[RFA-v2] Avoid invalid parameter warnings in C runtime function for mingw built GDB

["Pierre Muller" <pierre.muller@ics-cnrs.unistra.fr>]

  I followed Eli's advice to go with Tom's suggestion.

> -----Message d'origine-----
> De : gdb-patches-owner@sourceware.org [mailto:gdb-patches-
> owner@sourceware.org] De la part de Tom Tromey
> Envoyé : mardi 13 août 2013 17:38
> À : Pierre Muller
> Cc : 'Eli Zaretskii'; gdb-patches@sourceware.org
> Objet : Re: [RFC] Avoid invalid parameter warnings in C runtime function
for
> mingw builtr GDB
> 
> >>>>> "Pierre" == Pierre Muller <pierre.muller@ics-cnrs.unistra.fr>
writes:
> 
> Pierre>   Once again, my insufficient C knowledge is to blame...
> Pierre> Would that be correct?
> 
> Pierre> #if O_CLOEXEC
> Pierre>   static int fopen_e_ever_failed = 0;
> Pierre> #else
> Pierre>   static int fopen_e_ever_failed = 1;
> Pierre> #endif
> 
> O_CLOEXEC is unconditionally defined earlier.
> But you can just write:
> 
>   /* If we provide a fake O_CLOEXEC, then don't ever try "e".  */
>   static int fopen_e_ever_failed = O_CLOEXEC == 0;

Is this OK to commit?
Maybe some comments on the ChangeLog entry?


Pierre Muller


2013-08-14  Pierre Muller  <muller@sourceware.org>
	    Tom Tromey  <tromey@redhat.com>

	* common/filestuff.c (gdb_fopen_cloexec): Do not try to use "e"
	mode if operating system doesn't know O_CLOEXEC, this allows to
	avoid getting a output debug string warning for mingw hosted
	GDB executables.


Index: src/gdb/common/filestuff.c
===================================================================
RCS file: /cvs/src/src/gdb/common/filestuff.c,v
retrieving revision 1.7
diff -u -p -r1.7 filestuff.c
--- src/gdb/common/filestuff.c	26 Jun 2013 08:01:55 -0000	1.7
+++ src/gdb/common/filestuff.c	14 Aug 2013 09:44:40 -0000
@@ -311,7 +311,9 @@ FILE *
 gdb_fopen_cloexec (const char *filename, const char *opentype)
 {
   FILE *result = NULL;
-  static int fopen_e_ever_failed;
+  /* If O_CLOEXEC is zero, the operating system doesn't
+     know about close on exec mode "e", so don't even try to use it.  */
+  static int fopen_e_ever_failed = O_CLOEXEC == 0;
 
   if (!fopen_e_ever_failed)
     {