Bug 565553 - Improve performance of build command parsers with large number of files

Narrow down parsers based on option string

Instead of trying to match all patterns one by one, we can check the
start of the option string to be parsed and narrow down which pattern
(parsers) should be used.

Doing so is much less elegant code-wise as we are "unrolling" the
beginning of the patterns by hand, but it gives a good speed up. Around
300ms saved with a test of LLVM code base (~50% of parseOption time) and
much larger gains on much larger projects or course.

Change-Id: I9e841e7233078d6e38ad08943d98966d0e3c661e
Signed-off-by: Marc-Andre Laperle <malaperle@gmail.com>

2 files changed, 118 insertions, 9 deletions

diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/language/settings/providers/AbstractLanguageSettingsOutputScanner.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/language/settings/providers/AbstractLanguageSettingsOutputScanner.java
index 56ac320955e..0576eb01a0d 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/language/settings/providers/AbstractLanguageSettingsOutputScanner.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/language/settings/providers/AbstractLanguageSettingsOutputScanner.java
@@ -419,6 +419,20 @@ public abstract class AbstractLanguageSettingsOutputScanner extends LanguageSett
 	protected abstract AbstractOptionParser[] getOptionParsers();
 
 	/**
+	 * @return array of option parsers defining how to parse a string to
+	 * {@link ICLanguageSettingEntry}.
+	 * See {@link AbstractOptionParser} and its specific extenders.
+	 *
+	 * @param optionToParse the option string to be parsed.
+	 * This can be used as a hint in order to return a subset of parsers, for better performance.
+	 *
+	 * @since 9.1
+	 */
+	protected AbstractOptionParser[] getOptionParsers(String optionToParse) {
+		return getOptionParsers();
+	}
+
+	/**
 	 * @return {@code true} when the provider tries to resolve relative or remote paths
 	 * to the existing paths in the workspace or local file-system using certain heuristics.
 	 */
@@ -499,8 +513,8 @@ public abstract class AbstractLanguageSettingsOutputScanner extends LanguageSett
 
 		List<String> options = parseOptions(line);
 		if (options != null) {
-			AbstractOptionParser[] optionParsers = getOptionParsers();
 			for (String option : options) {
+				AbstractOptionParser[] optionParsers = getOptionParsers(option);
 				for (AbstractOptionParser optionParser : optionParsers) {
 					try {
 						if (optionParser.parseOption(option)) {
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/language/settings/providers/GCCBuildCommandParser.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/language/settings/providers/GCCBuildCommandParser.java
index 9aeff8a0cc2..64e6507df4b 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/language/settings/providers/GCCBuildCommandParser.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/language/settings/providers/GCCBuildCommandParser.java
@@ -13,6 +13,11 @@
  *******************************************************************************/
 package org.eclipse.cdt.managedbuilder.language.settings.providers;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
 import org.eclipse.cdt.core.errorparsers.RegexErrorPattern;
 import org.eclipse.cdt.core.language.settings.providers.ILanguageSettingsEditableProvider;
 import org.eclipse.cdt.core.settings.model.ICSettingEntry;
@@ -32,34 +37,124 @@ import org.eclipse.cdt.core.settings.model.ICSettingEntry;
  */
 public class GCCBuildCommandParser extends AbstractBuildCommandParser implements ILanguageSettingsEditableProvider {
 	@SuppressWarnings("nls")
-	static final AbstractOptionParser[] optionParsers = {
+	static final AbstractOptionParser[] includeOptionParsers = {
 			new IncludePathOptionParser("-I\\s*(?<quote>[\"'])(.*)\\k<quote>", "$2"),
-			new IncludePathOptionParser("-I\\s*([^\\s\"']*)", "$1"),
+			new IncludePathOptionParser("-I\\s*([^\\s\"']*)", "$1"), };
+
+	@SuppressWarnings("nls")
+	static final AbstractOptionParser[] systemIncludeOptionParsers = {
 			new IncludePathOptionParser("-isystem\\s*(?<quote>[\"'])(.*)\\k<quote>", "$2"),
-			new IncludePathOptionParser("-isystem\\s*([^\\s\"']*)", "$1"),
+			new IncludePathOptionParser("-isystem\\s*([^\\s\"']*)", "$1"), };
+
+	@SuppressWarnings("nls")
+	static final AbstractOptionParser[] frameworkOptionParsers = {
 			new IncludePathOptionParser("-(F|(iframework))\\s*(?<quote>[\"'])(.*)\\k<quote>", "$4",
 					ICSettingEntry.FRAMEWORKS_MAC),
-			new IncludePathOptionParser("-(F|(iframework))\\s*([^\\s\"']*)", "$3", ICSettingEntry.FRAMEWORKS_MAC),
+			new IncludePathOptionParser("-(F|(iframework))\\s*([^\\s\"']*)", "$3", ICSettingEntry.FRAMEWORKS_MAC), };
+
+	@SuppressWarnings("nls")
+	static final AbstractOptionParser[] forceIncludeOptionParsers = {
 			new IncludeFileOptionParser("-include\\s*(?<quote>[\"'])(.*)\\k<quote>", "$2"),
-			new IncludeFileOptionParser("-include\\s*([^\\s\"']*)", "$1"),
+			new IncludeFileOptionParser("-include\\s*([^\\s\"']*)", "$1"), };
+
+	@SuppressWarnings("nls")
+	static final AbstractOptionParser[] defineOptionParsers = {
 			new MacroOptionParser("-D\\s*(?<quote>[\"'])([^=]*)(=(.*))?\\k<quote>", "$2", "$4"),
 			new MacroOptionParser("-D\\s*([^\\s=\"']*)=(\"\\\\(\")(.*?)\\\\\"\")", "$1", "$3$4$3"),
 			new MacroOptionParser("-D\\s*([^\\s=\"']*)=(?<quote>\\\\([\"']))(.*?)\\k<quote>", "$1", "$3$4$3"),
 			new MacroOptionParser("-D\\s*([^\\s=\"']*)=(?<quote>[\"'])(.*?)\\k<quote>", "$1", "$3"),
 			new MacroOptionParser("-D\\s*([^\\s=\"']*)=([^\\s\"']*)?", "$1", "$2"),
-			new MacroOptionParser("-D\\s*([^\\s=\"']*)", "$1", "1"),
-			new MacroOptionParser("-U\\s*([^\\s=\"']*)", "$1", ICSettingEntry.UNDEFINED),
+			new MacroOptionParser("-D\\s*([^\\s=\"']*)", "$1", "1"), };
+
+	@SuppressWarnings("nls")
+	static final AbstractOptionParser[] undefineOptionParsers = {
+			new MacroOptionParser("-U\\s*([^\\s=\"']*)", "$1", ICSettingEntry.UNDEFINED), };
+
+	@SuppressWarnings("nls")
+	static final AbstractOptionParser[] macrosOptionParsers = {
 			new MacroFileOptionParser("-imacros\\s*(?<quote>[\"'])(.*)\\k<quote>", "$2"),
-			new MacroFileOptionParser("-imacros\\s*([^\\s\"']*)", "$1"),
+			new MacroFileOptionParser("-imacros\\s*([^\\s\"']*)", "$1"), };
+
+	@SuppressWarnings("nls")
+	static final AbstractOptionParser[] libraryOptionParsers = {
 			new LibraryPathOptionParser("-L\\s*(?<quote>[\"'])(.*)\\k<quote>", "$2"),
 			new LibraryPathOptionParser("-L\\s*([^\\s\"']*)", "$1"),
 			new LibraryFileOptionParser("-l\\s*([^\\s\"']*)", "lib$1.a"), };
 
+	static final AbstractOptionParser[] emptyParsers = new AbstractOptionParser[0];
+
+	static final AbstractOptionParser[] optionParsers;
+	static {
+		List<AbstractOptionParser> parsers = new ArrayList<>(Arrays.asList(includeOptionParsers));
+		Collections.addAll(parsers, systemIncludeOptionParsers);
+		Collections.addAll(parsers, frameworkOptionParsers);
+		Collections.addAll(parsers, forceIncludeOptionParsers);
+		Collections.addAll(parsers, defineOptionParsers);
+		Collections.addAll(parsers, undefineOptionParsers);
+		Collections.addAll(parsers, macrosOptionParsers);
+		Collections.addAll(parsers, libraryOptionParsers);
+
+		optionParsers = parsers.toArray(new AbstractOptionParser[0]);
+	}
+
 	@Override
 	protected AbstractOptionParser[] getOptionParsers() {
 		return optionParsers;
 	}
 
+	@SuppressWarnings("nls")
+	@Override
+	protected AbstractOptionParser[] getOptionParsers(String optionToParse) {
+		if (optionToParse.length() <= 1) {
+			return emptyParsers;
+		}
+
+		// Skip -, we know it's there with the OPTIONS_PATTERN
+		String optionName = optionToParse.substring(1);
+
+		if (optionName.startsWith("I")) {
+			return includeOptionParsers;
+		}
+
+		if (optionName.startsWith("D")) {
+			return defineOptionParsers;
+		}
+
+		if (optionName.startsWith("l") || optionName.startsWith("L")) {
+			return libraryOptionParsers;
+		}
+
+		if (optionName.startsWith("i")) {
+			if (optionName.startsWith("include")) {
+				return forceIncludeOptionParsers;
+			}
+
+			if (optionName.startsWith("isystem")) {
+				return systemIncludeOptionParsers;
+			}
+
+			if (optionName.startsWith("imacros")) {
+				return macrosOptionParsers;
+			}
+
+			if (optionName.startsWith("iframework")) {
+				return frameworkOptionParsers;
+			}
+
+			return emptyParsers;
+		}
+
+		if (optionName.startsWith("F")) {
+			return frameworkOptionParsers;
+		}
+
+		if (optionName.startsWith("U")) {
+			return undefineOptionParsers;
+		}
+
+		return emptyParsers;
+	}
+
 	@Override
 	public GCCBuildCommandParser cloneShallow() throws CloneNotSupportedException {
 		return (GCCBuildCommandParser) super.cloneShallow();