Re: Bad checkin breaks Linux

[Michael Snyder <msnyder@redhat.com>]

"H . J . Lu" wrote:
> 
> This patch
> 
> http://sources.redhat.com/ml/gdb-patches/2002-01/msg00195.html
> 
> breaks Linux targets which don't use PTRACE_GETFPXREGS. The problem is
> <sys/ptrace.h> has
> 
>   /* Single step the process.
>      This is not supported on all machines.  */
>   PTRACE_SINGLESTEP = 9,
> #define PT_STEP PTRACE_SINGLESTEP
> 
>   /* Get all general purpose registers used by a processes.
>      This is not supported on all machines.  */
>    PTRACE_GETREGS = 12,
> #define PT_GETREGS PTRACE_GETREGS
> 
>   /* Set all general purpose registers used by a processes.
>      This is not supported on all machines.  */
>    PTRACE_SETREGS = 13,
> #define PT_SETREGS PTRACE_SETREGS
> 
>   /* Get all floating point registers used by a processes.
>      This is not supported on all machines.  */
>    PTRACE_GETFPREGS = 14,
> #define PT_GETFPREGS PTRACE_GETFPREGS
> 
>   /* Set all floating point registers used by a processes.
>      This is not supported on all machines.  */
>    PTRACE_SETFPREGS = 15,
> #define PT_SETFPREGS PTRACE_SETFPREGS
> 
>   /* Get all extended floating point registers used by a processes.
>      This is not supported on all machines.  */
>    PTRACE_GETFPXREGS = 18,
> #define PT_GETFPXREGS PTRACE_GETFPXREGS
> 
>   /* Set all extended floating point registers used by a processes.
>      This is not supported on all machines.  */
>    PTRACE_SETFPXREGS = 19,
> #define PT_SETFPXREGS PTRACE_SETFPXREGS
> 
> You can't assume you can use PTRACE_GETFPXREGS if it is defined. Due
> to that change, gdb won't build on Linux/mips. 

Well, that's kind of bogus!  ;-(  
Seems to me that HAVE_PTRACE_GETFPXREGS should mean that 
we have ptrace_getfpxregs.  Maybe MIPS should not define
it if it doesn't use it.

OK, I don't see how to resolve this easily -- I'll just
remove the fpxregs from the gcore file for now (so that
it will build for mips).


> I am afraid the current
> gdb from CVS may be broken even without that patch:
> 
> # gcc -c -g -O2    -I. -I/home/hjl/work/gnu/src/gdb/gdb/gdb -I/home/hjl/work/gnu/src/gdb/gdb/gdb/config -DHAVE_CONFIG_H -I/home/hjl/work/gnu/src/gdb/gdb/gdb/../include/opcode -I/home/hjl/work/gnu/src/gdb/gdb/gdb/../readline/.. -I../bfd -I/home/hjl/work/gnu/src/gdb/gdb/gdb/../bfd -I/home/hjl/work/gnu/src/gdb/gdb/gdb/../include -I../intl -I/home/hjl/work/gnu/src/gdb/gdb/gdb/../intl  -DMI_OUT=1 -DUI_OUT=1 -Wimplicit -Wreturn-type -Wcomment -Wtrigraphs -Wformat -Wparentheses -Wpointer-arith -Wuninitialized  /home/hjl/work/gnu/src/gdb/gdb/gdb/thread-db.c
> /home/hjl/work/gnu/src/gdb/gdb/gdb/thread-db.c: In function
> `enable_thread_event_reporting':
> /home/hjl/work/gnu/src/gdb/gdb/gdb/thread-db.c:398: warning: cast from pointer to integer of different size
> /home/hjl/work/gnu/src/gdb/gdb/gdb/thread-db.c:411: warning: cast from pointer to integer of different size
> /home/hjl/work/gnu/src/gdb/gdb/gdb/thread-db.c: In function `thread_db_store_registers':
> /home/hjl/work/gnu/src/gdb/gdb/gdb/thread-db.c:843: warning: passing arg 2 of pointer to function from incompatible pointer type


Check the comment in gdb_proc_service.h (search for "Fix-up some broken
systems"), and see if you may need to define PRFPREGSET_T_BROKEN.

Michael