Initial creation of sourceware repositorygdb-4_18-branchpoint

1 files changed, 1349 insertions, 0 deletions

diff --git a/gdb/irix5-nat.c b/gdb/irix5-nat.c
new file mode 100644
index 0000000..b3373a9
--- /dev/null
+++ b/gdb/irix5-nat.c
@@ -0,0 +1,1349 @@
+/* Native support for the SGI Iris running IRIX version 5, for GDB.
+   Copyright 1988, 89, 90, 91, 92, 93, 94, 95, 96, 98, 1999
+   Free Software Foundation, Inc.
+   Contributed by Alessandro Forin(af@cs.cmu.edu) at CMU
+   and by Per Bothner(bothner@cs.wisc.edu) at U.Wisconsin.
+   Implemented for Irix 4.x by Garrett A. Wollman.
+   Modified for Irix 5.x by Ian Lance Taylor.
+
+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 "inferior.h"
+#include "gdbcore.h"
+#include "target.h"
+
+#include "gdb_string.h"
+#include <sys/time.h>
+#include <sys/procfs.h>
+#include <setjmp.h>		/* For JB_XXX.  */
+
+static void
+fetch_core_registers PARAMS ((char *, unsigned int, int, CORE_ADDR));
+
+/* Size of elements in jmpbuf */
+
+#define JB_ELEMENT_SIZE 4
+
+/*
+ * See the comment in m68k-tdep.c regarding the utility of these functions.
+ *
+ * These definitions are from the MIPS SVR4 ABI, so they may work for
+ * any MIPS SVR4 target.
+ */
+
+void 
+supply_gregset (gregsetp)
+     gregset_t *gregsetp;
+{
+  register int regi;
+  register greg_t *regp = &(*gregsetp)[0];
+  int gregoff = sizeof (greg_t) - MIPS_REGSIZE;
+  static char zerobuf[MAX_REGISTER_RAW_SIZE] = {0};
+
+  for(regi = 0; regi <= CTX_RA; regi++)
+    supply_register (regi, (char *)(regp + regi) + gregoff);
+
+  supply_register (PC_REGNUM, (char *)(regp + CTX_EPC) + gregoff);
+  supply_register (HI_REGNUM, (char *)(regp + CTX_MDHI) + gregoff);
+  supply_register (LO_REGNUM, (char *)(regp + CTX_MDLO) + gregoff);
+  supply_register (CAUSE_REGNUM, (char *)(regp + CTX_CAUSE) + gregoff);
+
+  /* Fill inaccessible registers with zero.  */
+  supply_register (BADVADDR_REGNUM, zerobuf);
+}
+
+void
+fill_gregset (gregsetp, regno)
+     gregset_t *gregsetp;
+     int regno;
+{
+  int regi;
+  register greg_t *regp = &(*gregsetp)[0];
+
+  /* Under Irix6, if GDB is built with N32 ABI and is debugging an O32
+     executable, we have to sign extend the registers to 64 bits before
+     filling in the gregset structure.  */
+
+  for (regi = 0; regi <= CTX_RA; regi++)
+    if ((regno == -1) || (regno == regi))
+      *(regp + regi) =
+	extract_signed_integer (&registers[REGISTER_BYTE (regi)],
+				REGISTER_RAW_SIZE (regi));
+
+  if ((regno == -1) || (regno == PC_REGNUM))
+    *(regp + CTX_EPC) =
+      extract_signed_integer (&registers[REGISTER_BYTE (PC_REGNUM)],
+			      REGISTER_RAW_SIZE (PC_REGNUM));
+
+  if ((regno == -1) || (regno == CAUSE_REGNUM))
+    *(regp + CTX_CAUSE) =
+      extract_signed_integer (&registers[REGISTER_BYTE (CAUSE_REGNUM)],
+			      REGISTER_RAW_SIZE (CAUSE_REGNUM));
+
+  if ((regno == -1) || (regno == HI_REGNUM))
+    *(regp + CTX_MDHI) =
+      extract_signed_integer (&registers[REGISTER_BYTE (HI_REGNUM)],
+			      REGISTER_RAW_SIZE (HI_REGNUM));
+
+  if ((regno == -1) || (regno == LO_REGNUM))
+    *(regp + CTX_MDLO) =
+      extract_signed_integer (&registers[REGISTER_BYTE (LO_REGNUM)],
+			      REGISTER_RAW_SIZE (LO_REGNUM));
+}
+
+/*
+ * Now we do the same thing for floating-point registers.
+ * We don't bother to condition on FP0_REGNUM since any
+ * reasonable MIPS configuration has an R3010 in it.
+ *
+ * Again, see the comments in m68k-tdep.c.
+ */
+
+void
+supply_fpregset (fpregsetp)
+     fpregset_t *fpregsetp;
+{
+  register int regi;
+  static char zerobuf[MAX_REGISTER_RAW_SIZE] = {0};
+
+  /* FIXME, this is wrong for the N32 ABI which has 64 bit FP regs. */
+
+  for (regi = 0; regi < 32; regi++)
+    supply_register (FP0_REGNUM + regi,
+		     (char *)&fpregsetp->fp_r.fp_regs[regi]);
+
+  supply_register (FCRCS_REGNUM, (char *)&fpregsetp->fp_csr);
+
+  /* FIXME: how can we supply FCRIR_REGNUM?  SGI doesn't tell us. */
+  supply_register (FCRIR_REGNUM, zerobuf);
+}
+
+void
+fill_fpregset (fpregsetp, regno)
+     fpregset_t *fpregsetp;
+     int regno;
+{
+  int regi;
+  char *from, *to;
+
+  /* FIXME, this is wrong for the N32 ABI which has 64 bit FP regs. */
+
+  for (regi = FP0_REGNUM; regi < FP0_REGNUM + 32; regi++)
+    {
+      if ((regno == -1) || (regno == regi))
+	{
+	  from = (char *) &registers[REGISTER_BYTE (regi)];
+	  to = (char *) &(fpregsetp->fp_r.fp_regs[regi - FP0_REGNUM]);
+	  memcpy(to, from, REGISTER_RAW_SIZE (regi));
+	}
+    }
+
+  if ((regno == -1) || (regno == FCRCS_REGNUM))
+    fpregsetp->fp_csr = *(unsigned *) &registers[REGISTER_BYTE(FCRCS_REGNUM)];
+}
+
+
+/* Figure out where the longjmp will land.
+   We expect the first arg to be a pointer to the jmp_buf structure from which
+   we extract the pc (JB_PC) that we will land at.  The pc is copied into PC.
+   This routine returns true on success. */
+
+int
+get_longjmp_target (pc)
+     CORE_ADDR *pc;
+{
+  char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT];
+  CORE_ADDR jb_addr;
+
+  jb_addr = read_register (A0_REGNUM);
+
+  if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf,
+			  TARGET_PTR_BIT / TARGET_CHAR_BIT))
+    return 0;
+
+  *pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
+
+  return 1;
+}
+
+static void
+fetch_core_registers (core_reg_sect, core_reg_size, which, reg_addr)
+     char *core_reg_sect;
+     unsigned core_reg_size;
+     int which;			/* Unused */
+     CORE_ADDR reg_addr;	/* Unused */
+{
+  if (core_reg_size == REGISTER_BYTES)
+    {
+      memcpy ((char *)registers, core_reg_sect, core_reg_size);
+    }
+  else if (MIPS_REGSIZE == 4 &&
+	   core_reg_size == (2 * MIPS_REGSIZE) * NUM_REGS)
+    {
+      /* This is a core file from a N32 executable, 64 bits are saved
+	 for all registers.  */
+      char *srcp = core_reg_sect;
+      char *dstp = registers;
+      int regno;
+
+      for (regno = 0; regno < NUM_REGS; regno++)
+	{
+	  if (regno >= FP0_REGNUM && regno < (FP0_REGNUM + 32))
+	    {
+	      /* FIXME, this is wrong, N32 has 64 bit FP regs, but GDB
+		 currently assumes that they are 32 bit.  */
+	      *dstp++ = *srcp++;
+	      *dstp++ = *srcp++;
+	      *dstp++ = *srcp++;
+	      *dstp++ = *srcp++;
+	      if (REGISTER_RAW_SIZE(regno) == 4)
+		{
+		  /* copying 4 bytes from eight bytes?
+		     I don't see how this can be right...  */
+		  srcp += 4;	
+		}
+	      else
+		{
+		  /* copy all 8 bytes (sizeof(double)) */
+		  *dstp++ = *srcp++;
+		  *dstp++ = *srcp++;
+		  *dstp++ = *srcp++;
+		  *dstp++ = *srcp++;
+		}
+	    }
+	  else
+	    {
+	      srcp += 4;
+	      *dstp++ = *srcp++;
+	      *dstp++ = *srcp++;
+	      *dstp++ = *srcp++;
+	      *dstp++ = *srcp++;
+	    }
+	}
+    }
+  else
+    {
+      warning ("wrong size gregset struct in core file");
+      return;
+    }
+
+  registers_fetched ();
+}
+
+/* Irix 5 uses what appears to be a unique form of shared library
+   support.  This is a copy of solib.c modified for Irix 5.  */
+/* FIXME: Most of this code could be merged with osfsolib.c and solib.c
+   by using next_link_map_member and xfer_link_map_member in solib.c.  */
+
+#include <sys/types.h>
+#include <signal.h>
+#include <sys/param.h>
+#include <fcntl.h>
+
+/* <obj.h> includes <sym.h> and <symconst.h>, which causes conflicts
+   with our versions of those files included by tm-mips.h.  Prevent
+   <obj.h> from including them with some appropriate defines.  */
+#define __SYM_H__
+#define __SYMCONST_H__
+#include <obj.h>
+#ifdef HAVE_OBJLIST_H
+#include <objlist.h>
+#endif
+
+#ifdef NEW_OBJ_INFO_MAGIC
+#define HANDLE_NEW_OBJ_LIST
+#endif
+
+#include "symtab.h"
+#include "bfd.h"
+#include "symfile.h"
+#include "objfiles.h"
+#include "command.h"
+#include "frame.h"
+#include "gnu-regex.h"
+#include "inferior.h"
+#include "language.h"
+#include "gdbcmd.h"
+
+/* The symbol which starts off the list of shared libraries.  */
+#define DEBUG_BASE "__rld_obj_head"
+
+/* Irix 6.x introduces a new variant of object lists.
+   To be able to debug O32 executables under Irix 6, we have to handle both
+   variants.  */
+
+typedef enum
+{
+  OBJ_LIST_OLD,		/* Pre Irix 6.x object list.  */
+  OBJ_LIST_32,		/* 32 Bit Elf32_Obj_Info.  */
+  OBJ_LIST_64		/* 64 Bit Elf64_Obj_Info, FIXME not yet implemented.  */
+} obj_list_variant;
+
+/* Define our own link_map structure.
+   This will help to share code with osfsolib.c and solib.c.  */
+
+struct link_map {
+  obj_list_variant l_variant;	/* which variant of object list */
+  CORE_ADDR l_lladdr;		/* addr in inferior list was read from */
+  CORE_ADDR l_next;		/* address of next object list entry */
+};
+
+/* Irix 5 shared objects are pre-linked to particular addresses
+   although the dynamic linker may have to relocate them if the
+   address ranges of the libraries used by the main program clash.
+   The offset is the difference between the address where the object
+   is mapped and the binding address of the shared library.  */
+#define LM_OFFSET(so) ((so) -> offset)
+/* Loaded address of shared library.  */
+#define LM_ADDR(so) ((so) -> lmstart)
+
+char shadow_contents[BREAKPOINT_MAX];	/* Stash old bkpt addr contents */
+
+struct so_list {
+  struct so_list *next;			/* next structure in linked list */
+  struct link_map lm;
+  CORE_ADDR offset;			/* prelink to load address offset */
+  char *so_name;			/* shared object lib name */
+  CORE_ADDR lmstart;			/* lower addr bound of mapped object */
+  CORE_ADDR lmend;			/* upper addr bound of mapped object */
+  char symbols_loaded;			/* flag: symbols read in yet? */
+  char from_tty;			/* flag: print msgs? */
+  struct objfile *objfile;		/* objfile for loaded lib */
+  struct section_table *sections;
+  struct section_table *sections_end;
+  struct section_table *textsection;
+  bfd *abfd;
+};
+
+static struct so_list *so_list_head;	/* List of known shared objects */
+static CORE_ADDR debug_base;		/* Base of dynamic linker structures */
+static CORE_ADDR breakpoint_addr;	/* Address where end bkpt is set */
+
+/* Local function prototypes */
+
+static void
+sharedlibrary_command PARAMS ((char *, int));
+
+static int
+enable_break PARAMS ((void));
+
+static int
+disable_break PARAMS ((void));
+
+static void
+info_sharedlibrary_command PARAMS ((char *, int));
+
+static int
+symbol_add_stub PARAMS ((char *));
+
+static struct so_list *
+find_solib PARAMS ((struct so_list *));
+
+static struct link_map *
+first_link_map_member PARAMS ((void));
+
+static struct link_map *
+next_link_map_member PARAMS ((struct so_list *));
+
+static void
+xfer_link_map_member PARAMS ((struct so_list *, struct link_map *));
+
+static CORE_ADDR
+locate_base PARAMS ((void));
+
+static int
+solib_map_sections PARAMS ((char *));
+
+/*
+
+LOCAL FUNCTION
+
+	solib_map_sections -- open bfd and build sections for shared lib
+
+SYNOPSIS
+
+	static int solib_map_sections (struct so_list *so)
+
+DESCRIPTION
+
+	Given a pointer to one of the shared objects in our list
+	of mapped objects, use the recorded name to open a bfd
+	descriptor for the object, build a section table, and then
+	relocate all the section addresses by the base address at
+	which the shared object was mapped.
+
+FIXMES
+
+	In most (all?) cases the shared object file name recorded in the
+	dynamic linkage tables will be a fully qualified pathname.  For
+	cases where it isn't, do we really mimic the systems search
+	mechanism correctly in the below code (particularly the tilde
+	expansion stuff?).
+ */
+
+static int
+solib_map_sections (arg)
+     char *arg;
+{
+  struct so_list *so = (struct so_list *) arg;	/* catch_errors bogon */
+  char *filename;
+  char *scratch_pathname;
+  int scratch_chan;
+  struct section_table *p;
+  struct cleanup *old_chain;
+  bfd *abfd;
+  
+  filename = tilde_expand (so -> so_name);
+  old_chain = make_cleanup (free, filename);
+  
+  scratch_chan = openp (getenv ("PATH"), 1, filename, O_RDONLY, 0,
+			&scratch_pathname);
+  if (scratch_chan < 0)
+    {
+      scratch_chan = openp (getenv ("LD_LIBRARY_PATH"), 1, filename,
+			    O_RDONLY, 0, &scratch_pathname);
+    }
+  if (scratch_chan < 0)
+    {
+      perror_with_name (filename);
+    }
+  /* Leave scratch_pathname allocated.  abfd->name will point to it.  */
+
+  abfd = bfd_fdopenr (scratch_pathname, gnutarget, scratch_chan);
+  if (!abfd)
+    {
+      close (scratch_chan);
+      error ("Could not open `%s' as an executable file: %s",
+	     scratch_pathname, bfd_errmsg (bfd_get_error ()));
+    }
+  /* Leave bfd open, core_xfer_memory and "info files" need it.  */
+  so -> abfd = abfd;
+  abfd -> cacheable = true;
+
+  if (!bfd_check_format (abfd, bfd_object))
+    {
+      error ("\"%s\": not in executable format: %s.",
+	     scratch_pathname, bfd_errmsg (bfd_get_error ()));
+    }
+  if (build_section_table (abfd, &so -> sections, &so -> sections_end))
+    {
+      error ("Can't find the file sections in `%s': %s", 
+	     bfd_get_filename (exec_bfd), bfd_errmsg (bfd_get_error ()));
+    }
+
+  for (p = so -> sections; p < so -> sections_end; p++)
+    {
+      /* Relocate the section binding addresses as recorded in the shared
+	 object's file by the offset to get the address to which the
+	 object was actually mapped.  */
+      p -> addr += LM_OFFSET (so);
+      p -> endaddr += LM_OFFSET (so);
+      so -> lmend = (CORE_ADDR) max (p -> endaddr, so -> lmend);
+      if (STREQ (p -> the_bfd_section -> name, ".text"))
+	{
+	  so -> textsection = p;
+	}
+    }
+
+  /* Free the file names, close the file now.  */
+  do_cleanups (old_chain);
+
+  return (1);
+}
+
+/*
+
+LOCAL FUNCTION
+
+	locate_base -- locate the base address of dynamic linker structs
+
+SYNOPSIS
+
+	CORE_ADDR locate_base (void)
+
+DESCRIPTION
+
+	For both the SunOS and SVR4 shared library implementations, if the
+	inferior executable has been linked dynamically, there is a single
+	address somewhere in the inferior's data space which is the key to
+	locating all of the dynamic linker's runtime structures.  This
+	address is the value of the symbol defined by the macro DEBUG_BASE.
+	The job of this function is to find and return that address, or to
+	return 0 if there is no such address (the executable is statically
+	linked for example).
+
+	For SunOS, the job is almost trivial, since the dynamic linker and
+	all of it's structures are statically linked to the executable at
+	link time.  Thus the symbol for the address we are looking for has
+	already been added to the minimal symbol table for the executable's
+	objfile at the time the symbol file's symbols were read, and all we
+	have to do is look it up there.  Note that we explicitly do NOT want
+	to find the copies in the shared library.
+
+	The SVR4 version is much more complicated because the dynamic linker
+	and it's structures are located in the shared C library, which gets
+	run as the executable's "interpreter" by the kernel.  We have to go
+	to a lot more work to discover the address of DEBUG_BASE.  Because
+	of this complexity, we cache the value we find and return that value
+	on subsequent invocations.  Note there is no copy in the executable
+	symbol tables.
+
+	Irix 5 is basically like SunOS.
+
+	Note that we can assume nothing about the process state at the time
+	we need to find this address.  We may be stopped on the first instruc-
+	tion of the interpreter (C shared library), the first instruction of
+	the executable itself, or somewhere else entirely (if we attached
+	to the process for example).
+
+ */
+
+static CORE_ADDR
+locate_base ()
+{
+  struct minimal_symbol *msymbol;
+  CORE_ADDR address = 0;
+
+  msymbol = lookup_minimal_symbol (DEBUG_BASE, NULL, symfile_objfile);
+  if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0))
+    {
+      address = SYMBOL_VALUE_ADDRESS (msymbol);
+    }
+  return (address);
+}
+
+/*
+
+LOCAL FUNCTION
+
+	first_link_map_member -- locate first member in dynamic linker's map
+
+SYNOPSIS
+
+	static struct link_map *first_link_map_member (void)
+
+DESCRIPTION
+
+	Read in a copy of the first member in the inferior's dynamic
+	link map from the inferior's dynamic linker structures, and return
+	a pointer to the link map descriptor.
+*/
+
+static struct link_map *
+first_link_map_member ()
+{
+  struct obj_list *listp;
+  struct obj_list list_old;
+  struct link_map *lm;
+  static struct link_map first_lm;
+  CORE_ADDR lladdr;
+  CORE_ADDR next_lladdr;
+
+  /* We have not already read in the dynamic linking structures
+     from the inferior, lookup the address of the base structure. */
+  debug_base = locate_base ();
+  if (debug_base == 0)
+    return NULL;
+
+  /* Get address of first list entry.  */
+  read_memory (debug_base, (char *) &listp, sizeof (struct obj_list *));
+
+  if (listp == NULL)
+    return NULL;
+
+  /* Get first list entry.  */
+  lladdr = (CORE_ADDR) listp;
+  read_memory (lladdr, (char *) &list_old, sizeof (struct obj_list));
+
+  /* The first entry in the list is the object file we are debugging,
+     so skip it.  */
+  next_lladdr = (CORE_ADDR) list_old.next; 
+
+#ifdef HANDLE_NEW_OBJ_LIST
+  if (list_old.data == NEW_OBJ_INFO_MAGIC)
+    {
+      Elf32_Obj_Info list_32;
+
+      read_memory (lladdr, (char *) &list_32, sizeof (Elf32_Obj_Info));
+      if (list_32.oi_size != sizeof (Elf32_Obj_Info))
+	return NULL;
+      next_lladdr = (CORE_ADDR) list_32.oi_next; 
+    }
+#endif
+
+  if (next_lladdr == 0)
+    return NULL;
+
+  first_lm.l_lladdr = next_lladdr;
+  lm = &first_lm;
+  return lm;
+}
+
+/*
+
+LOCAL FUNCTION
+
+	next_link_map_member -- locate next member in dynamic linker's map
+
+SYNOPSIS
+
+	static struct link_map *next_link_map_member (so_list_ptr)
+
+DESCRIPTION
+
+	Read in a copy of the next member in the inferior's dynamic
+	link map from the inferior's dynamic linker structures, and return
+	a pointer to the link map descriptor.
+*/
+
+static struct link_map *
+next_link_map_member (so_list_ptr)
+     struct so_list *so_list_ptr;
+{
+  struct link_map *lm = &so_list_ptr -> lm;
+  CORE_ADDR next_lladdr = lm -> l_next;
+  static struct link_map next_lm;
+
+  if (next_lladdr == 0)
+    {
+      /* We have hit the end of the list, so check to see if any were
+	 added, but be quiet if we can't read from the target any more. */
+      int status = 0;
+
+      if (lm -> l_variant == OBJ_LIST_OLD)
+	{
+	  struct obj_list list_old;
+
+	  status = target_read_memory (lm -> l_lladdr,
+				       (char *) &list_old,
+				       sizeof (struct obj_list));
+	  next_lladdr = (CORE_ADDR) list_old.next;
+	}
+#ifdef HANDLE_NEW_OBJ_LIST
+      else if (lm -> l_variant == OBJ_LIST_32)
+	{
+	  Elf32_Obj_Info list_32;
+	  status = target_read_memory (lm -> l_lladdr,
+				       (char *) &list_32,
+				       sizeof (Elf32_Obj_Info));
+	  next_lladdr = (CORE_ADDR) list_32.oi_next;
+	}
+#endif
+
+      if (status != 0 || next_lladdr == 0)
+	return NULL;
+    }
+
+  next_lm.l_lladdr = next_lladdr;
+  lm = &next_lm;
+  return lm;
+}
+
+/*
+
+LOCAL FUNCTION
+
+	xfer_link_map_member -- set local variables from dynamic linker's map
+
+SYNOPSIS
+
+	static void xfer_link_map_member (so_list_ptr, lm)
+
+DESCRIPTION
+
+	Read in a copy of the requested member in the inferior's dynamic
+	link map from the inferior's dynamic linker structures, and fill
+	in the necessary so_list_ptr elements.
+*/
+
+static void
+xfer_link_map_member (so_list_ptr, lm)
+     struct so_list *so_list_ptr;
+     struct link_map *lm;
+{
+  struct obj_list list_old;
+  CORE_ADDR lladdr = lm -> l_lladdr;
+  struct link_map *new_lm = &so_list_ptr -> lm;
+  int errcode;
+
+  read_memory (lladdr, (char *) &list_old, sizeof (struct obj_list));
+
+  new_lm -> l_variant = OBJ_LIST_OLD;
+  new_lm -> l_lladdr = lladdr;
+  new_lm -> l_next = (CORE_ADDR) list_old.next; 
+
+#ifdef HANDLE_NEW_OBJ_LIST
+  if (list_old.data == NEW_OBJ_INFO_MAGIC)
+    {
+      Elf32_Obj_Info list_32;
+
+      read_memory (lladdr, (char *) &list_32, sizeof (Elf32_Obj_Info));
+      if (list_32.oi_size != sizeof (Elf32_Obj_Info))
+	return;
+      new_lm -> l_variant = OBJ_LIST_32;
+      new_lm -> l_next = (CORE_ADDR) list_32.oi_next; 
+
+      target_read_string ((CORE_ADDR) list_32.oi_pathname,
+			  &so_list_ptr -> so_name,
+			  list_32.oi_pathname_len + 1, &errcode);
+      if (errcode != 0)
+	memory_error (errcode, (CORE_ADDR) list_32.oi_pathname);
+
+      LM_ADDR (so_list_ptr) = (CORE_ADDR) list_32.oi_ehdr;
+      LM_OFFSET (so_list_ptr) =
+	(CORE_ADDR) list_32.oi_ehdr - (CORE_ADDR) list_32.oi_orig_ehdr;
+    }
+  else
+#endif
+    {
+#if defined (_MIPS_SIM_NABI32) && _MIPS_SIM == _MIPS_SIM_NABI32
+      /* If we are compiling GDB under N32 ABI, the alignments in
+	 the obj struct are different from the O32 ABI and we will get
+	 wrong values when accessing the struct.
+	 As a workaround we use fixed values which are good for
+	 Irix 6.2.  */
+      char buf[432];
+
+      read_memory ((CORE_ADDR) list_old.data, buf, sizeof (buf));
+
+      target_read_string (extract_address (&buf[236], 4),
+			  &so_list_ptr -> so_name,
+			  INT_MAX, &errcode);
+      if (errcode != 0)
+	memory_error (errcode, extract_address (&buf[236], 4));
+
+      LM_ADDR (so_list_ptr) = extract_address (&buf[196], 4);
+      LM_OFFSET (so_list_ptr) =
+	extract_address (&buf[196], 4) - extract_address (&buf[248], 4);
+#else
+      struct obj obj_old;
+
+      read_memory ((CORE_ADDR) list_old.data, (char *) &obj_old,
+		   sizeof (struct obj));
+
+      target_read_string ((CORE_ADDR) obj_old.o_path,
+			  &so_list_ptr -> so_name,
+			  INT_MAX, &errcode);
+      if (errcode != 0)
+	memory_error (errcode, (CORE_ADDR) obj_old.o_path);
+
+      LM_ADDR (so_list_ptr) = (CORE_ADDR) obj_old.o_praw;
+      LM_OFFSET (so_list_ptr) =
+	(CORE_ADDR) obj_old.o_praw - obj_old.o_base_address;
+#endif
+    }
+
+  catch_errors (solib_map_sections, (char *) so_list_ptr,
+		"Error while mapping shared library sections:\n",
+		RETURN_MASK_ALL);
+}
+
+
+/*
+
+LOCAL FUNCTION
+
+	find_solib -- step through list of shared objects
+
+SYNOPSIS
+
+	struct so_list *find_solib (struct so_list *so_list_ptr)
+
+DESCRIPTION
+
+	This module contains the routine which finds the names of any
+	loaded "images" in the current process. The argument in must be
+	NULL on the first call, and then the returned value must be passed
+	in on subsequent calls. This provides the capability to "step" down
+	the list of loaded objects. On the last object, a NULL value is
+	returned.
+ */
+
+static struct so_list *
+find_solib (so_list_ptr)
+     struct so_list *so_list_ptr;	/* Last lm or NULL for first one */
+{
+  struct so_list *so_list_next = NULL;
+  struct link_map *lm = NULL;
+  struct so_list *new;
+  
+  if (so_list_ptr == NULL)
+    {
+      /* We are setting up for a new scan through the loaded images. */
+      if ((so_list_next = so_list_head) == NULL)
+	{
+	  /* Find the first link map list member. */
+	  lm = first_link_map_member ();
+	}
+    }
+  else
+    {
+      /* We have been called before, and are in the process of walking
+	 the shared library list.  Advance to the next shared object. */
+      lm = next_link_map_member (so_list_ptr);
+      so_list_next = so_list_ptr -> next;
+    }
+  if ((so_list_next == NULL) && (lm != NULL))
+    {
+      new = (struct so_list *) xmalloc (sizeof (struct so_list));
+      memset ((char *) new, 0, sizeof (struct so_list));
+      /* Add the new node as the next node in the list, or as the root
+	 node if this is the first one. */
+      if (so_list_ptr != NULL)
+	{
+	  so_list_ptr -> next = new;
+	}
+      else
+	{
+	  so_list_head = new;
+	}      
+      so_list_next = new;
+      xfer_link_map_member (new, lm);
+    }
+  return (so_list_next);
+}
+
+/* A small stub to get us past the arg-passing pinhole of catch_errors.  */
+
+static int
+symbol_add_stub (arg)
+     char *arg;
+{
+  register struct so_list *so = (struct so_list *) arg;	/* catch_errs bogon */
+  CORE_ADDR text_addr = 0;
+
+  if (so -> textsection)
+    text_addr = so -> textsection -> addr;
+  else if (so -> abfd != NULL)
+    {
+      asection *lowest_sect;
+
+      /* If we didn't find a mapped non zero sized .text section, set up
+	 text_addr so that the relocation in symbol_file_add does no harm.  */
+
+      lowest_sect = bfd_get_section_by_name (so -> abfd, ".text");
+      if (lowest_sect == NULL)
+	bfd_map_over_sections (so -> abfd, find_lowest_section,
+			       (PTR) &lowest_sect);
+      if (lowest_sect)
+	text_addr = bfd_section_vma (so -> abfd, lowest_sect) + LM_OFFSET (so);
+    }
+  
+  so -> objfile = symbol_file_add (so -> so_name, so -> from_tty,
+				   text_addr,
+				   0, 0, 0, 0, 0);
+  return (1);
+}
+
+/*
+
+GLOBAL FUNCTION
+
+	solib_add -- add a shared library file to the symtab and section list
+
+SYNOPSIS
+
+	void solib_add (char *arg_string, int from_tty,
+			struct target_ops *target)
+
+DESCRIPTION
+
+*/
+
+void
+solib_add (arg_string, from_tty, target)
+     char *arg_string;
+     int from_tty;
+     struct target_ops *target;
+{	
+  register struct so_list *so = NULL;   	/* link map state variable */
+
+  /* Last shared library that we read.  */
+  struct so_list *so_last = NULL;
+
+  char *re_err;
+  int count;
+  int old;
+  
+  if ((re_err = re_comp (arg_string ? arg_string : ".")) != NULL)
+    {
+      error ("Invalid regexp: %s", re_err);
+    }
+  
+  /* Add the shared library sections to the section table of the
+     specified target, if any.  */
+  if (target)
+    {
+      /* Count how many new section_table entries there are.  */
+      so = NULL;
+      count = 0;
+      while ((so = find_solib (so)) != NULL)
+	{
+	  if (so -> so_name[0])
+	    {
+	      count += so -> sections_end - so -> sections;
+	    }
+	}
+      
+      if (count)
+	{
+	  int update_coreops;
+
+	  /* We must update the to_sections field in the core_ops structure
+	     here, otherwise we dereference a potential dangling pointer
+	     for each call to target_read/write_memory within this routine.  */
+	  update_coreops = core_ops.to_sections == target->to_sections;
+	     
+	  /* Reallocate the target's section table including the new size.  */
+	  if (target -> to_sections)
+	    {
+	      old = target -> to_sections_end - target -> to_sections;
+	      target -> to_sections = (struct section_table *)
+		xrealloc ((char *)target -> to_sections,
+			 (sizeof (struct section_table)) * (count + old));
+	    }
+	  else
+	    {
+	      old = 0;
+	      target -> to_sections = (struct section_table *)
+		xmalloc ((sizeof (struct section_table)) * count);
+	    }
+	  target -> to_sections_end = target -> to_sections + (count + old);
+	  
+	  /* Update the to_sections field in the core_ops structure
+	     if needed.  */
+	  if (update_coreops)
+	    {
+	      core_ops.to_sections = target->to_sections;
+	      core_ops.to_sections_end = target->to_sections_end;
+	    }
+
+	  /* Add these section table entries to the target's table.  */
+	  while ((so = find_solib (so)) != NULL)
+	    {
+	      if (so -> so_name[0])
+		{
+		  count = so -> sections_end - so -> sections;
+		  memcpy ((char *) (target -> to_sections + old),
+			  so -> sections, 
+			  (sizeof (struct section_table)) * count);
+		  old += count;
+		}
+	    }
+	}
+    }
+  
+  /* Now add the symbol files.  */
+  while ((so = find_solib (so)) != NULL)
+    {
+      if (so -> so_name[0] && re_exec (so -> so_name))
+	{
+	  so -> from_tty = from_tty;
+	  if (so -> symbols_loaded)
+	    {
+	      if (from_tty)
+		{
+		  printf_unfiltered ("Symbols already loaded for %s\n", so -> so_name);
+		}
+	    }
+	  else if (catch_errors
+		   (symbol_add_stub, (char *) so,
+		    "Error while reading shared library symbols:\n",
+		    RETURN_MASK_ALL))
+	    {
+	      so_last = so;
+	      so -> symbols_loaded = 1;
+	    }
+	}
+    }
+
+  /* Getting new symbols may change our opinion about what is
+     frameless.  */
+  if (so_last)
+    reinit_frame_cache ();
+}
+
+/*
+
+LOCAL FUNCTION
+
+	info_sharedlibrary_command -- code for "info sharedlibrary"
+
+SYNOPSIS
+
+	static void info_sharedlibrary_command ()
+
+DESCRIPTION
+
+	Walk through the shared library list and print information
+	about each attached library.
+*/
+
+static void
+info_sharedlibrary_command (ignore, from_tty)
+     char *ignore;
+     int from_tty;
+{
+  register struct so_list *so = NULL;  	/* link map state variable */
+  int header_done = 0;
+  
+  if (exec_bfd == NULL)
+    {
+      printf_unfiltered ("No exec file.\n");
+      return;
+    }
+  while ((so = find_solib (so)) != NULL)
+    {
+      if (so -> so_name[0])
+	{
+	  if (!header_done)
+	    {
+	      printf_unfiltered("%-12s%-12s%-12s%s\n", "From", "To", "Syms Read",
+		     "Shared Object Library");
+	      header_done++;
+	    }
+	  printf_unfiltered ("%-12s",
+		  local_hex_string_custom ((unsigned long) LM_ADDR (so),
+					   "08l"));
+	  printf_unfiltered ("%-12s",
+		  local_hex_string_custom ((unsigned long) so -> lmend,
+					   "08l"));
+	  printf_unfiltered ("%-12s", so -> symbols_loaded ? "Yes" : "No");
+	  printf_unfiltered ("%s\n",  so -> so_name);
+	}
+    }
+  if (so_list_head == NULL)
+    {
+      printf_unfiltered ("No shared libraries loaded at this time.\n");	
+    }
+}
+
+/*
+
+GLOBAL FUNCTION
+
+	solib_address -- check to see if an address is in a shared lib
+
+SYNOPSIS
+
+	char *solib_address (CORE_ADDR address)
+
+DESCRIPTION
+
+	Provides a hook for other gdb routines to discover whether or
+	not a particular address is within the mapped address space of
+	a shared library.  Any address between the base mapping address
+	and the first address beyond the end of the last mapping, is
+	considered to be within the shared library address space, for
+	our purposes.
+
+	For example, this routine is called at one point to disable
+	breakpoints which are in shared libraries that are not currently
+	mapped in.
+ */
+
+char *
+solib_address (address)
+     CORE_ADDR address;
+{
+  register struct so_list *so = 0;   	/* link map state variable */
+  
+  while ((so = find_solib (so)) != NULL)
+    {
+      if (so -> so_name[0])
+	{
+	  if ((address >= (CORE_ADDR) LM_ADDR (so)) &&
+	      (address < (CORE_ADDR) so -> lmend))
+	    return (so->so_name);
+	}
+    }
+  return (0);
+}
+
+/* Called by free_all_symtabs */
+
+void 
+clear_solib()
+{
+  struct so_list *next;
+  char *bfd_filename;
+  
+  disable_breakpoints_in_shlibs (1);
+
+  while (so_list_head)
+    {
+      if (so_list_head -> sections)
+	{
+	  free ((PTR)so_list_head -> sections);
+	}
+      if (so_list_head -> abfd)
+	{
+	  bfd_filename = bfd_get_filename (so_list_head -> abfd);
+	  if (!bfd_close (so_list_head -> abfd))
+	    warning ("cannot close \"%s\": %s",
+		     bfd_filename, bfd_errmsg (bfd_get_error ()));
+	}
+      else
+	/* This happens for the executable on SVR4.  */
+	bfd_filename = NULL;
+
+      next = so_list_head -> next;
+      if (bfd_filename)
+	free ((PTR)bfd_filename);
+      free (so_list_head->so_name);
+      free ((PTR)so_list_head);
+      so_list_head = next;
+    }
+  debug_base = 0;
+}
+
+/*
+
+LOCAL FUNCTION
+
+	disable_break -- remove the "mapping changed" breakpoint
+
+SYNOPSIS
+
+	static int disable_break ()
+
+DESCRIPTION
+
+	Removes the breakpoint that gets hit when the dynamic linker
+	completes a mapping change.
+
+*/
+
+static int
+disable_break ()
+{
+  int status = 1;
+
+
+  /* Note that breakpoint address and original contents are in our address
+     space, so we just need to write the original contents back. */
+
+  if (memory_remove_breakpoint (breakpoint_addr, shadow_contents) != 0)
+    {
+      status = 0;
+    }
+
+  /* For the SVR4 version, we always know the breakpoint address.  For the
+     SunOS version we don't know it until the above code is executed.
+     Grumble if we are stopped anywhere besides the breakpoint address. */
+
+  if (stop_pc != breakpoint_addr)
+    {
+      warning ("stopped at unknown breakpoint while handling shared libraries");
+    }
+
+  return (status);
+}
+
+/*
+
+LOCAL FUNCTION
+
+	enable_break -- arrange for dynamic linker to hit breakpoint
+
+SYNOPSIS
+
+	int enable_break (void)
+
+DESCRIPTION
+
+	This functions inserts a breakpoint at the entry point of the
+	main executable, where all shared libraries are mapped in.
+*/
+
+static int
+enable_break ()
+{
+  if (symfile_objfile != NULL
+      && target_insert_breakpoint (symfile_objfile->ei.entry_point,
+				   shadow_contents) == 0)
+    {
+      breakpoint_addr = symfile_objfile->ei.entry_point;
+      return 1;
+    }
+
+  return 0;
+}
+  
+/*
+  
+GLOBAL FUNCTION
+  
+	solib_create_inferior_hook -- shared library startup support
+  
+SYNOPSIS
+  
+	void solib_create_inferior_hook()
+  
+DESCRIPTION
+  
+	When gdb starts up the inferior, it nurses it along (through the
+	shell) until it is ready to execute it's first instruction.  At this
+	point, this function gets called via expansion of the macro
+	SOLIB_CREATE_INFERIOR_HOOK.
+
+	For SunOS executables, this first instruction is typically the
+	one at "_start", or a similar text label, regardless of whether
+	the executable is statically or dynamically linked.  The runtime
+	startup code takes care of dynamically linking in any shared
+	libraries, once gdb allows the inferior to continue.
+
+	For SVR4 executables, this first instruction is either the first
+	instruction in the dynamic linker (for dynamically linked
+	executables) or the instruction at "start" for statically linked
+	executables.  For dynamically linked executables, the system
+	first exec's /lib/libc.so.N, which contains the dynamic linker,
+	and starts it running.  The dynamic linker maps in any needed
+	shared libraries, maps in the actual user executable, and then
+	jumps to "start" in the user executable.
+
+	For both SunOS shared libraries, and SVR4 shared libraries, we
+	can arrange to cooperate with the dynamic linker to discover the
+	names of shared libraries that are dynamically linked, and the
+	base addresses to which they are linked.
+
+	This function is responsible for discovering those names and
+	addresses, and saving sufficient information about them to allow
+	their symbols to be read at a later time.
+
+FIXME
+
+	Between enable_break() and disable_break(), this code does not
+	properly handle hitting breakpoints which the user might have
+	set in the startup code or in the dynamic linker itself.  Proper
+	handling will probably have to wait until the implementation is
+	changed to use the "breakpoint handler function" method.
+
+	Also, what if child has exit()ed?  Must exit loop somehow.
+  */
+
+void 
+solib_create_inferior_hook()
+{
+  if (!enable_break ())
+    {
+      warning ("shared library handler failed to enable breakpoint");
+      return;
+    }
+
+  /* Now run the target.  It will eventually hit the breakpoint, at
+     which point all of the libraries will have been mapped in and we
+     can go groveling around in the dynamic linker structures to find
+     out what we need to know about them. */
+
+  clear_proceed_status ();
+  stop_soon_quietly = 1;
+  stop_signal = TARGET_SIGNAL_0;
+  do
+    {
+      target_resume (-1, 0, stop_signal);
+      wait_for_inferior ();
+    }
+  while (stop_signal != TARGET_SIGNAL_TRAP);
+  
+  /* We are now either at the "mapping complete" breakpoint (or somewhere
+     else, a condition we aren't prepared to deal with anyway), so adjust
+     the PC as necessary after a breakpoint, disable the breakpoint, and
+     add any shared libraries that were mapped in. */
+
+  if (DECR_PC_AFTER_BREAK)
+    {
+      stop_pc -= DECR_PC_AFTER_BREAK;
+      write_register (PC_REGNUM, stop_pc);
+    }
+
+  if (!disable_break ())
+    {
+      warning ("shared library handler failed to disable breakpoint");
+    }
+
+  /*  solib_add will call reinit_frame_cache.
+      But we are stopped in the startup code and we might not have symbols
+      for the startup code, so heuristic_proc_start could be called
+      and will put out an annoying warning.
+      Delaying the resetting of stop_soon_quietly until after symbol loading
+      suppresses the warning.  */
+  if (auto_solib_add)
+    solib_add ((char *) 0, 0, (struct target_ops *) 0);
+  stop_soon_quietly = 0;
+}
+
+/*
+
+LOCAL FUNCTION
+
+	sharedlibrary_command -- handle command to explicitly add library
+
+SYNOPSIS
+
+	static void sharedlibrary_command (char *args, int from_tty)
+
+DESCRIPTION
+
+*/
+
+static void
+sharedlibrary_command (args, from_tty)
+char *args;
+int from_tty;
+{
+  dont_repeat ();
+  solib_add (args, from_tty, (struct target_ops *) 0);
+}
+
+void
+_initialize_solib()
+{
+  add_com ("sharedlibrary", class_files, sharedlibrary_command,
+	   "Load shared object library symbols for files matching REGEXP.");
+  add_info ("sharedlibrary", info_sharedlibrary_command, 
+	    "Status of loaded shared object libraries.");
+
+  add_show_from_set
+    (add_set_cmd ("auto-solib-add", class_support, var_zinteger,
+		  (char *) &auto_solib_add,
+		  "Set autoloading of shared library symbols.\n\
+If nonzero, symbols from all shared object libraries will be loaded\n\
+automatically when the inferior begins execution or when the dynamic linker\n\
+informs gdb that a new library has been loaded.  Otherwise, symbols\n\
+must be loaded manually, using `sharedlibrary'.",
+		  &setlist),
+     &showlist);
+}
+
+
+/* Register that we are able to handle irix5 core file formats.
+   This really is bfd_target_unknown_flavour */
+
+static struct core_fns irix5_core_fns =
+{
+  bfd_target_unknown_flavour,
+  fetch_core_registers,
+  NULL
+};
+
+void
+_initialize_core_irix5 ()
+{
+  add_core_fns (&irix5_core_fns);
+}