Bug 433171 - Handle line continuations when parsing build output

Change-Id: I9449e3167eae1464d23948da80663997adf95b16
Signed-off-by: Nathan Ridge <zeratul976@hotmail.com>

build/org.eclipse.cdt.managedbuilder.core.tests/tests/org/eclipse/cdt/managedbuilder/language/settings/providers/tests/GCCBuildCommandParserTest.java

@@ -1130,6 +1130,51 @@ public class GCCBuildCommandParserTest extends BaseTestCase {
 		}
 	}
 
+	/**
+	 * Test use of a line-continuation character ('\') in build output.
+	 */
+	public void testLineContinuation() throws Exception {
+		// Create model project and accompanied descriptions
+		String projectName = getName();
+		IProject project = ResourceHelper.createCDTProjectWithConfig(projectName);
+		ICConfigurationDescription[] cfgDescriptions = getConfigurationDescriptions(project);
+		ICConfigurationDescription cfgDescription = cfgDescriptions[0];
+		
+		IFile file0=ResourceHelper.createFile(project, "file0.cpp");
+		IFile file1=ResourceHelper.createFile(project, "file1.cpp");
+		IFile file2=ResourceHelper.createFile(project, "file2.cpp");
+		ICLanguageSetting ls = cfgDescription.getLanguageSettingForFile(file0.getProjectRelativePath(), true);
+		String languageId = ls.getLanguageId();
+		
+		// create GCCBuildCommandParser
+		GCCBuildCommandParser parser = (GCCBuildCommandParser) LanguageSettingsManager.getExtensionProviderCopy(GCC_BUILD_COMMAND_PARSER_EXT, true);
+		
+		// parse line
+		parser.startup(cfgDescription, null);
+		parser.processLine("gcc file0.cpp -I/path0 \\");
+		parser.processLine("              -I/path1");
+		parser.processLine("gcc file1.cpp -I/path0 \\\\");       // not a continuation, '\' is escaped!
+		parser.processLine("              -I/path1");  
+		parser.processLine("gcc file2.cpp -I/path0 \\");         // continuation at end of last line
+		parser.shutdown();
+		
+		// check populated entries
+		{
+			List<ICLanguageSettingEntry> entries = parser.getSettingEntries(cfgDescription, file0, languageId);
+			assertEquals(new CIncludePathEntry("/path0", 0), entries.get(0));
+			assertEquals(new CIncludePathEntry("/path1", 0), entries.get(1));
+		}
+		{
+			List<ICLanguageSettingEntry> entries = parser.getSettingEntries(cfgDescription, file1, languageId);
+			assertEquals(new CIncludePathEntry("/path0", 0), entries.get(0));
+			assertEquals(1, entries.size());
+		}
+		{
+			List<ICLanguageSettingEntry> entries = parser.getSettingEntries(cfgDescription, file2, languageId);
+			assertEquals(new CIncludePathEntry("/path0", 0), entries.get(0));
+		}
+	}
+	
 	/**
 	 * Test parsing of paths located on a different drive on Windows.
 	 */

build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/language/settings/providers/AbstractBuildCommandParser.java

@@ -71,6 +71,9 @@ public abstract class AbstractBuildCommandParser extends AbstractLanguageSetting
 	// cached value from properties, do not need to use in equals() and hashCode()
 	private ResourceScope resourceScope = null;
 	
+	// Used to handle line continuations in the build output.
+	private String partialLine;
+
 	/**
 	 * The compiler command pattern without specifying compiler options.
 	 * The options are intended to be handled with option parsers,
@@ -241,10 +244,51 @@ public abstract class AbstractBuildCommandParser extends AbstractLanguageSetting
 
 	@Override
 	public void shutdown() {
+		// If there's an unprocessed partial line (because the last line of the build output ended
+		// in a line-continuation character), process it.
+		if (partialLine != null) {
+			processLine(partialLine);
+			partialLine = null;
+		}
+		
 		serializeLanguageSettingsInBackground();
 		super.shutdown();
 	}
 	
+	@Override
+	public boolean processLine(String line) {
+		line = handleLineContinuation(line);
+		return super.processLine(line);
+	}
+	
+	/**
+	 * Handle line continuations ('\' at the end of a line, indicating that the next line is a
+	 * continuation of this one).
+	 */
+	private String handleLineContinuation(String line) {
+		if (line == null) 
+			return null;
+
+		// If the character preceding the '\' is also '\', it's not a line continuation - 
+		// the first '\' escapes the second.
+		if (line.length() > 0 && line.charAt(line.length() - 1) == '\\' &&
+				(line.length() == 1 || line.charAt(line.length() - 2) != '\\')) {
+			// Line ends in line continuation - save it for later.
+			String fragment = line.substring(0, line.length() - 1);
+			if (partialLine == null) {
+				partialLine = fragment;
+			} else {
+				partialLine += fragment;
+			}
+			return null;  // line will not be processed now
+		} else if (partialLine != null) {
+			// Line doesn't end in continuation but previous lines did - use their contents.
+			line = partialLine + line;
+			partialLine = null;
+		}
+		return line;
+	}
+
 	/**
 	 * Trivial Error Parser which allows highlighting of output lines matching the patterns
 	 * of this parser. Intended for better troubleshooting experience.