From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 17749 invoked by alias); 20 Sep 2002 07:36:50 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 17742 invoked from network); 20 Sep 2002 07:36:49 -0000 Received: from unknown (HELO satan.diablo.localnet) (64.164.47.8) by sources.redhat.com with SMTP; 20 Sep 2002 07:36:49 -0000 Received: from p by satan.diablo.localnet with local (Exim 3.35 #1 (Debian)) id 17sILJ-0005U4-00 for ; Fri, 20 Sep 2002 00:36:49 -0700 Date: Fri, 20 Sep 2002 00:36:00 -0000 To: Gdb Mailing List Subject: question about conditional breaking Message-ID: <20020920073648.GA21072@dirac.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4i From: Peter Jay Salzman X-SW-Source: 2002-09/txt/msg00304.txt.bz2 dear gdb mailing list, the gdb user's manual doesn't have a lot to say about conditional breaking, but i think i'm beginning to understand it more thoroughly. first, we know that the boolean expressions you'd expect to be able to use, work as advertised. break 1 if x > 0 break 2 if y <= x parenthesis seem to be purely optional. break 3 if (! x >= -1) but there seems to be more to the story. you can use functions too. here's a test program: #include int main(void) { double l = cos(i); double m = y0(i); return 0; } where y0 is a bessel function of the 2nd kind (a von neumann function) of the zeroth order. it seems like you can use functions, like math library functions. but with a privisio: (gdb) break main if cos(3) == 0 Breakpoint 1 at 0x8048456: file math.c, line 5. (gdb) break main if sin(3) == 0 No symbol "sin" in current context. (gdb) break main if exp(3) == 0 No symbol "exp" in current context. (gdb) break main if y0(3) == 0 Note: breakpoint 1 also set at pc 0x8048456. Breakpoint 2 at 0x8048456: file math.c, line 5. (gdb) break main if y1(3) == 0 No symbol "y1" in current context. so it appears that here's the rule: you're allowed to use any function, even library functions, provided that: 1. the library is linked to your application 2. you actually _use_ the function somewhere in your code. to be honest, i'm not the least surprised by condition 1, but i'm shocked by condition 2. does anyone have anything to add to this? am i on the right track here? pete -- Fingerprint: B9F1 6CF3 47C4 7CD8 D33E 70A9 A3B9 1945 67EA 951D