Thread

1. compiler warning

   Bruce Momjian <bruce@momjian.us> — 2011-02-03T03:40:11Z

   I am seeing the following compiler warning for the past few days:
   
   	basebackup.c:213: warning: variable `ptr' might be clobbered by
   	`longjmp' or `vfork'
   
   and I see this comment in the file:
   
   	/*
   	 * Actually do a base backup for the specified tablespaces.
   	 *
   	 * This is split out mainly to avoid complaints about "variable might be
   	 * clobbered by longjmp" from stupider versions of gcc.
   	 */
   
   Seems that isn't working as expected.  I am using:
   
   	gcc version 2.95.3 20010315 (release)
   
   with -O1.
   
   -- 
     Bruce Momjian  <bruce@momjian.us>        http://momjian.us
     EnterpriseDB                             http://enterprisedb.com
   
     + It's impossible for everything to be true. +
   
   

2. Re: compiler warning

   Magnus Hagander <magnus@hagander.net> — 2011-02-03T08:22:13Z

   On Thu, Feb 3, 2011 at 04:40, Bruce Momjian <bruce@momjian.us> wrote:
   > I am seeing the following compiler warning for the past few days:
   >
   >        basebackup.c:213: warning: variable `ptr' might be clobbered by
   >        `longjmp' or `vfork'
   >
   > and I see this comment in the file:
   >
   >        /*
   >         * Actually do a base backup for the specified tablespaces.
   >         *
   >         * This is split out mainly to avoid complaints about "variable might be
   >         * clobbered by longjmp" from stupider versions of gcc.
   >         */
   >
   > Seems that isn't working as expected.  I am using:
   >
   >        gcc version 2.95.3 20010315 (release)
   >
   > with -O1.
   
   This is the same warning Tom fixed earlier. I have no idea what
   actually causes it :(
   
   I think it's somehow caused by the PG_ENSURE_ERROR_CLEANUP  stuff.
   Does it go away if you break everything inside the if
   (opt->includewal) into it's own function? (Or at least everything
   except the pq_putemptymessage() call, because moving that would make
   the code very confusing)
   
   
   -- 
    Magnus Hagander
    Me: http://www.hagander.net/
    Work: http://www.redpill-linpro.com/
   
   

3. Re: compiler warning

   Bruce Momjian <bruce@momjian.us> — 2011-02-05T04:28:57Z

   Magnus Hagander wrote:
   > On Thu, Feb 3, 2011 at 04:40, Bruce Momjian <bruce@momjian.us> wrote:
   > > I am seeing the following compiler warning for the past few days:
   > >
   > > ? ? ? ?basebackup.c:213: warning: variable `ptr' might be clobbered by
   > > ? ? ? ?`longjmp' or `vfork'
   > >
   > > and I see this comment in the file:
   > >
   > > ? ? ? ?/*
   > > ? ? ? ? * Actually do a base backup for the specified tablespaces.
   > > ? ? ? ? *
   > > ? ? ? ? * This is split out mainly to avoid complaints about "variable might be
   > > ? ? ? ? * clobbered by longjmp" from stupider versions of gcc.
   > > ? ? ? ? */
   > >
   > > Seems that isn't working as expected. ?I am using:
   > >
   > > ? ? ? ?gcc version 2.95.3 20010315 (release)
   > >
   > > with -O1.
   > 
   > This is the same warning Tom fixed earlier. I have no idea what
   > actually causes it :(
   > 
   > I think it's somehow caused by the PG_ENSURE_ERROR_CLEANUP  stuff.
   > Does it go away if you break everything inside the if
   > (opt->includewal) into it's own function? (Or at least everything
   > except the pq_putemptymessage() call, because moving that would make
   > the code very confusing)
   
   I added the attached C comment so we know why the warning is generated. 
   We can remove it later if we want, but I want to have it if we get
   reports about 9.1 problems.
   
   -- 
     Bruce Momjian  <bruce@momjian.us>        http://momjian.us
     EnterpriseDB                             http://enterprisedb.com
   
     + It's impossible for everything to be true. +