[PATCH] Add support for FR-V FDPIC executables

[Kevin Buettner <kevinb at redhat dot com>]

I've just committed the patch below.

It adds support for detecting FDPIC (shared library ABI) executables. 
It also adds two fake registers which are used by the upcoming FR-V
shared library support.  These fake registers occupy unused slots and
do not affect existing clients of the FR-V (remote protocol) register
layout.

	* Makefile.in (elf_frv_h, frv_tdep_h): Define.
	(frv-tdep.o): Update dependencies.
	* frv-tdep.h: New file.
	* frv-tdep.c (elf-bfd.h, elf/frv.h, osabi.h, frv-tdep.h): Include.
	(fdpic_loadmap_exec_regnum, fdpic_loadmap_interp_regnum): New
	constants.
	(struct gdbarch_tdep): Add new member ``frv_abi''.
	(frv_abi, frv_fdpic_loadmap_addresses, set_variant_abi_fdpic): New
	functions.
	(new_variant): Set ``frv_abi'' field.
	(gdb_arch_init): Detect FDPIC executables.

Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/Makefile.in,v
retrieving revision 1.518
diff -u -p -r1.518 Makefile.in
--- Makefile.in	28 Feb 2004 18:04:36 -0000	1.518
+++ Makefile.in	13 Mar 2004 00:05:30 -0000
@@ -569,6 +569,7 @@ elf_reloc_macros_h =	$(INCLUDE_DIR)/elf/
 elf_sh_h =	$(INCLUDE_DIR)/elf/sh.h
 elf_arm_h =	$(INCLUDE_DIR)/elf/arm.h $(elf_reloc_macros_h)
 elf_bfd_h =	$(BFD_SRC)/elf-bfd.h
+elf_frv_h =	$(INCLUDE_DIR)/elf/frv.h $(elf_reloc_macros_h)
 libaout_h =	$(BFD_SRC)/libaout.h
 libbfd_h =	$(BFD_SRC)/libbfd.h
 remote_sim_h =	$(INCLUDE_DIR)/gdb/remote-sim.h
@@ -658,6 +659,7 @@ f_lang_h = f-lang.h
 frame_base_h = frame-base.h
 frame_h = frame.h
 frame_unwind_h = frame-unwind.h $(frame_h)
+frv_tdep_h = frv-tdep.h
 gdbarch_h = gdbarch.h
 gdb_assert_h = gdb_assert.h
 gdbcmd_h = gdbcmd.h $(command_h) $(ui_out_h)
@@ -1769,6 +1771,7 @@ frv-tdep.o: frv-tdep.c $(defs_h) $(gdb_s
 	$(arch_utils_h) $(regcache_h) $(frame_h) $(frame_unwind_h) \
 	$(frame_base_h) $(trad_frame_h) $(dis_asm_h) $(gdb_assert_h) \
 	$(sim_regno_h) $(gdb_sim_frv_h) $(opcodes_frv_desc_h) $(symtab_h)
+	$(elf_bfd_h) $(elf_frv_h) $(osabi_h) $(frv_tdep_h)
 f-typeprint.o: f-typeprint.c $(defs_h) $(gdb_obstack_h) $(bfd_h) $(symtab_h) \
 	$(gdbtypes_h) $(expression_h) $(value_h) $(gdbcore_h) $(target_h) \
 	$(f_lang_h) $(gdb_string_h)
Index: frv-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/frv-tdep.c,v
retrieving revision 1.72
diff -u -p -r1.72 frv-tdep.c
--- frv-tdep.c	17 Feb 2004 15:21:21 -0000	1.72
+++ frv-tdep.c	13 Mar 2004 00:05:30 -0000
@@ -34,6 +34,10 @@
 #include "gdb/sim-frv.h"
 #include "opcodes/frv-desc.h"	/* for the H_SPR_... enums */
 #include "symtab.h"
+#include "elf-bfd.h"
+#include "elf/frv.h"
+#include "osabi.h"
+#include "frv-tdep.h"
 
 extern void _initialize_frv_tdep (void);
 
@@ -69,6 +73,8 @@ enum {
   psr_regnum = 129,
   ccr_regnum = 130,
   cccr_regnum = 131,
+  fdpic_loadmap_exec_regnum = 132,
+  fdpic_loadmap_interp_regnum = 133,
   tbr_regnum = 135,
   brr_regnum = 136,
   dbar0_regnum = 137,
@@ -129,6 +135,9 @@ struct frv_unwind_cache		/* was struct f
    Fortran.  */
 struct gdbarch_tdep
 {
+  /* Which ABI is in use?  */
+  enum frv_abi frv_abi;
+
   /* How many general-purpose registers does this variant have?  */
   int num_gprs;
 
@@ -147,6 +156,41 @@ struct gdbarch_tdep
 
 #define CURRENT_VARIANT (gdbarch_tdep (current_gdbarch))
 
+/* Return the FR-V ABI associated with GDBARCH.  */
+enum frv_abi
+frv_abi (struct gdbarch *gdbarch)
+{
+  return gdbarch_tdep (gdbarch)->frv_abi;
+}
+
+/* Fetch the interpreter and executable loadmap addresses (for shared
+   library support) for the FDPIC ABI.  Return 0 if successful, -1 if
+   not.  (E.g, -1 will be returned if the ABI isn't the FDPIC ABI.)  */
+int
+frv_fdpic_loadmap_addresses (struct gdbarch *gdbarch, CORE_ADDR *interp_addr,
+                             CORE_ADDR *exec_addr)
+{
+  if (frv_abi (gdbarch) != FRV_ABI_FDPIC)
+    return -1;
+  else
+    {
+      if (interp_addr != NULL)
+	{
+	  ULONGEST val;
+	  regcache_cooked_read_unsigned (current_regcache,
+					 fdpic_loadmap_interp_regnum, &val);
+	  *interp_addr = val;
+	}
+      if (exec_addr != NULL)
+	{
+	  ULONGEST val;
+	  regcache_cooked_read_unsigned (current_regcache,
+					 fdpic_loadmap_exec_regnum, &val);
+	  *exec_addr = val;
+	}
+      return 0;
+    }
+}
 
 /* Allocate a new variant structure, and set up default values for all
    the fields.  */
@@ -160,6 +204,7 @@ new_variant (void)
   var = xmalloc (sizeof (*var));
   memset (var, 0, sizeof (*var));
   
+  var->frv_abi = FRV_ABI_EABI;
   var->num_gprs = 64;
   var->num_fprs = 64;
   var->num_hw_watchpoints = 0;
@@ -238,6 +283,13 @@ set_variant_num_fprs (struct gdbarch_tde
     }
 }
 
+static void
+set_variant_abi_fdpic (struct gdbarch_tdep *var)
+{
+  var->frv_abi = FRV_ABI_FDPIC;
+  var->register_names[fdpic_loadmap_exec_regnum] = xstrdup ("loadmap_exec");
+  var->register_names[fdpic_loadmap_interp_regnum] = xstrdup ("loadmap_interp");
+}
 
 static const char *
 frv_register_name (int reg)
@@ -1276,6 +1328,7 @@ frv_gdbarch_init (struct gdbarch_info in
 {
   struct gdbarch *gdbarch;
   struct gdbarch_tdep *var;
+  int elf_flags = 0;
 
   /* Check to see if we've already built an appropriate architecture
      object for this executable.  */
@@ -1305,7 +1358,14 @@ frv_gdbarch_init (struct gdbarch_info in
       /* Never heard of this variant.  */
       return 0;
     }
-  
+
+  /* Extract the ELF flags, if available.  */
+  if (info.abfd && bfd_get_flavour (info.abfd) == bfd_target_elf_flavour)
+    elf_flags = elf_elfheader (info.abfd)->e_flags;
+
+  if (elf_flags & EF_FRV_FDPIC)
+    set_variant_abi_fdpic (var);
+
   gdbarch = gdbarch_alloc (&info, var);
 
   set_gdbarch_short_bit (gdbarch, 16);
Index: frv-tdep.h
===================================================================
RCS file: frv-tdep.h
diff -N frv-tdep.h
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ frv-tdep.h	13 Mar 2004 00:05:30 -0000
@@ -0,0 +1,35 @@
+/* Architecture-dependent code for the Fujitsu FR-V, for GDB, the GNU Debugger.
+   Copyright 2004 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+/* Enumerate the possible ABIs for FR-V.  */
+enum frv_abi
+  {
+    FRV_ABI_EABI,
+    FRV_ABI_FDPIC
+  };
+
+/* Return the FR-V ABI associated with GDBARCH.  */
+enum frv_abi frv_abi (struct gdbarch *gdbarch);
+
+/* Fetch the interpreter and executable loadmap addresses (for shared
+   library support) for the FDPIC ABI.  Return 0 if successful, -1 if
+   not.  (E.g, -1 will be returned if the ABI isn't the FDPIC ABI.)  */
+int frv_fdpic_loadmap_addresses (struct gdbarch *gdbarch,
+                                 CORE_ADDR *interp_addr, CORE_ADDR *exec_addr);