bug 357442: Added $CYGWIN_HOME to cygwin toolchain detection algorithm

3 files changed, 170 insertions, 238 deletions

diff --git a/build/org.eclipse.cdt.managedbuilder.gnu.ui/src/org/eclipse/cdt/managedbuilder/gnu/cygwin/CygwinPathResolver.java b/build/org.eclipse.cdt.managedbuilder.gnu.ui/src/org/eclipse/cdt/managedbuilder/gnu/cygwin/CygwinPathResolver.java
index 8f2b5b7e781..f3e5dc9e034 100644
--- a/build/org.eclipse.cdt.managedbuilder.gnu.ui/src/org/eclipse/cdt/managedbuilder/gnu/cygwin/CygwinPathResolver.java
+++ b/build/org.eclipse.cdt.managedbuilder.gnu.ui/src/org/eclipse/cdt/managedbuilder/gnu/cygwin/CygwinPathResolver.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2005, 2010 Intel Corporation and others.
+ * Copyright (c) 2005, 2013 Intel Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -9,6 +9,7 @@
  *     Intel Corporation - Initial API and implementation
  *     Enrico Ehrich - http://bugs.eclipse.org/233866
  *     Marc-Andre Laperle - fix for Cygwin GCC is Not detected (bug 303900)
+ *     Andrew Gvozdev - changes to recognize $CYGWIN_HOME
  *******************************************************************************/
 package org.eclipse.cdt.managedbuilder.gnu.cygwin;
 
@@ -19,9 +20,8 @@ import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.util.ArrayList;
 
-import org.eclipse.cdt.core.CCorePlugin;
 import org.eclipse.cdt.core.envvar.IEnvironmentVariable;
-import org.eclipse.cdt.core.settings.model.util.CDataUtil;
+import org.eclipse.cdt.internal.core.Cygwin;
 import org.eclipse.cdt.managedbuilder.core.IBuildPathResolver;
 import org.eclipse.cdt.managedbuilder.core.IConfiguration;
 import org.eclipse.cdt.managedbuilder.core.ManagedBuildManager;
@@ -30,40 +30,35 @@ import org.eclipse.cdt.utils.PathUtil;
 import org.eclipse.cdt.utils.WindowsRegistry;
 import org.eclipse.cdt.utils.spawner.ProcessFactory;
 import org.eclipse.core.runtime.IPath;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Status;
 
 /**
  * @noextend This class is not intended to be subclassed by clients.
  */
 public class CygwinPathResolver implements IBuildPathResolver {
-	private static final String DEFAULT_ROOT = "C:\\cygwin"; //$NON-NLS-1$
-	private static final String TOOL = "/cygpath -w -p "; //$NON-NLS-1$
-	private static final char BS = '\\';
-	private static final char SLASH = '/';
+	private static final String ENV_PATH = "PATH"; //$NON-NLS-1$
+	private static final String DELIMITER_UNIX = ":";    //$NON-NLS-1$
+	private static final String DELIMITER_WIN  = ";";    //$NON-NLS-1$
+
 	private static final String PROPERTY_OS_NAME = "os.name"; //$NON-NLS-1$
-	private static final String PROPERTY_OS_VALUE = "windows";//$NON-NLS-1$
-	private static final String SP = " ";         //$NON-NLS-1$
-	private static final String REGISTRY_KEY_SETUP = "SOFTWARE\\Cygwin\\setup"; //$NON-NLS-1$
-	private static final String REGISTRY_KEY_SETUP_WIN64 = "SOFTWARE\\Wow6432Node\\Cygwin\\setup"; //$NON-NLS-1$
+	private static final String OS_WINDOWS = "windows";//$NON-NLS-1$
+	private static final char SLASH = '/';
+	private static final char BACKSLASH = '\\';
+
+	private static final String CYGPATH_PATH_LIST_TO_WINDOWS = "cygpath -w -p "; //$NON-NLS-1$
+
 	// note that in Cygwin 1.7 the mount point storage has been moved out of the registry
 	private static final String REGISTRY_KEY_MOUNTS = "SOFTWARE\\Cygnus Solutions\\Cygwin\\mounts v2\\"; //$NON-NLS-1$
 	private static final String PATH_NAME = "native";   //$NON-NLS-1$
-	private static final String SSLASH = "/";           //$NON-NLS-1$
-	private static final String BSLASH = "\\\\";        //$NON-NLS-1$
 	private static final String BINPATTERN = "/usr/bin"; //$NON-NLS-1$
 	private static final String BINPATTERN_ALTERNATE = "/bin"; //$NON-NLS-1$
 	private static final String ETCPATTERN = "/etc";     //$NON-NLS-1$
-	private static final String ROOTPATTERN = SSLASH;
-	private static final String DELIMITER_UNIX = ":";    //$NON-NLS-1$
-	private static final String DELIMITER_WIN  = ";";    //$NON-NLS-1$
+
 	private static final String GCC_VERSION_CMD  = "gcc --version";    //$NON-NLS-1$
 	private static final String MINGW_SPECIAL = "mingw ";    //$NON-NLS-1$
 	private static final String CYGWIN_SPECIAL = "cygwin ";    //$NON-NLS-1$
 
-	private static String envPathValueCached = null;
-	private static String binCygwin  = null;
-	private static String rootCygwin = null;
-	private static String etcCygwin = null;
-
 	@Override
 	public String[] resolveBuildPaths(int pathType, String variableName, String variableValue, IConfiguration configuration) {
 		if(!isWindows()) {
@@ -72,58 +67,66 @@ public class CygwinPathResolver implements IBuildPathResolver {
 			return variableValue.split(DELIMITER_WIN);
 		}
 
-		String[] result = variableValue.split(DELIMITER_UNIX);
-		String exePath = getBinPath();
-		if (exePath == null) {
-			return result; // no changes
-		}
-		File file = new File(exePath);
-		if (!file.exists() || !file.isDirectory()) {
-			return result; // no changes
-		}
-		String s = exePath + TOOL + variableValue;
-		String[] lines = exec(s, configuration);
+		String[] lines = executeInConfigurationContext(CYGPATH_PATH_LIST_TO_WINDOWS + variableValue, configuration);
 		if (lines != null && lines.length > 0) {
-			result = lines[0].replace(BS,SLASH).split(DELIMITER_WIN);
+			String pathList = lines[0].replace(BACKSLASH, SLASH);
+			return pathList.split(DELIMITER_WIN);
 		}
-		return result;
+
+		return variableValue.split(DELIMITER_UNIX);
 	}
 
 	/**
-	 * returns "/etc" path in Windows format
+	 * @return "/etc" path in Windows format for workspace.
+	 * @deprecated. Deprecated as of CDT 8.2. Note that Cygwin root path in general may depend on configuration.
 	 *
 	 * If you use this do not cache results to ensure user preferences are accounted for.
 	 * Please rely on internal caching.
 	 */
+	@Deprecated
 	public static String getEtcPath() {
-		findPaths();
+		String etcCygwin = getPathFromRoot(ETCPATTERN);
+		// Try to find the paths in SOFTWARE\\Cygnus Solutions
+		if(etcCygwin == null) {
+			etcCygwin = readValueFromRegistry(REGISTRY_KEY_MOUNTS + ETCPATTERN, PATH_NAME);
+		}
 		return etcCygwin;
 	}
 
 	/**
-	 * returns "/usr/bin" path in Windows format
+	 * @return "/usr/bin" path in Windows format for workspace.
+	 * @deprecated. Deprecated as of CDT 8.2. Note that Cygwin root path in general may depend on configuration.
 	 *
 	 * If you use this do not cache results to ensure user preferences are accounted for.
 	 * Please rely on internal caching.
 	 */
+	@Deprecated
 	public static String getBinPath() {
-		findPaths();
+		String binCygwin = getPathFromRoot(BINPATTERN);
+		if(binCygwin == null) {
+			binCygwin = getPathFromRoot(BINPATTERN_ALTERNATE);
+		}
+		// Try to find the paths in SOFTWARE\\Cygnus Solutions
+		if(binCygwin == null) {
+			binCygwin = readValueFromRegistry(REGISTRY_KEY_MOUNTS + BINPATTERN, PATH_NAME);
+		}
 		return binCygwin;
 	}
 
 	/**
-	 * returns Cygwin root ("/") path in Windows format
+	 * @return Cygwin root ("/") path in Windows format for workspace.
+	 * @deprecated. Deprecated as of CDT 8.2. Note that Cygwin root path in general may depend on configuration.
 	 *
 	 * If you use this do not cache results to ensure user preferences are accounted for.
 	 * Please rely on internal caching.
 	 */
+	@Deprecated
 	public static String getRootPath() {
-		findPaths();
-		return rootCygwin;
+		return Cygwin.getCygwinHome();
 	}
 
 	public static boolean isWindows() {
-		return (System.getProperty(PROPERTY_OS_NAME).toLowerCase().startsWith(PROPERTY_OS_VALUE));
+		return (System.getProperty(PROPERTY_OS_NAME).toLowerCase().startsWith(OS_WINDOWS));
 	}
 
 	/**
@@ -136,146 +139,117 @@ public class CygwinPathResolver implements IBuildPathResolver {
 	 */
 	private static String readValueFromRegistry(String key, String name) {
 		WindowsRegistry registry = WindowsRegistry.getRegistry();
-		if (null != registry) {
-			String s = registry.getCurrentUserValue(key, name);
-			if(s == null)
-				s = registry.getLocalMachineValue(key, name);
-
-			if (s != null)
-				return (s.replaceAll(BSLASH, SSLASH));
+		if (registry != null) {
+			String value = registry.getCurrentUserValue(key, name);
+			if (value == null) {
+				value = registry.getLocalMachineValue(key, name);
+			}
+			if (value != null) {
+				return value.replace(BACKSLASH, SLASH);
+			}
 		}
 		return null;
 	}
 
 	/**
-	 *  Returns the absolute path of the pattern by
-	 *  simply appending the pattern to the root
+	 * Returns the absolute path of the pattern by simply appending the relativePath to the root.
 	 *
-	 * @param pattern The pattern to find
-	 * @return The absolute path to the pattern or null if pattern is not found
+	 * @param relativePath - the pattern to find.
+	 * @return The absolute path to the pattern or {@code null} if path does not exist.
 	 */
-	private static String getValueFromRoot(String pattern) {
+	private static String getPathFromRoot(String relativePath) {
+		String rootCygwin = Cygwin.getCygwinHome();
 		if (rootCygwin != null) {
-			String path = rootCygwin + pattern;
+			String path = rootCygwin + relativePath;
 			File file = new File(path);
-			if (file.exists() && file.isDirectory())
-				return (path.replaceAll(BSLASH, SSLASH));
-			else
-				return null;
+			if (file.exists() && file.isDirectory()) {
+				return path.replace(BACKSLASH, SLASH);
+			}
 		}
-
 		return null;
 	}
 
 	/**
-	 * Returns the absolute path to cygwin's root
+	 * Resolve and return full path to program in context of configuration.
 	 *
-	 * @return The absolute path to cygwin's root or null if not found
+	 * @param program - program to resolve.
+	 * @param cfg - configuration context.
+	 * @return absolute path to program.
 	 */
-	private static String findRoot(String paths) {
-		String rootValue = null;
-
-		// 1. Look in PATH values. Look for bin\cygwin1.dll
-		IPath location = PathUtil.findProgramLocation("cygwin1.dll", paths); //$NON-NLS-1$
-		if (location!=null) {
-			rootValue = location.removeLastSegments(2).toOSString();
-		}
-
-		// 2. Try to find the root dir in SOFTWARE\Cygwin\setup
-		if(rootValue == null) {
-			rootValue = readValueFromRegistry(REGISTRY_KEY_SETUP, "rootdir"); //$NON-NLS-1$
-		}
-
-		// 3. Try to find the root dir in SOFTWARE\Wow6432Node\Cygwin\setup
-		if(rootValue == null) {
-			rootValue = readValueFromRegistry(REGISTRY_KEY_SETUP_WIN64, "rootdir"); //$NON-NLS-1$
-		}
-
-		// 4. Try to find the root dir in SOFTWARE\Cygnus Solutions
-		if (rootValue == null) {
-			rootValue = readValueFromRegistry(REGISTRY_KEY_MOUNTS + ROOTPATTERN, PATH_NAME);
-		}
-
-		// 5. Try the default Cygwin install dir
-		if(rootValue == null) {
-			File file = new File(DEFAULT_ROOT);
-			if (file.exists() && file.isDirectory())
-				rootValue = DEFAULT_ROOT;
+	private static String resolveProgram(String program, IConfiguration cfg) {
+		String envPathValue = null;
+		try {
+			IEnvironmentVariable envPathVar = ManagedBuildManager.getEnvironmentVariableProvider().getVariable(ENV_PATH, cfg, true);
+			if (envPathVar != null) {
+				envPathValue = envPathVar.getValue();
+				IPath progPath = PathUtil.findProgramLocation(program, envPathValue);
+				if (progPath != null) {
+					program = progPath.toOSString();
+				}
+				// this resolves cygwin symbolic links
+				program = Cygwin.cygwinToWindowsPath(program, envPathValue);
+			}
+		} catch (Exception e) {
+			GnuUIPlugin.getDefault().log(new Status(IStatus.WARNING, GnuUIPlugin.PLUGIN_ID, "Problem trying to find program [" + program + "] in $PATH=[" + envPathValue + "]", e));
 		}
-
-		if(rootValue != null)
-			rootValue = rootValue.replaceAll(BSLASH, SSLASH);
-
-		return rootValue;
+		return program;
 	}
 
 	/**
-	 * Finds Cygwin's paths and sets corresponding properties.
+	 * Return environment in envp format, see {@link Runtime#exec(String, String[])}.
+	 *
+	 * @param cfg - configuration.
+	 * @return environment as array of strings in format name=value.
 	 */
-	private static synchronized void findPaths() {
-		if (!isWindows()) {
-			return;
+	private static String[] getEnvp(IConfiguration cfg) {
+		IEnvironmentVariable vars[] = ManagedBuildManager.getEnvironmentVariableProvider().getVariables(cfg,true);
+		String envp[] = new String[vars.length];
+		for(int i = 0; i < envp.length; i++) {
+			envp[i] = vars[i].getName() +'=';
+			String value = vars[i].getValue();
+			if(value != null)
+				envp[i] += value;
 		}
-
-		IEnvironmentVariable varPath = CCorePlugin.getDefault().getBuildEnvironmentManager().getVariable("PATH", null, true); //$NON-NLS-1$
-		String envPathValue = varPath != null ? varPath.getValue() : null;
-
-		if (CDataUtil.objectsEqual(envPathValue, envPathValueCached)) {
-			return;
-		}
-
-		etcCygwin  = null;
-		binCygwin  = null;
-		rootCygwin = null;
-
-		rootCygwin = findRoot(envPathValue);
-
-		// 1. Try to find the paths by appending the patterns to the root dir
-		etcCygwin = getValueFromRoot(ETCPATTERN);
-		binCygwin = getValueFromRoot(BINPATTERN);
-		if(binCygwin == null)
-			binCygwin = getValueFromRoot(BINPATTERN_ALTERNATE);
-
-		// 2. Try to find the paths in SOFTWARE\\Cygnus Solutions
-		if(etcCygwin == null)
-			etcCygwin = readValueFromRegistry(REGISTRY_KEY_MOUNTS + ETCPATTERN, PATH_NAME);
-		if(binCygwin == null)
-			binCygwin = readValueFromRegistry(REGISTRY_KEY_MOUNTS + BINPATTERN, PATH_NAME);
-
-		envPathValueCached = envPathValue;
+		return envp;
 	}
 
-	private static String[] exec(String cmd, IConfiguration cfg) {
+	/**
+	 * Execute command taking in account configuration environment.
+	 *
+	 * @param cmd - command to execute.
+	 * @param cfg - configuration context.
+	 * @return command output as string array.
+	 */
+	private static String[] executeInConfigurationContext(String cmd, IConfiguration cfg) {
+		String[] args = cmd.split(" "); //$NON-NLS-1$
+		args[0] = resolveProgram(args[0], cfg);
+
+		String[] result = null;
 		try {
-			IEnvironmentVariable vars[] = ManagedBuildManager.getEnvironmentVariableProvider().getVariables(cfg,true);
-			String env[] = new String[vars.length];
-			for(int i = 0; i < env.length; i++) {
-				env[i] = vars[i].getName() + "="; //$NON-NLS-1$
-				String value = vars[i].getValue();
-				if(value != null)
-					env[i] += value;
-			}
-			Process proc = ProcessFactory.getFactory().exec(cmd.split(SP), env);
+			String[] envp = getEnvp(cfg);
+			Process proc = ProcessFactory.getFactory().exec(args, envp);
 			if (proc != null) {
-
 				InputStream ein = proc.getInputStream();
-				BufferedReader d1 = new BufferedReader(new InputStreamReader(ein));
-				ArrayList<String> ls = new ArrayList<String>(10);
-				String s;
-				while ((s = d1.readLine() ) != null ) {
-					ls.add(s);
+				try {
+					BufferedReader d1 = new BufferedReader(new InputStreamReader(ein));
+					ArrayList<String> ls = new ArrayList<String>(10);
+					String s;
+					while ((s = d1.readLine()) != null ) {
+						ls.add(s);
+					}
+					result = ls.toArray(new String[0]);
+				} finally {
+					ein.close();
 				}
-				ein.close();
-				return ls.toArray(new String[0]);
 			}
 		} catch (IOException e) {
-			GnuUIPlugin.getDefault().log(e);
+			GnuUIPlugin.getDefault().log(new Status(IStatus.ERROR, GnuUIPlugin.PLUGIN_ID, "Error executing program [" +cmd + "]", e));
 		}
-		return null;
+		return result;
 	}
 
 	public static boolean isMinGW(IConfiguration cfg) {
-		String versionInfo[] = exec(GCC_VERSION_CMD, cfg);
+		String versionInfo[] = executeInConfigurationContext(GCC_VERSION_CMD, cfg);
 		if(versionInfo != null) {
 			for(int i = 0; i < versionInfo.length; i++) {
 				if(versionInfo[i].indexOf(MINGW_SPECIAL) != -1)
diff --git a/build/org.eclipse.cdt.managedbuilder.gnu.ui/src/org/eclipse/cdt/managedbuilder/gnu/cygwin/GnuCygwinConfigurationEnvironmentSupplier.java b/build/org.eclipse.cdt.managedbuilder.gnu.ui/src/org/eclipse/cdt/managedbuilder/gnu/cygwin/GnuCygwinConfigurationEnvironmentSupplier.java
index ae08fcf841d..5b659ead2d2 100644
--- a/build/org.eclipse.cdt.managedbuilder.gnu.ui/src/org/eclipse/cdt/managedbuilder/gnu/cygwin/GnuCygwinConfigurationEnvironmentSupplier.java
+++ b/build/org.eclipse.cdt.managedbuilder.gnu.ui/src/org/eclipse/cdt/managedbuilder/gnu/cygwin/GnuCygwinConfigurationEnvironmentSupplier.java
@@ -1,33 +1,38 @@
 /*******************************************************************************
- * Copyright (c) 2005, 2011 Intel Corporation and others.
+ * Copyright (c) 2005, 2012 Intel Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
- * Intel Corporation - Initial API and implementation
+ *     Intel Corporation - Initial API and implementation
+ *     Andrew Gvozdev    - Ability to use different Cygwin versions in different cfg
  *******************************************************************************/
 package org.eclipse.cdt.managedbuilder.gnu.cygwin;
 
+import org.eclipse.cdt.core.CCorePlugin;
+import org.eclipse.cdt.core.envvar.IEnvironmentVariable;
+import org.eclipse.cdt.internal.core.Cygwin;
 import org.eclipse.cdt.managedbuilder.core.IConfiguration;
 import org.eclipse.cdt.managedbuilder.envvar.IBuildEnvironmentVariable;
 import org.eclipse.cdt.managedbuilder.envvar.IConfigurationEnvironmentVariableSupplier;
 import org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableProvider;
 import org.eclipse.cdt.managedbuilder.internal.envvar.BuildEnvVar;
+import org.eclipse.core.runtime.IPath;
+import org.eclipse.core.runtime.Path;
 
 /**
  * @noextend This class is not intended to be subclassed by clients.
  */
 public class GnuCygwinConfigurationEnvironmentSupplier implements IConfigurationEnvironmentVariableSupplier {
-	private static final String PATH = "PATH"; //$NON-NLS-1$
-	private static final String DELIMITER_UNIX = ":"; //$NON-NLS-1$
-	private static final String PROPERTY_DELIMITER = "path.separator"; //$NON-NLS-1$
-	private static final String PROPERTY_OSNAME = "os.name"; //$NON-NLS-1$
+	private static final String ENV_PATH = "PATH"; //$NON-NLS-1$
+	private static final String ENV_LANG = "LANG"; //$NON-NLS-1$
+	private static final String ENV_LC_ALL = "LC_ALL"; //$NON-NLS-1$
+	private static final String ENV_LC_MESSAGES = "LC_MESSAGES"; //$NON-NLS-1$
 
-	private static final String LANG = "LANG"; //$NON-NLS-1$
-	private static final String LC_ALL = "LC_ALL"; //$NON-NLS-1$
-	private static final String LC_MESSAGES = "LC_MESSAGES"; //$NON-NLS-1$
+	private static final String PROPERTY_OSNAME = "os.name"; //$NON-NLS-1$
+	private static final String BACKSLASH = java.io.File.separator;
 
 	@Override
 	public IBuildEnvironmentVariable getVariable(String variableName, IConfiguration configuration, IEnvironmentVariableProvider provider) {
@@ -39,19 +44,33 @@ public class GnuCygwinConfigurationEnvironmentSupplier implements IConfiguration
 			return null;
 		}
 
-		if (variableName.equalsIgnoreCase(PATH)) {
-			String p = CygwinPathResolver.getBinPath();
-			if (p != null) {
-				return new BuildEnvVar(PATH, p.replace('/','\\'), IBuildEnvironmentVariable.ENVVAR_PREPEND, System.getProperty(PROPERTY_DELIMITER, DELIMITER_UNIX));
+		if (variableName.equalsIgnoreCase(ENV_PATH)) {
+			@SuppressWarnings("nls")
+			String path = "${" + Cygwin.ENV_CYGWIN_HOME + "}" + BACKSLASH + "bin";
+			return new BuildEnvVar(ENV_PATH, path, IBuildEnvironmentVariable.ENVVAR_PREPEND);
+
+		} else if (variableName.equals(Cygwin.ENV_CYGWIN_HOME)) {
+			String home = Cygwin.getCygwinHome();
+			// If the variable is not defined still show it in the environment variables list as a hint to user
+			if (home == null) {
+				home = ""; //$NON-NLS-1$
+			}
+			IPath homePath = new Path(home);
+			IEnvironmentVariable varCygwinHome = CCorePlugin.getDefault().getBuildEnvironmentManager().getVariable(Cygwin.ENV_CYGWIN_HOME, null, false);
+			if (varCygwinHome == null || (!homePath.equals(new Path(varCygwinHome.getValue())))) {
+				// Contribute if the variable does not already come from workspace environment
+				return new BuildEnvVar(Cygwin.ENV_CYGWIN_HOME, homePath.toOSString());
 			}
-		} else if (variableName.equalsIgnoreCase(LANG)) {
+			return null;
+
+		} else if (variableName.equalsIgnoreCase(ENV_LANG)) {
 			// Workaround for not being able to select encoding for CDT console -> change codeset to Latin1
-			String langValue = System.getenv(LANG);
+			String langValue = System.getenv(ENV_LANG);
 			if (langValue == null || langValue.length() == 0) {
-				langValue = System.getenv(LC_ALL);
+				langValue = System.getenv(ENV_LC_ALL);
 			}
 			if (langValue == null || langValue.length() == 0) {
-				langValue = System.getenv(LC_MESSAGES);
+				langValue = System.getenv(ENV_LC_MESSAGES);
 			}
 			if (langValue != null && langValue.length() > 0) {
 				// langValue is [language[_territory][.codeset][@modifier]], i.e. "en_US.UTF-8@dict"
@@ -61,21 +80,17 @@ public class GnuCygwinConfigurationEnvironmentSupplier implements IConfiguration
 			} else {
 				langValue = "C.ISO-8859-1"; //$NON-NLS-1$
 			}
-
-			return new BuildEnvVar(LANG, langValue);
+			return new BuildEnvVar(ENV_LANG, langValue);
 		}
 		return null;
 	}
 
 	@Override
 	public IBuildEnvironmentVariable[] getVariables(IConfiguration configuration, IEnvironmentVariableProvider provider) {
-		IBuildEnvironmentVariable varLang = getVariable(LANG, configuration, provider);
-		IBuildEnvironmentVariable varPath = getVariable(PATH, configuration, provider);
+		IBuildEnvironmentVariable varHome = getVariable(Cygwin.ENV_CYGWIN_HOME, configuration, provider);
+		IBuildEnvironmentVariable varLang = getVariable(ENV_LANG, configuration, provider);
+		IBuildEnvironmentVariable varPath = getVariable(ENV_PATH, configuration, provider);
 
-		if (varPath != null) {
-			return new IBuildEnvironmentVariable[] {varLang, varPath};
-		} else {
-			return new IBuildEnvironmentVariable[] {varLang};
-		}
+		return new IBuildEnvironmentVariable[] {varHome, varLang, varPath};
 	}
 }
diff --git a/build/org.eclipse.cdt.managedbuilder.gnu.ui/src/org/eclipse/cdt/managedbuilder/gnu/cygwin/IsGnuCygwinToolChainSupported.java b/build/org.eclipse.cdt.managedbuilder.gnu.ui/src/org/eclipse/cdt/managedbuilder/gnu/cygwin/IsGnuCygwinToolChainSupported.java
index a2d2050338a..9a2fd648827 100644
--- a/build/org.eclipse.cdt.managedbuilder.gnu.ui/src/org/eclipse/cdt/managedbuilder/gnu/cygwin/IsGnuCygwinToolChainSupported.java
+++ b/build/org.eclipse.cdt.managedbuilder.gnu.ui/src/org/eclipse/cdt/managedbuilder/gnu/cygwin/IsGnuCygwinToolChainSupported.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2005, 2010 Intel Corporation and others.
+ * Copyright (c) 2005, 2013 Intel Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -7,85 +7,28 @@
  *
  * Contributors:
  * Intel Corporation - Initial API and implementation
+ * Andrew Gvozdev    - Ability to use different Cygwin versions in different configurations
  *******************************************************************************/
 package org.eclipse.cdt.managedbuilder.gnu.cygwin;
 
-import java.io.BufferedReader;
-import java.io.File;
-import java.io.FileNotFoundException;
-import java.io.FileReader;
-import java.io.IOException;
-
-import org.eclipse.cdt.core.settings.model.util.CDataUtil;
+import org.eclipse.cdt.internal.core.Cygwin;
 import org.eclipse.cdt.managedbuilder.core.IManagedIsToolChainSupported;
 import org.eclipse.cdt.managedbuilder.core.IToolChain;
+import org.eclipse.cdt.managedbuilder.internal.envvar.EnvironmentVariableManagerToolChain;
 import org.osgi.framework.Version;
 
 /**
  * This class implements the IManagedIsToolChainSupported for the Gnu Cygwin tool-chain
- * The class is NOT used currently, because currently the gnu cygwin tool-chain
- * is intended to be used not only with Cygwin, but with MinGW also, and there is no
- * correct way of determining whether the appropriate packages are installed for MinGW.
- *
- * For the future MBS/CDT versions we might create the separate tool-chain/configuration/project-type
- * for the MinGW and define a set of converters using the tool-chain converter mechanism that MBS will provide,
- * that would convert the CygWin to the MinGW projects/tool-chains, and vice a versa.
  *
  * @noextend This class is not intended to be subclassed by clients.
  */
 public class IsGnuCygwinToolChainSupported implements IManagedIsToolChainSupported {
-	private static final String[] CHECKED_NAMES = {"gcc", "binutils", "make"};  //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
+	private static final String ENV_PATH = "PATH"; //$NON-NLS-1$
 
-	private static String etcCygwinCached = null;
-	private static boolean toolchainIsSupported = false;
-
-	/**
-	 * @since 8.0
-	 */
 	@Override
 	public boolean isSupported(IToolChain toolChain, Version version, String instance) {
-		String etcCygwin = CygwinPathResolver.getEtcPath();
-		if (CDataUtil.objectsEqual(etcCygwin, etcCygwinCached)) {
-			return toolchainIsSupported;
-		}
-
-		toolchainIsSupported = etcCygwin != null && arePackagesInstalled(etcCygwin);
-		etcCygwinCached = etcCygwin;
-
-		return toolchainIsSupported;
+		String envPath = EnvironmentVariableManagerToolChain.getDefault().getVariableInConfigurationContext(ENV_PATH, toolChain, true);
+		return Cygwin.isAvailable(envPath);
 	}
 
-	/**
-	 * Returns true if all required packages are installed, see CHECKED_NAMES for a list of packages. Cygwin
-	 * maintains a list of packages in /etc/setup/installed.db so we look for packages in this file.
-	 *
-	 * @param etcCygwin the absolute path of /etc containing /setup/installed.db
-	 * @return true if the packages specified in CHECKED_NAMES are installed
-	 */
-	private boolean arePackagesInstalled(String etcCygwin) {
-		boolean arePackagesInstalled = false;
-		File file = new File(etcCygwin + "/setup/installed.db"); //$NON-NLS-1$
-		try {
-			BufferedReader data = new BufferedReader(new FileReader(file));
-
-			// All required package names should be found
-			boolean[] found = new boolean[CHECKED_NAMES.length];
-			String s;
-			while ((s = data.readLine()) != null ) {
-				for (int j = 0; j < CHECKED_NAMES.length; j++) {
-					if (s.startsWith(CHECKED_NAMES[j])) {
-						found[j] = true;
-					}
-				}
-			}
-			arePackagesInstalled = true;
-			for (int j = 0; j < CHECKED_NAMES.length; j++) {
-				arePackagesInstalled &= found[j];
-			}
-			data.close();
-		} catch (FileNotFoundException e) {
-		} catch (IOException e) {
-		}
-		return arePackagesInstalled;
-	}
 }