2004-10-30 Andrew Cagney <cagney@gnu.org>

	* config/mips/embed.mt (TDEPFILES): Add mips-mdebug-tdep.o.
	* mips-mdebug-tdep.h, mips-mdebug-tdep.c: New files.
	* mips-tdep.c (mips_mdebug_frame_cache)
	(mips_mdebug_frame_this_id, mips_mdebug_frame_prev_register)
	(mips_mdebug_frame_unwind, mips_mdebug_frame_sniffer)
	(mips_mdebug_frame_base_address, mips_mdebug_frame_sniffer)
	(mips_mdebug_frame_base_sniffer, non_heuristic_proc_desc)
	(compare_pdr_entries, the_bfd, mips16_fetch_instruction): Delete.
	(mips_gdbarch_init): Do not append mdebug sniffers.
	(PROC_LOW_ADDR, PROC_HIGH_ADDR, PROC_FRAME_OFFSET)
	(PROC_FRAME_REG, PROC_FRAME_ADJUST, PROC_REG_MASK)
	(PROC_FREG_MASK, PROC_REG_OFFSET, PROC_FREG_OFFSET, PROC_PC_REG)
	(PROC_SYMBOL, _PROC_MAGIC_): Delete.
	* Makefile.in: Update dependencies.

1 files changed, 493 insertions, 0 deletions

diff --git a/gdb/mips-mdebug-tdep.c b/gdb/mips-mdebug-tdep.c
new file mode 100644
index 0000000..efb105d
--- /dev/null
+++ b/gdb/mips-mdebug-tdep.c
@@ -0,0 +1,493 @@
+/* Target-dependent code for the MDEBUG MIPS architecture, for GDB,
+   the GNU Debugger.
+
+   Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
+   1997, 1998, 1999, 2000, 2001, 2002, 2003, 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.  */
+
+#include "defs.h"
+#include "frame.h"
+#include "mips-tdep.h"
+#include "trad-frame.h"
+#include "block.h"
+#include "symtab.h"
+#include "objfiles.h"
+#include "elf/mips.h"
+#include "elf-bfd.h"
+#include "gdb_assert.h"
+#include "frame-unwind.h"
+#include "frame-base.h"
+#include "mips-mdebug-tdep.h"
+
+#define PROC_LOW_ADDR(proc) ((proc)->pdr.adr)	/* least address */
+#define PROC_HIGH_ADDR(proc) ((proc)->high_addr)	/* upper address bound */
+#define PROC_FRAME_OFFSET(proc) ((proc)->pdr.frameoffset)
+#define PROC_FRAME_REG(proc) ((proc)->pdr.framereg)
+#define PROC_FRAME_ADJUST(proc)  ((proc)->frame_adjust)
+#define PROC_REG_MASK(proc) ((proc)->pdr.regmask)
+#define PROC_FREG_MASK(proc) ((proc)->pdr.fregmask)
+#define PROC_REG_OFFSET(proc) ((proc)->pdr.regoffset)
+#define PROC_FREG_OFFSET(proc) ((proc)->pdr.fregoffset)
+#define PROC_PC_REG(proc) ((proc)->pdr.pcreg)
+/* FIXME drow/2002-06-10: If a pointer on the host is bigger than a long,
+   this will corrupt pdr.iline.  Fortunately we don't use it.  */
+#define PROC_SYMBOL(proc) (*(struct symbol**)&(proc)->pdr.isym)
+#define _PROC_MAGIC_ 0x0F0F0F0F
+
+struct mips_objfile_private
+{
+  bfd_size_type size;
+  char *contents;
+};
+
+/* Global used to communicate between non_heuristic_proc_desc and
+   compare_pdr_entries within qsort ().  */
+static bfd *the_bfd;
+
+static int
+compare_pdr_entries (const void *a, const void *b)
+{
+  CORE_ADDR lhs = bfd_get_32 (the_bfd, (bfd_byte *) a);
+  CORE_ADDR rhs = bfd_get_32 (the_bfd, (bfd_byte *) b);
+
+  if (lhs < rhs)
+    return -1;
+  else if (lhs == rhs)
+    return 0;
+  else
+    return 1;
+}
+
+static const struct objfile_data *mips_pdr_data;
+
+static mips_extra_func_info_t
+non_heuristic_proc_desc (CORE_ADDR pc, CORE_ADDR *addrptr)
+{
+  CORE_ADDR startaddr;
+  mips_extra_func_info_t proc_desc;
+  struct block *b = block_for_pc (pc);
+  struct symbol *sym;
+  struct obj_section *sec;
+  struct mips_objfile_private *priv;
+
+  find_pc_partial_function (pc, NULL, &startaddr, NULL);
+  if (addrptr)
+    *addrptr = startaddr;
+
+  priv = NULL;
+
+  sec = find_pc_section (pc);
+  if (sec != NULL)
+    {
+      priv = (struct mips_objfile_private *) objfile_data (sec->objfile, mips_pdr_data);
+
+      /* Search the ".pdr" section generated by GAS.  This includes most of
+         the information normally found in ECOFF PDRs.  */
+
+      the_bfd = sec->objfile->obfd;
+      if (priv == NULL
+	  && (the_bfd->format == bfd_object
+	      && bfd_get_flavour (the_bfd) == bfd_target_elf_flavour
+	      && elf_elfheader (the_bfd)->e_ident[EI_CLASS] == ELFCLASS64))
+	{
+	  /* Right now GAS only outputs the address as a four-byte sequence.
+	     This means that we should not bother with this method on 64-bit
+	     targets (until that is fixed).  */
+
+	  priv = obstack_alloc (&sec->objfile->objfile_obstack,
+				sizeof (struct mips_objfile_private));
+	  priv->size = 0;
+	  set_objfile_data (sec->objfile, mips_pdr_data, priv);
+	}
+      else if (priv == NULL)
+	{
+	  asection *bfdsec;
+
+	  priv = obstack_alloc (&sec->objfile->objfile_obstack,
+				sizeof (struct mips_objfile_private));
+
+	  bfdsec = bfd_get_section_by_name (sec->objfile->obfd, ".pdr");
+	  if (bfdsec != NULL)
+	    {
+	      priv->size = bfd_section_size (sec->objfile->obfd, bfdsec);
+	      priv->contents = obstack_alloc (&sec->objfile->objfile_obstack,
+					      priv->size);
+	      bfd_get_section_contents (sec->objfile->obfd, bfdsec,
+					priv->contents, 0, priv->size);
+
+	      /* In general, the .pdr section is sorted.  However, in the
+	         presence of multiple code sections (and other corner cases)
+	         it can become unsorted.  Sort it so that we can use a faster
+	         binary search.  */
+	      qsort (priv->contents, priv->size / 32, 32,
+		     compare_pdr_entries);
+	    }
+	  else
+	    priv->size = 0;
+
+	  set_objfile_data (sec->objfile, mips_pdr_data, priv);
+	}
+      the_bfd = NULL;
+
+      if (priv->size != 0)
+	{
+	  int low, mid, high;
+	  char *ptr;
+	  CORE_ADDR pdr_pc;
+
+	  low = 0;
+	  high = priv->size / 32;
+
+	  /* We've found a .pdr section describing this objfile.  We want to
+	     find the entry which describes this code address.  The .pdr
+	     information is not very descriptive; we have only a function
+	     start address.  We have to look for the closest entry, because
+	     the local symbol at the beginning of this function may have
+	     been stripped - so if we ask the symbol table for the start
+	     address we may get a preceding global function.  */
+
+	  /* First, find the last .pdr entry starting at or before PC.  */
+	  do
+	    {
+	      mid = (low + high) / 2;
+
+	      ptr = priv->contents + mid * 32;
+	      pdr_pc = bfd_get_signed_32 (sec->objfile->obfd, ptr);
+	      pdr_pc += ANOFFSET (sec->objfile->section_offsets,
+				  SECT_OFF_TEXT (sec->objfile));
+
+	      if (pdr_pc > pc)
+		high = mid;
+	      else
+		low = mid + 1;
+	    }
+	  while (low != high);
+
+	  /* Both low and high point one past the PDR of interest.  If
+	     both are zero, that means this PC is before any region
+	     covered by a PDR, i.e. pdr_pc for the first PDR entry is
+	     greater than PC.  */
+	  if (low > 0)
+	    {
+	      ptr = priv->contents + (low - 1) * 32;
+	      pdr_pc = bfd_get_signed_32 (sec->objfile->obfd, ptr);
+	      pdr_pc += ANOFFSET (sec->objfile->section_offsets,
+				  SECT_OFF_TEXT (sec->objfile));
+	    }
+
+	  /* We don't have a range, so we have no way to know for sure
+	     whether we're in the correct PDR or a PDR for a preceding
+	     function and the current function was a stripped local
+	     symbol.  But if the PDR's PC is at least as great as the
+	     best guess from the symbol table, assume that it does cover
+	     the right area; if a .pdr section is present at all then
+	     nearly every function will have an entry.  The biggest exception
+	     will be the dynamic linker stubs; conveniently these are
+	     placed before .text instead of after.  */
+
+	  if (pc >= pdr_pc && pdr_pc >= startaddr)
+	    {
+	      struct symbol *sym = find_pc_function (pc);
+
+	      if (addrptr)
+		*addrptr = pdr_pc;
+
+	      /* Fill in what we need of the proc_desc.  */
+	      proc_desc = (mips_extra_func_info_t)
+		obstack_alloc (&sec->objfile->objfile_obstack,
+			       sizeof (struct mips_extra_func_info));
+	      PROC_LOW_ADDR (proc_desc) = pdr_pc;
+
+	      /* Only used for dummy frames.  */
+	      PROC_HIGH_ADDR (proc_desc) = 0;
+
+	      PROC_FRAME_OFFSET (proc_desc)
+		= bfd_get_32 (sec->objfile->obfd, ptr + 20);
+	      PROC_FRAME_REG (proc_desc) = bfd_get_32 (sec->objfile->obfd,
+						       ptr + 24);
+	      PROC_FRAME_ADJUST (proc_desc) = 0;
+	      PROC_REG_MASK (proc_desc) = bfd_get_32 (sec->objfile->obfd,
+						      ptr + 4);
+	      PROC_FREG_MASK (proc_desc) = bfd_get_32 (sec->objfile->obfd,
+						       ptr + 12);
+	      PROC_REG_OFFSET (proc_desc) = bfd_get_32 (sec->objfile->obfd,
+							ptr + 8);
+	      PROC_FREG_OFFSET (proc_desc)
+		= bfd_get_32 (sec->objfile->obfd, ptr + 16);
+	      PROC_PC_REG (proc_desc) = bfd_get_32 (sec->objfile->obfd,
+						    ptr + 28);
+	      proc_desc->pdr.isym = (long) sym;
+
+	      return proc_desc;
+	    }
+	}
+    }
+
+  if (b == NULL)
+    return NULL;
+
+  if (startaddr > BLOCK_START (b))
+    {
+      /* This is the "pathological" case referred to in a comment in
+         print_frame_info.  It might be better to move this check into
+         symbol reading.  */
+      return NULL;
+    }
+
+  sym = lookup_symbol (MIPS_EFI_SYMBOL_NAME, b, LABEL_DOMAIN, 0, NULL);
+
+  /* If we never found a PDR for this function in symbol reading, then
+     examine prologues to find the information.  */
+  if (sym)
+    {
+      proc_desc = (mips_extra_func_info_t) SYMBOL_VALUE (sym);
+      if (PROC_FRAME_REG (proc_desc) == -1)
+	return NULL;
+      else
+	return proc_desc;
+    }
+  else
+    return NULL;
+}
+
+struct mips_frame_cache
+{
+  CORE_ADDR base;
+  struct trad_frame_saved_reg *saved_regs;
+};
+
+static struct mips_frame_cache *
+mips_mdebug_frame_cache (struct frame_info *next_frame, void **this_cache)
+{
+  CORE_ADDR startaddr = 0;
+  mips_extra_func_info_t proc_desc;
+  struct mips_frame_cache *cache;
+  struct gdbarch *gdbarch = get_frame_arch (next_frame);
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+  /* r0 bit means kernel trap */
+  int kernel_trap;
+  /* What registers have been saved?  Bitmasks.  */
+  unsigned long gen_mask, float_mask;
+
+  if ((*this_cache) != NULL)
+    return (*this_cache);
+  cache = FRAME_OBSTACK_ZALLOC (struct mips_frame_cache);
+  (*this_cache) = cache;
+  cache->saved_regs = trad_frame_alloc_saved_regs (next_frame);
+
+  /* Get the mdebug proc descriptor.  */
+  proc_desc = non_heuristic_proc_desc (frame_pc_unwind (next_frame),
+				       &startaddr);
+  /* Must be true.  This is only called when the sniffer detected a
+     proc descriptor.  */
+  gdb_assert (proc_desc != NULL);
+
+  /* Extract the frame's base.  */
+  cache->base = (frame_unwind_register_signed (next_frame, NUM_REGS + PROC_FRAME_REG (proc_desc))
+		 + PROC_FRAME_OFFSET (proc_desc) - PROC_FRAME_ADJUST (proc_desc));
+
+  kernel_trap = PROC_REG_MASK (proc_desc) & 1;
+  gen_mask = kernel_trap ? 0xFFFFFFFF : PROC_REG_MASK (proc_desc);
+  float_mask = kernel_trap ? 0xFFFFFFFF : PROC_FREG_MASK (proc_desc);
+  
+  /* Must be true.  The in_prologue case is left for the heuristic
+     unwinder.  This is always used on kernel traps.  */
+  gdb_assert (!in_prologue (frame_pc_unwind (next_frame), PROC_LOW_ADDR (proc_desc))
+	      || kernel_trap);
+
+  /* Fill in the offsets for the registers which gen_mask says were
+     saved.  */
+  {
+    CORE_ADDR reg_position = (cache->base + PROC_REG_OFFSET (proc_desc));
+    int ireg;
+
+    for (ireg = MIPS_NUMREGS - 1; gen_mask; --ireg, gen_mask <<= 1)
+      if (gen_mask & 0x80000000)
+	{
+	  cache->saved_regs[NUM_REGS + ireg].addr = reg_position;
+	  reg_position -= mips_abi_regsize (gdbarch);
+	}
+  }
+
+  /* Fill in the offsets for the registers which float_mask says were
+     saved.  */
+  {
+    CORE_ADDR reg_position = (cache->base
+			      + PROC_FREG_OFFSET (proc_desc));
+    int ireg;
+    /* Fill in the offsets for the float registers which float_mask
+       says were saved.  */
+    for (ireg = MIPS_NUMREGS - 1; float_mask; --ireg, float_mask <<= 1)
+      if (float_mask & 0x80000000)
+	{
+	  if (mips_abi_regsize (gdbarch) == 4
+	      && TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
+	    {
+	      /* On a big endian 32 bit ABI, floating point registers
+	         are paired to form doubles such that the most
+	         significant part is in $f[N+1] and the least
+	         significant in $f[N] vis: $f[N+1] ||| $f[N].  The
+	         registers are also spilled as a pair and stored as a
+	         double.
+
+	         When little-endian the least significant part is
+	         stored first leading to the memory order $f[N] and
+	         then $f[N+1].
+
+	         Unfortunately, when big-endian the most significant
+	         part of the double is stored first, and the least
+	         significant is stored second.  This leads to the
+	         registers being ordered in memory as firt $f[N+1] and
+	         then $f[N].
+
+	         For the big-endian case make certain that the
+	         addresses point at the correct (swapped) locations
+	         $f[N] and $f[N+1] pair (keep in mind that
+	         reg_position is decremented each time through the
+	         loop).  */
+	      if ((ireg & 1))
+		cache->saved_regs[NUM_REGS + mips_regnum (current_gdbarch)->fp0 + ireg]
+		  .addr = reg_position - mips_abi_regsize (gdbarch);
+	      else
+		cache->saved_regs[NUM_REGS + mips_regnum (current_gdbarch)->fp0 + ireg]
+		  .addr = reg_position + mips_abi_regsize (gdbarch);
+	    }
+	  else
+	    cache->saved_regs[NUM_REGS + mips_regnum (current_gdbarch)->fp0 + ireg]
+	      .addr = reg_position;
+	  reg_position -= mips_abi_regsize (gdbarch);
+	}
+
+    cache->saved_regs[NUM_REGS + mips_regnum (current_gdbarch)->pc]
+      = cache->saved_regs[NUM_REGS + MIPS_RA_REGNUM];
+  }
+
+  /* SP_REGNUM, contains the value and not the address.  */
+  trad_frame_set_value (cache->saved_regs, NUM_REGS + MIPS_SP_REGNUM, cache->base);
+
+  return (*this_cache);
+}
+
+static void
+mips_mdebug_frame_this_id (struct frame_info *next_frame, void **this_cache,
+			   struct frame_id *this_id)
+{
+  struct mips_frame_cache *info = mips_mdebug_frame_cache (next_frame,
+							   this_cache);
+  (*this_id) = frame_id_build (info->base, frame_func_unwind (next_frame));
+}
+
+static void
+mips_mdebug_frame_prev_register (struct frame_info *next_frame,
+				 void **this_cache,
+				 int regnum, int *optimizedp,
+				 enum lval_type *lvalp, CORE_ADDR *addrp,
+				 int *realnump, void *valuep)
+{
+  struct mips_frame_cache *info = mips_mdebug_frame_cache (next_frame,
+							   this_cache);
+  trad_frame_get_prev_register (next_frame, info->saved_regs, regnum,
+				optimizedp, lvalp, addrp, realnump, valuep);
+}
+
+static const struct frame_unwind mips_mdebug_frame_unwind =
+{
+  NORMAL_FRAME,
+  mips_mdebug_frame_this_id,
+  mips_mdebug_frame_prev_register
+};
+
+static const struct frame_unwind *
+mips_mdebug_frame_sniffer (struct frame_info *next_frame)
+{
+  CORE_ADDR pc = frame_pc_unwind (next_frame);
+  CORE_ADDR startaddr = 0;
+  mips_extra_func_info_t proc_desc;
+  int kernel_trap;
+
+  /* Don't use this on MIPS16.  */
+  if (mips_pc_is_mips16 (pc))
+    return NULL;
+
+  /* Only use the mdebug frame unwinder on mdebug frames where all the
+     registers have been saved.  Leave hard cases such as no mdebug or
+     in prologue for the heuristic unwinders.  */
+
+  proc_desc = non_heuristic_proc_desc (pc, &startaddr);
+  if (proc_desc == NULL)
+    return NULL;
+
+  /* Not sure exactly what kernel_trap means, but if it means the
+     kernel saves the registers without a prologue doing it, we better
+     not examine the prologue to see whether registers have been saved
+     yet.  */
+  kernel_trap = PROC_REG_MASK (proc_desc) & 1;
+  if (kernel_trap)
+    return &mips_mdebug_frame_unwind;
+
+  /* In any frame other than the innermost or a frame interrupted by a
+     signal, we assume that all registers have been saved.  This
+     assumes that all register saves in a function happen before the
+     first function call.  */
+  if (!in_prologue (pc, PROC_LOW_ADDR (proc_desc)))
+    return &mips_mdebug_frame_unwind;
+
+  return NULL;
+}
+
+static CORE_ADDR
+mips_mdebug_frame_base_address (struct frame_info *next_frame,
+				void **this_cache)
+{
+  struct mips_frame_cache *info = mips_mdebug_frame_cache (next_frame,
+							   this_cache);
+  return info->base;
+}
+
+static const struct frame_base mips_mdebug_frame_base = {
+  &mips_mdebug_frame_unwind,
+  mips_mdebug_frame_base_address,
+  mips_mdebug_frame_base_address,
+  mips_mdebug_frame_base_address
+};
+
+static const struct frame_base *
+mips_mdebug_frame_base_sniffer (struct frame_info *next_frame)
+{
+  if (mips_mdebug_frame_sniffer (next_frame) != NULL)
+    return &mips_mdebug_frame_base;
+  else
+    return NULL;
+}
+
+void
+mips_mdebug_append_sniffers (struct gdbarch *gdbarch)
+{
+  frame_unwind_append_sniffer (gdbarch, mips_mdebug_frame_sniffer);
+  frame_base_append_sniffer (gdbarch, mips_mdebug_frame_base_sniffer);
+}
+
+
+extern void _initialize_mips_mdebug_tdep (void);
+void
+_initialize_mips_mdebug_tdep (void)
+{
+  mips_pdr_data = register_objfile_data ();
+}