Re: [PATCH] Implement SDT (SystemTap probes) support for IA-64

[Joel Brobecker <brobecker at adacore dot com>]

Hi Sergio,

> The problem was that IA-64 did not have an implementation for the SDT
> (SystemTap) probes, which was causing a warning to be printed because
> GDB was unable to parse the probe's arguments.  The patch is almost
> trivial; it implements the support on ia64-linux-tdep.c file.
> 
> Regtested on RHEL 5.9 Server IA-64, no regressions.
> 
> Joel, could you please test to see if this works for you?

Many thanks for the patch. I am pretty sure I would have spent hours
figuring it out, and then implementing the necessary bits.

I confirm that this works for me as well.

> 2013-06-26  Sergio Durigan Junior  <sergiodj@redhat.com>
> 
> 	* ia64-linux-tdep.c: Include <ctype.h>.
> 	(ia64_linux_stap_is_single_operand): New function.
> 	(ia64_linux_init_abi): Initialize SystemTap related attributes.

FWIW, this patch looks OK to me.

> 
> diff --git a/gdb/ia64-linux-tdep.c b/gdb/ia64-linux-tdep.c
> index 35ee4e2..2ebe527 100644
> --- a/gdb/ia64-linux-tdep.c
> +++ b/gdb/ia64-linux-tdep.c
> @@ -27,6 +27,8 @@
>  #include "symtab.h"
>  #include "linux-tdep.h"
>  
> +#include <ctype.h>
> +
>  /* The sigtramp code is in a non-readable (executable-only) region
>     of memory called the ``gate page''.  The addresses in question
>     were determined by examining the system headers.  They are
> @@ -118,6 +120,17 @@ ia64_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
>    regcache_cooked_write_unsigned (regcache, IA64_GR10_REGNUM, 0);
>  }
>  
> +/* Implementation of `gdbarch_stap_is_single_operand', as defined in
> +   gdbarch.h.  */
> +
> +static int
> +ia64_linux_stap_is_single_operand (struct gdbarch *gdbarch, const char *s)
> +{
> +  return ((isdigit (*s) && s[1] == '[' && s[2] == 'r') /* Displacement.  */
> +	  || *s == 'r' /* Register value.  */
> +	  || isdigit (*s));  /* Literal number.  */
> +}
> +
>  static void
>  ia64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
>  {
> @@ -142,6 +155,13 @@ ia64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
>    /* Enable TLS support.  */
>    set_gdbarch_fetch_tls_load_module_address (gdbarch,
>                                               svr4_fetch_objfile_link_map);
> +
> +  /* SystemTap related.  */
> +  set_gdbarch_stap_register_prefix (gdbarch, "r");
> +  set_gdbarch_stap_register_indirection_prefix (gdbarch, "[");
> +  set_gdbarch_stap_register_indirection_suffix (gdbarch, "]");
> +  set_gdbarch_stap_gdb_register_prefix (gdbarch, "r");
> +  set_gdbarch_stap_is_single_operand (gdbarch, ia64_linux_stap_is_single_operand);
>  }
>  
>  /* Provide a prototype to silence -Wmissing-prototypes.  */

-- 
Joel