/**
* Copyright (c) 2012-2016 André Bargull
* Alle Rechte vorbehalten / All Rights Reserved. Use is subject to license terms.
*
* <https://github.com/anba/es6draft>
*/
package com.github.anba.es6draft.compiler;
import static com.github.anba.es6draft.semantics.StaticSemantics.*;
import java.util.ArrayDeque;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import com.github.anba.es6draft.ast.Declaration;
import com.github.anba.es6draft.ast.FunctionDeclaration;
import com.github.anba.es6draft.ast.HoistableDeclaration;
import com.github.anba.es6draft.ast.Script;
import com.github.anba.es6draft.ast.StatementListItem;
import com.github.anba.es6draft.ast.VariableDeclaration;
import com.github.anba.es6draft.ast.VariableStatement;
import com.github.anba.es6draft.ast.scope.Name;
import com.github.anba.es6draft.compiler.CodeGenerator.ScriptName;
import com.github.anba.es6draft.compiler.assembler.Code.MethodCode;
import com.github.anba.es6draft.compiler.assembler.Jump;
import com.github.anba.es6draft.compiler.assembler.Variable;
import com.github.anba.es6draft.runtime.ExecutionContext;
import com.github.anba.es6draft.runtime.GlobalEnvironmentRecord;
import com.github.anba.es6draft.runtime.LexicalEnvironment;
import com.github.anba.es6draft.runtime.types.builtins.FunctionObject;
/**
* <h1>15 ECMAScript Language: Scripts and Modules</h1><br>
* <h2>15.1 Scripts</h2>
* <ul>
* <li>15.1.8 Runtime Semantics: GlobalDeclarationInstantiation (script, env)
* </ul>
*/
final class GlobalDeclarationInstantiationGenerator extends DeclarationBindingInstantiationGenerator {
private static final int EXECUTION_CONTEXT = 0;
private static final class GlobalDeclInitMethodGenerator extends InstructionVisitor {
GlobalDeclInitMethodGenerator(MethodCode method) {
super(method);
}
@Override
public void begin() {
super.begin();
setParameterName("cx", EXECUTION_CONTEXT, Types.ExecutionContext);
}
}
GlobalDeclarationInstantiationGenerator(CodeGenerator codegen) {
super(codegen);
}
void generate(Script script) {
MethodCode method = codegen.newMethod(script, ScriptName.Init);
InstructionVisitor mv = new GlobalDeclInitMethodGenerator(method);
mv.lineInfo(script);
mv.begin();
if (VarDeclaredNames(script).isEmpty() && LexicallyDeclaredNames(script).isEmpty()
&& !hasBlockFunctions(script)) {
mv._return();
} else {
generate(script, mv);
}
mv.end();
}
private void generate(Script script, InstructionVisitor mv) {
Variable<ExecutionContext> context = mv.getParameter(EXECUTION_CONTEXT,
ExecutionContext.class);
Variable<LexicalEnvironment<GlobalEnvironmentRecord>> env = mv.newVariable("globalEnv",
LexicalEnvironment.class).uncheckedCast();
Variable<GlobalEnvironmentRecord> envRec = mv.newVariable("envRec",
GlobalEnvironmentRecord.class);
Variable<FunctionObject> fo = null;
/* steps 1-2 */
getLexicalEnvironment(context, env, mv);
getEnvironmentRecord(env, envRec, mv);
/* step 3 */
HashSet<Name> lexNames = new HashSet<>();
/* step 4 */
HashSet<Name> varNames = new HashSet<>();
/* step 5 */
// Iterate over declarations to be able to emit line-info entries.
for (Declaration d : LexicallyScopedDeclarations(script)) {
assert !(d instanceof HoistableDeclaration);
for (Name name : BoundNames(d)) {
if (lexNames.add(name)) {
canDeclareLexicalScopedOrThrow(context, envRec, d, name, mv);
}
}
}
/* step 6 */
// Iterate over declarations to be able to emit line-info entries.
for (StatementListItem item : VarScopedDeclarations(script)) {
if (item instanceof VariableStatement) {
for (VariableDeclaration vd : ((VariableStatement) item).getElements()) {
for (Name name : BoundNames(vd)) {
if (varNames.add(name)) {
canDeclareVarScopedOrThrow(context, envRec, vd, name, mv);
}
}
}
} else {
HoistableDeclaration d = (HoistableDeclaration) item;
Name name = BoundName(d);
if (varNames.add(name)) {
canDeclareVarScopedOrThrow(context, envRec, d, name, mv);
}
}
}
/* step 7 */
List<StatementListItem> varDeclarations = VarScopedDeclarations(script);
/* step 8 */
ArrayDeque<HoistableDeclaration> functionsToInitialize = new ArrayDeque<>();
/* step 9 */
HashSet<Name> declaredFunctionNames = new HashSet<>();
/* step 10 */
for (StatementListItem item : reverse(varDeclarations)) {
if (item instanceof HoistableDeclaration) {
HoistableDeclaration d = (HoistableDeclaration) item;
Name fn = BoundName(d);
if (declaredFunctionNames.add(fn)) {
canDeclareGlobalFunctionOrThrow(context, envRec, d, fn, mv);
functionsToInitialize.addFirst(d);
}
}
}
if (!functionsToInitialize.isEmpty()) {
fo = mv.newVariable("fo", FunctionObject.class);
}
/* step 11 */
LinkedHashMap<Name, VariableDeclaration> declaredVarNames = new LinkedHashMap<>();
/* step 12 */
for (StatementListItem d : varDeclarations) {
if (d instanceof VariableStatement) {
for (VariableDeclaration vd : ((VariableStatement) d).getElements()) {
for (Name vn : BoundNames(vd)) {
if (!declaredFunctionNames.contains(vn)) {
canDeclareGlobalVarOrThrow(context, envRec, vd, vn, mv);
declaredVarNames.put(vn, vd);
}
}
}
}
}
/* step 13 (note) */
// ES2016: Block-scoped global function declarations
if (hasBlockFunctions(script)) {
int idCounter = 0;
HashSet<Name> declaredFunctionOrVarNames = new HashSet<>();
declaredFunctionOrVarNames.addAll(declaredFunctionNames);
declaredFunctionOrVarNames.addAll(declaredVarNames.keySet());
for (FunctionDeclaration f : script.getScope().blockFunctions()) {
Name fn = BoundName(f);
Jump next = new Jump();
// Runtime check always required for global block-level function declarations.
f.setLegacyBlockScopeId(++idCounter);
// FIXME: spec issue - avoid (observable!) duplicate checks for same name?
// FIXME: spec issue - property creation order important?
canDeclareGlobalFunction(envRec, f, fn, next, mv);
setLegacyBlockFunction(context, f, mv);
if (declaredFunctionOrVarNames.add(fn)) {
createGlobalFunctionBinding(envRec, f, fn, false, mv);
}
mv.mark(next);
}
}
/* step 14 */
List<Declaration> lexDeclarations = LexicallyScopedDeclarations(script);
/* step 15 */
for (Declaration d : lexDeclarations) {
assert !(d instanceof HoistableDeclaration);
mv.lineInfo(d);
for (Name dn : BoundNames(d)) {
BindingOp<GlobalEnvironmentRecord> op = BindingOp.of(envRec, dn);
if (d.isConstDeclaration()) {
op.createImmutableBinding(envRec, dn, true, mv);
} else {
op.createMutableBinding(envRec, dn, false, mv);
}
}
}
/* step 16 */
for (HoistableDeclaration f : functionsToInitialize) {
Name fn = BoundName(f);
InstantiateFunctionObject(context, env, f, mv);
mv.store(fo);
createGlobalFunctionBinding(envRec, f, fn, fo, false, mv);
}
/* step 17 */
for (Map.Entry<Name, VariableDeclaration> e : declaredVarNames.entrySet()) {
createGlobalVarBinding(envRec, e.getValue(), e.getKey(), false, mv);
}
/* step 18 */
mv._return();
}
private static boolean hasBlockFunctions(Script script) {
return !script.getScope().blockFunctions().isEmpty();
}
}