Add arm-symbianelf support.

Add arm-symbianelf support.

[Pedro Alves]

This patch of Daniel's adds basic support for arm-symbianelf
to gdb.

Daniel, do you think the arm_symbian_osabi_sniffer is
still sufficiently tight to not cause problems in
--enable-target=all builds?  Otherwise, this looks
good to me.  :-)

A short NEWS blurb is missing; I'll handle that next.

-- 
Pedro Alves

2010-02-25  Daniel Jacobowitz  <dan@codesourcery.com>
 
	Symbian config

	gdb/
	* arm-symbian-tdep.c: New.
	* configure.tgt (arm*-*-symbianelf*): New target.
	(*-*-symbianelf*): New OS.
	* osabi.c (gdb_osabi_names): Add Symbian.
	* defs.h (gdb_osabi): Add GDB_OSABI_SYMBIAN.
	* Makefile.in (ALL_TARGET_OBJS): Add arm-symbian-tdep.o.
	(ALLDEPFILES): Add arm-symbian-tdep.c.

---
 gdb/Makefile.in        |    5 +-
 gdb/arm-symbian-tdep.c |  121 +++++++++++++++++++++++++++++++++++++++++++++++++
 gdb/configure.tgt      |    6 ++
 gdb/defs.h             |    3 -
 gdb/osabi.c            |    3 -
 5 files changed, 132 insertions(+), 6 deletions(-)

Index: src/gdb/arm-symbian-tdep.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ src/gdb/arm-symbian-tdep.c	2010-02-25 19:16:33.000000000 +0000
@@ -0,0 +1,121 @@
+/* ARM Symbian OS target support.
+
+   Copyright (C) 2008, 2009, 2010
+   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 3 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, see <http://www.gnu.org/licenses/>.  */
+
+#include "defs.h"
+#include "frame.h"
+#include "objfiles.h"
+#include "osabi.h"
+#include "solib.h"
+#include "solib-target.h"
+#include "target.h"
+#include "elf-bfd.h"
+
+/* If PC is in a DLL import stub, return the address of the `real'
+   function belonging to the stub.  */
+
+CORE_ADDR
+arm_symbian_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
+{
+  struct gdbarch *gdbarch;
+  enum bfd_endian byte_order;
+  ULONGEST insn;
+  CORE_ADDR dest;
+  gdb_byte buf[4];
+
+  if (!in_plt_section (pc, NULL))
+    return 0;
+
+  if (target_read_memory (pc, buf, 4) != 0)
+    return 0;
+
+  gdbarch = get_frame_arch (frame);
+  byte_order = gdbarch_byte_order (gdbarch);
+
+  /* ldr pc, [pc, #-4].  */
+  insn = extract_unsigned_integer (buf, 4, byte_order);
+  if (insn != 0xe51ff004)
+    return 0;
+
+  if (target_read_memory (pc + 4, buf, 4) != 0)
+    return 0;
+
+  dest = extract_unsigned_integer (buf, 4, byte_order);
+  return gdbarch_addr_bits_remove (gdbarch, dest);
+}
+
+static void
+arm_symbian_init_abi (struct gdbarch_info info,
+		      struct gdbarch *gdbarch)
+{
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+  /* Shared library handling.  */
+  set_gdbarch_skip_trampoline_code (gdbarch, arm_symbian_skip_trampoline_code);
+
+  set_solib_ops (gdbarch, &solib_target_so_ops);
+}
+
+/* Recognize Symbian object files.  */
+
+static enum gdb_osabi
+arm_symbian_osabi_sniffer (bfd *abfd)
+{
+  Elf_Internal_Phdr *phdrs, **segments;
+  long phdrs_size;
+  int num_phdrs, i;
+
+  /* Symbian executables are always shared objects (ET_DYN).  */
+  if (elf_elfheader (abfd)->e_type == ET_EXEC)
+    return GDB_OSABI_UNKNOWN;
+
+  if (elf_elfheader (abfd)->e_ident[EI_OSABI] != ELFOSABI_NONE)
+    return GDB_OSABI_UNKNOWN;
+
+  /* Check for the ELF headers not being part of any PT_LOAD segment.
+     Symbian is the only GDB supported (or GNU binutils supported) ARM
+     target which uses a postlinker to flatten ELF files, dropping the
+     ELF dynamic info in the process.  */
+  phdrs_size = bfd_get_elf_phdr_upper_bound (abfd);
+  if (phdrs_size == -1)
+    return GDB_OSABI_UNKNOWN;
+
+  phdrs = alloca (phdrs_size);
+  num_phdrs = bfd_get_elf_phdrs (abfd, phdrs);
+  if (num_phdrs == -1)
+    return GDB_OSABI_UNKNOWN;
+
+  for (i = 0; i < num_phdrs; i++)
+    if (phdrs[i].p_type == PT_LOAD && phdrs[i].p_offset == 0)
+      return GDB_OSABI_UNKNOWN;
+
+  /* Looks like a Symbian binary.  */
+  return GDB_OSABI_SYMBIAN;
+}
+
+void
+_initialize_arm_symbian_tdep (void)
+{
+  gdbarch_register_osabi_sniffer (bfd_arch_arm,
+				  bfd_target_elf_flavour,
+				  arm_symbian_osabi_sniffer);
+
+  gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_SYMBIAN,
+			  arm_symbian_init_abi);
+}
Index: src/gdb/configure.tgt
===================================================================
--- src.orig/gdb/configure.tgt	2010-01-20 14:17:35.000000000 +0000
+++ src/gdb/configure.tgt	2010-02-25 19:04:41.000000000 +0000
@@ -91,6 +91,10 @@ arm*-*-openbsd*)
 	gdb_target_obs="arm-tdep.o armbsd-tdep.o armobsd-tdep.o obsd-tdep.o \
 			corelow.o solib.o solib-svr4.o"
 	;;
+arm*-*-symbianelf*)
+	# Target: SymbianOS/arm
+	gdb_target_obs="arm-tdep.o solib-target.o arm-symbian-tdep.o"
+	;;
 arm*-*-* | thumb*-*-* | strongarm*-*-* | xscale-*-*)
 	# Target: ARM embedded system
 	gdb_target_obs="arm-tdep.o"
@@ -626,4 +630,6 @@ m68*-*-openbsd* | m88*-*-openbsd* | vax-
 *-*-mingw* | *-*-cygwin*)
 		gdb_osabi=GDB_OSABI_CYGWIN ;;
 *-*-dicos*)	gdb_osabi=GDB_OSABI_DICOS ;;
+*-*-symbianelf*)
+		gdb_osabi=GDB_OSABI_SYMBIAN ;;
 esac
Index: src/gdb/osabi.c
===================================================================
--- src.orig/gdb/osabi.c	2010-01-05 11:46:46.000000000 +0000
+++ src/gdb/osabi.c	2010-02-25 18:47:18.000000000 +0000
@@ -67,13 +67,12 @@ static const char * const gdb_osabi_name
   "Interix",
   "HP/UX ELF",
   "HP/UX SOM",
-
   "QNX Neutrino",
-
   "Cygwin",
   "AIX",
   "DICOS",
   "Darwin",
+  "Symbian",
 
   "<invalid>"
 };
Index: src/gdb/Makefile.in
===================================================================
--- src.orig/gdb/Makefile.in	2010-02-24 23:10:20.000000000 +0000
+++ src/gdb/Makefile.in	2010-02-25 18:51:02.000000000 +0000
@@ -488,7 +488,8 @@ ALL_64_TARGET_OBS = \
 
 # All other target-dependent objects files (used with --enable-targets=all).
 ALL_TARGET_OBS = \
-	armbsd-tdep.o arm-linux-tdep.o armnbsd-tdep.o armobsd-tdep.o \
+	armbsd-tdep.o arm-linux-tdep.o arm-symbian-tdep.o \
+	armnbsd-tdep.o armobsd-tdep.o \
 	arm-tdep.o arm-wince-tdep.o \
 	avr-tdep.o \
 	cris-tdep.o \
@@ -1406,7 +1407,7 @@ ALLDEPFILES = \
 	amd64-dicos-tdep.c \
 	amd64-linux-nat.c amd64-linux-tdep.c \
 	amd64-sol2-tdep.c \
-	arm-linux-nat.c arm-linux-tdep.c arm-tdep.c \
+	arm-linux-nat.c arm-linux-tdep.c arm-symbian-tdep.c arm-tdep.c \
 	armnbsd-nat.c armbsd-tdep.c armnbsd-tdep.c armobsd-tdep.c \
 	avr-tdep.c \
 	bsd-uthread.c bsd-kvm.c \
Index: src/gdb/defs.h
===================================================================
--- src.orig/gdb/defs.h	2010-02-17 19:41:33.000000000 +0000
+++ src/gdb/defs.h	2010-02-25 18:47:18.000000000 +0000
@@ -969,13 +969,12 @@ enum gdb_osabi
   GDB_OSABI_INTERIX,
   GDB_OSABI_HPUX_ELF,
   GDB_OSABI_HPUX_SOM,
-
   GDB_OSABI_QNXNTO,
-
   GDB_OSABI_CYGWIN,
   GDB_OSABI_AIX,
   GDB_OSABI_DICOS,
   GDB_OSABI_DARWIN,
+  GDB_OSABI_SYMBIAN,
 
   GDB_OSABI_INVALID		/* keep this last */
 };

Re: Add arm-symbianelf support.

[Daniel Jacobowitz]

On Thu, Feb 25, 2010 at 08:06:50PM +0000, Pedro Alves wrote:
> This patch of Daniel's adds basic support for arm-symbianelf
> to gdb.
> 
> Daniel, do you think the arm_symbian_osabi_sniffer is
> still sufficiently tight to not cause problems in
> --enable-target=all builds?  Otherwise, this looks
> good to me.  :-)

Yes, I think this is still safe.  It's not obvious from the commands,
but the key is ET_DYN with the program headers not mapped; ET_EXEC
without mapped headers is common (bare metal applications are usually
like this).

I wish there were a better marker.  Maybe there is nowadays?

-- 
Daniel Jacobowitz
CodeSourcery

Re: Add arm-symbianelf support.

[Pedro Alves]

On Thursday 25 February 2010 20:10:15, Daniel Jacobowitz wrote:
> On Thu, Feb 25, 2010 at 08:06:50PM +0000, Pedro Alves wrote:
> > This patch of Daniel's adds basic support for arm-symbianelf
> > to gdb.
> > 
> > Daniel, do you think the arm_symbian_osabi_sniffer is
> > still sufficiently tight to not cause problems in
> > --enable-target=all builds?  Otherwise, this looks
> > good to me.  :-)
> 
> Yes, I think this is still safe.  It's not obvious from the commands,
> but the key is ET_DYN with the program headers not mapped; ET_EXEC
> without mapped headers is common (bare metal applications are usually
> like this).

Thanks.  I've applied the patch then.

> I wish there were a better marker.  Maybe there is nowadays?

I don't see one, but I'll keep an eye out for it.

-- 
Pedro Alves

Re: Add arm-symbianelf support.

[Eli Zaretskii]

> From: Pedro Alves <pedro@codesourcery.com>
> Date: Thu, 25 Feb 2010 20:06:50 +0000
> 
> This patch of Daniel's adds basic support for arm-symbianelf
> to gdb.

Does this warrant a NEWS entry?

Re: Add arm-symbianelf support.

[Pedro Alves]

On Thursday 25 February 2010 20:06:50, Pedro Alves wrote:
> This patch of Daniel's adds basic support for arm-symbianelf
> to gdb.

(...)

> A short NEWS blurb is missing; I'll handle that next.

Here is is.  Okay?

-- 
Pedro Alves

2010-02-26  Pedro Alves  <pedro@codesourcery.com>

	gdb/
	* NEWS: Add "New targets" section, and mention ARM Symbian
	support.

---
 gdb/NEWS |    4 ++++
 1 file changed, 4 insertions(+)

Index: src/gdb/NEWS
===================================================================
--- src.orig/gdb/NEWS	2010-02-26 14:40:54.000000000 +0000
+++ src/gdb/NEWS	2010-02-26 14:44:09.000000000 +0000
@@ -8,6 +8,10 @@
 The GDB Python API now has access to symbols, symbol tables, and
 frame's code blocks.
 
+* New targets
+
+ARM Symbian			arm*-*-symbianelf*
+
 *** Changes in GDB 7.1
 
 * C++ Improvements

Re: Add arm-symbianelf support.

[Eli Zaretskii]

> From: Pedro Alves <pedro@codesourcery.com>
> Date: Fri, 26 Feb 2010 14:49:48 +0000
> 
> On Thursday 25 February 2010 20:06:50, Pedro Alves wrote:
> > This patch of Daniel's adds basic support for arm-symbianelf
> > to gdb.
> 
> (...)
> 
> > A short NEWS blurb is missing; I'll handle that next.
> 
> Here is is.  Okay?

Yes, thanks.