[C++ PATCH] BLOCK_VARS and tag_transparent level

[Devang Patel <dpatel at apple dot com>]

If type of a local variable has non-trival destructor then
'tag_transparent' level is pushed to take care of clean up.
Now during poplevel we need to merge BLOCK_VARS from this
transparent level into outer level. Without this, in following
example debugging info will put variables 'a', 'b' and 'c'
in different blocks.

template <class T> class my_stack {
  T* v;
public:
  my_stack () { }
  ~my_stack () { }
};

typedef my_stack<int> TS;
TS ts;

void foo()
{
        long  s = 0;
        {
                unsigned long a = 0;
                switch (a)
                {
                        case 0: break;
                        default: break;
                }
                my_stack<int> b;
                int c = -1;
                while (c < a)
                {
                        int d;
                        c++;
                }
        }
}

Bootstrapped and tested. Did not find any new gdb regression
(for stabs and dwarf) on x86-linux. I gave this example to
our local gdb guys, so hopefully it will show up in FSF gdb
test suite some day.

2002-07-24  Devang Patel  <dpatel@apple.com>

        * decl.c (poplevel): Merge BLOCK_VARS from tag_transparent 
level.


OK to commit ?
Thank you,
--
Devang

Index: decl.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/decl.c,v
retrieving revision 1.1096
diff -Idpatel.pbxuser -c -3 -p -r1.1096 decl.c
*** decl.c      22 Jul 2003 23:30:14 -0000      1.1096
--- decl.c      24 Jul 2003 22:07:38 -0000
*************** poplevel (int keep, int reverse, int fun
*** 1521,1526 ****
--- 1521,1527 ----
    if (tmp == 2)
      {
        tree scope_stmts;
+       tree saved_block;

        scope_stmts
        = add_scope_stmt (/*begin_p=*/0, /*partial_p=*/1);
*************** poplevel (int keep, int reverse, int fun
*** 1530,1536 ****
--- 1531,1545 ----
          SCOPE_STMT_BLOCK (TREE_VALUE (scope_stmts)) = block;
        }

+       if (block)
+       saved_block = block;
+
        block = poplevel (keep, reverse, functionbody);
+
+       /* Merge BLOCK_VARS from tag_transparent block into current
+        block.  */
+       BLOCK_VARS (block) = chainon (BLOCK_VARS (block), BLOCK_VARS 
(saved_block));
+       BLOCK_VARS (saved_block) = NULL_TREE;
      }

    POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, block);