verify.c: Insert a short blurb at the start referring to the JVMS.

	* verify.c: Insert a short blurb at the start referring to the JVMS.
	Minor formatting fixes all over the place.
	(merge_type_state): Remove redundant nested if statement.
	(verify_jvm_instructions): Ensure current_subr is initialised to
	NULL_TREE.

Cii: Enter Log.  Lines beginning with `CVS:' are removed automaticalli

From-SVN: r84084

1 files changed, 205 insertions, 108 deletions

diff --git a/gcc/java/verify.c b/gcc/java/verify.c
index ed3f945..750c517 100644
--- a/gcc/java/verify.c
+++ b/gcc/java/verify.c
@@ -24,6 +24,11 @@ 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.  */
 
+/* This bytecode verifier is an implementation of the bytecode
+verification process described in section 4.9 of "The Java(TM) Virtual
+Machine Specification", Second Edition, by Tim Lindholm and Frank Yellin,
+published by Addison-Wesley in 1999.  */
+
 #include "config.h"
 #include "system.h"
 #include "coretypes.h"
@@ -82,7 +87,7 @@ check_pending_block (tree target_label)
       push_pending_label (target_label);
     }
 
-  if (current_subr == NULL)
+  if (current_subr == NULL_TREE)
     {
       if (LABEL_IN_SUBR (target_label))
 	return "might transfer control into subroutine";
@@ -113,7 +118,7 @@ subroutine_nesting (tree label)
   int nesting = 0;
   while (label != NULL_TREE && LABEL_IN_SUBR (label))
     {
-      if (! LABEL_IS_SUBR_START(label))
+      if (! LABEL_IS_SUBR_START (label))
 	label = LABEL_SUBR_START (label);
       label = LABEL_SUBR_CONTEXT (label);
       nesting++;
@@ -250,11 +255,9 @@ merge_type_state (tree label)
   tree return_map;
   if (vec == NULL_TREE)
     {
-      if (!vec)
-	{
-	  vec = make_tree_vec (cur_length);
-	  LABEL_TYPE_STATE (label) = vec;
-	}
+      vec = make_tree_vec (cur_length);
+      LABEL_TYPE_STATE (label) = vec;
+
       while (--cur_length >= 0)
 	TREE_VEC_ELT (vec, cur_length) = type_map [cur_length];
       return 1;
@@ -281,7 +284,7 @@ merge_type_state (tree label)
 	      /* If there has been a change, note that since we must re-verify.
 		 However, if the label is the start of a subroutine,
 		 we don't care about local variables that are neither
-		 set nor used in the sub-routine. */
+		 set nor used in the subroutine. */
 	      if (return_map == NULL_TREE || i >= nlocals
 		  || TREE_VEC_ELT (return_map, i) != TYPE_UNUSED
 		  || (TYPE_IS_WIDE (new_type)
@@ -306,33 +309,33 @@ merge_type_state (tree label)
 static void
 type_stack_dup (int size, int offset)
 {
-  tree type[4];
+  tree type [4];
   int index;
   for (index = 0;  index < size + offset; index++)
     {
-      type[index] = stack_type_map[stack_pointer - 1];
-      if (type[index] == void_type_node)
+      type [index] = stack_type_map [stack_pointer - 1];
+      if (type [index] == void_type_node)
 	{
 	  index++;
-	  type[index] = stack_type_map[stack_pointer - 2];
-	  if (! TYPE_IS_WIDE (type[index]))
+	  type [index] = stack_type_map [stack_pointer - 2];
+	  if (! TYPE_IS_WIDE (type [index]))
 	    abort ();
 	  if (index == size || index == size + offset)
 	    /* Dup operation splits 64-bit number.  */
 	    abort ();
 	}
-      pop_type (type[index]);
+      pop_type (type [index]);
     }
   for (index = size;  --index >= 0; )
     {
-      if (type[index] != void_type_node)
-	push_type (type[index]);
+      if (type [index] != void_type_node)
+	push_type (type [index]);
     }
 
   for (index = size + offset;  --index >= 0; )
     {
-      if (type[index] != void_type_node)
-	push_type (type[index]);
+      if (type [index] != void_type_node)
+	push_type (type [index]);
     }
 }
 
@@ -437,7 +440,9 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 
   pending_blocks = NULL_TREE;
 
-  /* Handle the exception table. */
+  current_subr = NULL_TREE;
+
+  /* Handle the exception table.  */
   method_init_exceptions ();
   JCF_SEEK (jcf, DECL_CODE_OFFSET (current_function_decl) + length);
   eh_count = JCF_readu2 (jcf);
@@ -447,8 +452,8 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
   starts = xmalloc (eh_count * sizeof (struct pc_index));
   for (i = 0; i < eh_count; ++i)
     {
-      starts[i].start_pc = GET_u2 (jcf->read_ptr + 8 * i);
-      starts[i].index = i;
+      starts [i].start_pc = GET_u2 (jcf->read_ptr + 8 * i);
+      starts [i].index = i;
     }
   qsort (starts, eh_count, sizeof (struct pc_index), start_pc_cmp);
 
@@ -456,7 +461,7 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
     {
       int start_pc, end_pc, handler_pc, catch_type;
 
-      p = jcf->read_ptr + 8 * starts[i].index;
+      p = jcf->read_ptr + 8 * starts [i].index;
 
       start_pc = GET_u2 (p);
       end_pc = GET_u2 (p+2);
@@ -490,6 +495,7 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
   for (PC = 0;;)
     {
       tree type, tmp;
+
       if (((PC != INVALID_PC
 	   && instruction_bits [PC] & BCODE_TARGET) != 0)
 	  || PC == 0)
@@ -497,57 +503,61 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	  PUSH_PENDING (lookup_label (PC));
 	  INVALIDATE_PC;
 	}
+
       /* Check if there are any more pending blocks in the current
 	 subroutine.  Because we push pending blocks in a
 	 last-in-first-out order, and because we don't push anything
 	 from our caller until we are done with this subroutine or
-	 anything nested in it, then we are done if the top of the
+	 anything nested in it, we are done if the top of the
 	 pending_blocks stack is not in a subroutine, or it is in our
 	 caller. */
-      if (current_subr 
-	  && PC == INVALID_PC)
+      if (current_subr && PC == INVALID_PC)
 	{
 	  if (pending_blocks == NULL_TREE
 	      || (subroutine_nesting (pending_blocks)
 		  < subroutine_nesting (current_subr)))
 	    {
-	      int size = DECL_MAX_LOCALS(current_function_decl)+stack_pointer;
+	      int size
+                = DECL_MAX_LOCALS (current_function_decl) + stack_pointer;
+
 	      tree ret_map = LABEL_RETURN_TYPE_STATE (current_subr);
 	      tmp = LABEL_RETURN_LABELS (current_subr);
 	      
 	      /* FIXME: If we exit a subroutine via a throw, we might
 		 have returned to an earlier caller.  Obviously a
 		 "ret" can only return one level, but a throw may
-		 return many levels.*/
+		 return many levels.  */
 	      current_subr = LABEL_SUBR_CONTEXT (current_subr);
 
 	      if (RETURN_MAP_ADJUSTED (ret_map))
 		{
-		  /* Since we are done with this subroutine , set up
+		  /* Since we are done with this subroutine, set up
 		     the (so far known) return address as pending -
-		     with the merged type state. */
+		     with the merged type state.  */
 		  for ( ; tmp != NULL_TREE;  tmp = TREE_CHAIN (tmp))
 		    {
 		      tree return_label = TREE_VALUE (tmp);
 		      tree return_state = LABEL_TYPE_STATE (return_label);
 		      if (return_state == NULL_TREE)
 			{
-			  /* This means means we had not verified the
-			     subroutine earlier, so this is the first jsr to
-			     call it.  In this case, the type_map of the return
+			  /* This means we had not verified the subroutine
+                             earlier, so this is the first jsr to call it.
+                             In this case, the type_map of the return
 			     address is just the current type_map - and that
-			     is handled by the following PUSH_PENDING. */
+			     is handled by the following PUSH_PENDING.  */
 			}
 		      else
 			{
 			  /* In this case we have to do a merge.  But first
 			     restore the type_map for unused slots to those
-			     that were in effect at the jsr. */
-			  for (index = size;  --index >= 0; )
+			     that were in effect at the jsr.  */
+			  for (index = size; --index >= 0; )
 			    {
-			      type_map[index] = TREE_VEC_ELT (ret_map, index);
-			      if (type_map[index] == TYPE_UNUSED)
-				type_map[index]
+			      type_map [index]
+                                = TREE_VEC_ELT (ret_map, index);
+
+			      if (type_map [index] == TYPE_UNUSED)
+				type_map [index]
 				  = TREE_VEC_ELT (return_state, index);
 			    }
 			}
@@ -556,11 +566,14 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 		}
 	    }
 	}
+
       if (PC == INVALID_PC)
 	{
 	  label = pending_blocks;
+
 	  if (label == NULL_TREE)
 	    break;  /* We're done! */
+
 	  pending_blocks = LABEL_PENDING_CHAIN (label);
 	  LABEL_CHANGED (label) = 0;
 
@@ -571,52 +584,60 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 
 	  /* Restore type_map and stack_pointer from
 	     LABEL_TYPE_STATE (label), and continue
-	     compiling from there. */
+	     compiling from there.  */
 	  load_type_state (label);
+
 	  PC = LABEL_PC (label);
 	}
       else if (PC >= length)
-	VERIFICATION_ERROR ("falling through end of method");
+	VERIFICATION_ERROR ("falling through the end of the method");
 
-      /* fprintf (stderr, "** %d\n", PC); */
 
       oldpc = PC;
 
-      if (!(instruction_bits [PC] & BCODE_INSTRUCTION_START) && ! wide)
+      if (! (instruction_bits [PC] & BCODE_INSTRUCTION_START) && ! wide)
 	VERIFICATION_ERROR ("PC not at instruction start");
 
-      instruction_bits[PC] |= BCODE_VERIFIED;
+      instruction_bits [PC] |= BCODE_VERIFIED;
 
       eh_ranges = find_handler (oldpc);
 
-      op_code = byte_ops[PC++];
+      op_code = byte_ops [PC++];
       switch (op_code)
 	{
 	  int is_static, is_putting;
+
 	case OPCODE_nop:
 	  break;
+
 	case OPCODE_iconst_m1:
 	case OPCODE_iconst_0:	case OPCODE_iconst_1:	case OPCODE_iconst_2:
 	case OPCODE_iconst_3:	case OPCODE_iconst_4:	case OPCODE_iconst_5:
 	  i = op_code - OPCODE_iconst_0;
 	  goto push_int;
 	push_int:
-	  if (byte_ops[PC] == OPCODE_newarray
-	      || byte_ops[PC] == OPCODE_anewarray)
+	  if (byte_ops [PC] == OPCODE_newarray
+	      || byte_ops [PC] == OPCODE_anewarray)
 	    int_value = i;
 	  PUSH_TYPE (int_type_node);  break;
+
 	case OPCODE_lconst_0:	case OPCODE_lconst_1:
 	  PUSH_TYPE (long_type_node);  break;
+
 	case OPCODE_fconst_0:	case OPCODE_fconst_1:	case OPCODE_fconst_2:
 	  PUSH_TYPE (float_type_node);  break;
+
 	case OPCODE_dconst_0:	case OPCODE_dconst_1:
 	  PUSH_TYPE (double_type_node);  break;
+
 	case OPCODE_bipush:
 	  i = IMMEDIATE_s1;
 	  goto push_int;
+
 	case OPCODE_sipush:
 	  i = IMMEDIATE_s2;
 	  goto push_int;
+
 	case OPCODE_iload:  type = int_type_node;  goto general_load;
 	case OPCODE_lload:  type = long_type_node;  goto general_load;
 	case OPCODE_fload:  type = float_type_node;  goto general_load;
@@ -652,13 +673,13 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 		>= DECL_MAX_LOCALS (current_function_decl)))
 	  VERIFICATION_ERROR_WITH_INDEX
 	    ("invalid local variable index %d in load");
-	tmp = type_map[index];
+	tmp = type_map [index];
 	if (tmp == TYPE_UNKNOWN)
 	  VERIFICATION_ERROR_WITH_INDEX
 	    ("loading local variable %d which has unknown type");
 	else if (tmp == TYPE_SECOND
 	    || (TYPE_IS_WIDE (type)
-		&& type_map[index+1] != void_type_node)
+		&& type_map [index+1] != void_type_node)
 	    || (type == ptr_type_node
 		? TREE_CODE (tmp) != POINTER_TYPE
 		: type == int_type_node
@@ -707,21 +728,23 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	    return 0;
 	  }
 	POP_TYPE_CONV (type, type, NULL);
-	type_map[index] = type;
+	type_map [index] = type;
 
-	/* If local variable changed, we need to reconsider eh handlers. */
+	/* If a local variable has changed, we need to reconsider exception
+        handlers.  */
 	prev_eh_ranges = NULL_EH_RANGE;
 
 	/* Allocate decl and rtx for this variable now, so if we're not
-	   optimizing, we get a temporary that survives the whole method. */
+	   optimizing, we get a temporary that survives the whole method.  */
 	find_local_variable (index, type, oldpc);
 
         if (TYPE_IS_WIDE (type))
-          type_map[index+1] = TYPE_SECOND;
+          type_map [index+1] = TYPE_SECOND;
+
 	/* ... fall through to note_used ... */
 	note_used:
 	  /* For store or load, note that local variable INDEX is used.
-	     This is needed to verify try-finally sub-routines. */
+	     This is needed to verify try-finally subroutines. */
 	  if (current_subr)
 	    {
 	      tree vec = LABEL_RETURN_TYPE_STATE (current_subr);
@@ -772,15 +795,18 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	  type = double_type_node;  goto binop;
 	case OPCODE_dneg:
 	  type = double_type_node;  goto unop;
+
 	unop:
 	  pop_type (type);
 	  PUSH_TYPE (type);
 	  break;
+
 	binop:
 	  pop_type (type);
 	  pop_type (type);
 	  PUSH_TYPE (type);
 	  break;
+
 	case OPCODE_lshl:
 	case OPCODE_lshr:
 	case OPCODE_lushr:
@@ -788,17 +814,19 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	  pop_type (long_type_node);
 	  PUSH_TYPE (long_type_node);
 	  break;
+
 	case OPCODE_iinc:
 	  index = wide ? IMMEDIATE_u2 : IMMEDIATE_u1;
 	  PC += wide + 1;
 	  wide = 0;
 	  if (index < 0 || index >= DECL_MAX_LOCALS (current_function_decl))
 	    VERIFICATION_ERROR ("invalid local variable index in iinc");
-	  tmp = type_map[index];
+	  tmp = type_map [index];
 	  if (tmp == NULL_TREE
 	      || ! INTEGRAL_TYPE_P (tmp) || TYPE_PRECISION (tmp) > 32)
 	    VERIFICATION_ERROR ("invalid local variable type in iinc");
 	  break;
+
 	case OPCODE_i2l:
 	  pop_type (int_type_node);    PUSH_TYPE (long_type_node);   break;
 	case OPCODE_i2f:
@@ -823,6 +851,7 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	  pop_type (double_type_node); PUSH_TYPE (long_type_node);   break;
 	case OPCODE_d2f:
 	  pop_type (double_type_node); PUSH_TYPE (float_type_node);  break;
+
 	case OPCODE_lcmp:
 	  type = long_type_node;  goto compare;
 	case OPCODE_fcmpl:
@@ -834,6 +863,7 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	compare:
 	  pop_type (type);  pop_type (type);
 	  PUSH_TYPE (int_type_node);  break;
+
 	case OPCODE_ifeq:
 	case OPCODE_ifne:
 	case OPCODE_iflt:
@@ -855,15 +885,18 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	case OPCODE_if_acmpne:
 	  pop_type (object_ptr_type_node);  pop_type (object_ptr_type_node);
 	  goto cond;
+
 	cond:
 	  PUSH_PENDING (lookup_label (oldpc + IMMEDIATE_s2));
 	  break;
+          
 	case OPCODE_goto:
 	  PUSH_PENDING (lookup_label (oldpc + IMMEDIATE_s2));
 	  INVALIDATE_PC;
 	  break;
+
 	case OPCODE_wide:
-	  switch (byte_ops[PC])
+	  switch (byte_ops [PC])
 	    {
 	    case OPCODE_iload:  case OPCODE_lload:
 	    case OPCODE_fload:  case OPCODE_dload:  case OPCODE_aload:
@@ -877,6 +910,7 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	      VERIFICATION_ERROR ("invalid use of wide instruction");
 	    }
 	  break;
+
 	case OPCODE_return:   type = void_type_node;   goto ret;
 	case OPCODE_ireturn:
 	  if ((TREE_CODE (return_type) == BOOLEAN_TYPE
@@ -896,13 +930,15 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	  else
 	    type = NULL_TREE;
 	  goto ret;
+
 	ret:
 	  if (type != return_type)
 	    VERIFICATION_ERROR ("incorrect ?return opcode");
 	  if (type != void_type_node)
-	    POP_TYPE(type, "return value has wrong type");
+	    POP_TYPE (type, "return value has wrong type");
 	  INVALIDATE_PC;
 	  break;
+
 	case OPCODE_getstatic: is_putting = 0;  is_static = 1;  goto field;
 	case OPCODE_putstatic: is_putting = 1;  is_static = 1;  goto field;
 	case OPCODE_getfield:  is_putting = 0;  is_static = 0;  goto field;
@@ -911,69 +947,90 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	  {
 	    tree field_signature, field_type;
 	    index = IMMEDIATE_u2;
-	    if (index <= 0 || index >= JPOOL_SIZE(current_jcf))
+
+	    if (index <= 0 || index >= JPOOL_SIZE (current_jcf))
 	      VERIFICATION_ERROR_WITH_INDEX ("bad constant pool index %d");
+
 	    if (JPOOL_TAG (current_jcf, index) != CONSTANT_Fieldref)
 	      VERIFICATION_ERROR
 		("field instruction does not reference a Fieldref");
-	    field_signature = COMPONENT_REF_SIGNATURE (&current_jcf->cpool, index);
+
+	    field_signature
+              = COMPONENT_REF_SIGNATURE (&current_jcf->cpool, index);
+
 	    field_type = get_type_from_signature (field_signature);
+
 	    if (is_putting)
 	      POP_TYPE (field_type, "incorrect type for field");
+
 	    if (! is_static)
 	      {
-		int clindex = COMPONENT_REF_CLASS_INDEX (&current_jcf->cpool,
-							index);
+		int clindex
+                  = COMPONENT_REF_CLASS_INDEX (&current_jcf->cpool, index);
+
 		tree self_type = get_class_constant (current_jcf, clindex);
+
 		/* Defer actual checking until next pass. */
-		POP_TYPE(self_type, "incorrect type for field reference");
+		POP_TYPE (self_type, "incorrect type for field reference");
 	      }
+
 	    if (! is_putting)
 	      PUSH_TYPE (field_type);
 	    break;
 	  }
+
 	case OPCODE_new:
 	  PUSH_TYPE (get_class_constant (jcf, IMMEDIATE_u2));
 	  break;
+
 	case OPCODE_dup:     wide = 1; index = 0;  goto dup;
 	case OPCODE_dup_x1:  wide = 1; index = 1;  goto dup;
 	case OPCODE_dup_x2:  wide = 1; index = 2;  goto dup;
 	case OPCODE_dup2:    wide = 2; index = 0;  goto dup;
 	case OPCODE_dup2_x1: wide = 2; index = 1;  goto dup;
 	case OPCODE_dup2_x2: wide = 2; index = 2;  goto dup;
+
 	dup:
 	  if (wide + index > stack_pointer)
 	    VERIFICATION_ERROR ("stack underflow - dup* operation");
 	  type_stack_dup (wide, index);
 	  wide = 0;
 	  break;
+
 	case OPCODE_pop:  index = 1;  goto pop;
 	case OPCODE_pop2: index = 2;  goto pop;
+
 	pop:
 	  if (stack_pointer < index)
 	    VERIFICATION_ERROR ("stack underflow");
 	  stack_pointer -= index;
 	  break;
+
 	case OPCODE_swap:
 	  if (stack_pointer < 2)
 	    VERIFICATION_ERROR ("stack underflow (in swap)");
 	  else
 	    {
-	      tree type1 = stack_type_map[stack_pointer - 1];
-	      tree type2 = stack_type_map[stack_pointer - 2];
+	      tree type1 = stack_type_map [stack_pointer - 1];
+	      tree type2 = stack_type_map [stack_pointer - 2];
+
 	      if (type1 == void_type_node || type2 == void_type_node)
 		VERIFICATION_ERROR ("verifier (swap):  double or long value");
-	      stack_type_map[stack_pointer - 2] = type1;
-	      stack_type_map[stack_pointer - 1] = type2;
+
+	      stack_type_map [stack_pointer - 2] = type1;
+	      stack_type_map [stack_pointer - 1] = type2;
 	    }
 	  break;
+
 	case OPCODE_ldc:   index = IMMEDIATE_u1;  goto ldc;
 	case OPCODE_ldc2_w:
 	case OPCODE_ldc_w:
 	  index = IMMEDIATE_u2;  goto ldc;
+
 	ldc:
-	  if (index <= 0 || index >= JPOOL_SIZE(current_jcf))
+	  if (index <= 0 || index >= JPOOL_SIZE (current_jcf))
 	    VERIFICATION_ERROR_WITH_INDEX ("bad constant pool index %d in ldc");
+
 	  int_value = -1;
 	  switch (JPOOL_TAG (current_jcf, index) & ~CONSTANT_ResolvedFlag)
 	    {
@@ -1005,10 +1062,13 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	    tree sig, method_name, method_type, self_type;
 	    int self_is_interface, tag;
 	    index = IMMEDIATE_u2;
-	    if (index <= 0 || index >= JPOOL_SIZE(current_jcf))
+
+	    if (index <= 0 || index >= JPOOL_SIZE (current_jcf))
 	      VERIFICATION_ERROR_WITH_INDEX
 		("bad constant pool index %d for invoke");
+
 	    tag = JPOOL_TAG (current_jcf, index);
+
 	    if (op_code == OPCODE_invokeinterface)
 	      {
 		if (tag != CONSTANT_InterfaceMethodref)
@@ -1020,18 +1080,25 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 		if (tag != CONSTANT_Methodref)
 		  VERIFICATION_ERROR ("invoke does not reference a Methodref");
 	      }
+
 	    sig = COMPONENT_REF_SIGNATURE (&current_jcf->cpool, index);
-	    self_type = get_class_constant
-	      (current_jcf, COMPONENT_REF_CLASS_INDEX (&current_jcf->cpool,
-						       index));
+
+	    self_type
+              = get_class_constant (current_jcf,
+                                    COMPONENT_REF_CLASS_INDEX
+                                      (&current_jcf->cpool, index));
+
 	    if (! CLASS_LOADED_P (self_type))
 	      load_class (self_type, 1);
+
 	    self_is_interface = CLASS_INTERFACE (TYPE_NAME (self_type));
 	    method_name = COMPONENT_REF_NAME (&current_jcf->cpool, index);
 	    method_type = parse_signature_string (IDENTIFIER_POINTER (sig),
 						  IDENTIFIER_LENGTH (sig));
+
 	    if (TREE_CODE (method_type) != FUNCTION_TYPE)
 	      VERIFICATION_ERROR ("bad method signature");
+
 	    pmessage = pop_argument_types (TYPE_ARG_TYPES (method_type));
 	    if (pmessage != NULL)
 	      {
@@ -1039,10 +1106,11 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 		goto pop_type_error;
 	      }
 
-	    /* Can't invoke <clinit> */
+	    /* Can't invoke <clinit>.  */
 	    if (ID_CLINIT_P (method_name))
 	      VERIFICATION_ERROR ("invoke opcode can't invoke <clinit>");
-	    /* Apart invokespecial, can't invoke <init> */
+
+	    /* Apart from invokespecial, can't invoke <init>.  */
 	    if (op_code != OPCODE_invokespecial && ID_INIT_P (method_name))
 	      VERIFICATION_ERROR ("invoke opcode can't invoke <init>");
 
@@ -1060,11 +1128,14 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 		  if (!nargs || notZero)
 		      VERIFICATION_ERROR 
 		        ("invalid argument number in invokeinterface");
+
 		  /* If we verify/resolve the constant pool, as we should,
 		     this test (and the one just following) are redundant.  */
 		  if (! self_is_interface)
-		    VERIFICATION_ERROR ("invokeinterface calls method not in interface");
+		    VERIFICATION_ERROR
+                      ("invokeinterface calls method not in interface");
 		  break;
+
 		default:
 		  if (self_is_interface)
 		    VERIFICATION_ERROR ("method in interface called");
@@ -1077,9 +1148,9 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	  }
 
 	case OPCODE_arraylength:
-	    /* Type checking actually made during code generation */
-	    pop_type( ptr_type_node );
-	    PUSH_TYPE( int_type_node );
+	    /* Type checking actually made during code generation.  */
+	    pop_type (ptr_type_node);
+	    PUSH_TYPE (int_type_node);
 	    break;
 	    
         /* Q&D verification *or* more checking done during code generation
@@ -1093,8 +1164,9 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	case OPCODE_bastore: type = int_type_node; goto astore;
 	case OPCODE_castore: type = int_type_node; goto astore;
 	case OPCODE_sastore: type = int_type_node; goto astore;
+
 	astore:
-	  /* FIXME - need better verification here */
+	  /* FIXME - need better verification here.  */
 	  pop_type (type);	     /* new value */
 	  pop_type (int_type_node);  /* index */
 	  pop_type (ptr_type_node);  /* array */
@@ -1110,6 +1182,7 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	case OPCODE_baload: type = promote_type (byte_type_node);  goto aload;
 	case OPCODE_caload: type = promote_type (char_type_node);  goto aload;
 	case OPCODE_saload: type = promote_type (short_type_node); goto aload;
+
         aload:
 	  pop_type (int_type_node);
 	  tmp = pop_type (ptr_type_node);
@@ -1135,9 +1208,9 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	newarray:
 	  if (int_value >= 0 && prevpc >= 0)
 	    {
-	      /* If previous instruction pushed int constant,
+	      /* If the previous instruction pushed an int constant,
 		 we want to use it. */
-	      switch (byte_ops[prevpc])
+	      switch (byte_ops [prevpc])
 		{
 		case OPCODE_iconst_0: case OPCODE_iconst_1:
 		case OPCODE_iconst_2: case OPCODE_iconst_3:
@@ -1151,6 +1224,7 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	    }
 	  else
 	    int_value = -1;
+
 	  type = build_java_array_type (type, int_value);
 	  pop_type (int_type_node);
 	  PUSH_TYPE (type);
@@ -1162,11 +1236,13 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	    index = IMMEDIATE_u2;
 	    ndim  = IMMEDIATE_u1;
 
-            if( ndim < 1 )
-              VERIFICATION_ERROR ("number of dimension lower that 1 in multianewarray" );
+            if (ndim < 1)
+              VERIFICATION_ERROR
+                ("number of dimension lower that 1 in multianewarray" );
 
-	    for( i = 0; i < ndim; i++ )
+	    for (i = 0; i < ndim; i++)
 	      pop_type (int_type_node);
+
 	    PUSH_TYPE (get_class_constant (current_jcf, index));
 	    break;
 	  }
@@ -1176,7 +1252,7 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	  break;
 
 	case OPCODE_athrow:
-	  /* FIXME: athrow also empties the stack. */
+	  /* FIXME: athrow also empties the stack.  */
 	  POP_TYPE (throwable_type_node, "missing throwable at athrow" );
 	  INVALIDATE_PC;
 	  break;
@@ -1187,6 +1263,7 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	  type = get_class_constant (current_jcf, IMMEDIATE_u2);
 	  PUSH_TYPE (type);
 	  break;
+
 	case OPCODE_instanceof:
 	  POP_TYPE (object_ptr_type_node,
 		    "instanceof operand is not a pointer");
@@ -1199,12 +1276,14 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	    jint low, high;
 
 	    POP_TYPE (int_type_node, "missing int for tableswitch");
+
 	    while (PC%4)
 	      {
-	        if (byte_ops[PC++])
+	        if (byte_ops [PC++])
 		  VERIFICATION_ERROR ("bad alignment in tableswitch pad");
 	      }
-	    PUSH_PENDING (lookup_label (oldpc+IMMEDIATE_s4));
+
+	    PUSH_PENDING (lookup_label (oldpc + IMMEDIATE_s4));
 	    low  = IMMEDIATE_s4;
 	    high = IMMEDIATE_s4;
 
@@ -1213,6 +1292,7 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 
 	    while (low++ <= high)
 	      PUSH_PENDING (lookup_label (oldpc + IMMEDIATE_s4));
+
 	    INVALIDATE_PC;
 	    break;
 	  }
@@ -1222,13 +1302,14 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	    jint npairs, last = 0, not_registered = 1;
 
 	    POP_TYPE (int_type_node, "missing int for lookupswitch");
+
 	    while (PC%4)
 	      {
-	        if (byte_ops[PC++])
+	        if (byte_ops [PC++])
 		  VERIFICATION_ERROR ("bad alignment in lookupswitch pad");
 	      }
 
-	    PUSH_PENDING (lookup_label (oldpc+IMMEDIATE_s4));
+	    PUSH_PENDING (lookup_label (oldpc + IMMEDIATE_s4));
 	    npairs = IMMEDIATE_s4;
 	    
 	    if (npairs < 0)
@@ -1237,6 +1318,7 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	    while (npairs--)
 	      {
 	        int match = IMMEDIATE_s4;
+
 		if (not_registered)
 		  not_registered = 0;
 		else if (last >= match)
@@ -1273,13 +1355,16 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 		int nlocals = DECL_MAX_LOCALS (current_function_decl);
 		index = nlocals + DECL_MAX_STACK (current_function_decl);
 		return_type_map = make_tree_vec (index);
+
 		while (index > nlocals)
 		  TREE_VEC_ELT (return_type_map, --index) = TYPE_UNKNOWN;
+
 		while (index > 0)
 		  TREE_VEC_ELT (return_type_map, --index) = TYPE_UNUSED;
+
 		LABEL_RETURN_LABEL (target)
 		  = build_decl (LABEL_DECL, NULL_TREE, TREE_TYPE (target));
-		LABEL_PC (LABEL_RETURN_LABEL (target)) = -1;
+		LABEL_PC (LABEL_RETURN_LABEL (target)) = INVALID_PC;
 		LABEL_RETURN_TYPE_STATE (target) = return_type_map;
 		LABEL_IS_SUBR_START (target) = 1;
 		LABEL_IN_SUBR (target) = 1;
@@ -1315,7 +1400,7 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 		while (--len >= 0)
 		  {
 		    if (TREE_VEC_ELT (return_map, len) != TYPE_UNUSED)
-		      type_map[len] = TREE_VEC_ELT (return_map, len);
+		      type_map [len] = TREE_VEC_ELT (return_map, len);
 		  }
 		current_subr = LABEL_SUBR_CONTEXT (target);
 		if (RETURN_MAP_ADJUSTED (return_map))
@@ -1325,33 +1410,37 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 	    INVALIDATE_PC;
 	  }
 	  break;
+
 	case OPCODE_ret:
-	  if (current_subr == NULL)
+	  if (current_subr == NULL_TREE)
 	    VERIFICATION_ERROR ("ret instruction not in a jsr subroutine");
 	  else
 	    {
 	      tree ret_map = LABEL_RETURN_TYPE_STATE (current_subr);
-	      int size = DECL_MAX_LOCALS(current_function_decl)+stack_pointer;
+	      int size
+                = DECL_MAX_LOCALS (current_function_decl) + stack_pointer;
 	      index = wide ? IMMEDIATE_u2 : IMMEDIATE_u1;
 	      wide = 0;
 	      INVALIDATE_PC;
 	      if (index < 0 || index >= DECL_MAX_LOCALS (current_function_decl)
-		  || type_map[index] != TYPE_RETURN_ADDR)
+		  || type_map [index] != TYPE_RETURN_ADDR)
 		VERIFICATION_ERROR ("invalid ret index");
 
 	      /* The next chunk of code is similar to an inlined version of
-	       *     merge_type_state (LABEL_RETURN_LABEL (current_subr)).
-	       * The main differences are that LABEL_RETURN_LABEL is
-	       * pre-allocated by the jsr (but we don't know the size then);
-	       * and that we have to handle TYPE_UNUSED. */
+               merge_type_state (LABEL_RETURN_LABEL (current_subr)).
+	       The main differences are that LABEL_RETURN_LABEL is
+	       pre-allocated by the jsr (but we don't know the size then);
+	       and that we have to handle TYPE_UNUSED.  */
 
 	      if (! RETURN_MAP_ADJUSTED (ret_map))
-		{ /* First return from this subroutine - fix stack pointer. */
+		{
+                  /* First return from this subroutine - fix stack
+                  pointer.  */
 		  TREE_VEC_LENGTH (ret_map) = size;
 		  for (index = size;  --index >= 0; )
 		    {
 		      if (TREE_VEC_ELT (ret_map, index) != TYPE_UNUSED)
-			TREE_VEC_ELT (ret_map, index) = type_map[index];
+			TREE_VEC_ELT (ret_map, index) = type_map [index];
 		    }
 		  RETURN_MAP_ADJUSTED (ret_map) = 1;
 		}
@@ -1377,10 +1466,9 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 			}
 		    }
 		}
-
-
             }
           break;
+
         case OPCODE_jsr_w:        
         case OPCODE_ret_w:
         default:
@@ -1393,17 +1481,18 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
       /* The following test is true if we have entered or exited an exception
 	 handler range *or* we have done a store to a local variable.
 	 In either case we need to consider any exception handlers that
-	 might "follow" this instruction. */
+	 might "follow" this instruction.  */
 
       if (eh_ranges != prev_eh_ranges)
 	{
 	  int save_stack_pointer = stack_pointer;
 	  int index = DECL_MAX_LOCALS (current_function_decl);
-	  tree save_type = type_map[index];
+	  tree save_type = type_map [index];
 	  tree save_current_subr = current_subr;
 	  struct eh_range *ranges = find_handler (oldpc);
 	  stack_pointer = 1;
-	  for (; ranges != NULL_EH_RANGE;  ranges = ranges->outer)
+
+	  for ( ; ranges != NULL_EH_RANGE; ranges = ranges->outer)
 	    {
 	      tree chain = ranges->handlers;
 
@@ -1420,7 +1509,7 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 		 have that the current_subr is entirely within the catch range.
 		 In that case we can assume if that if a caller (the jsr) of
 		 a subroutine is within the catch range, then the handler is
-		 *not* part of the subroutine, and vice versa. */
+		 *not* part of the subroutine, and vice versa.  */
 
 	      current_subr = save_current_subr;
 	      for ( ; current_subr != NULL_TREE;
@@ -1428,31 +1517,35 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
 		{
 		  tree return_labels = LABEL_RETURN_LABELS (current_subr);
 		  /* There could be multiple return_labels, but
-		     we only need to check one. */
+		     we only need to check one.  */
 		  int return_pc = LABEL_PC (TREE_VALUE (return_labels));
 		  if (return_pc <= ranges->start_pc
 		      || return_pc > ranges->end_pc)
 		    break;
 		}
 
-	      for ( ;  chain != NULL_TREE;  chain = TREE_CHAIN (chain))
+	      for ( ; chain != NULL_TREE; chain = TREE_CHAIN (chain))
 		{
 		  tree handler = TREE_VALUE (chain);
 		  tree type = TREE_PURPOSE (chain);
+
 		  if (type == NULL_TREE)  /* a finally handler */
 		    type = throwable_type_node;
-		  type_map[index] = promote_type (type);
+
+		  type_map [index] = promote_type (type);
 
 		  PUSH_PENDING (handler);
 		}
 	    }
 	  stack_pointer = save_stack_pointer;
 	  current_subr = save_current_subr;
-	  type_map[index] = save_type;
+	  type_map [index] = save_type;
 	  prev_eh_ranges = eh_ranges;
 	}
     }
+
   return 1;
+
  pop_type_error:
   error ("verification error at PC=%d", oldpc);
   if (message != NULL)
@@ -1460,16 +1553,20 @@ verify_jvm_instructions (JCF* jcf, const unsigned char *byte_ops, long length)
   error ("%s", pmessage);
   free (pmessage);
   return 0;
+
  stack_overflow:
   message = "stack overflow";
   goto verify_error;
+
  bad_pc:
   message = "program counter out of range";
   goto verify_error;
+
  error_with_index:
   error ("verification error at PC=%d", oldpc);
   error (message, index);
   return 0;
+
  verify_error:
   error ("verification error at PC=%d", oldpc);
   error ("%s", message);