[BUG] [JSR-199] ECJ cannot resolve JPMS modules if using a user-provided

file manager

+ change to 1 ClasspathJsr199 per module
+ test with two module dependencies (one auto, one regular)

Fixes eclipse-jdt#958

org.eclipse.jdt.compiler.tool.tests/resources/module_locations/GH958_2/module-info.java

@@ -0,0 +1,4 @@
+module GH958_2 {
+    requires GH958_mod;
+    requires org.example.adder;
+}

org.eclipse.jdt.compiler.tool.tests/resources/module_locations/GH958_2/org/example2/Main.java

@@ -0,0 +1,13 @@
+package org.example2;
+
+import org.example.regular.Foo;
+import org.example.adder.Adder;
+
+public class Main {
+	Foo foo;
+    public static void main(String[] args) {
+        int a = 123;
+        int b = 456;
+        System.out.println(new Adder().add(a, b));
+    }
+}

org.eclipse.jdt.compiler.tool.tests/src/org/eclipse/jdt/compiler/tool/tests/CompilerToolJava9Tests.java

@@ -991,15 +991,41 @@ public static JavaFileManager demote(JavaFileManager fileManager) {
 					);
 		}
 	}
-	public void testGH954() throws Exception {
+	public void testGH958() throws Exception {
 		File classOutput = new File(_tmpFolder);
 		JavaCompiler compiler = new EclipseCompiler();
 		StandardJavaFileManager standardFileManager = compiler.getStandardFileManager(null, null, null);
 
-		List<File> classPath = List.of(new File("resources/module_locations/automod_GH954.jar"));
-		List<File> sourcePath = List.of(new File("resources/module_locations/GH954"));
-		standardFileManager.setLocation(StandardLocation.CLASS_PATH, classPath);
-		standardFileManager.setLocation(StandardLocation.MODULE_PATH, classPath);
+		List<File> modulePath = List.of(new File("resources/module_locations/GH958_automod.jar"));
+		List<File> sourcePath = List.of(new File("resources/module_locations/GH958"));
+		standardFileManager.setLocation(StandardLocation.MODULE_PATH, modulePath);
+		standardFileManager.setLocation(StandardLocation.SOURCE_PATH, sourcePath);
+		standardFileManager.setLocation(StandardLocation.CLASS_OUTPUT, List.of(classOutput));
+
+		// Make ECJ think we don't inherit StandardJavaFileManager by wrapping it.
+		JavaFileManager demotedFileManager = DemotingFileManagerProxy.demote(standardFileManager);
+		Iterable<JavaFileObject> compilationUnits = demotedFileManager.list(StandardLocation.SOURCE_PATH, "", Set.of(JavaFileObject.Kind.SOURCE), true);
+
+		CompilationTask task = compiler.getTask(
+				null,
+				demotedFileManager,
+				null,
+				List.of("--release", "11", "-verbose"),
+				List.of(),
+				compilationUnits
+		);
+
+		assertTrue(task.call());
+	}
+	public void testGH958_2modules() throws Exception {
+		File classOutput = new File(_tmpFolder);
+		JavaCompiler compiler = new EclipseCompiler();
+		StandardJavaFileManager standardFileManager = compiler.getStandardFileManager(null, null, null);
+
+		List<File> modulesPath = List.of(new File("resources/module_locations/GH958_automod.jar"),
+											new File("resources/module_locations/GH958_mod.jar"));
+		List<File> sourcePath = List.of(new File("resources/module_locations/GH958_2"));
+		standardFileManager.setLocation(StandardLocation.MODULE_PATH, modulesPath);
 		standardFileManager.setLocation(StandardLocation.SOURCE_PATH, sourcePath);
 		standardFileManager.setLocation(StandardLocation.CLASS_OUTPUT, List.of(classOutput));
 

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/batch/ClasspathJsr199.java

@@ -27,7 +27,6 @@
 import java.util.List;
 import java.util.Set;
 import javax.tools.JavaFileManager;
-import javax.tools.JavaFileManager.Location;
 import javax.tools.JavaFileObject;
 import org.eclipse.jdt.core.compiler.CharOperation;
 import org.eclipse.jdt.internal.compiler.batch.FileSystem.Classpath;
@@ -160,20 +159,12 @@ public char[][][] findTypeNames(String aQualifiedPackageName, String moduleName)
 	public void initialize() throws IOException {
 		if (this.jrt != null) {
 			this.jrt.initialize();
-		} else if (this.location.isModuleOrientedLocation()) {
-			Iterable<Set<Location>> locationsForModules = this.fileManager.listLocationsForModules(this.location);
-			for (Set<Location> locs: locationsForModules) {
-				for (Location loc : locs) {
-					if (loc instanceof LocationWrapper wrapper) {
-						for (Path locPath : wrapper.getPaths()) {
-							File file = locPath.toFile();
-							IModule mod = ModuleFinder.scanForModule(this, file, null, true, null);
-							if (mod != null) {
-								return;
-							}
-						}
-					}
-				}
+		} else if (this.location instanceof LocationWrapper wrapper) {
+			for (Path locPath : wrapper.getPaths()) {
+				File file = locPath.toFile();
+				IModule mod = ModuleFinder.scanForModule(this, file, null, true, null);
+				if (mod != null)
+					return;
 			}
 		}
 	}
@@ -294,21 +285,8 @@ public boolean hasAnnotationFileFor(String qualifiedTypeName) {
 	public Collection<String> getModuleNames(Collection<String> limitModules) {
 		if (this.jrt != null)
 			return this.jrt.getModuleNames(limitModules);
-		if (this.location.isModuleOrientedLocation()) {
-			Set<String> moduleNames = new HashSet<>();
-			try {
-				for (Set<Location> locs : this.fileManager.listLocationsForModules(this.location)) {
-					for (Location loc : locs) {
-						String moduleName = this.fileManager.inferModuleName(loc);
-						if (moduleName != null)
-							moduleNames.add(moduleName);
-					}
-				}
-				return moduleNames;
-			} catch (IOException e) {
-				// TODO Auto-generated catch block
-				e.printStackTrace();
-			}
+		if (this.module != null) {
+			return Collections.singletonList(String.valueOf(this.module.name()));
 		}
 		return Collections.emptyList();
 	}

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/tool/EclipseCompilerImpl.java

@@ -36,6 +36,7 @@
 import java.util.Locale;
 import java.util.Map;
 import java.util.Optional;
+import java.util.Set;
 import java.util.stream.Stream;
 import javax.annotation.processing.Processor;
 import javax.tools.Diagnostic;
@@ -727,12 +728,31 @@ protected void handleLocations() {
 				fileSystemClasspaths.add(classpath);
 			}
 			if (this.fileManager.hasLocation(StandardLocation.MODULE_SOURCE_PATH)) {
-				classpath = new ClasspathJsr199(this.fileManager, StandardLocation.MODULE_SOURCE_PATH);
-				fileSystemClasspaths.add(classpath);
+				// FIXME: ClasspathJsr199 doesn't really support source files
+				try {
+					Iterable<Set<Location>> locationsForModules = this.fileManager.listLocationsForModules(StandardLocation.MODULE_SOURCE_PATH);
+					for (Set<Location> locs: locationsForModules) {
+						for (Location loc : locs) {
+							classpath = new ClasspathJsr199(this.fileManager, loc);
+							fileSystemClasspaths.add(classpath);
+						}
+					}
+				} catch (IOException e) {
+					this.logger.logException(e);
+				}
 			}
 			if (this.fileManager.hasLocation(StandardLocation.MODULE_PATH)) {
-				classpath = new ClasspathJsr199(this.fileManager, StandardLocation.MODULE_PATH);
-				fileSystemClasspaths.add(classpath);
+				try {
+					Iterable<Set<Location>> locationsForModules = this.fileManager.listLocationsForModules(StandardLocation.MODULE_PATH);
+					for (Set<Location> locs: locationsForModules) {
+						for (Location loc : locs) {
+							classpath = new ClasspathJsr199(this.fileManager, loc);
+							fileSystemClasspaths.add(classpath);
+						}
+					}
+				} catch (IOException e) {
+					this.logger.logException(e);
+				}
 			}
 			classpath = new ClasspathJsr199(this.fileManager, StandardLocation.CLASS_PATH);
 			fileSystemClasspaths.add(classpath);