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Diffstat (limited to 'libjava/java/lang/natClassLoader.cc')
| -rw-r--r-- | libjava/java/lang/natClassLoader.cc | 734 |
1 files changed, 734 insertions, 0 deletions
diff --git a/libjava/java/lang/natClassLoader.cc b/libjava/java/lang/natClassLoader.cc new file mode 100644 index 000000000..237e038d1 --- /dev/null +++ b/libjava/java/lang/natClassLoader.cc @@ -0,0 +1,734 @@ +// natClassLoader.cc - Implementation of java.lang.ClassLoader native methods. + +/* Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2008 Free Software Foundation + + This file is part of libgcj. + +This software is copyrighted work licensed under the terms of the +Libgcj License. Please consult the file "LIBGCJ_LICENSE" for +details. */ + +/* Author: Kresten Krab Thorup <krab@gnu.org> */ + +#include <config.h> + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> + +#include <gcj/cni.h> +#include <jvm.h> +#include <execution.h> + +#include <java-threads.h> +#include <java-interp.h> + +#include <java/lang/Character.h> +#include <java/lang/Thread.h> +#include <java/lang/ClassLoader.h> +#include <java/lang/InternalError.h> +#include <java/lang/IllegalAccessError.h> +#include <java/lang/LinkageError.h> +#include <java/lang/NoClassDefFoundError.h> +#include <java/lang/ClassNotFoundException.h> +#include <java/lang/ClassCircularityError.h> +#include <java/lang/IncompatibleClassChangeError.h> +#include <java/lang/ClassFormatError.h> +#include <java/lang/VirtualMachineError.h> +#include <java/lang/VMClassLoader.h> +#include <java/lang/reflect/Modifier.h> +#include <java/lang/Runtime.h> +#include <java/lang/StringBuffer.h> +#include <java/io/Serializable.h> +#include <java/lang/Cloneable.h> +#include <java/lang/ref/WeakReference.h> +#include <java/util/HashMap.h> +#include <gnu/gcj/runtime/BootClassLoader.h> +#include <gnu/gcj/runtime/SystemClassLoader.h> + +// Size of local hash table. +#define HASH_LEN 1013 + +// Hash function for Utf8Consts. +#define HASH_UTF(Utf) ((Utf)->hash16() % HASH_LEN) + +// This records classes which will be registered with the system class +// loader when it is initialized. +static jclass system_class_list; + +// This is used as the value of system_class_list after we have +// initialized the system class loader; it lets us know that we should +// no longer pay attention to the system abi flag. +#define SYSTEM_LOADER_INITIALIZED ((jclass) -1) + +static jclass loaded_classes[HASH_LEN]; + +// This is the root of a linked list of classes +static jclass stack_head; + +// While bootstrapping we keep a list of classes we found, so that we +// can register their packages. There aren't many of these so we +// just keep a small buffer here and abort if we overflow. +#define BOOTSTRAP_CLASS_LIST_SIZE 20 +static jclass bootstrap_class_list[BOOTSTRAP_CLASS_LIST_SIZE]; +static int bootstrap_index; + + + + +jclass +java::lang::ClassLoader::loadClassFromSig(jstring name) +{ + int len = _Jv_GetStringUTFLength (name); + char sig[len + 1]; + _Jv_GetStringUTFRegion (name, 0, name->length(), sig); + jclass result = _Jv_FindClassFromSignature(sig, this); + if (result == NULL) + throw new ClassNotFoundException(name); + return result; +} + + + +// This tries to find a class in our built-in cache. This cache is +// used only for classes which are linked in to the executable or +// loaded via dlopen(). +jclass +_Jv_FindClassInCache (_Jv_Utf8Const *name) +{ + JvSynchronize sync (&java::lang::Class::class$); + jint hash = HASH_UTF (name); + + jclass klass; + for (klass = loaded_classes[hash]; klass; klass = klass->next_or_version) + { + if (_Jv_equalUtf8Consts (name, klass->name)) + break; + } + + return klass; +} + +void +_Jv_UnregisterClass (jclass the_class) +{ + // This can happen if the class could not be defined properly. + if (! the_class->name) + return; + + JvSynchronize sync (&java::lang::Class::class$); + jint hash = HASH_UTF(the_class->name); + + jclass *klass = &(loaded_classes[hash]); + for ( ; *klass; klass = &((*klass)->next_or_version)) + { + if (*klass == the_class) + { + *klass = (*klass)->next_or_version; + break; + } + } +} + +// Register an initiating class loader for a given class. +void +_Jv_RegisterInitiatingLoader (jclass klass, java::lang::ClassLoader *loader) +{ + if (! loader) + loader = java::lang::VMClassLoader::bootLoader; + if (! loader) + { + // Very early in the bootstrap process, the Bootstrap classloader may + // not exist yet. + // FIXME: We could maintain a list of these and come back and register + // them later. + return; + } + + JvSynchronize sync (loader->loadingConstraints); + + using namespace java::lang::ref; + + jstring name = klass->getName(); + WeakReference *ref = (WeakReference *) loader->loadingConstraints->get (name); + if (ref) + { + jclass constraint = (jclass) ref->get(); + if (constraint && constraint != klass) + throw new java::lang::LinkageError(JvNewStringLatin1("loading constraint violated")); + } + loader->loadingConstraints->put(name, new WeakReference(klass)); + loader->loadedClasses->put(name, klass); +} + +// If we found an error while defining an interpreted class, we must +// go back and unregister it. +void +_Jv_UnregisterInitiatingLoader (jclass klass, java::lang::ClassLoader *loader) +{ + if (! loader) + loader = java::lang::VMClassLoader::bootLoader; + loader->loadedClasses->remove(klass->name->toString()); +} + +// Check a loading constraint. In particular check that, if there is +// a constraint for the name of KLASS in LOADER, that it maps to +// KLASS. If there is no such constraint, make a new one. If the +// constraint is violated, throw an exception. Do nothing for +// primitive types. +void +_Jv_CheckOrCreateLoadingConstraint (jclass klass, + java::lang::ClassLoader *loader) +{ + // Strip arrays. + while (klass->isArray()) + klass = klass->getComponentType(); + // Ignore primitive types. + if (klass->isPrimitive()) + return; + + if (! loader) + loader = java::lang::VMClassLoader::bootLoader; + jstring name = klass->getName(); + + JvSynchronize sync (loader->loadingConstraints); + + using namespace java::lang::ref; + + WeakReference *ref = (WeakReference *) loader->loadingConstraints->get (name); + if (ref) + { + jclass constraint = (jclass) ref->get(); + if (constraint) + { + if (klass != constraint) + throw new java::lang::LinkageError(JvNewStringLatin1("loading constraint violated")); + // Otherwise, all is ok. + return; + } + } + // No constraint (or old constraint GC'd). Make a new one. + loader->loadingConstraints->put(name, new WeakReference(klass)); +} + + +// Class registration. +// +// There are two kinds of functions that register classes. +// +// Type 1: +// +// These take the address of a class that is in an object file. +// Because these classes are not allocated on the heap, It is also +// necessary to register the address of the object for garbage +// collection. This is used with the "old" C++ ABI and with +// -findirect-dispatch -fno-indirect-classes. +// +// Type 2: +// +// These take an initializer struct, create the class, and return the +// address of the newly created class to their caller. These are used +// with -findirect-dispatch. +// +// _Jv_RegisterClasses() and _Jv_RegisterClasses_Counted() are +// functions of Type 1, and _Jv_NewClassFromInitializer() and +// _Jv_RegisterNewClasses() are of Type 2. + + +// Check that the file we're trying to load has been compiled with a +// compatible version of gcj. In previous versions of libgcj we +// silently failed to register classes of an incompatible ABI version, +// but this was totally bogus. +void +_Jv_CheckABIVersion (unsigned long value) +{ + // We are compatible with GCJ 4.0.0 BC-ABI classes. This release used a + // different format for the version ID string. + if (value == OLD_GCJ_40_BC_ABI_VERSION) + return; + + // The 20 low-end bits are used for the version number. + unsigned long version = value & 0xfffff; + + if (value & FLAG_BINARYCOMPAT_ABI) + { + int abi_rev = version % 100; + int abi_ver = version - abi_rev; + // We are compatible with abi_rev 0 and 1. + if (abi_ver == GCJ_40_BC_ABI_VERSION && abi_rev <= 1) + return; + } + else + { + // C++ ABI + if (version == GCJ_CXX_ABI_VERSION) + return; + + // If we've loaded a library that uses the C++ ABI, and this + // library is an incompatible version, then we're dead. There's + // no point throwing an exception: that will crash. + JvFail ("gcj linkage error.\n" + "Incorrect library ABI version detected. Aborting.\n"); + } + + throw new ::java::lang::ClassFormatError + (JvNewStringLatin1 ("Library compiled with later ABI version than" + " this version of libgcj supports")); +} + +// This function is called many times during startup, before main() is +// run. At that point in time we know for certain we are running +// single-threaded, so we don't need to lock when adding classes to the +// class chain. At all other times, the caller should synchronize on +// Class::class$. +void +_Jv_RegisterClasses (const jclass *classes) +{ + _Jv_RegisterLibForGc (classes); + + for (; *classes; ++classes) + { + jclass klass = *classes; + + _Jv_CheckABIVersion ((unsigned long) klass->next_or_version); + (*_Jv_RegisterClassHook) (klass); + } +} + +// This is a version of _Jv_RegisterClasses that takes a count. +void +_Jv_RegisterClasses_Counted (const jclass * classes, size_t count) +{ + size_t i; + + _Jv_RegisterLibForGc (classes); + + for (i = 0; i < count; i++) + { + jclass klass = classes[i]; + + _Jv_CheckABIVersion ((unsigned long) klass->next_or_version); + (*_Jv_RegisterClassHook) (klass); + } +} + +// Create a class on the heap from an initializer struct. +inline jclass +_Jv_NewClassFromInitializer (const char *class_initializer) +{ + const unsigned long version + = ((unsigned long) + ((::java::lang::Class *)class_initializer)->next_or_version); + _Jv_CheckABIVersion (version); + + /* We create an instance of java::lang::Class and copy all of its + fields except the first word (the vtable pointer) from + CLASS_INITIALIZER. This first word is pre-initialized by + _Jv_AllocObj, and we don't want to overwrite it. */ + + jclass new_class + = (jclass)_Jv_AllocObj (sizeof (::java::lang::Class), + &::java::lang::Class::class$); + const char *src = class_initializer + sizeof (void*); + char *dst = (char*)new_class + sizeof (void*); + size_t len = (::java::lang::Class::initializerSize (version) + - sizeof (void*)); + memcpy (dst, src, len); + + new_class->engine = &_Jv_soleIndirectCompiledEngine; + + /* FIXME: Way back before the dawn of time, we overloaded the + SYNTHETIC class access modifier to mean INTERPRETED. This was a + Bad Thing, but it didn't matter then because classes were never + marked synthetic. However, it is possible to redeem the + situation: _Jv_NewClassFromInitializer is only called from + compiled classes, so we clear the INTERPRETED flag. This is a + kludge! */ + new_class->accflags &= ~java::lang::reflect::Modifier::INTERPRETED; + + (*_Jv_RegisterClassHook) (new_class); + + return new_class; +} + +// Called by compiler-generated code at DSO initialization. CLASSES +// is an array of pairs: the first item of each pair is a pointer to +// the initialized data that is a class initializer in a DSO, and the +// second is a pointer to a class reference. +// _Jv_NewClassFromInitializer() creates the new class (on the Java +// heap) and we write the address of the new class into the address +// pointed to by the second word. +void +_Jv_RegisterNewClasses (char **classes) +{ + _Jv_InitGC (); + + const char *initializer; + + while ((initializer = *classes++)) + { + jclass *class_ptr = (jclass *)*classes++; + *class_ptr = _Jv_NewClassFromInitializer (initializer); + } +} + +void +_Jv_RegisterClassHookDefault (jclass klass) +{ + // This is bogus, but there doesn't seem to be a better place to do + // it. + if (! klass->engine) + klass->engine = &_Jv_soleCompiledEngine; + + /* FIXME: Way back before the dawn of time, we overloaded the + SYNTHETIC class access modifier to mean INTERPRETED. This was a + Bad Thing, but it didn't matter then because classes were never + marked synthetic. However, it is possible to redeem the + situation: _Jv_RegisterClassHookDefault is only called from + compiled classes, so we clear the INTERPRETED flag. This is a + kludge! */ + klass->accflags &= ~java::lang::reflect::Modifier::INTERPRETED; + + if (system_class_list != SYSTEM_LOADER_INITIALIZED) + { + unsigned long abi = (unsigned long) klass->next_or_version; + if (! _Jv_ClassForBootstrapLoader (abi)) + { + klass->next_or_version = system_class_list; + system_class_list = klass; + return; + } + } + + jint hash = HASH_UTF (klass->name); + + // If the class is already registered, don't re-register it. + for (jclass check_class = loaded_classes[hash]; + check_class != NULL; + check_class = check_class->next_or_version) + { + if (check_class == klass) + { + // If you get this, it means you have the same class in two + // different libraries. +#define TEXT "Duplicate class registration: " + // We size-limit MESSAGE so that you can't trash the stack. + char message[200]; + strcpy (message, TEXT); + strncpy (message + sizeof (TEXT) - 1, klass->name->chars(), + sizeof (message) - sizeof (TEXT)); + message[sizeof (message) - 1] = '\0'; + if (! gcj::runtimeInitialized) + JvFail (message); + else + { + java::lang::String *str = JvNewStringLatin1 (message); + throw new java::lang::VirtualMachineError (str); + } + } + } + + klass->next_or_version = loaded_classes[hash]; + loaded_classes[hash] = klass; +} + +// A pointer to a function that actually registers a class. +// Normally _Jv_RegisterClassHookDefault, but could be some other function +// that registers the class in e.g. a ClassLoader-local table. +// Should synchronize on Class:class$ while setting/restore this variable. + +void (*_Jv_RegisterClassHook) (jclass cl) = _Jv_RegisterClassHookDefault; + +void +_Jv_RegisterClass (jclass klass) +{ + jclass classes[2]; + classes[0] = klass; + classes[1] = NULL; + _Jv_RegisterClasses (classes); +} + +// This is used during initialization to register all compiled-in +// classes that are not part of the core with the system class loader. +void +_Jv_CopyClassesToSystemLoader (gnu::gcj::runtime::SystemClassLoader *loader) +{ + for (jclass klass = system_class_list; + klass; + klass = klass->next_or_version) + { + klass->loader = loader; + loader->addClass(klass); + } + system_class_list = SYSTEM_LOADER_INITIALIZED; +} + +// An internal variant of _Jv_FindClass which simply swallows a +// NoClassDefFoundError or a ClassNotFoundException. This gives the +// caller a chance to evaluate the situation and behave accordingly. +jclass +_Jv_FindClassNoException (_Jv_Utf8Const *name, java::lang::ClassLoader *loader) +{ + jclass klass; + + try + { + klass = _Jv_FindClass(name, loader); + } + catch ( java::lang::NoClassDefFoundError *ncdfe ) + { + return NULL; + } + catch ( java::lang::ClassNotFoundException *cnfe ) + { + return NULL; + } + + return klass; +} + +jclass +_Jv_FindClass (_Jv_Utf8Const *name, java::lang::ClassLoader *loader) +{ + // See if the class was already loaded by this loader. This handles + // initiating loader checks, as we register classes with their + // initiating loaders. + + java::lang::ClassLoader *boot = java::lang::VMClassLoader::bootLoader; + java::lang::ClassLoader *real = loader; + if (! real) + real = boot; + jstring sname = name->toString(); + // We might still be bootstrapping the VM, in which case there + // won't be a bootstrap class loader yet. + jclass klass = real ? real->findLoadedClass (sname) : NULL; + + if (! klass) + { + if (loader) + { + // Load using a user-defined loader, jvmspec 5.3.2. + // Note that we explicitly must call the single-argument form. + klass = loader->loadClass(sname); + + // If "loader" delegated the loadClass operation to another + // loader, explicitly register that it is also an initiating + // loader of the given class. + java::lang::ClassLoader *delegate = (loader == boot + ? NULL + : loader); + if (klass && klass->getClassLoaderInternal () != delegate) + _Jv_RegisterInitiatingLoader (klass, loader); + } + else if (boot) + { + // Load using the bootstrap loader jvmspec 5.3.1. + klass = java::lang::VMClassLoader::loadClass (sname, false); + + // Register that we're an initiating loader. + if (klass) + _Jv_RegisterInitiatingLoader (klass, 0); + } + else + { + // Not even a bootstrap loader, try the built-in cache. + klass = _Jv_FindClassInCache (name); + + if (klass) + { + bool found = false; + for (int i = 0; i < bootstrap_index; ++i) + { + if (bootstrap_class_list[i] == klass) + { + found = true; + break; + } + } + if (! found) + { + if (bootstrap_index == BOOTSTRAP_CLASS_LIST_SIZE) + abort (); + bootstrap_class_list[bootstrap_index++] = klass; + } + } + } + } + + return klass; +} + +void +_Jv_RegisterBootstrapPackages () +{ + for (int i = 0; i < bootstrap_index; ++i) + java::lang::VMClassLoader::definePackageForNative(bootstrap_class_list[i]->getName()); +} + +jclass +_Jv_NewClass (_Jv_Utf8Const *name, jclass superclass, + java::lang::ClassLoader *loader) +{ + jclass ret = (jclass) _Jv_AllocObject (&java::lang::Class::class$); + ret->name = name; + ret->superclass = superclass; + ret->loader = loader; + + _Jv_RegisterInitiatingLoader (ret, loader); + + return ret; +} + +static _Jv_IDispatchTable *array_idt = NULL; +static jshort array_depth = 0; +static jclass *array_ancestors = NULL; + +static jclass interfaces[] = +{ + &java::lang::Cloneable::class$, + &java::io::Serializable::class$ +}; + +// Create a class representing an array of ELEMENT and store a pointer to it +// in element->arrayclass. LOADER is the ClassLoader which _initiated_ the +// instantiation of this array. ARRAY_VTABLE is the vtable to use for the new +// array class. This parameter is optional. +void +_Jv_NewArrayClass (jclass element, java::lang::ClassLoader *loader, + _Jv_VTable *array_vtable) +{ + JvSynchronize sync (element); + + _Jv_Utf8Const *array_name; + int len; + + if (element->arrayclass) + return; + + if (element->isPrimitive()) + { + if (element == JvPrimClass (void)) + throw new java::lang::ClassNotFoundException (); + len = 3; + } + else + len = element->name->len() + 5; + + { + char signature[len]; + int index = 0; + signature[index++] = '['; + // Compute name of array class. + if (element->isPrimitive()) + { + signature[index++] = (char) element->method_count; + } + else + { + size_t length = element->name->len(); + const char *const name = element->name->chars(); + if (name[0] != '[') + signature[index++] = 'L'; + memcpy (&signature[index], name, length); + index += length; + if (name[0] != '[') + signature[index++] = ';'; + } + array_name = _Jv_makeUtf8Const (signature, index); + } + + // Create new array class. + jclass array_class = _Jv_NewClass (array_name, &java::lang::Object::class$, + element->loader); + + // Note that `vtable_method_count' doesn't include the initial + // gc_descr slot. + int dm_count = java::lang::Object::class$.vtable_method_count; + + // Create a new vtable by copying Object's vtable. + _Jv_VTable *vtable; + if (array_vtable) + vtable = array_vtable; + else + vtable = _Jv_VTable::new_vtable (dm_count); + vtable->clas = array_class; + vtable->gc_descr = java::lang::Object::class$.vtable->gc_descr; + for (int i = 0; i < dm_count; ++i) + vtable->set_method (i, java::lang::Object::class$.vtable->get_method (i)); + + array_class->vtable = vtable; + array_class->vtable_method_count + = java::lang::Object::class$.vtable_method_count; + + // Stash the pointer to the element type. + array_class->element_type = element; + + // Register our interfaces. + array_class->interfaces = interfaces; + array_class->interface_count = sizeof interfaces / sizeof interfaces[0]; + + // Since all array classes have the same interface dispatch table, we can + // cache one and reuse it. It is not necessary to synchronize this. + if (!array_idt) + { + _Jv_Linker::wait_for_state(array_class, JV_STATE_PREPARED); + array_idt = array_class->idt; + array_depth = array_class->depth; + array_ancestors = array_class->ancestors; + } + else + { + array_class->idt = array_idt; + array_class->depth = array_depth; + array_class->ancestors = array_ancestors; + } + + using namespace java::lang::reflect; + { + // Array classes are "abstract final" and inherit accessibility + // from element type, per vmspec 5.3.3.2 + _Jv_ushort accflags = (Modifier::FINAL | Modifier::ABSTRACT + | (element->accflags + & (Modifier::PUBLIC | Modifier::PROTECTED + | Modifier::PRIVATE))); + array_class->accflags = accflags; + } + + // An array class has no visible instance fields. "length" is invisible to + // reflection. + + // Say this class is initialized and ready to go! + array_class->state = JV_STATE_DONE; + + // vmspec, section 5.3.3 describes this + if (element->loader != loader) + _Jv_RegisterInitiatingLoader (array_class, loader); + + element->arrayclass = array_class; +} + +// These two functions form a stack of classes. When a class is loaded +// it is pushed onto the stack by the class loader; this is so that +// StackTrace can quickly determine which classes have been loaded. + +jclass +_Jv_PopClass (void) +{ + JvSynchronize sync (&java::lang::Class::class$); + if (stack_head) + { + jclass tmp = stack_head; + stack_head = tmp->chain; + return tmp; + } + return NULL; +} + +void +_Jv_PushClass (jclass k) +{ + JvSynchronize sync (&java::lang::Class::class$); + jclass tmp = stack_head; + stack_head = k; + k->chain = tmp; +} |