8323815: Source launcher should find classes with $ in names

Reviewed-by: jlahoda, sundar

src/jdk.compiler/share/classes/com/sun/tools/javac/launcher/MemoryContext.java

@@ -170,11 +170,22 @@ public void started(TaskEvent event) {
      *         if no source file was found for the given name
      */
     byte[] compileJavaFileByName(String name) {
+        // Initially, determine existing directory from class name.
+        // [pack$age . ] na$me [ $ enclo$ed [$ dee$per] ]
+        var lastDot = name.lastIndexOf(".");
+        var packageName = lastDot == -1 ? "" : name.substring(0, lastDot);
+        var packagePath = descriptor.sourceRootPath().resolve(packageName.replace('.', '/'));
+        // Trivial case: no matching directory exists
+        if (!Files.isDirectory(packagePath)) return null;
+
         // Determine source file from class name.
-        var firstDollarSign = name.indexOf('$'); // [package . ] name [ $ enclosed [$ deeper] ]
-        var packageAndClassName = firstDollarSign == -1 ? name : name.substring(0, firstDollarSign);
-        var path = packageAndClassName.replace('.', '/') + ".java";
-        var file = descriptor.sourceRootPath().resolve(path);
+        var candidate = name.substring(lastDot + 1, name.length()); // "na$me$enclo$ed$dee$per"
+        // For each `$` in the name try to find the first matching compilation unit.
+        while (candidate.contains("$")) {
+            if (Files.exists(packagePath.resolve(candidate + ".java"))) break;
+            candidate = candidate.substring(0, candidate.lastIndexOf("$"));
+        }
+        var file = packagePath.resolve(candidate + ".java");
 
         // Trivial case: no matching source file exists
         if (!Files.exists(file)) return null;

test/langtools/tools/javac/launcher/MultiFileSourceLauncherTests.java

@@ -75,7 +75,9 @@ void testLoadingOfEnclosedTypes(@TempDir Path base) throws Exception {
                     public class Hello {
                       public static void main(String... args) throws Exception {
                         System.out.println(Class.forName("World$Core"));
-                        System.out.println(Class.forName("p.q.Unit$First$Second"));
+                        System.out.println(Class.forName("p.q.Unit$Fir$t"));
+                        System.out.println(Class.forName("p.q.Unit$123$Fir$t$$econd"));
+                        System.out.println(Class.forName("$.$.$"));
                       }
                     }
                     """);
@@ -90,18 +92,35 @@ record Core() {}
                     """
                     package p.q;
                     record Unit() {
-                      record First() {
-                        record Second() {}
+                      record Fir$t() {
+                        record $econd() {}
                       }
                     }
                     """);
+        Files.writeString(pq.resolve("Unit$123.java"),
+                    """
+                    package p.q;
+                    record Unit$123() {
+                      record Fir$t() {
+                        record $econd() {}
+                      }
+                    }
+                    """);
+        var $$ = Files.createDirectories(base.resolve("$/$"));
+        Files.writeString($$.resolve("$.java"),
+                    """
+                    package $.$;
+                    record $($ $) {}
+                    """);
 
         var run = Run.of(hello);
         assertAll("Run -> " + run,
                 () -> assertLinesMatch(
                         """
                         class World$Core
-                        class p.q.Unit$First$Second
+                        class p.q.Unit$Fir$t
+                        class p.q.Unit$123$Fir$t$$econd
+                        class $.$.$
                         """.lines(),
                         run.stdOut().lines()),
                 () -> assertTrue(run.stdErr().isEmpty()),