Re: standards/47119: putc_unlocked(3) is found even with -std=c89

[christos%zoulas.com@localhost (Christos Zoulas)]

On Oct 24,  2:10pm, sdaoden%gmail.com@localhost (Steffen "Daode" Nurpmeso) 
wrote:
-- Subject: Re: standards/47119: putc_unlocked(3) is found even with -std=c89

| The following reply was made to PR standards/47119; it has been noted by 
GNATS.
| 
| From: Steffen "Daode" Nurpmeso <sdaoden%gmail.com@localhost>
| To: Martin Husemann <martin%duskware.de@localhost>
| Cc: gnats-bugs%NetBSD.org@localhost
| Subject: Re: standards/47119: putc_unlocked(3) is found even with -std=c89
| Date: Wed, 24 Oct 2012 16:05:07 +0200
| 
|  Martin Husemann <martin%duskware.de@localhost> wrote:
|  
|   |On Wed, Oct 24, 2012 at 03:11:03PM +0200, Steffen Daode Nurpmeso wrote:
|   |> Because it is not part of C89/C99?
|   |
|   |You are misunderstanding the compiler option - it has no influence on the
|   |symbols visible in libraries nor system headers (at least in general).
|   |There are a few defines you can add via -D to make the headers pollute less
|  
|  Hmm.  I think you're right.
|  Well i'm not really working with those headers, and i still see
|  a '#define _GNU_SOURCE' on top of the one that's really important
|  for me.
|  
|   |namespace, but since this is a posix blessed function, it is better
|   |to avoid a name clash in application code.
|   |Martin
|  
|  Yes, a lot of conditions and a lot of what standards produce most
|  of the time, so thanks for all those work on standard compliance.
|  
|  Nonetheless - the bug is triggered only with -std=c89, and only on
|  NetBSD 6.0.  And in the meanwhile i've found it.
|  In fact it has nothing to do with putc_unlocked() (i was so clumsy
|  that i even tried to compile with -pthread and -D_REENTRANT, and
|  it was still expanded to __sputc() or so - amazing!), but it is in
|  fact alloca(3) that returns an invalid buffer:
|  
|    %fwrite_td() calls ac_alloc for 29
|    fwrite_td() calls memcpy (From: <XXXXXXXXXXX%YYYY.com@localhost>
|    )29
|    fwrite_td() before delctrl (^])29
|    fwrite_td() calls prefixwrite (^])29
|    *29 (0xbfbf9254)()*^@^@^@^@^@^@^@^@XXXXXXXXXX%YYYY.com@localhost>
|  
|  From the alloca(3) manual i see nothing special to adhere to,
|  i would not describe 29 bytes as a "large unbounded allocation".
|  The CFLAGS are simply '-std=c89 -O2', so nothing special at all.
|  I think this is worth another PR?

You are probably missing some include header (stdlib.h) and there
is no prototype for alloca()? Post the code...

christos