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authorupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
committerupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
commit554fd8c5195424bdbcabf5de30fdc183aba391bd (patch)
tree976dc5ab7fddf506dadce60ae936f43f58787092 /gcc/java/verify-impl.c
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+/* Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2008, 2009, 2010
+ Free Software Foundation
+
+ This file is part of libgcj.
+
+This software is copyrighted work licensed under the terms of the
+Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
+details. */
+
+/* Written by Tom Tromey <tromey@redhat.com> */
+
+/* Uncomment this to enable debugging output. */
+/* #define VERIFY_DEBUG */
+
+#include "config.h"
+
+#include "verify.h"
+
+/* Hack to work around namespace pollution from java-tree.h. */
+#undef current_class
+
+/* This is used to mark states which are not scheduled for
+ verification. */
+#define INVALID_STATE ((state *) -1)
+
+static void ATTRIBUTE_PRINTF_1
+debug_print (const char *fmt ATTRIBUTE_UNUSED, ...)
+{
+#ifdef VERIFY_DEBUG
+ va_list ap;
+ va_start (ap, fmt);
+ vfprintf (stderr, fmt, ap);
+ va_end (ap);
+#endif /* VERIFY_DEBUG */
+}
+
+/* This started as a fairly ordinary verifier, and for the most part
+ it remains so. It works in the obvious way, by modeling the effect
+ of each opcode as it is encountered. For most opcodes, this is a
+ straightforward operation.
+
+ This verifier does not do type merging. It used to, but this
+ results in difficulty verifying some relatively simple code
+ involving interfaces, and it pushed some verification work into the
+ interpreter.
+
+ Instead of merging reference types, when we reach a point where two
+ flows of control merge, we simply keep the union of reference types
+ from each branch. Then, when we need to verify a fact about a
+ reference on the stack (e.g., that it is compatible with the
+ argument type of a method), we check to ensure that all possible
+ types satisfy the requirement.
+
+ Another area this verifier differs from the norm is in its handling
+ of subroutines. The JVM specification has some confusing things to
+ say about subroutines. For instance, it makes claims about not
+ allowing subroutines to merge and it rejects recursive subroutines.
+ For the most part these are red herrings; we used to try to follow
+ these things but they lead to problems. For example, the notion of
+ "being in a subroutine" is not well-defined: is an exception
+ handler in a subroutine? If you never execute the `ret' but
+ instead `goto 1' do you remain in the subroutine?
+
+ For clarity on what is really required for type safety, read
+ "Simple Verification Technique for Complex Java Bytecode
+ Subroutines" by Alessandro Coglio. Among other things this paper
+ shows that recursive subroutines are not harmful to type safety.
+ We implement something similar to what he proposes. Note that this
+ means that this verifier will accept code that is rejected by some
+ other verifiers.
+
+ For those not wanting to read the paper, the basic observation is
+ that we can maintain split states in subroutines. We maintain one
+ state for each calling `jsr'. In other words, we re-verify a
+ subroutine once for each caller, using the exact types held by the
+ callers (as opposed to the old approach of merging types and
+ keeping a bitmap registering what did or did not change). This
+ approach lets us continue to verify correctly even when a
+ subroutine is exited via `goto' or `athrow' and not `ret'.
+
+ In some other areas the JVM specification is (mildly) incorrect,
+ so we diverge. For instance, you cannot
+ violate type safety by allocating an object with `new' and then
+ failing to initialize it, no matter how one branches or where one
+ stores the uninitialized reference. See "Improving the official
+ specification of Java bytecode verification" by Alessandro Coglio.
+
+ Note that there's no real point in enforcing that padding bytes or
+ the mystery byte of invokeinterface must be 0, but we do that
+ regardless.
+
+ The verifier is currently neither completely lazy nor eager when it
+ comes to loading classes. It tries to represent types by name when
+ possible, and then loads them when it needs to verify a fact about
+ the type. Checking types by name is valid because we only use
+ names which come from the current class' constant pool. Since all
+ such names are looked up using the same class loader, there is no
+ danger that we might be fooled into comparing different types with
+ the same name.
+
+ In the future we plan to allow for a completely lazy mode of
+ operation, where the verifier will construct a list of type
+ assertions to be checked later.
+
+ Some test cases for the verifier live in the "verify" module of the
+ Mauve test suite. However, some of these are presently
+ (2004-01-20) believed to be incorrect. (More precisely the notion
+ of "correct" is not well-defined, and this verifier differs from
+ others while remaining type-safe.) Some other tests live in the
+ libgcj test suite.
+
+ This verifier is also written to be pluggable. This means that it
+ is intended for use in a variety of environments, not just libgcj.
+ As a result the verifier expects a number of type and method
+ declarations to be declared in "verify.h". The intent is that you
+ recompile the verifier for your particular environment. This
+ approach was chosen so that operations could be inlined in verify.h
+ as much as possible.
+
+ See the verify.h that accompanies this copy of the verifier to see
+ what types, preprocessor defines, and functions must be declared.
+ The interface is ad hoc, but was defined so that it could be
+ implemented to connect to a pure C program.
+*/
+
+#define FLAG_INSN_START 1
+#define FLAG_BRANCH_TARGET 2
+#define FLAG_INSN_SEEN 4
+
+struct state;
+struct type;
+struct ref_intersection;
+
+typedef struct state state;
+typedef struct type type;
+typedef struct ref_intersection ref_intersection;
+
+/*typedef struct state_list state_list;*/
+
+typedef struct state_list
+{
+ state *val;
+ struct state_list *next;
+} state_list;
+
+typedef struct vfy_string_list
+{
+ vfy_string val;
+ struct vfy_string_list *next;
+} vfy_string_list;
+
+typedef struct verifier_context
+{
+ /* The current PC. */
+ int PC;
+ /* The PC corresponding to the start of the current instruction. */
+ int start_PC;
+
+ /* The current state of the stack, locals, etc. */
+ state *current_state;
+
+ /* At each branch target we keep a linked list of all the states we
+ can process at that point. We'll only have multiple states at a
+ given PC if they both have different return-address types in the
+ same stack or local slot. This array is indexed by PC and holds
+ the list of all such states. */
+ state_list **states;
+
+ /* We keep a linked list of all the states which we must reverify.
+ This is the head of the list. */
+ state *next_verify_state;
+
+ /* We keep some flags for each instruction. The values are the
+ FLAG_* constants defined above. This is an array indexed by PC. */
+ char *flags;
+
+ /* The bytecode itself. */
+ const unsigned char *bytecode;
+ /* The exceptions. */
+ vfy_exception *exception;
+
+ /* Defining class. */
+ vfy_jclass current_class;
+ /* This method. */
+ vfy_method *current_method;
+
+ /* A linked list of utf8 objects we allocate. */
+ vfy_string_list *utf8_list;
+
+ /* A linked list of all ref_intersection objects we allocate. */
+ ref_intersection *isect_list;
+} verifier_context;
+
+/* The current verifier's state data. This is maintained by
+ {push/pop}_verifier_context to provide a shorthand form to access
+ the verification state. */
+static GTY(()) verifier_context *vfr;
+
+/* Local function declarations. */
+bool type_initialized (type *t);
+int ref_count_dimensions (ref_intersection *ref);
+
+static void
+verify_fail_pc (const char *s, int pc)
+{
+ vfy_fail (s, pc, vfr->current_class, vfr->current_method);
+}
+
+static void
+verify_fail (const char *s)
+{
+ verify_fail_pc (s, vfr->PC);
+}
+
+/* This enum holds a list of tags for all the different types we
+ need to handle. Reference types are treated specially by the
+ type class. */
+typedef enum type_val
+{
+ void_type,
+
+ /* The values for primitive types are chosen to correspond to values
+ specified to newarray. */
+ boolean_type = 4,
+ char_type = 5,
+ float_type = 6,
+ double_type = 7,
+ byte_type = 8,
+ short_type = 9,
+ int_type = 10,
+ long_type = 11,
+
+ /* Used when overwriting second word of a double or long in the
+ local variables. Also used after merging local variable states
+ to indicate an unusable value. */
+ unsuitable_type,
+ return_address_type,
+ /* This is the second word of a two-word value, i.e., a double or
+ a long. */
+ continuation_type,
+
+ /* Everything after `reference_type' must be a reference type. */
+ reference_type,
+ null_type,
+ uninitialized_reference_type
+} type_val;
+
+/* This represents a merged class type. Some verifiers (including
+ earlier versions of this one) will compute the intersection of
+ two class types when merging states. However, this loses
+ critical information about interfaces implemented by the various
+ classes. So instead we keep track of all the actual classes that
+ have been merged. */
+struct ref_intersection
+{
+ /* Whether or not this type has been resolved. */
+ bool is_resolved;
+
+ /* Actual type data. */
+ union
+ {
+ /* For a resolved reference type, this is a pointer to the class. */
+ vfy_jclass klass;
+ /* For other reference types, this it the name of the class. */
+ vfy_string name;
+ } data;
+
+ /* Link to the next reference in the intersection. */
+ ref_intersection *ref_next;
+
+ /* This is used to keep track of all the allocated
+ ref_intersection objects, so we can free them.
+ FIXME: we should allocate these in chunks. */
+ ref_intersection *alloc_next;
+};
+
+static ref_intersection *
+make_ref (void)
+{
+ ref_intersection *new_ref =
+ (ref_intersection *) vfy_alloc (sizeof (ref_intersection));
+
+ new_ref->alloc_next = vfr->isect_list;
+ vfr->isect_list = new_ref;
+ return new_ref;
+}
+
+static ref_intersection *
+clone_ref (ref_intersection *dup)
+{
+ ref_intersection *new_ref = make_ref ();
+
+ new_ref->is_resolved = dup->is_resolved;
+ new_ref->data = dup->data;
+ return new_ref;
+}
+
+static void
+resolve_ref (ref_intersection *ref)
+{
+ if (ref->is_resolved)
+ return;
+ ref->data.klass = vfy_find_class (vfr->current_class, ref->data.name);
+ ref->is_resolved = true;
+}
+
+static bool
+refs_equal (ref_intersection *ref1, ref_intersection *ref2)
+{
+ if (! ref1->is_resolved && ! ref2->is_resolved
+ && vfy_strings_equal (ref1->data.name, ref2->data.name))
+ return true;
+ if (! ref1->is_resolved)
+ resolve_ref (ref1);
+ if (! ref2->is_resolved)
+ resolve_ref (ref2);
+ return ref1->data.klass == ref2->data.klass;
+}
+
+/* Merge REF1 type into REF2, returning the result. This will
+ return REF2 if all the classes in THIS already appear in
+ REF2. */
+static ref_intersection *
+merge_refs (ref_intersection *ref1, ref_intersection *ref2)
+{
+ ref_intersection *tail = ref2;
+ for (; ref1 != NULL; ref1 = ref1->ref_next)
+ {
+ bool add = true;
+ ref_intersection *iter;
+ for (iter = ref2; iter != NULL; iter = iter->ref_next)
+ {
+ if (refs_equal (ref1, iter))
+ {
+ add = false;
+ break;
+ }
+ }
+
+ if (add)
+ {
+ ref_intersection *new_tail = clone_ref (ref1);
+ new_tail->ref_next = tail;
+ tail = new_tail;
+ }
+ }
+ return tail;
+}
+
+/* See if an object of type SOURCE can be assigned to an object of
+ type TARGET. This might resolve classes in one chain or the other. */
+static bool
+ref_compatible (ref_intersection *target, ref_intersection *source)
+{
+ for (; target != NULL; target = target->ref_next)
+ {
+ ref_intersection *source_iter = source;
+
+ for (; source_iter != NULL; source_iter = source_iter->ref_next)
+ {
+ /* Avoid resolving if possible. */
+ if (! target->is_resolved
+ && ! source_iter->is_resolved
+ && vfy_strings_equal (target->data.name,
+ source_iter->data.name))
+ continue;
+
+ if (! target->is_resolved)
+ resolve_ref (target);
+ if (! source_iter->is_resolved)
+ resolve_ref (source_iter);
+
+ if (! vfy_is_assignable_from (target->data.klass,
+ source_iter->data.klass))
+ return false;
+ }
+ }
+
+ return true;
+}
+
+static bool
+ref_isarray (ref_intersection *ref)
+{
+ /* assert (ref_next == NULL); */
+ if (ref->is_resolved)
+ return vfy_is_array (ref->data.klass);
+ else
+ return vfy_string_bytes (ref->data.name)[0] == '[';
+}
+
+static bool
+ref_isinterface (ref_intersection *ref)
+{
+ /* assert (ref_next == NULL); */
+ if (! ref->is_resolved)
+ resolve_ref (ref);
+ return vfy_is_interface (ref->data.klass);
+}
+
+static bool
+ref_isabstract (ref_intersection *ref)
+{
+ /* assert (ref_next == NULL); */
+ if (! ref->is_resolved)
+ resolve_ref (ref);
+ return vfy_is_abstract (ref->data.klass);
+}
+
+static vfy_jclass
+ref_getclass (ref_intersection *ref)
+{
+ if (! ref->is_resolved)
+ resolve_ref (ref);
+ return ref->data.klass;
+}
+
+int
+ref_count_dimensions (ref_intersection *ref)
+{
+ int ndims = 0;
+ if (ref->is_resolved)
+ {
+ vfy_jclass k = ref->data.klass;
+ while (vfy_is_array (k))
+ {
+ k = vfy_get_component_type (k);
+ ++ndims;
+ }
+ }
+ else
+ {
+ const char *p = vfy_string_bytes (ref->data.name);
+ while (*p++ == '[')
+ ++ndims;
+ }
+ return ndims;
+}
+
+/* Return the type_val corresponding to a primitive signature
+ character. For instance `I' returns `int.class'. */
+static type_val
+get_type_val_for_signature (char sig)
+{
+ type_val rt;
+ switch (sig)
+ {
+ case 'Z':
+ rt = boolean_type;
+ break;
+ case 'B':
+ rt = byte_type;
+ break;
+ case 'C':
+ rt = char_type;
+ break;
+ case 'S':
+ rt = short_type;
+ break;
+ case 'I':
+ rt = int_type;
+ break;
+ case 'J':
+ rt = long_type;
+ break;
+ case 'F':
+ rt = float_type;
+ break;
+ case 'D':
+ rt = double_type;
+ break;
+ case 'V':
+ rt = void_type;
+ break;
+ default:
+ verify_fail ("invalid signature");
+ return null_type;
+ }
+ return rt;
+}
+
+/* Return the type_val corresponding to a primitive class. */
+static type_val
+get_type_val_for_primtype (vfy_jclass k)
+{
+ return get_type_val_for_signature (vfy_get_primitive_char (k));
+}
+
+/* The `type' class is used to represent a single type in the verifier. */
+struct type
+{
+ /* The type key. */
+ type_val key;
+
+ /* For reference types, the representation of the type. */
+ ref_intersection *klass;
+
+ /* This is used in two situations.
+
+ First, when constructing a new object, it is the PC of the
+ `new' instruction which created the object. We use the special
+ value UNINIT to mean that this is uninitialized. The special
+ value SELF is used for the case where the current method is
+ itself the <init> method. the special value EITHER is used
+ when we may optionally allow either an uninitialized or
+ initialized reference to match.
+
+ Second, when the key is return_address_type, this holds the PC
+ of the instruction following the `jsr'. */
+ int pc;
+
+#define UNINIT -2
+#define SELF -1
+#define EITHER -3
+};
+
+/* Make a new instance given the type tag. We assume a generic
+ `reference_type' means Object. */
+static void
+init_type_from_tag (type *t, type_val k)
+{
+ t->key = k;
+ /* For reference_type, if KLASS==NULL then that means we are
+ looking for a generic object of any kind, including an
+ uninitialized reference. */
+ t->klass = NULL;
+ t->pc = UNINIT;
+}
+
+/* Make a type for the given type_val tag K. */
+static type
+make_type (type_val k)
+{
+ type t;
+ init_type_from_tag (&t, k);
+ return t;
+}
+
+/* Make a new instance given a class. */
+static void
+init_type_from_class (type *t, vfy_jclass k)
+{
+ t->key = reference_type;
+ t->klass = make_ref ();
+ t->klass->is_resolved = true;
+ t->klass->data.klass = k;
+ t->klass->ref_next = NULL;
+ t->pc = UNINIT;
+}
+
+static type
+make_type_from_class (vfy_jclass k)
+{
+ type t;
+ init_type_from_class (&t, k);
+ return t;
+}
+
+static void
+init_type_from_string (type *t, vfy_string n)
+{
+ t->key = reference_type;
+ t->klass = make_ref ();
+ t->klass->is_resolved = false;
+ t->klass->data.name = n;
+ t->klass->ref_next = NULL;
+ t->pc = UNINIT;
+}
+
+static type
+make_type_from_string (vfy_string n)
+{
+ type t;
+ init_type_from_string (&t, n);
+ return t;
+}
+
+/* Promote a numeric type. */
+static void
+vfy_promote_type (type *t)
+{
+ if (t->key == boolean_type || t->key == char_type
+ || t->key == byte_type || t->key == short_type)
+ t->key = int_type;
+}
+#define promote_type vfy_promote_type
+
+/* Mark this type as the uninitialized result of `new'. */
+static void
+type_set_uninitialized (type *t, int npc)
+{
+ if (t->key == reference_type)
+ t->key = uninitialized_reference_type;
+ else
+ verify_fail ("internal error in type::uninitialized");
+ t->pc = npc;
+}
+
+/* Mark this type as now initialized. */
+static void
+type_set_initialized (type *t, int npc)
+{
+ if (npc != UNINIT && t->pc == npc && t->key == uninitialized_reference_type)
+ {
+ t->key = reference_type;
+ t->pc = UNINIT;
+ }
+}
+
+/* Mark this type as a particular return address. */
+static void type_set_return_address (type *t, int npc)
+{
+ t->pc = npc;
+}
+
+/* Return true if this type and type OTHER are considered
+ mergeable for the purposes of state merging. This is related
+ to subroutine handling. For this purpose two types are
+ considered unmergeable if they are both return-addresses but
+ have different PCs. */
+static bool
+type_state_mergeable_p (type *t1, type *t2)
+{
+ return (t1->key != return_address_type
+ || t2->key != return_address_type
+ || t1->pc == t2->pc);
+}
+
+/* Return true if an object of type K can be assigned to a variable
+ of type T. Handle various special cases too. Might modify
+ T or K. Note however that this does not perform numeric
+ promotion. */
+static bool
+types_compatible (type *t, type *k)
+{
+ /* Any type is compatible with the unsuitable type. */
+ if (k->key == unsuitable_type)
+ return true;
+
+ if (t->key < reference_type || k->key < reference_type)
+ return t->key == k->key;
+
+ /* The `null' type is convertible to any initialized reference
+ type. */
+ if (t->key == null_type)
+ return k->key != uninitialized_reference_type;
+ if (k->key == null_type)
+ return t->key != uninitialized_reference_type;
+
+ /* A special case for a generic reference. */
+ if (t->klass == NULL)
+ return true;
+ if (k->klass == NULL)
+ verify_fail ("programmer error in type::compatible");
+
+ /* Handle the special 'EITHER' case, which is only used in a
+ special case of 'putfield'. Note that we only need to handle
+ this on the LHS of a check. */
+ if (! type_initialized (t) && t->pc == EITHER)
+ {
+ /* If the RHS is uninitialized, it must be an uninitialized
+ 'this'. */
+ if (! type_initialized (k) && k->pc != SELF)
+ return false;
+ }
+ else if (type_initialized (t) != type_initialized (k))
+ {
+ /* An initialized type and an uninitialized type are not
+ otherwise compatible. */
+ return false;
+ }
+ else
+ {
+ /* Two uninitialized objects are compatible if either:
+ * The PCs are identical, or
+ * One PC is UNINIT. */
+ if (type_initialized (t))
+ {
+ if (t->pc != k->pc && t->pc != UNINIT && k->pc != UNINIT)
+ return false;
+ }
+ }
+
+ return ref_compatible (t->klass, k->klass);
+}
+
+/* Return true if two types are equal. Only valid for reference
+ types. */
+static bool
+types_equal (type *t1, type *t2)
+{
+ if ((t1->key != reference_type && t1->key != uninitialized_reference_type)
+ || (t2->key != reference_type
+ && t2->key != uninitialized_reference_type))
+ return false;
+ /* Only single-ref types are allowed. */
+ if (t1->klass->ref_next || t2->klass->ref_next)
+ return false;
+ return refs_equal (t1->klass, t2->klass);
+}
+
+static bool
+type_isvoid (type *t)
+{
+ return t->key == void_type;
+}
+
+static bool
+type_iswide (type *t)
+{
+ return t->key == long_type || t->key == double_type;
+}
+
+/* Return number of stack or local variable slots taken by this type. */
+static int
+type_depth (type *t)
+{
+ return type_iswide (t) ? 2 : 1;
+}
+
+static bool
+type_isarray (type *t)
+{
+ /* We treat null_type as not an array. This is ok based on the
+ current uses of this method. */
+ if (t->key == reference_type)
+ return ref_isarray (t->klass);
+ return false;
+}
+
+static bool
+type_isnull (type *t)
+{
+ return t->key == null_type;
+}
+
+static bool
+type_isinterface (type *t)
+{
+ if (t->key != reference_type)
+ return false;
+ return ref_isinterface (t->klass);
+}
+
+static bool
+type_isabstract (type *t)
+{
+ if (t->key != reference_type)
+ return false;
+ return ref_isabstract (t->klass);
+}
+
+/* Return the element type of an array. */
+static type
+type_array_element (type *t)
+{
+ type et;
+ vfy_jclass k;
+
+ if (t->key != reference_type)
+ verify_fail ("programmer error in type::element_type()");
+
+ k = vfy_get_component_type (ref_getclass (t->klass));
+ if (vfy_is_primitive (k))
+ init_type_from_tag (&et, get_type_val_for_primtype (k));
+ else
+ init_type_from_class (&et, k);
+ return et;
+}
+
+/* Return the array type corresponding to an initialized
+ reference. We could expand this to work for other kinds of
+ types, but currently we don't need to. */
+static type
+type_to_array (type *t)
+{
+ type at;
+ vfy_jclass k;
+
+ if (t->key != reference_type)
+ verify_fail ("internal error in type::to_array()");
+
+ k = ref_getclass (t->klass);
+ init_type_from_class (&at, vfy_get_array_class (k));
+ return at;
+}
+
+static bool
+type_isreference (type *t)
+{
+ return t->key >= reference_type;
+}
+
+static int
+type_get_pc (type *t)
+{
+ return t->pc;
+}
+
+bool
+type_initialized (type *t)
+{
+ return t->key == reference_type || t->key == null_type;
+}
+
+static void
+type_verify_dimensions (type *t, int ndims)
+{
+ /* The way this is written, we don't need to check isarray(). */
+ if (t->key != reference_type)
+ verify_fail ("internal error in verify_dimensions:"
+ " not a reference type");
+
+ if (ref_count_dimensions (t->klass) < ndims)
+ verify_fail ("array type has fewer dimensions"
+ " than required");
+}
+
+/* Merge OLD_TYPE into this. On error throw exception. Return
+ true if the merge caused a type change. */
+static bool
+merge_types (type *t, type *old_type, bool local_semantics)
+{
+ bool changed = false;
+ bool refo = type_isreference (old_type);
+ bool refn = type_isreference (t);
+ if (refo && refn)
+ {
+ if (old_type->key == null_type)
+ ;
+ else if (t->key == null_type)
+ {
+ *t = *old_type;
+ changed = true;
+ }
+ else if (type_initialized (t) != type_initialized (old_type))
+ verify_fail ("merging initialized and uninitialized types");
+ else
+ {
+ ref_intersection *merged;
+ if (! type_initialized (t))
+ {
+ if (t->pc == UNINIT)
+ t->pc = old_type->pc;
+ else if (old_type->pc == UNINIT)
+ ;
+ else if (t->pc != old_type->pc)
+ verify_fail ("merging different uninitialized types");
+ }
+
+ merged = merge_refs (old_type->klass, t->klass);
+ if (merged != t->klass)
+ {
+ t->klass = merged;
+ changed = true;
+ }
+ }
+ }
+ else if (refo || refn || t->key != old_type->key)
+ {
+ if (local_semantics)
+ {
+ /* If we already have an `unsuitable' type, then we
+ don't need to change again. */
+ if (t->key != unsuitable_type)
+ {
+ t->key = unsuitable_type;
+ changed = true;
+ }
+ }
+ else
+ verify_fail ("unmergeable type");
+ }
+ return changed;
+}
+
+#ifdef VERIFY_DEBUG
+static void
+type_print (type *t)
+{
+ char c = '?';
+ switch (t->key)
+ {
+ case boolean_type: c = 'Z'; break;
+ case byte_type: c = 'B'; break;
+ case char_type: c = 'C'; break;
+ case short_type: c = 'S'; break;
+ case int_type: c = 'I'; break;
+ case long_type: c = 'J'; break;
+ case float_type: c = 'F'; break;
+ case double_type: c = 'D'; break;
+ case void_type: c = 'V'; break;
+ case unsuitable_type: c = '-'; break;
+ case return_address_type: c = 'r'; break;
+ case continuation_type: c = '+'; break;
+ case reference_type: c = 'L'; break;
+ case null_type: c = '@'; break;
+ case uninitialized_reference_type: c = 'U'; break;
+ }
+ debug_print ("%c", c);
+}
+#endif /* VERIFY_DEBUG */
+
+/* This class holds all the state information we need for a given
+ location. */
+struct state
+{
+ /* The current top of the stack, in terms of slots. */
+ int stacktop;
+ /* The current depth of the stack. This will be larger than
+ STACKTOP when wide types are on the stack. */
+ int stackdepth;
+ /* The stack. */
+ type *stack;
+ /* The local variables. */
+ type *locals;
+ /* We keep track of the type of `this' specially. This is used to
+ ensure that an instance initializer invokes another initializer
+ on `this' before returning. We must keep track of this
+ specially because otherwise we might be confused by code which
+ assigns to locals[0] (overwriting `this') and then returns
+ without really initializing. */
+ type this_type;
+
+ /* The PC for this state. This is only valid on states which are
+ permanently attached to a given PC. For an object like
+ `current_state', which is used transiently, this has no
+ meaning. */
+ int pc;
+ /* We keep a linked list of all states requiring reverification.
+ If this is the special value INVALID_STATE then this state is
+ not on the list. NULL marks the end of the linked list. */
+ state *next;
+};
+
+/* NO_NEXT is the PC value meaning that a new state must be
+ acquired from the verification list. */
+#define NO_NEXT -1
+
+static void
+init_state_with_stack (state *s, int max_stack, int max_locals)
+{
+ int i;
+ s->stacktop = 0;
+ s->stackdepth = 0;
+ s->stack = (type *) vfy_alloc (max_stack * sizeof (type));
+ for (i = 0; i < max_stack; ++i)
+ init_type_from_tag (&s->stack[i], unsuitable_type);
+ s->locals = (type *) vfy_alloc (max_locals * sizeof (type));
+ for (i = 0; i < max_locals; ++i)
+ init_type_from_tag (&s->locals[i], unsuitable_type);
+ init_type_from_tag (&s->this_type, unsuitable_type);
+ s->pc = NO_NEXT;
+ s->next = INVALID_STATE;
+}
+
+static void
+copy_state (state *s, state *copy, int max_stack, int max_locals)
+{
+ int i;
+ s->stacktop = copy->stacktop;
+ s->stackdepth = copy->stackdepth;
+ for (i = 0; i < max_stack; ++i)
+ s->stack[i] = copy->stack[i];
+ for (i = 0; i < max_locals; ++i)
+ s->locals[i] = copy->locals[i];
+
+ s->this_type = copy->this_type;
+ /* Don't modify `next' or `pc'. */
+}
+
+static void
+copy_state_with_stack (state *s, state *orig, int max_stack, int max_locals)
+{
+ init_state_with_stack (s, max_stack, max_locals);
+ copy_state (s, orig, max_stack, max_locals);
+}
+
+/* Allocate a new state, copying ORIG. */
+static state *
+make_state_copy (state *orig, int max_stack, int max_locals)
+{
+ state *s = (state *) vfy_alloc (sizeof (state));
+ copy_state_with_stack (s, orig, max_stack, max_locals);
+ return s;
+}
+
+static state *
+make_state (int max_stack, int max_locals)
+{
+ state *s = (state *) vfy_alloc (sizeof (state));
+ init_state_with_stack (s, max_stack, max_locals);
+ return s;
+}
+
+static void
+free_state (state *s)
+{
+ if (s->stack != NULL)
+ vfy_free (s->stack);
+ if (s->locals != NULL)
+ vfy_free (s->locals);
+}
+
+/* Modify this state to reflect entry to an exception handler. */
+static void
+state_set_exception (state *s, type *t, int max_stack)
+{
+ int i;
+ s->stackdepth = 1;
+ s->stacktop = 1;
+ s->stack[0] = *t;
+ for (i = s->stacktop; i < max_stack; ++i)
+ init_type_from_tag (&s->stack[i], unsuitable_type);
+}
+
+/* Merge STATE_OLD into this state. Destructively modifies this
+ state. Returns true if the new state was in fact changed.
+ Will throw an exception if the states are not mergeable. */
+static bool
+merge_states (state *s, state *state_old, int max_locals)
+{
+ int i;
+ bool changed = false;
+
+ /* Special handling for `this'. If one or the other is
+ uninitialized, then the merge is uninitialized. */
+ if (type_initialized (&s->this_type))
+ s->this_type = state_old->this_type;
+
+ /* Merge stacks. */
+ if (state_old->stacktop != s->stacktop) /* FIXME stackdepth instead? */
+ verify_fail ("stack sizes differ");
+ for (i = 0; i < state_old->stacktop; ++i)
+ {
+ if (merge_types (&s->stack[i], &state_old->stack[i], false))
+ changed = true;
+ }
+
+ /* Merge local variables. */
+ for (i = 0; i < max_locals; ++i)
+ {
+ if (merge_types (&s->locals[i], &state_old->locals[i], true))
+ changed = true;
+ }
+
+ return changed;
+}
+
+/* Ensure that `this' has been initialized. */
+static void
+state_check_this_initialized (state *s)
+{
+ if (type_isreference (&s->this_type) && ! type_initialized (&s->this_type))
+ verify_fail ("`this' is uninitialized");
+}
+
+/* Set type of `this'. */
+static void
+state_set_this_type (state *s, type *k)
+{
+ s->this_type = *k;
+}
+
+/* Mark each `new'd object we know of that was allocated at PC as
+ initialized. */
+static void
+state_set_initialized (state *s, int pc, int max_locals)
+{
+ int i;
+ for (i = 0; i < s->stacktop; ++i)
+ type_set_initialized (&s->stack[i], pc);
+ for (i = 0; i < max_locals; ++i)
+ type_set_initialized (&s->locals[i], pc);
+ type_set_initialized (&s->this_type, pc);
+}
+
+/* This tests to see whether two states can be considered "merge
+ compatible". If both states have a return-address in the same
+ slot, and the return addresses are different, then they are not
+ compatible and we must not try to merge them. */
+static bool
+state_mergeable_p (state *s, state *other, int max_locals)
+
+{
+ int i;
+
+ /* This is tricky: if the stack sizes differ, then not only are
+ these not mergeable, but in fact we should give an error, as
+ we've found two execution paths that reach a branch target
+ with different stack depths. FIXME stackdepth instead? */
+ if (s->stacktop != other->stacktop)
+ verify_fail ("stack sizes differ");
+
+ for (i = 0; i < s->stacktop; ++i)
+ if (! type_state_mergeable_p (&s->stack[i], &other->stack[i]))
+ return false;
+ for (i = 0; i < max_locals; ++i)
+ if (! type_state_mergeable_p (&s->locals[i], &other->locals[i]))
+ return false;
+ return true;
+}
+
+static void
+state_reverify (state *s)
+{
+ if (s->next == INVALID_STATE)
+ {
+ s->next = vfr->next_verify_state;
+ vfr->next_verify_state = s;
+ }
+}
+
+#ifdef VERIFY_DEBUG
+static void
+debug_print_state (state *s, const char *leader, int pc, int max_stack,
+ int max_locals)
+{
+ int i;
+ debug_print ("%s [%4d]: [stack] ", leader, pc);
+ for (i = 0; i < s->stacktop; ++i)
+ type_print (&s->stack[i]);
+ for (; i < max_stack; ++i)
+ debug_print (".");
+ debug_print (" [local] ");
+ for (i = 0; i < max_locals; ++i)
+ type_print (&s->locals[i]);
+ debug_print (" | %p\n", s);
+}
+#else
+static void
+debug_print_state (state *s ATTRIBUTE_UNUSED,
+ const char *leader ATTRIBUTE_UNUSED,
+ int pc ATTRIBUTE_UNUSED, int max_stack ATTRIBUTE_UNUSED,
+ int max_locals ATTRIBUTE_UNUSED)
+{
+}
+#endif /* VERIFY_DEBUG */
+
+static type
+pop_raw (void)
+{
+ type r;
+ state *s = vfr->current_state;
+ if (s->stacktop <= 0)
+ verify_fail ("stack empty");
+ r = s->stack[--s->stacktop];
+ s->stackdepth -= type_depth (&r);
+ if (s->stackdepth < 0)
+ verify_fail_pc ("stack empty", vfr->start_PC);
+ return r;
+}
+
+static type
+pop32 (void)
+{
+ type r = pop_raw ();
+ if (type_iswide (&r))
+ verify_fail ("narrow pop of wide type");
+ return r;
+}
+
+static type
+vfy_pop_type_t (type match)
+{
+ type t;
+ vfy_promote_type (&match);
+ t = pop_raw ();
+ if (! types_compatible (&match, &t))
+ verify_fail ("incompatible type on stack");
+ return t;
+}
+
+static type
+vfy_pop_type (type_val match)
+{
+ type t = make_type (match);
+ return vfy_pop_type_t (t);
+}
+
+#define pop_type vfy_pop_type
+#define pop_type_t vfy_pop_type_t
+
+/* Pop a reference which is guaranteed to be initialized. MATCH
+ doesn't have to be a reference type; in this case this acts like
+ pop_type. */
+static type
+pop_init_ref_t (type match)
+{
+ type t = pop_raw ();
+ if (type_isreference (&t) && ! type_initialized (&t))
+ verify_fail ("initialized reference required");
+ else if (! types_compatible (&match, &t))
+ verify_fail ("incompatible type on stack");
+ return t;
+}
+
+static type
+pop_init_ref (type_val match)
+{
+ type t = make_type (match);
+ return pop_init_ref_t (t);
+}
+
+/* Pop a reference type or a return address. */
+static type
+pop_ref_or_return (void)
+{
+ type t = pop_raw ();
+ if (! type_isreference (&t) && t.key != return_address_type)
+ verify_fail ("expected reference or return address on stack");
+ return t;
+}
+
+static void
+vfy_push_type_t (type t)
+{
+ int depth;
+ state *s = vfr->current_state;
+ /* If T is a numeric type like short, promote it to int. */
+ promote_type (&t);
+
+ depth = type_depth (&t);
+
+ if (s->stackdepth + depth > vfr->current_method->max_stack)
+ verify_fail ("stack overflow");
+ s->stack[s->stacktop++] = t;
+ s->stackdepth += depth;
+}
+
+static void
+vfy_push_type (type_val tval)
+{
+ type t = make_type (tval);
+ vfy_push_type_t (t);
+}
+
+#define push_type vfy_push_type
+#define push_type_t vfy_push_type_t
+
+static void
+set_variable (int index, type t)
+{
+ int depth;
+ state *s = vfr->current_state;
+ /* If T is a numeric type like short, promote it to int. */
+ promote_type (&t);
+
+ depth = type_depth (&t);
+ if (index > vfr->current_method->max_locals - depth)
+ verify_fail ("invalid local variable");
+ s->locals[index] = t;
+
+ if (depth == 2)
+ init_type_from_tag (&s->locals[index + 1], continuation_type);
+ if (index > 0 && type_iswide (&s->locals[index - 1]))
+ init_type_from_tag (&s->locals[index - 1], unsuitable_type);
+}
+
+static type
+get_variable_t (int index, type *t)
+{
+ state *s = vfr->current_state;
+ int depth = type_depth (t);
+ if (index > vfr->current_method->max_locals - depth)
+ verify_fail ("invalid local variable");
+ if (! types_compatible (t, &s->locals[index]))
+ verify_fail ("incompatible type in local variable");
+ if (depth == 2)
+ {
+ type cont = make_type (continuation_type);
+ if (! types_compatible (&s->locals[index + 1], &cont))
+ verify_fail ("invalid local variable");
+ }
+ return s->locals[index];
+}
+
+static type
+get_variable (int index, type_val v)
+{
+ type t = make_type (v);
+ return get_variable_t (index, &t);
+}
+
+/* Make sure ARRAY is an array type and that its elements are
+ compatible with type ELEMENT. Returns the actual element type. */
+static type
+require_array_type_t (type array, type element)
+{
+ type t;
+ /* An odd case. Here we just pretend that everything went ok. If
+ the requested element type is some kind of reference, return
+ the null type instead. */
+ if (type_isnull (&array))
+ return type_isreference (&element) ? make_type (null_type) : element;
+
+ if (! type_isarray (&array))
+ verify_fail ("array required");
+
+ t = type_array_element (&array);
+ if (! types_compatible (&element, &t))
+ {
+ /* Special case for byte arrays, which must also be boolean
+ arrays. */
+ bool ok = true;
+ if (element.key == byte_type)
+ {
+ type e2 = make_type (boolean_type);
+ ok = types_compatible (&e2, &t);
+ }
+ if (! ok)
+ verify_fail ("incompatible array element type");
+ }
+
+ /* Return T and not ELEMENT, because T might be specialized. */
+ return t;
+}
+
+static type
+require_array_type (type array, type_val element)
+{
+ type t = make_type (element);
+ return require_array_type_t (array, t);
+}
+
+static jint
+get_byte (void)
+{
+ if (vfr->PC >= vfr->current_method->code_length)
+ verify_fail ("premature end of bytecode");
+ return (jint) vfr->bytecode[vfr->PC++] & 0xff;
+}
+
+static jint
+get_ushort (void)
+{
+ jint b1 = get_byte ();
+ jint b2 = get_byte ();
+ return (jint) ((b1 << 8) | b2) & 0xffff;
+}
+
+static jint
+get_short (void)
+{
+ signed char b1 = (signed char) get_byte ();
+ jint b2 = get_byte ();
+ jshort s = (b1 << 8) | b2;
+ return (jint) s;
+}
+
+static jint
+get_int (void)
+{
+ jint b1 = get_byte ();
+ jint b2 = get_byte ();
+ jint b3 = get_byte ();
+ jint b4 = get_byte ();
+ jword result = (b1 << 24) | (b2 << 16) | (b3 << 8) | b4;
+ /* In the compiler, 'jint' might have more than 32 bits, so we must
+ sign extend. */
+ return WORD_TO_INT (result);
+}
+
+static int
+compute_jump (int offset)
+{
+ int npc = vfr->start_PC + offset;
+ if (npc < 0 || npc >= vfr->current_method->code_length)
+ verify_fail_pc ("branch out of range", vfr->start_PC);
+ return npc;
+}
+
+/* Add a new state to the state list at NPC. */
+static state *
+add_new_state (int npc, state *old_state)
+{
+ state_list *nlink;
+ vfy_method *current_method = vfr->current_method;
+ state *new_state = make_state_copy (old_state, current_method->max_stack,
+ current_method->max_locals);
+ debug_print ("== New state in add_new_state\n");
+ debug_print_state (new_state, "New", npc, current_method->max_stack,
+ current_method->max_locals);
+
+ nlink = (state_list *) vfy_alloc (sizeof (state_list));
+ nlink->val = new_state;
+ nlink->next = vfr->states[npc];
+ vfr->states[npc] = nlink;
+ new_state->pc = npc;
+ return new_state;
+}
+
+/* Merge the indicated state into the state at the branch target and
+ schedule a new PC if there is a change. NPC is the PC of the
+ branch target, and FROM_STATE is the state at the source of the
+ branch. This method returns true if the destination state
+ changed and requires reverification, false otherwise. */
+static void
+merge_into (int npc, state *from_state)
+{
+ /* Iterate over all target states and merge our state into each,
+ if applicable. FIXME one improvement we could make here is
+ "state destruction". Merging a new state into an existing one
+ might cause a return_address_type to be merged to
+ unsuitable_type. In this case the resulting state may now be
+ mergeable with other states currently held in parallel at this
+ location. So in this situation we could pairwise compare and
+ reduce the number of parallel states. */
+ state_list *iter;
+ bool applicable = false;
+ for (iter = vfr->states[npc]; iter != NULL; iter = iter->next)
+ {
+ state *new_state = iter->val;
+ vfy_method *current_method = vfr->current_method;
+
+ if (state_mergeable_p (new_state, from_state,
+ current_method->max_locals))
+ {
+ bool changed;
+ applicable = true;
+
+ debug_print ("== Merge states in merge_into\n");
+ debug_print_state (from_state, "Frm", vfr->start_PC, current_method->max_stack,
+ current_method->max_locals);
+ debug_print_state (new_state, " To", npc, current_method->max_stack,
+ current_method->max_locals);
+ changed = merge_states (new_state, from_state,
+ current_method->max_locals);
+ debug_print_state (new_state, "New", npc, current_method->max_stack,
+ current_method->max_locals);
+
+ if (changed)
+ state_reverify (new_state);
+ }
+ }
+
+ if (! applicable)
+ {
+ /* Either we don't yet have a state at NPC, or we have a
+ return-address type that is in conflict with all existing
+ state. So, we need to create a new entry. */
+ state *new_state = add_new_state (npc, from_state);
+ /* A new state added in this way must always be reverified. */
+ state_reverify (new_state);
+ }
+}
+
+static void
+push_jump (int offset)
+{
+ int npc = compute_jump (offset);
+ /* According to the JVM Spec, we need to check for uninitialized
+ objects here. However, this does not actually affect type
+ safety, and the Eclipse java compiler generates code that
+ violates this constraint. */
+ merge_into (npc, vfr->current_state);
+}
+
+static void
+push_exception_jump (type t, int pc)
+{
+ state s;
+ /* According to the JVM Spec, we need to check for uninitialized
+ objects here. However, this does not actually affect type
+ safety, and the Eclipse java compiler generates code that
+ violates this constraint. */
+ copy_state_with_stack (&s, vfr->current_state,
+ vfr->current_method->max_stack,
+ vfr->current_method->max_locals);
+ if (vfr->current_method->max_stack < 1)
+ verify_fail ("stack overflow at exception handler");
+ state_set_exception (&s, &t, vfr->current_method->max_stack);
+ merge_into (pc, &s);
+ /* FIXME: leak.. need free_state or GC */
+}
+
+static state *
+pop_jump (void)
+{
+ state *new_state = vfr->next_verify_state;
+ if (new_state == INVALID_STATE)
+ verify_fail ("programmer error in pop_jump");
+ if (new_state != NULL)
+ {
+ vfr->next_verify_state = new_state->next;
+ new_state->next = INVALID_STATE;
+ }
+ return new_state;
+}
+
+static void
+invalidate_pc (void)
+{
+ vfr->PC = NO_NEXT;
+}
+
+static void
+note_branch_target (int pc)
+{
+ /* Don't check `pc <= PC', because we've advanced PC after
+ fetching the target and we haven't yet checked the next
+ instruction. */
+ if (pc < vfr->PC && ! (vfr->flags[pc] & FLAG_INSN_START))
+ verify_fail_pc ("branch not to instruction start", vfr->start_PC);
+ vfr->flags[pc] |= FLAG_BRANCH_TARGET;
+}
+
+static void
+skip_padding (void)
+{
+ while ((vfr->PC % 4) > 0)
+ if (get_byte () != 0)
+ verify_fail ("found nonzero padding byte");
+}
+
+/* Do the work for a `ret' instruction. INDEX is the index into the
+ local variables. */
+static void
+handle_ret_insn (int index)
+{
+ type ret = make_type (return_address_type);
+ type ret_addr = get_variable_t (index, &ret);
+ /* It would be nice if we could do this. However, the JVM Spec
+ doesn't say that this is what happens. It is implied that
+ reusing a return address is invalid, but there's no actual
+ prohibition against it. */
+ /* set_variable (index, unsuitable_type); */
+
+ int npc = type_get_pc (&ret_addr);
+ /* We might be returning to a `jsr' that is at the end of the
+ bytecode. This is ok if we never return from the called
+ subroutine, but if we see this here it is an error. */
+ if (npc >= vfr->current_method->code_length)
+ verify_fail ("fell off end");
+
+ /* According to the JVM Spec, we need to check for uninitialized
+ objects here. However, this does not actually affect type
+ safety, and the Eclipse java compiler generates code that
+ violates this constraint. */
+ merge_into (npc, vfr->current_state);
+ invalidate_pc ();
+}
+
+static void handle_jsr_insn (int offset)
+{
+ type ret_addr;
+ int npc = compute_jump (offset);
+
+ /* According to the JVM Spec, we need to check for uninitialized
+ objects here. However, this does not actually affect type
+ safety, and the Eclipse java compiler generates code that
+ violates this constraint. */
+
+ /* Modify our state as appropriate for entry into a subroutine. */
+ ret_addr = make_type (return_address_type);
+ type_set_return_address (&ret_addr, vfr->PC);
+ vfy_push_type_t (ret_addr);
+ merge_into (npc, vfr->current_state);
+ invalidate_pc ();
+}
+
+static vfy_jclass
+construct_primitive_array_type (type_val prim)
+{
+ vfy_jclass k = NULL;
+ switch (prim)
+ {
+ case boolean_type:
+ case char_type:
+ case float_type:
+ case double_type:
+ case byte_type:
+ case short_type:
+ case int_type:
+ case long_type:
+ k = vfy_get_primitive_type ((int) prim);
+ break;
+
+ /* These aren't used here but we call them out to avoid
+ warnings. */
+ case void_type:
+ case unsuitable_type:
+ case return_address_type:
+ case continuation_type:
+ case reference_type:
+ case null_type:
+ case uninitialized_reference_type:
+ default:
+ verify_fail ("unknown type in construct_primitive_array_type");
+ }
+ k = vfy_get_array_class (k);
+ return k;
+}
+
+/* This pass computes the location of branch targets and also
+ instruction starts. */
+static void
+branch_prepass (void)
+{
+ int i, pc;
+ vfr->flags = (char *) vfy_alloc (vfr->current_method->code_length);
+
+ for (i = 0; i < vfr->current_method->code_length; ++i)
+ vfr->flags[i] = 0;
+
+ vfr->PC = 0;
+ while (vfr->PC < vfr->current_method->code_length)
+ {
+ java_opcode opcode;
+ /* Set `start_PC' early so that error checking can have the
+ correct value. */
+ vfr->start_PC = vfr->PC;
+ vfr->flags[vfr->PC] |= FLAG_INSN_START;
+
+ opcode = (java_opcode) vfr->bytecode[vfr->PC++];
+ switch (opcode)
+ {
+ case op_nop:
+ case op_aconst_null:
+ case op_iconst_m1:
+ case op_iconst_0:
+ case op_iconst_1:
+ case op_iconst_2:
+ case op_iconst_3:
+ case op_iconst_4:
+ case op_iconst_5:
+ case op_lconst_0:
+ case op_lconst_1:
+ case op_fconst_0:
+ case op_fconst_1:
+ case op_fconst_2:
+ case op_dconst_0:
+ case op_dconst_1:
+ case op_iload_0:
+ case op_iload_1:
+ case op_iload_2:
+ case op_iload_3:
+ case op_lload_0:
+ case op_lload_1:
+ case op_lload_2:
+ case op_lload_3:
+ case op_fload_0:
+ case op_fload_1:
+ case op_fload_2:
+ case op_fload_3:
+ case op_dload_0:
+ case op_dload_1:
+ case op_dload_2:
+ case op_dload_3:
+ case op_aload_0:
+ case op_aload_1:
+ case op_aload_2:
+ case op_aload_3:
+ case op_iaload:
+ case op_laload:
+ case op_faload:
+ case op_daload:
+ case op_aaload:
+ case op_baload:
+ case op_caload:
+ case op_saload:
+ case op_istore_0:
+ case op_istore_1:
+ case op_istore_2:
+ case op_istore_3:
+ case op_lstore_0:
+ case op_lstore_1:
+ case op_lstore_2:
+ case op_lstore_3:
+ case op_fstore_0:
+ case op_fstore_1:
+ case op_fstore_2:
+ case op_fstore_3:
+ case op_dstore_0:
+ case op_dstore_1:
+ case op_dstore_2:
+ case op_dstore_3:
+ case op_astore_0:
+ case op_astore_1:
+ case op_astore_2:
+ case op_astore_3:
+ case op_iastore:
+ case op_lastore:
+ case op_fastore:
+ case op_dastore:
+ case op_aastore:
+ case op_bastore:
+ case op_castore:
+ case op_sastore:
+ case op_pop:
+ case op_pop2:
+ case op_dup:
+ case op_dup_x1:
+ case op_dup_x2:
+ case op_dup2:
+ case op_dup2_x1:
+ case op_dup2_x2:
+ case op_swap:
+ case op_iadd:
+ case op_isub:
+ case op_imul:
+ case op_idiv:
+ case op_irem:
+ case op_ishl:
+ case op_ishr:
+ case op_iushr:
+ case op_iand:
+ case op_ior:
+ case op_ixor:
+ case op_ladd:
+ case op_lsub:
+ case op_lmul:
+ case op_ldiv:
+ case op_lrem:
+ case op_lshl:
+ case op_lshr:
+ case op_lushr:
+ case op_land:
+ case op_lor:
+ case op_lxor:
+ case op_fadd:
+ case op_fsub:
+ case op_fmul:
+ case op_fdiv:
+ case op_frem:
+ case op_dadd:
+ case op_dsub:
+ case op_dmul:
+ case op_ddiv:
+ case op_drem:
+ case op_ineg:
+ case op_i2b:
+ case op_i2c:
+ case op_i2s:
+ case op_lneg:
+ case op_fneg:
+ case op_dneg:
+ case op_i2l:
+ case op_i2f:
+ case op_i2d:
+ case op_l2i:
+ case op_l2f:
+ case op_l2d:
+ case op_f2i:
+ case op_f2l:
+ case op_f2d:
+ case op_d2i:
+ case op_d2l:
+ case op_d2f:
+ case op_lcmp:
+ case op_fcmpl:
+ case op_fcmpg:
+ case op_dcmpl:
+ case op_dcmpg:
+ case op_monitorenter:
+ case op_monitorexit:
+ case op_ireturn:
+ case op_lreturn:
+ case op_freturn:
+ case op_dreturn:
+ case op_areturn:
+ case op_return:
+ case op_athrow:
+ case op_arraylength:
+ break;
+
+ case op_bipush:
+ case op_ldc:
+ case op_iload:
+ case op_lload:
+ case op_fload:
+ case op_dload:
+ case op_aload:
+ case op_istore:
+ case op_lstore:
+ case op_fstore:
+ case op_dstore:
+ case op_astore:
+ case op_ret:
+ case op_newarray:
+ get_byte ();
+ break;
+
+ case op_iinc:
+ case op_sipush:
+ case op_ldc_w:
+ case op_ldc2_w:
+ case op_getstatic:
+ case op_getfield:
+ case op_putfield:
+ case op_putstatic:
+ case op_new:
+ case op_anewarray:
+ case op_instanceof:
+ case op_checkcast:
+ case op_invokespecial:
+ case op_invokestatic:
+ case op_invokevirtual:
+ get_short ();
+ break;
+
+ case op_multianewarray:
+ get_short ();
+ get_byte ();
+ break;
+
+ case op_jsr:
+ case op_ifeq:
+ case op_ifne:
+ case op_iflt:
+ case op_ifge:
+ case op_ifgt:
+ case op_ifle:
+ case op_if_icmpeq:
+ case op_if_icmpne:
+ case op_if_icmplt:
+ case op_if_icmpge:
+ case op_if_icmpgt:
+ case op_if_icmple:
+ case op_if_acmpeq:
+ case op_if_acmpne:
+ case op_ifnull:
+ case op_ifnonnull:
+ case op_goto:
+ note_branch_target (compute_jump (get_short ()));
+ break;
+
+ case op_tableswitch:
+ {
+ jint low, hi;
+ skip_padding ();
+ note_branch_target (compute_jump (get_int ()));
+ low = get_int ();
+ hi = get_int ();
+ if (low > hi)
+ verify_fail_pc ("invalid tableswitch", vfr->start_PC);
+ for (i = low; i <= hi; ++i)
+ note_branch_target (compute_jump (get_int ()));
+ }
+ break;
+
+ case op_lookupswitch:
+ {
+ int npairs;
+ skip_padding ();
+ note_branch_target (compute_jump (get_int ()));
+ npairs = get_int ();
+ if (npairs < 0)
+ verify_fail_pc ("too few pairs in lookupswitch", vfr->start_PC);
+ while (npairs-- > 0)
+ {
+ get_int ();
+ note_branch_target (compute_jump (get_int ()));
+ }
+ }
+ break;
+
+ case op_invokeinterface:
+ get_short ();
+ get_byte ();
+ get_byte ();
+ break;
+
+ case op_wide:
+ {
+ opcode = (java_opcode) get_byte ();
+ get_short ();
+ if (opcode == op_iinc)
+ get_short ();
+ }
+ break;
+
+ case op_jsr_w:
+ case op_goto_w:
+ note_branch_target (compute_jump (get_int ()));
+ break;
+
+#if 0
+ /* These are unused here, but we call them out explicitly
+ so that -Wswitch-enum doesn't complain. */
+ case op_putfield_1:
+ case op_putfield_2:
+ case op_putfield_4:
+ case op_putfield_8:
+ case op_putfield_a:
+ case op_putstatic_1:
+ case op_putstatic_2:
+ case op_putstatic_4:
+ case op_putstatic_8:
+ case op_putstatic_a:
+ case op_getfield_1:
+ case op_getfield_2s:
+ case op_getfield_2u:
+ case op_getfield_4:
+ case op_getfield_8:
+ case op_getfield_a:
+ case op_getstatic_1:
+ case op_getstatic_2s:
+ case op_getstatic_2u:
+ case op_getstatic_4:
+ case op_getstatic_8:
+ case op_getstatic_a:
+#endif /* VFY_FAST_OPCODES */
+ default:
+ verify_fail_pc ("unrecognized instruction in branch_prepass",
+ vfr->start_PC);
+ }
+
+ /* See if any previous branch tried to branch to the middle of
+ this instruction. */
+ for (pc = vfr->start_PC + 1; pc < vfr->PC; ++pc)
+ {
+ if ((vfr->flags[pc] & FLAG_BRANCH_TARGET))
+ verify_fail_pc ("branch to middle of instruction", pc);
+ }
+ }
+
+ /* Verify exception handlers. */
+ for (i = 0; i < vfr->current_method->exc_count; ++i)
+ {
+ int handler, start, end, htype;
+ vfy_get_exception (vfr->exception, i, &handler, &start, &end, &htype);
+ if (! (vfr->flags[handler] & FLAG_INSN_START))
+ verify_fail_pc ("exception handler not at instruction start",
+ handler);
+ if (! (vfr->flags[start] & FLAG_INSN_START))
+ verify_fail_pc ("exception start not at instruction start", start);
+ if (end != vfr->current_method->code_length
+ && ! (vfr->flags[end] & FLAG_INSN_START))
+ verify_fail_pc ("exception end not at instruction start", end);
+
+ vfr->flags[handler] |= FLAG_BRANCH_TARGET;
+ }
+}
+
+static void
+check_pool_index (int index)
+{
+ if (index < 0 || index >= vfy_get_constants_size (vfr->current_class))
+ verify_fail_pc ("constant pool index out of range", vfr->start_PC);
+}
+
+static type
+check_class_constant (int index)
+{
+ type t = { (type_val) 0, 0, 0 };
+ vfy_constants *pool;
+
+ check_pool_index (index);
+ pool = vfy_get_constants (vfr->current_class);
+ if (vfy_tag (pool, index) == JV_CONSTANT_ResolvedClass)
+ init_type_from_class (&t, vfy_get_pool_class (pool, index));
+ else if (vfy_tag (pool, index) == JV_CONSTANT_Class)
+ init_type_from_string (&t, vfy_get_pool_string (pool, index));
+ else
+ verify_fail_pc ("expected class constant", vfr->start_PC);
+ return t;
+}
+
+static type
+check_constant (int index)
+{
+ type t = { (type_val) 0, 0, 0 };
+ vfy_constants *pool;
+
+ check_pool_index (index);
+ pool = vfy_get_constants (vfr->current_class);
+ if (vfy_tag (pool, index) == JV_CONSTANT_ResolvedString
+ || vfy_tag (pool, index) == JV_CONSTANT_String)
+ init_type_from_class (&t, vfy_string_type ());
+ else if (vfy_tag (pool, index) == JV_CONSTANT_Integer)
+ init_type_from_tag (&t, int_type);
+ else if (vfy_tag (pool, index) == JV_CONSTANT_Float)
+ init_type_from_tag (&t, float_type);
+ else if (vfy_tag (pool, index) == JV_CONSTANT_Class
+ || vfy_tag (pool, index) == JV_CONSTANT_ResolvedClass)
+ /* FIXME: should only allow this for 1.5 bytecode. */
+ init_type_from_class (&t, vfy_class_type ());
+ else
+ verify_fail_pc ("String, int, or float constant expected", vfr->start_PC);
+ return t;
+}
+
+static type
+check_wide_constant (int index)
+{
+ type t = { (type_val) 0, 0, 0 };
+ vfy_constants *pool;
+
+ check_pool_index (index);
+ pool = vfy_get_constants (vfr->current_class);
+ if (vfy_tag (pool, index) == JV_CONSTANT_Long)
+ init_type_from_tag (&t, long_type);
+ else if (vfy_tag (pool, index) == JV_CONSTANT_Double)
+ init_type_from_tag (&t, double_type);
+ else
+ verify_fail_pc ("long or double constant expected", vfr->start_PC);
+ return t;
+}
+
+/* Helper for both field and method. These are laid out the same in
+ the constant pool. */
+static type
+handle_field_or_method (int index, int expected,
+ vfy_string *name, vfy_string *fmtype)
+{
+ vfy_uint_16 class_index, name_and_type_index;
+ vfy_uint_16 name_index, desc_index;
+ vfy_constants *pool;
+
+ check_pool_index (index);
+ pool = vfy_get_constants (vfr->current_class);
+ if (vfy_tag (pool, index) != expected)
+ verify_fail_pc ("didn't see expected constant", vfr->start_PC);
+ /* Once we know we have a Fieldref or Methodref we assume that it
+ is correctly laid out in the constant pool. I think the code
+ in defineclass.cc guarantees this. */
+ vfy_load_indexes (pool, index, &class_index, &name_and_type_index);
+ vfy_load_indexes (pool, name_and_type_index, &name_index, &desc_index);
+
+ *name = vfy_get_pool_string (pool, name_index);
+ *fmtype = vfy_get_pool_string (pool, desc_index);
+
+ return check_class_constant (class_index);
+}
+
+/* Return field's type, compute class' type if requested. If
+ PUTFIELD is true, use the special 'putfield' semantics. */
+static type
+check_field_constant (int index, type *class_type, bool putfield)
+{
+ vfy_string name, field_type;
+ const char *typec;
+ type t;
+
+ type ct = handle_field_or_method (index,
+ JV_CONSTANT_Fieldref,
+ &name, &field_type);
+ if (class_type)
+ *class_type = ct;
+ typec = vfy_string_bytes (field_type);
+ if (typec[0] == '[' || typec[0] == 'L')
+ init_type_from_string (&t, field_type);
+ else
+ init_type_from_tag (&t, get_type_val_for_signature (typec[0]));
+
+ /* We have an obscure special case here: we can use `putfield' on a
+ field declared in this class, even if `this' has not yet been
+ initialized. */
+ if (putfield
+ && ! type_initialized (&vfr->current_state->this_type)
+ && vfr->current_state->this_type.pc == SELF
+ && types_equal (&vfr->current_state->this_type, &ct)
+ && vfy_class_has_field (vfr->current_class, name, field_type))
+ /* Note that we don't actually know whether we're going to match
+ against 'this' or some other object of the same type. So,
+ here we set things up so that it doesn't matter. This relies
+ on knowing what our caller is up to. */
+ type_set_uninitialized (class_type, EITHER);
+
+ return t;
+}
+
+static type
+check_method_constant (int index, bool is_interface,
+ vfy_string *method_name,
+ vfy_string *method_signature)
+{
+ return handle_field_or_method (index,
+ (is_interface
+ ? JV_CONSTANT_InterfaceMethodref
+ : JV_CONSTANT_Methodref),
+ method_name, method_signature);
+}
+
+static const char *
+get_one_type (const char *p, type *t)
+{
+ const char *start = p;
+ vfy_jclass k;
+ type_val rt;
+ char v;
+
+ int arraycount = 0;
+ while (*p == '[')
+ {
+ ++arraycount;
+ ++p;
+ }
+
+ v = *p++;
+
+ if (v == 'L')
+ {
+ vfy_string name;
+ while (*p != ';')
+ ++p;
+ ++p;
+ name = vfy_get_string (start, p - start);
+ *t = make_type_from_string (name);
+ return p;
+ }
+
+ /* Casting to jchar here is ok since we are looking at an ASCII
+ character. */
+ rt = get_type_val_for_signature (v);
+
+ if (arraycount == 0)
+ {
+ /* Callers of this function eventually push their arguments on
+ the stack. So, promote them here. */
+ type new_t = make_type (rt);
+ vfy_promote_type (&new_t);
+ *t = new_t;
+ return p;
+ }
+
+ k = construct_primitive_array_type (rt);
+ while (--arraycount > 0)
+ k = vfy_get_array_class (k);
+ *t = make_type_from_class (k);
+ return p;
+}
+
+static void
+compute_argument_types (vfy_string signature, type *types)
+{
+ int i;
+ const char *p = vfy_string_bytes (signature);
+
+ /* Skip `('. */
+ ++p;
+
+ i = 0;
+ while (*p != ')')
+ p = get_one_type (p, &types[i++]);
+}
+
+static type
+compute_return_type (vfy_string signature)
+{
+ const char *p = vfy_string_bytes (signature);
+ type t;
+ while (*p != ')')
+ ++p;
+ ++p;
+ get_one_type (p, &t);
+ return t;
+}
+
+static void
+check_return_type (type onstack)
+{
+ type rt = compute_return_type (vfy_get_signature (vfr->current_method));
+ if (! types_compatible (&rt, &onstack))
+ verify_fail ("incompatible return type");
+}
+
+/* Initialize the stack for the new method. Returns true if this
+ method is an instance initializer. */
+static bool
+initialize_stack (void)
+{
+ int arg_count, i;
+ int var = 0;
+ bool is_init = vfy_strings_equal (vfy_get_method_name (vfr->current_method),
+ vfy_init_name());
+ bool is_clinit = vfy_strings_equal (vfy_get_method_name (vfr->current_method),
+ vfy_clinit_name());
+
+ if (! vfy_is_static (vfr->current_method))
+ {
+ type kurr = make_type_from_class (vfr->current_class);
+ if (is_init)
+ {
+ type_set_uninitialized (&kurr, SELF);
+ is_init = true;
+ }
+ else if (is_clinit)
+ verify_fail ("<clinit> method must be static");
+ set_variable (0, kurr);
+ state_set_this_type (vfr->current_state, &kurr);
+ ++var;
+ }
+ else
+ {
+ if (is_init)
+ verify_fail ("<init> method must be non-static");
+ }
+
+ /* We have to handle wide arguments specially here. */
+ arg_count = vfy_count_arguments (vfy_get_signature (vfr->current_method));
+ {
+ type *arg_types = (type *) vfy_alloc (arg_count * sizeof (type));
+ compute_argument_types (vfy_get_signature (vfr->current_method), arg_types);
+ for (i = 0; i < arg_count; ++i)
+ {
+ set_variable (var, arg_types[i]);
+ ++var;
+ if (type_iswide (&arg_types[i]))
+ ++var;
+ }
+ vfy_free (arg_types);
+ }
+
+ return is_init;
+}
+
+static void
+verify_instructions_0 (void)
+{
+ int i;
+ bool this_is_init;
+
+ vfr->current_state = make_state (vfr->current_method->max_stack,
+ vfr->current_method->max_locals);
+
+ vfr->PC = 0;
+ vfr->start_PC = 0;
+
+ /* True if we are verifying an instance initializer. */
+ this_is_init = initialize_stack ();
+
+ vfr->states = (state_list **) vfy_alloc (sizeof (state_list *)
+ * vfr->current_method->code_length);
+
+ for (i = 0; i < vfr->current_method->code_length; ++i)
+ vfr->states[i] = NULL;
+
+ vfr->next_verify_state = NULL;
+
+ while (true)
+ {
+ java_opcode opcode;
+
+ /* If the PC was invalidated, get a new one from the work list. */
+ if (vfr->PC == NO_NEXT)
+ {
+ state *new_state = pop_jump ();
+ /* If it is null, we're done. */
+ if (new_state == NULL)
+ break;
+
+ vfr->PC = new_state->pc;
+ debug_print ("== State pop from pending list\n");
+ /* Set up the current state. */
+ copy_state (vfr->current_state, new_state,
+ vfr->current_method->max_stack, vfr->current_method->max_locals);
+ }
+ else
+ {
+ /* We only have to do this checking in the situation where
+ control flow falls through from the previous instruction.
+ Otherwise merging is done at the time we push the branch.
+ Note that we'll catch the off-the-end problem just
+ below. */
+ if (vfr->PC < vfr->current_method->code_length
+ && vfr->states[vfr->PC] != NULL)
+ {
+ /* We've already visited this instruction. So merge
+ the states together. It is simplest, but not most
+ efficient, to just always invalidate the PC here. */
+ merge_into (vfr->PC, vfr->current_state);
+ invalidate_pc ();
+ continue;
+ }
+ }
+
+ /* Control can't fall off the end of the bytecode. We need to
+ check this in both cases, not just the fall-through case,
+ because we don't check to see whether a `jsr' appears at
+ the end of the bytecode until we process a `ret'. */
+ if (vfr->PC >= vfr->current_method->code_length)
+ verify_fail ("fell off end");
+ vfr->flags[vfr->PC] |= FLAG_INSN_SEEN;
+
+ /* We only have to keep saved state at branch targets. If
+ we're at a branch target and the state here hasn't been set
+ yet, we set it now. You might notice that `ret' targets
+ won't necessarily have FLAG_BRANCH_TARGET set. This
+ doesn't matter, since those states will be filled in by
+ merge_into. */
+ /* Note that other parts of the compiler assume that there is a
+ label with a type map at PC=0. */
+ if (vfr->states[vfr->PC] == NULL
+ && (vfr->PC == 0 || (vfr->flags[vfr->PC] & FLAG_BRANCH_TARGET) != 0))
+ add_new_state (vfr->PC, vfr->current_state);
+
+ /* Set this before handling exceptions so that debug output is
+ sane. */
+ vfr->start_PC = vfr->PC;
+
+ /* Update states for all active exception handlers. Ordinarily
+ there are not many exception handlers. So we simply run
+ through them all. */
+ for (i = 0; i < vfr->current_method->exc_count; ++i)
+ {
+ int hpc, start, end, htype;
+ vfy_get_exception (vfr->exception, i, &hpc, &start, &end, &htype);
+ if (vfr->PC >= start && vfr->PC < end)
+ {
+ type handler = make_type_from_class (vfy_throwable_type ());
+ if (htype != 0)
+ handler = check_class_constant (htype);
+ push_exception_jump (handler, hpc);
+ }
+ }
+
+
+ debug_print_state (vfr->current_state, " ", vfr->PC,
+ vfr->current_method->max_stack,
+ vfr->current_method->max_locals);
+ opcode = (java_opcode) vfr->bytecode[vfr->PC++];
+ switch (opcode)
+ {
+ case op_nop:
+ break;
+
+ case op_aconst_null:
+ push_type (null_type);
+ break;
+
+ case op_iconst_m1:
+ case op_iconst_0:
+ case op_iconst_1:
+ case op_iconst_2:
+ case op_iconst_3:
+ case op_iconst_4:
+ case op_iconst_5:
+ push_type (int_type);
+ break;
+
+ case op_lconst_0:
+ case op_lconst_1:
+ push_type (long_type);
+ break;
+
+ case op_fconst_0:
+ case op_fconst_1:
+ case op_fconst_2:
+ push_type (float_type);
+ break;
+
+ case op_dconst_0:
+ case op_dconst_1:
+ push_type (double_type);
+ break;
+
+ case op_bipush:
+ get_byte ();
+ push_type (int_type);
+ break;
+
+ case op_sipush:
+ get_short ();
+ push_type (int_type);
+ break;
+
+ case op_ldc:
+ push_type_t (check_constant (get_byte ()));
+ break;
+ case op_ldc_w:
+ push_type_t (check_constant (get_ushort ()));
+ break;
+ case op_ldc2_w:
+ push_type_t (check_wide_constant (get_ushort ()));
+ break;
+
+ case op_iload:
+ push_type_t (get_variable (get_byte (), int_type));
+ break;
+ case op_lload:
+ push_type_t (get_variable (get_byte (), long_type));
+ break;
+ case op_fload:
+ push_type_t (get_variable (get_byte (), float_type));
+ break;
+ case op_dload:
+ push_type_t (get_variable (get_byte (), double_type));
+ break;
+ case op_aload:
+ push_type_t (get_variable (get_byte (), reference_type));
+ break;
+
+ case op_iload_0:
+ case op_iload_1:
+ case op_iload_2:
+ case op_iload_3:
+ push_type_t (get_variable (opcode - op_iload_0, int_type));
+ break;
+ case op_lload_0:
+ case op_lload_1:
+ case op_lload_2:
+ case op_lload_3:
+ push_type_t (get_variable (opcode - op_lload_0, long_type));
+ break;
+ case op_fload_0:
+ case op_fload_1:
+ case op_fload_2:
+ case op_fload_3:
+ push_type_t (get_variable (opcode - op_fload_0, float_type));
+ break;
+ case op_dload_0:
+ case op_dload_1:
+ case op_dload_2:
+ case op_dload_3:
+ push_type_t (get_variable (opcode - op_dload_0, double_type));
+ break;
+ case op_aload_0:
+ case op_aload_1:
+ case op_aload_2:
+ case op_aload_3:
+ push_type_t (get_variable (opcode - op_aload_0, reference_type));
+ break;
+ case op_iaload:
+ pop_type (int_type);
+ push_type_t (require_array_type (pop_init_ref (reference_type),
+ int_type));
+ break;
+ case op_laload:
+ pop_type (int_type);
+ push_type_t (require_array_type (pop_init_ref (reference_type),
+ long_type));
+ break;
+ case op_faload:
+ pop_type (int_type);
+ push_type_t (require_array_type (pop_init_ref (reference_type),
+ float_type));
+ break;
+ case op_daload:
+ pop_type (int_type);
+ push_type_t (require_array_type (pop_init_ref (reference_type),
+ double_type));
+ break;
+ case op_aaload:
+ pop_type (int_type);
+ push_type_t (require_array_type (pop_init_ref (reference_type),
+ reference_type));
+ break;
+ case op_baload:
+ pop_type (int_type);
+ require_array_type (pop_init_ref (reference_type), byte_type);
+ push_type (int_type);
+ break;
+ case op_caload:
+ pop_type (int_type);
+ require_array_type (pop_init_ref (reference_type), char_type);
+ push_type (int_type);
+ break;
+ case op_saload:
+ pop_type (int_type);
+ require_array_type (pop_init_ref (reference_type), short_type);
+ push_type (int_type);
+ break;
+ case op_istore:
+ set_variable (get_byte (), pop_type (int_type));
+ break;
+ case op_lstore:
+ set_variable (get_byte (), pop_type (long_type));
+ break;
+ case op_fstore:
+ set_variable (get_byte (), pop_type (float_type));
+ break;
+ case op_dstore:
+ set_variable (get_byte (), pop_type (double_type));
+ break;
+ case op_astore:
+ set_variable (get_byte (), pop_ref_or_return ());
+ break;
+ case op_istore_0:
+ case op_istore_1:
+ case op_istore_2:
+ case op_istore_3:
+ set_variable (opcode - op_istore_0, pop_type (int_type));
+ break;
+ case op_lstore_0:
+ case op_lstore_1:
+ case op_lstore_2:
+ case op_lstore_3:
+ set_variable (opcode - op_lstore_0, pop_type (long_type));
+ break;
+ case op_fstore_0:
+ case op_fstore_1:
+ case op_fstore_2:
+ case op_fstore_3:
+ set_variable (opcode - op_fstore_0, pop_type (float_type));
+ break;
+ case op_dstore_0:
+ case op_dstore_1:
+ case op_dstore_2:
+ case op_dstore_3:
+ set_variable (opcode - op_dstore_0, pop_type (double_type));
+ break;
+ case op_astore_0:
+ case op_astore_1:
+ case op_astore_2:
+ case op_astore_3:
+ set_variable (opcode - op_astore_0, pop_ref_or_return ());
+ break;
+ case op_iastore:
+ pop_type (int_type);
+ pop_type (int_type);
+ require_array_type (pop_init_ref (reference_type), int_type);
+ break;
+ case op_lastore:
+ pop_type (long_type);
+ pop_type (int_type);
+ require_array_type (pop_init_ref (reference_type), long_type);
+ break;
+ case op_fastore:
+ pop_type (float_type);
+ pop_type (int_type);
+ require_array_type (pop_init_ref (reference_type), float_type);
+ break;
+ case op_dastore:
+ pop_type (double_type);
+ pop_type (int_type);
+ require_array_type (pop_init_ref (reference_type), double_type);
+ break;
+ case op_aastore:
+ pop_type (reference_type);
+ pop_type (int_type);
+ require_array_type (pop_init_ref (reference_type), reference_type);
+ break;
+ case op_bastore:
+ pop_type (int_type);
+ pop_type (int_type);
+ require_array_type (pop_init_ref (reference_type), byte_type);
+ break;
+ case op_castore:
+ pop_type (int_type);
+ pop_type (int_type);
+ require_array_type (pop_init_ref (reference_type), char_type);
+ break;
+ case op_sastore:
+ pop_type (int_type);
+ pop_type (int_type);
+ require_array_type (pop_init_ref (reference_type), short_type);
+ break;
+ case op_pop:
+ pop32 ();
+ break;
+ case op_pop2:
+ {
+ type t = pop_raw ();
+ if (! type_iswide (&t))
+ pop32 ();
+ }
+ break;
+ case op_dup:
+ {
+ type t = pop32 ();
+ push_type_t (t);
+ push_type_t (t);
+ }
+ break;
+ case op_dup_x1:
+ {
+ type t1 = pop32 ();
+ type t2 = pop32 ();
+ push_type_t (t1);
+ push_type_t (t2);
+ push_type_t (t1);
+ }
+ break;
+ case op_dup_x2:
+ {
+ type t1 = pop32 ();
+ type t2 = pop_raw ();
+ if (! type_iswide (&t2))
+ {
+ type t3 = pop32 ();
+ push_type_t (t1);
+ push_type_t (t3);
+ }
+ else
+ push_type_t (t1);
+ push_type_t (t2);
+ push_type_t (t1);
+ }
+ break;
+ case op_dup2:
+ {
+ type t = pop_raw ();
+ if (! type_iswide (&t))
+ {
+ type t2 = pop32 ();
+ push_type_t (t2);
+ push_type_t (t);
+ push_type_t (t2);
+ }
+ else
+ push_type_t (t);
+ push_type_t (t);
+ }
+ break;
+ case op_dup2_x1:
+ {
+ type t1 = pop_raw ();
+ type t2 = pop32 ();
+ if (! type_iswide (&t1))
+ {
+ type t3 = pop32 ();
+ push_type_t (t2);
+ push_type_t (t1);
+ push_type_t (t3);
+ }
+ else
+ push_type_t (t1);
+ push_type_t (t2);
+ push_type_t (t1);
+ }
+ break;
+ case op_dup2_x2:
+ {
+ type t1 = pop_raw ();
+ if (type_iswide (&t1))
+ {
+ type t2 = pop_raw ();
+ if (type_iswide (&t2))
+ {
+ push_type_t (t1);
+ push_type_t (t2);
+ }
+ else
+ {
+ type t3 = pop32 ();
+ push_type_t (t1);
+ push_type_t (t3);
+ push_type_t (t2);
+ }
+ push_type_t (t1);
+ }
+ else
+ {
+ type t2 = pop32 ();
+ type t3 = pop_raw ();
+ if (type_iswide (&t3))
+ {
+ push_type_t (t2);
+ push_type_t (t1);
+ }
+ else
+ {
+ type t4 = pop32 ();
+ push_type_t (t2);
+ push_type_t (t1);
+ push_type_t (t4);
+ }
+ push_type_t (t3);
+ push_type_t (t2);
+ push_type_t (t1);
+ }
+ }
+ break;
+ case op_swap:
+ {
+ type t1 = pop32 ();
+ type t2 = pop32 ();
+ push_type_t (t1);
+ push_type_t (t2);
+ }
+ break;
+ case op_iadd:
+ case op_isub:
+ case op_imul:
+ case op_idiv:
+ case op_irem:
+ case op_ishl:
+ case op_ishr:
+ case op_iushr:
+ case op_iand:
+ case op_ior:
+ case op_ixor:
+ pop_type (int_type);
+ push_type_t (pop_type (int_type));
+ break;
+ case op_ladd:
+ case op_lsub:
+ case op_lmul:
+ case op_ldiv:
+ case op_lrem:
+ case op_land:
+ case op_lor:
+ case op_lxor:
+ pop_type (long_type);
+ push_type_t (pop_type (long_type));
+ break;
+ case op_lshl:
+ case op_lshr:
+ case op_lushr:
+ pop_type (int_type);
+ push_type_t (pop_type (long_type));
+ break;
+ case op_fadd:
+ case op_fsub:
+ case op_fmul:
+ case op_fdiv:
+ case op_frem:
+ pop_type (float_type);
+ push_type_t (pop_type (float_type));
+ break;
+ case op_dadd:
+ case op_dsub:
+ case op_dmul:
+ case op_ddiv:
+ case op_drem:
+ pop_type (double_type);
+ push_type_t (pop_type (double_type));
+ break;
+ case op_ineg:
+ case op_i2b:
+ case op_i2c:
+ case op_i2s:
+ push_type_t (pop_type (int_type));
+ break;
+ case op_lneg:
+ push_type_t (pop_type (long_type));
+ break;
+ case op_fneg:
+ push_type_t (pop_type (float_type));
+ break;
+ case op_dneg:
+ push_type_t (pop_type (double_type));
+ break;
+ case op_iinc:
+ get_variable (get_byte (), int_type);
+ get_byte ();
+ break;
+ case op_i2l:
+ pop_type (int_type);
+ push_type (long_type);
+ break;
+ case op_i2f:
+ pop_type (int_type);
+ push_type (float_type);
+ break;
+ case op_i2d:
+ pop_type (int_type);
+ push_type (double_type);
+ break;
+ case op_l2i:
+ pop_type (long_type);
+ push_type (int_type);
+ break;
+ case op_l2f:
+ pop_type (long_type);
+ push_type (float_type);
+ break;
+ case op_l2d:
+ pop_type (long_type);
+ push_type (double_type);
+ break;
+ case op_f2i:
+ pop_type (float_type);
+ push_type (int_type);
+ break;
+ case op_f2l:
+ pop_type (float_type);
+ push_type (long_type);
+ break;
+ case op_f2d:
+ pop_type (float_type);
+ push_type (double_type);
+ break;
+ case op_d2i:
+ pop_type (double_type);
+ push_type (int_type);
+ break;
+ case op_d2l:
+ pop_type (double_type);
+ push_type (long_type);
+ break;
+ case op_d2f:
+ pop_type (double_type);
+ push_type (float_type);
+ break;
+ case op_lcmp:
+ pop_type (long_type);
+ pop_type (long_type);
+ push_type (int_type);
+ break;
+ case op_fcmpl:
+ case op_fcmpg:
+ pop_type (float_type);
+ pop_type (float_type);
+ push_type (int_type);
+ break;
+ case op_dcmpl:
+ case op_dcmpg:
+ pop_type (double_type);
+ pop_type (double_type);
+ push_type (int_type);
+ break;
+ case op_ifeq:
+ case op_ifne:
+ case op_iflt:
+ case op_ifge:
+ case op_ifgt:
+ case op_ifle:
+ pop_type (int_type);
+ push_jump (get_short ());
+ break;
+ case op_if_icmpeq:
+ case op_if_icmpne:
+ case op_if_icmplt:
+ case op_if_icmpge:
+ case op_if_icmpgt:
+ case op_if_icmple:
+ pop_type (int_type);
+ pop_type (int_type);
+ push_jump (get_short ());
+ break;
+ case op_if_acmpeq:
+ case op_if_acmpne:
+ pop_type (reference_type);
+ pop_type (reference_type);
+ push_jump (get_short ());
+ break;
+ case op_goto:
+ push_jump (get_short ());
+ invalidate_pc ();
+ break;
+ case op_jsr:
+ handle_jsr_insn (get_short ());
+ break;
+ case op_ret:
+ handle_ret_insn (get_byte ());
+ break;
+ case op_tableswitch:
+ {
+ int i;
+ jint low, high;
+ pop_type (int_type);
+ skip_padding ();
+ push_jump (get_int ());
+ low = get_int ();
+ high = get_int ();
+ /* Already checked LOW -vs- HIGH. */
+ for (i = low; i <= high; ++i)
+ push_jump (get_int ());
+ invalidate_pc ();
+ }
+ break;
+
+ case op_lookupswitch:
+ {
+ int i;
+ jint npairs, lastkey;
+
+ pop_type (int_type);
+ skip_padding ();
+ push_jump (get_int ());
+ npairs = get_int ();
+ /* Already checked NPAIRS >= 0. */
+ lastkey = 0;
+ for (i = 0; i < npairs; ++i)
+ {
+ jint key = get_int ();
+ if (i > 0 && key <= lastkey)
+ verify_fail_pc ("lookupswitch pairs unsorted", vfr->start_PC);
+ lastkey = key;
+ push_jump (get_int ());
+ }
+ invalidate_pc ();
+ }
+ break;
+ case op_ireturn:
+ check_return_type (pop_type (int_type));
+ invalidate_pc ();
+ break;
+ case op_lreturn:
+ check_return_type (pop_type (long_type));
+ invalidate_pc ();
+ break;
+ case op_freturn:
+ check_return_type (pop_type (float_type));
+ invalidate_pc ();
+ break;
+ case op_dreturn:
+ check_return_type (pop_type (double_type));
+ invalidate_pc ();
+ break;
+ case op_areturn:
+ check_return_type (pop_init_ref (reference_type));
+ invalidate_pc ();
+ break;
+ case op_return:
+ /* We only need to check this when the return type is void,
+ because all instance initializers return void. We also
+ need to special-case Object constructors, as they can't
+ call a superclass <init>. */
+ if (this_is_init && vfr->current_class != vfy_object_type ())
+ state_check_this_initialized (vfr->current_state);
+ check_return_type (make_type (void_type));
+ invalidate_pc ();
+ break;
+ case op_getstatic:
+ push_type_t (check_field_constant (get_ushort (), NULL, false));
+ break;
+ case op_putstatic:
+ pop_type_t (check_field_constant (get_ushort (), NULL, false));
+ break;
+ case op_getfield:
+ {
+ type klass;
+ type field = check_field_constant (get_ushort (), &klass, false);
+ pop_type_t (klass);
+ push_type_t (field);
+ }
+ break;
+ case op_putfield:
+ {
+ type klass;
+ type field = check_field_constant (get_ushort (), &klass, true);
+ pop_type_t (field);
+ pop_type_t (klass);
+ }
+ break;
+
+ case op_invokevirtual:
+ case op_invokespecial:
+ case op_invokestatic:
+ case op_invokeinterface:
+ {
+ vfy_string method_name, method_signature;
+ const char *namec;
+ int i, arg_count;
+ type rt;
+ bool is_init = false;
+
+ type class_type
+ = check_method_constant (get_ushort (),
+ opcode == op_invokeinterface,
+ &method_name,
+ &method_signature);
+ /* NARGS is only used when we're processing
+ invokeinterface. It is simplest for us to compute it
+ here and then verify it later. */
+ int nargs = 0;
+ if (opcode == op_invokeinterface)
+ {
+ nargs = get_byte ();
+ if (get_byte () != 0)
+ verify_fail ("invokeinterface dummy byte is wrong");
+ }
+
+ namec = vfy_string_bytes (method_name);
+
+ if (vfy_strings_equal (method_name, vfy_init_name()))
+ {
+ is_init = true;
+ if (opcode != op_invokespecial)
+ verify_fail ("can't invoke <init>");
+ }
+ else if (namec[0] == '<')
+ verify_fail ("can't invoke method starting with `<'");
+
+ arg_count = vfy_count_arguments (method_signature);
+ {
+ /* Pop arguments and check types. */
+ type *arg_types = (type *) vfy_alloc (arg_count * sizeof (type));
+
+ compute_argument_types (method_signature, arg_types);
+ for (i = arg_count - 1; i >= 0; --i)
+ {
+ /* This is only used for verifying the byte for
+ invokeinterface. */
+ nargs -= type_depth (&arg_types[i]);
+ pop_init_ref_t (arg_types[i]);
+ }
+
+ vfy_free (arg_types);
+ }
+
+ if (opcode == op_invokeinterface
+ && nargs != 1)
+ verify_fail ("wrong argument count for invokeinterface");
+
+ if (opcode != op_invokestatic)
+ {
+ type raw;
+ type t = class_type;
+ if (is_init)
+ {
+ /* In this case the PC doesn't matter. */
+ type_set_uninitialized (&t, UNINIT);
+ /* FIXME: check to make sure that the <init>
+ call is to the right class.
+ It must either be super or an exact class
+ match. */
+ }
+ raw = pop_raw ();
+ if (! types_compatible (&t, &raw))
+ verify_fail ("incompatible type on stack");
+
+ if (is_init)
+ state_set_initialized (vfr->current_state,
+ type_get_pc (&raw), vfr->current_method->max_locals);
+ }
+
+ rt = compute_return_type (method_signature);
+ if (! type_isvoid (&rt))
+ push_type_t (rt);
+ }
+ break;
+
+ case op_new:
+ {
+ type t = check_class_constant (get_ushort ());
+ if (type_isarray (&t) || type_isinterface (&t)
+ || type_isabstract (&t))
+ verify_fail ("type is array, interface, or abstract");
+ type_set_uninitialized (&t, vfr->start_PC);
+ push_type_t (t);
+ }
+ break;
+
+ case op_newarray:
+ {
+ int atype = get_byte ();
+ vfy_jclass k;
+ type t;
+ /* We intentionally have chosen constants to make this
+ valid. */
+ if (atype < boolean_type || atype > long_type)
+ verify_fail_pc ("type not primitive", vfr->start_PC);
+ pop_type (int_type);
+ k = construct_primitive_array_type ((type_val) atype);
+ init_type_from_class (&t, k);
+ push_type_t (t);
+ }
+ break;
+ case op_anewarray:
+ {
+ type t;
+ pop_type (int_type);
+ t = check_class_constant (get_ushort ());
+ push_type_t (type_to_array (&t));
+ }
+ break;
+ case op_arraylength:
+ {
+ type t = pop_init_ref (reference_type);
+ if (! type_isarray (&t) && ! type_isnull (&t))
+ verify_fail ("array type expected");
+ push_type (int_type);
+ }
+ break;
+ case op_athrow:
+ pop_type_t (make_type_from_class (vfy_throwable_type ()));
+ invalidate_pc ();
+ break;
+ case op_checkcast:
+ pop_init_ref (reference_type);
+ push_type_t (check_class_constant (get_ushort ()));
+ break;
+ case op_instanceof:
+ pop_init_ref (reference_type);
+ check_class_constant (get_ushort ());
+ push_type (int_type);
+ break;
+ case op_monitorenter:
+ pop_init_ref (reference_type);
+ break;
+ case op_monitorexit:
+ pop_init_ref (reference_type);
+ break;
+ case op_wide:
+ {
+ switch (get_byte ())
+ {
+ case op_iload:
+ push_type_t (get_variable (get_ushort (), int_type));
+ break;
+ case op_lload:
+ push_type_t (get_variable (get_ushort (), long_type));
+ break;
+ case op_fload:
+ push_type_t (get_variable (get_ushort (), float_type));
+ break;
+ case op_dload:
+ push_type_t (get_variable (get_ushort (), double_type));
+ break;
+ case op_aload:
+ push_type_t (get_variable (get_ushort (), reference_type));
+ break;
+ case op_istore:
+ set_variable (get_ushort (), pop_type (int_type));
+ break;
+ case op_lstore:
+ set_variable (get_ushort (), pop_type (long_type));
+ break;
+ case op_fstore:
+ set_variable (get_ushort (), pop_type (float_type));
+ break;
+ case op_dstore:
+ set_variable (get_ushort (), pop_type (double_type));
+ break;
+ case op_astore:
+ set_variable (get_ushort (), pop_init_ref (reference_type));
+ break;
+ case op_ret:
+ handle_ret_insn (get_short ());
+ break;
+ case op_iinc:
+ get_variable (get_ushort (), int_type);
+ get_short ();
+ break;
+ default:
+ verify_fail_pc ("unrecognized wide instruction", vfr->start_PC);
+ }
+ }
+ break;
+ case op_multianewarray:
+ {
+ int i;
+ type atype = check_class_constant (get_ushort ());
+ int dim = get_byte ();
+ if (dim < 1)
+ verify_fail_pc ("too few dimensions to multianewarray", vfr->start_PC);
+ type_verify_dimensions (&atype, dim);
+ for (i = 0; i < dim; ++i)
+ pop_type (int_type);
+ push_type_t (atype);
+ }
+ break;
+ case op_ifnull:
+ case op_ifnonnull:
+ pop_type (reference_type);
+ push_jump (get_short ());
+ break;
+ case op_goto_w:
+ push_jump (get_int ());
+ invalidate_pc ();
+ break;
+ case op_jsr_w:
+ handle_jsr_insn (get_int ());
+ break;
+
+ default:
+ /* Unrecognized opcode. */
+ verify_fail_pc ("unrecognized instruction in verify_instructions_0",
+ vfr->start_PC);
+ }
+ }
+}
+
+/* This turns a `type' into something suitable for use by the type map
+ in the other parts of the compiler. In particular, reference types
+ are mapped to Object, primitive types are unchanged, and other
+ types are mapped using special functions declared in verify.h. */
+static vfy_jclass
+collapse_type (type *t)
+{
+ switch (t->key)
+ {
+ case void_type:
+ case boolean_type:
+ case char_type:
+ case float_type:
+ case double_type:
+ case byte_type:
+ case short_type:
+ case int_type:
+ case long_type:
+ return vfy_get_primitive_type (t->key);
+
+ case unsuitable_type:
+ case continuation_type:
+ return vfy_unsuitable_type ();
+
+ case return_address_type:
+ return vfy_return_address_type ();
+
+ case null_type:
+ return vfy_null_type ();
+
+ case reference_type:
+ case uninitialized_reference_type:
+ return vfy_object_type ();
+ }
+
+ gcc_unreachable ();
+}
+
+static void
+verify_instructions (void)
+{
+ int i;
+
+ branch_prepass ();
+ verify_instructions_0 ();
+
+ /* Now tell the rest of the compiler about the types we've found. */
+ for (i = 0; i < vfr->current_method->code_length; ++i)
+ {
+ int j, slot;
+ struct state *curr;
+
+ if ((vfr->flags[i] & FLAG_INSN_SEEN) != 0)
+ vfy_note_instruction_seen (i);
+
+ if (! vfr->states[i])
+ continue;
+
+ curr = vfr->states[i]->val;
+ vfy_note_stack_depth (vfr->current_method, i, curr->stackdepth);
+
+ /* Tell the compiler about each local variable. */
+ for (j = 0; j < vfr->current_method->max_locals; ++j)
+ vfy_note_local_type (vfr->current_method, i, j,
+ collapse_type (&curr->locals[j]));
+ /* Tell the compiler about each stack slot. */
+ for (slot = j = 0; j < curr->stacktop; ++j, ++slot)
+ {
+ vfy_note_stack_type (vfr->current_method, i, slot,
+ collapse_type (&curr->stack[j]));
+ if (type_iswide (&curr->stack[j]))
+ {
+ ++slot;
+ vfy_note_stack_type (vfr->current_method, i, slot,
+ vfy_unsuitable_type ());
+ }
+ }
+ gcc_assert (slot == curr->stackdepth);
+ }
+}
+
+static void
+make_verifier_context (vfy_method *m)
+{
+ vfr = (verifier_context *) vfy_alloc (sizeof (struct verifier_context));
+
+ vfr->current_method = m;
+ vfr->bytecode = vfy_get_bytecode (m);
+ vfr->exception = vfy_get_exceptions (m);
+ vfr->current_class = m->defining_class;
+
+ vfr->states = NULL;
+ vfr->flags = NULL;
+ vfr->utf8_list = NULL;
+ vfr->isect_list = NULL;
+}
+
+static void
+free_verifier_context (void)
+{
+ vfy_string_list *utf8_list;
+ ref_intersection *isect_list;
+
+ if (vfr->flags)
+ vfy_free (vfr->flags);
+
+ utf8_list = vfr->utf8_list;
+ while (utf8_list != NULL)
+ {
+ vfy_string_list *n = utf8_list->next;
+ vfy_free (utf8_list);
+ utf8_list = n;
+ }
+
+ isect_list = vfr->isect_list;
+ while (isect_list != NULL)
+ {
+ ref_intersection *next = isect_list->alloc_next;
+ vfy_free (isect_list);
+ isect_list = next;
+ }
+
+ if (vfr->states != NULL)
+ {
+ int i;
+ for (i = 0; i < vfr->current_method->code_length; ++i)
+ {
+ state_list *iter = vfr->states[i];
+ while (iter != NULL)
+ {
+ state_list *next = iter->next;
+ free_state (iter->val);
+ vfy_free (iter->val);
+ vfy_free (iter);
+ iter = next;
+ }
+ }
+ vfy_free (vfr->states);
+ }
+
+ vfy_free (vfr);
+}
+
+int
+verify_method (vfy_method *meth)
+{
+ debug_print ("verify_method (%s) %i\n", vfy_string_bytes (meth->name),
+ meth->code_length);
+
+ if (vfr != NULL)
+ verify_fail ("verifier re-entered");
+
+ make_verifier_context (meth);
+ verify_instructions ();
+ free_verifier_context ();
+ vfr = NULL;
+
+ return 1;
+}