1 // defineclass.cc - defining a class from .class format.
3 /* Copyright (C) 2001 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 // Writte by Tom Tromey <tromey@redhat.com>
17 #include <java-insns.h>
18 #include <java-interp.h>
22 #include <java/lang/Class.h>
23 #include <java/lang/VerifyError.h>
24 #include <java/lang/Throwable.h>
25 #include <java/lang/reflect/Modifier.h>
26 #include <java/lang/StringBuffer.h>
30 // * read more about when classes must be loaded
31 // * class loader madness
32 // * Lots and lots of debugging and testing
33 // * type representation is still ugly. look for the big switches
34 // * at least one GC problem :-(
37 // This is global because __attribute__ doesn't seem to work on static
39 static void verify_fail (char *msg
, jint pc
= -1)
40 __attribute__ ((__noreturn__
));
42 class _Jv_BytecodeVerifier
46 static const int FLAG_INSN_START
= 1;
47 static const int FLAG_BRANCH_TARGET
= 2;
48 static const int FLAG_JSR_TARGET
= 4;
56 // The PC corresponding to the start of the current instruction.
59 // The current state of the stack, locals, etc.
62 // We store the state at branch targets, for merging. This holds
66 // We keep a linked list of all the PCs which we must reverify.
67 // The link is done using the PC values. This is the head of the
71 // We keep some flags for each instruction. The values are the
72 // FLAG_* constants defined above.
75 // We need to keep track of which instructions can call a given
76 // subroutine. FIXME: this is inefficient. We keep a linked list
77 // of all calling `jsr's at at each jsr target.
80 // The current top of the stack, in terms of slots.
82 // The current depth of the stack. This will be larger than
83 // STACKTOP when wide types are on the stack.
86 // The bytecode itself.
87 unsigned char *bytecode
;
89 _Jv_InterpException
*exception
;
94 _Jv_InterpMethod
*current_method
;
96 // This enum holds a list of tags for all the different types we
97 // need to handle. Reference types are treated specially by the
103 // The values for primitive types are chosen to correspond to values
104 // specified to newarray.
114 // Used when overwriting second word of a double or long in the
115 // local variables. Also used after merging local variable states
116 // to indicate an unusable value.
121 // Everything after `reference_type' must be a reference type.
124 unresolved_reference_type
,
125 uninitialized_reference_type
,
126 uninitialized_unresolved_reference_type
129 // Return the type_val corresponding to a primitive signature
130 // character. For instance `I' returns `int.class'.
131 static type_val
get_type_val_for_signature (jchar sig
)
164 verify_fail ("invalid signature");
169 // Return the type_val corresponding to a primitive class.
170 static type_val
get_type_val_for_signature (jclass k
)
172 return get_type_val_for_signature ((jchar
) k
->method_count
);
175 // This is like _Jv_IsAssignableFrom, but it works even if SOURCE or
176 // TARGET haven't been prepared.
177 static bool is_assignable_from_slow (jclass target
, jclass source
)
179 // This will terminate when SOURCE==Object.
182 if (source
== target
)
185 if (target
->isPrimitive () || source
->isPrimitive ())
188 // _Jv_IsAssignableFrom can handle a target which is an
189 // interface even if it hasn't been prepared.
190 if ((target
->state
> JV_STATE_LINKED
|| target
->isInterface ())
191 && source
->state
> JV_STATE_LINKED
)
192 return _Jv_IsAssignableFrom (target
, source
);
194 if (target
->isArray ())
196 if (! source
->isArray ())
198 target
= target
->getComponentType ();
199 source
= source
->getComponentType ();
201 else if (target
->isInterface ())
203 for (int i
= 0; i
< source
->interface_count
; ++i
)
205 // We use a recursive call because we also need to
206 // check superinterfaces.
207 if (is_assignable_from_slow (target
, source
->interfaces
[i
]))
212 else if (target
== &java::lang::Object::class$
)
214 else if (source
->isInterface ()
215 || source
== &java::lang::Object::class$
)
218 source
= source
->getSuperclass ();
222 // This is used to keep track of which `jsr's correspond to a given
226 // PC of the instruction just after the jsr.
232 // The `type' class is used to represent a single type in the
238 // Some associated data.
241 // For a resolved reference type, this is a pointer to the class.
243 // For other reference types, this it the name of the class.
246 // This is used when constructing a new object. It is the PC of the
247 // `new' instruction which created the object. We use the special
248 // value -2 to mean that this is uninitialized, and the special
249 // value -1 for the case where the current method is itself the
253 static const int UNINIT
= -2;
254 static const int SELF
= -1;
256 // Basic constructor.
259 key
= unsuitable_type
;
264 // Make a new instance given the type tag. We assume a generic
265 // `reference_type' means Object.
270 if (key
== reference_type
)
271 data
.klass
= &java::lang::Object::class$
;
275 // Make a new instance given a class.
278 key
= reference_type
;
283 // Make a new instance given the name of a class.
284 type (_Jv_Utf8Const
*n
)
286 key
= unresolved_reference_type
;
299 // These operators are required because libgcj can't link in
301 void *operator new[] (size_t bytes
)
303 return _Jv_Malloc (bytes
);
306 void operator delete[] (void *mem
)
311 type
& operator= (type_val k
)
319 type
& operator= (const type
& t
)
327 // Promote a numeric type.
330 if (key
== boolean_type
|| key
== char_type
331 || key
== byte_type
|| key
== short_type
)
336 // If *THIS is an unresolved reference type, resolve it.
339 if (key
!= unresolved_reference_type
340 && key
!= uninitialized_unresolved_reference_type
)
343 // FIXME: class loader
344 using namespace java::lang
;
345 // We might see either kind of name. Sigh.
346 if (data
.name
->data
[0] == 'L'
347 && data
.name
->data
[data
.name
->length
- 1] == ';')
348 data
.klass
= _Jv_FindClassFromSignature (data
.name
->data
, NULL
);
350 data
.klass
= Class::forName (_Jv_NewStringUtf8Const (data
.name
),
352 key
= (key
== unresolved_reference_type
354 : uninitialized_reference_type
);
357 // Mark this type as the uninitialized result of `new'.
358 void set_uninitialized (int npc
)
360 if (key
== reference_type
)
361 key
= uninitialized_reference_type
;
362 else if (key
== unresolved_reference_type
)
363 key
= uninitialized_unresolved_reference_type
;
365 verify_fail ("internal error in type::uninitialized");
369 // Mark this type as now initialized.
370 void set_initialized (int npc
)
372 if (npc
!= UNINIT
&& pc
== npc
373 && (key
== uninitialized_reference_type
374 || key
== uninitialized_unresolved_reference_type
))
376 key
= (key
== uninitialized_reference_type
378 : unresolved_reference_type
);
384 // Return true if an object of type K can be assigned to a variable
385 // of type *THIS. Handle various special cases too. Might modify
386 // *THIS or K. Note however that this does not perform numeric
388 bool compatible (type
&k
)
390 // Any type is compatible with the unsuitable type.
391 if (key
== unsuitable_type
)
394 if (key
< reference_type
|| k
.key
< reference_type
)
397 // The `null' type is convertible to any reference type.
398 // FIXME: is this correct for THIS?
399 if (key
== null_type
|| k
.key
== null_type
)
402 // Any reference type is convertible to Object. This is a special
403 // case so we don't need to unnecessarily resolve a class.
404 if (key
== reference_type
405 && data
.klass
== &java::lang::Object::class$
)
408 // An initialized type and an uninitialized type are not
410 if (isinitialized () != k
.isinitialized ())
413 // Two uninitialized objects are compatible if either:
414 // * The PCs are identical, or
415 // * One PC is UNINIT.
416 if (! isinitialized ())
418 if (pc
!= k
.pc
&& pc
!= UNINIT
&& k
.pc
!= UNINIT
)
422 // Two unresolved types are equal if their names are the same.
425 && _Jv_equalUtf8Consts (data
.name
, k
.data
.name
))
428 // We must resolve both types and check assignability.
431 return is_assignable_from_slow (data
.klass
, k
.data
.klass
);
436 return key
== void_type
;
441 return key
== long_type
|| key
== double_type
;
444 // Return number of stack or local variable slots taken by this
448 return iswide () ? 2 : 1;
451 bool isarray () const
453 // We treat null_type as not an array. This is ok based on the
454 // current uses of this method.
455 if (key
== reference_type
)
456 return data
.klass
->isArray ();
457 else if (key
== unresolved_reference_type
)
458 return data
.name
->data
[0] == '[';
465 if (key
!= reference_type
)
467 return data
.klass
->isInterface ();
473 if (key
!= reference_type
)
475 using namespace java::lang::reflect
;
476 return Modifier::isAbstract (data
.klass
->getModifiers ());
479 // Return the element type of an array.
482 // FIXME: maybe should do string manipulation here.
484 if (key
!= reference_type
)
485 verify_fail ("programmer error in type::element_type()");
487 jclass k
= data
.klass
->getComponentType ();
488 if (k
->isPrimitive ())
489 return type (get_type_val_for_signature (k
));
493 // Return the array type corresponding to an initialized
494 // reference. We could expand this to work for other kinds of
495 // types, but currently we don't need to.
498 // Resolving isn't ideal, because it might force us to load
499 // another class, but it's easy. FIXME?
500 if (key
== unresolved_reference_type
)
503 if (key
== reference_type
)
504 return type (_Jv_GetArrayClass (data
.klass
,
505 data
.klass
->getClassLoader ()));
507 verify_fail ("internal error in type::to_array()");
510 bool isreference () const
512 return key
>= reference_type
;
520 bool isinitialized () const
522 return (key
== reference_type
524 || key
== unresolved_reference_type
);
527 bool isresolved () const
529 return (key
== reference_type
531 || key
== uninitialized_reference_type
);
534 void verify_dimensions (int ndims
)
536 // The way this is written, we don't need to check isarray().
537 if (key
== reference_type
)
539 jclass k
= data
.klass
;
540 while (k
->isArray () && ndims
> 0)
542 k
= k
->getComponentType ();
548 // We know KEY == unresolved_reference_type.
549 char *p
= data
.name
->data
;
550 while (*p
++ == '[' && ndims
-- > 0)
555 verify_fail ("array type has fewer dimensions than required");
558 // Merge OLD_TYPE into this. On error throw exception.
559 bool merge (type
& old_type
, bool local_semantics
= false)
561 bool changed
= false;
562 bool refo
= old_type
.isreference ();
563 bool refn
= isreference ();
566 if (old_type
.key
== null_type
)
568 else if (key
== null_type
)
573 else if (isinitialized () != old_type
.isinitialized ())
574 verify_fail ("merging initialized and uninitialized types");
577 if (! isinitialized ())
581 else if (old_type
.pc
== UNINIT
)
583 else if (pc
!= old_type
.pc
)
584 verify_fail ("merging different uninitialized types");
588 && ! old_type
.isresolved ()
589 && _Jv_equalUtf8Consts (data
.name
, old_type
.data
.name
))
591 // Types are identical.
598 jclass k
= data
.klass
;
599 jclass oldk
= old_type
.data
.klass
;
602 while (k
->isArray () && oldk
->isArray ())
605 k
= k
->getComponentType ();
606 oldk
= oldk
->getComponentType ();
609 // This loop will end when we hit Object.
612 if (is_assignable_from_slow (k
, oldk
))
614 k
= k
->getSuperclass ();
620 while (arraycount
> 0)
622 // FIXME: Class loader.
623 k
= _Jv_GetArrayClass (k
, NULL
);
631 else if (refo
|| refn
|| key
!= old_type
.key
)
635 key
= unsuitable_type
;
639 verify_fail ("unmergeable type");
645 // This class holds all the state information we need for a given
649 // Current top of stack.
651 // Current stack depth. This is like the top of stack but it
652 // includes wide variable information.
656 // The local variables.
658 // This is used in subroutines to keep track of which local
659 // variables have been accessed.
661 // If not 0, then we are in a subroutine. The value is the PC of
662 // the subroutine's entry point. We can use 0 as an exceptional
663 // value because PC=0 can never be a subroutine.
665 // This is used to keep a linked list of all the states which
666 // require re-verification. We use the PC to keep track.
669 // INVALID marks a state which is not on the linked list of states
670 // requiring reverification.
671 static const int INVALID
= -1;
672 // NO_NEXT marks the state at the end of the reverification list.
673 static const int NO_NEXT
= -2;
679 local_changed
= NULL
;
682 state (int max_stack
, int max_locals
)
686 stack
= new type
[max_stack
];
687 for (int i
= 0; i
< max_stack
; ++i
)
688 stack
[i
] = unsuitable_type
;
689 locals
= new type
[max_locals
];
690 local_changed
= (bool *) _Jv_Malloc (sizeof (bool) * max_locals
);
691 for (int i
= 0; i
< max_locals
; ++i
)
693 locals
[i
] = unsuitable_type
;
694 local_changed
[i
] = false;
700 state (const state
*copy
, int max_stack
, int max_locals
)
702 stack
= new type
[max_stack
];
703 locals
= new type
[max_locals
];
704 local_changed
= (bool *) _Jv_Malloc (sizeof (bool) * max_locals
);
716 _Jv_Free (local_changed
);
719 void *operator new[] (size_t bytes
)
721 return _Jv_Malloc (bytes
);
724 void operator delete[] (void *mem
)
729 void *operator new (size_t bytes
)
731 return _Jv_Malloc (bytes
);
734 void operator delete (void *mem
)
739 void copy (const state
*copy
, int max_stack
, int max_locals
)
741 stacktop
= copy
->stacktop
;
742 stackdepth
= copy
->stackdepth
;
743 subroutine
= copy
->subroutine
;
744 for (int i
= 0; i
< max_stack
; ++i
)
745 stack
[i
] = copy
->stack
[i
];
746 for (int i
= 0; i
< max_locals
; ++i
)
748 locals
[i
] = copy
->locals
[i
];
749 local_changed
[i
] = copy
->local_changed
[i
];
751 // Don't modify `next'.
754 // Modify this state to reflect entry to an exception handler.
755 void set_exception (type t
, int max_stack
)
760 for (int i
= stacktop
; i
< max_stack
; ++i
)
761 stack
[i
] = unsuitable_type
;
763 // FIXME: subroutine handling?
766 // Merge STATE into this state. Destructively modifies this state.
767 // Returns true if the new state was in fact changed. Will throw an
768 // exception if the states are not mergeable.
769 bool merge (state
*state_old
, bool ret_semantics
,
772 bool changed
= false;
774 // Merge subroutine states. *THIS and *STATE_OLD must be in the
775 // same subroutine. Also, recursive subroutine calls must be
777 if (subroutine
== state_old
->subroutine
)
781 else if (subroutine
== 0)
783 subroutine
= state_old
->subroutine
;
787 verify_fail ("subroutines merged");
790 if (state_old
->stacktop
!= stacktop
)
791 verify_fail ("stack sizes differ");
792 for (int i
= 0; i
< state_old
->stacktop
; ++i
)
794 if (stack
[i
].merge (state_old
->stack
[i
]))
798 // Merge local variables.
799 for (int i
= 0; i
< max_locals
; ++i
)
801 if (! ret_semantics
|| local_changed
[i
])
803 if (locals
[i
].merge (state_old
->locals
[i
], true))
810 // If we're in a subroutine, we must compute the union of
811 // all the changed local variables.
812 if (state_old
->local_changed
[i
])
819 // Throw an exception if there is an uninitialized object on the
820 // stack or in a local variable. EXCEPTION_SEMANTICS controls
821 // whether we're using backwards-branch or exception-handing
823 void check_no_uninitialized_objects (int max_locals
,
824 bool exception_semantics
= false)
826 if (! exception_semantics
)
828 for (int i
= 0; i
< stacktop
; ++i
)
829 if (stack
[i
].isreference () && ! stack
[i
].isinitialized ())
830 verify_fail ("uninitialized object on stack");
833 for (int i
= 0; i
< max_locals
; ++i
)
834 if (locals
[i
].isreference () && ! locals
[i
].isinitialized ())
835 verify_fail ("uninitialized object in local variable");
838 // Note that a local variable was accessed or modified.
839 void note_variable (int index
)
842 local_changed
[index
] = true;
845 // Mark each `new'd object we know of that was allocated at PC as
847 void set_initialized (int pc
, int max_locals
)
849 for (int i
= 0; i
< stacktop
; ++i
)
850 stack
[i
].set_initialized (pc
);
851 for (int i
= 0; i
< max_locals
; ++i
)
852 locals
[i
].set_initialized (pc
);
858 if (current_state
->stacktop
<= 0)
859 verify_fail ("stack empty", start_PC
);
860 type r
= current_state
->stack
[--current_state
->stacktop
];
861 current_state
->stackdepth
-= r
.depth ();
862 if (current_state
->stackdepth
< 0)
863 verify_fail ("stack empty", start_PC
);
871 verify_fail ("narrow pop of wide type", start_PC
);
879 verify_fail ("wide pop of narrow type", start_PC
);
883 type
pop_type (type match
)
887 if (! match
.compatible (t
))
888 verify_fail ("incompatible type on stack", start_PC
);
892 void push_type (type t
)
894 // If T is a numeric type like short, promote it to int.
897 int depth
= t
.depth ();
898 if (current_state
->stackdepth
+ depth
> current_method
->max_stack
)
899 verify_fail ("stack overflow");
900 current_state
->stack
[current_state
->stacktop
++] = t
;
901 current_state
->stackdepth
+= depth
;
904 void set_variable (int index
, type t
)
906 // If T is a numeric type like short, promote it to int.
909 int depth
= t
.depth ();
910 if (index
> current_method
->max_locals
- depth
)
911 verify_fail ("invalid local variable");
912 current_state
->locals
[index
] = t
;
913 current_state
->note_variable (index
);
917 current_state
->locals
[index
+ 1] = continuation_type
;
918 current_state
->note_variable (index
+ 1);
920 if (index
> 0 && current_state
->locals
[index
- 1].iswide ())
922 current_state
->locals
[index
- 1] = unsuitable_type
;
923 // There's no need to call note_variable here.
927 type
get_variable (int index
, type t
)
929 int depth
= t
.depth ();
930 if (index
> current_method
->max_locals
- depth
)
931 verify_fail ("invalid local variable", start_PC
);
932 if (! t
.compatible (current_state
->locals
[index
]))
933 verify_fail ("incompatible type in local variable", start_PC
);
936 type
t (continuation_type
);
937 if (! current_state
->locals
[index
+ 1].compatible (t
))
938 verify_fail ("invalid local variable", start_PC
);
940 current_state
->note_variable (index
);
941 return current_state
->locals
[index
];
944 // Make sure ARRAY is an array type and that its elements are
945 // compatible with type ELEMENT. Returns the actual element type.
946 type
require_array_type (type array
, type element
)
948 if (! array
.isarray ())
949 verify_fail ("array required");
951 type t
= array
.element_type ();
952 if (! element
.compatible (t
))
954 // Special case for byte arrays, which must also be boolean
957 if (element
.key
== byte_type
)
959 type
e2 (boolean_type
);
960 ok
= e2
.compatible (t
);
963 verify_fail ("incompatible array element type");
966 // Return T and not ELEMENT, because T might be specialized.
972 if (PC
>= current_method
->code_length
)
973 verify_fail ("premature end of bytecode");
974 return (jint
) bytecode
[PC
++] & 0xff;
979 jint b1
= get_byte ();
980 jint b2
= get_byte ();
981 return (jint
) ((b1
<< 8) | b2
) & 0xffff;
986 jint b1
= get_byte ();
987 jint b2
= get_byte ();
988 jshort s
= (b1
<< 8) | b2
;
994 jint b1
= get_byte ();
995 jint b2
= get_byte ();
996 jint b3
= get_byte ();
997 jint b4
= get_byte ();
998 return (b1
<< 24) | (b2
<< 16) | (b3
<< 8) | b4
;
1001 int compute_jump (int offset
)
1003 int npc
= start_PC
+ offset
;
1004 if (npc
< 0 || npc
>= current_method
->code_length
)
1005 verify_fail ("branch out of range", start_PC
);
1009 // Merge the indicated state into a new state and schedule a new PC if
1010 // there is a change. If RET_SEMANTICS is true, then we are merging
1011 // from a `ret' instruction into the instruction after a `jsr'. This
1012 // is a special case with its own modified semantics.
1013 void push_jump_merge (int npc
, state
*nstate
, bool ret_semantics
= false)
1015 bool changed
= true;
1016 if (states
[npc
] == NULL
)
1018 // FIXME: what if we reach this code from a `ret'?
1020 states
[npc
] = new state (nstate
, current_method
->max_stack
,
1021 current_method
->max_locals
);
1024 changed
= nstate
->merge (states
[npc
], ret_semantics
,
1025 current_method
->max_stack
);
1027 if (changed
&& states
[npc
]->next
== state::INVALID
)
1029 // The merge changed the state, and the new PC isn't yet on our
1030 // list of PCs to re-verify.
1031 states
[npc
]->next
= next_verify_pc
;
1032 next_verify_pc
= npc
;
1036 void push_jump (int offset
)
1038 int npc
= compute_jump (offset
);
1040 current_state
->check_no_uninitialized_objects (current_method
->max_locals
);
1041 push_jump_merge (npc
, current_state
);
1044 void push_exception_jump (type t
, int pc
)
1046 current_state
->check_no_uninitialized_objects (current_method
->max_locals
,
1048 state
s (current_state
, current_method
->max_stack
,
1049 current_method
->max_locals
);
1050 s
.set_exception (t
, current_method
->max_stack
);
1051 push_jump_merge (pc
, &s
);
1056 int npc
= next_verify_pc
;
1057 if (npc
!= state::NO_NEXT
)
1059 next_verify_pc
= states
[npc
]->next
;
1060 states
[npc
]->next
= state::INVALID
;
1065 void invalidate_pc ()
1067 PC
= state::NO_NEXT
;
1070 void note_branch_target (int pc
, bool is_jsr_target
= false)
1072 if (pc
<= PC
&& ! (flags
[pc
] & FLAG_INSN_START
))
1073 verify_fail ("branch not to instruction start");
1074 flags
[pc
] |= FLAG_BRANCH_TARGET
;
1077 // Record the jsr which called this instruction.
1078 subr_info
*info
= (subr_info
*) _Jv_Malloc (sizeof (subr_info
));
1080 info
->next
= jsr_ptrs
[pc
];
1081 jsr_ptrs
[pc
] = info
;
1082 flags
[pc
] |= FLAG_JSR_TARGET
;
1086 void skip_padding ()
1088 while ((PC
% 4) > 0)
1089 if (get_byte () != 0)
1090 verify_fail ("found nonzero padding byte");
1093 // Return the subroutine to which the instruction at PC belongs.
1094 int get_subroutine (int pc
)
1096 if (states
[pc
] == NULL
)
1098 return states
[pc
]->subroutine
;
1101 // Do the work for a `ret' instruction. INDEX is the index into the
1103 void handle_ret_insn (int index
)
1105 get_variable (index
, return_address_type
);
1107 int csub
= current_state
->subroutine
;
1109 verify_fail ("no subroutine");
1111 for (subr_info
*subr
= jsr_ptrs
[csub
]; subr
!= NULL
; subr
= subr
->next
)
1113 // Temporarily modify the current state so it looks like we're
1114 // in the enclosing context.
1115 current_state
->subroutine
= get_subroutine (subr
->pc
);
1117 current_state
->check_no_uninitialized_objects (current_method
->max_locals
);
1118 push_jump_merge (subr
->pc
, current_state
, true);
1121 current_state
->subroutine
= csub
;
1125 // We're in the subroutine SUB, calling a subroutine at DEST. Make
1126 // sure this subroutine isn't already on the stack.
1127 void check_nonrecursive_call (int sub
, int dest
)
1132 verify_fail ("recursive subroutine call");
1133 for (subr_info
*info
= jsr_ptrs
[sub
]; info
!= NULL
; info
= info
->next
)
1134 check_nonrecursive_call (get_subroutine (info
->pc
), dest
);
1137 void handle_jsr_insn (int offset
)
1139 int npc
= compute_jump (offset
);
1142 current_state
->check_no_uninitialized_objects (current_method
->max_locals
);
1143 check_nonrecursive_call (current_state
->subroutine
, npc
);
1145 // Temporarily modify the current state so that it looks like we are
1146 // in the subroutine.
1147 push_type (return_address_type
);
1148 int save
= current_state
->subroutine
;
1149 current_state
->subroutine
= npc
;
1151 // Merge into the subroutine.
1152 push_jump_merge (npc
, current_state
);
1154 // Undo our modifications.
1155 current_state
->subroutine
= save
;
1156 pop_type (return_address_type
);
1159 jclass
construct_primitive_array_type (type_val prim
)
1165 k
= JvPrimClass (boolean
);
1168 k
= JvPrimClass (char);
1171 k
= JvPrimClass (float);
1174 k
= JvPrimClass (double);
1177 k
= JvPrimClass (byte
);
1180 k
= JvPrimClass (short);
1183 k
= JvPrimClass (int);
1186 k
= JvPrimClass (long);
1189 verify_fail ("unknown type in construct_primitive_array_type");
1191 k
= _Jv_GetArrayClass (k
, NULL
);
1195 // This pass computes the location of branch targets and also
1196 // instruction starts.
1197 void branch_prepass ()
1199 flags
= (char *) _Jv_Malloc (current_method
->code_length
);
1200 jsr_ptrs
= (subr_info
**) _Jv_Malloc (sizeof (subr_info
*)
1201 * current_method
->code_length
);
1203 for (int i
= 0; i
< current_method
->code_length
; ++i
)
1209 bool last_was_jsr
= false;
1212 while (PC
< current_method
->code_length
)
1214 flags
[PC
] |= FLAG_INSN_START
;
1216 // If the previous instruction was a jsr, then the next
1217 // instruction is a branch target -- the branch being the
1218 // corresponding `ret'.
1220 note_branch_target (PC
);
1221 last_was_jsr
= false;
1224 java_opcode opcode
= (java_opcode
) bytecode
[PC
++];
1228 case op_aconst_null
:
1364 case op_monitorenter
:
1365 case op_monitorexit
:
1373 case op_arraylength
:
1405 case op_invokespecial
:
1406 case op_invokestatic
:
1407 case op_invokevirtual
:
1411 case op_multianewarray
:
1417 last_was_jsr
= true;
1436 note_branch_target (compute_jump (get_short ()), last_was_jsr
);
1439 case op_tableswitch
:
1442 note_branch_target (compute_jump (get_int ()));
1443 jint low
= get_int ();
1444 jint hi
= get_int ();
1446 verify_fail ("invalid tableswitch", start_PC
);
1447 for (int i
= low
; i
<= hi
; ++i
)
1448 note_branch_target (compute_jump (get_int ()));
1452 case op_lookupswitch
:
1455 note_branch_target (compute_jump (get_int ()));
1456 int npairs
= get_int ();
1458 verify_fail ("too few pairs in lookupswitch", start_PC
);
1459 while (npairs
-- > 0)
1462 note_branch_target (compute_jump (get_int ()));
1467 case op_invokeinterface
:
1475 opcode
= (java_opcode
) get_byte ();
1477 if (opcode
== op_iinc
)
1483 last_was_jsr
= true;
1486 note_branch_target (compute_jump (get_int ()), last_was_jsr
);
1490 verify_fail ("unrecognized instruction in branch_prepass",
1494 // See if any previous branch tried to branch to the middle of
1495 // this instruction.
1496 for (int pc
= start_PC
+ 1; pc
< PC
; ++pc
)
1498 if ((flags
[pc
] & FLAG_BRANCH_TARGET
))
1499 verify_fail ("branch to middle of instruction", pc
);
1503 // Verify exception handlers.
1504 for (int i
= 0; i
< current_method
->exc_count
; ++i
)
1506 if (! (flags
[exception
[i
].handler_pc
] & FLAG_INSN_START
))
1507 verify_fail ("exception handler not at instruction start",
1508 exception
[i
].handler_pc
);
1509 if (exception
[i
].start_pc
> exception
[i
].end_pc
)
1510 verify_fail ("exception range inverted");
1511 if (! (flags
[exception
[i
].start_pc
] & FLAG_INSN_START
))
1512 verify_fail ("exception start not at instruction start",
1513 exception
[i
].start_pc
);
1514 else if (! (flags
[exception
[i
].end_pc
] & FLAG_INSN_START
))
1515 verify_fail ("exception end not at instruction start",
1516 exception
[i
].end_pc
);
1518 flags
[exception
[i
].handler_pc
] |= FLAG_BRANCH_TARGET
;
1522 void check_pool_index (int index
)
1524 if (index
< 0 || index
>= current_class
->constants
.size
)
1525 verify_fail ("constant pool index out of range", start_PC
);
1528 type
check_class_constant (int index
)
1530 check_pool_index (index
);
1531 _Jv_Constants
*pool
= ¤t_class
->constants
;
1532 if (pool
->tags
[index
] == JV_CONSTANT_ResolvedClass
)
1533 return type (pool
->data
[index
].clazz
);
1534 else if (pool
->tags
[index
] == JV_CONSTANT_Class
)
1535 return type (pool
->data
[index
].utf8
);
1536 verify_fail ("expected class constant", start_PC
);
1539 type
check_constant (int index
)
1541 check_pool_index (index
);
1542 _Jv_Constants
*pool
= ¤t_class
->constants
;
1543 if (pool
->tags
[index
] == JV_CONSTANT_ResolvedString
1544 || pool
->tags
[index
] == JV_CONSTANT_String
)
1545 return type (&java::lang::String::class$
);
1546 else if (pool
->tags
[index
] == JV_CONSTANT_Integer
)
1547 return type (int_type
);
1548 else if (pool
->tags
[index
] == JV_CONSTANT_Float
)
1549 return type (float_type
);
1550 verify_fail ("String, int, or float constant expected", start_PC
);
1553 type
check_wide_constant (int index
)
1555 check_pool_index (index
);
1556 _Jv_Constants
*pool
= ¤t_class
->constants
;
1557 if (pool
->tags
[index
] == JV_CONSTANT_Long
)
1558 return type (long_type
);
1559 else if (pool
->tags
[index
] == JV_CONSTANT_Double
)
1560 return type (double_type
);
1561 verify_fail ("long or double constant expected", start_PC
);
1564 // Helper for both field and method. These are laid out the same in
1565 // the constant pool.
1566 type
handle_field_or_method (int index
, int expected
,
1567 _Jv_Utf8Const
**name
,
1568 _Jv_Utf8Const
**fmtype
)
1570 check_pool_index (index
);
1571 _Jv_Constants
*pool
= ¤t_class
->constants
;
1572 if (pool
->tags
[index
] != expected
)
1573 verify_fail ("didn't see expected constant", start_PC
);
1574 // Once we know we have a Fieldref or Methodref we assume that it
1575 // is correctly laid out in the constant pool. I think the code
1576 // in defineclass.cc guarantees this.
1577 _Jv_ushort class_index
, name_and_type_index
;
1578 _Jv_loadIndexes (&pool
->data
[index
],
1580 name_and_type_index
);
1581 _Jv_ushort name_index
, desc_index
;
1582 _Jv_loadIndexes (&pool
->data
[name_and_type_index
],
1583 name_index
, desc_index
);
1585 *name
= pool
->data
[name_index
].utf8
;
1586 *fmtype
= pool
->data
[desc_index
].utf8
;
1588 return check_class_constant (class_index
);
1591 // Return field's type, compute class' type if requested.
1592 type
check_field_constant (int index
, type
*class_type
= NULL
)
1594 _Jv_Utf8Const
*name
, *field_type
;
1595 type ct
= handle_field_or_method (index
,
1596 JV_CONSTANT_Fieldref
,
1597 &name
, &field_type
);
1600 if (field_type
->data
[0] == '[' || field_type
->data
[0] == 'L')
1601 return type (field_type
);
1602 return get_type_val_for_signature (field_type
->data
[0]);
1605 type
check_method_constant (int index
, bool is_interface
,
1606 _Jv_Utf8Const
**method_name
,
1607 _Jv_Utf8Const
**method_signature
)
1609 return handle_field_or_method (index
,
1611 ? JV_CONSTANT_InterfaceMethodref
1612 : JV_CONSTANT_Methodref
),
1613 method_name
, method_signature
);
1616 type
get_one_type (char *&p
)
1634 // FIXME! This will get collected!
1635 _Jv_Utf8Const
*name
= _Jv_makeUtf8Const (start
, p
- start
);
1639 // Casting to jchar here is ok since we are looking at an ASCII
1641 type_val rt
= get_type_val_for_signature (jchar (v
));
1643 if (arraycount
== 0)
1645 // Callers of this function eventually push their arguments on
1646 // the stack. So, promote them here.
1647 return type (rt
).promote ();
1650 jclass k
= construct_primitive_array_type (rt
);
1651 while (--arraycount
> 0)
1652 k
= _Jv_GetArrayClass (k
, NULL
);
1656 void compute_argument_types (_Jv_Utf8Const
*signature
,
1659 char *p
= signature
->data
;
1665 types
[i
++] = get_one_type (p
);
1668 type
compute_return_type (_Jv_Utf8Const
*signature
)
1670 char *p
= signature
->data
;
1674 return get_one_type (p
);
1677 void check_return_type (type onstack
)
1679 type rt
= compute_return_type (current_method
->self
->signature
);
1680 if (! rt
.compatible (onstack
))
1681 verify_fail ("incompatible return type", start_PC
);
1684 void verify_instructions_0 ()
1686 current_state
= new state (current_method
->max_stack
,
1687 current_method
->max_locals
);
1695 using namespace java::lang::reflect
;
1696 if (! Modifier::isStatic (current_method
->self
->accflags
))
1698 type
kurr (current_class
);
1699 if (_Jv_equalUtf8Consts (current_method
->self
->name
, gcj::init_name
))
1700 kurr
.set_uninitialized (type::SELF
);
1701 set_variable (0, kurr
);
1705 // We have to handle wide arguments specially here.
1706 int arg_count
= _Jv_count_arguments (current_method
->self
->signature
);
1707 type arg_types
[arg_count
];
1708 compute_argument_types (current_method
->self
->signature
, arg_types
);
1709 for (int i
= 0; i
< arg_count
; ++i
)
1711 set_variable (var
, arg_types
[i
]);
1713 if (arg_types
[i
].iswide ())
1718 states
= (state
**) _Jv_Malloc (sizeof (state
*)
1719 * current_method
->code_length
);
1720 for (int i
= 0; i
< current_method
->code_length
; ++i
)
1723 next_verify_pc
= state::NO_NEXT
;
1727 // If the PC was invalidated, get a new one from the work list.
1728 if (PC
== state::NO_NEXT
)
1731 if (PC
== state::INVALID
)
1732 verify_fail ("saw state::INVALID", start_PC
);
1733 if (PC
== state::NO_NEXT
)
1735 // Set up the current state.
1736 *current_state
= *states
[PC
];
1739 // Control can't fall off the end of the bytecode.
1740 if (PC
>= current_method
->code_length
)
1741 verify_fail ("fell off end");
1743 if (states
[PC
] != NULL
)
1745 // We've already visited this instruction. So merge the
1746 // states together. If this yields no change then we don't
1747 // have to re-verify.
1748 if (! current_state
->merge (states
[PC
], false,
1749 current_method
->max_stack
))
1754 // Save a copy of it for later.
1755 states
[PC
]->copy (current_state
, current_method
->max_stack
,
1756 current_method
->max_locals
);
1758 else if ((flags
[PC
] & FLAG_BRANCH_TARGET
))
1760 // We only have to keep saved state at branch targets.
1761 states
[PC
] = new state (current_state
, current_method
->max_stack
,
1762 current_method
->max_locals
);
1765 // Update states for all active exception handlers. Ordinarily
1766 // there are not many exception handlers. So we simply run
1767 // through them all.
1768 for (int i
= 0; i
< current_method
->exc_count
; ++i
)
1770 if (PC
>= exception
[i
].start_pc
&& PC
< exception
[i
].end_pc
)
1772 type handler
= reference_type
;
1773 if (exception
[i
].handler_type
!= 0)
1774 handler
= check_class_constant (exception
[i
].handler_type
);
1775 push_exception_jump (handler
, exception
[i
].handler_pc
);
1780 java_opcode opcode
= (java_opcode
) bytecode
[PC
++];
1786 case op_aconst_null
:
1787 push_type (null_type
);
1797 push_type (int_type
);
1802 push_type (long_type
);
1808 push_type (float_type
);
1813 push_type (double_type
);
1818 push_type (int_type
);
1823 push_type (int_type
);
1827 push_type (check_constant (get_byte ()));
1830 push_type (check_constant (get_ushort ()));
1833 push_type (check_wide_constant (get_ushort ()));
1837 push_type (get_variable (get_byte (), int_type
));
1840 push_type (get_variable (get_byte (), long_type
));
1843 push_type (get_variable (get_byte (), float_type
));
1846 push_type (get_variable (get_byte (), double_type
));
1849 push_type (get_variable (get_byte (), reference_type
));
1856 push_type (get_variable (opcode
- op_iload_0
, int_type
));
1862 push_type (get_variable (opcode
- op_lload_0
, long_type
));
1868 push_type (get_variable (opcode
- op_fload_0
, float_type
));
1874 push_type (get_variable (opcode
- op_dload_0
, double_type
));
1880 push_type (get_variable (opcode
- op_aload_0
, reference_type
));
1883 pop_type (int_type
);
1884 push_type (require_array_type (pop_type (reference_type
),
1888 pop_type (int_type
);
1889 push_type (require_array_type (pop_type (reference_type
),
1893 pop_type (int_type
);
1894 push_type (require_array_type (pop_type (reference_type
),
1898 pop_type (int_type
);
1899 push_type (require_array_type (pop_type (reference_type
),
1903 pop_type (int_type
);
1904 push_type (require_array_type (pop_type (reference_type
),
1908 pop_type (int_type
);
1909 require_array_type (pop_type (reference_type
), byte_type
);
1910 push_type (int_type
);
1913 pop_type (int_type
);
1914 require_array_type (pop_type (reference_type
), char_type
);
1915 push_type (int_type
);
1918 pop_type (int_type
);
1919 require_array_type (pop_type (reference_type
), short_type
);
1920 push_type (int_type
);
1923 set_variable (get_byte (), pop_type (int_type
));
1926 set_variable (get_byte (), pop_type (long_type
));
1929 set_variable (get_byte (), pop_type (float_type
));
1932 set_variable (get_byte (), pop_type (double_type
));
1935 set_variable (get_byte (), pop_type (reference_type
));
1941 set_variable (opcode
- op_istore_0
, pop_type (int_type
));
1947 set_variable (opcode
- op_lstore_0
, pop_type (long_type
));
1953 set_variable (opcode
- op_fstore_0
, pop_type (float_type
));
1959 set_variable (opcode
- op_dstore_0
, pop_type (double_type
));
1965 set_variable (opcode
- op_astore_0
, pop_type (reference_type
));
1968 pop_type (int_type
);
1969 pop_type (int_type
);
1970 require_array_type (pop_type (reference_type
), int_type
);
1973 pop_type (long_type
);
1974 pop_type (int_type
);
1975 require_array_type (pop_type (reference_type
), long_type
);
1978 pop_type (float_type
);
1979 pop_type (int_type
);
1980 require_array_type (pop_type (reference_type
), float_type
);
1983 pop_type (double_type
);
1984 pop_type (int_type
);
1985 require_array_type (pop_type (reference_type
), double_type
);
1988 pop_type (reference_type
);
1989 pop_type (int_type
);
1990 require_array_type (pop_type (reference_type
), reference_type
);
1993 pop_type (int_type
);
1994 pop_type (int_type
);
1995 require_array_type (pop_type (reference_type
), byte_type
);
1998 pop_type (int_type
);
1999 pop_type (int_type
);
2000 require_array_type (pop_type (reference_type
), char_type
);
2003 pop_type (int_type
);
2004 pop_type (int_type
);
2005 require_array_type (pop_type (reference_type
), short_type
);
2032 type t2
= pop_raw ();
2047 type t
= pop_raw ();
2060 type t1
= pop_raw ();
2078 type t1
= pop_raw ();
2081 type t2
= pop_raw ();
2099 type t3
= pop_raw ();
2137 pop_type (int_type
);
2138 push_type (pop_type (int_type
));
2148 pop_type (long_type
);
2149 push_type (pop_type (long_type
));
2154 pop_type (int_type
);
2155 push_type (pop_type (long_type
));
2162 pop_type (float_type
);
2163 push_type (pop_type (float_type
));
2170 pop_type (double_type
);
2171 push_type (pop_type (double_type
));
2177 push_type (pop_type (int_type
));
2180 push_type (pop_type (long_type
));
2183 push_type (pop_type (float_type
));
2186 push_type (pop_type (double_type
));
2189 get_variable (get_byte (), int_type
);
2193 pop_type (int_type
);
2194 push_type (long_type
);
2197 pop_type (int_type
);
2198 push_type (float_type
);
2201 pop_type (int_type
);
2202 push_type (double_type
);
2205 pop_type (long_type
);
2206 push_type (int_type
);
2209 pop_type (long_type
);
2210 push_type (float_type
);
2213 pop_type (long_type
);
2214 push_type (double_type
);
2217 pop_type (float_type
);
2218 push_type (int_type
);
2221 pop_type (float_type
);
2222 push_type (long_type
);
2225 pop_type (float_type
);
2226 push_type (double_type
);
2229 pop_type (double_type
);
2230 push_type (int_type
);
2233 pop_type (double_type
);
2234 push_type (long_type
);
2237 pop_type (double_type
);
2238 push_type (float_type
);
2241 pop_type (long_type
);
2242 pop_type (long_type
);
2243 push_type (int_type
);
2247 pop_type (float_type
);
2248 pop_type (float_type
);
2249 push_type (int_type
);
2253 pop_type (double_type
);
2254 pop_type (double_type
);
2255 push_type (int_type
);
2263 pop_type (int_type
);
2264 push_jump (get_short ());
2272 pop_type (int_type
);
2273 pop_type (int_type
);
2274 push_jump (get_short ());
2278 pop_type (reference_type
);
2279 pop_type (reference_type
);
2280 push_jump (get_short ());
2283 push_jump (get_short ());
2287 handle_jsr_insn (get_short ());
2290 handle_ret_insn (get_byte ());
2292 case op_tableswitch
:
2294 pop_type (int_type
);
2296 push_jump (get_int ());
2297 jint low
= get_int ();
2298 jint high
= get_int ();
2299 // Already checked LOW -vs- HIGH.
2300 for (int i
= low
; i
<= high
; ++i
)
2301 push_jump (get_int ());
2306 case op_lookupswitch
:
2308 pop_type (int_type
);
2310 push_jump (get_int ());
2311 jint npairs
= get_int ();
2312 // Already checked NPAIRS >= 0.
2314 for (int i
= 0; i
< npairs
; ++i
)
2316 jint key
= get_int ();
2317 if (i
> 0 && key
<= lastkey
)
2318 verify_fail ("lookupswitch pairs unsorted", start_PC
);
2320 push_jump (get_int ());
2326 check_return_type (pop_type (int_type
));
2330 check_return_type (pop_type (long_type
));
2334 check_return_type (pop_type (float_type
));
2338 check_return_type (pop_type (double_type
));
2342 check_return_type (pop_type (reference_type
));
2346 check_return_type (void_type
);
2350 push_type (check_field_constant (get_ushort ()));
2353 pop_type (check_field_constant (get_ushort ()));
2358 type field
= check_field_constant (get_ushort (), &klass
);
2366 type field
= check_field_constant (get_ushort (), &klass
);
2372 case op_invokevirtual
:
2373 case op_invokespecial
:
2374 case op_invokestatic
:
2375 case op_invokeinterface
:
2377 _Jv_Utf8Const
*method_name
, *method_signature
;
2379 = check_method_constant (get_ushort (),
2380 opcode
== op_invokeinterface
,
2383 int arg_count
= _Jv_count_arguments (method_signature
);
2384 if (opcode
== op_invokeinterface
)
2386 int nargs
= get_byte ();
2388 verify_fail ("too few arguments to invokeinterface",
2390 if (get_byte () != 0)
2391 verify_fail ("invokeinterface dummy byte is wrong",
2393 if (nargs
- 1 != arg_count
)
2394 verify_fail ("wrong argument count for invokeinterface",
2398 bool is_init
= false;
2399 if (_Jv_equalUtf8Consts (method_name
, gcj::init_name
))
2402 if (opcode
!= op_invokespecial
)
2403 verify_fail ("can't invoke <init>", start_PC
);
2405 else if (method_name
->data
[0] == '<')
2406 verify_fail ("can't invoke method starting with `<'",
2409 // Pop arguments and check types.
2410 type arg_types
[arg_count
];
2411 compute_argument_types (method_signature
, arg_types
);
2412 for (int i
= arg_count
- 1; i
>= 0; --i
)
2413 pop_type (arg_types
[i
]);
2415 if (opcode
!= op_invokestatic
)
2417 type t
= class_type
;
2420 // In this case the PC doesn't matter.
2421 t
.set_uninitialized (type::UNINIT
);
2425 current_state
->set_initialized (t
.get_pc (),
2426 current_method
->max_locals
);
2429 type rt
= compute_return_type (method_signature
);
2437 type t
= check_class_constant (get_ushort ());
2438 if (t
.isarray () || t
.isinterface () || t
.isabstract ())
2439 verify_fail ("type is array, interface, or abstract",
2441 t
.set_uninitialized (start_PC
);
2448 int atype
= get_byte ();
2449 // We intentionally have chosen constants to make this
2451 if (atype
< boolean_type
|| atype
> long_type
)
2452 verify_fail ("type not primitive", start_PC
);
2453 pop_type (int_type
);
2454 push_type (construct_primitive_array_type (type_val (atype
)));
2458 pop_type (int_type
);
2459 push_type (check_class_constant (get_ushort ()).to_array ());
2461 case op_arraylength
:
2463 type t
= pop_type (reference_type
);
2465 verify_fail ("array type expected", start_PC
);
2466 push_type (int_type
);
2470 pop_type (type (&java::lang::Throwable::class$
));
2474 pop_type (reference_type
);
2475 push_type (check_class_constant (get_ushort ()));
2478 pop_type (reference_type
);
2479 check_class_constant (get_ushort ());
2480 push_type (int_type
);
2482 case op_monitorenter
:
2483 pop_type (reference_type
);
2485 case op_monitorexit
:
2486 pop_type (reference_type
);
2490 switch (get_byte ())
2493 push_type (get_variable (get_ushort (), int_type
));
2496 push_type (get_variable (get_ushort (), long_type
));
2499 push_type (get_variable (get_ushort (), float_type
));
2502 push_type (get_variable (get_ushort (), double_type
));
2505 push_type (get_variable (get_ushort (), reference_type
));
2508 set_variable (get_ushort (), pop_type (int_type
));
2511 set_variable (get_ushort (), pop_type (long_type
));
2514 set_variable (get_ushort (), pop_type (float_type
));
2517 set_variable (get_ushort (), pop_type (double_type
));
2520 set_variable (get_ushort (), pop_type (reference_type
));
2523 handle_ret_insn (get_short ());
2526 get_variable (get_ushort (), int_type
);
2530 verify_fail ("unrecognized wide instruction", start_PC
);
2534 case op_multianewarray
:
2536 type atype
= check_class_constant (get_ushort ());
2537 int dim
= get_byte ();
2539 verify_fail ("too few dimensions to multianewarray", start_PC
);
2540 atype
.verify_dimensions (dim
);
2541 for (int i
= 0; i
< dim
; ++i
)
2542 pop_type (int_type
);
2548 pop_type (reference_type
);
2549 push_jump (get_short ());
2552 push_jump (get_int ());
2556 handle_jsr_insn (get_int ());
2560 // Unrecognized opcode.
2561 verify_fail ("unrecognized instruction in verify_instructions_0",
2569 void verify_instructions ()
2572 verify_instructions_0 ();
2575 _Jv_BytecodeVerifier (_Jv_InterpMethod
*m
)
2578 bytecode
= m
->bytecode ();
2579 exception
= m
->exceptions ();
2580 current_class
= m
->defining_class
;
2587 ~_Jv_BytecodeVerifier ()
2594 _Jv_Free (jsr_ptrs
);
2599 _Jv_VerifyMethod (_Jv_InterpMethod
*meth
)
2601 _Jv_BytecodeVerifier
v (meth
);
2602 v
.verify_instructions ();
2605 // FIXME: add more info, like PC, when required.
2607 verify_fail (char *s
, jint pc
)
2609 using namespace java::lang
;
2610 StringBuffer
*buf
= new StringBuffer ();
2612 buf
->append (JvNewStringLatin1 ("verification failed"));
2615 buf
->append (JvNewStringLatin1 (" at PC "));
2618 buf
->append (JvNewStringLatin1 (": "));
2619 buf
->append (JvNewStringLatin1 (s
));
2620 throw new java::lang::VerifyError (buf
->toString ());
2623 #endif /* INTERPRETER */