com.oracle.js.parser.ir.Block Maven / Gradle / Ivy
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package com.oracle.js.parser.ir;
import java.util.List;
import com.oracle.js.parser.ir.visitor.NodeVisitor;
import com.oracle.js.parser.ir.visitor.TranslatorNodeVisitor;
/**
* IR representation for a list of statements.
*/
public class Block extends Node implements BreakableNode, Terminal, Flags, LexicalContextScope {
/** List of statements */
protected final List statements;
protected final Scope scope;
/** Does the block/function need a new scope? Is this synthetic? */
protected final int flags;
/** Flag indicating that this block needs scope */
public static final int NEEDS_SCOPE = 1 << 0;
/**
* Is this block tagged as terminal based on its contents (usually the last statement)
*/
public static final int IS_TERMINAL = 1 << 2;
/**
* Is this block the eager global scope - i.e. the original program. This isn't true for the
* outermost level of recompiles
*/
public static final int IS_GLOBAL_SCOPE = 1 << 3;
/**
* Is this block a synthetic one introduced by Parser?
*/
public static final int IS_SYNTHETIC = 1 << 4;
/**
* Is this the function body block? May not be the first, if parameter list contains
* expressions.
*/
public static final int IS_BODY = 1 << 5;
/**
* Is this the parameter initialization block? If present, must be the first block, immediately
* wrapping the function body block.
*/
public static final int IS_PARAMETER_BLOCK = 1 << 6;
/**
* Marks the variable declaration block for case clauses of a switch statement.
*/
public static final int IS_SWITCH_BLOCK = 1 << 7;
/**
* Is this an expression block (class or do expression) that should return its completion value.
*/
public static final int IS_EXPRESSION_BLOCK = 1 << 8;
/**
* Marks the module body block.
*/
public static final int IS_MODULE_BODY = 1 << 9;
/**
* Constructor
*
* @param token The first token of the block
* @param finish The index of the last character
* @param flags The flags of the block
* @param statements All statements in the block
*/
public Block(final long token, final int finish, final int flags, final Scope scope, final List statements) {
super(token, finish);
assert start <= finish;
assert scope.isClosed() : scope;
this.statements = List.copyOf(statements);
this.scope = scope;
final int len = statements.size();
final int terminalFlags = len > 0 && statements.get(len - 1).hasTerminalFlags() ? IS_TERMINAL : 0;
this.flags = terminalFlags | flags;
}
private Block(final Block block, final int finish, final List statements, final int flags) {
super(block, finish);
this.statements = statements;
this.flags = flags;
this.scope = block.scope;
}
/**
* Is this block the outermost eager global scope - i.e. the primordial program? Used for global
* anchor point for scope depth computation for recompilation code
*
* @return true if outermost eager global scope
*/
public boolean isGlobalScope() {
return getFlag(IS_GLOBAL_SCOPE);
}
/**
* Assist in IR navigation.
*
* @param visitor IR navigating visitor.
* @return new or same node
*/
@Override
public Node accept(final LexicalContext lc, final NodeVisitor visitor) {
if (visitor.enterBlock(this)) {
return visitor.leaveBlock(setStatements(lc, Node.accept(visitor, statements)));
}
return this;
}
@Override
public R accept(LexicalContext lc, TranslatorNodeVisitor visitor) {
return visitor.enterBlock(this);
}
/**
* Get all the symbols defined in this block, in definition order.
*
* @return symbol iterator
*/
public Iterable getSymbols() {
return scope.getSymbols();
}
/**
* Retrieves an existing symbol defined in the current block.
*
* @param name the name of the symbol
* @return an existing symbol with the specified name defined in the current block, or null if
* this block doesn't define a symbol with this name.
*/
public Symbol getExistingSymbol(final String name) {
return scope.getExistingSymbol(name);
}
/**
* Test if a symbol with this name is defined in the current block.
*
* @param name the name of the symbol
*/
public boolean hasSymbol(final String name) {
return scope.hasSymbol(name);
}
/**
* Get the number of symbols defined in this block.
*/
public int getSymbolCount() {
return scope.getSymbolCount();
}
/**
* Test if this block represents a catch block in a try statement.
*
* @return true if this block represents a catch block in a try statement.
*/
public boolean isCatchBlock() {
return getLastStatement() instanceof CatchNode;
}
@Override
public void toString(final StringBuilder sb, final boolean printType) {
for (final Node statement : statements) {
statement.toString(sb, printType);
sb.append(';');
}
}
@Override
public int getFlags() {
return flags;
}
/**
* Is this a terminal block, i.e. does it end control flow like ending with a throw or return?
*
* @return true if this node statement is terminal
*/
@Override
public boolean isTerminal() {
return getFlag(IS_TERMINAL);
}
/**
* Get the list of statements in this block
*
* @return a list of statements
*/
public List getStatements() {
return statements;
}
/**
* Returns the number of statements in the block.
*
* @return the number of statements in the block.
*/
public int getStatementCount() {
return statements.size();
}
/**
* Returns the line number of the first statement in the block.
*
* @return the line number of the first statement in the block, or -1 if the block has no
* statements.
*/
public int getFirstStatementLineNumber() {
if (statements.isEmpty()) {
return -1;
}
return statements.get(0).getLineNumber();
}
/**
* Returns the first statement in the block.
*
* @return the first statement in the block, or null if the block has no statements.
*/
public Statement getFirstStatement() {
return statements.isEmpty() ? null : statements.get(0);
}
/**
* Returns the last statement in the block.
*
* @return the last statement in the block, or null if the block has no statements.
*/
public Statement getLastStatement() {
return statements.isEmpty() ? null : statements.get(statements.size() - 1);
}
/**
* Reset the statement list for this block
*
* @param lc lexical context
* @param statements new statement list
* @return new block if statements changed, identity of statements == block.statements
*/
public Block setStatements(final LexicalContext lc, final List statements) {
if (this.statements == statements) {
return this;
}
int lastFinish = 0;
if (!statements.isEmpty()) {
lastFinish = statements.get(statements.size() - 1).getFinish();
}
return Node.replaceInLexicalContext(lc, this, new Block(this, Math.max(finish, lastFinish), statements, flags));
}
/**
* Check whether scope is necessary for this Block
*
* @return true if this function needs a scope
*/
public boolean needsScope() {
return (flags & NEEDS_SCOPE) == NEEDS_SCOPE;
}
/**
* Check whether this block is synthetic or not.
*
* @return true if this is a synthetic block
*/
public boolean isSynthetic() {
return (flags & IS_SYNTHETIC) == IS_SYNTHETIC;
}
@Override
public Block setFlags(final LexicalContext lc, final int flags) {
if (this.flags == flags) {
return this;
}
return Node.replaceInLexicalContext(lc, this, new Block(this, finish, statements, flags));
}
@Override
public Block setFlag(final LexicalContext lc, final int flag) {
return setFlags(lc, flags | flag);
}
@Override
public boolean getFlag(final int flag) {
return (flags & flag) == flag;
}
@Override
public boolean isBreakableWithoutLabel() {
return false;
}
@Override
public Node accept(final NodeVisitor visitor) {
return BreakableNode.super.accept(visitor);
}
@Override
public R accept(TranslatorNodeVisitor visitor) {
return BreakableNode.super.accept(visitor);
}
@Override
public Scope getScope() {
return scope;
}
public boolean isFunctionBody() {
return getFlag(IS_BODY);
}
public boolean isParameterBlock() {
return getFlag(IS_PARAMETER_BLOCK);
}
public boolean isSwitchBlock() {
return getFlag(IS_SWITCH_BLOCK);
}
public boolean isExpressionBlock() {
return getFlag(IS_EXPRESSION_BLOCK);
}
public boolean isModuleBody() {
return getFlag(IS_MODULE_BODY);
}
}
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