Bug 350144 - suppressing the "No break" problem with regexp

added regex support for suppression comment

Change-Id: I590d171fcce23d547a489e42a791aa484963d4a6
Signed-off-by: Alena Laskavaia <elaskavaia.cdt@gmail.com>

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

@@ -12,6 +12,10 @@
  *******************************************************************************/
 package org.eclipse.cdt.codan.internal.checkers;
 
+import java.util.regex.Pattern;
+import java.util.regex.PatternSyntaxException;
+
+import org.eclipse.cdt.codan.checkers.CodanCheckersActivator;
 import org.eclipse.cdt.codan.core.cxx.CxxAstUtils;
 import org.eclipse.cdt.codan.core.cxx.model.AbstractIndexAstChecker;
 import org.eclipse.cdt.codan.core.model.ICheckerWithPreferences;
@@ -50,9 +54,11 @@ public class CaseBreakChecker extends AbstractIndexAstChecker implements IChecke
 	private boolean fCheckLastCase; // Should we check the last case in the switch?
 	private boolean fCheckEmptyCase; // Should we check an empty case (a case without any statements within it)
 	private String fNoBreakComment; // The comment suppressing this warning
+	private Pattern fNoBreakRegex;
 
 	/**
-	 * This visitor looks for "switch" statements and invokes "SwitchVisitor" on them.
+	 * This visitor looks for "switch" statements and invokes "SwitchVisitor" on
+	 * them.
 	 */
 	class SwitchFindingVisitor extends ASTVisitor {
 		SwitchFindingVisitor() {
@@ -129,9 +135,14 @@ public class CaseBreakChecker extends AbstractIndexAstChecker implements IChecke
 										comment = getFreestandingComment(body);
 								}
 								if (comment != null) {
+									// for backward compatibility leave original rule of checking string as non-regex
 									String str = getTrimmedComment(comment);
 									if (str.toLowerCase().contains(fNoBreakComment.toLowerCase()))
 										continue;
+						
+									if (fNoBreakRegex != null && fNoBreakRegex.matcher(str).find()) {
+										continue;
+									}
 								}
 								reportProblem(curr);
 							}
@@ -261,7 +272,8 @@ public class CaseBreakChecker extends AbstractIndexAstChecker implements IChecke
 				DEFAULT_NO_BREAK_COMMENT);
 		addPreference(problem, PARAM_LAST_CASE, CheckersMessages.CaseBreakChecker_LastCaseDescription, Boolean.FALSE);
 		addPreference(problem, PARAM_EMPTY_CASE, CheckersMessages.CaseBreakChecker_EmptyCaseDescription, Boolean.FALSE);
-		addPreference(problem, PARAM_ENABLE_FALLTHROUGH_QUICKFIX, CheckersMessages.CaseBreakChecker_EnableFallthroughQuickfixDescription, Boolean.FALSE);
+		addPreference(problem, PARAM_ENABLE_FALLTHROUGH_QUICKFIX, CheckersMessages.CaseBreakChecker_EnableFallthroughQuickfixDescription,
+				Boolean.FALSE);
 	}
 
 	@Override
@@ -269,6 +281,13 @@ public class CaseBreakChecker extends AbstractIndexAstChecker implements IChecke
 		fCheckLastCase = (Boolean) getPreference(getProblemById(ER_ID, getFile()), PARAM_LAST_CASE);
 		fCheckEmptyCase = (Boolean) getPreference(getProblemById(ER_ID, getFile()), PARAM_EMPTY_CASE);
 		fNoBreakComment = (String) getPreference(getProblemById(ER_ID, getFile()), PARAM_NO_BREAK_COMMENT);
+		try {
+			if (fNoBreakComment != null)
+				fNoBreakRegex = Pattern.compile(fNoBreakComment, Pattern.CASE_INSENSITIVE);
+		} catch (PatternSyntaxException e) {
+			CodanCheckersActivator.log(e);
+			fNoBreakRegex = null;
+		}
 		SwitchFindingVisitor visitor = new SwitchFindingVisitor();
 		ast.accept(visitor);
 	}

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

@@ -8,7 +8,7 @@
 # Contributors:
 #     Alena Laskavaia - initial API and implementation
 ###############################################################################
-CaseBreakChecker_DefaultNoBreakCommentDescription=Comment text to suppress the problem: 
+CaseBreakChecker_DefaultNoBreakCommentDescription=Comment text to suppress the problem (or regular expression): 
 CaseBreakChecker_EmptyCaseDescription=Check also empty 'case' statement (except if last)
 CaseBreakChecker_LastCaseDescription=Check also the last 'case' statement
 CaseBreakChecker_EnableFallthroughQuickfixDescription=Enable quick fix to add fallthrough attribute (C++17)

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

@@ -627,6 +627,11 @@ public class CaseBreakCheckerTest extends CheckerTestCase {
 		pref.setValue(val);
 	}
 
+	private void setComment(String str) {
+		IProblemPreference pref = getPreference(CaseBreakChecker.ER_ID, CaseBreakChecker.PARAM_NO_BREAK_COMMENT);
+		pref.setValue(str);
+	}
+
 	// void foo(int a) {
 	//   switch (a) {
 	//   case 1:
@@ -765,4 +770,35 @@ public class CaseBreakCheckerTest extends CheckerTestCase {
 		loadCodeAndRun(code);
 		checkNoErrorsOfKind(ER_ID);
 	}
+
+	// void foo(void) {
+	//  int a, b;
+	//  switch (a) {
+	//  case 1:
+	//    b = 2;
+	//    // lolo
+	//    /* fallthru */
+	//  case 2:
+	//    b = 2;
+	//    /* falls thru */
+	//    // lolo
+	//  case 3:
+	//    /* no break */
+	//    b = 2;
+	//    // loo
+	//  case 4:
+	//    b = 2;
+	//    // lolo
+	//    /* fallthrough */
+	//  case 5:
+	//    // lolo
+	//    b = 2;
+	//    /* fall-thru */
+	//  }
+	// }
+	public void testCommentsParam() throws Exception {
+		setComment("fall(s)?[ \\t-]*thr(ough|u)");
+		loadCodeAndRun(getAboveComment());
+		checkErrorLines(9, 14);
+	}
 }