New files for Irix 5 support.

1 files changed, 1072 insertions, 0 deletions

diff --git a/gdb/irix5-nat.c b/gdb/irix5-nat.c
new file mode 100644
index 0000000..0ae328f
--- /dev/null
+++ b/gdb/irix5-nat.c
@@ -0,0 +1,1072 @@
+/* Native support for the SGI Iris running IRIX version 5, for GDB.
+   Copyright 1988, 1989, 1990, 1991, 1992, 1993 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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#include "defs.h"
+#include "inferior.h"
+#include "gdbcore.h"
+#include "target.h"
+
+#include <sys/time.h>
+#include <sys/procfs.h>
+#include <setjmp.h>		/* For JB_XXX.  */
+
+/* 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];
+
+  for(regi = 0; regi <= CTX_RA; regi++)
+    supply_register (regi, (char *)(regp + regi));
+
+  supply_register (PC_REGNUM, (char *)(regp + CTX_EPC));
+  supply_register (HI_REGNUM, (char *)(regp + CTX_MDHI));
+  supply_register (LO_REGNUM, (char *)(regp + CTX_MDLO));
+  supply_register (CAUSE_REGNUM, (char *)(regp + CTX_CAUSE));
+}
+
+void
+fill_gregset (gregsetp, regno)
+     gregset_t *gregsetp;
+     int regno;
+{
+  int regi;
+  register greg_t *regp = &(*gregsetp)[0];
+
+  for (regi = 0; regi <= CTX_RA; regi++)
+    if ((regno == -1) || (regno == regi))
+      *(regp + regi) = *(greg_t *) &registers[REGISTER_BYTE (regi)];
+
+  if ((regno == -1) || (regno == PC_REGNUM))
+    *(regp + CTX_EPC) = *(greg_t *) &registers[REGISTER_BYTE (PC_REGNUM)];
+
+  if ((regno == -1) || (regno == CAUSE_REGNUM))
+    *(regp + CTX_CAUSE) = *(greg_t *) &registers[REGISTER_BYTE (PS_REGNUM)];
+
+  if ((regno == -1) || (regno == HI_REGNUM))
+    *(regp + CTX_MDHI) = *(greg_t *) &registers[REGISTER_BYTE (HI_REGNUM)];
+
+  if ((regno == -1) || (regno == LO_REGNUM))
+    *(regp + CTX_MDLO) = *(greg_t *) &registers[REGISTER_BYTE (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;
+
+  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. */
+}
+
+void
+fill_fpregset (fpregsetp, regno)
+     fpregset_t *fpregsetp;
+     int regno;
+{
+  int regi;
+  char *from, *to;
+
+  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;
+}
+
+void
+fetch_core_registers (core_reg_sect, core_reg_size, which, reg_addr)
+     char *core_reg_sect;
+     unsigned core_reg_size;
+     int which;			/* Unused */
+     unsigned int reg_addr;	/* Unused */
+{
+  if (core_reg_size != REGISTER_BYTES)
+    {
+      warning ("wrong size gregset struct in core file");
+      return;
+    }
+
+  memcpy ((char *)registers, core_reg_sect, core_reg_size);
+}
+
+/* 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.  */
+
+#include <sys/types.h>
+#include <signal.h>
+#include <string.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>
+
+#include "symtab.h"
+#include "bfd.h"
+#include "symfile.h"
+#include "objfiles.h"
+#include "command.h"
+#include "frame.h"
+#include "regex.h"
+#include "inferior.h"
+#include "language.h"
+
+/* We need to set a breakpoint at a point when we know that the
+   mapping of shared libraries is complete.  dbx simply breaks at main
+   (or, for FORTRAN, MAIN__), so we do the same.  We can not break at
+   the very beginning of main, because the startup code will jump into
+   main after the GP initialization instructions.  SOLIB_BKPT_OFFSET
+   is used to skip those instructions.  */
+
+#define SOLIB_BKPT_OFFSET 12
+
+static char *bkpt_names[] = {
+  "main",
+  "MAIN__",
+  NULL
+};
+
+/* The symbol which starts off the list of shared libraries.  */
+#define DEBUG_BASE "__rld_obj_head"
+
+/* How to get the loaded address of a shared library.  */
+#define LM_ADDR(so) ((so)->lm.o_base_address)
+
+char shadow_contents[BREAKPOINT_MAX];	/* Stash old bkpt addr contents */
+
+extern CORE_ADDR sigtramp_address, sigtramp_end;
+
+struct so_list {
+  struct so_list *next;			/* next structure in linked list */
+  struct obj_list ll;
+  struct obj lm;			/* copy of link map from inferior */
+  struct obj_list *lladdr;		/* addr in inferior lm was read from */
+  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 obj_list *
+first_link_map_member PARAMS ((void));
+
+static CORE_ADDR
+locate_base PARAMS ((void));
+
+static void
+solib_map_sections PARAMS ((struct so_list *));
+
+/*
+
+LOCAL FUNCTION
+
+	solib_map_sections -- open bfd and build sections for shared lib
+
+SYNOPSIS
+
+	static void 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 void
+solib_map_sections (so)
+     struct so_list *so;
+{
+  char *filename;
+  char *scratch_pathname;
+  int scratch_chan;
+  struct section_table *p;
+  struct cleanup *old_chain;
+  bfd *abfd;
+  
+  filename = tilde_expand (so -> lm.o_path);
+  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_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_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_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 base address to which the object was actually
+	 mapped. */
+      p -> addr += (CORE_ADDR) LM_ADDR (so);
+      p -> endaddr += (CORE_ADDR) LM_ADDR (so);
+      so -> lmend = (CORE_ADDR) max (p -> endaddr, so -> lmend);
+      if (STREQ (p -> sec_ptr -> name, ".text"))
+	{
+	  so -> textsection = p;
+	}
+    }
+
+  /* Free the file names, close the file now.  */
+  do_cleanups (old_chain);
+}
+
+/*
+
+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, 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 copy in our address space.
+*/
+
+static struct obj_list *
+first_link_map_member ()
+{
+  struct obj_list *lm;
+  struct obj_list s;
+
+  read_memory (debug_base, (char *) &lm, sizeof (struct obj_list *));
+
+  if (lm == NULL)
+    return NULL;
+
+  /* The first entry in the list is the object file we are debugging,
+     so skip it.  */
+  read_memory ((CORE_ADDR) lm, (char *) &s, sizeof (struct obj_list));
+
+  return s.next;
+}
+
+/*
+
+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 obj_list *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)
+	{
+	  /* 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)
+	    {
+	      /* Read the base structure in and find the address of 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. */
+      if ((lm = so_list_ptr->ll.next) == NULL)
+	{
+	  /* 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 = target_read_memory ((CORE_ADDR) so_list_ptr -> lladdr,
+					   (char *) &(so_list_ptr -> ll),
+					   sizeof (struct obj_list));
+	  if (status == 0)
+	    {
+	      lm = so_list_ptr->ll.next;
+	    }
+	  else
+	    {
+	      lm = NULL;
+	    }
+	}
+      so_list_next = so_list_ptr -> next;
+    }
+  if ((so_list_next == NULL) && (lm != NULL))
+    {
+      /* Get next link map structure from inferior image and build a local
+	 abbreviated load_map structure */
+      new = (struct so_list *) xmalloc (sizeof (struct so_list));
+      memset ((char *) new, 0, sizeof (struct so_list));
+      new -> lladdr = lm;
+      /* 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;
+      read_memory ((CORE_ADDR) lm, (char *) &(new -> ll),
+		   sizeof (struct obj_list));
+      read_memory ((CORE_ADDR) new->ll.data, (char *) &(new -> lm),
+		   sizeof (struct obj));
+      solib_map_sections (new);
+    }
+  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 */
+  
+  so -> objfile = symbol_file_add (so -> lm.o_path, so -> from_tty,
+				   (unsigned int) so -> textsection -> addr,
+				   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);
+    }
+  
+  /* Getting new symbols may change our opinion about what is
+     frameless.  */
+  reinit_frame_cache ();
+  /* Not to mention where _sigtramp is.  */
+  sigtramp_address = 0;
+  
+  while ((so = find_solib (so)) != NULL)
+    {
+      if (so -> lm.o_path[0] && re_exec (so -> lm.o_path))
+	{
+	  so -> from_tty = from_tty;
+	  if (so -> symbols_loaded)
+	    {
+	      if (from_tty)
+		{
+		  printf_unfiltered ("Symbols already loaded for %s\n", so -> lm.o_path);
+		}
+	    }
+	  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;
+	    }
+	}
+    }
+  
+  /* Now 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 -> lm.o_path[0])
+	    {
+	      count += so -> sections_end - so -> sections;
+	    }
+	}
+      
+      if (count)
+	{
+	  /* 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);
+	  
+	  /* Add these section table entries to the target's table.  */
+	  while ((so = find_solib (so)) != NULL)
+	    {
+	      if (so -> lm.o_path[0])
+		{
+		  count = so -> sections_end - so -> sections;
+		  memcpy ((char *) (target -> to_sections + old),
+			  so -> sections, 
+			  (sizeof (struct section_table)) * count);
+		  old += count;
+		}
+	    }
+	}
+    }
+}
+
+/*
+
+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 -> lm.o_path[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 -> lm.o_path);
+	}
+    }
+  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
+
+	int 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.
+ */
+
+int
+solib_address (address)
+     CORE_ADDR address;
+{
+  register struct so_list *so = 0;   	/* link map state variable */
+  
+  while ((so = find_solib (so)) != NULL)
+    {
+      if (so -> lm.o_path[0])
+	{
+	  if ((address >= (CORE_ADDR) so->lm.o_base_address) &&
+	      (address < (CORE_ADDR) so -> lmend))
+	    {
+	      return (1);
+	    }
+	}
+    }
+  return (0);
+}
+
+/* Called by free_all_symtabs */
+
+void 
+clear_solib()
+{
+  struct so_list *next;
+  char *bfd_filename;
+  
+  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);
+	  bfd_close (so_list_head -> abfd);
+	}
+      else
+	/* This happens for the executable on SVR4.  */
+	bfd_filename = NULL;
+      
+      next = so_list_head -> next;
+      if (bfd_filename)
+	free ((PTR)bfd_filename);
+      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
+
+	Both the SunOS and the SVR4 dynamic linkers have, as part of their
+	debugger interface, support for arranging for the inferior to hit
+	a breakpoint after mapping in the shared libraries.  This function
+	enables that breakpoint.
+
+	For SunOS, there is a special flag location (in_debugger) which we
+	set to 1.  When the dynamic linker sees this flag set, it will set
+	a breakpoint at a location known only to itself, after saving the
+	original contents of that place and the breakpoint address itself,
+	in it's own internal structures.  When we resume the inferior, it
+	will eventually take a SIGTRAP when it runs into the breakpoint.
+	We handle this (in a different place) by restoring the contents of
+	the breakpointed location (which is only known after it stops),
+	chasing around to locate the shared libraries that have been
+	loaded, then resuming.
+
+	For SVR4, the debugger interface structure contains a member (r_brk)
+	which is statically initialized at the time the shared library is
+	built, to the offset of a function (_r_debug_state) which is guaran-
+	teed to be called once before mapping in a library, and again when
+	the mapping is complete.  At the time we are examining this member,
+	it contains only the unrelocated offset of the function, so we have
+	to do our own relocation.  Later, when the dynamic linker actually
+	runs, it relocates r_brk to be the actual address of _r_debug_state().
+
+	The debugger interface structure also contains an enumeration which
+	is set to either RT_ADD or RT_DELETE prior to changing the mapping,
+	depending upon whether or not the library is being mapped or unmapped,
+	and then set to RT_CONSISTENT after the library is mapped/unmapped.
+
+	Irix 5, on the other hand, has no such features.  Instead, we
+	set a breakpoint at main.
+*/
+
+static int
+enable_break ()
+{
+  int success = 0;
+  struct minimal_symbol *msymbol;
+  char **bkpt_namep;
+  CORE_ADDR bkpt_addr;
+
+  /* Scan through the list of symbols, trying to look up the symbol and
+     set a breakpoint there.  Terminate loop when we/if we succeed. */
+
+  breakpoint_addr = 0;
+  for (bkpt_namep = bkpt_names; *bkpt_namep != NULL; bkpt_namep++)
+    {
+      msymbol = lookup_minimal_symbol (*bkpt_namep, symfile_objfile);
+      if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0))
+	{
+	  bkpt_addr = SYMBOL_VALUE_ADDRESS (msymbol);
+#ifdef SOLIB_BKPT_OFFSET
+	  /* We only want to skip if bkpt_addr is currently pointing
+	     at a GP setting instruction.  */
+	  {
+	    char buf[4];
+
+	    if (target_read_memory (bkpt_addr, buf, 4) == 0)
+	      {
+		unsigned long insn;
+
+		insn = extract_unsigned_integer (buf, 4);
+		if ((insn & 0xffff0000) == 0x3c1c0000) /* lui $gp,n */
+		  bkpt_addr += SOLIB_BKPT_OFFSET;
+	      }
+	  }
+#endif
+	  if (target_insert_breakpoint (bkpt_addr, shadow_contents) == 0)
+	    {
+	      breakpoint_addr = bkpt_addr;
+	      success = 1;
+	      break;
+	    }
+	}
+    }
+
+  return (success);
+}
+  
+/*
+  
+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 = 0;
+  do
+    {
+      target_resume (-1, 0, stop_signal);
+      wait_for_inferior ();
+    }
+  while (stop_signal != SIGTRAP);
+  stop_soon_quietly = 0;
+  
+  /* 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 ((char *) 0, 0, (struct target_ops *) 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.");
+}