Bug 559007 - Added new option to C-style cast checker

Add a new option to check in macro expansion. User, if want, can
disable this warning if it's in a macro expansion since the macro
used can be out of control of the user, for example a system
macro like FD_SET could be used.

Change-Id: I0efaaedd09087de87d9340d81ddbd7f2dc1e1abb
Signed-off-by: Marco Stornelli <marco.stornelli@gmail.com>

codan/org.eclipse.cdt.codan.checkers/src/org/eclipse/cdt/codan/internal/checkers/CStyleCastChecker.java

@@ -11,17 +11,38 @@
 package org.eclipse.cdt.codan.internal.checkers;
 
 import org.eclipse.cdt.codan.core.cxx.model.AbstractIndexAstChecker;
+import org.eclipse.cdt.codan.core.model.IProblem;
+import org.eclipse.cdt.codan.core.model.IProblemWorkingCopy;
 import org.eclipse.cdt.core.dom.ILinkage;
 import org.eclipse.cdt.core.dom.ast.ASTVisitor;
 import org.eclipse.cdt.core.dom.ast.IASTCastExpression;
 import org.eclipse.cdt.core.dom.ast.IASTExpression;
+import org.eclipse.cdt.core.dom.ast.IASTMacroExpansionLocation;
+import org.eclipse.cdt.core.dom.ast.IASTNodeLocation;
 import org.eclipse.cdt.core.dom.ast.IASTTranslationUnit;
 
 public class CStyleCastChecker extends AbstractIndexAstChecker {
 	public static final String ERR_ID = "org.eclipse.cdt.codan.internal.checkers.CStyleCastProblem"; //$NON-NLS-1$
+	public static final String PARAM_MACRO = "checkMacro"; //$NON-NLS-1$
+	private boolean checkMacro = true;
+
+	@Override
+	public void initPreferences(IProblemWorkingCopy problem) {
+		super.initPreferences(problem);
+		addPreference(problem, PARAM_MACRO, CheckersMessages.Copyright_regex, true);
+	}
+
+	private boolean enclosedInMacroExpansion(IASTExpression statement) {
+		if (!checkMacro)
+			return false;
+		IASTNodeLocation[] locations = statement.getNodeLocations();
+		return locations.length == 1 && locations[0] instanceof IASTMacroExpansionLocation;
+	}
 
 	@Override
 	public void processAst(IASTTranslationUnit ast) {
+		final IProblem pt = getProblemById(ERR_ID, getFile());
+		checkMacro = (boolean) getPreference(pt, PARAM_MACRO);
 		if (ast.getLinkage().getLinkageID() == ILinkage.CPP_LINKAGE_ID) {
 			ast.accept(new ASTVisitor() {
 				{
@@ -30,7 +51,7 @@ public class CStyleCastChecker extends AbstractIndexAstChecker {
 
 				@Override
 				public int visit(IASTExpression expression) {
-					if (expression instanceof IASTCastExpression) {
+					if (expression instanceof IASTCastExpression && !enclosedInMacroExpansion(expression)) {
 						if (((IASTCastExpression) expression).getOperator() == IASTCastExpression.op_cast)
 							reportProblem(ERR_ID, expression);
 					}

codan/org.eclipse.cdt.codan.checkers/src/org/eclipse/cdt/codan/internal/checkers/CheckersMessages.java

@@ -43,10 +43,9 @@ public class CheckersMessages extends NLS {
 	public static String UnusedSymbolInFileScopeChecker_CharacterSequence;
 	public static String UnusedSymbolInFileScopeChecker_Exceptions;
 	public static String SymbolShadowingChecker_CheckFunctionParameters;
-
 	public static String Copyright_regex;
-
 	public static String ShallowCopyChecker_OnlyNew;
+	public static String CStyleCastCheck_checkInMacro;
 
 	static {
 		NLS.initializeMessages(CheckersMessages.class.getName(), CheckersMessages.class);

codan/org.eclipse.cdt.codan.checkers/src/org/eclipse/cdt/codan/internal/checkers/CheckersMessages.properties

@@ -23,6 +23,7 @@ ReturnChecker_Param0=Also check functions with implicit return value
 GenericParameter_ParameterExceptions=Exceptions (value of the problem argument)
 GenericParameter_ParameterExceptionsItem=Value of the argument
 StatementHasNoEffectChecker_ParameterMacro=Report problem in statements that come from macro expansion
+CStyleCastCheck_checkInMacro=Report problem in expressions that come from macro expansion
 SuggestedParenthesisChecker_SuggestParanthesesAroundNot=Suggest parenthesis around 'not' operator
 SuspiciousSemicolonChecker_ParamAfterElse=Report an error if semicolon is right after 'else' statement
 SuspiciousSemicolonChecker_ParamElse=Do not report an error after 'if' when 'else' exists

codan/org.eclipse.cdt.codan.core.tests/src/org/eclipse/cdt/codan/core/internal/checkers/CStyleCastCheckerTest.java

@@ -47,4 +47,14 @@ public class CStyleCastCheckerTest extends CheckerTestCase {
 		loadCodeAndRun(getAboveComment());
 		checkNoErrorsOfKind(ERR_ID);
 	}
+
+	//#define CAST(X) (void)X
+	//void bar() {
+	//  int b;
+	//	CAST(b);
+	//};
+	public void testInMacro() throws Exception {
+		loadCodeAndRun(getAboveComment());
+		checkNoErrorsOfKind(ERR_ID);
+	}
 }