1 // defineclass.cc - defining a class from .class format.
3 /* Copyright (C) 2001, 2002 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
11 // Written by Tom Tromey <tromey@redhat.com>
13 // Define VERIFY_DEBUG to enable debugging output.
19 #include <java-insns.h>
20 #include <java-interp.h>
24 #include <java/lang/Class.h>
25 #include <java/lang/VerifyError.h>
26 #include <java/lang/Throwable.h>
27 #include <java/lang/reflect/Modifier.h>
28 #include <java/lang/StringBuffer.h>
32 #endif /* VERIFY_DEBUG */
35 static void debug_print (const char *fmt, ...)
36 __attribute__ ((format (printf, 1, 2)));
39 debug_print (const char *fmt, ...)
44 vfprintf (stderr, fmt, ap);
46 #endif /* VERIFY_DEBUG */
49 class _Jv_BytecodeVerifier
53 static const int FLAG_INSN_START = 1;
54 static const int FLAG_BRANCH_TARGET = 2;
59 struct subr_entry_info;
64 // The PC corresponding to the start of the current instruction.
67 // The current state of the stack, locals, etc.
70 // We store the state at branch targets, for merging. This holds
74 // We keep a linked list of all the PCs which we must reverify.
75 // The link is done using the PC values. This is the head of the
79 // We keep some flags for each instruction. The values are the
80 // FLAG_* constants defined above.
83 // We need to keep track of which instructions can call a given
84 // subroutine. FIXME: this is inefficient. We keep a linked list
85 // of all calling `jsr's at at each jsr target.
88 // We keep a linked list of entries which map each `ret' instruction
89 // to its unique subroutine entry point. We expect that there won't
90 // be many `ret' instructions, so a linked list is ok.
91 subr_entry_info *entry_points;
93 // The current top of the stack, in terms of slots.
95 // The current depth of the stack. This will be larger than
96 // STACKTOP when wide types are on the stack.
99 // The bytecode itself.
100 unsigned char *bytecode;
102 _Jv_InterpException *exception;
105 jclass current_class;
107 _Jv_InterpMethod *current_method;
109 // A linked list of utf8 objects we allocate. This is really ugly,
110 // but without this our utf8 objects would be collected.
111 linked_utf8 *utf8_list;
119 _Jv_Utf8Const *make_utf8_const (char *s, int len)
121 _Jv_Utf8Const *val = _Jv_makeUtf8Const (s, len);
122 _Jv_Utf8Const *r = (_Jv_Utf8Const *) _Jv_Malloc (sizeof (_Jv_Utf8Const)
125 r->length = val->length;
127 memcpy (r->data, val->data, val->length + 1);
129 linked_utf8 *lu = (linked_utf8 *) _Jv_Malloc (sizeof (linked_utf8));
131 lu->next = utf8_list;
137 // This enum holds a list of tags for all the different types we
138 // need to handle. Reference types are treated specially by the
144 // The values for primitive types are chosen to correspond to values
145 // specified to newarray.
155 // Used when overwriting second word of a double or long in the
156 // local variables. Also used after merging local variable states
157 // to indicate an unusable value.
162 // There is an obscure special case which requires us to note when
163 // a local variable has not been used by a subroutine. See
164 // push_jump_merge for more information.
165 unused_by_subroutine_type,
167 // Everything after `reference_type' must be a reference type.
170 unresolved_reference_type,
171 uninitialized_reference_type,
172 uninitialized_unresolved_reference_type
175 // Return the type_val corresponding to a primitive signature
176 // character. For instance `I' returns `int.class'.
177 type_val get_type_val_for_signature (jchar sig)
210 verify_fail ("invalid signature");
215 // Return the type_val corresponding to a primitive class.
216 type_val get_type_val_for_signature (jclass k)
218 return get_type_val_for_signature ((jchar) k->method_count);
221 // This is like _Jv_IsAssignableFrom, but it works even if SOURCE or
222 // TARGET haven't been prepared.
223 static bool is_assignable_from_slow (jclass target, jclass source)
225 // This will terminate when SOURCE==Object.
228 if (source == target)
231 if (target->isPrimitive () || source->isPrimitive ())
234 if (target->isArray ())
236 if (! source->isArray ())
238 target = target->getComponentType ();
239 source = source->getComponentType ();
241 else if (target->isInterface ())
243 for (int i = 0; i < source->interface_count; ++i)
245 // We use a recursive call because we also need to
246 // check superinterfaces.
247 if (is_assignable_from_slow (target, source->interfaces[i]))
250 source = source->getSuperclass ();
254 // We must do this check before we check to see if SOURCE is
255 // an interface. This way we know that any interface is
256 // assignable to an Object.
257 else if (target == &java::lang::Object::class$)
259 else if (source->isInterface ())
261 for (int i = 0; i < target->interface_count; ++i)
263 // We use a recursive call because we also need to
264 // check superinterfaces.
265 if (is_assignable_from_slow (target->interfaces[i], source))
268 target = target->getSuperclass ();
272 else if (source == &java::lang::Object::class$)
275 source = source->getSuperclass ();
279 // This is used to keep track of which `jsr's correspond to a given
283 // PC of the instruction just after the jsr.
289 // This is used to keep track of which subroutine entry point
290 // corresponds to which `ret' instruction.
291 struct subr_entry_info
293 // PC of the subroutine entry point.
295 // PC of the `ret' instruction.
298 subr_entry_info *next;
301 // The `type' class is used to represent a single type in the
307 // Some associated data.
310 // For a resolved reference type, this is a pointer to the class.
312 // For other reference types, this it the name of the class.
315 // This is used when constructing a new object. It is the PC of the
316 // `new' instruction which created the object. We use the special
317 // value -2 to mean that this is uninitialized, and the special
318 // value -1 for the case where the current method is itself the
322 static const int UNINIT = -2;
323 static const int SELF = -1;
325 // Basic constructor.
328 key = unsuitable_type;
333 // Make a new instance given the type tag. We assume a generic
334 // `reference_type' means Object.
339 if (key == reference_type)
340 data.klass = &java::lang::Object::class$;
344 // Make a new instance given a class.
347 key = reference_type;
352 // Make a new instance given the name of a class.
353 type (_Jv_Utf8Const *n)
355 key = unresolved_reference_type;
368 // These operators are required because libgcj can't link in
370 void *operator new[] (size_t bytes)
372 return _Jv_Malloc (bytes);
375 void operator delete[] (void *mem)
380 type& operator= (type_val k)
388 type& operator= (const type& t)
396 // Promote a numeric type.
399 if (key == boolean_type || key == char_type
400 || key == byte_type || key == short_type)
405 // If *THIS is an unresolved reference type, resolve it.
406 void resolve (_Jv_BytecodeVerifier *verifier)
408 if (key != unresolved_reference_type
409 && key != uninitialized_unresolved_reference_type)
412 using namespace java::lang;
413 java::lang::ClassLoader *loader
414 = verifier->current_class->getClassLoader();
415 // We might see either kind of name. Sigh.
416 if (data.name->data[0] == 'L'
417 && data.name->data[data.name->length - 1] == ';')
418 data.klass = _Jv_FindClassFromSignature (data.name->data, loader);
420 data.klass = Class::forName (_Jv_NewStringUtf8Const (data.name),
422 key = (key == unresolved_reference_type
424 : uninitialized_reference_type);
427 // Mark this type as the uninitialized result of `new'.
428 void set_uninitialized (int npc, _Jv_BytecodeVerifier *verifier)
430 if (key == reference_type)
431 key = uninitialized_reference_type;
432 else if (key == unresolved_reference_type)
433 key = uninitialized_unresolved_reference_type;
435 verifier->verify_fail ("internal error in type::uninitialized");
439 // Mark this type as now initialized.
440 void set_initialized (int npc)
442 if (npc != UNINIT && pc == npc
443 && (key == uninitialized_reference_type
444 || key == uninitialized_unresolved_reference_type))
446 key = (key == uninitialized_reference_type
448 : unresolved_reference_type);
454 // Return true if an object of type K can be assigned to a variable
455 // of type *THIS. Handle various special cases too. Might modify
456 // *THIS or K. Note however that this does not perform numeric
458 bool compatible (type &k, _Jv_BytecodeVerifier *verifier)
460 // Any type is compatible with the unsuitable type.
461 if (key == unsuitable_type)
464 if (key < reference_type || k.key < reference_type)
467 // The `null' type is convertible to any reference type.
468 // FIXME: is this correct for THIS?
469 if (key == null_type || k.key == null_type)
472 // Any reference type is convertible to Object. This is a special
473 // case so we don't need to unnecessarily resolve a class.
474 if (key == reference_type
475 && data.klass == &java::lang::Object::class$)
478 // An initialized type and an uninitialized type are not
480 if (isinitialized () != k.isinitialized ())
483 // Two uninitialized objects are compatible if either:
484 // * The PCs are identical, or
485 // * One PC is UNINIT.
486 if (! isinitialized ())
488 if (pc != k.pc && pc != UNINIT && k.pc != UNINIT)
492 // Two unresolved types are equal if their names are the same.
495 && _Jv_equalUtf8Consts (data.name, k.data.name))
498 // We must resolve both types and check assignability.
500 k.resolve (verifier);
501 return is_assignable_from_slow (data.klass, k.data.klass);
506 return key == void_type;
511 return key == long_type || key == double_type;
514 // Return number of stack or local variable slots taken by this
518 return iswide () ? 2 : 1;
521 bool isarray () const
523 // We treat null_type as not an array. This is ok based on the
524 // current uses of this method.
525 if (key == reference_type)
526 return data.klass->isArray ();
527 else if (key == unresolved_reference_type)
528 return data.name->data[0] == '[';
534 return key == null_type;
537 bool isinterface (_Jv_BytecodeVerifier *verifier)
540 if (key != reference_type)
542 return data.klass->isInterface ();
545 bool isabstract (_Jv_BytecodeVerifier *verifier)
548 if (key != reference_type)
550 using namespace java::lang::reflect;
551 return Modifier::isAbstract (data.klass->getModifiers ());
554 // Return the element type of an array.
555 type element_type (_Jv_BytecodeVerifier *verifier)
557 // FIXME: maybe should do string manipulation here.
559 if (key != reference_type)
560 verifier->verify_fail ("programmer error in type::element_type()", -1);
562 jclass k = data.klass->getComponentType ();
563 if (k->isPrimitive ())
564 return type (verifier->get_type_val_for_signature (k));
568 // Return the array type corresponding to an initialized
569 // reference. We could expand this to work for other kinds of
570 // types, but currently we don't need to.
571 type to_array (_Jv_BytecodeVerifier *verifier)
573 // Resolving isn't ideal, because it might force us to load
574 // another class, but it's easy. FIXME?
575 if (key == unresolved_reference_type)
578 if (key == reference_type)
579 return type (_Jv_GetArrayClass (data.klass,
580 data.klass->getClassLoader ()));
582 verifier->verify_fail ("internal error in type::to_array()");
585 bool isreference () const
587 return key >= reference_type;
595 bool isinitialized () const
597 return (key == reference_type
599 || key == unresolved_reference_type);
602 bool isresolved () const
604 return (key == reference_type
606 || key == uninitialized_reference_type);
609 void verify_dimensions (int ndims, _Jv_BytecodeVerifier *verifier)
611 // The way this is written, we don't need to check isarray().
612 if (key == reference_type)
614 jclass k = data.klass;
615 while (k->isArray () && ndims > 0)
617 k = k->getComponentType ();
623 // We know KEY == unresolved_reference_type.
624 char *p = data.name->data;
625 while (*p++ == '[' && ndims-- > 0)
630 verifier->verify_fail ("array type has fewer dimensions than required");
633 // Merge OLD_TYPE into this. On error throw exception.
634 bool merge (type& old_type, bool local_semantics,
635 _Jv_BytecodeVerifier *verifier)
637 bool changed = false;
638 bool refo = old_type.isreference ();
639 bool refn = isreference ();
642 if (old_type.key == null_type)
644 else if (key == null_type)
649 else if (isinitialized () != old_type.isinitialized ())
650 verifier->verify_fail ("merging initialized and uninitialized types");
653 if (! isinitialized ())
657 else if (old_type.pc == UNINIT)
659 else if (pc != old_type.pc)
660 verifier->verify_fail ("merging different uninitialized types");
664 && ! old_type.isresolved ()
665 && _Jv_equalUtf8Consts (data.name, old_type.data.name))
667 // Types are identical.
672 old_type.resolve (verifier);
674 jclass k = data.klass;
675 jclass oldk = old_type.data.klass;
678 while (k->isArray () && oldk->isArray ())
681 k = k->getComponentType ();
682 oldk = oldk->getComponentType ();
685 // Ordinarily this terminates when we hit Object...
688 if (is_assignable_from_slow (k, oldk))
690 k = k->getSuperclass ();
693 // ... but K could have been an interface, in which
694 // case we'll end up here. We just convert this
697 k = &java::lang::Object::class$;
701 while (arraycount > 0)
703 java::lang::ClassLoader *loader
704 = verifier->current_class->getClassLoader();
705 k = _Jv_GetArrayClass (k, loader);
713 else if (refo || refn || key != old_type.key)
717 // If we're merging into an "unused" slot, then we
718 // simply accept whatever we're merging from.
719 if (key == unused_by_subroutine_type)
724 else if (old_type.key == unused_by_subroutine_type)
728 // If we already have an `unsuitable' type, then we
729 // don't need to change again.
730 else if (key != unsuitable_type)
732 key = unsuitable_type;
737 verifier->verify_fail ("unmergeable type");
743 void print (void) const
748 case boolean_type: c = 'Z'; break;
749 case byte_type: c = 'B'; break;
750 case char_type: c = 'C'; break;
751 case short_type: c = 'S'; break;
752 case int_type: c = 'I'; break;
753 case long_type: c = 'J'; break;
754 case float_type: c = 'F'; break;
755 case double_type: c = 'D'; break;
756 case void_type: c = 'V'; break;
757 case unsuitable_type: c = '-'; break;
758 case return_address_type: c = 'r'; break;
759 case continuation_type: c = '+'; break;
760 case unused_by_subroutine_type: c = '_'; break;
761 case reference_type: c = 'L'; break;
762 case null_type: c = '@'; break;
763 case unresolved_reference_type: c = 'l'; break;
764 case uninitialized_reference_type: c = 'U'; break;
765 case uninitialized_unresolved_reference_type: c = 'u'; break;
767 debug_print ("%c", c);
769 #endif /* VERIFY_DEBUG */
772 // This class holds all the state information we need for a given
776 // Current top of stack.
778 // Current stack depth. This is like the top of stack but it
779 // includes wide variable information.
783 // The local variables.
785 // This is used in subroutines to keep track of which local
786 // variables have been accessed.
788 // If not 0, then we are in a subroutine. The value is the PC of
789 // the subroutine's entry point. We can use 0 as an exceptional
790 // value because PC=0 can never be a subroutine.
792 // This is used to keep a linked list of all the states which
793 // require re-verification. We use the PC to keep track.
795 // We keep track of the type of `this' specially. This is used to
796 // ensure that an instance initializer invokes another initializer
797 // on `this' before returning. We must keep track of this
798 // specially because otherwise we might be confused by code which
799 // assigns to locals[0] (overwriting `this') and then returns
800 // without really initializing.
803 // INVALID marks a state which is not on the linked list of states
804 // requiring reverification.
805 static const int INVALID = -1;
806 // NO_NEXT marks the state at the end of the reverification list.
807 static const int NO_NEXT = -2;
814 local_changed = NULL;
817 state (int max_stack, int max_locals)
822 stack = new type[max_stack];
823 for (int i = 0; i < max_stack; ++i)
824 stack[i] = unsuitable_type;
825 locals = new type[max_locals];
826 local_changed = (bool *) _Jv_Malloc (sizeof (bool) * max_locals);
827 for (int i = 0; i < max_locals; ++i)
829 locals[i] = unsuitable_type;
830 local_changed[i] = false;
836 state (const state *orig, int max_stack, int max_locals,
837 bool ret_semantics = false)
839 stack = new type[max_stack];
840 locals = new type[max_locals];
841 local_changed = (bool *) _Jv_Malloc (sizeof (bool) * max_locals);
842 copy (orig, max_stack, max_locals, ret_semantics);
853 _Jv_Free (local_changed);
856 void *operator new[] (size_t bytes)
858 return _Jv_Malloc (bytes);
861 void operator delete[] (void *mem)
866 void *operator new (size_t bytes)
868 return _Jv_Malloc (bytes);
871 void operator delete (void *mem)
876 void copy (const state *copy, int max_stack, int max_locals,
877 bool ret_semantics = false)
879 stacktop = copy->stacktop;
880 stackdepth = copy->stackdepth;
881 subroutine = copy->subroutine;
882 for (int i = 0; i < max_stack; ++i)
883 stack[i] = copy->stack[i];
884 for (int i = 0; i < max_locals; ++i)
886 // See push_jump_merge to understand this case.
888 locals[i] = type (copy->local_changed[i]
890 : unused_by_subroutine_type);
892 locals[i] = copy->locals[i];
893 local_changed[i] = copy->local_changed[i];
895 this_type = copy->this_type;
896 // Don't modify `next'.
899 // Modify this state to reflect entry to an exception handler.
900 void set_exception (type t, int max_stack)
905 for (int i = stacktop; i < max_stack; ++i)
906 stack[i] = unsuitable_type;
909 // Modify this state to reflect entry into a subroutine.
910 void enter_subroutine (int npc, int max_locals)
913 // Mark all items as unchanged. Each subroutine needs to keep
914 // track of its `changed' state independently. In the case of
915 // nested subroutines, this information will be merged back into
916 // parent by the `ret'.
917 for (int i = 0; i < max_locals; ++i)
918 local_changed[i] = false;
921 // Merge STATE_OLD into this state. Destructively modifies this
922 // state. Returns true if the new state was in fact changed.
923 // Will throw an exception if the states are not mergeable.
924 bool merge (state *state_old, bool ret_semantics,
925 int max_locals, _Jv_BytecodeVerifier *verifier)
927 bool changed = false;
929 // Special handling for `this'. If one or the other is
930 // uninitialized, then the merge is uninitialized.
931 if (this_type.isinitialized ())
932 this_type = state_old->this_type;
934 // Merge subroutine states. Here we just keep track of what
935 // subroutine we think we're in. We only check for a merge
936 // (which is invalid) when we see a `ret'.
937 if (subroutine == state_old->subroutine)
941 else if (subroutine == 0)
943 subroutine = state_old->subroutine;
948 // If the subroutines differ, indicate that the state
949 // changed. This is needed to detect when subroutines have
955 if (state_old->stacktop != stacktop)
956 verifier->verify_fail ("stack sizes differ");
957 for (int i = 0; i < state_old->stacktop; ++i)
959 if (stack[i].merge (state_old->stack[i], false, verifier))
963 // Merge local variables.
964 for (int i = 0; i < max_locals; ++i)
966 // If we're not processing a `ret', then we merge every
967 // local variable. If we are processing a `ret', then we
968 // only merge locals which changed in the subroutine. When
969 // processing a `ret', STATE_OLD is the state at the point
970 // of the `ret', and THIS is the state just after the `jsr'.
971 if (! ret_semantics || state_old->local_changed[i])
973 if (locals[i].merge (state_old->locals[i], true, verifier))
975 // Note that we don't call `note_variable' here.
976 // This change doesn't represent a real change to a
977 // local, but rather a merge artifact. If we're in
978 // a subroutine which is called with two
979 // incompatible types in a slot that is unused by
980 // the subroutine, then we don't want to mark that
981 // variable as having been modified.
986 // If we're in a subroutine, we must compute the union of
987 // all the changed local variables.
988 if (state_old->local_changed[i])
995 // Throw an exception if there is an uninitialized object on the
996 // stack or in a local variable. EXCEPTION_SEMANTICS controls
997 // whether we're using backwards-branch or exception-handing
999 void check_no_uninitialized_objects (int max_locals,
1000 _Jv_BytecodeVerifier *verifier,
1001 bool exception_semantics = false)
1003 if (! exception_semantics)
1005 for (int i = 0; i < stacktop; ++i)
1006 if (stack[i].isreference () && ! stack[i].isinitialized ())
1007 verifier->verify_fail ("uninitialized object on stack");
1010 for (int i = 0; i < max_locals; ++i)
1011 if (locals[i].isreference () && ! locals[i].isinitialized ())
1012 verifier->verify_fail ("uninitialized object in local variable");
1014 check_this_initialized (verifier);
1017 // Ensure that `this' has been initialized.
1018 void check_this_initialized (_Jv_BytecodeVerifier *verifier)
1020 if (this_type.isreference () && ! this_type.isinitialized ())
1021 verifier->verify_fail ("`this' is uninitialized");
1024 // Set type of `this'.
1025 void set_this_type (const type &k)
1030 // Note that a local variable was modified.
1031 void note_variable (int index)
1034 local_changed[index] = true;
1037 // Mark each `new'd object we know of that was allocated at PC as
1039 void set_initialized (int pc, int max_locals)
1041 for (int i = 0; i < stacktop; ++i)
1042 stack[i].set_initialized (pc);
1043 for (int i = 0; i < max_locals; ++i)
1044 locals[i].set_initialized (pc);
1045 this_type.set_initialized (pc);
1048 // Return true if this state is the unmerged result of a `ret'.
1049 bool is_unmerged_ret_state (int max_locals) const
1051 for (int i = 0; i < max_locals; ++i)
1053 if (locals[i].key == unused_by_subroutine_type)
1060 void print (const char *leader, int pc,
1061 int max_stack, int max_locals) const
1063 debug_print ("%s [%4d]: [stack] ", leader, pc);
1065 for (i = 0; i < stacktop; ++i)
1067 for (; i < max_stack; ++i)
1069 debug_print (" [local] ");
1070 for (i = 0; i < max_locals; ++i)
1073 debug_print (local_changed[i] ? "+" : " ");
1075 if (subroutine == 0)
1076 debug_print (" | None");
1078 debug_print (" | %4d", subroutine);
1079 debug_print (" | %p\n", this);
1082 inline void print (const char *, int, int, int) const
1085 #endif /* VERIFY_DEBUG */
1090 if (current_state->stacktop <= 0)
1091 verify_fail ("stack empty");
1092 type r = current_state->stack[--current_state->stacktop];
1093 current_state->stackdepth -= r.depth ();
1094 if (current_state->stackdepth < 0)
1095 verify_fail ("stack empty", start_PC);
1101 type r = pop_raw ();
1103 verify_fail ("narrow pop of wide type");
1109 type r = pop_raw ();
1111 verify_fail ("wide pop of narrow type");
1115 type pop_type (type match)
1118 type t = pop_raw ();
1119 if (! match.compatible (t, this))
1120 verify_fail ("incompatible type on stack");
1124 // Pop a reference type or a return address.
1125 type pop_ref_or_return ()
1127 type t = pop_raw ();
1128 if (! t.isreference () && t.key != return_address_type)
1129 verify_fail ("expected reference or return address on stack");
1133 void push_type (type t)
1135 // If T is a numeric type like short, promote it to int.
1138 int depth = t.depth ();
1139 if (current_state->stackdepth + depth > current_method->max_stack)
1140 verify_fail ("stack overflow");
1141 current_state->stack[current_state->stacktop++] = t;
1142 current_state->stackdepth += depth;
1145 void set_variable (int index, type t)
1147 // If T is a numeric type like short, promote it to int.
1150 int depth = t.depth ();
1151 if (index > current_method->max_locals - depth)
1152 verify_fail ("invalid local variable");
1153 current_state->locals[index] = t;
1154 current_state->note_variable (index);
1158 current_state->locals[index + 1] = continuation_type;
1159 current_state->note_variable (index + 1);
1161 if (index > 0 && current_state->locals[index - 1].iswide ())
1163 current_state->locals[index - 1] = unsuitable_type;
1164 // There's no need to call note_variable here.
1168 type get_variable (int index, type t)
1170 int depth = t.depth ();
1171 if (index > current_method->max_locals - depth)
1172 verify_fail ("invalid local variable");
1173 if (! t.compatible (current_state->locals[index], this))
1174 verify_fail ("incompatible type in local variable");
1177 type t (continuation_type);
1178 if (! current_state->locals[index + 1].compatible (t, this))
1179 verify_fail ("invalid local variable");
1181 return current_state->locals[index];
1184 // Make sure ARRAY is an array type and that its elements are
1185 // compatible with type ELEMENT. Returns the actual element type.
1186 type require_array_type (type array, type element)
1188 // An odd case. Here we just pretend that everything went ok. If
1189 // the requested element type is some kind of reference, return
1190 // the null type instead.
1191 if (array.isnull ())
1192 return element.isreference () ? type (null_type) : element;
1194 if (! array.isarray ())
1195 verify_fail ("array required");
1197 type t = array.element_type (this);
1198 if (! element.compatible (t, this))
1200 // Special case for byte arrays, which must also be boolean
1203 if (element.key == byte_type)
1205 type e2 (boolean_type);
1206 ok = e2.compatible (t, this);
1209 verify_fail ("incompatible array element type");
1212 // Return T and not ELEMENT, because T might be specialized.
1218 if (PC >= current_method->code_length)
1219 verify_fail ("premature end of bytecode");
1220 return (jint) bytecode[PC++] & 0xff;
1225 jint b1 = get_byte ();
1226 jint b2 = get_byte ();
1227 return (jint) ((b1 << 8) | b2) & 0xffff;
1232 jint b1 = get_byte ();
1233 jint b2 = get_byte ();
1234 jshort s = (b1 << 8) | b2;
1240 jint b1 = get_byte ();
1241 jint b2 = get_byte ();
1242 jint b3 = get_byte ();
1243 jint b4 = get_byte ();
1244 return (b1 << 24) | (b2 << 16) | (b3 << 8) | b4;
1247 int compute_jump (int offset)
1249 int npc = start_PC + offset;
1250 if (npc < 0 || npc >= current_method->code_length)
1251 verify_fail ("branch out of range", start_PC);
1255 // Merge the indicated state into the state at the branch target and
1256 // schedule a new PC if there is a change. If RET_SEMANTICS is
1257 // true, then we are merging from a `ret' instruction into the
1258 // instruction after a `jsr'. This is a special case with its own
1259 // modified semantics.
1260 void push_jump_merge (int npc, state *nstate, bool ret_semantics = false)
1262 bool changed = true;
1263 if (states[npc] == NULL)
1265 // There's a weird situation here. If are examining the
1266 // branch that results from a `ret', and there is not yet a
1267 // state available at the branch target (the instruction just
1268 // after the `jsr'), then we have to construct a special kind
1269 // of state at that point for future merging. This special
1270 // state has the type `unused_by_subroutine_type' in each slot
1271 // which was not modified by the subroutine.
1272 states[npc] = new state (nstate, current_method->max_stack,
1273 current_method->max_locals, ret_semantics);
1274 debug_print ("== New state in push_jump_merge\n");
1275 states[npc]->print ("New", npc, current_method->max_stack,
1276 current_method->max_locals);
1280 debug_print ("== Merge states in push_jump_merge\n");
1281 nstate->print ("Frm", start_PC, current_method->max_stack,
1282 current_method->max_locals);
1283 states[npc]->print (" To", npc, current_method->max_stack,
1284 current_method->max_locals);
1285 changed = states[npc]->merge (nstate, ret_semantics,
1286 current_method->max_locals, this);
1287 states[npc]->print ("New", npc, current_method->max_stack,
1288 current_method->max_locals);
1291 if (changed && states[npc]->next == state::INVALID)
1293 // The merge changed the state, and the new PC isn't yet on our
1294 // list of PCs to re-verify.
1295 states[npc]->next = next_verify_pc;
1296 next_verify_pc = npc;
1300 void push_jump (int offset)
1302 int npc = compute_jump (offset);
1304 current_state->check_no_uninitialized_objects (current_method->max_locals, this);
1305 push_jump_merge (npc, current_state);
1308 void push_exception_jump (type t, int pc)
1310 current_state->check_no_uninitialized_objects (current_method->max_locals,
1312 state s (current_state, current_method->max_stack,
1313 current_method->max_locals);
1314 if (current_method->max_stack < 1)
1315 verify_fail ("stack overflow at exception handler");
1316 s.set_exception (t, current_method->max_stack);
1317 push_jump_merge (pc, &s);
1322 int *prev_loc = &next_verify_pc;
1323 int npc = next_verify_pc;
1324 bool skipped = false;
1326 while (npc != state::NO_NEXT)
1328 // If the next available PC is an unmerged `ret' state, then
1329 // we aren't yet ready to handle it. That's because we would
1330 // need all kind of special cases to do so. So instead we
1331 // defer this jump until after we've processed it via a
1332 // fall-through. This has to happen because the instruction
1333 // before this one must be a `jsr'.
1334 if (! states[npc]->is_unmerged_ret_state (current_method->max_locals))
1336 *prev_loc = states[npc]->next;
1337 states[npc]->next = state::INVALID;
1342 prev_loc = &states[npc]->next;
1343 npc = states[npc]->next;
1346 // If we've skipped states and there is nothing else, that's a
1349 verify_fail ("pop_jump: can't happen");
1350 return state::NO_NEXT;
1353 void invalidate_pc ()
1355 PC = state::NO_NEXT;
1358 void note_branch_target (int pc, bool is_jsr_target = false)
1360 // Don't check `pc <= PC', because we've advanced PC after
1361 // fetching the target and we haven't yet checked the next
1363 if (pc < PC && ! (flags[pc] & FLAG_INSN_START))
1364 verify_fail ("branch not to instruction start", start_PC);
1365 flags[pc] |= FLAG_BRANCH_TARGET;
1368 // Record the jsr which called this instruction.
1369 subr_info *info = (subr_info *) _Jv_Malloc (sizeof (subr_info));
1371 info->next = jsr_ptrs[pc];
1372 jsr_ptrs[pc] = info;
1376 void skip_padding ()
1378 while ((PC % 4) > 0)
1379 if (get_byte () != 0)
1380 verify_fail ("found nonzero padding byte");
1383 // Return the subroutine to which the instruction at PC belongs.
1384 int get_subroutine (int pc)
1386 if (states[pc] == NULL)
1388 return states[pc]->subroutine;
1391 // Do the work for a `ret' instruction. INDEX is the index into the
1393 void handle_ret_insn (int index)
1395 get_variable (index, return_address_type);
1397 int csub = current_state->subroutine;
1399 verify_fail ("no subroutine");
1401 // Check to see if we've merged subroutines.
1402 subr_entry_info *entry;
1403 for (entry = entry_points; entry != NULL; entry = entry->next)
1405 if (entry->ret_pc == start_PC)
1410 entry = (subr_entry_info *) _Jv_Malloc (sizeof (subr_entry_info));
1412 entry->ret_pc = start_PC;
1413 entry->next = entry_points;
1414 entry_points = entry;
1416 else if (entry->pc != csub)
1417 verify_fail ("subroutines merged");
1419 for (subr_info *subr = jsr_ptrs[csub]; subr != NULL; subr = subr->next)
1421 // Temporarily modify the current state so it looks like we're
1422 // in the enclosing context.
1423 current_state->subroutine = get_subroutine (subr->pc);
1425 current_state->check_no_uninitialized_objects (current_method->max_locals, this);
1426 push_jump_merge (subr->pc, current_state, true);
1429 current_state->subroutine = csub;
1433 // We're in the subroutine SUB, calling a subroutine at DEST. Make
1434 // sure this subroutine isn't already on the stack.
1435 void check_nonrecursive_call (int sub, int dest)
1440 verify_fail ("recursive subroutine call");
1441 for (subr_info *info = jsr_ptrs[sub]; info != NULL; info = info->next)
1442 check_nonrecursive_call (get_subroutine (info->pc), dest);
1445 void handle_jsr_insn (int offset)
1447 int npc = compute_jump (offset);
1450 current_state->check_no_uninitialized_objects (current_method->max_locals, this);
1451 check_nonrecursive_call (current_state->subroutine, npc);
1453 // Create a new state and modify it as appropriate for entry into
1454 // a subroutine. We're writing this in a weird way because,
1455 // unfortunately, push_type only works on the current state.
1456 push_type (return_address_type);
1457 push_jump_merge (npc, current_state);
1458 // Clean up the weirdness.
1459 pop_type (return_address_type);
1461 // On entry to the subroutine, the subroutine number must be set
1462 // and the locals must be marked as cleared. We do this after
1463 // merging state so that we don't erroneously "notice" a variable
1464 // change merely on entry.
1465 states[npc]->enter_subroutine (npc, current_method->max_locals);
1468 jclass construct_primitive_array_type (type_val prim)
1474 k = JvPrimClass (boolean);
1477 k = JvPrimClass (char);
1480 k = JvPrimClass (float);
1483 k = JvPrimClass (double);
1486 k = JvPrimClass (byte);
1489 k = JvPrimClass (short);
1492 k = JvPrimClass (int);
1495 k = JvPrimClass (long);
1498 verify_fail ("unknown type in construct_primitive_array_type");
1500 k = _Jv_GetArrayClass (k, NULL);
1504 // This pass computes the location of branch targets and also
1505 // instruction starts.
1506 void branch_prepass ()
1508 flags = (char *) _Jv_Malloc (current_method->code_length);
1509 jsr_ptrs = (subr_info **) _Jv_Malloc (sizeof (subr_info *)
1510 * current_method->code_length);
1512 for (int i = 0; i < current_method->code_length; ++i)
1518 bool last_was_jsr = false;
1521 while (PC < current_method->code_length)
1523 // Set `start_PC' early so that error checking can have the
1526 flags[PC] |= FLAG_INSN_START;
1528 // If the previous instruction was a jsr, then the next
1529 // instruction is a branch target -- the branch being the
1530 // corresponding `ret'.
1532 note_branch_target (PC);
1533 last_was_jsr = false;
1535 java_opcode opcode = (java_opcode) bytecode[PC++];
1539 case op_aconst_null:
1675 case op_monitorenter:
1676 case op_monitorexit:
1684 case op_arraylength:
1716 case op_invokespecial:
1717 case op_invokestatic:
1718 case op_invokevirtual:
1722 case op_multianewarray:
1728 last_was_jsr = true;
1747 note_branch_target (compute_jump (get_short ()), last_was_jsr);
1750 case op_tableswitch:
1753 note_branch_target (compute_jump (get_int ()));
1754 jint low = get_int ();
1755 jint hi = get_int ();
1757 verify_fail ("invalid tableswitch", start_PC);
1758 for (int i = low; i <= hi; ++i)
1759 note_branch_target (compute_jump (get_int ()));
1763 case op_lookupswitch:
1766 note_branch_target (compute_jump (get_int ()));
1767 int npairs = get_int ();
1769 verify_fail ("too few pairs in lookupswitch", start_PC);
1770 while (npairs-- > 0)
1773 note_branch_target (compute_jump (get_int ()));
1778 case op_invokeinterface:
1786 opcode = (java_opcode) get_byte ();
1788 if (opcode == op_iinc)
1794 last_was_jsr = true;
1797 note_branch_target (compute_jump (get_int ()), last_was_jsr);
1801 verify_fail ("unrecognized instruction in branch_prepass",
1805 // See if any previous branch tried to branch to the middle of
1806 // this instruction.
1807 for (int pc = start_PC + 1; pc < PC; ++pc)
1809 if ((flags[pc] & FLAG_BRANCH_TARGET))
1810 verify_fail ("branch to middle of instruction", pc);
1814 // Verify exception handlers.
1815 for (int i = 0; i < current_method->exc_count; ++i)
1817 if (! (flags[exception[i].handler_pc] & FLAG_INSN_START))
1818 verify_fail ("exception handler not at instruction start",
1819 exception[i].handler_pc);
1820 if (! (flags[exception[i].start_pc] & FLAG_INSN_START))
1821 verify_fail ("exception start not at instruction start",
1822 exception[i].start_pc);
1823 if (exception[i].end_pc != current_method->code_length
1824 && ! (flags[exception[i].end_pc] & FLAG_INSN_START))
1825 verify_fail ("exception end not at instruction start",
1826 exception[i].end_pc);
1828 flags[exception[i].handler_pc] |= FLAG_BRANCH_TARGET;
1832 void check_pool_index (int index)
1834 if (index < 0 || index >= current_class->constants.size)
1835 verify_fail ("constant pool index out of range", start_PC);
1838 type check_class_constant (int index)
1840 check_pool_index (index);
1841 _Jv_Constants *pool = ¤t_class->constants;
1842 if (pool->tags[index] == JV_CONSTANT_ResolvedClass)
1843 return type (pool->data[index].clazz);
1844 else if (pool->tags[index] == JV_CONSTANT_Class)
1845 return type (pool->data[index].utf8);
1846 verify_fail ("expected class constant", start_PC);
1849 type check_constant (int index)
1851 check_pool_index (index);
1852 _Jv_Constants *pool = ¤t_class->constants;
1853 if (pool->tags[index] == JV_CONSTANT_ResolvedString
1854 || pool->tags[index] == JV_CONSTANT_String)
1855 return type (&java::lang::String::class$);
1856 else if (pool->tags[index] == JV_CONSTANT_Integer)
1857 return type (int_type);
1858 else if (pool->tags[index] == JV_CONSTANT_Float)
1859 return type (float_type);
1860 verify_fail ("String, int, or float constant expected", start_PC);
1863 type check_wide_constant (int index)
1865 check_pool_index (index);
1866 _Jv_Constants *pool = ¤t_class->constants;
1867 if (pool->tags[index] == JV_CONSTANT_Long)
1868 return type (long_type);
1869 else if (pool->tags[index] == JV_CONSTANT_Double)
1870 return type (double_type);
1871 verify_fail ("long or double constant expected", start_PC);
1874 // Helper for both field and method. These are laid out the same in
1875 // the constant pool.
1876 type handle_field_or_method (int index, int expected,
1877 _Jv_Utf8Const **name,
1878 _Jv_Utf8Const **fmtype)
1880 check_pool_index (index);
1881 _Jv_Constants *pool = ¤t_class->constants;
1882 if (pool->tags[index] != expected)
1883 verify_fail ("didn't see expected constant", start_PC);
1884 // Once we know we have a Fieldref or Methodref we assume that it
1885 // is correctly laid out in the constant pool. I think the code
1886 // in defineclass.cc guarantees this.
1887 _Jv_ushort class_index, name_and_type_index;
1888 _Jv_loadIndexes (&pool->data[index],
1890 name_and_type_index);
1891 _Jv_ushort name_index, desc_index;
1892 _Jv_loadIndexes (&pool->data[name_and_type_index],
1893 name_index, desc_index);
1895 *name = pool->data[name_index].utf8;
1896 *fmtype = pool->data[desc_index].utf8;
1898 return check_class_constant (class_index);
1901 // Return field's type, compute class' type if requested.
1902 type check_field_constant (int index, type *class_type = NULL)
1904 _Jv_Utf8Const *name, *field_type;
1905 type ct = handle_field_or_method (index,
1906 JV_CONSTANT_Fieldref,
1907 &name, &field_type);
1910 if (field_type->data[0] == '[' || field_type->data[0] == 'L')
1911 return type (field_type);
1912 return get_type_val_for_signature (field_type->data[0]);
1915 type check_method_constant (int index, bool is_interface,
1916 _Jv_Utf8Const **method_name,
1917 _Jv_Utf8Const **method_signature)
1919 return handle_field_or_method (index,
1921 ? JV_CONSTANT_InterfaceMethodref
1922 : JV_CONSTANT_Methodref),
1923 method_name, method_signature);
1926 type get_one_type (char *&p)
1944 _Jv_Utf8Const *name = make_utf8_const (start, p - start);
1948 // Casting to jchar here is ok since we are looking at an ASCII
1950 type_val rt = get_type_val_for_signature (jchar (v));
1952 if (arraycount == 0)
1954 // Callers of this function eventually push their arguments on
1955 // the stack. So, promote them here.
1956 return type (rt).promote ();
1959 jclass k = construct_primitive_array_type (rt);
1960 while (--arraycount > 0)
1961 k = _Jv_GetArrayClass (k, NULL);
1965 void compute_argument_types (_Jv_Utf8Const *signature,
1968 char *p = signature->data;
1974 types[i++] = get_one_type (p);
1977 type compute_return_type (_Jv_Utf8Const *signature)
1979 char *p = signature->data;
1983 return get_one_type (p);
1986 void check_return_type (type onstack)
1988 type rt = compute_return_type (current_method->self->signature);
1989 if (! rt.compatible (onstack, this))
1990 verify_fail ("incompatible return type");
1993 // Initialize the stack for the new method. Returns true if this
1994 // method is an instance initializer.
1995 bool initialize_stack ()
1998 bool is_init = false;
2000 using namespace java::lang::reflect;
2001 if (! Modifier::isStatic (current_method->self->accflags))
2003 type kurr (current_class);
2004 if (_Jv_equalUtf8Consts (current_method->self->name, gcj::init_name))
2006 kurr.set_uninitialized (type::SELF, this);
2009 set_variable (0, kurr);
2010 current_state->set_this_type (kurr);
2014 // We have to handle wide arguments specially here.
2015 int arg_count = _Jv_count_arguments (current_method->self->signature);
2016 type arg_types[arg_count];
2017 compute_argument_types (current_method->self->signature, arg_types);
2018 for (int i = 0; i < arg_count; ++i)
2020 set_variable (var, arg_types[i]);
2022 if (arg_types[i].iswide ())
2029 void verify_instructions_0 ()
2031 current_state = new state (current_method->max_stack,
2032 current_method->max_locals);
2037 // True if we are verifying an instance initializer.
2038 bool this_is_init = initialize_stack ();
2040 states = (state **) _Jv_Malloc (sizeof (state *)
2041 * current_method->code_length);
2042 for (int i = 0; i < current_method->code_length; ++i)
2045 next_verify_pc = state::NO_NEXT;
2049 // If the PC was invalidated, get a new one from the work list.
2050 if (PC == state::NO_NEXT)
2053 if (PC == state::INVALID)
2054 verify_fail ("can't happen: saw state::INVALID");
2055 if (PC == state::NO_NEXT)
2057 debug_print ("== State pop from pending list\n");
2058 // Set up the current state.
2059 current_state->copy (states[PC], current_method->max_stack,
2060 current_method->max_locals);
2064 // Control can't fall off the end of the bytecode. We
2065 // only need to check this in the fall-through case,
2066 // because branch bounds are checked when they are
2068 if (PC >= current_method->code_length)
2069 verify_fail ("fell off end");
2071 // We only have to do this checking in the situation where
2072 // control flow falls through from the previous
2073 // instruction. Otherwise merging is done at the time we
2075 if (states[PC] != NULL)
2077 // We've already visited this instruction. So merge
2078 // the states together. If this yields no change then
2079 // we don't have to re-verify. However, if the new
2080 // state is an the result of an unmerged `ret', we
2081 // must continue through it.
2082 debug_print ("== Fall through merge\n");
2083 states[PC]->print ("Old", PC, current_method->max_stack,
2084 current_method->max_locals);
2085 current_state->print ("Cur", PC, current_method->max_stack,
2086 current_method->max_locals);
2087 if (! current_state->merge (states[PC], false,
2088 current_method->max_locals, this)
2089 && ! states[PC]->is_unmerged_ret_state (current_method->max_locals))
2091 debug_print ("== Fall through optimization\n");
2095 // Save a copy of it for later.
2096 states[PC]->copy (current_state, current_method->max_stack,
2097 current_method->max_locals);
2098 current_state->print ("New", PC, current_method->max_stack,
2099 current_method->max_locals);
2103 // We only have to keep saved state at branch targets. If
2104 // we're at a branch target and the state here hasn't been set
2105 // yet, we set it now.
2106 if (states[PC] == NULL && (flags[PC] & FLAG_BRANCH_TARGET))
2108 states[PC] = new state (current_state, current_method->max_stack,
2109 current_method->max_locals);
2112 // Set this before handling exceptions so that debug output is
2116 // Update states for all active exception handlers. Ordinarily
2117 // there are not many exception handlers. So we simply run
2118 // through them all.
2119 for (int i = 0; i < current_method->exc_count; ++i)
2121 if (PC >= exception[i].start_pc && PC < exception[i].end_pc)
2123 type handler (&java::lang::Throwable::class$);
2124 if (exception[i].handler_type != 0)
2125 handler = check_class_constant (exception[i].handler_type);
2126 push_exception_jump (handler, exception[i].handler_pc);
2130 current_state->print (" ", PC, current_method->max_stack,
2131 current_method->max_locals);
2132 java_opcode opcode = (java_opcode) bytecode[PC++];
2138 case op_aconst_null:
2139 push_type (null_type);
2149 push_type (int_type);
2154 push_type (long_type);
2160 push_type (float_type);
2165 push_type (double_type);
2170 push_type (int_type);
2175 push_type (int_type);
2179 push_type (check_constant (get_byte ()));
2182 push_type (check_constant (get_ushort ()));
2185 push_type (check_wide_constant (get_ushort ()));
2189 push_type (get_variable (get_byte (), int_type));
2192 push_type (get_variable (get_byte (), long_type));
2195 push_type (get_variable (get_byte (), float_type));
2198 push_type (get_variable (get_byte (), double_type));
2201 push_type (get_variable (get_byte (), reference_type));
2208 push_type (get_variable (opcode - op_iload_0, int_type));
2214 push_type (get_variable (opcode - op_lload_0, long_type));
2220 push_type (get_variable (opcode - op_fload_0, float_type));
2226 push_type (get_variable (opcode - op_dload_0, double_type));
2232 push_type (get_variable (opcode - op_aload_0, reference_type));
2235 pop_type (int_type);
2236 push_type (require_array_type (pop_type (reference_type),
2240 pop_type (int_type);
2241 push_type (require_array_type (pop_type (reference_type),
2245 pop_type (int_type);
2246 push_type (require_array_type (pop_type (reference_type),
2250 pop_type (int_type);
2251 push_type (require_array_type (pop_type (reference_type),
2255 pop_type (int_type);
2256 push_type (require_array_type (pop_type (reference_type),
2260 pop_type (int_type);
2261 require_array_type (pop_type (reference_type), byte_type);
2262 push_type (int_type);
2265 pop_type (int_type);
2266 require_array_type (pop_type (reference_type), char_type);
2267 push_type (int_type);
2270 pop_type (int_type);
2271 require_array_type (pop_type (reference_type), short_type);
2272 push_type (int_type);
2275 set_variable (get_byte (), pop_type (int_type));
2278 set_variable (get_byte (), pop_type (long_type));
2281 set_variable (get_byte (), pop_type (float_type));
2284 set_variable (get_byte (), pop_type (double_type));
2287 set_variable (get_byte (), pop_ref_or_return ());
2293 set_variable (opcode - op_istore_0, pop_type (int_type));
2299 set_variable (opcode - op_lstore_0, pop_type (long_type));
2305 set_variable (opcode - op_fstore_0, pop_type (float_type));
2311 set_variable (opcode - op_dstore_0, pop_type (double_type));
2317 set_variable (opcode - op_astore_0, pop_ref_or_return ());
2320 pop_type (int_type);
2321 pop_type (int_type);
2322 require_array_type (pop_type (reference_type), int_type);
2325 pop_type (long_type);
2326 pop_type (int_type);
2327 require_array_type (pop_type (reference_type), long_type);
2330 pop_type (float_type);
2331 pop_type (int_type);
2332 require_array_type (pop_type (reference_type), float_type);
2335 pop_type (double_type);
2336 pop_type (int_type);
2337 require_array_type (pop_type (reference_type), double_type);
2340 pop_type (reference_type);
2341 pop_type (int_type);
2342 require_array_type (pop_type (reference_type), reference_type);
2345 pop_type (int_type);
2346 pop_type (int_type);
2347 require_array_type (pop_type (reference_type), byte_type);
2350 pop_type (int_type);
2351 pop_type (int_type);
2352 require_array_type (pop_type (reference_type), char_type);
2355 pop_type (int_type);
2356 pop_type (int_type);
2357 require_array_type (pop_type (reference_type), short_type);
2384 type t2 = pop_raw ();
2399 type t = pop_raw ();
2414 type t1 = pop_raw ();
2431 type t1 = pop_raw ();
2434 type t2 = pop_raw ();
2452 type t3 = pop_raw ();
2490 pop_type (int_type);
2491 push_type (pop_type (int_type));
2501 pop_type (long_type);
2502 push_type (pop_type (long_type));
2507 pop_type (int_type);
2508 push_type (pop_type (long_type));
2515 pop_type (float_type);
2516 push_type (pop_type (float_type));
2523 pop_type (double_type);
2524 push_type (pop_type (double_type));
2530 push_type (pop_type (int_type));
2533 push_type (pop_type (long_type));
2536 push_type (pop_type (float_type));
2539 push_type (pop_type (double_type));
2542 get_variable (get_byte (), int_type);
2546 pop_type (int_type);
2547 push_type (long_type);
2550 pop_type (int_type);
2551 push_type (float_type);
2554 pop_type (int_type);
2555 push_type (double_type);
2558 pop_type (long_type);
2559 push_type (int_type);
2562 pop_type (long_type);
2563 push_type (float_type);
2566 pop_type (long_type);
2567 push_type (double_type);
2570 pop_type (float_type);
2571 push_type (int_type);
2574 pop_type (float_type);
2575 push_type (long_type);
2578 pop_type (float_type);
2579 push_type (double_type);
2582 pop_type (double_type);
2583 push_type (int_type);
2586 pop_type (double_type);
2587 push_type (long_type);
2590 pop_type (double_type);
2591 push_type (float_type);
2594 pop_type (long_type);
2595 pop_type (long_type);
2596 push_type (int_type);
2600 pop_type (float_type);
2601 pop_type (float_type);
2602 push_type (int_type);
2606 pop_type (double_type);
2607 pop_type (double_type);
2608 push_type (int_type);
2616 pop_type (int_type);
2617 push_jump (get_short ());
2625 pop_type (int_type);
2626 pop_type (int_type);
2627 push_jump (get_short ());
2631 pop_type (reference_type);
2632 pop_type (reference_type);
2633 push_jump (get_short ());
2636 push_jump (get_short ());
2640 handle_jsr_insn (get_short ());
2643 handle_ret_insn (get_byte ());
2645 case op_tableswitch:
2647 pop_type (int_type);
2649 push_jump (get_int ());
2650 jint low = get_int ();
2651 jint high = get_int ();
2652 // Already checked LOW -vs- HIGH.
2653 for (int i = low; i <= high; ++i)
2654 push_jump (get_int ());
2659 case op_lookupswitch:
2661 pop_type (int_type);
2663 push_jump (get_int ());
2664 jint npairs = get_int ();
2665 // Already checked NPAIRS >= 0.
2667 for (int i = 0; i < npairs; ++i)
2669 jint key = get_int ();
2670 if (i > 0 && key <= lastkey)
2671 verify_fail ("lookupswitch pairs unsorted", start_PC);
2673 push_jump (get_int ());
2679 check_return_type (pop_type (int_type));
2683 check_return_type (pop_type (long_type));
2687 check_return_type (pop_type (float_type));
2691 check_return_type (pop_type (double_type));
2695 check_return_type (pop_type (reference_type));
2699 // We only need to check this when the return type is
2700 // void, because all instance initializers return void.
2702 current_state->check_this_initialized (this);
2703 check_return_type (void_type);
2707 push_type (check_field_constant (get_ushort ()));
2710 pop_type (check_field_constant (get_ushort ()));
2715 type field = check_field_constant (get_ushort (), &klass);
2723 type field = check_field_constant (get_ushort (), &klass);
2726 // We have an obscure special case here: we can use
2727 // `putfield' on a field declared in this class, even if
2728 // `this' has not yet been initialized.
2729 if (! current_state->this_type.isinitialized ()
2730 && current_state->this_type.pc == type::SELF)
2731 klass.set_uninitialized (type::SELF, this);
2736 case op_invokevirtual:
2737 case op_invokespecial:
2738 case op_invokestatic:
2739 case op_invokeinterface:
2741 _Jv_Utf8Const *method_name, *method_signature;
2743 = check_method_constant (get_ushort (),
2744 opcode == op_invokeinterface,
2747 // NARGS is only used when we're processing
2748 // invokeinterface. It is simplest for us to compute it
2749 // here and then verify it later.
2751 if (opcode == op_invokeinterface)
2753 nargs = get_byte ();
2754 if (get_byte () != 0)
2755 verify_fail ("invokeinterface dummy byte is wrong");
2758 bool is_init = false;
2759 if (_Jv_equalUtf8Consts (method_name, gcj::init_name))
2762 if (opcode != op_invokespecial)
2763 verify_fail ("can't invoke <init>");
2765 else if (method_name->data[0] == '<')
2766 verify_fail ("can't invoke method starting with `<'");
2768 // Pop arguments and check types.
2769 int arg_count = _Jv_count_arguments (method_signature);
2770 type arg_types[arg_count];
2771 compute_argument_types (method_signature, arg_types);
2772 for (int i = arg_count - 1; i >= 0; --i)
2774 // This is only used for verifying the byte for
2776 nargs -= arg_types[i].depth ();
2777 pop_type (arg_types[i]);
2780 if (opcode == op_invokeinterface
2782 verify_fail ("wrong argument count for invokeinterface");
2784 if (opcode != op_invokestatic)
2786 type t = class_type;
2789 // In this case the PC doesn't matter.
2790 t.set_uninitialized (type::UNINIT, this);
2792 type raw = pop_raw ();
2794 if (t.compatible (raw, this))
2798 else if (opcode == op_invokeinterface)
2800 // This is a hack. We might have merged two
2801 // items and gotten `Object'. This can happen
2802 // because we don't keep track of where merges
2803 // come from. This is safe as long as the
2804 // interpreter checks interfaces at runtime.
2805 type obj (&java::lang::Object::class$);
2806 ok = raw.compatible (obj, this);
2810 verify_fail ("incompatible type on stack");
2813 current_state->set_initialized (raw.get_pc (),
2814 current_method->max_locals);
2817 type rt = compute_return_type (method_signature);
2825 type t = check_class_constant (get_ushort ());
2826 if (t.isarray () || t.isinterface (this) || t.isabstract (this))
2827 verify_fail ("type is array, interface, or abstract");
2828 t.set_uninitialized (start_PC, this);
2835 int atype = get_byte ();
2836 // We intentionally have chosen constants to make this
2838 if (atype < boolean_type || atype > long_type)
2839 verify_fail ("type not primitive", start_PC);
2840 pop_type (int_type);
2841 push_type (construct_primitive_array_type (type_val (atype)));
2845 pop_type (int_type);
2846 push_type (check_class_constant (get_ushort ()).to_array (this));
2848 case op_arraylength:
2850 type t = pop_type (reference_type);
2851 if (! t.isarray () && ! t.isnull ())
2852 verify_fail ("array type expected");
2853 push_type (int_type);
2857 pop_type (type (&java::lang::Throwable::class$));
2861 pop_type (reference_type);
2862 push_type (check_class_constant (get_ushort ()));
2865 pop_type (reference_type);
2866 check_class_constant (get_ushort ());
2867 push_type (int_type);
2869 case op_monitorenter:
2870 pop_type (reference_type);
2872 case op_monitorexit:
2873 pop_type (reference_type);
2877 switch (get_byte ())
2880 push_type (get_variable (get_ushort (), int_type));
2883 push_type (get_variable (get_ushort (), long_type));
2886 push_type (get_variable (get_ushort (), float_type));
2889 push_type (get_variable (get_ushort (), double_type));
2892 push_type (get_variable (get_ushort (), reference_type));
2895 set_variable (get_ushort (), pop_type (int_type));
2898 set_variable (get_ushort (), pop_type (long_type));
2901 set_variable (get_ushort (), pop_type (float_type));
2904 set_variable (get_ushort (), pop_type (double_type));
2907 set_variable (get_ushort (), pop_type (reference_type));
2910 handle_ret_insn (get_short ());
2913 get_variable (get_ushort (), int_type);
2917 verify_fail ("unrecognized wide instruction", start_PC);
2921 case op_multianewarray:
2923 type atype = check_class_constant (get_ushort ());
2924 int dim = get_byte ();
2926 verify_fail ("too few dimensions to multianewarray", start_PC);
2927 atype.verify_dimensions (dim, this);
2928 for (int i = 0; i < dim; ++i)
2929 pop_type (int_type);
2935 pop_type (reference_type);
2936 push_jump (get_short ());
2939 push_jump (get_int ());
2943 handle_jsr_insn (get_int ());
2947 // Unrecognized opcode.
2948 verify_fail ("unrecognized instruction in verify_instructions_0",
2954 __attribute__ ((__noreturn__)) void verify_fail (char *s, jint pc = -1)
2956 using namespace java::lang;
2957 StringBuffer *buf = new StringBuffer ();
2959 buf->append (JvNewStringLatin1 ("verification failed"));
2964 buf->append (JvNewStringLatin1 (" at PC "));
2968 _Jv_InterpMethod *method = current_method;
2969 buf->append (JvNewStringLatin1 (" in "));
2970 buf->append (current_class->getName());
2971 buf->append ((jchar) ':');
2972 buf->append (JvNewStringUTF (method->get_method()->name->data));
2973 buf->append ((jchar) '(');
2974 buf->append (JvNewStringUTF (method->get_method()->signature->data));
2975 buf->append ((jchar) ')');
2977 buf->append (JvNewStringLatin1 (": "));
2978 buf->append (JvNewStringLatin1 (s));
2979 throw new java::lang::VerifyError (buf->toString ());
2984 void verify_instructions ()
2987 verify_instructions_0 ();
2990 _Jv_BytecodeVerifier (_Jv_InterpMethod *m)
2992 // We just print the text as utf-8. This is just for debugging
2994 debug_print ("--------------------------------\n");
2995 debug_print ("-- Verifying method `%s'\n", m->self->name->data);
2998 bytecode = m->bytecode ();
2999 exception = m->exceptions ();
3000 current_class = m->defining_class;
3006 entry_points = NULL;
3009 ~_Jv_BytecodeVerifier ()
3018 for (int i = 0; i < current_method->code_length; ++i)
3020 if (jsr_ptrs[i] != NULL)
3022 subr_info *info = jsr_ptrs[i];
3023 while (info != NULL)
3025 subr_info *next = info->next;
3031 _Jv_Free (jsr_ptrs);
3034 while (utf8_list != NULL)
3036 linked_utf8 *n = utf8_list->next;
3037 _Jv_Free (utf8_list->val);
3038 _Jv_Free (utf8_list);
3042 while (entry_points != NULL)
3044 subr_entry_info *next = entry_points->next;
3045 _Jv_Free (entry_points);
3046 entry_points = next;
3052 _Jv_VerifyMethod (_Jv_InterpMethod *meth)
3054 _Jv_BytecodeVerifier v (meth);
3055 v.verify_instructions ();
3057 #endif /* INTERPRETER */