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/* Glue to interface gcj with bytecode verifier.

   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2010

   Free Software Foundation, Inc.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the Free Software Foundation; either version 3, or (at your option)

any later version.

GCC is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

GNU General Public License for more details.

You should have received a copy of the GNU General Public License

along with GCC; see the file COPYING3.  If not see

<http://www.gnu.org/licenses/>.

Java and all Java-based marks are trademarks or registered trademarks

of Sun Microsystems, Inc. in the United States and other countries.

The Free Software Foundation is independent of Sun Microsystems, Inc.  */

/* Written by Tom Tromey <tromey@redhat.com>.  */

#include "config.h"

#include "system.h"

#include "coretypes.h"

#include "tree.h"

#include "parse.h"

#include "verify.h"

#include "java-tree.h"

#include "java-except.h"

#include "diagnostic-core.h"

void *

vfy_alloc (size_t bytes)

{

  return xmalloc (bytes);

}

void

vfy_free (void *mem)

{

  free (mem);

}

bool

vfy_strings_equal (vfy_string one, vfy_string two)

{

  return one == two;

}

const char *

vfy_string_bytes (vfy_string str)

{

  return IDENTIFIER_POINTER (str);

}

int

vfy_string_length (vfy_string str)

{

  return IDENTIFIER_LENGTH (str);

}

vfy_string

vfy_init_name (void)

{

  return init_identifier_node;

}

vfy_string

vfy_clinit_name (void)

{

  return clinit_identifier_node;

}

static const char*

skip_one_type (const char* ptr)

{

  int ch = *ptr++;

  while (ch == '[')

    {

      ch = *ptr++;

    }

  if (ch == 'L')

    {

      do { ch = *ptr++; } while (ch != ';');

    }

  return ptr;

}

int

vfy_count_arguments (vfy_string signature)

{

  const char *ptr = IDENTIFIER_POINTER (signature);

  int arg_count = 0;

  /* Skip '('.  */

  ptr++;

  /* Count args.  */

  while (*ptr != ')')

    {

      ptr = skip_one_type (ptr);

      arg_count += 1;

    }

  return arg_count;

}

vfy_string

vfy_get_string (const char *s, int len)

{

  return get_identifier_with_length (s, len);

}

vfy_string

vfy_get_signature (vfy_method *method)

{

  return method->signature;

}

vfy_string

vfy_get_method_name (vfy_method *method)

{

  return method->name;

}

bool

vfy_is_static (vfy_method *method)

{

  return METHOD_STATIC (method->method);

}

const unsigned char *

vfy_get_bytecode (vfy_method *method)

{

  return method->bytes;

}

vfy_exception *

vfy_get_exceptions (vfy_method *method)

{

  return method->exceptions;

}

void

vfy_get_exception (vfy_exception *exceptions, int index, int *handler,

                   int *start, int *end, int *handler_type)

{

  *handler = exceptions[index].handler;

  *start = exceptions[index].start;

  *end = exceptions[index].end;

  *handler_type = exceptions[index].type;

}

int

vfy_tag (vfy_constants *pool, int index)

{

  int result = JPOOL_TAG (pool, index);

  /* gcj will resolve constant pool entries other than string and

     class references.  The verifier doesn't care about the values, so

     we just strip off the resolved flag.  */

  if ((result & CONSTANT_ResolvedFlag) != 0

      && result != CONSTANT_ResolvedString

      && result != CONSTANT_ResolvedClass)

    result &= ~ CONSTANT_ResolvedFlag;

  return result;

}

void

vfy_load_indexes (vfy_constants *pool, int index,

                  vfy_uint_16 *index0, vfy_uint_16 *index1)

{

  *index0 = JPOOL_USHORT1 (pool, index);

  *index1 = JPOOL_USHORT2 (pool, index);

}

vfy_constants *

vfy_get_constants (vfy_jclass klass)

{

  return TYPE_JCF (klass);

}

int

vfy_get_constants_size (vfy_jclass klass)

{

  return JPOOL_SIZE (TYPE_JCF (klass));

}

vfy_string

vfy_get_pool_string (vfy_constants *pool, int index)

{

  return get_name_constant (pool, index);

}

vfy_jclass

vfy_get_pool_class (vfy_constants *pool, int index)

{

  vfy_jclass k;

  k = get_class_constant (pool, index);

  return k;

}

vfy_string

vfy_get_class_name (vfy_jclass klass)

{

  return DECL_NAME (TYPE_NAME (klass));

}

bool

vfy_is_assignable_from (vfy_jclass target, vfy_jclass source)

{

  /* Any class is always assignable to itself, or java.lang.Object. */

  if (source == target || target == object_type_node)

    return true;

  /* For the C++ ABI, perform this test statically. */

  if (! flag_indirect_dispatch)

    return can_widen_reference_to (source, target);

  /* For the BC-ABI, we assume at compile time that reference types are always

  compatible.  However, a type assertion table entry is emitted so that the

  runtime can detect binary-incompatible changes.  */

  add_type_assertion (current_class, JV_ASSERT_TYPES_COMPATIBLE, source,

                      target);

  return true;

}

char

vfy_get_primitive_char (vfy_jclass klass)

{

  tree sig;

  gcc_assert (vfy_is_primitive (klass));

  sig = build_java_signature (klass);

  return (IDENTIFIER_POINTER (sig))[0];

}

bool

vfy_is_array (vfy_jclass klass)

{

  return TYPE_ARRAY_P (klass);

}

bool

vfy_is_interface (vfy_jclass klass)

{

  return CLASS_INTERFACE (TYPE_NAME (klass));

}

bool

vfy_is_primitive (vfy_jclass klass)

{

  return JPRIMITIVE_TYPE_P (klass);

}

vfy_jclass

vfy_get_superclass (vfy_jclass klass)

{

  vfy_jclass k;

  k = CLASSTYPE_SUPER (klass);

  return k;

}

vfy_jclass

vfy_get_array_class (vfy_jclass klass)

{

  vfy_jclass k;

  k = build_java_array_type (klass, -1);

  return k;

}

vfy_jclass

vfy_get_component_type (vfy_jclass klass)

{

  vfy_jclass k;

  gcc_assert (vfy_is_array (klass));

  k = TYPE_ARRAY_ELEMENT (klass);

  if (TREE_CODE (k) == POINTER_TYPE)

    k = TREE_TYPE (k);

  return k;

}

bool

vfy_is_abstract (vfy_jclass klass)

{

  return CLASS_ABSTRACT (TYPE_NAME (klass));

}

vfy_jclass

vfy_find_class (vfy_jclass ignore ATTRIBUTE_UNUSED, vfy_string name)

{

  vfy_jclass k;

  k = get_type_from_signature (name);

  if (TREE_CODE (k) == POINTER_TYPE)

    k = TREE_TYPE (k);

  return k;

}

vfy_jclass

vfy_object_type (void)

{

  vfy_jclass k;

  k = object_type_node;

  return k;

}

vfy_jclass

vfy_class_type (void)

{

  return class_type_node;

}

vfy_jclass

vfy_string_type (void)

{

  vfy_jclass k;

  k = string_type_node;

  return k;

}

vfy_jclass

vfy_throwable_type (void)

{

  vfy_jclass k;

  k = throwable_type_node;

  return k;

}

vfy_jclass

vfy_unsuitable_type (void)

{

  return TYPE_SECOND;

}

vfy_jclass

vfy_return_address_type (void)

{

  return TYPE_RETURN_ADDR;

}

vfy_jclass

vfy_null_type (void)

{

  return TYPE_NULL;

}

bool

vfy_class_has_field (vfy_jclass klass, vfy_string name,

                     vfy_string signature)

{

  tree field = TYPE_FIELDS (klass);

  while (field != NULL_TREE)

    {

      if (DECL_NAME (field) == name

          && build_java_signature (TREE_TYPE (field)) == signature)

        return true;

      field = DECL_CHAIN (field);

    }

  return false;

}

int

vfy_fail (const char *message, int pc, vfy_jclass ignore1 ATTRIBUTE_UNUSED,

          vfy_method *ignore2 ATTRIBUTE_UNUSED)

{

  if (pc == -1)

    error ("verification failed: %s", message);

  else

    error ("verification failed at PC=%d: %s", pc, message);

  /* We have to return a value for the verifier to throw.  */

  return 1;

}

vfy_jclass

vfy_get_primitive_type (int type)

{

  vfy_jclass k;

  k = decode_newarray_type (type);

  return k;

}

void

vfy_note_stack_depth (vfy_method *method, int pc, int depth)

{

  tree val = make_tree_vec (method->max_locals + depth);

  VEC_replace (tree, type_states, pc, val);

  /* Called for side effects.  */

  lookup_label (pc);

}

void

vfy_note_stack_type (vfy_method *method, int pc, int slot, vfy_jclass type)

{

  tree vec;

  slot += method->max_locals;

  if (type == object_type_node)

    type = object_ptr_type_node;

  vec = VEC_index (tree, type_states, pc);

  TREE_VEC_ELT (vec, slot) = type;

  /* Called for side effects.  */

  lookup_label (pc);

}

void

vfy_note_local_type (vfy_method *method ATTRIBUTE_UNUSED, int pc, int slot,

                     vfy_jclass type)

{

  tree vec;

  if (type == object_type_node)

    type = object_ptr_type_node;

  vec = VEC_index (tree, type_states, pc);

  TREE_VEC_ELT (vec, slot) = type;

  /* Called for side effects.  */

  lookup_label (pc);

}

void

vfy_note_instruction_seen (int pc)

{

  instruction_bits[pc] |= BCODE_VERIFIED;

}

/* Verify the bytecodes of the current method.

   Return 1 on success, 0 on failure. */

int

verify_jvm_instructions_new (JCF *jcf, const unsigned char *byte_ops,

                         long length)

{

  vfy_method method;

  int i, result, eh_count;

  vfy_exception *exceptions;

  method_init_exceptions ();

  JCF_SEEK (jcf, DECL_CODE_OFFSET (current_function_decl) + length);

  eh_count = JCF_readu2 (jcf);

  exceptions = (vfy_exception *) xmalloc (eh_count * sizeof (vfy_exception));

  for (i = 0; i < eh_count; ++i)

    {

      int start_pc, end_pc, handler_pc, catch_type;

      unsigned char *p = jcf->read_ptr + 8 * i;

      start_pc = GET_u2 (p);

      end_pc = GET_u2 (p+2);

      handler_pc = GET_u2 (p+4);

      catch_type = GET_u2 (p+6);

      if (start_pc < 0 || start_pc >= length

          || end_pc < 0 || end_pc > length || start_pc >= end_pc

          || handler_pc < 0 || handler_pc >= length)

        {

          error ("bad pc in exception_table");

          free (exceptions);

          return 0;

        }

      exceptions[i].handler = handler_pc;

      exceptions[i].start = start_pc;

      exceptions[i].end = end_pc;

      exceptions[i].type = catch_type;

      add_handler (start_pc, end_pc,

                   lookup_label (handler_pc),

                   catch_type == 0 ? NULL_TREE

                   : get_class_constant (jcf, catch_type));

      instruction_bits[handler_pc] |= BCODE_EXCEPTION_TARGET;

    }

  gcc_assert (sanity_check_exception_range (&whole_range));

  method.method = current_function_decl;

  method.signature = build_java_signature (TREE_TYPE (current_function_decl));

  method.name = DECL_NAME (current_function_decl);

  method.bytes = byte_ops;

  method.exceptions = exceptions;

  method.defining_class = DECL_CONTEXT (current_function_decl);

  method.max_stack = DECL_MAX_STACK (current_function_decl);

  method.max_locals = DECL_MAX_LOCALS (current_function_decl);

  method.code_length = length;

  method.exc_count = eh_count;

  result = verify_method (&method);

  free (exceptions);

  return result;

}