| /* |
| * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package jdk.nashorn.internal.ir; |
| |
| import java.io.PrintWriter; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Collections; |
| import java.util.Comparator; |
| import java.util.LinkedHashMap; |
| import java.util.List; |
| import java.util.Map; |
| import jdk.nashorn.internal.codegen.Label; |
| import jdk.nashorn.internal.ir.annotations.Immutable; |
| import jdk.nashorn.internal.ir.visitor.NodeVisitor; |
| |
| /** |
| * IR representation for a list of statements. |
| */ |
| @Immutable |
| public class Block extends Node implements BreakableNode, Terminal, Flags<Block> { |
| private static final long serialVersionUID = 1L; |
| |
| /** List of statements */ |
| protected final List<Statement> statements; |
| |
| /** Symbol table - keys must be returned in the order they were put in. */ |
| protected final Map<String, Symbol> symbols; |
| |
| /** Entry label. */ |
| private final Label entryLabel; |
| |
| /** Break label. */ |
| private final Label breakLabel; |
| |
| /** Does the block/function need a new scope? */ |
| protected final int flags; |
| |
| /** |
| * @see JoinPredecessor |
| */ |
| private final LocalVariableConversion conversion; |
| |
| /** 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; |
| |
| /** |
| * Constructor |
| * |
| * @param token token |
| * @param finish finish |
| * @param statements statements |
| */ |
| public Block(final long token, final int finish, final Statement... statements) { |
| super(token, finish); |
| |
| this.statements = Arrays.asList(statements); |
| this.symbols = new LinkedHashMap<>(); |
| this.entryLabel = new Label("block_entry"); |
| this.breakLabel = new Label("block_break"); |
| final int len = statements.length; |
| this.flags = len > 0 && statements[len - 1].hasTerminalFlags() ? IS_TERMINAL : 0; |
| this.conversion = null; |
| } |
| |
| /** |
| * Constructor |
| * |
| * @param token token |
| * @param finish finish |
| * @param statements statements |
| */ |
| public Block(final long token, final int finish, final List<Statement> statements) { |
| this(token, finish, statements.toArray(new Statement[statements.size()])); |
| } |
| |
| private Block(final Block block, final int finish, final List<Statement> statements, final int flags, final Map<String, Symbol> symbols, final LocalVariableConversion conversion) { |
| super(block); |
| this.statements = statements; |
| this.flags = flags; |
| this.symbols = new LinkedHashMap<>(symbols); //todo - symbols have no dependencies on any IR node and can as far as we understand it be shallow copied now |
| this.entryLabel = new Label(block.entryLabel); |
| this.breakLabel = new Label(block.breakLabel); |
| this.finish = finish; |
| this.conversion = conversion; |
| } |
| |
| /** |
| * 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); |
| } |
| |
| /** |
| * Returns true if this block defines any symbols. |
| * @return true if this block defines any symbols. |
| */ |
| public boolean hasSymbols() { |
| return !symbols.isEmpty(); |
| } |
| |
| /** |
| * Replaces symbols defined in this block with different symbols. Used to ensure symbol tables are |
| * immutable upon construction and have copy-on-write semantics. Note that this method only replaces the |
| * symbols in the symbol table, it does not act on any contained AST nodes that might reference the symbols. |
| * Those should be updated separately as this method is meant to be used as part of such an update pass. |
| * @param lc the current lexical context |
| * @param replacements the map of symbol replacements |
| * @return a new block with replaced symbols, or this block if none of the replacements modified the symbol |
| * table. |
| */ |
| public Block replaceSymbols(final LexicalContext lc, final Map<Symbol, Symbol> replacements) { |
| if (symbols.isEmpty()) { |
| return this; |
| } |
| final LinkedHashMap<String, Symbol> newSymbols = new LinkedHashMap<>(symbols); |
| for (final Map.Entry<String, Symbol> entry: newSymbols.entrySet()) { |
| final Symbol newSymbol = replacements.get(entry.getValue()); |
| assert newSymbol != null : "Missing replacement for " + entry.getKey(); |
| entry.setValue(newSymbol); |
| } |
| return Node.replaceInLexicalContext(lc, this, new Block(this, finish, statements, flags, newSymbols, conversion)); |
| } |
| |
| /** |
| * Returns a copy of this block with a shallow copy of the symbol table. |
| * @return a copy of this block with a shallow copy of the symbol table. |
| */ |
| public Block copyWithNewSymbols() { |
| return new Block(this, finish, statements, flags, new LinkedHashMap<>(symbols), conversion); |
| } |
| |
| @Override |
| public Node ensureUniqueLabels(final LexicalContext lc) { |
| return Node.replaceInLexicalContext(lc, this, new Block(this, finish, statements, flags, symbols, conversion)); |
| } |
| |
| /** |
| * Assist in IR navigation. |
| * |
| * @param visitor IR navigating visitor. |
| * @return new or same node |
| */ |
| @Override |
| public Node accept(final LexicalContext lc, final NodeVisitor<? extends LexicalContext> visitor) { |
| if (visitor.enterBlock(this)) { |
| return visitor.leaveBlock(setStatements(lc, Node.accept(visitor, statements))); |
| } |
| |
| return this; |
| } |
| |
| /** |
| * Get a copy of the list for all the symbols defined in this block |
| * @return symbol iterator |
| */ |
| public List<Symbol> getSymbols() { |
| return symbols.isEmpty() ? Collections.<Symbol>emptyList() : Collections.unmodifiableList(new ArrayList<>(symbols.values())); |
| } |
| |
| /** |
| * 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.T |
| */ |
| public Symbol getExistingSymbol(final String name) { |
| return symbols.get(name); |
| } |
| |
| /** |
| * Test if this block represents a <tt>catch</tt> block in a <tt>try</tt> statement. |
| * This is used by the Splitter as catch blocks are not be subject to splitting. |
| * |
| * @return true if this block represents a catch block in a try statement. |
| */ |
| public boolean isCatchBlock() { |
| return statements.size() == 1 && statements.get(0) instanceof CatchNode; |
| } |
| |
| @Override |
| public void toString(final StringBuilder sb, final boolean printType) { |
| for (final Node statement : statements) { |
| statement.toString(sb, printType); |
| sb.append(';'); |
| } |
| } |
| |
| /** |
| * Print symbols in block in alphabetical order, sorted on name |
| * Used for debugging, see the --print-symbols flag |
| * |
| * @param stream print writer to output symbols to |
| * |
| * @return true if symbols were found |
| */ |
| public boolean printSymbols(final PrintWriter stream) { |
| final List<Symbol> values = new ArrayList<>(symbols.values()); |
| |
| Collections.sort(values, new Comparator<Symbol>() { |
| @Override |
| public int compare(final Symbol s0, final Symbol s1) { |
| return s0.getName().compareTo(s1.getName()); |
| } |
| }); |
| |
| for (final Symbol symbol : values) { |
| symbol.print(stream); |
| } |
| |
| return !values.isEmpty(); |
| } |
| |
| /** |
| * Tag block as terminal or non terminal |
| * @param lc lexical context |
| * @param isTerminal is block terminal |
| * @return same block, or new if flag changed |
| */ |
| public Block setIsTerminal(final LexicalContext lc, final boolean isTerminal) { |
| return isTerminal ? setFlag(lc, IS_TERMINAL) : clearFlag(lc, IS_TERMINAL); |
| } |
| |
| @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 entry label for this block |
| * @return the entry label |
| */ |
| public Label getEntryLabel() { |
| return entryLabel; |
| } |
| |
| @Override |
| public Label getBreakLabel() { |
| return breakLabel; |
| } |
| |
| @Override |
| public Block setLocalVariableConversion(final LexicalContext lc, final LocalVariableConversion conversion) { |
| if(this.conversion == conversion) { |
| return this; |
| } |
| return Node.replaceInLexicalContext(lc, this, new Block(this, finish, statements, flags, symbols, conversion)); |
| } |
| |
| @Override |
| public LocalVariableConversion getLocalVariableConversion() { |
| return conversion; |
| } |
| |
| /** |
| * Get the list of statements in this block |
| * |
| * @return a list of statements |
| */ |
| public List<Statement> getStatements() { |
| return Collections.unmodifiableList(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 == null || statements.isEmpty()) { |
| return -1; |
| } |
| return statements.get(0).getLineNumber(); |
| } |
| |
| /** |
| * 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<Statement> 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, symbols, conversion)); |
| } |
| |
| /** |
| * Add or overwrite an existing symbol in the block |
| * |
| * @param symbol symbol |
| */ |
| public void putSymbol(final Symbol symbol) { |
| symbols.put(symbol.getName(), symbol); |
| } |
| |
| /** |
| * 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; |
| } |
| |
| @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, symbols, conversion)); |
| } |
| |
| @Override |
| public Block clearFlag(final LexicalContext lc, final int flag) { |
| return setFlags(lc, flags & ~flag); |
| } |
| |
| @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; |
| } |
| |
| /** |
| * Set the needs scope flag. |
| * @param lc lexicalContext |
| * @return new block if state changed, otherwise this |
| */ |
| public Block setNeedsScope(final LexicalContext lc) { |
| if (needsScope()) { |
| return this; |
| } |
| |
| return Node.replaceInLexicalContext(lc, this, new Block(this, finish, statements, flags | NEEDS_SCOPE, symbols, conversion)); |
| } |
| |
| /** |
| * Computationally determine the next slot for this block, |
| * indexed from 0. Use this as a relative base when computing |
| * frames |
| * @return next slot |
| */ |
| public int nextSlot() { |
| int next = 0; |
| for (final Symbol symbol : getSymbols()) { |
| if (symbol.hasSlot()) { |
| next += symbol.slotCount(); |
| } |
| } |
| return next; |
| } |
| |
| @Override |
| public boolean isBreakableWithoutLabel() { |
| return false; |
| } |
| |
| @Override |
| public List<Label> getLabels() { |
| return Collections.unmodifiableList(Arrays.asList(entryLabel, breakLabel)); |
| } |
| |
| @Override |
| public Node accept(final NodeVisitor<? extends LexicalContext> visitor) { |
| return Acceptor.accept(this, visitor); |
| } |
| } |