c++/4092: Use of ANSI features in gcc/cp/class.c

[rkl at connect dot org dot uk]

>Number:         4092
>Category:       c++
>Synopsis:       Use of ANSI features in gcc/cp/class.c
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Aug 23 07:06:01 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator:     rkl@connect.org.uk
>Release:        gcc 3.0.1
>Organization:
>Environment:
HP-UX 11.00, but applies to all platforms
>Description:
In gcc/cp/class.c, there's a few places where ANSI C
constructs are used, which prevents the source being
compiled with a K&R compiler (which you do need to do
for this file):

Line 2382 (end of finish_struct_methods() function):

    qsort (&TREE_VEC_ELT (method_vec, slot), len-slot, sizeof (tree),
           (int (*)(const void *, const void *))method_name_cmp);

(the function prototype for method_name_cmp causes a K&R C
compiler to bomb out)

Line 5463 (middle of finish_struct_1() function):

      qsort (&TREE_VEC_ELT (field_vec, 0), n_fields, sizeof (tree),
             (int (*)(const void *, const void *))field_decl_cmp);

(same problem as the one above)

Line 4018 (layout_nonempty_base_or_field):

      struct record_layout_info_s old_rli = *rli;

(this assignment is illegal in K&R C)
>How-To-Repeat:
Build gcc 3.0.1 with a strictly K&R C compiler - you can
use the "standard" cc in HP-UX (or the HP-UX ANSI C with
CFLAGS="-Ac") to reproduce this. On a side note, it appears
to me that the gcc team don't actually do this - there
are other instances of K&R-illegal code in gcc 3.0.1 as
well (if I get the time, I'll file them, but this bug
should hopefully spark the developers to fix them all).

Not allowing
K&R C compilers to build gcc 3.X is quite poor, IMHO,
especially since you could with 2.95.3.
>Fix:
Conditionalise the statements with "#ifdef __STDC__" - for
example, the first one in my source now reads:

    qsort (&TREE_VEC_ELT (method_vec, slot), len-slot, sizeof (tree),
#ifdef __STDC__
           (int (*)(const void *, const void *))method_name_cmp);
#else
           method_name_cmp);
#endif
>Release-Note:
>Audit-Trail:
>Unformatted: