Re: Patch: jcf-write and last_bc

[Per Bothner <per at bothner dot com>]

The checked in the following patch.

2001-10-11  Per Bothner  <per@bothner.com>

    * parse.y (patch_synchronized_statement):  Use a TRY_FINALLY_EXPR
    rather than a CLEANUP_POINT_EXPR/WITH_CLEANUP_EXPR pair.
    The former is simpler, and jcf-write.c handles it better.
    (java_complete_lhs):  No longer need to handle CLEANUP_POINT_EXPR
    or WITH_CLEANUP_EXPR.
    * jcf-write.c:  Revert Alex's change from 2000-10-18.  It is no
    longer needed, as we already handle empty TRY_FINALLY_EXPR bodies fine.

>------------------------------------------------------------------------
>
>Index: parse.y
>===================================================================
>RCS file: /cvs/gcc/gcc/gcc/java/parse.y,v
>retrieving revision 1.318
>diff -u -p -r1.318 parse.y
>--- parse.y	2001/10/09 05:40:35	1.318
>+++ parse.y	2001/10/10 00:02:47
>@@ -11579,21 +11579,6 @@ java_complete_lhs (node)
>       TREE_TYPE (node) = TREE_TYPE (TREE_OPERAND (node, 0));
>       return node;
> 
>-    case CLEANUP_POINT_EXPR:
>-      COMPLETE_CHECK_OP_0 (node);
>-      TREE_TYPE (node) = void_type_node;
>-      CAN_COMPLETE_NORMALLY (node) = 
>-	CAN_COMPLETE_NORMALLY (TREE_OPERAND (node, 0));
>-      return node;
>-
>-    case WITH_CLEANUP_EXPR:
>-      COMPLETE_CHECK_OP_0 (node);
>-      COMPLETE_CHECK_OP_1 (node);
>-      CAN_COMPLETE_NORMALLY (node) = 
>-	CAN_COMPLETE_NORMALLY (TREE_OPERAND (node, 0));
>-      TREE_TYPE (node) = void_type_node;
>-      return node;
>-
>     case LABELED_BLOCK_EXPR:
>       PUSH_LABELED_BLOCK (node);
>       if (LABELED_BLOCK_BODY (node))
>@@ -15668,13 +15667,9 @@ patch_synchronized_statement (node, wfl_
>   CAN_COMPLETE_NORMALLY (exit) = 1;
>   assignment = build (MODIFY_EXPR, NULL_TREE, expr_decl, expr);
>   TREE_SIDE_EFFECTS (assignment) = 1;
>-  node = build1 (CLEANUP_POINT_EXPR, NULL_TREE,
>-		 build (COMPOUND_EXPR, NULL_TREE,
>-			build (WITH_CLEANUP_EXPR, NULL_TREE,
>-			       build (COMPOUND_EXPR, NULL_TREE,
>-				      assignment, enter),
>-			       exit, NULL_TREE),
>-			block));
>+  node = build (COMPOUND_EXPR, NULL_TREE,
>+		build (COMPOUND_EXPR, NULL_TREE, assignment, enter),
>+		build (TRY_FINALLY_EXPR, NULL_TREE, block, exit));
>   node = build_expr_block (node, expr_decl);
> 
>   return java_complete_tree (node);
>Index: jcf-write.c
>===================================================================
>RCS file: /cvs/gcc/gcc/gcc/java/jcf-write.c,v
>retrieving revision 1.90
>diff -u -p -r1.90 jcf-write.c
>--- jcf-write.c	2001/10/08 20:35:03	1.90
>+++ jcf-write.c	2001/10/10 00:36:12
>@@ -57,7 +57,7 @@ char *jcf_write_base_directory = NULL;
> /* Add a 1-byte instruction/operand I to bytecode.data,
>    assuming space has already been RESERVE'd. */
> 
>-#define OP1(I) (state->last_bc = *state->bytecode.ptr++ = (I), CHECK_OP(state))
>+#define OP1(I) (*state->bytecode.ptr++ = (I), CHECK_OP(state))
> 
> /* Like OP1, but I is a 2-byte big endian integer. */
> 
>@@ -275,8 +275,6 @@ struct jcf_partial
> 
>   /* Information about the current switch statement. */
>   struct jcf_switch_state *sw_state;
>-
>-  enum java_opcode last_bc;	/* The last emitted bytecode */
> };
> 
> static void generate_bytecode_insns PARAMS ((tree, int, struct jcf_partial *));
>@@ -2167,16 +2165,7 @@ generate_bytecode_insns (exp, target, st
> 	tree src = TREE_OPERAND (exp, 0);
> 	tree src_type = TREE_TYPE (src);
> 	tree dst_type = TREE_TYPE (exp);
>-	/* Detect the situation of compiling an empty synchronized
>-	   block.  A nop should be emitted in order to produce
>-	   verifiable bytecode. */
>-	if (exp == empty_stmt_node
>-	    && state->last_bc == OPCODE_monitorenter
>-	    && state->labeled_blocks
>-	    && state->labeled_blocks->pc == PENDING_CLEANUP_PC)
>-	  OP1 (OPCODE_nop);
>-	else
>-	  generate_bytecode_insns (TREE_OPERAND (exp, 0), target, state);
>+	generate_bytecode_insns (TREE_OPERAND (exp, 0), target, state);
> 	if (target == IGNORE_TARGET || src_type == dst_type)
> 	  break;
> 	if (TREE_CODE (dst_type) == POINTER_TYPE)
>