If
- // it gets allocated in the context, it must be the last slot in the
- // context, because of the current ScopeInfo implementation (see
+ // For now, function_ must be allocated at the very end. If it gets
+ // allocated in the context, it must be the last slot in the context,
+ // because of the current ScopeInfo implementation (see
// ScopeInfo::ScopeInfo(FunctionScope* scope) constructor).
if (function_ != NULL) {
AllocateNonParameterLocal(function_);
Modified: branches/bleeding_edge/src/scopes.h
==============================================================================
--- branches/bleeding_edge/src/scopes.h (original)
+++ branches/bleeding_edge/src/scopes.h Tue Jul 7 02:48:54 2009
@@ -35,19 +35,22 @@
namespace internal {
-// A hash map to support fast local variable declaration and lookup.
-class LocalsMap: public HashMap {
+// A hash map to support fast variable declaration and lookup.
+class VariableMap: public HashMap {
public:
- LocalsMap();
+ VariableMap();
// Dummy constructor. This constructor doesn't set up the map
// properly so don't use it unless you have a good reason.
- explicit LocalsMap(bool gotta_love_static_overloading);
+ explicit VariableMap(bool gotta_love_static_overloading);
- virtual ~LocalsMap();
+ virtual ~VariableMap();
- Variable* Declare(Scope* scope, Handle<String> name, Variable::Mode mode,
- bool is_valid_LHS, Variable::Kind kind);
+ Variable* Declare(Scope* scope,
+ Handle<String> name,
+ Variable::Mode mode,
+ bool is_valid_lhs,
+ Variable::Kind kind);
Variable* Lookup(Handle<String> name);
};
@@ -59,14 +62,14 @@
// and setup time for scopes that don't need them.
class DynamicScopePart : public ZoneObject {
public:
- LocalsMap* GetMap(Variable::Mode mode) {
+ VariableMap* GetMap(Variable::Mode mode) {
int index = mode - Variable::DYNAMIC;
ASSERT(index >= 0 && index < 3);
return &maps_[index];
}
private:
- LocalsMap maps_[3];
+ VariableMap maps_[3];
};
@@ -105,7 +108,7 @@
// Declarations
// Lookup a variable in this scope. Returns the variable or NULL if not
found.
- virtual Variable* LookupLocal(Handle<String> name);
+ virtual Variable* LocalLookup(Handle<String> name);
// Lookup a variable in this scope or outer scopes.
// Returns the variable or NULL if not found.
@@ -116,9 +119,15 @@
// outer scope. Only possible for function scopes; at most one variable.
Variable* DeclareFunctionVar(Handle<String> name);
- // Declare a variable in this scope. If the variable has been
+ // Declare a local variable in this scope. If the variable has been
// declared before, the previously declared variable is returned.
- virtual Variable* Declare(Handle<String> name, Variable::Mode mode);
+ virtual Variable* DeclareLocal(Handle<String> name, Variable::Mode mode);
+
+ // Declare an implicit global variable in this scope which must be a
+ // global scope. The variable was introduced (possibly from an inner
+ // scope) by a reference to an unresolved variable with no intervening
+ // with statements or eval calls.
+ Variable* DeclareGlobal(Handle<String> name);
// Add a parameter to the parameter list. The parameter must have been
// declared via Declare. The same parameter may occur more then once in
@@ -288,25 +297,28 @@
Handle<String> scope_name_;
// The variables declared in this scope:
- // all user-declared variables (incl. parameters)
- LocalsMap locals_;
- // compiler-allocated (user-invisible) temporaries
+ //
+ // All user-declared variables (incl. parameters). For global scopes
+ // variables may be implicitly 'declared' by being used (possibly in
+ // an inner scope) with no intervening with statements or eval calls.
+ VariableMap variables_;
+ // Compiler-allocated (user-invisible) temporaries.
ZoneList<Variable*> temps_;
- // parameter list in source order
+ // Parameter list in source order.
ZoneList<Variable*> params_;
- // variables that must be looked up dynamically
+ // Variables that must be looked up dynamically.
DynamicScopePart* dynamics_;
- // unresolved variables referred to from this scope
+ // Unresolved variables referred to from this scope.
ZoneList<VariableProxy*> unresolved_;
- // declarations
+ // Declarations.
ZoneList<Declaration*> decls_;
- // convenience variable
+ // Convenience variable.
VariableProxy* receiver_;
- // function variable, if any; function scopes only
+ // Function variable, if any; function scopes only.
Variable* function_;
- // convenience variable; function scopes only
+ // Convenience variable; function scopes only.
VariableProxy* arguments_;
- // convenience variable; function scopes only
+ // Convenience variable; function scopes only.
VariableProxy* arguments_shadow_;
// Illegal redeclaration.
Modified: branches/bleeding_edge/src/variables.h
==============================================================================
--- branches/bleeding_edge/src/variables.h (original)
+++ branches/bleeding_edge/src/variables.h Tue Jul 7 02:48:54 2009
@@ -143,6 +143,12 @@
ARGUMENTS
};
+ Variable(Scope* scope,
+ Handle<String> name,
+ Mode mode,
+ bool is_valid_lhs,
+ Kind kind);
+
// Printing support
static const char* Mode2String(Mode mode);
@@ -196,9 +202,6 @@
SmiAnalysis* type() { return &type_; }
private:
- Variable(Scope* scope, Handle<String> name, Mode mode, bool is_valid_LHS,
- Kind kind);
-
Scope* scope_;
Handle<String> name_;
Mode mode_;
@@ -216,13 +219,10 @@
SmiAnalysis type_;
// Code generation.
- // rewrite_ is usually a Slot or a Property, but maybe any expression.
+ // rewrite_ is usually a Slot or a Property, but may be any expression.
Expression* rewrite_;
- friend class VariableProxy;
- friend class Scope;
- friend class LocalsMap;
- friend class AstBuildingParser;
+ friend class Scope; // Has explicit access to rewrite_.
};
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