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Re: [patch] Can't build ppc32 GDB
> From: PAUL GILLIAM <pgilliam@us.ibm.com>
> Date: Fri, 05 May 2006 11:32:18 -0700
>
> OK, How about this? I tried to make everyone happy :-)
>
> Here is an excerpt:
>
> #ifdef HAVE_STDINT_H
> #include <stdint.h>
> #define CORE_ADDR_CAST (uintptr_t)
> #else
> #define CORE_ADDR_CAST (CORE_ADDR)(unsigned long)
> #endif
> . . .
> last_stopped_data_address = CORE_ADDR_CAST siginfo.si_addr;
>
> Then when there is a gdb_stdint.h, I'll submit another patch to include
> it and replace CORE_ADDR_CAST with just (uintptr_t).
>
> Ok to commit?
Sorry Paul, this is silly. Just include <stdint.h> and use uintptr_t
unconditionally. Or use unsigned long (the extra CORE_ADDR cast isn't
necessary) if you're really scared that someone will try to compile
GDB on a system with glibc 2.0.x.
Mark
> On Fri, 2006-05-05 at 18:49 +0200, Mark Kettenis wrote:
> > > Date: Fri, 5 May 2006 12:29:55 -0400
> > > From: Daniel Jacobowitz <drow@false.org>
> > >
> > > On Thu, May 04, 2006 at 09:12:14AM +0200, Mark Kettenis wrote:
> > > > This is where the new ISO C99 <stdint.h> types come in handy. Instead of
> > > > casting to CORE_ADDR, try casting to uintptr_t.
> > >
> > > Can we rely on <stdint.h> on GNU/Linux? I know we can't in general.
> > > Conveniently, I have a patch on one of my pending branches that
> > > provides a gdb_stdint.h.
> >
> > Having a gdb_stdint.h would be cool ;-).
> >
> > > But for this case there's an easier solution, which IIRC is roughly
> > > what Paul did: I can pretty much promise you that sizeof (long) ==
> > > sizeof (void *) on any GNU/Linux system. So either I can merge
> > > gdb_stdint.h and we can start using that, which might be a nice idea in
> > > general, or for now I think "long" is fine.
> >
> > Well, we already use uintptr_t in linux-thread-db.c, and
> > gdb_thread_db.h errors out if it isn't available (and has been doing
> > so for ages). So we can be pretty sure that nobody is trying to
> > compile on systems with libc5 or really old glibc versions.
> >
> > That said, it is probably safe to assume that all (powerpc) Linux
> > ports are either ILP32 or LP64, so casting to (unsigned long) should
> > be perfectly safe. It's just that I think that a uintptr_t cast
> > better expresses what's happening here. But either way is fine with
> > me.
> >
> > Mark
>
> --=-+yu21rc4iHrvNYe3G7+v
> Content-Disposition: attachment; filename=ppc-linux-nat.diff
> Content-Type: text/x-patch; name=ppc-linux-nat.diff; charset=utf-8
> Content-Transfer-Encoding: 7bit
>
> 2006-04-26: Paul Gilliam <pgilliam@us.ibm.com>
>
> * ppc-linux-nat.c: Clean up types for ptrace.
> New macro 'CORE_ADDR_CAST' accounts for the size difference between
> a CORE_ADDR and a void* on ppc64 systems compiled for 32-bits.
>
> Index: ppc-linux-nat.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/ppc-linux-nat.c,v
> retrieving revision 1.60
> diff -a -u -r1.60 ppc-linux-nat.c
> --- ppc-linux-nat.c 24 Mar 2006 23:08:16 -0000 1.60
> +++ ppc-linux-nat.c 5 May 2006 18:15:28 -0000
> @@ -30,6 +30,13 @@
> #include "target.h"
> #include "linux-nat.h"
>
> +#ifdef HAVE_STDINT_H
> +#include <stdint.h>
> +#define CORE_ADDR_CAST (uintptr_t)
> +#else
> +#define CORE_ADDR_CAST (CORE_ADDR)(unsigned long)
> +#endif
> +
> #include <sys/types.h>
> #include <sys/param.h>
> #include <signal.h>
> @@ -44,18 +51,6 @@
> #include "gregset.h"
> #include "ppc-tdep.h"
>
> -#ifndef PT_READ_U
> -#define PT_READ_U PTRACE_PEEKUSR
> -#endif
> -#ifndef PT_WRITE_U
> -#define PT_WRITE_U PTRACE_POKEUSR
> -#endif
> -
> -/* Default the type of the ptrace transfer to int. */
> -#ifndef PTRACE_XFER_TYPE
> -#define PTRACE_XFER_TYPE int
> -#endif
> -
> /* Glibc's headers don't define PTRACE_GETVRREGS so we cannot use a
> configure time check. Some older glibc's (for instance 2.2.1)
> don't have a specific powerpc version of ptrace.h, and fall back on
> @@ -126,13 +121,12 @@
>
> /* On PPC processors that support the the Signal Processing Extension
> (SPE) APU, the general-purpose registers are 64 bits long.
> - However, the ordinary Linux kernel PTRACE_PEEKUSR / PTRACE_POKEUSR
> - / PT_READ_U / PT_WRITE_U ptrace calls only access the lower half of
> - each register, to allow them to behave the same way they do on
> - non-SPE systems. There's a separate pair of calls,
> - PTRACE_GETEVRREGS / PTRACE_SETEVRREGS, that read and write the top
> - halves of all the general-purpose registers at once, along with
> - some SPE-specific registers.
> + However, the ordinary Linux kernel PTRACE_PEEKUSER / PTRACE_POKEUSER
> + ptrace calls only access the lower half of each register, to allow
> + them to behave the same way they do on non-SPE systems. There's a
> + separate pair of calls, PTRACE_GETEVRREGS / PTRACE_SETEVRREGS, that
> + read and write the top halves of all the general-purpose registers
> + at once, along with some SPE-specific registers.
>
> GDB itself continues to claim the general-purpose registers are 32
> bits long. It has unnamed raw registers that hold the upper halves
> @@ -190,7 +184,7 @@
> struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
> /* NOTE: cagney/2003-11-25: This is the word size used by the ptrace
> interface, and not the wordsize of the program's ABI. */
> - int wordsize = sizeof (PTRACE_XFER_TYPE);
> + int wordsize = sizeof (long);
>
> /* General purpose registers occupy 1 slot each in the buffer */
> if (regno >= tdep->ppc_gp0_regnum
> @@ -384,17 +378,17 @@
> return;
> }
>
> - /* Read the raw register using PTRACE_XFER_TYPE sized chunks. On a
> + /* Read the raw register using sizeof(long) sized chunks. On a
> 32-bit platform, 64-bit floating-point registers will require two
> transfers. */
> for (bytes_transferred = 0;
> bytes_transferred < register_size (current_gdbarch, regno);
> - bytes_transferred += sizeof (PTRACE_XFER_TYPE))
> + bytes_transferred += sizeof (long))
> {
> errno = 0;
> - *(PTRACE_XFER_TYPE *) & buf[bytes_transferred]
> - = ptrace (PT_READ_U, tid, (PTRACE_ARG3_TYPE) regaddr, 0);
> - regaddr += sizeof (PTRACE_XFER_TYPE);
> + *(long *) & buf[bytes_transferred]
> + = ptrace (PTRACE_PEEKUSER, tid, (PTRACE_TYPE_ARG3) regaddr, 0);
> + regaddr += sizeof (long);
> if (errno != 0)
> {
> char message[128];
> @@ -406,7 +400,7 @@
>
> /* Now supply the register. Keep in mind that the regcache's idea
> of the register's size may not be a multiple of sizeof
> - (PTRACE_XFER_TYPE). */
> + (long). */
> if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_LITTLE)
> {
> /* Little-endian values are always found at the left end of the
> @@ -668,10 +662,10 @@
>
> /* First collect the register. Keep in mind that the regcache's
> idea of the register's size may not be a multiple of sizeof
> - (PTRACE_XFER_TYPE). */
> + (long). */
> memset (buf, 0, sizeof buf);
> bytes_to_transfer = align_up (register_size (current_gdbarch, regno),
> - sizeof (PTRACE_XFER_TYPE));
> + sizeof (long));
> if (TARGET_BYTE_ORDER == BFD_ENDIAN_LITTLE)
> {
> /* Little-endian values always sit at the left end of the buffer. */
> @@ -685,12 +679,12 @@
> regcache_raw_collect (current_regcache, regno, buf + padding);
> }
>
> - for (i = 0; i < bytes_to_transfer; i += sizeof (PTRACE_XFER_TYPE))
> + for (i = 0; i < bytes_to_transfer; i += sizeof (long))
> {
> errno = 0;
> - ptrace (PT_WRITE_U, tid, (PTRACE_ARG3_TYPE) regaddr,
> - *(PTRACE_XFER_TYPE *) & buf[i]);
> - regaddr += sizeof (PTRACE_XFER_TYPE);
> + ptrace (PTRACE_POKEUSER, tid, (PTRACE_TYPE_ARG3) regaddr,
> + *(long *) & buf[i]);
> + regaddr += sizeof (long);
>
> if (errno == EIO
> && regno == tdep->ppc_fpscr_regnum)
> @@ -901,7 +895,7 @@
> (siginfo.si_code & 0xffff) != 0x0004)
> return 0;
>
> - last_stopped_data_address = (CORE_ADDR) siginfo.si_addr;
> + last_stopped_data_address = CORE_ADDR_CAST siginfo.si_addr;
> return 1;
> }
>
> @@ -926,7 +920,7 @@
> {
> /* NOTE: cagney/2003-11-25: This is the word size used by the ptrace
> interface, and not the wordsize of the program's ABI. */
> - int wordsize = sizeof (PTRACE_XFER_TYPE);
> + int wordsize = sizeof (long);
> ppc_linux_supply_gregset (current_regcache, -1, gregsetp,
> sizeof (gdb_gregset_t), wordsize);
> }
> @@ -936,7 +930,7 @@
> {
> /* NOTE: cagney/2003-11-25: This is the word size used by the ptrace
> interface, and not the wordsize of the program's ABI. */
> - int wordsize = sizeof (PTRACE_XFER_TYPE);
> + int wordsize = sizeof (long);
> /* Right fill the register. */
> regcache_raw_collect (current_regcache, regnum,
> ((bfd_byte *) reg
>
> --=-+yu21rc4iHrvNYe3G7+v--
>
>