--- /dev/null
+// defineclass.cc - defining a class from .class format.
+
+/* Copyright (C) 2001 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. */
+
+// Writte by Tom Tromey <tromey@redhat.com>
+
+#include <config.h>
+
+#include <jvm.h>
+#include <gcj/cni.h>
+#include <java-insns.h>
+#include <java-interp.h>
+
+#include <java/lang/Class.h>
+#include <java/lang/VerifyError.h>
+#include <java/lang/Throwable.h>
+#include <java/lang/reflect/Modifier.h>
+
+
+// TO DO
+// * read more about when classes must be loaded
+// * there are bugs with boolean arrays?
+// * class loader madness
+// * Lots and lots of debugging and testing
+// * type representation is still ugly. look for the big switches
+// * at least one GC problem :-(
+
+
+// This is global because __attribute__ doesn't seem to work on static
+// methods.
+static void verify_fail (char *s) __attribute__ ((__noreturn__));
+
+class _Jv_BytecodeVerifier
+{
+private:
+
+ static const int FLAG_INSN_START = 1;
+ static const int FLAG_BRANCH_TARGET = 2;
+ static const int FLAG_JSR_TARGET = 4;
+
+ struct state;
+ struct type;
+ struct subr_info;
+
+ // 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;
+
+ // We store the state at branch targets, for merging. This holds
+ // such states.
+ state **states;
+
+ // We keep a linked list of all the PCs which we must reverify.
+ // The link is done using the PC values. This is the head of the
+ // list.
+ int next_verify_pc;
+
+ // We keep some flags for each instruction. The values are the
+ // FLAG_* constants defined above.
+ char *flags;
+
+ // We need to keep track of which instructions can call a given
+ // subroutine. FIXME: this is inefficient. We keep a linked list
+ // of all calling `jsr's at at each jsr target.
+ subr_info **jsr_ptrs;
+
+ // 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 bytecode itself.
+ unsigned char *bytecode;
+ // The exceptions.
+ _Jv_InterpException *exception;
+
+ // Defining class.
+ jclass current_class;
+ // This method.
+ _Jv_InterpMethod *current_method;
+
+ // 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.
+ 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,
+ continuation_type,
+
+ // Everything after `reference_type' must be a reference type.
+ reference_type,
+ null_type,
+ unresolved_reference_type,
+ uninitialized_reference_type,
+ uninitialized_unresolved_reference_type
+ };
+
+ // Return the type_val corresponding to a primitive signature
+ // character. For instance `I' returns `int.class'.
+ static type_val get_type_val_for_signature (jchar sig)
+ {
+ type_val rt;
+ switch (sig)
+ {
+ case 'Z':
+ rt = boolean_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 rt;
+ }
+
+ // Return the type_val corresponding to a primitive class.
+ static type_val get_type_val_for_signature (jclass k)
+ {
+ return get_type_val_for_signature ((jchar) k->method_count);
+ }
+
+ // This is used to keep track of which `jsr's correspond to a given
+ // jsr target.
+ struct subr_info
+ {
+ // PC of the instruction just after the jsr.
+ int pc;
+ // Link.
+ subr_info *next;
+ };
+
+ // The `type' class is used to represent a single type in the
+ // verifier.
+ struct type
+ {
+ // The type.
+ type_val key;
+ // Some associated data.
+ union
+ {
+ // For a resolved reference type, this is a pointer to the class.
+ jclass klass;
+ // For other reference types, this it the name of the class.
+ _Jv_Utf8Const *name;
+ } data;
+ // This is used when constructing a new object. It is the PC of the
+ // `new' instruction which created the object. We use the special
+ // value -2 to mean that this is uninitialized, and the special
+ // value -1 for the case where the current method is itself the
+ // <init> method.
+ int pc;
+
+ static const int UNINIT = -2;
+ static const int SELF = -1;
+
+ // Basic constructor.
+ type ()
+ {
+ key = unsuitable_type;
+ data.klass = NULL;
+ pc = UNINIT;
+ }
+
+ // Make a new instance given the type tag. We assume a generic
+ // `reference_type' means Object.
+ type (type_val k)
+ {
+ key = k;
+ data.klass = NULL;
+ if (key == reference_type)
+ data.klass = &java::lang::Object::class$;
+ pc = UNINIT;
+ }
+
+ // Make a new instance given a class.
+ type (jclass klass)
+ {
+ key = reference_type;
+ data.klass = klass;
+ pc = UNINIT;
+ }
+
+ // Make a new instance given the name of a class.
+ type (_Jv_Utf8Const *n)
+ {
+ key = unresolved_reference_type;
+ data.name = n;
+ pc = UNINIT;
+ }
+
+ // Copy constructor.
+ type (const type &t)
+ {
+ key = t.key;
+ data = t.data;
+ pc = t.pc;
+ }
+
+ // These operators are required because libgcj can't link in
+ // -lstdc++.
+ void *operator new[] (size_t bytes)
+ {
+ return _Jv_Malloc (bytes);
+ }
+
+ void operator delete[] (void *mem)
+ {
+ _Jv_Free (mem);
+ }
+
+ type& operator= (type_val k)
+ {
+ key = k;
+ data.klass = NULL;
+ pc = UNINIT;
+ return *this;
+ }
+
+ type& operator= (const type& t)
+ {
+ key = t.key;
+ data = t.data;
+ pc = t.pc;
+ return *this;
+ }
+
+ // Promote a numeric type.
+ void promote ()
+ {
+ if (key == boolean_type || key == char_type
+ || key == byte_type || key == short_type)
+ key = int_type;
+ }
+
+ // If *THIS is an unresolved reference type, resolve it.
+ void resolve ()
+ {
+ if (key != unresolved_reference_type
+ && key != uninitialized_unresolved_reference_type)
+ return;
+
+ // FIXME: class loader
+ using namespace java::lang;
+ // We might see either kind of name. Sigh.
+ if (data.name->data[0] == 'L'
+ && data.name->data[data.name->length - 1] == ';')
+ data.klass = _Jv_FindClassFromSignature (data.name->data, NULL);
+ else
+ data.klass = Class::forName (_Jv_NewStringUtf8Const (data.name),
+ false, NULL);
+ key = (key == unresolved_reference_type
+ ? reference_type
+ : uninitialized_reference_type);
+ }
+
+ // Mark this type as the uninitialized result of `new'.
+ void set_uninitialized (int pc)
+ {
+ if (key != reference_type && key != unresolved_reference_type)
+ verify_fail ("internal error in type::uninitialized");
+ key = (key == reference_type
+ ? uninitialized_reference_type
+ : uninitialized_unresolved_reference_type);
+ pc = pc;
+ }
+
+ // Mark this type as now initialized.
+ void set_initialized (int npc)
+ {
+ if (pc == npc)
+ {
+ key = (key == uninitialized_reference_type
+ ? reference_type
+ : unresolved_reference_type);
+ pc = UNINIT;
+ }
+ }
+
+
+ // Return true if an object of type K can be assigned to a variable
+ // of type *THIS. Handle various special cases too. Might modify
+ // *THIS or K. Note however that this does not perform numeric
+ // promotion.
+ bool compatible (type &k)
+ {
+ // Any type is compatible with the unsuitable type.
+ if (key == unsuitable_type)
+ return true;
+
+ if (key < reference_type || k.key < reference_type)
+ return key == k.key;
+
+ // The `null' type is convertible to any reference type.
+ // FIXME: is this correct for THIS?
+ if (key == null_type || k.key == null_type)
+ return true;
+
+ // Any reference type is convertible to Object. This is a special
+ // case so we don't need to unnecessarily resolve a class.
+ if (key == reference_type
+ && data.klass == &java::lang::Object::class$)
+ return true;
+
+ // An initialized type and an uninitialized type are not
+ // compatible.
+ if (isinitialized () != k.isinitialized ())
+ return false;
+
+ // Two uninitialized objects are compatible if either:
+ // * The PCs are identical, or
+ // * One PC is UNINIT.
+ if (! isinitialized ())
+ {
+ if (pc != k.pc && pc != UNINIT && k.pc != UNINIT)
+ return false;
+ }
+
+ // Two unresolved types are equal if their names are the same.
+ if (! isresolved ()
+ && ! k.isresolved ()
+ && _Jv_equalUtf8Consts (data.name, k.data.name))
+ return true;
+
+ // We must resolve both types and check assignability.
+ resolve ();
+ k.resolve ();
+ return data.klass->isAssignableFrom (k.data.klass);
+ }
+
+ bool isvoid () const
+ {
+ return key == void_type;
+ }
+
+ bool iswide () const
+ {
+ return key == long_type || key == double_type;
+ }
+
+ // Return number of stack or local variable slots taken by this
+ // type.
+ int depth () const
+ {
+ return iswide () ? 2 : 1;
+ }
+
+ bool isarray () const
+ {
+ // We treat null_type as not an array. This is ok based on the
+ // current uses of this method.
+ if (key == reference_type)
+ return data.klass->isArray ();
+ else if (key == unresolved_reference_type)
+ return data.name->data[0] == '[';
+ return false;
+ }
+
+ bool isinterface ()
+ {
+ resolve ();
+ if (key != reference_type)
+ return false;
+ return data.klass->isInterface ();
+ }
+
+ bool isabstract ()
+ {
+ resolve ();
+ if (key != reference_type)
+ return false;
+ using namespace java::lang::reflect;
+ return Modifier::isAbstract (data.klass->getModifiers ());
+ }
+
+ // Return the element type of an array.
+ type element_type ()
+ {
+ // FIXME: maybe should do string manipulation here.
+ resolve ();
+ if (key != reference_type)
+ verify_fail ("programmer error in type::element_type()");
+
+ jclass k = data.klass->getComponentType ();
+ if (k->isPrimitive ())
+ return type (get_type_val_for_signature (k));
+ return type (k);
+ }
+
+ bool isreference () const
+ {
+ return key >= reference_type;
+ }
+
+ int get_pc () const
+ {
+ return pc;
+ }
+
+ bool isinitialized () const
+ {
+ return (key == reference_type
+ || key == null_type
+ || key == unresolved_reference_type);
+ }
+
+ bool isresolved () const
+ {
+ return (key == reference_type
+ || key == null_type
+ || key == uninitialized_reference_type);
+ }
+
+ void verify_dimensions (int ndims)
+ {
+ // The way this is written, we don't need to check isarray().
+ if (key == reference_type)
+ {
+ jclass k = data.klass;
+ while (k->isArray () && ndims > 0)
+ {
+ k = k->getComponentType ();
+ --ndims;
+ }
+ }
+ else
+ {
+ // We know KEY == unresolved_reference_type.
+ char *p = data.name->data;
+ while (*p++ == '[' && ndims-- > 0)
+ ;
+ }
+
+ if (ndims > 0)
+ verify_fail ("array type has fewer dimensions than required");
+ }
+
+ // Merge OLD_TYPE into this. On error throw exception.
+ bool merge (type& old_type, bool local_semantics = false)
+ {
+ bool changed = false;
+ bool refo = old_type.isreference ();
+ bool refn = isreference ();
+ if (refo && refn)
+ {
+ if (old_type.key == null_type)
+ ;
+ else if (key == null_type)
+ {
+ *this = old_type;
+ changed = true;
+ }
+ else if (isinitialized () != old_type.isinitialized ())
+ verify_fail ("merging initialized and uninitialized types");
+ else
+ {
+ if (! isinitialized ())
+ {
+ if (pc == UNINIT)
+ pc = old_type.pc;
+ else if (old_type.pc == UNINIT)
+ ;
+ else if (pc != old_type.pc)
+ verify_fail ("merging different uninitialized types");
+ }
+
+ if (! isresolved ()
+ && ! old_type.isresolved ()
+ && _Jv_equalUtf8Consts (data.name, old_type.data.name))
+ {
+ // Types are identical.
+ }
+ else
+ {
+ resolve ();
+ old_type.resolve ();
+
+ jclass k = data.klass;
+ jclass oldk = old_type.data.klass;
+
+ int arraycount = 0;
+ while (k->isArray () && oldk->isArray ())
+ {
+ ++arraycount;
+ k = k->getComponentType ();
+ oldk = oldk->getComponentType ();
+ }
+
+ // This loop will end when we hit Object.
+ while (true)
+ {
+ if (k->isAssignableFrom (oldk))
+ break;
+ k = k->getSuperclass ();
+ changed = true;
+ }
+
+ if (changed)
+ {
+ while (arraycount > 0)
+ {
+ // FIXME: Class loader.
+ k = _Jv_GetArrayClass (k, NULL);
+ --arraycount;
+ }
+ data.klass = k;
+ }
+ }
+ }
+ }
+ else if (refo || refn || key != old_type.key)
+ {
+ if (local_semantics)
+ {
+ key = unsuitable_type;
+ changed = true;
+ }
+ else
+ verify_fail ("unmergeable type");
+ }
+ return changed;
+ }
+ };
+
+ // This class holds all the state information we need for a given
+ // location.
+ struct state
+ {
+ // Current top of stack.
+ int stacktop;
+ // Current stack depth. This is like the top of stack but it
+ // includes wide variable information.
+ int stackdepth;
+ // The stack.
+ type *stack;
+ // The local variables.
+ type *locals;
+ // This is used in subroutines to keep track of which local
+ // variables have been accessed.
+ bool *local_changed;
+ // If not 0, then we are in a subroutine. The value is the PC of
+ // the subroutine's entry point. We can use 0 as an exceptional
+ // value because PC=0 can never be a subroutine.
+ int subroutine;
+ // This is used to keep a linked list of all the states which
+ // require re-verification. We use the PC to keep track.
+ int next;
+
+ // INVALID marks a state which is not on the linked list of states
+ // requiring reverification.
+ static const int INVALID = -1;
+ // NO_NEXT marks the state at the end of the reverification list.
+ static const int NO_NEXT = -2;
+
+ state ()
+ {
+ stack = NULL;
+ locals = NULL;
+ local_changed = NULL;
+ }
+
+ state (int max_stack, int max_locals)
+ {
+ stacktop = 0;
+ stackdepth = 0;
+ stack = new type[max_stack];
+ for (int i = 0; i < max_stack; ++i)
+ stack[i] = unsuitable_type;
+ locals = new type[max_locals];
+ local_changed = (bool *) _Jv_Malloc (sizeof (bool) * max_locals);
+ for (int i = 0; i < max_locals; ++i)
+ {
+ locals[i] = unsuitable_type;
+ local_changed[i] = false;
+ }
+ next = INVALID;
+ subroutine = 0;
+ }
+
+ state (const state *copy, int max_stack, int max_locals)
+ {
+ stack = new type[max_stack];
+ locals = new type[max_locals];
+ local_changed = (bool *) _Jv_Malloc (sizeof (bool) * max_locals);
+ *this = *copy;
+ next = INVALID;
+ }
+
+ ~state ()
+ {
+ if (stack)
+ delete[] stack;
+ if (locals)
+ delete[] locals;
+ if (local_changed)
+ _Jv_Free (local_changed);
+ }
+
+ void *operator new[] (size_t bytes)
+ {
+ return _Jv_Malloc (bytes);
+ }
+
+ void operator delete[] (void *mem)
+ {
+ _Jv_Free (mem);
+ }
+
+ void *operator new (size_t bytes)
+ {
+ return _Jv_Malloc (bytes);
+ }
+
+ void operator delete (void *mem)
+ {
+ _Jv_Free (mem);
+ }
+
+ void copy (const state *copy, int max_stack, int max_locals)
+ {
+ stacktop = copy->stacktop;
+ stackdepth = copy->stackdepth;
+ subroutine = copy->subroutine;
+ for (int i = 0; i < max_stack; ++i)
+ stack[i] = copy->stack[i];
+ for (int i = 0; i < max_locals; ++i)
+ {
+ locals[i] = copy->locals[i];
+ local_changed[i] = copy->local_changed[i];
+ }
+ // Don't modify `next'.
+ }
+
+ // Modify this state to reflect entry to an exception handler.
+ void set_exception (type t, int max_stack)
+ {
+ stackdepth = 1;
+ stacktop = 1;
+ stack[0] = t;
+ for (int i = stacktop; i < max_stack; ++i)
+ stack[i] = unsuitable_type;
+
+ // FIXME: subroutine handling?
+ }
+
+ // Merge STATE 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.
+ bool merge (state *state_old, bool ret_semantics,
+ int max_locals)
+ {
+ bool changed = false;
+
+ // Merge subroutine states. *THIS and *STATE_OLD must be in the
+ // same subroutine. Also, recursive subroutine calls must be
+ // avoided.
+ if (subroutine == state_old->subroutine)
+ {
+ // Nothing.
+ }
+ else if (subroutine == 0)
+ {
+ subroutine = state_old->subroutine;
+ changed = true;
+ }
+ else
+ verify_fail ("subroutines merged");
+
+ // Merge stacks.
+ if (state_old->stacktop != stacktop)
+ verify_fail ("stack sizes differ");
+ for (int i = 0; i < state_old->stacktop; ++i)
+ {
+ if (stack[i].merge (state_old->stack[i]))
+ changed = true;
+ }
+
+ // Merge local variables.
+ for (int i = 0; i < max_locals; ++i)
+ {
+ if (! ret_semantics || local_changed[i])
+ {
+ if (locals[i].merge (state_old->locals[i], true))
+ {
+ changed = true;
+ note_variable (i);
+ }
+ }
+
+ // If we're in a subroutine, we must compute the union of
+ // all the changed local variables.
+ if (state_old->local_changed[i])
+ note_variable (i);
+ }
+
+ return changed;
+ }
+
+ // Throw an exception if there is an uninitialized object on the
+ // stack or in a local variable. EXCEPTION_SEMANTICS controls
+ // whether we're using backwards-branch or exception-handing
+ // semantics.
+ void check_no_uninitialized_objects (int max_locals,
+ bool exception_semantics = false)
+ {
+ if (! exception_semantics)
+ {
+ for (int i = 0; i < stacktop; ++i)
+ if (stack[i].isreference () && ! stack[i].isinitialized ())
+ verify_fail ("uninitialized object on stack");
+ }
+
+ for (int i = 0; i < max_locals; ++i)
+ if (locals[i].isreference () && ! locals[i].isinitialized ())
+ verify_fail ("uninitialized object in local variable");
+ }
+
+ // Note that a local variable was accessed or modified.
+ void note_variable (int index)
+ {
+ if (subroutine > 0)
+ local_changed[index] = true;
+ }
+
+ // Mark each `new'd object we know of that was allocated at PC as
+ // initialized.
+ void set_initialized (int pc, int max_locals)
+ {
+ for (int i = 0; i < stacktop; ++i)
+ stack[i].set_initialized (pc);
+ for (int i = 0; i < max_locals; ++i)
+ locals[i].set_initialized (pc);
+ }
+ };
+
+ type pop_raw ()
+ {
+ if (current_state->stacktop <= 0)
+ verify_fail ("stack empty");
+ type r = current_state->stack[--current_state->stacktop];
+ current_state->stackdepth -= r.depth ();
+ if (current_state->stackdepth < 0)
+ verify_fail ("stack empty");
+ return r;
+ }
+
+ type pop32 ()
+ {
+ type r = pop_raw ();
+ if (r.iswide ())
+ verify_fail ("narrow pop of wide type");
+ return r;
+ }
+
+ type pop64 ()
+ {
+ type r = pop_raw ();
+ if (! r.iswide ())
+ verify_fail ("wide pop of narrow type");
+ return r;
+ }
+
+ type pop_type (type match)
+ {
+ type t = pop_raw ();
+ if (! match.compatible (t))
+ verify_fail ("incompatible type on stack");
+ return t;
+ }
+
+ void push_type (type t)
+ {
+ // If T is a numeric type like short, promote it to int.
+ t.promote ();
+
+ int depth = t.depth ();
+ if (current_state->stackdepth + depth > current_method->max_stack)
+ verify_fail ("stack overflow");
+ current_state->stack[current_state->stacktop++] = t;
+ current_state->stackdepth += depth;
+ }
+
+ void set_variable (int index, type t)
+ {
+ // If T is a numeric type like short, promote it to int.
+ t.promote ();
+
+ int depth = t.depth ();
+ if (index > current_method->max_locals - depth)
+ verify_fail ("invalid local variable");
+ current_state->locals[index] = t;
+ current_state->note_variable (index);
+
+ if (depth == 2)
+ {
+ current_state->locals[index + 1] = continuation_type;
+ current_state->note_variable (index + 1);
+ }
+ if (index > 0 && current_state->locals[index - 1].iswide ())
+ {
+ current_state->locals[index - 1] = unsuitable_type;
+ // There's no need to call note_variable here.
+ }
+ }
+
+ type get_variable (int index, type t)
+ {
+ int depth = t.depth ();
+ if (index > current_method->max_locals - depth)
+ verify_fail ("invalid local variable");
+ if (! t.compatible (current_state->locals[index]))
+ verify_fail ("incompatible type in local variable");
+ if (depth == 2)
+ {
+ type t (continuation_type);
+ if (! current_state->locals[index + 1].compatible (t))
+ verify_fail ("invalid local variable");
+ }
+ current_state->note_variable (index);
+ return current_state->locals[index];
+ }
+
+ // Make sure ARRAY is an array type and that its elements are
+ // compatible with type ELEMENT. Returns the actual element type.
+ type require_array_type (type array, type element)
+ {
+ if (! array.isarray ())
+ verify_fail ("array required");
+
+ type t = array.element_type ();
+ if (! element.compatible (t))
+ verify_fail ("incompatible array element type");
+
+ // Return T and not ELEMENT, because T might be specialized.
+ return t;
+ }
+
+ jint get_byte ()
+ {
+ if (PC >= current_method->code_length)
+ verify_fail ("premature end of bytecode");
+ return (jint) bytecode[PC++] & 0xff;
+ }
+
+ jint get_ushort ()
+ {
+ jbyte b1 = get_byte ();
+ jbyte b2 = get_byte ();
+ return (jint) ((b1 << 8) | b2) & 0xffff;
+ }
+
+ jint get_short ()
+ {
+ jbyte b1 = get_byte ();
+ jbyte b2 = get_byte ();
+ jshort s = (b1 << 8) | b2;
+ return (jint) s;
+ }
+
+ jint get_int ()
+ {
+ jbyte b1 = get_byte ();
+ jbyte b2 = get_byte ();
+ jbyte b3 = get_byte ();
+ jbyte b4 = get_byte ();
+ return (b1 << 24) | (b2 << 16) | (b3 << 8) | b4;
+ }
+
+ int compute_jump (int offset)
+ {
+ int npc = start_PC + offset;
+ if (npc < 0 || npc >= current_method->code_length)
+ verify_fail ("branch out of range");
+ return npc;
+ }
+
+ // Merge the indicated state into a new state and schedule a new PC if
+ // there is a change. If RET_SEMANTICS is true, then we are merging
+ // from a `ret' instruction into the instruction after a `jsr'. This
+ // is a special case with its own modified semantics.
+ void push_jump_merge (int npc, state *nstate, bool ret_semantics = false)
+ {
+ bool changed = true;
+ if (states[npc] == NULL)
+ {
+ // FIXME: what if we reach this code from a `ret'?
+
+ states[npc] = new state (nstate, current_method->max_stack,
+ current_method->max_locals);
+ }
+ else
+ changed = nstate->merge (states[npc], ret_semantics,
+ current_method->max_stack);
+
+ if (changed && states[npc]->next == state::INVALID)
+ {
+ // The merge changed the state, and the new PC isn't yet on our
+ // list of PCs to re-verify.
+ states[npc]->next = next_verify_pc;
+ next_verify_pc = npc;
+ }
+ }
+
+ void push_jump (int offset)
+ {
+ int npc = compute_jump (offset);
+ if (npc < PC)
+ current_state->check_no_uninitialized_objects (current_method->max_stack);
+ push_jump_merge (npc, current_state);
+ }
+
+ void push_exception_jump (type t, int pc)
+ {
+ current_state->check_no_uninitialized_objects (current_method->max_stack,
+ true);
+ state s (current_state, current_method->max_stack,
+ current_method->max_locals);
+ s.set_exception (t, current_method->max_stack);
+ push_jump_merge (pc, &s);
+ }
+
+ int pop_jump ()
+ {
+ int npc = next_verify_pc;
+ if (npc != state::NO_NEXT)
+ {
+ next_verify_pc = states[npc]->next;
+ states[npc]->next = state::INVALID;
+ }
+ return npc;
+ }
+
+ void invalidate_pc ()
+ {
+ PC = state::NO_NEXT;
+ }
+
+ void note_branch_target (int pc, bool is_jsr_target = false)
+ {
+ if (pc <= PC && ! (flags[pc] & FLAG_INSN_START))
+ verify_fail ("branch not to instruction start");
+ flags[pc] |= FLAG_BRANCH_TARGET;
+ if (is_jsr_target)
+ {
+ // Record the jsr which called this instruction.
+ subr_info *info = (subr_info *) _Jv_Malloc (sizeof (subr_info));
+ info->pc = PC;
+ info->next = jsr_ptrs[pc];
+ jsr_ptrs[pc] = info;
+ flags[pc] |= FLAG_JSR_TARGET;
+ }
+ }
+
+ void skip_padding ()
+ {
+ while ((PC % 4) > 0)
+ get_byte ();
+ }
+
+ // Return the subroutine to which the instruction at PC belongs.
+ int get_subroutine (int pc)
+ {
+ if (states[pc] == NULL)
+ return 0;
+ return states[pc]->subroutine;
+ }
+
+ // Do the work for a `ret' instruction. INDEX is the index into the
+ // local variables.
+ void handle_ret_insn (int index)
+ {
+ get_variable (index, return_address_type);
+
+ int csub = current_state->subroutine;
+ if (csub == 0)
+ verify_fail ("no subroutine");
+
+ for (subr_info *subr = jsr_ptrs[csub]; subr != NULL; subr = subr->next)
+ {
+ // Temporarily modify the current state so it looks like we're
+ // in the enclosing context.
+ current_state->subroutine = get_subroutine (subr->pc);
+ if (subr->pc < PC)
+ current_state->check_no_uninitialized_objects (current_method->max_stack);
+ push_jump_merge (subr->pc, current_state, true);
+ }
+
+ current_state->subroutine = csub;
+ invalidate_pc ();
+ }
+
+ // We're in the subroutine SUB, calling a subroutine at DEST. Make
+ // sure this subroutine isn't already on the stack.
+ void check_nonrecursive_call (int sub, int dest)
+ {
+ if (sub == 0)
+ return;
+ if (sub == dest)
+ verify_fail ("recursive subroutine call");
+ for (subr_info *info = jsr_ptrs[sub]; info != NULL; info = info->next)
+ check_nonrecursive_call (get_subroutine (info->pc), dest);
+ }
+
+ void handle_jsr_insn (int offset)
+ {
+ int npc = compute_jump (offset);
+
+ if (npc < PC)
+ current_state->check_no_uninitialized_objects (current_method->max_stack);
+ check_nonrecursive_call (current_state->subroutine, npc);
+
+ // Temporarily modify the current state so that it looks like we are
+ // in the subroutine.
+ push_type (return_address_type);
+ int save = current_state->subroutine;
+ current_state->subroutine = npc;
+
+ // Merge into the subroutine.
+ push_jump_merge (npc, current_state);
+
+ // Undo our modifications.
+ current_state->subroutine = save;
+ pop_type (return_address_type);
+ }
+
+ jclass construct_primitive_array_type (type_val prim)
+ {
+ jclass k = NULL;
+ switch (prim)
+ {
+ case boolean_type:
+ k = JvPrimClass (boolean);
+ break;
+ case char_type:
+ k = JvPrimClass (char);
+ break;
+ case float_type:
+ k = JvPrimClass (float);
+ break;
+ case double_type:
+ k = JvPrimClass (double);
+ break;
+ case byte_type:
+ k = JvPrimClass (byte);
+ break;
+ case short_type:
+ k = JvPrimClass (short);
+ break;
+ case int_type:
+ k = JvPrimClass (int);
+ break;
+ case long_type:
+ k = JvPrimClass (long);
+ break;
+ default:
+ verify_fail ("unknown type in construct_primitive_array_type");
+ }
+ k = _Jv_GetArrayClass (k, NULL);
+ return k;
+ }
+
+ // This pass computes the location of branch targets and also
+ // instruction starts.
+ void branch_prepass ()
+ {
+ flags = (char *) _Jv_Malloc (current_method->code_length);
+ jsr_ptrs = (subr_info **) _Jv_Malloc (sizeof (subr_info *)
+ * current_method->code_length);
+
+ for (int i = 0; i < current_method->code_length; ++i)
+ {
+ flags[i] = 0;
+ jsr_ptrs[i] = NULL;
+ }
+
+ bool last_was_jsr = false;
+
+ PC = 0;
+ while (PC < current_method->code_length)
+ {
+ flags[PC] |= FLAG_INSN_START;
+
+ // If the previous instruction was a jsr, then the next
+ // instruction is a branch target -- the branch being the
+ // corresponding `ret'.
+ if (last_was_jsr)
+ note_branch_target (PC);
+ last_was_jsr = false;
+
+ start_PC = PC;
+ unsigned char opcode = bytecode[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_iinc:
+ 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:
+ break;
+
+ case op_bipush:
+ case op_sipush:
+ 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_arraylength:
+ case op_ret:
+ get_byte ();
+ break;
+
+ 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:
+ last_was_jsr = true;
+ // Fall through.
+ 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 ()), last_was_jsr);
+ break;
+
+ case op_tableswitch:
+ {
+ skip_padding ();
+ note_branch_target (compute_jump (get_int ()));
+ jint low = get_int ();
+ jint hi = get_int ();
+ if (low > hi)
+ verify_fail ("invalid tableswitch");
+ for (int i = low; i <= hi; ++i)
+ note_branch_target (compute_jump (get_int ()));
+ }
+ break;
+
+ case op_lookupswitch:
+ {
+ skip_padding ();
+ note_branch_target (compute_jump (get_int ()));
+ int npairs = get_int ();
+ if (npairs < 0)
+ verify_fail ("too few pairs in lookupswitch");
+ 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 = get_byte ();
+ get_short ();
+ if (opcode == (unsigned char) op_iinc)
+ get_short ();
+ }
+ break;
+
+ case op_jsr_w:
+ last_was_jsr = true;
+ // Fall through.
+ case op_goto_w:
+ note_branch_target (compute_jump (get_int ()), last_was_jsr);
+ break;
+
+ default:
+ verify_fail ("unrecognized instruction");
+ }
+
+ // See if any previous branch tried to branch to the middle of
+ // this instruction.
+ for (int pc = start_PC + 1; pc < PC; ++pc)
+ {
+ if ((flags[pc] & FLAG_BRANCH_TARGET))
+ verify_fail ("branch not to instruction start");
+ }
+ }
+
+ // Verify exception handlers.
+ for (int i = 0; i < current_method->exc_count; ++i)
+ {
+ if (! (flags[exception[i].handler_pc] & FLAG_INSN_START))
+ verify_fail ("exception handler not at instruction start");
+ if (exception[i].start_pc > exception[i].end_pc)
+ verify_fail ("exception range inverted");
+ if (! (flags[exception[i].start_pc] & FLAG_INSN_START)
+ || ! (flags[exception[i].start_pc] & FLAG_INSN_START))
+ verify_fail ("exception endpoint not at instruction start");
+
+ flags[exception[i].handler_pc] |= FLAG_BRANCH_TARGET;
+ }
+ }
+
+ void check_pool_index (int index)
+ {
+ if (index < 0 || index >= current_class->constants.size)
+ verify_fail ("constant pool index out of range");
+ }
+
+ type check_class_constant (int index)
+ {
+ check_pool_index (index);
+ _Jv_Constants *pool = ¤t_class->constants;
+ if (pool->tags[index] == JV_CONSTANT_ResolvedClass)
+ return type (pool->data[index].clazz);
+ else if (pool->tags[index] == JV_CONSTANT_Class)
+ return type (pool->data[index].utf8);
+ verify_fail ("expected class constant");
+ }
+
+ type check_constant (int index)
+ {
+ check_pool_index (index);
+ _Jv_Constants *pool = ¤t_class->constants;
+ if (pool->tags[index] == JV_CONSTANT_ResolvedString
+ || pool->tags[index] == JV_CONSTANT_String)
+ return type (&java::lang::String::class$);
+ else if (pool->tags[index] == JV_CONSTANT_Integer)
+ return type (int_type);
+ else if (pool->tags[index] == JV_CONSTANT_Float)
+ return type (float_type);
+ verify_fail ("String, int, or float constant expected");
+ }
+
+ // Helper for both field and method. These are laid out the same in
+ // the constant pool.
+ type handle_field_or_method (int index, int expected,
+ _Jv_Utf8Const **name,
+ _Jv_Utf8Const **fmtype)
+ {
+ check_pool_index (index);
+ _Jv_Constants *pool = ¤t_class->constants;
+ if (pool->tags[index] != expected)
+ verify_fail ("didn't see expected constant");
+ // 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.
+ _Jv_ushort class_index, name_and_type_index;
+ _Jv_loadIndexes (&pool->data[index],
+ class_index,
+ name_and_type_index);
+ _Jv_ushort name_index, desc_index;
+ _Jv_loadIndexes (&pool->data[name_and_type_index],
+ name_index, desc_index);
+
+ *name = pool->data[name_index].utf8;
+ *fmtype = pool->data[desc_index].utf8;
+
+ return check_class_constant (class_index);
+ }
+
+ // Return field's type, compute class' type if requested.
+ type check_field_constant (int index, type *class_type = NULL)
+ {
+ _Jv_Utf8Const *name, *field_type;
+ type ct = handle_field_or_method (index,
+ JV_CONSTANT_Fieldref,
+ &name, &field_type);
+ if (class_type)
+ *class_type = ct;
+ return type (field_type);
+ }
+
+ type check_method_constant (int index, bool is_interface,
+ _Jv_Utf8Const **method_name,
+ _Jv_Utf8Const **method_signature)
+ {
+ return handle_field_or_method (index,
+ (is_interface
+ ? JV_CONSTANT_InterfaceMethodref
+ : JV_CONSTANT_Methodref),
+ method_name, method_signature);
+ }
+
+ type get_one_type (char *&p)
+ {
+ char *start = p;
+
+ int arraycount = 0;
+ while (*p == '[')
+ {
+ ++arraycount;
+ ++p;
+ }
+
+ char v = *p++;
+
+ if (v == 'L')
+ {
+ while (*p != ';')
+ ++p;
+ ++p;
+ // FIXME! This will get collected!
+ _Jv_Utf8Const *name = _Jv_makeUtf8Const (start, p - start);
+ return type (name);
+ }
+
+ // Casting to jchar here is ok since we are looking at an ASCII
+ // character.
+ type_val rt = get_type_val_for_signature (jchar (v));
+
+ if (arraycount == 0)
+ return type (rt);
+
+ jclass k = construct_primitive_array_type (rt);
+ while (--arraycount > 0)
+ k = _Jv_GetArrayClass (k, NULL);
+ return type (k);
+ }
+
+ void compute_argument_types (_Jv_Utf8Const *signature,
+ type *types)
+ {
+ char *p = signature->data;
+ // Skip `('.
+ ++p;
+
+ int i = 0;
+ while (*p != ')')
+ types[i++] = get_one_type (p);
+ }
+
+ type compute_return_type (_Jv_Utf8Const *signature)
+ {
+ char *p = signature->data;
+ while (*p != ')')
+ ++p;
+ ++p;
+ return get_one_type (p);
+ }
+
+ void check_return_type (type expected)
+ {
+ type rt = compute_return_type (current_method->self->signature);
+ if (! expected.compatible (rt))
+ verify_fail ("incompatible return type");
+ }
+
+ void verify_instructions_0 ()
+ {
+ current_state = new state (current_method->max_stack,
+ current_method->max_locals);
+
+ PC = 0;
+
+ {
+ int var = 0;
+
+ using namespace java::lang::reflect;
+ if (! Modifier::isStatic (current_method->self->accflags))
+ {
+ type kurr (current_class);
+ if (_Jv_equalUtf8Consts (current_method->self->name, gcj::init_name))
+ kurr.set_uninitialized (type::SELF);
+ set_variable (0, kurr);
+ ++var;
+ }
+
+ if (var + _Jv_count_arguments (current_method->self->signature)
+ > current_method->max_locals)
+ verify_fail ("too many arguments");
+ compute_argument_types (current_method->self->signature,
+ ¤t_state->locals[var]);
+ }
+
+ states = (state **) _Jv_Malloc (sizeof (state *)
+ * current_method->code_length);
+ for (int i = 0; i < current_method->code_length; ++i)
+ states[i] = NULL;
+
+ next_verify_pc = state::NO_NEXT;
+
+ while (true)
+ {
+ // If the PC was invalidated, get a new one from the work list.
+ if (PC == state::NO_NEXT)
+ {
+ PC = pop_jump ();
+ if (PC == state::INVALID)
+ verify_fail ("saw state::INVALID");
+ if (PC == state::NO_NEXT)
+ break;
+ // Set up the current state.
+ *current_state = *states[PC];
+ }
+
+ // Control can't fall off the end of the bytecode.
+ if (PC >= current_method->code_length)
+ verify_fail ("fell off end");
+
+ if (states[PC] != NULL)
+ {
+ // We've already visited this instruction. So merge the
+ // states together. If this yields no change then we don't
+ // have to re-verify.
+ if (! current_state->merge (states[PC], false,
+ current_method->max_stack))
+ {
+ invalidate_pc ();
+ continue;
+ }
+ // Save a copy of it for later.
+ states[PC]->copy (current_state, current_method->max_stack,
+ current_method->max_locals);
+ }
+ else if ((flags[PC] & FLAG_BRANCH_TARGET))
+ {
+ // We only have to keep saved state at branch targets.
+ states[PC] = new state (current_state, current_method->max_stack,
+ current_method->max_locals);
+ }
+
+ // Update states for all active exception handlers. Ordinarily
+ // there are not many exception handlers. So we simply run
+ // through them all.
+ for (int i = 0; i < current_method->exc_count; ++i)
+ {
+ if (PC >= exception[i].start_pc && PC < exception[i].end_pc)
+ {
+ type handler = reference_type;
+ if (exception[i].handler_type != 0)
+ handler = check_class_constant (exception[i].handler_type);
+ push_exception_jump (handler, exception[i].handler_pc);
+ }
+ }
+
+ start_PC = PC;
+ unsigned char opcode = bytecode[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 (check_constant (get_byte ()));
+ break;
+ case op_ldc_w:
+ push_type (check_constant (get_ushort ()));
+ break;
+ case op_ldc2_w:
+ push_type (check_constant (get_ushort ()));
+ break;
+
+ case op_iload:
+ push_type (get_variable (get_byte (), int_type));
+ break;
+ case op_lload:
+ push_type (get_variable (get_byte (), long_type));
+ break;
+ case op_fload:
+ push_type (get_variable (get_byte (), float_type));
+ break;
+ case op_dload:
+ push_type (get_variable (get_byte (), double_type));
+ break;
+ case op_aload:
+ push_type (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 (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 (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 (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 (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 (get_variable (opcode - op_aload_0, reference_type));
+ break;
+ case op_iaload:
+ pop_type (int_type);
+ push_type (require_array_type (pop_type (reference_type),
+ int_type));
+ break;
+ case op_laload:
+ pop_type (int_type);
+ push_type (require_array_type (pop_type (reference_type),
+ long_type));
+ break;
+ case op_faload:
+ pop_type (int_type);
+ push_type (require_array_type (pop_type (reference_type),
+ float_type));
+ break;
+ case op_daload:
+ pop_type (int_type);
+ push_type (require_array_type (pop_type (reference_type),
+ double_type));
+ break;
+ case op_aaload:
+ pop_type (int_type);
+ push_type (require_array_type (pop_type (reference_type),
+ reference_type));
+ break;
+ case op_baload:
+ pop_type (int_type);
+ require_array_type (pop_type (reference_type), byte_type);
+ push_type (int_type);
+ break;
+ case op_caload:
+ pop_type (int_type);
+ require_array_type (pop_type (reference_type), char_type);
+ push_type (int_type);
+ break;
+ case op_saload:
+ pop_type (int_type);
+ require_array_type (pop_type (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_type (reference_type));
+ 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_type (reference_type));
+ break;
+ case op_iastore:
+ pop_type (int_type);
+ pop_type (int_type);
+ require_array_type (pop_type (reference_type), int_type);
+ break;
+ case op_lastore:
+ pop_type (long_type);
+ pop_type (int_type);
+ require_array_type (pop_type (reference_type), long_type);
+ break;
+ case op_fastore:
+ pop_type (float_type);
+ pop_type (int_type);
+ require_array_type (pop_type (reference_type), float_type);
+ break;
+ case op_dastore:
+ pop_type (double_type);
+ pop_type (int_type);
+ require_array_type (pop_type (reference_type), double_type);
+ break;
+ case op_aastore:
+ pop_type (reference_type);
+ pop_type (int_type);
+ require_array_type (pop_type (reference_type), reference_type);
+ break;
+ case op_bastore:
+ pop_type (int_type);
+ pop_type (int_type);
+ require_array_type (pop_type (reference_type), byte_type);
+ break;
+ case op_castore:
+ pop_type (int_type);
+ pop_type (int_type);
+ require_array_type (pop_type (reference_type), char_type);
+ break;
+ case op_sastore:
+ pop_type (int_type);
+ pop_type (int_type);
+ require_array_type (pop_type (reference_type), short_type);
+ break;
+ case op_pop:
+ pop32 ();
+ break;
+ case op_pop2:
+ pop64 ();
+ break;
+ case op_dup:
+ {
+ type t = pop32 ();
+ push_type (t);
+ push_type (t);
+ }
+ break;
+ case op_dup_x1:
+ {
+ type t1 = pop32 ();
+ type t2 = pop32 ();
+ push_type (t1);
+ push_type (t2);
+ push_type (t1);
+ }
+ break;
+ case op_dup_x2:
+ {
+ type t1 = pop32 ();
+ type t2 = pop32 ();
+ type t3 = pop32 ();
+ push_type (t1);
+ push_type (t3);
+ push_type (t2);
+ push_type (t1);
+ }
+ break;
+ case op_dup2:
+ {
+ type t = pop64 ();
+ push_type (t);
+ push_type (t);
+ }
+ break;
+ case op_dup2_x1:
+ {
+ type t1 = pop64 ();
+ type t2 = pop64 ();
+ push_type (t1);
+ push_type (t2);
+ push_type (t1);
+ }
+ break;
+ case op_dup2_x2:
+ {
+ type t1 = pop64 ();
+ type t2 = pop64 ();
+ type t3 = pop64 ();
+ push_type (t1);
+ push_type (t3);
+ push_type (t2);
+ push_type (t1);
+ }
+ break;
+ case op_swap:
+ {
+ type t1 = pop32 ();
+ type t2 = pop32 ();
+ push_type (t1);
+ push_type (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 (pop_type (int_type));
+ break;
+ 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:
+ pop_type (long_type);
+ push_type (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 (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 (pop_type (double_type));
+ break;
+ case op_ineg:
+ case op_i2b:
+ case op_i2c:
+ case op_i2s:
+ push_type (pop_type (int_type));
+ break;
+ case op_lneg:
+ push_type (pop_type (long_type));
+ break;
+ case op_fneg:
+ push_type (pop_type (float_type));
+ break;
+ case op_dneg:
+ push_type (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:
+ {
+ pop_type (int_type);
+ skip_padding ();
+ push_jump (get_int ());
+ jint low = get_int ();
+ jint high = get_int ();
+ // Already checked LOW -vs- HIGH.
+ for (int i = low; i <= high; ++i)
+ push_jump (get_int ());
+ invalidate_pc ();
+ }
+ break;
+
+ case op_lookupswitch:
+ {
+ pop_type (int_type);
+ skip_padding ();
+ push_jump (get_int ());
+ jint npairs = get_int ();
+ // Already checked NPAIRS >= 0.
+ jint lastkey = 0;
+ for (int i = 0; i < npairs; ++i)
+ {
+ jint key = get_int ();
+ if (i > 0 && key <= lastkey)
+ verify_fail ("lookupswitch pairs unsorted");
+ 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_type (reference_type));
+ invalidate_pc ();
+ break;
+ case op_return:
+ check_return_type (void_type);
+ invalidate_pc ();
+ break;
+ case op_getstatic:
+ push_type (check_field_constant (get_ushort ()));
+ break;
+ case op_putstatic:
+ pop_type (check_field_constant (get_ushort ()));
+ break;
+ case op_getfield:
+ {
+ type klass;
+ type field = check_field_constant (get_ushort (), &klass);
+ pop_type (klass);
+ push_type (field);
+ }
+ break;
+ case op_putfield:
+ {
+ type klass;
+ type field = check_field_constant (get_ushort (), &klass);
+ pop_type (field);
+ pop_type (klass);
+ }
+ break;
+
+ case op_invokevirtual:
+ case op_invokespecial:
+ case op_invokestatic:
+ case op_invokeinterface:
+ {
+ _Jv_Utf8Const *method_name, *method_signature;
+ type class_type
+ = check_method_constant (get_ushort (),
+ opcode == (unsigned char) op_invokeinterface,
+ &method_name,
+ &method_signature);
+ int arg_count = _Jv_count_arguments (method_signature);
+ if (opcode == (unsigned char) op_invokeinterface)
+ {
+ int nargs = get_byte ();
+ if (nargs == 0)
+ verify_fail ("too few arguments to invokeinterface");
+ if (get_byte () != 0)
+ verify_fail ("invokeinterface dummy byte is wrong");
+ if (nargs - 1 != arg_count)
+ verify_fail ("wrong argument count for invokeinterface");
+ }
+
+ bool is_init = false;
+ if (_Jv_equalUtf8Consts (method_name, gcj::init_name))
+ {
+ is_init = true;
+ if (opcode != (unsigned char) op_invokespecial)
+ verify_fail ("can't invoke <init>");
+ }
+ else if (method_name->data[0] == '<')
+ verify_fail ("can't invoke method starting with `<'");
+
+ // Pop arguments and check types.
+ type arg_types[arg_count];
+ compute_argument_types (method_signature, arg_types);
+ for (int i = arg_count - 1; i >= 0; --i)
+ pop_type (arg_types[i]);
+
+ if (opcode != (unsigned char) op_invokestatic)
+ {
+ type t = class_type;
+ if (is_init)
+ {
+ // In this case the PC doesn't matter.
+ t.set_uninitialized (type::UNINIT);
+ }
+ t = pop_type (t);
+ if (is_init)
+ current_state->set_initialized (t.get_pc (),
+ current_method->max_locals);
+ }
+
+ type rt = compute_return_type (method_signature);
+ if (! rt.isvoid ())
+ push_type (rt);
+ }
+ break;
+
+ case op_new:
+ {
+ type t = check_class_constant (get_ushort ());
+ if (t.isarray () || t.isinterface () || t.isabstract ())
+ verify_fail ("type is array, interface, or abstract");
+ t.set_uninitialized (start_PC);
+ push_type (t);
+ }
+ break;
+
+ case op_newarray:
+ {
+ int atype = get_byte ();
+ // We intentionally have chosen constants to make this
+ // valid.
+ if (atype < boolean_type || atype > long_type)
+ verify_fail ("type not primitive");
+ pop_type (int_type);
+ push_type (construct_primitive_array_type (type_val (atype)));
+ }
+ break;
+ case op_anewarray:
+ pop_type (int_type);
+ push_type (check_class_constant (get_ushort ()));
+ break;
+ case op_arraylength:
+ {
+ type t = pop_type (reference_type);
+ if (! t.isarray ())
+ verify_fail ("array type expected");
+ push_type (int_type);
+ }
+ break;
+ case op_athrow:
+ pop_type (type (&java::lang::Throwable::class$));
+ invalidate_pc ();
+ break;
+ case op_checkcast:
+ pop_type (reference_type);
+ push_type (check_class_constant (get_ushort ()));
+ break;
+ case op_instanceof:
+ pop_type (reference_type);
+ check_class_constant (get_ushort ());
+ push_type (int_type);
+ break;
+ case op_monitorenter:
+ pop_type (reference_type);
+ break;
+ case op_monitorexit:
+ pop_type (reference_type);
+ break;
+ case op_wide:
+ {
+ switch (get_byte ())
+ {
+ case op_iload:
+ push_type (get_variable (get_ushort (), int_type));
+ break;
+ case op_lload:
+ push_type (get_variable (get_ushort (), long_type));
+ break;
+ case op_fload:
+ push_type (get_variable (get_ushort (), float_type));
+ break;
+ case op_dload:
+ push_type (get_variable (get_ushort (), double_type));
+ break;
+ case op_aload:
+ push_type (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_type (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 ("unrecognized wide instruction");
+ }
+ }
+ break;
+ case op_multianewarray:
+ {
+ type atype = check_class_constant (get_ushort ());
+ int dim = get_byte ();
+ if (dim < 1)
+ verify_fail ("too few dimensions to multianewarray");
+ atype.verify_dimensions (dim);
+ for (int i = 0; i < dim; ++i)
+ pop_type (int_type);
+ push_type (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 ("unrecognized instruction");
+ }
+ }
+ }
+
+public:
+
+ void verify_instructions ()
+ {
+ branch_prepass ();
+ verify_instructions_0 ();
+ }
+
+ _Jv_BytecodeVerifier (_Jv_InterpMethod *m)
+ {
+ current_method = m;
+ bytecode = m->bytecode ();
+ exception = m->exceptions ();
+ current_class = m->defining_class;
+
+ states = NULL;
+ flags = NULL;
+ jsr_ptrs = NULL;
+ }
+
+ ~_Jv_BytecodeVerifier ()
+ {
+ if (states)
+ _Jv_Free (states);
+ if (flags)
+ _Jv_Free (flags);
+ if (jsr_ptrs)
+ _Jv_Free (jsr_ptrs);
+ }
+};
+
+void
+_Jv_VerifyMethod (_Jv_InterpMethod *meth)
+{
+ _Jv_BytecodeVerifier v (meth);
+ v.verify_instructions ();
+}
+
+// FIXME: add more info, like PC, when required.
+static void
+verify_fail (char *s)
+{
+ char buf[1024];
+ strcpy (buf, "verification failed: ");
+ strcat (buf, s);
+ throw new java::lang::VerifyError (JvNewStringLatin1 (buf));
+}
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