6864003: Modify JVM_FindClassFromBootLoader to return null if class not found

Summary: JVM_FindClassFromBootLoader returns null if class not found
Reviewed-by: acorn, alanb, dholmes

src/share/vm/prims/jvm.cpp

@@ -638,32 +638,10 @@ JVM_ENTRY(void, JVM_ResolveClass(JNIEnv* env, jclass cls))
   if (PrintJVMWarnings) warning("JVM_ResolveClass not implemented");
 JVM_END
 
-// Common implementation for JVM_FindClassFromBootLoader and
-// JVM_FindClassFromLoader
-static jclass jvm_find_class_from_class_loader(JNIEnv* env, const char* name,
-                                  jboolean init, jobject loader,
-                                  jboolean throwError, TRAPS) {
-  // Java libraries should ensure that name is never null...
-  if (name == NULL || (int)strlen(name) > symbolOopDesc::max_length()) {
-    // It's impossible to create this class;  the name cannot fit
-    // into the constant pool.
-    if (throwError) {
-      THROW_MSG_0(vmSymbols::java_lang_NoClassDefFoundError(), name);
-    } else {
-      THROW_MSG_0(vmSymbols::java_lang_ClassNotFoundException(), name);
-    }
-  }
-  symbolHandle h_name = oopFactory::new_symbol_handle(name, CHECK_NULL);
-  Handle h_loader(THREAD, JNIHandles::resolve(loader));
-  jclass result = find_class_from_class_loader(env, h_name, init, h_loader,
-                                               Handle(), throwError, THREAD);
-
-  if (TraceClassResolution && result != NULL) {
-    trace_class_resolution(java_lang_Class::as_klassOop(JNIHandles::resolve_non_null(result)));
-  }
-  return result;
-}
 
+// Returns a class loaded by the bootstrap class loader; or null
+// if not found.  ClassNotFoundException is not thrown.
+//
 // Rationale behind JVM_FindClassFromBootLoader
 // a> JVM_FindClassFromClassLoader was never exported in the export tables.
 // b> because of (a) java.dll has a direct dependecy on the  unexported
@@ -681,12 +659,26 @@ static jclass jvm_find_class_from_class_loader(JNIEnv* env, const char* name,
 // to the JDK, and is not intended to be a public API.
 
 JVM_ENTRY(jclass, JVM_FindClassFromBootLoader(JNIEnv* env,
-                                              const char* name,
-                                              jboolean throwError))
-  JVMWrapper3("JVM_FindClassFromBootLoader %s throw %s", name,
-              throwError ? "error" : "exception");
-  return jvm_find_class_from_class_loader(env, name, JNI_FALSE,
-                                          (jobject)NULL, throwError, THREAD);
+                                              const char* name))
+  JVMWrapper2("JVM_FindClassFromBootLoader %s", name);
+
+  // Java libraries should ensure that name is never null...
+  if (name == NULL || (int)strlen(name) > symbolOopDesc::max_length()) {
+    // It's impossible to create this class;  the name cannot fit
+    // into the constant pool.
+    return NULL;
+  }
+
+  symbolHandle h_name = oopFactory::new_symbol_handle(name, CHECK_NULL);
+  klassOop k = SystemDictionary::resolve_or_null(h_name, CHECK_NULL);
+  if (k == NULL) {
+    return NULL;
+  }
+
+  if (TraceClassResolution) {
+    trace_class_resolution(k);
+  }
+  return (jclass) JNIHandles::make_local(env, Klass::cast(k)->java_mirror());
 JVM_END
 
 JVM_ENTRY(jclass, JVM_FindClassFromClassLoader(JNIEnv* env, const char* name,
@@ -694,8 +686,25 @@ JVM_ENTRY(jclass, JVM_FindClassFromClassLoader(JNIEnv* env, const char* name,
                                                jboolean throwError))
   JVMWrapper3("JVM_FindClassFromClassLoader %s throw %s", name,
                throwError ? "error" : "exception");
-  return jvm_find_class_from_class_loader(env, name, init, loader,
-                                          throwError, THREAD);
+  // Java libraries should ensure that name is never null...
+  if (name == NULL || (int)strlen(name) > symbolOopDesc::max_length()) {
+    // It's impossible to create this class;  the name cannot fit
+    // into the constant pool.
+    if (throwError) {
+      THROW_MSG_0(vmSymbols::java_lang_NoClassDefFoundError(), name);
+    } else {
+      THROW_MSG_0(vmSymbols::java_lang_ClassNotFoundException(), name);
+    }
+  }
+  symbolHandle h_name = oopFactory::new_symbol_handle(name, CHECK_NULL);
+  Handle h_loader(THREAD, JNIHandles::resolve(loader));
+  jclass result = find_class_from_class_loader(env, h_name, init, h_loader,
+                                               Handle(), throwError, THREAD);
+
+  if (TraceClassResolution && result != NULL) {
+    trace_class_resolution(java_lang_Class::as_klassOop(JNIHandles::resolve_non_null(result)));
+  }
+  return result;
 JVM_END
 
 
@@ -3919,6 +3928,7 @@ jclass find_class_from_class_loader(JNIEnv* env, symbolHandle name, jboolean ini
   //   The Java level wrapper will perform the necessary security check allowing
   //   us to pass the NULL as the initiating class loader.
   klassOop klass = SystemDictionary::resolve_or_fail(name, loader, protection_domain, throwError != 0, CHECK_NULL);
+
   KlassHandle klass_handle(THREAD, klass);
   // Check if we should initialize the class
   if (init && klass_handle->oop_is_instance()) {

src/share/vm/prims/jvm.h

@@ -390,15 +390,10 @@ JVM_FindClassFromClassLoader(JNIEnv *env, const char *name, jboolean init,
                              jobject loader, jboolean throwError);
 
 /*
- * Find a class from a boot class loader. Throw ClassNotFoundException
- * or NoClassDefFoundError depending on the value of the last
- * argument. This is the same as FindClassFromClassLoader but provided
- * as a convenience method exported correctly on all platforms for
- * JSR 277 launcher class loading.
+ * Find a class from a boot class loader. Returns NULL if class not found.
  */
 JNIEXPORT jclass JNICALL
-JVM_FindClassFromBootLoader(JNIEnv *env, const char *name,
-                            jboolean throwError);
+JVM_FindClassFromBootLoader(JNIEnv *env, const char *name);
 
 /*
  * Find a class from a given class.