Message-ID: <548343C8.1020109@gmail.com>

  Date: Sun, 07 Dec 2014 01:58:32 +0800

  From: Wei-cheng Wang <cole945 at gmail dot com>

  To: uweigand at de dot ibm dot com, gdb-patches at sourceware dot org

  Subject: Re: [PATCH 1/3 v2] Process record support for PowerPC

  2014-12-06  Wei-cheng Wang  <cole945@gmail.com>

	      * rs6000-tdep.c (rs6000_in_function_epilogue_p): Rename to

	      rs6000_in_function_epilogue_frame_p and add an argument

	      for frame_info.

	      (rs6000_epilogue_frame_cache, rs6000_epilogue_frame_this_id,

	      rs6000_epilogue_frame_prev_register, rs6000_epilogue_frame_sniffer):

	      New functions.

	      (rs6000_epilogue_frame_unwind): New.

	      (rs6000_gdbarch_init): Append epilogue unwinder.

commit 2608dbf8a3ee666ac0a7d5d7c45611d489edcda5

Author: Wei-cheng Wang <cole945@gmail.com>

Date:   Sat Jan 17 14:29:16 2015 +0800

    Epilogue unwinder for PowerPC.

Index: gdb-7.6.1/gdb/rs6000-tdep.c

===================================================================

--- gdb-7.6.1.orig/gdb/rs6000-tdep.c

+++ gdb-7.6.1/gdb/rs6000-tdep.c

@@ -873,14 +873,14 @@ insn_changes_sp_or_jumps (unsigned long

            limit for the size of an epilogue.  */

 static int

-rs6000_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)

+rs6000_in_function_epilogue_frame_p (struct frame_info *curfrm,

+				     struct gdbarch *gdbarch, CORE_ADDR pc)

 {

   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);

   bfd_byte insn_buf[PPC_INSN_SIZE];

   CORE_ADDR scan_pc, func_start, func_end, epilogue_start, epilogue_end;

   unsigned long insn;

-  struct frame_info *curfrm;

   /* Find the search limits based on function boundaries and hard limit.  */

@@ -893,8 +893,6 @@ rs6000_in_function_epilogue_p (struct gd

   epilogue_end = pc + PPC_MAX_EPILOGUE_INSTRUCTIONS * PPC_INSN_SIZE;

   if (epilogue_end > func_end) epilogue_end = func_end;

-  curfrm = get_current_frame ();

-

   /* Scan forward until next 'blr'.  */

   for (scan_pc = pc; scan_pc < epilogue_end; scan_pc += PPC_INSN_SIZE)

@@ -935,6 +933,15 @@ rs6000_in_function_epilogue_p (struct gd

   return 0;

 }

+/* Implementation of gdbarch_in_function_epilogue_p.  */

+

+static int

+rs6000_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)

+{

+  return rs6000_in_function_epilogue_frame_p (get_current_frame (),

+					      gdbarch, pc);

+}

+

 /* Get the ith function argument for the current function.  */

 static CORE_ADDR

 rs6000_fetch_pointer_argument (struct frame_info *frame, int argi, 

@@ -3388,6 +3395,89 @@ static const struct frame_unwind rs6000_

   NULL,

   default_frame_sniffer

 };

+

+static struct rs6000_frame_cache *

+rs6000_epilogue_frame_cache (struct frame_info *this_frame, void **this_cache)

+{

+  volatile struct gdb_exception ex;

+  struct rs6000_frame_cache *cache;

+  struct gdbarch *gdbarch = get_frame_arch (this_frame);

+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

+  CORE_ADDR sp;

+

+  if (*this_cache)

+    return *this_cache;

+

+  cache = FRAME_OBSTACK_ZALLOC (struct rs6000_frame_cache);

+  (*this_cache) = cache;

+  cache->saved_regs = trad_frame_alloc_saved_regs (this_frame);

+

+  TRY_CATCH (ex, RETURN_MASK_ERROR)

+    {

+      /* At this point the stack looks as if we just entered the

+	 function, and the return address is stored in LR.  */

+      CORE_ADDR sp, lr;

+

+      sp = get_frame_register_unsigned (this_frame, gdbarch_sp_regnum (gdbarch));

+      lr = get_frame_register_unsigned (this_frame, tdep->ppc_lr_regnum);

+

+      cache->base = sp;

+      cache->initial_sp = sp;

+

+      trad_frame_set_value (cache->saved_regs,

+			    gdbarch_pc_regnum (gdbarch), lr);

+    }

+  if (ex.reason < 0 && ex.error != NOT_AVAILABLE_ERROR)

+    throw_exception (ex);

+

+  return cache;

+}

+

+static void

+rs6000_epilogue_frame_this_id (struct frame_info *this_frame,

+			       void **this_cache, struct frame_id *this_id)

+{

+  CORE_ADDR pc;

+  struct rs6000_frame_cache *info =

+    rs6000_epilogue_frame_cache (this_frame, this_cache);

+

+  pc = get_frame_func (this_frame);

+  if (info->base == 0)

+    (*this_id) = frame_id_build_unavailable_stack (pc);

+  else

+    (*this_id) = frame_id_build (info->base, pc);

+}

+

+static struct value *

+rs6000_epilogue_frame_prev_register (struct frame_info *this_frame,

+				     void **this_cache, int regnum)

+{

+  struct rs6000_frame_cache *info =

+    rs6000_epilogue_frame_cache (this_frame, this_cache);

+  return trad_frame_get_prev_register (this_frame, info->saved_regs, regnum);

+}

+

+static int

+rs6000_epilogue_frame_sniffer (const struct frame_unwind *self,

+			       struct frame_info *this_frame,

+			       void **this_prologue_cache)

+{

+  if (frame_relative_level (this_frame) == 0)

+    return rs6000_in_function_epilogue_frame_p (this_frame,

+						get_frame_arch (this_frame),

+						get_frame_pc (this_frame));

+  else

+    return 0;

+}

+

+static const struct frame_unwind rs6000_epilogue_frame_unwind =

+{

+  NORMAL_FRAME,

+  default_frame_unwind_stop_reason,

+  rs6000_epilogue_frame_this_id, rs6000_epilogue_frame_prev_register,

+  NULL,

+  rs6000_epilogue_frame_sniffer

+};

 static CORE_ADDR

@@ -4207,6 +4297,7 @@ rs6000_gdbarch_init (struct gdbarch_info

     case GDB_OSABI_NETBSD_ELF:

     case GDB_OSABI_UNKNOWN:

       set_gdbarch_unwind_pc (gdbarch, rs6000_unwind_pc);

+      frame_unwind_append_unwinder (gdbarch, &rs6000_epilogue_frame_unwind);

       frame_unwind_append_unwinder (gdbarch, &rs6000_frame_unwind);

       set_gdbarch_dummy_id (gdbarch, rs6000_dummy_id);

       frame_base_append_sniffer (gdbarch, rs6000_frame_base_sniffer);

@@ -4215,6 +4306,7 @@ rs6000_gdbarch_init (struct gdbarch_info

       set_gdbarch_believe_pcc_promotion (gdbarch, 1);

       set_gdbarch_unwind_pc (gdbarch, rs6000_unwind_pc);

+      frame_unwind_append_unwinder (gdbarch, &rs6000_epilogue_frame_unwind);

       frame_unwind_append_unwinder (gdbarch, &rs6000_frame_unwind);

       set_gdbarch_dummy_id (gdbarch, rs6000_dummy_id);

       frame_base_append_sniffer (gdbarch, rs6000_frame_base_sniffer);