[patch/rfc] Eliminate TARGET_BYTE_ORDER_SELECTABLE

[patch/rfc] Eliminate TARGET_BYTE_ORDER_SELECTABLE

[Andrew Cagney]

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Hello,

All multi-arch targets (yep, including the i386) allow the byte order to 
be selected at run time.  This means that the macro 
TARGET_BYTE_ORDER_SELECTABLE which was used by non-multi-arch targets is 
obsolete.

The attached patch eliminates that macro.  I've tested it on a 
multi-arch target and I don't think it breaks non-multi-arch targets.

Anyway, I intend committing this in a few days.
Andrew

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2002-01-19  Andrew Cagney  <ac131313@redhat.com>

	* remote-sim.c (gdbsim_open): Simplify code testing the macro
	TARGET_BYTE_ORDER_SELECTABLE_P.  Assume the target is always
	byte-order selectable.
	* sparc-tdep.c (sparc_target_architecture_hook): Ditto.
	* arch-utils.c: Ditto.
	(set_endian): Ditto.
	(set_endian_from_file): Ditto.
	* gdbserver/low-sim.c (create_inferior): Ditto.
	* gdbarch.sh: Ditto.
	* gdbarch.h: Re-generate.
	* config/powerpc/tm-ppc-eabi.h (TARGET_BYTE_ORDER_SELECTABLE_P): 
	* config/sparc/tm-sparclite.h (TARGET_BYTE_ORDER_SELECTABLE): 
	* config/sparc/tm-sparclet.h (TARGET_BYTE_ORDER_SELECTABLE): 
	* config/mcore/tm-mcore.h (TARGET_BYTE_ORDER_SELECTABLE_P): 
	* config/arm/tm-wince.h (TARGET_BYTE_ORDER_SELECTABLE_P): 
	* config/arm/tm-linux.h (TARGET_BYTE_ORDER_SELECTABLE_P): 
	* config/arc/tm-arc.h (TARGET_BYTE_ORDER_SELECTABLE): 
	* config/arm/tm-arm.h (TARGET_BYTE_ORDER_SELECTABLE_P): Delete
	macro definition.
	* config/mips/tm-wince.h: Remove #undef of macro
	TARGET_BYTE_ORDER_SELECTABLE.
	* config/sh/tm-wince.h: Ditto.

Index: arch-utils.c
===================================================================
RCS file: /cvs/src/src/gdb/arch-utils.c,v
retrieving revision 1.46
diff -p -r1.46 arch-utils.c
*** arch-utils.c	2002/01/05 04:30:14	1.46
--- arch-utils.c	2002/01/19 05:51:15
*************** generic_register_virtual_size (int regnu
*** 399,422 ****
  \f
  /* Functions to manipulate the endianness of the target.  */
  
- #ifdef TARGET_BYTE_ORDER_SELECTABLE
- /* compat - Catch old targets that expect a selectable byte-order to
-    default to BFD_ENDIAN_BIG */
  #ifndef TARGET_BYTE_ORDER_DEFAULT
- #define TARGET_BYTE_ORDER_DEFAULT BFD_ENDIAN_BIG
- #endif
- #endif
- #if !TARGET_BYTE_ORDER_SELECTABLE_P
- #ifndef TARGET_BYTE_ORDER_DEFAULT
- /* compat - Catch old non byte-order selectable targets that do not
-    define TARGET_BYTE_ORDER_DEFAULT and instead expect
-    TARGET_BYTE_ORDER to be used as the default.  For targets that
-    defined neither TARGET_BYTE_ORDER nor TARGET_BYTE_ORDER_DEFAULT the
-    below will get a strange compiler warning. */
- #define TARGET_BYTE_ORDER_DEFAULT TARGET_BYTE_ORDER
- #endif
- #endif
- #ifndef TARGET_BYTE_ORDER_DEFAULT
  #define TARGET_BYTE_ORDER_DEFAULT BFD_ENDIAN_BIG /* arbitrary */
  #endif
  /* ``target_byte_order'' is only used when non- multi-arch.
--- 399,405 ----
*************** show_endian (char *args, int from_tty)
*** 453,463 ****
  static void
  set_endian (char *ignore_args, int from_tty, struct cmd_list_element *c)
  {
!   if (!TARGET_BYTE_ORDER_SELECTABLE_P)
!     {
!       printf_unfiltered ("Byte order is not selectable.");
!     }
!   else if (set_endian_string == endian_auto)
      {
        target_byte_order_auto = 1;
      }
--- 436,442 ----
  static void
  set_endian (char *ignore_args, int from_tty, struct cmd_list_element *c)
  {
!   if (set_endian_string == endian_auto)
      {
        target_byte_order_auto = 1;
      }
*************** set_endian (char *ignore_args, int from_
*** 508,540 ****
  static void
  set_endian_from_file (bfd *abfd)
  {
    if (GDB_MULTI_ARCH)
      internal_error (__FILE__, __LINE__,
  		    "set_endian_from_file: not for multi-arch");
!   if (TARGET_BYTE_ORDER_SELECTABLE_P)
!     {
!       int want;
!       
!       if (bfd_big_endian (abfd))
! 	want = BFD_ENDIAN_BIG;
!       else
! 	want = BFD_ENDIAN_LITTLE;
!       if (TARGET_BYTE_ORDER_AUTO)
! 	target_byte_order = want;
!       else if (TARGET_BYTE_ORDER != want)
! 	warning ("%s endian file does not match %s endian target.",
! 		 want == BFD_ENDIAN_BIG ? "big" : "little",
! 		 TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little");
!     }
    else
!     {
!       if (bfd_big_endian (abfd)
! 	  ? TARGET_BYTE_ORDER != BFD_ENDIAN_BIG
! 	  : TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
! 	warning ("%s endian file does not match %s endian target.",
! 		 bfd_big_endian (abfd) ? "big" : "little",
! 		 TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little");
!     }
  }
  
  
--- 487,506 ----
  static void
  set_endian_from_file (bfd *abfd)
  {
+   int want;
    if (GDB_MULTI_ARCH)
      internal_error (__FILE__, __LINE__,
  		    "set_endian_from_file: not for multi-arch");
!   if (bfd_big_endian (abfd))
!     want = BFD_ENDIAN_BIG;
    else
!     want = BFD_ENDIAN_LITTLE;
!   if (TARGET_BYTE_ORDER_AUTO)
!     target_byte_order = want;
!   else if (TARGET_BYTE_ORDER != want)
!     warning ("%s endian file does not match %s endian target.",
! 	     want == BFD_ENDIAN_BIG ? "big" : "little",
! 	     TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little");
  }
  
  
Index: gdbarch.h
===================================================================
RCS file: /cvs/src/src/gdb/gdbarch.h,v
retrieving revision 1.73
diff -p -r1.73 gdbarch.h
*** gdbarch.h	2001/12/29 19:25:58	1.73
--- gdbarch.h	2002/01/19 05:51:22
*************** extern void register_gdbarch_swap (void 
*** 2408,2440 ****
  
  /* The target-system-dependent byte order is dynamic */
  
- /* TARGET_BYTE_ORDER_SELECTABLE_P determines if the target endianness
-    is selectable at runtime.  The user can use the ``set endian''
-    command to change it.  TARGET_BYTE_ORDER_AUTO is nonzero when
-    target_byte_order should be auto-detected (from the program image
-    say). */
- 
- #if GDB_MULTI_ARCH
- /* Multi-arch GDB is always bi-endian. */
- #define TARGET_BYTE_ORDER_SELECTABLE_P 1
- #endif
- 
- #ifndef TARGET_BYTE_ORDER_SELECTABLE_P
- /* compat - Catch old targets that define TARGET_BYTE_ORDER_SLECTABLE
-    when they should have defined TARGET_BYTE_ORDER_SELECTABLE_P 1 */
- #ifdef TARGET_BYTE_ORDER_SELECTABLE
- #define TARGET_BYTE_ORDER_SELECTABLE_P 1
- #else
- #define TARGET_BYTE_ORDER_SELECTABLE_P 0
- #endif
- #endif
- 
  extern int target_byte_order;
- #ifdef TARGET_BYTE_ORDER_SELECTABLE
- /* compat - Catch old targets that define TARGET_BYTE_ORDER_SELECTABLE
-    and expect defs.h to re-define TARGET_BYTE_ORDER. */
- #undef TARGET_BYTE_ORDER
- #endif
  #ifndef TARGET_BYTE_ORDER
  #define TARGET_BYTE_ORDER (target_byte_order + 0)
  #endif
--- 2408,2414 ----
Index: gdbarch.sh
===================================================================
RCS file: /cvs/src/src/gdb/gdbarch.sh,v
retrieving revision 1.103
diff -p -r1.103 gdbarch.sh
*** gdbarch.sh	2002/01/05 04:30:17	1.103
--- gdbarch.sh	2002/01/19 05:51:24
*************** extern void register_gdbarch_swap (void 
*** 1058,1090 ****
  
  /* The target-system-dependent byte order is dynamic */
  
- /* TARGET_BYTE_ORDER_SELECTABLE_P determines if the target endianness
-    is selectable at runtime.  The user can use the \`\`set endian''
-    command to change it.  TARGET_BYTE_ORDER_AUTO is nonzero when
-    target_byte_order should be auto-detected (from the program image
-    say). */
- 
- #if GDB_MULTI_ARCH
- /* Multi-arch GDB is always bi-endian. */
- #define TARGET_BYTE_ORDER_SELECTABLE_P 1
- #endif
- 
- #ifndef TARGET_BYTE_ORDER_SELECTABLE_P
- /* compat - Catch old targets that define TARGET_BYTE_ORDER_SLECTABLE
-    when they should have defined TARGET_BYTE_ORDER_SELECTABLE_P 1 */
- #ifdef TARGET_BYTE_ORDER_SELECTABLE
- #define TARGET_BYTE_ORDER_SELECTABLE_P 1
- #else
- #define TARGET_BYTE_ORDER_SELECTABLE_P 0
- #endif
- #endif
- 
  extern int target_byte_order;
- #ifdef TARGET_BYTE_ORDER_SELECTABLE
- /* compat - Catch old targets that define TARGET_BYTE_ORDER_SELECTABLE
-    and expect defs.h to re-define TARGET_BYTE_ORDER. */
- #undef TARGET_BYTE_ORDER
- #endif
  #ifndef TARGET_BYTE_ORDER
  #define TARGET_BYTE_ORDER (target_byte_order + 0)
  #endif
--- 1058,1064 ----
Index: remote-sim.c
===================================================================
RCS file: /cvs/src/src/gdb/remote-sim.c,v
retrieving revision 1.19
diff -p -r1.19 remote-sim.c
*** remote-sim.c	2002/01/05 04:30:18	1.19
--- remote-sim.c	2002/01/19 05:51:27
*************** gdbsim_open (char *args, int from_tty)
*** 472,479 ****
    strcpy (arg_buf, "gdbsim");	/* 7 */
    /* Specify the byte order for the target when it is both selectable
       and explicitly specified by the user (not auto detected). */
!   if (TARGET_BYTE_ORDER_SELECTABLE_P
!       && !TARGET_BYTE_ORDER_AUTO)
      {
        switch (TARGET_BYTE_ORDER)
  	{
--- 472,478 ----
    strcpy (arg_buf, "gdbsim");	/* 7 */
    /* Specify the byte order for the target when it is both selectable
       and explicitly specified by the user (not auto detected). */
!   if (!TARGET_BYTE_ORDER_AUTO)
      {
        switch (TARGET_BYTE_ORDER)
  	{
Index: sparc-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/sparc-tdep.c,v
retrieving revision 1.20
diff -p -r1.20 sparc-tdep.c
*** sparc-tdep.c	2001/12/30 17:00:43	1.20
--- sparc-tdep.c	2002/01/19 05:51:33
*************** sparc_target_architecture_hook (const bf
*** 2200,2214 ****
  
    if (ap->mach == bfd_mach_sparc_sparclite_le)
      {
!       if (TARGET_BYTE_ORDER_SELECTABLE_P)
! 	{
! 	  target_byte_order = BFD_ENDIAN_LITTLE;
! 	  bi_endian = 1;
! 	}
!       else
! 	{
! 	  warning ("This GDB does not support little endian sparclite.");
! 	}
      }
    else
      bi_endian = 0;
--- 2200,2207 ----
  
    if (ap->mach == bfd_mach_sparc_sparclite_le)
      {
!       target_byte_order = BFD_ENDIAN_LITTLE;
!       bi_endian = 1;
      }
    else
      bi_endian = 0;
Index: config/arc/tm-arc.h
===================================================================
RCS file: /cvs/src/src/gdb/config/arc/tm-arc.h,v
retrieving revision 1.7
diff -p -r1.7 tm-arc.h
*** tm-arc.h	2001/03/21 18:31:48	1.7
--- tm-arc.h	2002/01/19 05:51:36
***************
*** 24,32 ****
  /* Used by arc-tdep.c to set the default cpu type.  */
  #define DEFAULT_ARC_CPU_TYPE "base"
  
- /* Byte order is selectable.  */
- #define	TARGET_BYTE_ORDER_SELECTABLE
- 
  /* We have IEEE floating point, if we have any float at all.  */
  #define IEEE_FLOAT (1)
  
--- 24,29 ----
Index: config/arm/tm-arm.h
===================================================================
RCS file: /cvs/src/src/gdb/config/arm/tm-arm.h,v
retrieving revision 1.13
diff -p -r1.13 tm-arm.h
*** tm-arm.h	2002/01/09 18:39:37	1.13
--- tm-arm.h	2002/01/19 05:51:37
*************** struct value;
*** 31,37 ****
  
  /* Target byte order on ARM defaults to selectable, and defaults to
     little endian.  */
- #define TARGET_BYTE_ORDER_SELECTABLE_P	1
  #define TARGET_BYTE_ORDER_DEFAULT BFD_ENDIAN_LITTLE
  
  /* IEEE format floating point.  */
--- 31,36 ----
Index: config/arm/tm-linux.h
===================================================================
RCS file: /cvs/src/src/gdb/config/arm/tm-linux.h,v
retrieving revision 1.8
diff -p -r1.8 tm-linux.h
*** tm-linux.h	2001/12/05 15:11:48	1.8
--- tm-linux.h	2002/01/19 05:51:37
***************
*** 34,43 ****
  extern struct link_map_offsets *arm_linux_svr4_fetch_link_map_offsets (void);
  #define SVR4_FETCH_LINK_MAP_OFFSETS() arm_linux_svr4_fetch_link_map_offsets ()
  
- /* Target byte order on ARM Linux is little endian and not selectable.  */
- #undef TARGET_BYTE_ORDER_SELECTABLE_P
- #define TARGET_BYTE_ORDER_SELECTABLE_P	0
- 
  /* Under ARM Linux the traditional way of performing a breakpoint is to
     execute a particular software interrupt, rather than use a particular
     undefined instruction to provoke a trap.  Upon exection of the software
--- 34,39 ----
Index: config/arm/tm-wince.h
===================================================================
RCS file: /cvs/src/src/gdb/config/arm/tm-wince.h,v
retrieving revision 1.3
diff -p -r1.3 tm-wince.h
*** tm-wince.h	2001/03/20 18:16:16	1.3
--- tm-wince.h	2002/01/19 05:51:37
***************
*** 31,38 ****
  
  void wince_software_single_step (unsigned int, int);
  
- /* Target byte order is little endian and not selectable on WinCE. */
- #undef  TARGET_BYTE_ORDER_SELECTABLE_P
- #define TARGET_BYTE_ORDER_SELECTABLE_P	0
- 
  #endif /* TM_WINCE_H */
--- 31,34 ----
Index: config/mcore/tm-mcore.h
===================================================================
RCS file: /cvs/src/src/gdb/config/mcore/tm-mcore.h,v
retrieving revision 1.7
diff -p -r1.7 tm-mcore.h
*** tm-mcore.h	2001/12/15 16:53:23	1.7
--- tm-mcore.h	2002/01/19 05:51:37
*************** extern void mcore_virtual_frame_pointer 
*** 155,163 ****
  #define TARGET_VIRTUAL_FRAME_POINTER(PC, REGP, OFFP) \
  	mcore_virtual_frame_pointer ((PC), (REGP), (OFFP))
  
- /* MCore can be bi-endian. */
- #define TARGET_BYTE_ORDER_SELECTABLE_P 1
- 
  /* For PE, gcc will tell us what th real type of
     arguments are when it promotes arguments. */
  #define BELIEVE_PCC_PROMOTION 1
--- 155,160 ----
Index: config/mips/tm-wince.h
===================================================================
RCS file: /cvs/src/src/gdb/config/mips/tm-wince.h,v
retrieving revision 1.4
diff -p -r1.4 tm-wince.h
*** tm-wince.h	2001/12/15 16:53:23	1.4
--- tm-wince.h	2002/01/19 05:51:37
***************
*** 29,35 ****
  #define SOFTWARE_SINGLE_STEP(sig, bp_p) wince_software_single_step (sig, bp_p)
  
  void wince_software_single_step (unsigned int, int);
- #undef TARGET_BYTE_ORDER_SELECTABLE
  #define TARGET_BYTE_ORDER BFD_ENDIAN_LITTLE
  
  #endif /* TM_WINCE_H */
--- 29,34 ----
Index: config/powerpc/tm-ppc-eabi.h
===================================================================
RCS file: /cvs/src/src/gdb/config/powerpc/tm-ppc-eabi.h,v
retrieving revision 1.7
diff -p -r1.7 tm-ppc-eabi.h
*** tm-ppc-eabi.h	2001/12/03 21:17:49	1.7
--- tm-ppc-eabi.h	2002/01/19 05:51:37
***************
*** 39,46 ****
  /* Say that we're using ELF, not XCOFF.  */
  #define ELF_OBJECT_FORMAT 1
  
- #define TARGET_BYTE_ORDER_SELECTABLE_P 1
- 
  /* The value of symbols of type N_SO and N_FUN maybe null when 
     it shouldn't be. */
  #define SOFUN_ADDRESS_MAYBE_MISSING
--- 39,44 ----
Index: config/sh/tm-wince.h
===================================================================
RCS file: /cvs/src/src/gdb/config/sh/tm-wince.h,v
retrieving revision 1.5
diff -p -r1.5 tm-wince.h
*** tm-wince.h	2001/12/15 16:53:24	1.5
--- tm-wince.h	2002/01/19 05:51:37
***************
*** 28,34 ****
  #undef SOFTWARE_SINGLE_STEP
  #define SOFTWARE_SINGLE_STEP(sig, bp_p) wince_software_single_step (sig, bp_p)
  void wince_software_single_step (unsigned int, int);
- #undef TARGET_BYTE_ORDER_SELECTABLE
  #define TARGET_BYTE_ORDER BFD_ENDIAN_LITTLE
  
  #endif /* TM_WINCE_H */
--- 28,33 ----
Index: config/sparc/tm-sparclet.h
===================================================================
RCS file: /cvs/src/src/gdb/config/sparc/tm-sparclet.h,v
retrieving revision 1.5
diff -p -r1.5 tm-sparclet.h
*** tm-sparclet.h	2001/03/14 23:23:14	1.5
--- tm-sparclet.h	2002/01/19 05:51:37
*************** enum { 
*** 49,55 ****
  /* overrides of tm-sparc.h */
  
  #undef TARGET_BYTE_ORDER
- #define TARGET_BYTE_ORDER_SELECTABLE
  
  /* Sequence of bytes for breakpoint instruction (ta 1). */
  #undef BREAKPOINT
--- 49,54 ----
Index: config/sparc/tm-sparclite.h
===================================================================
RCS file: /cvs/src/src/gdb/config/sparc/tm-sparclite.h,v
retrieving revision 1.4
diff -p -r1.4 tm-sparclite.h
*** tm-sparclite.h	2001/03/14 23:23:14	1.4
--- tm-sparclite.h	2002/01/19 05:51:39
*************** enum {
*** 45,51 ****
  /* overrides of tm-sparc.h */
  
  #undef TARGET_BYTE_ORDER
- #define TARGET_BYTE_ORDER_SELECTABLE
  
  /* Select the sparclite disassembler.  Slightly different instruction set from
     the V8 sparc.  */
--- 45,50 ----
Index: doc/ChangeLog
===================================================================
RCS file: /cvs/src/src/gdb/doc/ChangeLog,v
retrieving revision 1.136
diff -p -r1.136 ChangeLog
*** ChangeLog	2002/01/18 04:51:09	1.136
--- ChangeLog	2002/01/19 05:51:45
***************
*** 1,3 ****
--- 1,8 ----
+ 2002-01-19  Andrew Cagney  <ac131313@redhat.com>
+ 
+ 	* gdbint.texinfo (Target Architecture Definition): Delete
+ 	description of TARGET_BYTE_ORDER_SELECTABLE_P.
+ 
  2002-01-17  Andrew Cagney  <ac131313@redhat.com>
  
  	* gdbint.texinfo (Host Definition): Remove references to XDEPFILES
Index: doc/gdbint.texinfo
===================================================================
RCS file: /cvs/src/src/gdb/doc/gdbint.texinfo,v
retrieving revision 1.56
diff -p -r1.56 gdbint.texinfo
*** gdbint.texinfo	2002/01/18 04:51:10	1.56
--- gdbint.texinfo	2002/01/19 05:51:53
*************** The ordering of bytes in the target.  Th
*** 3482,3493 ****
  @code{BFD_ENDIAN_BIG} or @code{BFD_ENDIAN_LITTLE}.  This macro replaces
  @code{TARGET_BYTE_ORDER} which is deprecated.
  
- @item TARGET_BYTE_ORDER_SELECTABLE_P
- @findex TARGET_BYTE_ORDER_SELECTABLE_P
- Non-zero if the target has both @code{BIG_ENDIAN} and
- @code{BFD_ENDIAN_LITTLE} variants.  This macro replaces
- @code{TARGET_BYTE_ORDER_SELECTABLE} which is deprecated.
- 
  @item TARGET_CHAR_BIT
  @findex TARGET_CHAR_BIT
  Number of bits in a char; defaults to 8.
--- 3482,3487 ----
Index: gdbserver/low-sim.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/low-sim.c,v
retrieving revision 1.6
diff -p -r1.6 low-sim.c
*** low-sim.c	2002/01/17 21:13:49	1.6
--- low-sim.c	2002/01/19 05:51:53
*************** create_inferior (char *program, char **a
*** 88,97 ****
  {
    bfd *abfd;
    int pid = 0;
- #ifdef TARGET_BYTE_ORDER_SELECTABLE
    char **new_argv;
    int nargs;
- #endif
  
    abfd = bfd_openr (program, 0);
    if (!abfd)
--- 88,95 ----
*************** create_inferior (char *program, char **a
*** 108,114 ****
        exit (1);
      }
  
- #ifdef TARGET_BYTE_ORDER_SELECTABLE
    /* Add "-E big" or "-E little" to the argument list depending on the
       endianness of the program to be loaded.  */
    for (nargs = 0; argv[nargs] != NULL; nargs++)		/* count the args */
--- 106,111 ----
*************** create_inferior (char *program, char **a
*** 120,126 ****
    new_argv[nargs + 1] = bfd_big_endian (abfd) ? "big" : "little";
    new_argv[nargs + 2] = NULL;
    argv = new_argv;
- #endif
  
    /* Create an instance of the simulator.  */
    default_callback.init (&default_callback);
--- 117,122 ----

Re: [patch/rfc] Eliminate TARGET_BYTE_ORDER_SELECTABLE

[Daniel Jacobowitz]

On Sat, Jan 19, 2002 at 12:58:36AM -0500, Andrew Cagney wrote:
> Hello,
> 
> All multi-arch targets (yep, including the i386) allow the byte order to 
> be selected at run time.  This means that the macro 
> TARGET_BYTE_ORDER_SELECTABLE which was used by non-multi-arch targets is 
> obsolete.
> 
> The attached patch eliminates that macro.  I've tested it on a 
> multi-arch target and I don't think it breaks non-multi-arch targets.
> 
> Anyway, I intend committing this in a few days.
> Andrew

Hmm, I don't know.  Do we really want to do this?  This allows, for
instance, 'set endian big' on i386.  That may someday make someone
think that GDB supports such a beast, on the off chance one is ever
made.


-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer

Re: [patch/rfc] Eliminate TARGET_BYTE_ORDER_SELECTABLE

[Michael Snyder]

Daniel Jacobowitz wrote:
> 
> On Sat, Jan 19, 2002 at 12:58:36AM -0500, Andrew Cagney wrote:
> > Hello,
> >
> > All multi-arch targets (yep, including the i386) allow the byte order to
> > be selected at run time.  This means that the macro
> > TARGET_BYTE_ORDER_SELECTABLE which was used by non-multi-arch targets is
> > obsolete.
> >
> > The attached patch eliminates that macro.  I've tested it on a
> > multi-arch target and I don't think it breaks non-multi-arch targets.
> >
> > Anyway, I intend committing this in a few days.
> > Andrew
> 
> Hmm, I don't know.  Do we really want to do this?  This allows, for
> instance, 'set endian big' on i386.  That may someday make someone
> think that GDB supports such a beast, on the off chance one is ever
> made.

There's a fairly good chance that gdb WOULD support such a
beast (on the off chance that one is ever made).  If we've
done our jobs and used "extract_unsigned_integer" etc. 
instead of reading things directly from memory...

Re: [patch/rfc] Eliminate TARGET_BYTE_ORDER_SELECTABLE

[Andrew Cagney]

> On Sat, Jan 19, 2002 at 12:58:36AM -0500, Andrew Cagney wrote:
> 
>> Hello,
>> 
>> All multi-arch targets (yep, including the i386) allow the byte order to 
>> be selected at run time.  This means that the macro 
>> TARGET_BYTE_ORDER_SELECTABLE which was used by non-multi-arch targets is 
>> obsolete.
>> 
>> The attached patch eliminates that macro.  I've tested it on a 
>> multi-arch target and I don't think it breaks non-multi-arch targets.
>> 
>> Anyway, I intend committing this in a few days.
>> Andrew
> 
> 
> Hmm, I don't know.  Do we really want to do this?  This allows, for
> instance, 'set endian big' on i386.  That may someday make someone
> think that GDB supports such a beast, on the off chance one is ever
> made.


Ah, but we live in dangerous times :-)

TARGET_BYTE_ORDER_SELECTABLE, TARGET_BYTE_ORDER_SELECTABLE_P and even 
TARGET_BYTE_ORDER_DEFAULT are all there just to prop up old pre- 
multi-arch targets.  They are not used by a multi-arch GDB.

All multi-arch architectures allow both big and little byte orders 
(regardless of what the spec says).  This lets the user do things like:

	(gdb) print network_structure
	(gdb) set endian big
	(gdb) print network_structure

enjoy,
Andrew

Re: [patch/rfc] Eliminate TARGET_BYTE_ORDER_SELECTABLE

[Daniel Jacobowitz]

On Sat, Jan 19, 2002 at 11:57:10AM -0500, Andrew Cagney wrote:
> 
> 
> Ah, but we live in dangerous times :-)
> 
> TARGET_BYTE_ORDER_SELECTABLE, TARGET_BYTE_ORDER_SELECTABLE_P and even 
> TARGET_BYTE_ORDER_DEFAULT are all there just to prop up old pre- 
> multi-arch targets.  They are not used by a multi-arch GDB.
> 
> All multi-arch architectures allow both big and little byte orders 
> (regardless of what the spec says).  This lets the user do things like:
> 
> 	(gdb) print network_structure
> 	(gdb) set endian big
> 	(gdb) print network_structure

Woah!  That's neat!  I need to remember that :)

And I suppose I of all people shouldn't be griping about allowing more
endianness choices.  I have a patch here to support big-endian
ARM/Linux.  All I did was change TARGET_BYTE_ORDER_*.

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer

Re: [patch/rfc] Eliminate TARGET_BYTE_ORDER_SELECTABLE

[Eli Zaretskii]

On Sat, 19 Jan 2002, Andrew Cagney wrote:

> + 2002-01-19  Andrew Cagney  <ac131313@redhat.com>
> + 
> + 	* gdbint.texinfo (Target Architecture Definition): Delete
> + 	description of TARGET_BYTE_ORDER_SELECTABLE_P.

This part of the patch is approved.

Re: [patch/rfc] Eliminate TARGET_BYTE_ORDER_SELECTABLE

[Andrew Cagney]

> 
> Woah!  That's neat!  I need to remember that :)
> 
> And I suppose I of all people shouldn't be griping about allowing more
> endianness choices.  I have a patch here to support big-endian
> ARM/Linux.  All I did was change TARGET_BYTE_ORDER_*.


Delete it :-)  As Michael observed, if the code is written correctly it 
works from day one.  (Problem is it has taken ~10 years to figure out 
how to correctly write the code :-)

Oh, if you think that is neat, just wait until someone adds byte-order 
information to ``struct type''.  As it is, gdb knows about the byte 
order of certain floating-point types. :-)

enjoy,
Andrew

Re: [patch/rfc] Eliminate TARGET_BYTE_ORDER_SELECTABLE

[Daniel Jacobowitz]

On Sun, Jan 20, 2002 at 01:33:29PM -0500, Andrew Cagney wrote:
> >
> >Woah!  That's neat!  I need to remember that :)
> >
> >And I suppose I of all people shouldn't be griping about allowing more
> >endianness choices.  I have a patch here to support big-endian
> >ARM/Linux.  All I did was change TARGET_BYTE_ORDER_*.
> 
> 
> Delete it :-)  As Michael observed, if the code is written correctly it 
> works from day one.  (Problem is it has taken ~10 years to figure out 
> how to correctly write the code :-)

Well, I need to set TARGET_BYTE_ORDER_DEFAULT.  If you start a cross
debugger without giving it a binary, and attach to a random remote
target, then we need to default to the right one.  Other than that
everything is fine, though!

> Oh, if you think that is neat, just wait until someone adds byte-order 
> information to ``struct type''.  As it is, gdb knows about the byte 
> order of certain floating-point types. :-)

And GCC keeps talking about supporting data types with arbitrary byte
order... :)

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer

Re: [patch/rfc] Eliminate TARGET_BYTE_ORDER_SELECTABLE

[Andrew Cagney]

> On Sun, Jan 20, 2002 at 01:33:29PM -0500, Andrew Cagney wrote:
> 
>> >
>> >Woah!  That's neat!  I need to remember that :)
>> >
>> >And I suppose I of all people shouldn't be griping about allowing more
>> >endianness choices.  I have a patch here to support big-endian
>> >ARM/Linux.  All I did was change TARGET_BYTE_ORDER_*.
> 
>> 
>> 
>> Delete it :-)  As Michael observed, if the code is written correctly it 
>> works from day one.  (Problem is it has taken ~10 years to figure out 
>> how to correctly write the code :-)
> 
> 
> Well, I need to set TARGET_BYTE_ORDER_DEFAULT.  If you start a cross
> debugger without giving it a binary, and attach to a random remote
> target, then we need to default to the right one.  Other than that
> everything is fine, though!


Nope! I'm about to delete TARGET_BYTE_ORDER_DEFAULT.

There is this really nasty bit of code in arch-utils.c that roots around 
the internals of BFD and uses that to determine the initial architecture 
and byte-order.  Doing this ensures that GDB's behavour is better 
aligned with that of BINUTILS.
See arch-utils.c:initialize_current_architecture().

If GDB initializes its self to the wrong byte-order then there is likely 
a bug in BFD.

Did I mention that we live in dangerous times :-)
Andrew

PS: Actually the code isn't that bad.  What makes it nasty is the need 
to prop up the old non-multi-arch behavour.

Re: [patch/rfc] Eliminate TARGET_BYTE_ORDER_SELECTABLE

[Daniel Jacobowitz]

On Sun, Jan 20, 2002 at 02:00:33PM -0500, Andrew Cagney wrote:
> >On Sun, Jan 20, 2002 at 01:33:29PM -0500, Andrew Cagney wrote:
> >
> >>>
> >>>Woah!  That's neat!  I need to remember that :)
> >>>
> >>>And I suppose I of all people shouldn't be griping about allowing more
> >>>endianness choices.  I have a patch here to support big-endian
> >>>ARM/Linux.  All I did was change TARGET_BYTE_ORDER_*.
> >
> >>
> >>
> >>Delete it :-)  As Michael observed, if the code is written correctly it 
> >>works from day one.  (Problem is it has taken ~10 years to figure out 
> >>how to correctly write the code :-)
> >
> >
> >Well, I need to set TARGET_BYTE_ORDER_DEFAULT.  If you start a cross
> >debugger without giving it a binary, and attach to a random remote
> >target, then we need to default to the right one.  Other than that
> >everything is fine, though!
> 
> 
> Nope! I'm about to delete TARGET_BYTE_ORDER_DEFAULT.
> 
> There is this really nasty bit of code in arch-utils.c that roots around 
> the internals of BFD and uses that to determine the initial architecture 
> and byte-order.  Doing this ensures that GDB's behavour is better 
> aligned with that of BINUTILS.
> See arch-utils.c:initialize_current_architecture().
> 
> If GDB initializes its self to the wrong byte-order then there is likely 
> a bug in BFD.

Oh, I see.  I -think- this will work correctly for my targets; I'll
check after you do it.

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer

Re: [patch/rfc] Eliminate TARGET_BYTE_ORDER_SELECTABLE

[Andrew Cagney]

> Nope! I'm about to delete TARGET_BYTE_ORDER_DEFAULT.
>> 
>> There is this really nasty bit of code in arch-utils.c that roots around 
>> the internals of BFD and uses that to determine the initial architecture 
>> and byte-order.  Doing this ensures that GDB's behavour is better 
>> aligned with that of BINUTILS.
>> See arch-utils.c:initialize_current_architecture().
>> 
>> If GDB initializes its self to the wrong byte-order then there is likely 
>> a bug in BFD.
> 
> 
> Oh, I see.  I -think- this will work correctly for my targets; I'll
> check after you do it.


BTW, the MIPS has been using this since:

Wed Jun  7 18:27:51 2000  Andrew Cagney  <cagney@b1.cygnus.com>

        * configure.in (DEFAULT_BFD_ARCH, DEFAULT_BFD_VEC): Use config.bfd
        to determine the default architecture / target.
        * acconfig (DEFAULT_BFD_ARCH, DEFAULT_BFD_VEC): Add.
        * configure, config.in: Regenerate.
        
        * arch-utils.c (set_endian): Better separate multi-arch and non-
        multi-arch cases.
        (set_endian_from_file): Call internal_error when multi-arch.
        (initialize_current_architecture): Rewrite logic selecting a byte
        order.  Use DEFAULT_BFD_ARCH DEFAULT_BFD_VEC.
        (version.h): Include.

        * config/mips/tm-mips.h, config/mips/tm-bigmips64.h,
        config/mips/tm-bigmips.h: Delete definition of
        TARGET_BYTE_ORDER_DEFAULT.


Andrew

Re: [patch/rfc] Eliminate TARGET_BYTE_ORDER_SELECTABLE

[Andrew Cagney]

> 2002-01-19  Andrew Cagney  <ac131313@redhat.com>
> 
> * remote-sim.c (gdbsim_open): Simplify code testing the macro
> 	TARGET_BYTE_ORDER_SELECTABLE_P.  Assume the target is always
> 	byte-order selectable.
> 	* sparc-tdep.c (sparc_target_architecture_hook): Ditto.
> 	* arch-utils.c: Ditto.
> 	(set_endian): Ditto.
> 	(set_endian_from_file): Ditto.
> 	* gdbserver/low-sim.c (create_inferior): Ditto.
> 	* gdbarch.sh: Ditto.
> 	* gdbarch.h: Re-generate.
> 	* config/powerpc/tm-ppc-eabi.h (TARGET_BYTE_ORDER_SELECTABLE_P): 
> 	* config/sparc/tm-sparclite.h (TARGET_BYTE_ORDER_SELECTABLE): 
> 	* config/sparc/tm-sparclet.h (TARGET_BYTE_ORDER_SELECTABLE): 
> 	* config/mcore/tm-mcore.h (TARGET_BYTE_ORDER_SELECTABLE_P): 
> 	* config/arm/tm-wince.h (TARGET_BYTE_ORDER_SELECTABLE_P): 
> 	* config/arm/tm-linux.h (TARGET_BYTE_ORDER_SELECTABLE_P): 
> 	* config/arc/tm-arc.h (TARGET_BYTE_ORDER_SELECTABLE): 
> 	* config/arm/tm-arm.h (TARGET_BYTE_ORDER_SELECTABLE_P): Delete
> 	macro definition.
> 	* config/mips/tm-wince.h: Remove #undef of macro
> 	TARGET_BYTE_ORDER_SELECTABLE.
> 	* config/sh/tm-wince.h: Ditto.
> 


I've checked this one in.  I guess I now get to find out how the 
non-multi-arch targets go.

Andrew