[Bug threads/8980] parse error while setting thread specific breakpoint

["fethikaval at hotmail dot com" <sourceware-bugzilla at sourceware dot org>]

------- Additional Comments From fethikaval at hotmail dot com  2009-12-21 22:20 -------
Does anyone know whether this one is fixed or not?

Ýt causes serious functionality unuse for multi-threaded SW.

(In reply to comment #0)
> [Converted from Gnats 1875]
> 
> I tried to insert thread specific breakpoints in the following format
> 
> break *0x<address> thread <threadno> if <condition>
> 
> and I get the following parse error
> 
> A parse error in expression, near `thread 2'.
> 
> While I am able to set breakpoints that include other SAL specification like
<source file:line no> and symbol name, this particular case gives me the error.
> 
> I looked at the code and it assumes whatever that follows after the address is
a C expression. It tries to parse it and fails. Other SAL specification types do
not make this assumption and look for "thread" keyword before parsing the rest
of the string.
> 
> The gdb info page says that it accepts all types of SAL specification while
setting a thread specific breakpoint. So I assume that either the documentation
is incorrect, or the functionality is not achieved.
> 
> I took a simple pthread program as below:
> 
> #include <stdio.h>
> #include <pthread.h>
> #include <sys/types.h>
> #include <unistd.h>
> #include <linux/unistd.h>
> 
> _syscall0(pid_t,gettid)
> 
> #define NUM_THREADS 4
> 
> void *count() {
> 	int i;
> 	int cur_thr_id = 0;
> 	
> 	cur_thr_id = gettid();
> 	
> 	for (i=0; i < 10; i++) {
> 		printf("\ni in Thread %d: %d", cur_thr_id, i);
> 	}
> 	
> 	return NULL;
> }
> 
> int main() {
> 	
> 	pthread_t pt[NUM_THREADS];
> 	
> 	int i;	
> 	
>  	// create threads now
> 	for(i=0; i<NUM_THREADS; i++) {
> 		pthread_create(&pt[i], NULL, count, NULL);
> 	}
> 	
> 	// Wait for the threads to exit
> 	for(i=0; i<NUM_THREADS; i++) {
> 		pthread_join(pt[i], NULL);
> 	}
> 	
> 	printf("\nHello World\n");
> 
> 	return 1;
> }
> 
> I am attaching a sample debug session:
> 
> testbed62 [50] % gdb test
> GNU gdb Red Hat Linux (6.0post-0.20040223.19rh)
> Copyright 2004 Free Software Foundation, Inc.
> GDB is free software, covered by the GNU General Public License, and you are
> welcome to change it and/or distribute copies of it under certain conditions.
> Type "show copying" to see the conditions.
> There is absolutely no warranty for GDB.  Type "show warranty" for details.
> This GDB was configured as "i386-redhat-linux-gnu"...Using host libthread_db
library "/lib/tls/libthread_db.so.1".
> 
> (gdb) b main
> Breakpoint 1 at 0x80484d8: file pthread_test.c, line 31.
> (gdb) r
> Starting program: /projects/BERT/spraveen/test_programs/pthread_test/bug/test 
> Error while mapping shared library sections:
> : Success.
> Error while reading shared library symbols:
> : No such file or directory.
> [Thread debugging using libthread_db enabled]
> [New Thread 1073834272 (LWP 26981)]
> Error while reading shared library symbols:
> : No such file or directory.
> Error while reading shared library symbols:
> : No such file or directory.
> [Switching to Thread 1073834272 (LWP 26981)]
> 
> Breakpoint 1, main () at pthread_test.c:31
> 31              for(i=0; i<NUM_THREADS; i++) {
> (gdb) b pthread_test.c:36
> Breakpoint 2 at 0x804850c: file pthread_test.c, line 36.
> (gdb) c
> Continuing.
> [New Thread 1082227632 (LWP 27038)]
> 
> [New Thread 1090620336 (LWP 27039)]
> i in Thread 27038: 0
> [New Thread 1099017136 (LWP 27040)]
> i in Thread 27038: 1
> [New Thread 1107409840 (LWP 27041)]
> 
> Breakpoint 2, main () at pthread_test.c:36
> 36              for(i=0; i<NUM_THREADS; i++) {
> (gdb) info threads
>   5 Thread 1107409840 (LWP 27041)  0x007b815c in clone () from /lib/tls/libc.so.6
>   4 Thread 1099017136 (LWP 27040)  0xffffe410 in ?? ()
>   3 Thread 1090620336 (LWP 27039)  0xffffe410 in ?? ()
>   2 Thread 1082227632 (LWP 27038)  0xffffe410 in ?? ()
> * 1 Thread 1073834272 (LWP 26981)  main () at pthread_test.c:36
> (gdb) b *0x007b815c thread 4
> A parse error in expression, near `thread 4'.
> (gdb) q
> The program is running.  Exit anyway? (y or n) y
> 
> Please send me an email if you need more information about this problem.
> 
> Thanks for very much for your attention and patience.
> 
> Regards,
> Praveen
> 
> Release:
> GNU gdb Red Hat Linux (6.0post-0.20040223.19rh)
> 
> Environment:
> "uname -a" OUTPUT:
> Linux system 2.6.8-1.521 #4 Thu Feb 17 23:33:04 CST 2005 i686 i686 i386 GNU/Linux
> 
> "gcc --version" Output:
> gcc (GCC) 3.3.3 20040412 (Red Hat Linux 3.3.3-7)
> Copyright (C) 2003 Free Software Foundation, Inc.
> This is free software; see the source for copying conditions.  There is NO
> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
> 
> "gdb" output:
> testbed62 [8] % gdb
> GNU gdb Red Hat Linux (6.0post-0.20040223.19rh)
> Copyright 2004 Free Software Foundation, Inc.
> GDB is free software, covered by the GNU General Public License, and you are
> welcome to change it and/or distribute copies of it under certain conditions.
> Type "show copying" to see the conditions.
> There is absolutely no warranty for GDB.  Type "show warranty" for details.
> This GDB was configured as "i386-redhat-linux-gnu".
> 
> "rpm -q glibc" Output:
> glibc-2.3.3-27
> 
> "getconf GNU_LIBPTHREAD_VERSION" Output:
> NPTL 0.61
> 
> How-To-Repeat:
> This problem occurs whenever you try to set a thread specific breakpoint in
the following format.
> 
> break *0x<address> thread <threadno>
> 
> Please see the description for a sample program and a debug session



-- 


http://sourceware.org/bugzilla/show_bug.cgi?id=8980

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