Fix for the compiler path in compile_commands.json file

Compiler path was wrongly created when anything was set on the "Prefix"
option from "Cross Settings". The code needs to check if anything is set
there before creating the default path for the compiler.

Author: alicetrifu

build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/jsoncdb/generator/CompilationDatabaseGenerator.java

@@ -70,7 +70,7 @@ public final class CompilationDatabaseGenerator {
 	 * Checked on each build
 	 * Used before we look up the environment
 	 */
-	private Map<ITool, String> toolMap = new HashMap<>();
+	private Map<String, String> toolMap = new HashMap<>();
 	private IProject project;
 	private IConfiguration configuration;
 	private ICSourceEntry[] srcEntries;
@@ -229,10 +229,10 @@ private List<CompilationDatabaseInformation> populateObjList(IProject project, I
 						outputLocation + "", inputStrings, sourceLocation, outputLocation); //$NON-NLS-1$
 
 				IBuildMacroProvider provider = ManagedBuildManager.getBuildMacroProvider();
-				String compilerName = CompilationDatabaseGenerator.getCompilerName(tool);
 				String commandLine = cmdLInfo.getCommandLine();
+				String compilerName = CompilationDatabaseGenerator.getCompilerName(commandLine);
 				commandLine = commandLine.replace(compilerName, "").trim(); //$NON-NLS-1$
-				String compilerPath = findCompilerInPath(tool, config);
+				String compilerPath = findCompilerInPath(tool, config, compilerName);
 				String resolvedOptionFileContents;
 				if (compilerPath != null && !compilerPath.isEmpty()) {
 					resolvedOptionFileContents = provider.resolveValueToMakefileFormat(compilerPath + " " + commandLine, //$NON-NLS-1$
@@ -438,15 +438,15 @@ public boolean visit(IResourceProxy proxy) throws CoreException {
 
 	}
 
-	private String findCompilerInPath(ITool tool, IConfiguration config) {
-		if (toolMap.containsKey(tool)) {
-			return "\"" + toolMap.get(tool) + "\""; //$NON-NLS-1$//$NON-NLS-2$
+	private String findCompilerInPath(ITool tool, IConfiguration config, String compilerName) {
+		String cacheKey = tool + " " + compilerName; //$NON-NLS-1$
+		if (toolMap.containsKey(cacheKey)) {
+			return "\"" + toolMap.get(cacheKey) + "\""; //$NON-NLS-1$//$NON-NLS-2$
 		}
-		String compilerName = CompilationDatabaseGenerator.getCompilerName(tool);
 		File pathToCompiler = new File(compilerName);
 
 		if (pathToCompiler.isAbsolute()) {
-			toolMap.put(tool, compilerName);
+			toolMap.put(cacheKey, compilerName);
 			return "\"" + compilerName + "\""; //$NON-NLS-1$ //$NON-NLS-2$
 		}
 		ICConfigurationDescription cfg = ManagedBuildManager.getDescriptionForConfiguration(config);
@@ -458,7 +458,7 @@ private String findCompilerInPath(ITool tool, IConfiguration config) {
 				IPath resolvedPath = PathUtil.findProgramLocation(compilerName, variable.getValue());
 				if (resolvedPath != null) {
 					String path = resolvedPath.toString();
-					toolMap.put(tool, path);
+					toolMap.put(cacheKey, path);
 					return "\"" + path + "\""; //$NON-NLS-1$ //$NON-NLS-2$
 				} else {
 					return null; // Only one PATH so can exit early
@@ -469,9 +469,8 @@ private String findCompilerInPath(ITool tool, IConfiguration config) {
 		return null;
 	}
 
-	private static String getCompilerName(ITool tool) {
-		String compilerCommand = tool.getToolCommand();
-		String[] arguments = CommandLineUtil.argumentsToArray(compilerCommand);
+	private static String getCompilerName(String commandLine) {
+		String[] arguments = CommandLineUtil.argumentsToArray(commandLine);
 		if (arguments.length == 0) {
 			return ""; //$NON-NLS-1$
 		}