1 // defineclass.cc - defining a class from .class format.
3 /* Copyright (C) 1999, 2000, 2001, 2002, 2003 Free Software Foundation
5 This file is part of libgcj.
7 This software is copyrighted work licensed under the terms of the
8 Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
12 Author: Kresten Krab Thorup <krab@gnu.org>
14 Written using the online versions of Java Language Specification (1st
15 ed.) and The Java Virtual Machine Specification (2nd ed.).
17 Future work may include reading (and handling) attributes which are
18 currently being ignored ("InnerClasses", "LineNumber", etc...).
23 #include <java-interp.h>
26 #include <java-cpool.h>
29 #include <java/lang/Class.h>
30 #include <java/lang/Float.h>
31 #include <java/lang/Double.h>
32 #include <java/lang/Character.h>
33 #include <java/lang/LinkageError.h>
34 #include <java/lang/InternalError.h>
35 #include <java/lang/ClassFormatError.h>
36 #include <java/lang/NoClassDefFoundError.h>
37 #include <java/lang/ClassCircularityError.h>
38 #include <java/lang/IncompatibleClassChangeError.h>
39 #include <java/lang/reflect/Modifier.h>
45 // these go in some separate functions, to avoid having _Jv_InitClass
46 // inserted all over the place.
47 static void throw_internal_error (char *msg)
48 __attribute__ ((__noreturn__));
49 static void throw_no_class_def_found_error (jstring msg)
50 __attribute__ ((__noreturn__));
51 static void throw_no_class_def_found_error (char *msg)
52 __attribute__ ((__noreturn__));
53 static void throw_class_format_error (jstring msg)
54 __attribute__ ((__noreturn__));
55 static void throw_incompatible_class_change_error (jstring msg)
56 __attribute__ ((__noreturn__));
57 static void throw_class_circularity_error (jstring msg)
58 __attribute__ ((__noreturn__));
61 * We define class reading using a class. It is practical, since then
62 * the entire class-reader can be a friend of class Class (it needs to
63 * write all it's different structures); but also because this makes it
64 * easy to make class definition reentrant, and thus two threads can be
65 * defining classes at the same time. This class (_Jv_ClassReader) is
66 * never exposed outside this file, so we don't have to worry about
67 * public or private members here.
70 struct _Jv_ClassReader {
72 // do verification? Currently, there is no option to disable this.
73 // This flag just controls the verificaiton done by the class loader;
74 // i.e., checking the integrity of the constant pool; and it is
75 // allways on. You always want this as far as I can see, but it also
76 // controls weither identifiers and type descriptors/signatures are
77 // verified as legal. This could be somewhat more expensive since it
78 // will call Character.isJavaIdentifier{Start,Part} for each character
79 // in any identifier (field name or method name) it comes by. Thus,
80 // it might be useful to turn off this verification for classes that
81 // come from a trusted source. However, for GCJ, trusted classes are
82 // most likely to be linked in.
90 // current input position
93 // the constant pool data
96 unsigned int *offsets;
98 // the class to define (see java-interp.h)
101 // the classes associated interpreter data.
102 _Jv_InterpClass *def_interp;
104 /* check that the given number of input bytes are available */
105 inline void check (int num)
108 throw_class_format_error ("Premature end of data");
111 /* skip a given number of bytes in input */
112 inline void skip (int num)
118 /* read an unsignend 1-byte unit */
119 inline static jint get1u (unsigned char* bytes)
124 /* read an unsigned 1-byte unit */
125 inline jint read1u ()
128 return get1u (bytes+pos-1);
131 /* read an unsigned 2-byte unit */
132 inline static jint get2u (unsigned char *bytes)
134 return (((jint)bytes[0]) << 8) | ((jint)bytes[1]);
137 /* read an unsigned 2-byte unit */
138 inline jint read2u ()
141 return get2u (bytes+pos-2);
144 /* read a 4-byte unit */
145 static jint get4 (unsigned char *bytes)
147 return (((jint)bytes[0]) << 24)
148 | (((jint)bytes[1]) << 16)
149 | (((jint)bytes[2]) << 8)
150 | (((jint)bytes[3]) << 0);
153 /* read a 4-byte unit, (we don't do that quite so often) */
157 return get4 (bytes+pos-4);
160 /* read a 8-byte unit */
161 static jlong get8 (unsigned char* bytes)
163 return (((jlong)bytes[0]) << 56)
164 | (((jlong)bytes[1]) << 48)
165 | (((jlong)bytes[2]) << 40)
166 | (((jlong)bytes[3]) << 32)
167 | (((jlong)bytes[4]) << 24)
168 | (((jlong)bytes[5]) << 16)
169 | (((jlong)bytes[6]) << 8)
170 | (((jlong)bytes[7]) << 0);
173 /* read a 8-byte unit */
174 inline jlong read8 ()
177 return get8 (bytes+pos-8);
180 inline void check_tag (int index, char expected_tag)
183 || index > pool_count
184 || tags[index] != expected_tag)
185 throw_class_format_error ("erroneous constant pool tag");
188 inline void verify_identifier (_Jv_Utf8Const* name)
190 if (! _Jv_VerifyIdentifier (name))
191 throw_class_format_error ("erroneous identifier");
194 inline void verify_classname (unsigned char* ptr, _Jv_ushort length)
196 if (! _Jv_VerifyClassName (ptr, length))
197 throw_class_format_error ("erroneous class name");
200 inline void verify_classname (_Jv_Utf8Const *name)
202 if (! _Jv_VerifyClassName (name))
203 throw_class_format_error ("erroneous class name");
206 inline void verify_field_signature (_Jv_Utf8Const *sig)
208 if (! _Jv_VerifyFieldSignature (sig))
209 throw_class_format_error ("erroneous type descriptor");
212 inline void verify_method_signature (_Jv_Utf8Const *sig)
214 if (! _Jv_VerifyMethodSignature (sig))
215 throw_class_format_error ("erroneous type descriptor");
218 _Jv_ClassReader (jclass klass, jbyteArray data, jint offset, jint length)
220 if (klass == 0 || length < 0 || offset+length > data->length)
221 throw_internal_error ("arguments to _Jv_DefineClass");
224 bytes = (unsigned char*) (elements (data)+offset);
228 def_interp = (_Jv_InterpClass *) def->aux_info;
231 /** and here goes the parser members defined out-of-line */
233 void read_constpool ();
234 void prepare_pool_entry (int index, unsigned char tag);
236 void read_methods ();
237 void read_one_class_attribute ();
238 void read_one_method_attribute (int method);
239 void read_one_code_attribute (int method);
240 void read_one_field_attribute (int field);
241 void throw_class_format_error (char *msg);
243 /** check an utf8 entry, without creating a Utf8Const object */
244 bool is_attribute_name (int index, char *name);
246 /** here goes the class-loader members defined out-of-line */
247 void handleConstantPool ();
248 void handleClassBegin (int, int, int);
249 void handleInterfacesBegin (int);
250 void handleInterface (int, int);
251 void handleFieldsBegin (int);
252 void handleField (int, int, int, int);
253 void handleFieldsEnd ();
254 void handleConstantValueAttribute (int,int);
255 void handleMethodsBegin (int);
256 void handleMethod (int, int, int, int);
257 void handleMethodsEnd ();
258 void handleCodeAttribute (int, int, int, int, int, int);
259 void handleExceptionTableEntry (int, int, int, int, int, int);
261 void checkExtends (jclass sub, jclass super);
262 void checkImplements (jclass sub, jclass super);
265 * FIXME: we should keep a hash table of utf8-strings, since many will
266 * be the same. It's a little tricky, however, because the hash table
267 * needs to interact gracefully with the garbage collector. Much
268 * memory is to be saved by this, however! perhaps the improvement
269 * could be implemented in prims.cc (_Jv_makeUtf8Const), since it
270 * computes the hash value anyway.
275 _Jv_DefineClass (jclass klass, jbyteArray data, jint offset, jint length)
277 _Jv_ClassReader reader (klass, data, offset, length);
284 /** This section defines the parsing/scanning of the class data */
287 _Jv_ClassReader::parse ()
289 int magic = read4 ();
291 /* FIXME: Decide which range of version numbers to allow */
293 /* int minor_version = */ read2u ();
294 /* int major_verson = */ read2u ();
296 if (magic != (int) 0xCAFEBABE)
297 throw_class_format_error ("bad magic number");
299 pool_count = read2u ();
303 int access_flags = read2u ();
304 int this_class = read2u ();
305 int super_class = read2u ();
307 check_tag (this_class, JV_CONSTANT_Class);
308 if (super_class != 0)
309 check_tag (super_class, JV_CONSTANT_Class);
311 handleClassBegin (access_flags, this_class, super_class);
313 int interfaces_count = read2u ();
315 handleInterfacesBegin (interfaces_count);
317 for (int i = 0; i < interfaces_count; i++)
319 int iface = read2u ();
320 check_tag (iface, JV_CONSTANT_Class);
321 handleInterface (i, iface);
327 int attributes_count = read2u ();
329 for (int i = 0; i < attributes_count; i++)
331 read_one_class_attribute ();
335 throw_class_format_error ("unused data before end of file");
337 // tell everyone we're done.
338 def->state = JV_STATE_LOADED;
339 if (gcj::verbose_class_flag)
340 fprintf (stderr, "[Loaded (bytecode) %s]\n", def->name->chars());
345 void _Jv_ClassReader::read_constpool ()
347 tags = (unsigned char*) _Jv_AllocBytes (pool_count);
348 offsets = (unsigned int *) _Jv_AllocBytes (sizeof (int)
351 /** first, we scan the constant pool, collecting tags and offsets */
352 tags[0] = JV_CONSTANT_Undefined;
354 for (int c = 1; c < pool_count; c++)
361 case JV_CONSTANT_String:
362 case JV_CONSTANT_Class:
366 case JV_CONSTANT_Fieldref:
367 case JV_CONSTANT_Methodref:
368 case JV_CONSTANT_InterfaceMethodref:
369 case JV_CONSTANT_NameAndType:
370 case JV_CONSTANT_Integer:
371 case JV_CONSTANT_Float:
375 case JV_CONSTANT_Double:
376 case JV_CONSTANT_Long:
378 tags[++c] = JV_CONSTANT_Undefined;
381 case JV_CONSTANT_Utf8:
388 case JV_CONSTANT_Unicode:
389 throw_class_format_error ("unicode not supported");
393 throw_class_format_error ("erroneous constant pool tag");
397 handleConstantPool ();
401 void _Jv_ClassReader::read_fields ()
403 int fields_count = read2u ();
404 handleFieldsBegin (fields_count);
406 for (int i = 0; i < fields_count; i++)
408 int access_flags = read2u ();
409 int name_index = read2u ();
410 int descriptor_index = read2u ();
411 int attributes_count = read2u ();
413 check_tag (name_index, JV_CONSTANT_Utf8);
414 prepare_pool_entry (name_index, JV_CONSTANT_Utf8);
416 check_tag (descriptor_index, JV_CONSTANT_Utf8);
417 prepare_pool_entry (descriptor_index, JV_CONSTANT_Utf8);
419 handleField (i, access_flags, name_index, descriptor_index);
421 for (int j = 0; j < attributes_count; j++)
423 read_one_field_attribute (i);
431 _Jv_ClassReader::is_attribute_name (int index, char *name)
433 check_tag (index, JV_CONSTANT_Utf8);
434 int len = get2u (bytes+offsets[index]);
435 if (len != (int) strlen (name))
438 return !memcmp (bytes+offsets[index]+2, name, len);
441 void _Jv_ClassReader::read_one_field_attribute (int field_index)
443 int name = read2u ();
444 int length = read4 ();
446 if (is_attribute_name (name, "ConstantValue"))
452 && (tags[cv] == JV_CONSTANT_Integer
453 || tags[cv] == JV_CONSTANT_Float
454 || tags[cv] == JV_CONSTANT_Long
455 || tags[cv] == JV_CONSTANT_Double
456 || tags[cv] == JV_CONSTANT_String))
458 handleConstantValueAttribute (field_index, cv);
462 throw_class_format_error ("erroneous ConstantValue attribute");
466 throw_class_format_error ("erroneous ConstantValue attribute");
475 void _Jv_ClassReader::read_methods ()
477 int methods_count = read2u ();
479 handleMethodsBegin (methods_count);
481 for (int i = 0; i < methods_count; i++)
483 int access_flags = read2u ();
484 int name_index = read2u ();
485 int descriptor_index = read2u ();
486 int attributes_count = read2u ();
488 check_tag (name_index, JV_CONSTANT_Utf8);
489 prepare_pool_entry (descriptor_index, JV_CONSTANT_Utf8);
491 check_tag (name_index, JV_CONSTANT_Utf8);
492 prepare_pool_entry (descriptor_index, JV_CONSTANT_Utf8);
494 handleMethod (i, access_flags, name_index,
497 for (int j = 0; j < attributes_count; j++)
499 read_one_method_attribute (i);
506 void _Jv_ClassReader::read_one_method_attribute (int method_index)
508 int name = read2u ();
509 int length = read4 ();
511 if (is_attribute_name (name, "Exceptions"))
513 _Jv_Method *method = reinterpret_cast<_Jv_Method *>
514 (&def->methods[method_index]);
515 if (method->throws != NULL)
516 throw_class_format_error ("only one Exceptions attribute allowed per method");
518 int num_exceptions = read2u ();
519 // We use malloc here because the GC won't scan the method
520 // objects. FIXME this means a memory leak if we GC a class.
521 // (Currently we never do.)
522 _Jv_Utf8Const **exceptions =
523 (_Jv_Utf8Const **) _Jv_Malloc ((num_exceptions + 1) * sizeof (_Jv_Utf8Const *));
526 _Jv_word *pool_data = def->constants.data;
527 for (int i = 0; i < num_exceptions; ++i)
532 // JLS 2nd Ed. 4.7.5 requires that the tag not be 0.
535 check_tag (ndx, JV_CONSTANT_Class);
536 exceptions[out++] = pool_data[ndx].utf8;
539 catch (java::lang::Throwable *exc)
541 _Jv_Free (exceptions);
545 exceptions[out] = NULL;
546 method->throws = exceptions;
549 else if (is_attribute_name (name, "Code"))
552 int max_stack = read2u ();
553 int max_locals = read2u ();
554 int code_length = read4 ();
556 int code_start = pos;
558 int exception_table_length = read2u ();
560 handleCodeAttribute (method_index,
561 max_stack, max_locals,
562 code_start, code_length,
563 exception_table_length);
566 for (int i = 0; i < exception_table_length; i++)
568 int start_pc = read2u ();
569 int end_pc = read2u ();
570 int handler_pc = read2u ();
571 int catch_type = read2u ();
573 if (start_pc > end_pc
575 // END_PC can be equal to CODE_LENGTH.
576 // See JVM Spec 4.7.4.
577 || end_pc > code_length
578 || handler_pc >= code_length)
579 throw_class_format_error ("erroneous exception handler info");
581 if (! (tags[catch_type] == JV_CONSTANT_Class
582 || tags[catch_type] == 0))
584 throw_class_format_error ("erroneous exception handler info");
587 handleExceptionTableEntry (method_index,
596 int attributes_count = read2u ();
598 for (int i = 0; i < attributes_count; i++)
600 read_one_code_attribute (method_index);
603 if ((pos - start_off) != length)
604 throw_class_format_error ("code attribute too short");
609 /* ignore unknown attributes */
614 void _Jv_ClassReader::read_one_code_attribute (int /*method*/)
616 /* ignore for now, ... later we may want to pick up
617 line number information, for debugging purposes;
618 in fact, the whole debugger issue is open! */
620 /* int name = */ read2u ();
621 int length = read4 ();
626 void _Jv_ClassReader::read_one_class_attribute ()
628 /* we also ignore the class attributes, ...
629 some day we'll add inner-classes support. */
631 /* int name = */ read2u ();
632 int length = read4 ();
639 /* this section defines the semantic actions of the parser */
641 void _Jv_ClassReader::handleConstantPool ()
643 /** now, we actually define the class' constant pool */
645 // the pool is scanned explicitly by the collector
646 jbyte *pool_tags = (jbyte*) _Jv_AllocBytes (pool_count);
648 = (_Jv_word*) _Jv_AllocBytes (pool_count * sizeof (_Jv_word));
650 def->constants.tags = pool_tags;
651 def->constants.data = pool_data;
652 def->constants.size = pool_count;
654 // Here we make a pass to collect the strings! We do this, because
655 // internally in the GCJ runtime, classes are encoded with .'s not /'s.
656 // Therefore, we first collect the strings, and then translate the rest
657 // of the utf8-entries (thus not representing strings) from /-notation
659 for (int i = 1; i < pool_count; i++)
661 if (tags[i] == JV_CONSTANT_String)
663 unsigned char* str_data = bytes + offsets [i];
664 int utf_index = get2u (str_data);
665 check_tag (utf_index, JV_CONSTANT_Utf8);
666 unsigned char *utf_data = bytes + offsets[utf_index];
667 int len = get2u (utf_data);
668 pool_data[i].utf8 = _Jv_makeUtf8Const ((char*)(utf_data+2), len);
669 pool_tags[i] = JV_CONSTANT_String;
673 pool_tags[i] = JV_CONSTANT_Undefined;
677 // and now, we scan everything else but strings & utf8-entries. This
678 // leaves out those utf8-entries which are not used; which will be left
679 // with a tag of JV_CONSTANT_Undefined in the class definition.
680 for (int index = 1; index < pool_count; index++)
684 case JV_CONSTANT_Undefined:
685 case JV_CONSTANT_String:
686 case JV_CONSTANT_Utf8:
690 prepare_pool_entry (index, tags[index]);
696 /* this is a recursive procedure, which will prepare pool entries as needed.
697 Which is how we avoid initializing those entries which go unused. */
699 _Jv_ClassReader::prepare_pool_entry (int index, unsigned char this_tag)
701 /* these two, pool_data and pool_tags, point into the class
702 structure we are currently defining */
704 unsigned char *pool_tags = (unsigned char*) def->constants.tags;
705 _Jv_word *pool_data = def->constants.data;
707 /* this entry was already prepared */
708 if (pool_tags[index] == this_tag)
711 /* this_data points to the constant-pool information for the current
712 constant-pool entry */
714 unsigned char *this_data = bytes + offsets[index];
718 case JV_CONSTANT_Utf8:
720 // If we came here, it is because some other tag needs this
721 // utf8-entry for type information! Thus, we translate /'s to .'s in
722 // order to accomondate gcj's internal representation.
724 int len = get2u (this_data);
725 char *buffer = (char*) __builtin_alloca (len);
726 char *s = ((char*) this_data)+2;
728 /* FIXME: avoid using a buffer here */
729 for (int i = 0; i < len; i++)
734 buffer[i] = (char) s[i];
737 pool_data[index].utf8 = _Jv_makeUtf8Const (buffer, len);
738 pool_tags[index] = JV_CONSTANT_Utf8;
742 case JV_CONSTANT_Class:
744 int utf_index = get2u (this_data);
745 check_tag (utf_index, JV_CONSTANT_Utf8);
746 prepare_pool_entry (utf_index, JV_CONSTANT_Utf8);
749 verify_classname (pool_data[utf_index].utf8);
751 pool_data[index].utf8 = pool_data[utf_index].utf8;
752 pool_tags[index] = JV_CONSTANT_Class;
756 case JV_CONSTANT_String:
757 // already handled before...
760 case JV_CONSTANT_Fieldref:
761 case JV_CONSTANT_Methodref:
762 case JV_CONSTANT_InterfaceMethodref:
764 int class_index = get2u (this_data);
765 int nat_index = get2u (this_data+2);
767 check_tag (class_index, JV_CONSTANT_Class);
768 prepare_pool_entry (class_index, JV_CONSTANT_Class);
770 check_tag (nat_index, JV_CONSTANT_NameAndType);
771 prepare_pool_entry (nat_index, JV_CONSTANT_NameAndType);
773 // here, verify the signature and identifier name
776 _Jv_ushort name_index, type_index;
777 _Jv_loadIndexes (&pool_data[nat_index],
778 name_index, type_index);
780 if (this_tag == JV_CONSTANT_Fieldref)
781 verify_field_signature (pool_data[type_index].utf8);
783 verify_method_signature (pool_data[type_index].utf8);
785 _Jv_Utf8Const* name = pool_data[name_index].utf8;
787 if (this_tag != JV_CONSTANT_Fieldref
788 && ( _Jv_equalUtf8Consts (name, clinit_name)
789 || _Jv_equalUtf8Consts (name, init_name)))
792 verify_identifier (pool_data[name_index].utf8);
795 _Jv_storeIndexes (&pool_data[index], class_index, nat_index);
796 pool_tags[index] = this_tag;
800 case JV_CONSTANT_NameAndType:
802 _Jv_ushort name_index = get2u (this_data);
803 _Jv_ushort type_index = get2u (this_data+2);
805 check_tag (name_index, JV_CONSTANT_Utf8);
806 prepare_pool_entry (name_index, JV_CONSTANT_Utf8);
808 check_tag (type_index, JV_CONSTANT_Utf8);
809 prepare_pool_entry (type_index, JV_CONSTANT_Utf8);
811 _Jv_storeIndexes (&pool_data[index], name_index, type_index);
812 pool_tags[index] = JV_CONSTANT_NameAndType;
816 case JV_CONSTANT_Float:
818 jfloat f = java::lang::Float::intBitsToFloat ((jint) get4 (this_data));
819 _Jv_storeFloat (&pool_data[index], f);
820 pool_tags[index] = JV_CONSTANT_Float;
824 case JV_CONSTANT_Integer:
826 int i = get4 (this_data);
827 _Jv_storeInt (&pool_data[index], i);
828 pool_tags[index] = JV_CONSTANT_Integer;
832 case JV_CONSTANT_Double:
835 = java::lang::Double::longBitsToDouble ((jlong) get8 (this_data));
836 _Jv_storeDouble (&pool_data[index], d);
837 pool_tags[index] = JV_CONSTANT_Double;
841 case JV_CONSTANT_Long:
843 jlong i = get8 (this_data);
844 _Jv_storeLong (&pool_data[index], i);
845 pool_tags[index] = JV_CONSTANT_Long;
850 throw_class_format_error ("erroneous constant pool tag");
856 _Jv_ClassReader::handleClassBegin
857 (int access_flags, int this_class, int super_class)
859 using namespace java::lang::reflect;
861 unsigned char *pool_tags = (unsigned char*) def->constants.tags;
862 _Jv_word *pool_data = def->constants.data;
864 check_tag (this_class, JV_CONSTANT_Class);
865 _Jv_Utf8Const *loadedName = pool_data[this_class].utf8;
867 // was ClassLoader.defineClass called with an expected class name?
870 jclass orig = _Jv_FindClassInCache (loadedName, def->loader);
874 def->name = loadedName;
878 jstring msg = JvNewStringUTF ("anonymous "
879 "class data denotes "
881 msg = msg->concat (orig->getName ());
883 throw_no_class_def_found_error (msg);
887 // assert that the loaded class has the expected name, 5.3.5
888 else if (! _Jv_equalUtf8Consts (loadedName, def->name))
890 jstring msg = JvNewStringUTF ("loaded class ");
891 msg = msg->concat (def->getName ());
892 msg = msg->concat (_Jv_NewStringUTF (" was in fact named "));
893 jstring klass_name = loadedName->toString();
894 msg = msg->concat (klass_name);
896 throw_no_class_def_found_error (msg);
899 def->accflags = access_flags | java::lang::reflect::Modifier::INTERPRETED;
900 pool_data[this_class].clazz = def;
901 pool_tags[this_class] = JV_CONSTANT_ResolvedClass;
903 if (super_class == 0 && ! (access_flags & Modifier::INTERFACE))
905 // FIXME: Consider this carefully!
906 if (! _Jv_equalUtf8Consts (def->name, java::lang::Object::class$.name))
907 throw_no_class_def_found_error ("loading java.lang.Object");
910 // In the pre-loading state, it can be looked up in the
911 // cache only by this thread! This allows the super-class
912 // to include references to this class.
914 def->state = JV_STATE_PRELOADING;
917 JvSynchronize sync (&java::lang::Class::class$);
918 _Jv_RegisterClass (def);
921 if (super_class != 0)
923 // Load the superclass.
924 check_tag (super_class, JV_CONSTANT_Class);
925 _Jv_Utf8Const* super_name = pool_data[super_class].utf8;
927 // Load the superclass using our defining loader.
928 jclass the_super = _Jv_FindClass (super_name,
931 // This will establish that we are allowed to be a subclass,
932 // and check for class circularity error.
933 checkExtends (def, the_super);
935 // Note: for an interface we will find Object as the
936 // superclass. We still check it above to ensure class file
937 // validity, but we simply assign `null' to the actual field in
939 def->superclass = (((access_flags & Modifier::INTERFACE))
941 pool_data[super_class].clazz = the_super;
942 pool_tags[super_class] = JV_CONSTANT_ResolvedClass;
945 // Now we've come past the circularity problem, we can
946 // now say that we're loading.
948 def->state = JV_STATE_LOADING;
952 ///// implements the checks described in sect. 5.3.5.3
954 _Jv_ClassReader::checkExtends (jclass sub, jclass super)
956 using namespace java::lang::reflect;
958 // having an interface or a final class as a superclass is no good
959 if ((super->accflags & (Modifier::INTERFACE | Modifier::FINAL)) != 0)
961 throw_incompatible_class_change_error (sub->getName ());
964 // if the super class is not public, we need to check some more
965 if ((super->accflags & Modifier::PUBLIC) == 0)
967 // With package scope, the classes must have the same
969 if ( sub->loader != super->loader
970 || !_Jv_ClassNameSamePackage (sub->name, super->name))
972 throw_incompatible_class_change_error (sub->getName ());
976 for (; super != 0; super = super->superclass)
979 throw_class_circularity_error (sub->getName ());
985 void _Jv_ClassReader::handleInterfacesBegin (int count)
987 def->interfaces = (jclass*) _Jv_AllocBytes (count*sizeof (jclass));
988 def->interface_count = count;
991 void _Jv_ClassReader::handleInterface (int if_number, int offset)
993 _Jv_word * pool_data = def->constants.data;
994 unsigned char * pool_tags = (unsigned char*) def->constants.tags;
996 jclass the_interface;
998 if (pool_tags[offset] == JV_CONSTANT_Class)
1000 _Jv_Utf8Const* name = pool_data[offset].utf8;
1001 the_interface = _Jv_FindClass (name, def->loader);
1003 else if (pool_tags[offset] == JV_CONSTANT_ResolvedClass)
1005 the_interface = pool_data[offset].clazz;
1009 throw_no_class_def_found_error ("erroneous constant pool tag");
1012 // checks the validity of the_interface, and that we are in fact
1013 // allowed to implement that interface.
1014 checkImplements (def, the_interface);
1016 pool_data[offset].clazz = the_interface;
1017 pool_tags[offset] = JV_CONSTANT_ResolvedClass;
1019 def->interfaces[if_number] = the_interface;
1023 _Jv_ClassReader::checkImplements (jclass sub, jclass super)
1025 using namespace java::lang::reflect;
1027 // well, it *must* be an interface
1028 if ((super->accflags & Modifier::INTERFACE) == 0)
1030 throw_incompatible_class_change_error (sub->getName ());
1033 // if it has package scope, it must also be defined by the
1035 if ((super->accflags & Modifier::PUBLIC) == 0)
1037 if ( sub->loader != super->loader
1038 || !_Jv_ClassNameSamePackage (sub->name, super->name))
1040 throw_incompatible_class_change_error (sub->getName ());
1044 // FIXME: add interface circularity check here
1047 throw_class_circularity_error (sub->getName ());
1051 void _Jv_ClassReader::handleFieldsBegin (int count)
1053 def->fields = (_Jv_Field*)
1054 _Jv_AllocBytes (count * sizeof (_Jv_Field));
1055 def->field_count = count;
1056 def_interp->field_initializers = (_Jv_ushort*)
1057 _Jv_AllocBytes (count * sizeof (_Jv_ushort));
1058 for (int i = 0; i < count; i++)
1059 def_interp->field_initializers[i] = (_Jv_ushort) 0;
1062 void _Jv_ClassReader::handleField (int field_no,
1067 using namespace java::lang::reflect;
1069 _Jv_word *pool_data = def->constants.data;
1071 _Jv_Field *field = &def->fields[field_no];
1072 _Jv_Utf8Const *field_name = pool_data[name].utf8;
1074 #ifndef COMPACT_FIELDS
1075 field->name = field_name;
1077 field->nameIndex = name;
1080 // Ignore flags we don't know about.
1081 field->flags = flags & Modifier::ALL_FLAGS;
1083 _Jv_Utf8Const* sig = pool_data[desc].utf8;
1087 verify_identifier (field_name);
1089 for (int i = 0; i < field_no; ++i)
1091 if (_Jv_equalUtf8Consts (field_name, def->fields[i].name)
1092 && _Jv_equalUtf8Consts (sig,
1093 // We know the other fields are
1095 (_Jv_Utf8Const *) def->fields[i].type))
1096 throw_class_format_error ("duplicate field name");
1099 // At most one of PUBLIC, PRIVATE, or PROTECTED is allowed.
1100 if (1 < ( ((field->flags & Modifier::PUBLIC) ? 1 : 0)
1101 +((field->flags & Modifier::PRIVATE) ? 1 : 0)
1102 +((field->flags & Modifier::PROTECTED) ? 1 : 0)))
1103 throw_class_format_error ("erroneous field access flags");
1105 // FIXME: JVM spec S4.5: Verify ACC_FINAL and ACC_VOLATILE are not
1106 // both set. Verify modifiers for interface fields.
1111 verify_field_signature (sig);
1113 // field->type is really a jclass, but while it is still
1114 // unresolved we keep an _Jv_Utf8Const* instead.
1115 field->type = (jclass) sig;
1116 field->flags |= _Jv_FIELD_UNRESOLVED_FLAG;
1117 field->u.boffset = 0;
1121 void _Jv_ClassReader::handleConstantValueAttribute (int field_index,
1124 using namespace java::lang::reflect;
1126 _Jv_Field *field = &def->fields[field_index];
1128 if ((field->flags & (Modifier::STATIC
1130 | Modifier::PRIVATE)) == 0)
1132 // Ignore, as per vmspec #4.7.2
1136 // do not allow multiple constant fields!
1137 if (field->flags & _Jv_FIELD_CONSTANT_VALUE)
1138 throw_class_format_error ("field has multiple ConstantValue attributes");
1140 field->flags |= _Jv_FIELD_CONSTANT_VALUE;
1141 def_interp->field_initializers[field_index] = value;
1143 /* type check the initializer */
1145 if (value <= 0 || value >= pool_count)
1146 throw_class_format_error ("erroneous ConstantValue attribute");
1148 /* FIXME: do the rest */
1151 void _Jv_ClassReader::handleFieldsEnd ()
1153 using namespace java::lang::reflect;
1155 // We need to reorganize the fields so that the static ones are first,
1156 // to conform to GCJ class layout.
1159 int high = def->field_count-1;
1160 _Jv_Field *fields = def->fields;
1161 _Jv_ushort *inits = def_interp->field_initializers;
1163 // this is kind of a raw version of quicksort.
1166 // go forward on low, while it's a static
1167 while (low < high && (fields[low].flags & Modifier::STATIC) != 0)
1170 // go backwards on high, while it's a non-static
1171 while (low < high && (fields[high].flags & Modifier::STATIC) == 0)
1177 _Jv_Field tmp = fields[low];
1178 _Jv_ushort itmp = inits[low];
1180 fields[low] = fields[high];
1181 inits[low] = inits[high];
1190 if ((fields[low].flags & Modifier::STATIC) != 0)
1193 def->static_field_count = low;
1199 _Jv_ClassReader::handleMethodsBegin (int count)
1201 def->methods = (_Jv_Method *) _Jv_AllocBytes (sizeof (_Jv_Method) * count);
1203 def_interp->interpreted_methods
1204 = (_Jv_MethodBase **) _Jv_AllocBytes (sizeof (_Jv_MethodBase *)
1207 for (int i = 0; i < count; i++)
1209 def_interp->interpreted_methods[i] = 0;
1210 def->methods[i].index = (_Jv_ushort) -1;
1213 def->method_count = count;
1217 void _Jv_ClassReader::handleMethod
1218 (int mth_index, int accflags, int name, int desc)
1220 using namespace java::lang::reflect;
1222 _Jv_word *pool_data = def->constants.data;
1223 _Jv_Method *method = &def->methods[mth_index];
1225 check_tag (name, JV_CONSTANT_Utf8);
1226 prepare_pool_entry (name, JV_CONSTANT_Utf8);
1227 method->name = pool_data[name].utf8;
1229 check_tag (desc, JV_CONSTANT_Utf8);
1230 prepare_pool_entry (desc, JV_CONSTANT_Utf8);
1231 method->signature = pool_data[desc].utf8;
1233 // ignore unknown flags
1234 method->accflags = accflags & Modifier::ALL_FLAGS;
1238 method->throws = NULL;
1242 if (_Jv_equalUtf8Consts (method->name, clinit_name)
1243 || _Jv_equalUtf8Consts (method->name, init_name))
1246 verify_identifier (method->name);
1248 verify_method_signature (method->signature);
1250 for (int i = 0; i < mth_index; ++i)
1252 if (_Jv_equalUtf8Consts (method->name, def->methods[i].name)
1253 && _Jv_equalUtf8Consts (method->signature,
1254 def->methods[i].signature))
1255 throw_class_format_error ("duplicate method");
1258 // At most one of PUBLIC, PRIVATE, or PROTECTED is allowed.
1259 if (1 < ( ((method->accflags & Modifier::PUBLIC) ? 1 : 0)
1260 +((method->accflags & Modifier::PRIVATE) ? 1 : 0)
1261 +((method->accflags & Modifier::PROTECTED) ? 1 : 0)))
1262 throw_class_format_error ("erroneous method access flags");
1264 // FIXME: JVM spec S4.6: if ABSTRACT modifier is set, verify other
1265 // flags are not set. Verify flags for interface methods. Verifiy
1266 // modifiers for initializers.
1270 void _Jv_ClassReader::handleCodeAttribute
1271 (int method_index, int max_stack, int max_locals,
1272 int code_start, int code_length, int exc_table_length)
1274 int size = _Jv_InterpMethod::size (exc_table_length, code_length);
1275 _Jv_InterpMethod *method =
1276 (_Jv_InterpMethod*) (_Jv_AllocBytes (size));
1278 method->deferred = NULL;
1279 method->max_stack = max_stack;
1280 method->max_locals = max_locals;
1281 method->code_length = code_length;
1282 method->exc_count = exc_table_length;
1283 method->defining_class = def;
1284 method->self = &def->methods[method_index];
1285 method->prepared = NULL;
1287 // grab the byte code!
1288 memcpy ((void*) method->bytecode (),
1289 (void*) (bytes+code_start),
1292 def_interp->interpreted_methods[method_index] = method;
1294 if ((method->self->accflags & java::lang::reflect::Modifier::STATIC))
1296 // Precompute the ncode field for a static method. This lets us
1297 // call a static method of an interpreted class from precompiled
1298 // code without first resolving the class (that will happen
1299 // during class initialization instead).
1300 method->self->ncode = method->ncode ();
1304 void _Jv_ClassReader::handleExceptionTableEntry
1305 (int method_index, int exc_index,
1306 int start_pc, int end_pc, int handler_pc, int catch_type)
1308 _Jv_InterpMethod *method = reinterpret_cast<_Jv_InterpMethod *>
1309 (def_interp->interpreted_methods[method_index]);
1310 _Jv_InterpException *exc = method->exceptions ();
1312 exc[exc_index].start_pc.i = start_pc;
1313 exc[exc_index].end_pc.i = end_pc;
1314 exc[exc_index].handler_pc.i = handler_pc;
1315 exc[exc_index].handler_type.i = catch_type;
1318 void _Jv_ClassReader::handleMethodsEnd ()
1320 using namespace java::lang::reflect;
1322 for (int i = 0; i < def->method_count; i++)
1324 _Jv_Method *method = &def->methods[i];
1325 if ((method->accflags & Modifier::NATIVE) != 0)
1327 if (def_interp->interpreted_methods[i] != 0)
1328 throw_class_format_error ("code provided for native method");
1331 _Jv_JNIMethod *m = (_Jv_JNIMethod *)
1332 _Jv_AllocBytes (sizeof (_Jv_JNIMethod));
1333 m->defining_class = def;
1336 def_interp->interpreted_methods[i] = m;
1339 if ((method->accflags & Modifier::STATIC))
1341 // Precompute the ncode field for a static method.
1342 // This lets us call a static method of an
1343 // interpreted class from precompiled code without
1344 // first resolving the class (that will happen
1345 // during class initialization instead).
1346 method->ncode = m->ncode ();
1350 else if ((method->accflags & Modifier::ABSTRACT) != 0)
1352 if (def_interp->interpreted_methods[i] != 0)
1353 throw_class_format_error ("code provided for abstract method");
1357 if (def_interp->interpreted_methods[i] == 0)
1358 throw_class_format_error ("method with no code");
1363 void _Jv_ClassReader::throw_class_format_error (char *msg)
1366 if (def->name != NULL)
1368 jsize mlen = strlen (msg);
1369 unsigned char* data = (unsigned char*) def->name->chars();
1370 int ulen = def->name->len();
1371 unsigned char* limit = data + ulen;
1372 jsize nlen = _Jv_strLengthUtf8 ((char *) data, ulen);
1373 jsize len = nlen + mlen + 3;
1374 str = JvAllocString(len);
1375 jchar *chrs = JvGetStringChars(str);
1376 while (data < limit)
1377 *chrs++ = UTF8_GET(data, limit);
1385 *chrs++ = c & 0xFFFF;
1390 str = JvNewStringLatin1 (msg);
1391 ::throw_class_format_error (str);
1394 /** Here we define the exceptions that can be thrown */
1397 throw_no_class_def_found_error (jstring msg)
1400 ? new java::lang::NoClassDefFoundError (msg)
1401 : new java::lang::NoClassDefFoundError);
1405 throw_no_class_def_found_error (char *msg)
1407 throw_no_class_def_found_error (JvNewStringLatin1 (msg));
1411 throw_class_format_error (jstring msg)
1414 ? new java::lang::ClassFormatError (msg)
1415 : new java::lang::ClassFormatError);
1419 throw_internal_error (char *msg)
1421 throw new java::lang::InternalError (JvNewStringLatin1 (msg));
1425 throw_incompatible_class_change_error (jstring msg)
1427 throw new java::lang::IncompatibleClassChangeError (msg);
1431 throw_class_circularity_error (jstring msg)
1433 throw new java::lang::ClassCircularityError (msg);
1436 #endif /* INTERPRETER */
1440 /** This section takes care of verifying integrity of identifiers,
1441 signatures, field ddescriptors, and class names */
1443 #define UTF8_PEEK(PTR, LIMIT) \
1444 ({ unsigned char* xxkeep = (PTR); \
1445 int xxch = UTF8_GET(PTR,LIMIT); \
1446 PTR = xxkeep; xxch; })
1448 /* Verify one element of a type descriptor or signature. */
1449 static unsigned char*
1450 _Jv_VerifyOne (unsigned char* ptr, unsigned char* limit, bool void_ok)
1455 int ch = UTF8_GET (ptr, limit);
1463 case 'S': case 'B': case 'I': case 'J':
1464 case 'Z': case 'C': case 'F': case 'D':
1469 unsigned char *start = ptr, *end;
1477 if ((ch = UTF8_GET (ptr, limit)) == -1)
1482 if (! _Jv_VerifyClassName (start, (unsigned short) (end-start)))
1488 return _Jv_VerifyOne (ptr, limit, false);
1498 /* Verification and loading procedures. */
1500 _Jv_VerifyFieldSignature (_Jv_Utf8Const*sig)
1502 unsigned char* ptr = (unsigned char*) sig->chars();
1503 unsigned char* limit = ptr + sig->len();
1505 ptr = _Jv_VerifyOne (ptr, limit, false);
1507 return ptr == limit;
1511 _Jv_VerifyMethodSignature (_Jv_Utf8Const*sig)
1513 unsigned char* ptr = (unsigned char*) sig->chars();
1514 unsigned char* limit = ptr + sig->len();
1516 if (ptr == limit || UTF8_GET(ptr,limit) != '(')
1519 while (ptr && UTF8_PEEK (ptr, limit) != ')')
1520 ptr = _Jv_VerifyOne (ptr, limit, false);
1522 if (UTF8_GET (ptr, limit) != ')')
1525 // get the return type
1526 ptr = _Jv_VerifyOne (ptr, limit, true);
1528 return ptr == limit;
1531 /* We try to avoid calling the Character methods all the time, in
1532 fact, they will only be called for non-standard things. */
1533 static __inline__ int
1534 is_identifier_start (int c)
1536 unsigned int ch = (unsigned)c;
1538 if ((ch - 0x41U) < 29U) /* A ... Z */
1540 if ((ch - 0x61U) < 29U) /* a ... z */
1542 if (ch == 0x5FU) /* _ */
1545 return java::lang::Character::isJavaIdentifierStart ((jchar) ch);
1548 static __inline__ int
1549 is_identifier_part (int c)
1551 unsigned int ch = (unsigned)c;
1553 if ((ch - 0x41U) < 29U) /* A ... Z */
1555 if ((ch - 0x61U) < 29U) /* a ... z */
1557 if ((ch - 0x30) < 10U) /* 0 .. 9 */
1559 if (ch == 0x5FU || ch == 0x24U) /* _ $ */
1562 return java::lang::Character::isJavaIdentifierStart ((jchar) ch);
1566 _Jv_VerifyIdentifier (_Jv_Utf8Const* name)
1568 unsigned char *ptr = (unsigned char*) name->chars();
1569 unsigned char *limit = (unsigned char*) name->limit();
1572 if ((ch = UTF8_GET (ptr, limit))==-1
1573 || ! is_identifier_start (ch))
1576 while (ptr != limit)
1578 if ((ch = UTF8_GET (ptr, limit))==-1
1579 || ! is_identifier_part (ch))
1586 _Jv_VerifyClassName (unsigned char* ptr, _Jv_ushort length)
1588 unsigned char *limit = ptr+length;
1591 if ('[' == UTF8_PEEK (ptr, limit))
1593 unsigned char *end = _Jv_VerifyOne (++ptr, limit, false);
1594 // _Jv_VerifyOne must leave us looking at the terminating nul
1604 if ((ch = UTF8_GET (ptr, limit))==-1)
1606 if (! is_identifier_start (ch))
1611 else if ((ch = UTF8_GET (ptr, limit))==-1)
1615 else if (! is_identifier_part (ch))
1622 _Jv_VerifyClassName (_Jv_Utf8Const *name)
1624 return _Jv_VerifyClassName ((unsigned char*)name->chars(), name->len());
1627 /* Returns true, if NAME1 and NAME2 represent classes in the same
1630 _Jv_ClassNameSamePackage (_Jv_Utf8Const *name1, _Jv_Utf8Const *name2)
1632 unsigned char* ptr1 = (unsigned char*) name1->chars();
1633 unsigned char* limit1 = (unsigned char*) name1->limit();
1635 unsigned char* last1 = ptr1;
1637 // scan name1, and find the last occurrence of '.'
1638 while (ptr1 < limit1) {
1639 int ch1 = UTF8_GET (ptr1, limit1);
1648 // Now the length of NAME1's package name is LEN.
1649 int len = last1 - (unsigned char*) name1->chars();
1651 // If this is longer than NAME2, then we're off.
1652 if (len > name2->len())
1655 // Then compare the first len bytes for equality.
1656 if (memcmp ((void*) name1->chars(), (void*) name2->chars(), len) == 0)
1658 // Check that there are no .'s after position LEN in NAME2.
1660 unsigned char* ptr2 = (unsigned char*) name2->chars() + len;
1661 unsigned char* limit2 = (unsigned char*) name2->limit();
1663 while (ptr2 < limit2)
1665 int ch2 = UTF8_GET (ptr2, limit2);
1666 if (ch2 == -1 || ch2 == '.')