/*
***** BEGIN LICENSE BLOCK *****
* Version: CPL 1.0/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Common Public
* License Version 1.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.eclipse.org/legal/cpl-v10.html
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* Copyright (C) 2007 Charles O Nutter <headius@headius.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the CPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the CPL, the GPL or the LGPL.
***** END LICENSE BLOCK *****/
package org.jruby.compiler;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
import org.jruby.ast.AndNode;
import org.jruby.ast.ArgsCatNode;
import org.jruby.ast.ArgsNode;
import org.jruby.ast.ArgsPushNode;
import org.jruby.ast.AssignableNode;
import org.jruby.ast.AttrAssignNode;
import org.jruby.ast.BeginNode;
import org.jruby.ast.BinaryOperatorNode;
import org.jruby.ast.BlockAcceptingNode;
import org.jruby.ast.BlockNode;
import org.jruby.ast.BlockPassNode;
import org.jruby.ast.BreakNode;
import org.jruby.ast.CallNode;
import org.jruby.ast.CaseNode;
import org.jruby.ast.Colon2Node;
import org.jruby.ast.ConstNode;
import org.jruby.ast.DotNode;
import org.jruby.ast.EvStrNode;
import org.jruby.ast.FlipNode;
import org.jruby.ast.ForNode;
import org.jruby.ast.GlobalAsgnNode;
import org.jruby.ast.GlobalVarNode;
import org.jruby.ast.HashNode;
import org.jruby.ast.IArgumentNode;
import org.jruby.ast.IScopingNode;
import org.jruby.ast.IfNode;
import org.jruby.ast.ListNode;
import org.jruby.ast.LocalAsgnNode;
import org.jruby.ast.Match2Node;
import org.jruby.ast.Match3Node;
import org.jruby.ast.MatchNode;
import org.jruby.ast.MultipleAsgnNode;
import org.jruby.ast.NewlineNode;
import org.jruby.ast.NextNode;
import org.jruby.ast.Node;
import org.jruby.ast.NotNode;
import org.jruby.ast.OpAsgnAndNode;
import org.jruby.ast.OpAsgnNode;
import org.jruby.ast.OpElementAsgnNode;
import org.jruby.ast.OrNode;
import org.jruby.ast.PostExeNode;
import org.jruby.ast.PreExeNode;
import org.jruby.ast.ReturnNode;
import org.jruby.ast.RootNode;
import org.jruby.ast.SValueNode;
import org.jruby.ast.SplatNode;
import org.jruby.ast.SuperNode;
import org.jruby.ast.ToAryNode;
import org.jruby.ast.TrueNode;
import org.jruby.ast.UntilNode;
import org.jruby.ast.WhenNode;
import org.jruby.ast.WhileNode;
import org.jruby.ast.YieldNode;
import org.jruby.ast.ZSuperNode;
import org.jruby.ast.types.INameNode;
import org.jruby.util.SafePropertyAccessor;
/**
*
* @author headius
*/
public class ASTInspector {
public static final int BLOCK_ARG = 0x1; // block argument to the method
public static final int CLOSURE = 0x2; // closure present
public static final int CLASS = 0x4; // class present
public static final int METHOD = 0x8; // method table mutations, def, defs, undef, alias
public static final int EVAL = 0x10; // likely call to eval
public static final int FRAME_AWARE = 0x20; // makes calls that are aware of the frame
public static final int FRAME_SELF = 0x40; // makes calls that are aware of the frame's self
public static final int FRAME_VISIBILITY = 0x80; // makes calls that are aware of the frame's visibility
public static final int FRAME_BLOCK = 0x100; // makes calls that are aware of the frame's block
public static final int FRAME_NAME = 0x200; // makes calls that are aware of the frame's name
public static final int BACKREF = 0x400; // makes calls that set or get backref
public static final int LASTLINE = 0x800; // makes calls that set or get lastline
public static final int FRAME_CLASS = 0x1000; // makes calls that are aware of the frame's class
public static final int OPT_ARGS = 0x2000; // optional arguments to the method
public static final int REST_ARG = 0x4000; // rest arg to the method
public static final int SCOPE_AWARE = 0x8000; // makes calls that are aware of the scope
public static final int ZSUPER = 0x10000; // makes a zero-argument super call
public static final int CONSTANT = 0x20000; // accesses or sets constants
public static final int CLASS_VAR = 0x40000; // accesses or sets class variables
private int flags;
// pragmas
private boolean noFrame;
public static Set<String> FRAME_AWARE_METHODS = Collections.synchronizedSet(new HashSet<String>());
private static Set<String> SCOPE_AWARE_METHODS = Collections.synchronizedSet(new HashSet<String>());
public static Set<String> PRAGMAS = Collections.synchronizedSet(new HashSet<String>());
static {
FRAME_AWARE_METHODS.add("eval");
FRAME_AWARE_METHODS.add("module_eval");
FRAME_AWARE_METHODS.add("class_eval");
FRAME_AWARE_METHODS.add("instance_eval");
FRAME_AWARE_METHODS.add("binding");
FRAME_AWARE_METHODS.add("public");
FRAME_AWARE_METHODS.add("private");
FRAME_AWARE_METHODS.add("protected");
FRAME_AWARE_METHODS.add("module_function");
FRAME_AWARE_METHODS.add("block_given?");
FRAME_AWARE_METHODS.add("iterator?");
SCOPE_AWARE_METHODS.add("eval");
SCOPE_AWARE_METHODS.add("module_eval");
SCOPE_AWARE_METHODS.add("class_eval");
SCOPE_AWARE_METHODS.add("instance_eval");
SCOPE_AWARE_METHODS.add("binding");
SCOPE_AWARE_METHODS.add("local_variables");
PRAGMAS.add("__NOFRAME__");
}
public void disable() {
flags = 0xFFFFFFFF;
}
public static final boolean ENABLED = SafePropertyAccessor.getProperty("jruby.astInspector.enabled", "true").equals("true");
/**
* Perform an inspection of a subtree or set of subtrees separate from the
* parent inspection, to make independent decisions based on that subtree(s).
*
* @param nodes The child nodes to walk with a new inspector
* @return The new inspector resulting from the walk
*/
public static ASTInspector subInspect(Node... nodes) {
ASTInspector newInspector = new ASTInspector();
for (Node node : nodes) {
newInspector.inspect(node);
}
return newInspector;
}
public boolean getFlag(int modifier) {
return (flags & modifier) != 0;
}
public void setFlag(int modifier) {
flags |= modifier;
}
/**
* Integrate the results of a separate inspection into the state of this
* inspector.
*
* @param other The other inspector whose state to integrate.
*/
public void integrate(ASTInspector other) {
flags |= other.flags;
}
public void inspect(Node node) {
// TODO: This code effectively disables all inspection-based optimizations; none of them are 100% safe yet
if (!ENABLED) disable();
if (node == null) return;
switch (node.nodeId) {
case ALIASNODE:
setFlag(METHOD);
break;
case ANDNODE:
AndNode andNode = (AndNode)node;
inspect(andNode.getFirstNode());
inspect(andNode.getSecondNode());
break;
case ARGSCATNODE:
ArgsCatNode argsCatNode = (ArgsCatNode)node;
inspect(argsCatNode.getFirstNode());
inspect(argsCatNode.getSecondNode());
break;
case ARGSPUSHNODE:
ArgsPushNode argsPushNode = (ArgsPushNode)node;
inspect(argsPushNode.getFirstNode());
inspect(argsPushNode.getSecondNode());
break;
case ARGUMENTNODE:
break;
case ARRAYNODE:
case BLOCKNODE:
case DREGEXPNODE:
case DSTRNODE:
case DSYMBOLNODE:
case DXSTRNODE:
case LISTNODE:
ListNode listNode = (ListNode)node;
for (int i = 0; i < listNode.size(); i++) {
inspect(listNode.get(i));
}
break;
case ARGSNODE:
ArgsNode argsNode = (ArgsNode)node;
if (argsNode.getBlockArgNode() != null) setFlag(BLOCK_ARG);
if (argsNode.getOptArgs() != null) {
setFlag(OPT_ARGS);
inspect(argsNode.getOptArgs());
}
if (argsNode.getRestArg() == -2 || argsNode.getRestArg() >= 0) setFlag(REST_ARG);
break;
case ATTRASSIGNNODE:
AttrAssignNode attrAssignNode = (AttrAssignNode)node;
setFlag(FRAME_SELF);
inspect(attrAssignNode.getArgsNode());
inspect(attrAssignNode.getReceiverNode());
break;
case BACKREFNODE:
setFlag(BACKREF);
break;
case BEGINNODE:
inspect(((BeginNode)node).getBodyNode());
break;
case BIGNUMNODE:
break;
case BINARYOPERATORNODE:
BinaryOperatorNode binaryOperatorNode = (BinaryOperatorNode)node;
inspect(binaryOperatorNode.getFirstNode());
inspect(binaryOperatorNode.getSecondNode());
break;
case BLOCKARGNODE:
break;
case BLOCKPASSNODE:
BlockPassNode blockPassNode = (BlockPassNode)node;
inspect(blockPassNode.getArgsNode());
inspect(blockPassNode.getBodyNode());
break;
case BREAKNODE:
inspect(((BreakNode)node).getValueNode());
break;
case CALLNODE:
CallNode callNode = (CallNode)node;
inspect(callNode.getReceiverNode());
// check for Proc.new, an especially magic method
if (callNode.getName() == "new" &&
callNode.getReceiverNode() instanceof ConstNode &&
((ConstNode)callNode.getReceiverNode()).getName() == "Proc") {
// Proc.new needs the caller's block to instantiate a proc
setFlag(FRAME_BLOCK);
}
case FCALLNODE:
inspect(((IArgumentNode)node).getArgsNode());
inspect(((BlockAcceptingNode)node).getIterNode());
case VCALLNODE:
INameNode nameNode = (INameNode)node;
if (FRAME_AWARE_METHODS.contains(nameNode.getName())) {
setFlag(FRAME_AWARE);
if (nameNode.getName().indexOf("eval") != -1) {
setFlag(EVAL);
}
}
if (SCOPE_AWARE_METHODS.contains(nameNode.getName())) {
setFlag(SCOPE_AWARE);
}
break;
case CASENODE:
CaseNode caseNode = (CaseNode)node;
inspect(caseNode.getCaseNode());
inspect(caseNode.getFirstWhenNode());
break;
case CLASSNODE:
setFlag(CLASS);
break;
case CLASSVARNODE:
setFlag(CLASS_VAR);
break;
case CONSTDECLNODE:
inspect(((AssignableNode)node).getValueNode());
setFlag(CONSTANT);
break;
case CLASSVARASGNNODE:
inspect(((AssignableNode)node).getValueNode());
setFlag(CLASS_VAR);
break;
case CLASSVARDECLNODE:
inspect(((AssignableNode)node).getValueNode());
setFlag(CLASS_VAR);
break;
case COLON2NODE:
inspect(((Colon2Node)node).getLeftNode());
break;
case COLON3NODE:
break;
case CONSTNODE:
setFlag(CONSTANT);
break;
case DEFNNODE:
case DEFSNODE:
setFlag(METHOD);
setFlag(FRAME_VISIBILITY);
break;
case DEFINEDNODE:
disable();
break;
case DOTNODE:
DotNode dotNode = (DotNode)node;
inspect(dotNode.getBeginNode());
inspect(dotNode.getEndNode());
break;
case DASGNNODE:
inspect(((AssignableNode)node).getValueNode());
break;
case DVARNODE:
break;
case ENSURENODE:
disable();
break;
case EVSTRNODE:
inspect(((EvStrNode)node).getBody());
break;
case FALSENODE:
break;
case FIXNUMNODE:
break;
case FLIPNODE:
inspect(((FlipNode)node).getBeginNode());
inspect(((FlipNode)node).getEndNode());
break;
case FLOATNODE:
break;
case FORNODE:
setFlag(CLOSURE);
setFlag(SCOPE_AWARE);
inspect(((ForNode)node).getIterNode());
inspect(((ForNode)node).getBodyNode());
inspect(((ForNode)node).getVarNode());
break;
case GLOBALASGNNODE:
GlobalAsgnNode globalAsgnNode = (GlobalAsgnNode)node;
if (globalAsgnNode.getName().equals("$_")) {
setFlag(LASTLINE);
} else if (globalAsgnNode.getName().equals("$~")) {
setFlag(BACKREF);
}
break;
case GLOBALVARNODE:
if (((GlobalVarNode)node).getName().equals("$_")) {
setFlag(LASTLINE);
} else if (((GlobalVarNode)node).getName().equals("$~")) {
setFlag(BACKREF);
}
break;
case HASHNODE:
HashNode hashNode = (HashNode)node;
inspect(hashNode.getListNode());
break;
case IFNODE:
IfNode ifNode = (IfNode)node;
inspect(ifNode.getCondition());
inspect(ifNode.getThenBody());
inspect(ifNode.getElseBody());
break;
case INSTASGNNODE:
inspect(((AssignableNode)node).getValueNode());
break;
case INSTVARNODE:
break;
case ISCOPINGNODE:
IScopingNode iscopingNode = (IScopingNode)node;
inspect(iscopingNode.getCPath());
break;
case ITERNODE:
setFlag(CLOSURE);
break;
case LOCALASGNNODE:
LocalAsgnNode localAsgnNode = (LocalAsgnNode)node;
if (PRAGMAS.contains(localAsgnNode.getName())) {
if (localAsgnNode.getName().equals("__NOFRAME__")) {
noFrame = localAsgnNode.getValueNode() instanceof TrueNode;
}
break;
}
inspect(localAsgnNode.getValueNode());
break;
case LOCALVARNODE:
break;
case MATCHNODE:
inspect(((MatchNode)node).getRegexpNode());
setFlag(BACKREF);
break;
case MATCH2NODE:
Match2Node match2Node = (Match2Node)node;
inspect(match2Node.getReceiverNode());
inspect(match2Node.getValueNode());
setFlag(BACKREF);
break;
case MATCH3NODE:
Match3Node match3Node = (Match3Node)node;
inspect(match3Node.getReceiverNode());
inspect(match3Node.getValueNode());
setFlag(BACKREF);
break;
case MODULENODE:
setFlag(CLASS);
break;
case MULTIPLEASGNNODE:
MultipleAsgnNode multipleAsgnNode = (MultipleAsgnNode)node;
inspect(multipleAsgnNode.getArgsNode());
inspect(multipleAsgnNode.getHeadNode());
inspect(multipleAsgnNode.getValueNode());
break;
case NEWLINENODE:
inspect(((NewlineNode)node).getNextNode());
break;
case NEXTNODE:
inspect(((NextNode)node).getValueNode());
break;
case NILNODE:
break;
case NOTNODE:
inspect(((NotNode)node).getConditionNode());
break;
case NTHREFNODE:
break;
case OPASGNANDNODE:
OpAsgnAndNode opAsgnAndNode = (OpAsgnAndNode)node;
inspect(opAsgnAndNode.getFirstNode());
inspect(opAsgnAndNode.getSecondNode());
break;
case OPASGNNODE:
OpAsgnNode opAsgnNode = (OpAsgnNode)node;
inspect(opAsgnNode.getReceiverNode());
inspect(opAsgnNode.getValueNode());
break;
case OPASGNORNODE:
disable(); // Depends on defined
break;
case OPELEMENTASGNNODE:
OpElementAsgnNode opElementAsgnNode = (OpElementAsgnNode)node;
setFlag(FRAME_SELF);
inspect(opElementAsgnNode.getArgsNode());
inspect(opElementAsgnNode.getReceiverNode());
inspect(opElementAsgnNode.getValueNode());
break;
case ORNODE:
OrNode orNode = (OrNode)node;
inspect(orNode.getFirstNode());
inspect(orNode.getSecondNode());
break;
case POSTEXENODE:
PostExeNode postExeNode = (PostExeNode)node;
setFlag(CLOSURE);
setFlag(SCOPE_AWARE);
inspect(postExeNode.getBodyNode());
inspect(postExeNode.getVarNode());
break;
case PREEXENODE:
PreExeNode preExeNode = (PreExeNode)node;
setFlag(CLOSURE);
setFlag(SCOPE_AWARE);
inspect(preExeNode.getBodyNode());
inspect(preExeNode.getVarNode());
break;
case REDONODE:
break;
case REGEXPNODE:
break;
case ROOTNODE:
inspect(((RootNode)node).getBodyNode());
if (((RootNode)node).getBodyNode() instanceof BlockNode) {
BlockNode blockNode = (BlockNode)((RootNode)node).getBodyNode();
if (blockNode.size() > 500) {
// method has more than 500 lines; we'll need to split it
// and therefore need to use a heap-based scope
setFlag(SCOPE_AWARE);
}
}
break;
case RESCUEBODYNODE:
disable();
break;
case RESCUENODE:
disable();
break;
case RETRYNODE:
disable();
break;
case RETURNNODE:
inspect(((ReturnNode)node).getValueNode());
break;
case SCLASSNODE:
setFlag(CLASS);
break;
case SCOPENODE:
break;
case SELFNODE:
break;
case SPLATNODE:
inspect(((SplatNode)node).getValue());
break;
case STARNODE:
break;
case STRNODE:
break;
case SUPERNODE:
SuperNode superNode = (SuperNode)node;
inspect(superNode.getArgsNode());
inspect(superNode.getIterNode());
break;
case SVALUENODE:
inspect(((SValueNode)node).getValue());
break;
case SYMBOLNODE:
break;
case TOARYNODE:
inspect(((ToAryNode)node).getValue());
break;
case TRUENODE:
break;
case UNDEFNODE:
setFlag(METHOD);
break;
case UNTILNODE:
UntilNode untilNode = (UntilNode)node;
ASTInspector untilInspector = subInspect(
untilNode.getConditionNode(), untilNode.getBodyNode());
// a while node could receive non-local flow control from any of these:
// * a closure within the loop
// * an eval within the loop
// * a block-arg-based proc called within the loop
if (untilInspector.getFlag(CLOSURE) || untilInspector.getFlag(EVAL)) {
untilNode.containsNonlocalFlow = true;
// we set scope-aware to true to force heap-based locals
setFlag(SCOPE_AWARE);
}
break;
case VALIASNODE:
break;
case WHENNODE:
inspect(((WhenNode)node).getBodyNode());
inspect(((WhenNode)node).getExpressionNodes());
inspect(((WhenNode)node).getNextCase());
break;
case WHILENODE:
WhileNode whileNode = (WhileNode)node;
ASTInspector whileInspector = subInspect(
whileNode.getConditionNode(), whileNode.getBodyNode());
// a while node could receive non-local flow control from any of these:
// * a closure within the loop
// * an eval within the loop
// * a block-arg-based proc called within the loop
if (whileInspector.getFlag(CLOSURE) || whileInspector.getFlag(EVAL) || getFlag(BLOCK_ARG)) {
whileNode.containsNonlocalFlow = true;
// we set scope-aware to true to force heap-based locals
setFlag(SCOPE_AWARE);
}
integrate(whileInspector);
break;
case XSTRNODE:
break;
case YIELDNODE:
inspect(((YieldNode)node).getArgsNode());
break;
case ZARRAYNODE:
break;
case ZEROARGNODE:
break;
case ZSUPERNODE:
setFlag(SCOPE_AWARE);
setFlag(ZSUPER);
inspect(((ZSuperNode)node).getIterNode());
break;
default:
// encountered a node we don't recognize, set everything to true to disable optz
assert false : "All nodes should be accounted for in AST inspector: " + node;
disable();
}
}
public boolean hasClass() {
return getFlag(CLASS);
}
public boolean hasClosure() {
return getFlag(CLOSURE);
}
/**
* Whether the tree under inspection contains any method-table mutations,
* including def, defs, undef, and alias.
*
* @return True if there are mutations, false otherwise
*/
public boolean hasMethod() {
return getFlag(METHOD);
}
public boolean hasFrameAwareMethods() {
return getFlag(
FRAME_AWARE | FRAME_BLOCK | FRAME_CLASS | FRAME_NAME | FRAME_SELF | FRAME_VISIBILITY |
CLOSURE | EVAL | BACKREF | LASTLINE | ZSUPER);
}
public boolean hasScopeAwareMethods() {
return getFlag(SCOPE_AWARE);
}
public boolean hasBlockArg() {
return getFlag(BLOCK_ARG);
}
public boolean hasOptArgs() {
return getFlag(OPT_ARGS);
}
public boolean hasRestArg() {
return getFlag(REST_ARG);
}
public boolean hasConstant() {
return getFlag(CONSTANT);
}
public boolean hasClassVar() {
return getFlag(CLASS_VAR);
}
public boolean noFrame() {
return noFrame;
}
}