Class.c

/*
 * Copyright (c) 1994, 2025, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation. Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*-
 * Implementation of class Class
 *
 * former threadruntime.c, Sun Sep 22 12:09:39 1991
 */

#include<string.h>
#include<stdlib.h>

#include"jni.h"
#include"jni_util.h"
#include"jvm.h"
#include"check_classname.h"
#include"java_lang_Class.h"

/* defined in libverify.so/verify.dll (src file common/check_format.c) */
externjbooleanVerifyClassname(char*utf_name, jbooleanarrayAllowed);
externjbooleanVerifyFixClassname(char*utf_name);

#defineOBJ "Ljava/lang/Object;"
#defineCLS "Ljava/lang/Class;"
#defineCPL "Ljdk/internal/reflect/ConstantPool;"
#defineSTR "Ljava/lang/String;"
#defineFLD "Ljava/lang/reflect/Field;"
#defineMHD "Ljava/lang/reflect/Method;"
#defineCTR "Ljava/lang/reflect/Constructor;"
#defineBA "[B"
#defineRC "Ljava/lang/reflect/RecordComponent;"

staticJNINativeMethodmethods[] = {
 {"initClassName", "()"STR, (void*)&JVM_InitClassName},
 {"getSuperclass", "()"CLS, NULL},
 {"getInterfaces0", "()["CLS, (void*)&JVM_GetClassInterfaces},
 {"isHidden", "()Z", (void*)&JVM_IsHiddenClass},
 {"getDeclaredFields0","(Z)["FLD, (void*)&JVM_GetClassDeclaredFields},
 {"getDeclaredMethods0","(Z)["MHD, (void*)&JVM_GetClassDeclaredMethods},
 {"getDeclaredConstructors0","(Z)["CTR, (void*)&JVM_GetClassDeclaredConstructors},
 {"getDeclaredClasses0", "()["CLS, (void*)&JVM_GetDeclaredClasses},
 {"getDeclaringClass0", "()"CLS, (void*)&JVM_GetDeclaringClass},
 {"getSimpleBinaryName0", "()"STR, (void*)&JVM_GetSimpleBinaryName},
 {"getGenericSignature0", "()"STR, (void*)&JVM_GetClassSignature},
 {"getRawAnnotations", "()"BA, (void*)&JVM_GetClassAnnotations},
 {"getConstantPool", "()"CPL, (void*)&JVM_GetClassConstantPool},
 {"desiredAssertionStatus0","("CLS")Z", (void*)&JVM_DesiredAssertionStatus},
 {"getEnclosingMethod0", "()["OBJ, (void*)&JVM_GetEnclosingMethodInfo},
 {"getRawTypeAnnotations", "()"BA, (void*)&JVM_GetClassTypeAnnotations},
 {"getNestHost0", "()"CLS, (void*)&JVM_GetNestHost},
 {"getNestMembers0", "()["CLS, (void*)&JVM_GetNestMembers},
 {"getRecordComponents0", "()["RC, (void*)&JVM_GetRecordComponents},
 {"isRecord0", "()Z", (void*)&JVM_IsRecord},
 {"getPermittedSubclasses0", "()["CLS, (void*)&JVM_GetPermittedSubclasses},
 {"getClassFileVersion0", "()I", (void*)&JVM_GetClassFileVersion},
 {"getClassAccessFlagsRaw0", "()I", (void*)&JVM_GetClassAccessFlags},
};

#undef OBJ
#undef CLS
#undef STR
#undef FLD
#undef MHD
#undef CTR
#undef PD

JNIEXPORTvoidJNICALL
Java_java_lang_Class_registerNatives(JNIEnv*env, jclasscls)
{
methods[1].fnPtr= (void*)(*env)->GetSuperclass;
 (*env)->RegisterNatives(env, cls, methods,
sizeof(methods)/sizeof(JNINativeMethod));
}

JNIEXPORTjclassJNICALL
Java_java_lang_Class_forName0(JNIEnv*env, jclassthis, jstringclassname,
jbooleaninitialize, jobjectloader, jclasscaller)
{
char*clname;
jclasscls=0;
charbuf[128];
jsizelen;
jsizeunicode_len;

if (classname==NULL) {
JNU_ThrowNullPointerException(env, 0);
return0;
 }

len= (*env)->GetStringUTFLength(env, classname);
unicode_len= (*env)->GetStringLength(env, classname);
if (len >= (jsize)sizeof(buf)) {
clname=malloc(len+1);
if (clname==NULL) {
JNU_ThrowOutOfMemoryError(env, NULL);
returnNULL;
 }
 } else {
clname=buf;
 }
 (*env)->GetStringUTFRegion(env, classname, 0, unicode_len, clname);

if (verifyFixClassname(clname) ==JNI_TRUE) {
/* slashes present in clname, use name b4 translation for exception */
 (*env)->GetStringUTFRegion(env, classname, 0, unicode_len, clname);
JNU_ThrowClassNotFoundException(env, clname);
 goto done;
 }

if (!verifyClassname(clname, JNI_TRUE)) { /* expects slashed name */
JNU_ThrowClassNotFoundException(env, clname);
 goto done;
 }

cls=JVM_FindClassFromCaller(env, clname, initialize, loader, caller);

done:
if (clname!=buf) {
free(clname);
 }
returncls;
}

JNIEXPORTjbooleanJNICALL
Java_java_lang_Class_isInstance(JNIEnv*env, jobjectcls, jobjectobj)
{
if (obj==NULL) {
returnJNI_FALSE;
 }
return (*env)->IsInstanceOf(env, obj, (jclass)cls);
}

JNIEXPORTjbooleanJNICALL
Java_java_lang_Class_isAssignableFrom(JNIEnv*env, jobjectcls, jobjectcls2)
{
if (cls2==NULL) {
JNU_ThrowNullPointerException(env, 0);
returnJNI_FALSE;
 }
return (*env)->IsAssignableFrom(env, cls2, cls);
}

JNIEXPORTjclassJNICALL
Java_java_lang_Class_getPrimitiveClass(JNIEnv*env,
jclasscls,
jstringname)
{
constchar*utfName;
jclassresult;

if (name==NULL) {
JNU_ThrowNullPointerException(env, 0);
returnNULL;
 }

utfName= (*env)->GetStringUTFChars(env, name, 0);
if (utfName==0)
returnNULL;

result=JVM_FindPrimitiveClass(env, utfName);

 (*env)->ReleaseStringUTFChars(env, name, utfName);

returnresult;
}