2012-03-28 Pedro Alves <palves@redhat.com>

* linux-ia64-low.c (ia64_regmap): Map IA64_EC_REGNUM to PT_AR_EC.
	(IA64_GR0_REGNUM, IA64_FR0_REGNUM)
	(IA64_FR1_REGNUM): New defines.
	(ia64_fetch_register): New.
	(the_low_target): Install it.
	* linux-low.h (struct linux_target_ops) <fetch_register>: New
	field.
	* linux-low.c (linux_fetch_registers): Try the
	the_low_target.fetch_register hook first.

	* linux-arm-low.c (the_low_target): Adjust.
	* linux-bfin-low.c (the_low_target): Adjust.
	* linux-cris-low.c (the_low_target): Adjust.
	* linux-crisv32-low.c (the_low_target): Adjust.
	* linux-m32r-low.c (the_low_target): Adjust.
	* linux-m68k-low.c (the_low_target): Adjust.
	* linux-mips-low.c (the_low_target): Adjust.
	* linux-ppc-low.c (the_low_target): Adjust.
	* linux-s390-low.c (the_low_target): Adjust.
	* linux-sh-low.c (the_low_target): Adjust.
	* linux-sparc-low.c (the_low_target): Adjust.
	* linux-tic6x-low.c (the_low_target): Adjust.
	* linux-x86-low.c (the_low_target): Adjust.
	* linux-xtensa-low.c (the_low_target): Adjust.

gdb/gdbserver/ChangeLog

@@ -1,3 +1,30 @@
+2012-03-28  Pedro Alves  <palves@redhat.com>
+
+	* linux-ia64-low.c (ia64_regmap): Map IA64_EC_REGNUM to PT_AR_EC.
+	(IA64_GR0_REGNUM, IA64_FR0_REGNUM)
+	(IA64_FR1_REGNUM): New defines.
+	(ia64_fetch_register): New.
+	(the_low_target): Install it.
+	* linux-low.h (struct linux_target_ops) <fetch_register>: New
+	field.
+	* linux-low.c (linux_fetch_registers): Try the
+	the_low_target.fetch_register hook first.
+
+	* linux-arm-low.c (the_low_target): Adjust.
+	* linux-bfin-low.c (the_low_target): Adjust.
+	* linux-cris-low.c (the_low_target): Adjust.
+	* linux-crisv32-low.c (the_low_target): Adjust.
+	* linux-m32r-low.c (the_low_target): Adjust.
+	* linux-m68k-low.c (the_low_target): Adjust.
+	* linux-mips-low.c (the_low_target): Adjust.
+	* linux-ppc-low.c (the_low_target): Adjust.
+	* linux-s390-low.c (the_low_target): Adjust.
+	* linux-sh-low.c (the_low_target): Adjust.
+	* linux-sparc-low.c (the_low_target): Adjust.
+	* linux-tic6x-low.c (the_low_target): Adjust.
+	* linux-x86-low.c (the_low_target): Adjust.
+	* linux-xtensa-low.c (the_low_target): Adjust.
+
 2012-03-26  Pedro Alves  <palves@redhat.com>
 
 	* server.c (handle_qxfer_libraries): Don't bail early if

gdb/gdbserver/linux-arm-low.c

@@ -837,6 +837,7 @@ struct linux_target_ops the_low_target = {
   NULL,
   arm_cannot_fetch_register,
   arm_cannot_store_register,
+  NULL, /* fetch_register */
   arm_get_pc,
   arm_set_pc,
 

gdb/gdbserver/linux-bfin-low.c

@@ -97,6 +97,7 @@ struct linux_target_ops the_low_target = {
   NULL,
   bfin_cannot_fetch_register,
   bfin_cannot_store_register,
+  NULL, /* fetch_register */
   bfin_get_pc,
   bfin_set_pc,
   bfin_breakpoint,

gdb/gdbserver/linux-cris-low.c

@@ -115,6 +115,7 @@ struct linux_target_ops the_low_target = {
   NULL,
   cris_cannot_fetch_register,
   cris_cannot_store_register,
+  NULL, /* fetch_register */
   cris_get_pc,
   cris_set_pc,
   (const unsigned char *) &cris_breakpoint,

gdb/gdbserver/linux-crisv32-low.c

@@ -377,6 +377,7 @@ struct linux_target_ops the_low_target = {
   NULL,
   NULL,
   NULL,
+  NULL, /* fetch_register */
   cris_get_pc,
   cris_set_pc,
   (const unsigned char *) &cris_breakpoint,

gdb/gdbserver/linux-ia64-low.c

@@ -256,7 +256,7 @@ static int ia64_regmap[] =
     -1, -1, -1, -1, -1, -1, -1, -1, -1,
     PT_AR_PFS,
     PT_AR_LC,
-    -1,		/* Not available: EC, the Epilog Count register */
+    PT_AR_EC,
     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
@@ -278,6 +278,48 @@ ia64_cannot_fetch_register (int regno)
   return 0;
 }
 
+/* GDB register numbers.  */
+#define IA64_GR0_REGNUM		0
+#define IA64_FR0_REGNUM		128
+#define IA64_FR1_REGNUM		129
+
+static int
+ia64_fetch_register (struct regcache *regcache, int regnum)
+{
+  /* r0 cannot be fetched but is always zero.  */
+  if (regnum == IA64_GR0_REGNUM)
+    {
+      const gdb_byte zero[8] = { 0 };
+
+      gdb_assert (sizeof (zero) == register_size (regnum));
+      supply_register (regcache, regnum, zero);
+      return 1;
+    }
+
+  /* fr0 cannot be fetched but is always zero.  */
+  if (regnum == IA64_FR0_REGNUM)
+    {
+      const gdb_byte f_zero[16] = { 0 };
+
+      gdb_assert (sizeof (f_zero) == register_size (regnum));
+      supply_register (regcache, regnum, f_zero);
+      return 1;
+    }
+
+  /* fr1 cannot be fetched but is always one (1.0).  */
+  if (regnum == IA64_FR1_REGNUM)
+    {
+      const gdb_byte f_one[16] =
+	{ 0, 0, 0, 0, 0, 0, 0, 0x80, 0xff, 0xff, 0, 0, 0, 0, 0, 0 };
+
+      gdb_assert (sizeof (f_one) == register_size (regnum));
+      supply_register (regcache, regnum, f_one);
+      return 1;
+    }
+
+  return 0;
+}
+
 struct linux_target_ops the_low_target = {
   init_registers_ia64,
   ia64_num_regs,
@@ -285,4 +327,5 @@ struct linux_target_ops the_low_target = {
   NULL,
   ia64_cannot_fetch_register,
   ia64_cannot_store_register,
+  ia64_fetch_register,
 };

gdb/gdbserver/linux-low.c

@@ -4271,11 +4271,19 @@ linux_fetch_registers (struct regcache *regcache, int regno)
 
   if (regno == -1)
     {
+      if (the_low_target.fetch_register != NULL)
+	for (regno = 0; regno < the_low_target.num_regs; regno++)
+	  (*the_low_target.fetch_register) (regcache, regno);
+
       all = regsets_fetch_inferior_registers (regcache);
-      usr_fetch_inferior_registers (regcache, regno, all);
+      usr_fetch_inferior_registers (regcache, -1, all);
     }
   else
     {
+      if (the_low_target.fetch_register != NULL
+	  && (*the_low_target.fetch_register) (regcache, regno))
+	return;
+
       use_regsets = linux_register_in_regsets (regno);
       if (use_regsets)
 	all = regsets_fetch_inferior_registers (regcache);

gdb/gdbserver/linux-low.h

@@ -81,6 +81,14 @@ struct linux_target_ops
      store the register, and 2 if failure to store the register
      is acceptable.  */
   int (*cannot_store_register) (int);
+
+  /* Hook to fetch a register in some non-standard way.  Used for
+     example by backends that have read-only registers with hardcoded
+     values (e.g., IA64's gr0/fr0/fr1).  Returns true if register
+     REGNO was supplied, false if not, and we should fallback to the
+     standard ptrace methods.  */
+  int (*fetch_register) (struct regcache *regcache, int regno);
+
   CORE_ADDR (*get_pc) (struct regcache *regcache);
   void (*set_pc) (struct regcache *regcache, CORE_ADDR newpc);
   const unsigned char *breakpoint;

gdb/gdbserver/linux-m32r-low.c

@@ -94,6 +94,7 @@ struct linux_target_ops the_low_target = {
   NULL,
   m32r_cannot_fetch_register,
   m32r_cannot_store_register,
+  NULL, /* fetch_register */
   m32r_get_pc,
   m32r_set_pc,
   (const unsigned char *) &m32r_breakpoint,

gdb/gdbserver/linux-m68k-low.c

@@ -182,6 +182,7 @@ struct linux_target_ops the_low_target = {
   NULL,
   m68k_cannot_fetch_register,
   m68k_cannot_store_register,
+  NULL, /* fetch_register */
   m68k_get_pc,
   m68k_set_pc,
   m68k_breakpoint,

gdb/gdbserver/linux-mips-low.c

@@ -430,6 +430,7 @@ struct linux_target_ops the_low_target = {
   NULL,
   mips_cannot_fetch_register,
   mips_cannot_store_register,
+  NULL, /* fetch_register */
   mips_get_pc,
   mips_set_pc,
   (const unsigned char *) &mips_breakpoint,

gdb/gdbserver/linux-ppc-low.c

@@ -613,6 +613,7 @@ struct linux_target_ops the_low_target = {
   NULL,
   ppc_cannot_fetch_register,
   ppc_cannot_store_register,
+  NULL, /* fetch_register */
   ppc_get_pc,
   ppc_set_pc,
   (const unsigned char *) &ppc_breakpoint,

gdb/gdbserver/linux-s390-low.c

@@ -464,6 +464,7 @@ struct linux_target_ops the_low_target = {
   NULL,
   s390_cannot_fetch_register,
   s390_cannot_store_register,
+  NULL, /* fetch_register */
   s390_get_pc,
   s390_set_pc,
   s390_breakpoint,

gdb/gdbserver/linux-sh-low.c

@@ -115,6 +115,7 @@ struct linux_target_ops the_low_target = {
   NULL,
   sh_cannot_fetch_register,
   sh_cannot_store_register,
+  NULL, /* fetch_register */
   sh_get_pc,
   sh_set_pc,
   (const unsigned char *) &sh_breakpoint,

gdb/gdbserver/linux-sparc-low.c

@@ -284,6 +284,7 @@ struct linux_target_ops the_low_target = {
   NULL,
   sparc_cannot_fetch_register,
   sparc_cannot_store_register,
+  NULL, /* fetch_register */
   sparc_get_pc,
   /* No sparc_set_pc is needed.  */
   NULL,

gdb/gdbserver/linux-tic6x-low.c

@@ -324,6 +324,7 @@ struct linux_target_ops the_low_target = {
   NULL,
   tic6x_cannot_fetch_register,
   tic6x_cannot_store_register,
+  NULL, /* fetch_register */
   tic6x_get_pc,
   tic6x_set_pc,
   (const unsigned char *) &tic6x_breakpoint,

gdb/gdbserver/linux-x86-low.c

@@ -2969,6 +2969,7 @@ struct linux_target_ops the_low_target =
   NULL,
   NULL,
   NULL,
+  NULL, /* fetch_register */
   x86_get_pc,
   x86_set_pc,
   x86_breakpoint,

gdb/gdbserver/linux-xtensa-low.c

@@ -183,6 +183,7 @@ struct linux_target_ops the_low_target = {
   NULL,
   0,
   0,
+  NULL, /* fetch_register */
   xtensa_get_pc,
   xtensa_set_pc,
   xtensa_breakpoint,