[Bug java/16431] New: Bytecode compiler silently generates incorrect code

[Bug java/16431] New: Bytecode compiler silently generates incorrect code

[aph at gcc dot gnu dot org]

With some oddly formed class files, the bytecode compiler can spuriously
generate additional DECLs for local variable slots, and these DECLs have
undefined initial values.  This is a regression caused by the tree-SSA merge.

The problem arises when there are two different types put onto the stack at
different points in the execution.  This generates two DECLs, one for each type.
 Later code that refers to that stack item can do so with a type that is a
common superclass of the two types, but we have generated two separate DECLs.

The only way properly to fix this is to change the way that stack items are
mapped on to DECLs.

-- 
           Summary: Bytecode compiler silently generates incorrect code
           Product: gcc
           Version: 3.5.0
            Status: UNCONFIRMED
          Severity: critical
          Priority: P1
         Component: java
        AssignedTo: aph at gcc dot gnu dot org
        ReportedBy: aph at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org,java-prs at gcc dot gnu
                    dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16431

[Bug java/16431] Bytecode compiler silently generates incorrect code

[aph at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-07-08 10:19:41
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16431

[Bug java/16431] [3.5 Regression] Bytecode compiler silently generates incorrect code

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-07-08 10:25 -------
I think there was a message to gcc@ about this.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code
   Last reconfirmed|2004-07-08 10:19:41         |2004-07-08 10:25:20
               date|                            |
            Summary|Bytecode compiler silently  |[3.5 Regression] Bytecode
                   |generates incorrect code    |compiler silently generates
                   |                            |incorrect code
   Target Milestone|---                         |3.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16431

[Bug java/16431] [3.5 Regression] Bytecode compiler silently generates incorrect code

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-07-21 16:12 -------
Subject: Bug 16431

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	aph@gcc.gnu.org	2004-07-21 16:12:33

Modified files:
	gcc/java       : ChangeLog 

Log message:
	PR java/16431.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/java/ChangeLog.diff?cvsroot=gcc&r1=1.1420&r2=1.1421



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16431

[Bug java/16431] [3.5 Regression] Bytecode compiler silently generates incorrect code

[aph at gcc dot gnu dot org]

------- Additional Comments From aph at gcc dot gnu dot org  2004-07-21 16:13 -------
2004-07-20  Andrew Haley  <aph@redhat.com>

	PR java/16431.
	* verify.c (verify_jvm_instructions): Comment change only.

	* typeck.c (build_java_array_type): Add size field to array name.

	* java-tree.h (LOCAL_SLOT_P): New.
	(update_aliases): Add PC argument.
	(pushdecl_function_level): New function.

	* java-gimplify.c (java_gimplify_expr): Handle VAR_DECL,
	MODIFY_EXPR, and SAVE_EXPR.
	(java_gimplify_modify_expr): New function.

	* expr.c (push_type_0): Call find_stack_slot() to create temporary.
	(expand_iinc): Pass PC to update_aliases().
	(STORE_INTERNAL): Likewise.
	(process_jvm_instruction): Likewise.

	* decl.c (base_decl_map): New variable.
	(uniq): New variable.
	(update_aliases): Rewrite with more thorough checking.
	(debug_variable_p): New function.
	(push_jvm_slot): Don't initialize local variable.  Don't pushdecl.
	(check_local_named_variable): Delete whole function.
	(initialize_local_variable): New function.
	(check_local_unnamed_variable): Add checks and comments.
	(find_local_variable): Rewrite.
	(java_replace_reference): New function.
	(function_binding_level): New variable.
	(pushdecl_function_level): New function.
	(maybe_pushlevels): Set DECL_LOCAL_END_PC.
	(maybe_pushlevels): Call pushdecl() on each of the new decls.
	(start_java_method): Reset uniq.  Create base_decl_map.  Set
	function_binding_level.
	(end_java_method): Null unused fields to save memory.


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16431

[Bug java/16431] [3.5 Regression] Bytecode compiler silently generates incorrect code

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-08-09 00:36 -------
*** Bug 16188 has been marked as a duplicate of this bug. ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bonniot at users dot sf dot
                   |                            |net


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16431