* Check added to catch if the same variable is set twice in the same update

* New class of semantic checks created that are only done after constant definitions


git-svn-id: https://www.prismmodelchecker.org/svn/prism/prism/trunk@3231 bbc10eb1-c90d-0410-af57-cb519fbb1720

prism/src/parser/ast/ASTElement.java

@@ -373,9 +373,9 @@ public abstract class ASTElement
 	}
 
 	/**
-	 * Perform any required semantic checks. Optionally pass in parent
-	 * ModulesFile and PropertiesFile for some additional checks (or leave
-	 * null);
+	 * Perform any required semantic checks. Optionally pass in parent ModulesFile
+	 * and PropertiesFile for some additional checks (or leave null);
+	 * These checks are done *before* any undefined constants have been defined.
 	 */
 	public void semanticCheck(ModulesFile modulesFile, PropertiesFile propertiesFile) throws PrismLangException
 	{
@@ -383,6 +383,17 @@ public abstract class ASTElement
 		accept(visitor);
 	}
 
+	/**
+	 * Perform further semantic checks that can only be done once values
+	 * for any undefined constants have been defined. Optionally pass in parent
+	 * ModulesFile and PropertiesFile for some additional checks (or leave null);
+	 */
+	public void semanticCheckAfterConstants(ModulesFile modulesFile, PropertiesFile propertiesFile) throws PrismLangException
+	{
+		SemanticCheckAfterConstants visitor = new SemanticCheckAfterConstants(modulesFile, propertiesFile);
+		accept(visitor);
+	}
+
 	/**
 	 * Evaluate partially: replace some constants and variables with actual values. 
 	 */

prism/src/parser/ast/ModulesFile.java

@@ -763,6 +763,7 @@ public class ModulesFile extends ASTElement
 	public void setUndefinedConstants(Values someValues) throws PrismLangException
 	{
 		constantValues = constantList.evaluateConstants(someValues, null);
+		semanticCheckAfterConstants(this, null);
 	}
 
 	/**

prism/src/parser/ast/PropertiesFile.java

@@ -371,6 +371,7 @@ public class PropertiesFile extends ASTElement
 	{
 		// might need values for ModulesFile constants too
 		constantValues = constantList.evaluateConstants(someValues, modulesFile.getConstantValues());
+		semanticCheckAfterConstants(modulesFile, this);
 	}
 	
 	/**

prism/src/parser/visitor/SemanticCheck.java

@@ -36,6 +36,7 @@ import prism.PrismLangException;
 /**
  * Perform any required semantic checks. Optionally pass in parent ModulesFile
  * and PropertiesFile for some additional checks (or leave null);
+ * These checks are done *before* any undefined constants have been defined.
  */
 public class SemanticCheck extends ASTTraverse
 {

prism/src/parser/visitor/SemanticCheckAfterConstants.java

@@ -0,0 +1,89 @@
+//==============================================================================
+//	
+//	Copyright (c) 2002-
+//	Authors:
+//	* Dave Parker <david.parker@comlab.ox.ac.uk> (University of Oxford)
+//	
+//------------------------------------------------------------------------------
+//	
+//	This file is part of PRISM.
+//	
+//	PRISM is free software; you can redistribute it and/or modify
+//	it under the terms of the GNU General Public License as published by
+//	the Free Software Foundation; either version 2 of the License, or
+//	(at your option) any later version.
+//	
+//	PRISM 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 for more details.
+//	
+//	You should have received a copy of the GNU General Public License
+//	along with PRISM; if not, write to the Free Software Foundation,
+//	Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//	
+//==============================================================================
+
+package parser.visitor;
+
+import java.util.Vector;
+
+import parser.ast.*;
+import prism.PrismLangException;
+
+/**
+ * Perform further semantic checks that can only be done once values
+ * for any undefined constants have been defined. Optionally pass in parent
+ * ModulesFile and PropertiesFile for some additional checks (or leave null);
+ */
+public class SemanticCheckAfterConstants extends ASTTraverse
+{
+	private ModulesFile modulesFile;
+	private PropertiesFile propertiesFile;
+
+	public SemanticCheckAfterConstants()
+	{
+		this(null, null);
+	}
+
+	public SemanticCheckAfterConstants(ModulesFile modulesFile)
+	{
+		this(modulesFile, null);
+	}
+
+	public SemanticCheckAfterConstants(ModulesFile modulesFile, PropertiesFile propertiesFile)
+	{
+		setModulesFile(modulesFile);
+		setPropertiesFile(propertiesFile);
+	}
+
+	public void setModulesFile(ModulesFile modulesFile)
+	{
+		this.modulesFile = modulesFile;
+	}
+
+	public void setPropertiesFile(PropertiesFile propertiesFile)
+	{
+		this.propertiesFile = propertiesFile;
+	}
+
+	public void visitPost(Update e) throws PrismLangException
+	{
+		int i, n;
+		String var;
+		Vector<String> varsUsed = new Vector<String>();
+
+		// Check that no variables are set twice in the same update
+		// Currently, could do this *before* constants are defined,
+		// but one day we might need to worry about e.g. array indices...
+		n = e.getNumElements();
+		for (i = 0; i < n; i++) {
+			var = e.getVar(i);
+			if (varsUsed.contains(var)) {
+				throw new PrismLangException("Variable \"" + var + "\" is set twice in the same update", e.getVarIdent(i));
+			}
+			varsUsed.add(var);
+		}
+		varsUsed.clear();
+	}
+}