[RFA:] Minor sim callback endian cleanup.

[Hans-Peter Nilsson <hans-peter dot nilsson at axis dot com>]

The supposedly-sim-independent sim/common/callback.c and syscall.c
(from sim/common/syscall.c:
/* This interface isn't intended to be specific to any particular kind
   of remote (hardware, simulator, whatever).  As such, support for it
   (e.g. sim/common/callback.c) should *not* live in the simulator source
   tree, nor should it live in the gdb source tree.  K&R C must be
   supported.  */
)
have no idea what the endian of the target is, and still are
supposed to store multi-byte values correctly without access to
proper multibyte-value-store functions.  Currently,
little-endian is assumed when storing struct stat members, which
of course is just broken.  This patch introduces a member of
host_callback to hold the endianness of the target.  Because of
sim-independentness those files must not include sim-config.h to
access CURRENT_TARGET_BYTE_ORDER.  Oh well.  I blissfully ignore
the possibility of different endian types (16-bit within 32-bit
different to 8-bit within 16-bit) but so does the rest of sim/.

Tested together with other dependent stuff using the CRIS sim.
Test-built on m32r-sim, arm-sim and frv-sim with this patch
only.

include/gdb:
	* callback.h (struct host_callback_struct): New member
	target_big_endian.
	(cb_store_target_endian): Prototype.

sim/common:
	* callback.c (default_callback): Initialize target_big_endian.
	(cb_store_target_endian): Renamed from store, new first parameter
	host_callback *cb, drop last parameter big_p.  Take endianness
	from cb.
	(cb_host_to_target_stat): Change to use cb_store_target_endian.
	Remove variable big_p.
	* nrun.c (main): Initialize default_callback.target_big_endian.

Only in .: .xdiff-directory
diff -rup /n/slask/hp_tmp/gdb-6.3.50_20041211/./include/gdb/callback.h ./include/gdb/callback.h
--- /n/slask/hp_tmp/gdb-6.3.50_20041211/./include/gdb/callback.h	Fri Jun 25 18:48:01 2004
+++ ./include/gdb/callback.h	Sun Dec 12 06:06:29 2004
@@ -150,6 +150,9 @@ struct host_callback_struct 
      Example: "st_dev,4:st_ino,4:st_mode,4:..."  */
   const char *stat_map;
 
+  /* Nonzero for a big-endian target.  */
+  int target_big_endian;
+
   /* Marker for those wanting to do sanity checks.
      This should remain the last member of this struct to help catch
      miscompilation errors. */
@@ -272,6 +275,9 @@ int cb_host_to_target_signal PARAMS ((ho
    If stat struct ptr is NULL, just compute target stat struct size.
    Result is size of target stat struct or 0 if error.  */
 int cb_host_to_target_stat PARAMS ((host_callback *, const struct stat *, PTR));
+
+/* Translate a value to target endian.  */
+void cb_store_target_endian PARAMS ((host_callback *, char *, int, long));
 
 /* Perform a system call.  */
 CB_RC cb_syscall PARAMS ((host_callback *, CB_SYSCALL *));
Only in ./include/gdb: callback.h~
Only in ./sim/common: ChangeLog.hp
diff -rup /n/slask/hp_tmp/gdb-6.3.50_20041211/./sim/common/callback.c ./sim/common/callback.c
--- /n/slask/hp_tmp/gdb-6.3.50_20041211/./sim/common/callback.c	Sat Dec  4 00:34:55 2004
+++ ./sim/common/callback.c	Sun Dec 12 05:17:26 2004
@@ -615,6 +615,9 @@ host_callback default_callback =
   0, /* signal_map */
   0, /* stat_map */
 	
+  /* Defaults expected to be overridden at initialization, where needed.  */
+  0, /* target_big_endian */
+
   HOST_CALLBACK_MAGIC,
 };
 
@@ -746,17 +749,17 @@ cb_target_to_host_open (cb, target_val)
   return host_val;
 }
 
-/* Utility for cb_host_to_target_stat to store values in the target's
+/* Utility for e.g. cb_host_to_target_stat to store values in the target's
    stat struct.  */
 
-static void
-store (p, size, val, big_p)
+void
+cb_store_target_endian (cb, p, size, val)
+     host_callback *cb;
      char *p;
      int size;
      long val; /* ??? must be as big as target word size */
-     int big_p;
 {
-  if (big_p)
+  if (cb->target_big_endian)
     {
       p += size;
       while (size-- > 0)
@@ -790,7 +793,6 @@ cb_host_to_target_stat (cb, hs, ts)
 {
   const char *m = cb->stat_map;
   char *p;
-  int big_p = 0;
 
   if (hs == NULL)
     ts = NULL;
@@ -822,7 +824,7 @@ cb_host_to_target_stat (cb, hs, ts)
 #undef ST_x
 #define ST_x(FLD)					\
 	  else if (strncmp (m, #FLD, q - m) == 0)	\
-	    store (p, size, hs->FLD, big_p)
+	    cb_store_target_endian (cb, p, size, hs->FLD)
 
 #ifdef HAVE_STRUCT_STAT_ST_DEV
 	  ST_x (st_dev);
@@ -866,7 +868,8 @@ cb_host_to_target_stat (cb, hs, ts)
 #undef ST_x
 	  /* FIXME:wip */
 	  else
-	    store (p, size, 0, big_p); /* unsupported field, store 0 */
+	    /* Unsupported field, store 0.  */
+	    cb_store_target_endian (cb, p, size, 0);
 	}
 
       p += size;
Only in ./sim/common: callback.c.orig
Only in ./sim/common: callback.c~
diff -rup /n/slask/hp_tmp/gdb-6.3.50_20041211/./sim/common/nrun.c ./sim/common/nrun.c
--- /n/slask/hp_tmp/gdb-6.3.50_20041211/./sim/common/nrun.c	Wed Dec  8 01:40:30 2004
+++ ./sim/common/nrun.c	Sun Dec 12 05:17:26 2004
@@ -82,6 +82,11 @@ main (int argc, char **argv)
       abort ();
     }
 
+  /* We can't set the endianness in the callback structure until
+     sim_config is called, which happens in sim_open.  */
+  default_callback.target_big_endian
+    = CURRENT_TARGET_BYTE_ORDER == BIG_ENDIAN;
+
   /* Was there a program to run?  */
   prog_argv = STATE_PROG_ARGV (sd);
   prog_bfd = STATE_PROG_BFD (sd);

brgds, H-P