root / trunk / compiler / ooasCompiler / src / org / momut / ooas / visitors / OoaActionClassifierVisitor.java @ 9
| 1 |
/**
|
|---|---|
| 2 |
*
|
| 3 |
* OOAS Compiler
|
| 4 |
*
|
| 5 |
* Copyright 2015, AIT Austrian Institute of Technology.
|
| 6 |
* This code is based on the C# Version of the OOAS Compiler, which is
|
| 7 |
* copyright 2015 by the Institute of Software Technology, Graz University
|
| 8 |
* of Technology with portions copyright by the AIT Austrian Institute of
|
| 9 |
* Technology. All rights reserved.
|
| 10 |
*
|
| 11 |
* SEE THE "LICENSE" FILE FOR THE TERMS UNDER WHICH THIS FILE IS PROVIDED.
|
| 12 |
*
|
| 13 |
* If you modify the file please update the list of contributors below to in-
|
| 14 |
* clude your name. Please also stick to the coding convention of using TABs
|
| 15 |
* to do the basic (block-level) indentation and spaces for anything after
|
| 16 |
* that. (Enable the display of special chars and it should be pretty obvious
|
| 17 |
* what this means.) Also, remove all trailing whitespace.
|
| 18 |
*
|
| 19 |
* Contributors:
|
| 20 |
* Willibald Krenn (AIT)
|
| 21 |
* Stephan Zimmerer (AIT)
|
| 22 |
* Markus Demetz (AIT)
|
| 23 |
* Christoph Czurda (AIT)
|
| 24 |
*
|
| 25 |
*/
|
| 26 |
|
| 27 |
|
| 28 |
package org.momut.ooas.visitors; |
| 29 |
|
| 30 |
import java.util.LinkedList; |
| 31 |
|
| 32 |
import org.momut.ooas.ast.expressions.Expression; |
| 33 |
import org.momut.ooas.ast.identifiers.FunctionIdentifier; |
| 34 |
import org.momut.ooas.ast.identifiers.Identifier; |
| 35 |
import org.momut.ooas.ast.identifiers.IdentifierKind; |
| 36 |
import org.momut.ooas.ast.identifiers.MethodIdentifier; |
| 37 |
import org.momut.ooas.ast.identifiers.NamedActionIdentifier; |
| 38 |
import org.momut.ooas.ast.statements.Assignment; |
| 39 |
import org.momut.ooas.ast.statements.Block; |
| 40 |
import org.momut.ooas.ast.statements.Call; |
| 41 |
import org.momut.ooas.ast.statements.Statement; |
| 42 |
import org.momut.ooas.ast.statements.StatementKind; |
| 43 |
import org.momut.ooas.ast.types.FunctionType; |
| 44 |
import org.momut.ooas.ast.types.OoActionSystemType; |
| 45 |
import org.momut.ooas.ast.types.FunctionType.FunctionTypeEnum; |
| 46 |
import org.momut.ooas.parser.ParserMessage; |
| 47 |
import org.momut.ooas.parser.ParserState; |
| 48 |
import org.momut.ooas.utils.exceptions.NotImplementedException; |
| 49 |
|
| 50 |
/// <summary>
|
| 51 |
/// This visitor scans all methods and named actions in order to check
|
| 52 |
/// whether they are safe, in the sense that they are only using
|
| 53 |
/// basic commands that obey the excluded miracle rule automatically.
|
| 54 |
///
|
| 55 |
/// The idea is that the weakest precondition of "safe named actions"
|
| 56 |
/// automatically is the guard of the obligatorty guarded command.
|
| 57 |
///
|
| 58 |
/// Allowed commands for "safe" code:
|
| 59 |
/// -> Assignment (deterministic!)
|
| 60 |
/// -> Sequential Composition
|
| 61 |
/// Currently not supported within the analysis:
|
| 62 |
/// -> Conditional Statement (emulated by requires A: end [] requires not A: end)
|
| 63 |
/// -> Iteration (not available)
|
| 64 |
/// </summary>
|
| 65 |
public final class OoaActionClassifierVisitor extends OoaCompleteAstTraversalVisitor |
| 66 |
{
|
| 67 |
private static final class RefWorkAround { |
| 68 |
boolean m_hasUnsafeElement;
|
| 69 |
Statement ablock;
|
| 70 |
public RefWorkAround(boolean ue, Statement b) { |
| 71 |
m_hasUnsafeElement = ue; |
| 72 |
ablock = b; |
| 73 |
} |
| 74 |
} |
| 75 |
|
| 76 |
private boolean getValue(Boolean input, boolean defaultValue) { |
| 77 |
return input == null ? defaultValue: input; |
| 78 |
} |
| 79 |
|
| 80 |
|
| 81 |
@SuppressWarnings("serial") |
| 82 |
private void CalcBodySafe(FunctionIdentifier methodIdentifier, FunctionType mType, final RefWorkAround w) |
| 83 |
{
|
| 84 |
String methodAction;
|
| 85 |
if (mType.functionType() == FunctionTypeEnum.Method)
|
| 86 |
methodAction = "Method";
|
| 87 |
else
|
| 88 |
methodAction = "Action";
|
| 89 |
|
| 90 |
|
| 91 |
while ((w.ablock != null) && (w.ablock.kind() == StatementKind.PrioBlock || w.ablock.kind() == StatementKind.NondetBlock)) |
| 92 |
{
|
| 93 |
final Block block = (Block) w.ablock;
|
| 94 |
if (block.statements().size() == 0) |
| 95 |
break;
|
| 96 |
|
| 97 |
if (block.statements().size() > 1) |
| 98 |
{
|
| 99 |
m_ParserState.AddMessage( |
| 100 |
new ParserMessage(m_ParserState.filename, w.ablock.line(),
|
| 101 |
w.ablock.pos(), String.format("%s %s extended: More than one element in Nondet/Prio Block.", |
| 102 |
methodAction, methodIdentifier.tokenText()))); |
| 103 |
mType.SetMiracleSafe(false);
|
| 104 |
} |
| 105 |
w.ablock = block.statements().peekFirst(); |
| 106 |
} |
| 107 |
|
| 108 |
final LinkedList<Statement> stmts = w.ablock.kind() == StatementKind.SeqBlock ? ((Block) w.ablock).statements() : new LinkedList<Statement>(){{add(w.ablock);}}; |
| 109 |
for (final Statement s: stmts) |
| 110 |
{
|
| 111 |
switch (s.kind())
|
| 112 |
{
|
| 113 |
case Abort:
|
| 114 |
// abort maps any postcondition to false, iow. wp(abort,X) = false
|
| 115 |
w.m_hasUnsafeElement = true; // excluded miracle holds, but I'm not sure about continuity.. *g* |
| 116 |
m_ParserState.AddMessage( |
| 117 |
new ParserMessage(m_ParserState.filename, w.ablock.line(),
|
| 118 |
w.ablock.pos(), String.format("%s %s extended: Abort detected.", |
| 119 |
methodAction, methodIdentifier.tokenText()))); |
| 120 |
break;
|
| 121 |
case Assignment:
|
| 122 |
final Assignment ass = (Assignment)s;
|
| 123 |
w.m_hasUnsafeElement |= ass.nondetExpression() != null;
|
| 124 |
if (w.m_hasUnsafeElement)
|
| 125 |
m_ParserState.AddMessage( |
| 126 |
new ParserMessage(m_ParserState.filename, w.ablock.line(),
|
| 127 |
w.ablock.pos(), String.format("%s %s extended: possibly nondeterministic assignment.", |
| 128 |
methodAction, methodIdentifier.tokenText()))); |
| 129 |
// check value expressions
|
| 130 |
for (final Expression x: ass.values()) |
| 131 |
{
|
| 132 |
if (x.GetUninitializedFreeVariables().size() > 0) |
| 133 |
{
|
| 134 |
w.m_hasUnsafeElement = true;
|
| 135 |
m_ParserState.AddMessage( |
| 136 |
new ParserMessage(m_ParserState.filename, w.ablock.line(),
|
| 137 |
w.ablock.pos(), String.format("%s %s extended: uninitialized free variables in expression.", |
| 138 |
methodAction, methodIdentifier.tokenText()))); |
| 139 |
continue;
|
| 140 |
} |
| 141 |
for (final FunctionIdentifier ct: x.callTargets()) |
| 142 |
{
|
| 143 |
if ( ((FunctionType)ct.type()).isMiracleSafe() == null) |
| 144 |
ct.Accept(this);
|
| 145 |
w.m_hasUnsafeElement |= getValue(((FunctionType)ct.type()).isMiracleSafe(), true);
|
| 146 |
if (w.m_hasUnsafeElement)
|
| 147 |
m_ParserState.AddMessage( |
| 148 |
new ParserMessage(m_ParserState.filename, w.ablock.line(),
|
| 149 |
w.ablock.pos(), String.format("%s %s extended: call of extended method in value expression.", |
| 150 |
methodAction, methodIdentifier.tokenText()))); |
| 151 |
} |
| 152 |
} |
| 153 |
break;
|
| 154 |
case GuardedCommand:
|
| 155 |
w.m_hasUnsafeElement = true; // we do not allow guarded commands in methods as they would be included in actions! |
| 156 |
// we do not allow a second guarded command in named actions.
|
| 157 |
m_ParserState.AddMessage( |
| 158 |
new ParserMessage(m_ParserState.filename, w.ablock.line(),
|
| 159 |
w.ablock.pos(), String.format("%s %s extended: guarded command detected.", |
| 160 |
methodAction, methodIdentifier.tokenText()))); |
| 161 |
break;
|
| 162 |
case Kill:
|
| 163 |
w.m_hasUnsafeElement = true;
|
| 164 |
m_ParserState.AddMessage( |
| 165 |
new ParserMessage(m_ParserState.filename, w.ablock.line(),
|
| 166 |
w.ablock.pos(), String.format("%s %s extended: Kill detected.", |
| 167 |
methodAction, methodIdentifier.tokenText()))); |
| 168 |
break;
|
| 169 |
case MethodCall:
|
| 170 |
final Call acall = (Call)s;
|
| 171 |
|
| 172 |
for (final FunctionIdentifier anid: acall.callExpression().callTargets()) |
| 173 |
{
|
| 174 |
final FunctionType atype = (FunctionType)anid.type();
|
| 175 |
if (atype.isMiracleSafe() == null) |
| 176 |
atype.identifier().Accept(this);
|
| 177 |
w.m_hasUnsafeElement |= getValue(atype.isMiracleSafe(), true);
|
| 178 |
if (w.m_hasUnsafeElement)
|
| 179 |
m_ParserState.AddMessage( |
| 180 |
new ParserMessage(m_ParserState.filename, w.ablock.line(),
|
| 181 |
w.ablock.pos(), String.format("%s %s extended: calls extended method '%s'.", |
| 182 |
methodAction, methodIdentifier.tokenText(),anid.tokenText()))); |
| 183 |
} |
| 184 |
break;
|
| 185 |
case NondetBlock:
|
| 186 |
w.m_hasUnsafeElement = true;
|
| 187 |
m_ParserState.AddMessage( |
| 188 |
new ParserMessage(m_ParserState.filename, w.ablock.line(),
|
| 189 |
w.ablock.pos(), String.format("%s %s extended: more than one nondet-block.", |
| 190 |
methodAction, methodIdentifier.tokenText()))); |
| 191 |
break;
|
| 192 |
case PrioBlock:
|
| 193 |
w.m_hasUnsafeElement = true;
|
| 194 |
m_ParserState.AddMessage( |
| 195 |
new ParserMessage(m_ParserState.filename, w.ablock.line(),
|
| 196 |
w.ablock.pos(), String.format("%s %s extended: more than one prio block.", |
| 197 |
methodAction, methodIdentifier.tokenText()))); |
| 198 |
break;
|
| 199 |
case Skip:
|
| 200 |
case Break:
|
| 201 |
break;
|
| 202 |
case SeqBlock:
|
| 203 |
// seq block in seq block should not occur..
|
| 204 |
default:
|
| 205 |
throw new NotImplementedException(); |
| 206 |
} |
| 207 |
if (w.m_hasUnsafeElement)
|
| 208 |
break;
|
| 209 |
} |
| 210 |
} |
| 211 |
|
| 212 |
|
| 213 |
@Override
|
| 214 |
public void visit(MethodIdentifier methodIdentifier) |
| 215 |
{
|
| 216 |
final FunctionType mType = (FunctionType)methodIdentifier.type();
|
| 217 |
if (mType.isMiracleSafe() != null) |
| 218 |
return;
|
| 219 |
|
| 220 |
// AST of method may have one prioritized block before the nondet block
|
| 221 |
// both blocks must not have more than one element. (we do not implement conditional)
|
| 222 |
final RefWorkAround w = new RefWorkAround(false, methodIdentifier.body()); |
| 223 |
CalcBodySafe(methodIdentifier, mType, w); |
| 224 |
|
| 225 |
/*
|
| 226 |
if (!m_hasUnsafeElement)
|
| 227 |
m_ParserState.AddMessage(
|
| 228 |
new ParserMessage(m_ParserState.filename, ablock.line,
|
| 229 |
ablock.pos, String.Format("Found basic method: '%s'",
|
| 230 |
methodIdentifier.tokenText)));
|
| 231 |
*/
|
| 232 |
|
| 233 |
mType.SetMiracleSafe(!w.m_hasUnsafeElement); |
| 234 |
} |
| 235 |
|
| 236 |
|
| 237 |
@Override
|
| 238 |
public void visit(NamedActionIdentifier namedActionIdentifier) |
| 239 |
{
|
| 240 |
final FunctionType mType = (FunctionType)namedActionIdentifier.type();
|
| 241 |
if (mType.isMiracleSafe() != null) |
| 242 |
return;
|
| 243 |
|
| 244 |
final RefWorkAround w = new RefWorkAround(false, namedActionIdentifier.body()); |
| 245 |
|
| 246 |
CalcBodySafe(namedActionIdentifier, mType, w); |
| 247 |
/*
|
| 248 |
if (!hasUnsafeElement)
|
| 249 |
m_ParserState.AddMessage(
|
| 250 |
new ParserMessage(m_ParserState.filename, ablock.line,
|
| 251 |
ablock.pos, String.Format("Found basic action: '%s'",
|
| 252 |
namedActionIdentifier.tokenText)));
|
| 253 |
*/
|
| 254 |
mType.SetMiracleSafe(!w.m_hasUnsafeElement); |
| 255 |
} |
| 256 |
|
| 257 |
@Override
|
| 258 |
public void visit(OoActionSystemType ooActionSystemType) |
| 259 |
{
|
| 260 |
super.visit(ooActionSystemType);
|
| 261 |
boolean allsafe = true; |
| 262 |
for (final Identifier x: ooActionSystemType.symbols().symbolList()) |
| 263 |
{
|
| 264 |
if (x.kind() == IdentifierKind.MethodIdentifier
|
| 265 |
|| x.kind() == IdentifierKind.NamedActionIdentifier) |
| 266 |
{
|
| 267 |
allsafe &= getValue(((FunctionType)x.type()).isMiracleSafe(), false);
|
| 268 |
} |
| 269 |
} |
| 270 |
if (allsafe)
|
| 271 |
m_ParserState.AddMessage( |
| 272 |
new ParserMessage(m_ParserState.filename, ooActionSystemType.identifier().line(),
|
| 273 |
ooActionSystemType.identifier().column(), String.format("Found action system with basic actions/methods only: '%s'", |
| 274 |
ooActionSystemType.identifier().tokenText()))); |
| 275 |
} |
| 276 |
|
| 277 |
|
| 278 |
public OoaActionClassifierVisitor(ParserState aState)
|
| 279 |
{
|
| 280 |
super (aState);
|
| 281 |
} |
| 282 |
} |