Initial revision

1 files changed, 1186 insertions, 0 deletions

diff --git a/gdb/source.c b/gdb/source.c
new file mode 100644
index 0000000..ebc7041
--- /dev/null
+++ b/gdb/source.c
@@ -0,0 +1,1186 @@
+/* List lines of source files for GDB, the GNU debugger.
+   Copyright (C) 1986, 1987, 1988, 1989, 1991 Free Software Foundation, Inc.
+
+This file is part of GDB.
+
+GDB 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 1, or (at your option)
+any later version.
+
+GDB 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 GDB; see the file COPYING.  If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#include <stdio.h>
+#include "defs.h"
+#include "symtab.h"
+#include "param.h"
+#include "command.h"
+#include "frame.h"
+
+#ifdef USG
+#include <sys/types.h>
+#endif
+
+#include <string.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include "gdbcore.h"
+
+extern char *strstr();
+
+extern void set_next_address ();
+
+void mod_path ();
+
+/* Path of directories to search for source files.
+   Same format as the PATH environment variable's value.  */
+
+char *source_path;
+
+/* Symtab of default file for listing lines of.  */
+
+struct symtab *current_source_symtab;
+
+/* Default next line to list.  */
+
+int current_source_line;
+
+/* Line number of last line printed.  Default for various commands.
+   current_source_line is usually, but not always, the same as this.  */
+
+static int last_line_listed;
+
+/* First line number listed by last listing command.  */
+
+static int first_line_listed;
+
+
+/* Set the source file default for the "list" command, specifying a
+   symtab.  Sigh.  Behavior specification: If it is called with a
+   non-zero argument, that is the symtab to select.  If it is not,
+   first lookup "main"; if it exists, use the symtab and line it
+   defines.  If not, take the last symtab in the symtab_list (if it
+   exists) or the last symtab in the psymtab_list (if *it* exists).  If
+   none of this works, report an error.   */
+
+void
+select_source_symtab (s)
+     register struct symtab *s;
+{
+  struct symtabs_and_lines sals;
+  struct symtab_and_line sal;
+  struct partial_symtab *ps;
+  struct partial_symtab *cs_pst = 0;
+  
+  if (s)
+    {
+      current_source_symtab = s;
+      current_source_line = 1;
+      return;
+    }
+
+  /* Make the default place to list be the function `main'
+     if one exists.  */
+  if (lookup_symbol ("main", 0, VAR_NAMESPACE, 0, NULL))
+    {
+      sals = decode_line_spec ("main", 1);
+      sal = sals.sals[0];
+      free (sals.sals);
+      current_source_symtab = sal.symtab;
+      current_source_line = max (sal.line - (lines_to_list () - 1), 1);
+      return;
+    }
+  
+  /* All right; find the last file in the symtab list (ignoring .h's).  */
+
+  if (s = symtab_list)
+    {
+      do
+	{
+	  char *name = s->filename;
+	  int len = strlen (name);
+	  if (! (len > 2 && !strcmp (&name[len - 2], ".h")))
+	    current_source_symtab = s;
+	  s = s->next;
+	}
+      while (s);
+      current_source_line = 1;
+    }
+  else if (partial_symtab_list)
+    {
+      ps = partial_symtab_list;
+      while (ps)
+	{
+	  char *name = ps->filename;
+	  int len = strlen (name);
+	  if (! (len > 2 && !strcmp (&name[len - 2], ".h")))
+	    cs_pst = ps;
+	  ps = ps->next;
+	}
+      if (cs_pst)
+	if (cs_pst->readin)
+	  fatal ("Internal: select_source_symtab: readin pst found and no symtabs.");
+	else
+	  current_source_symtab = PSYMTAB_TO_SYMTAB (cs_pst);
+      else
+	current_source_symtab = 0;
+      current_source_line = 1;
+    }
+}
+
+static void
+directories_info ()
+{
+  printf ("Source directories searched: %s\n", source_path);
+}
+
+/* Forget what we learned about line positions in source files,
+   and which directories contain them;
+   must check again now since files may be found in
+   a different directory now.  */
+
+void
+forget_cached_source_info ()
+{
+  register struct symtab *s;
+
+  for (s = symtab_list; s; s = s->next)
+    {
+      if (s->line_charpos != 0)
+	{
+	  free (s->line_charpos);
+	  s->line_charpos = 0;
+	}
+      if (s->fullname != 0)
+	{
+	  free (s->fullname);
+	  s->fullname = 0;
+	}
+    }
+}
+
+void
+init_source_path ()
+{
+  source_path = savestring ("$cdir:$cwd", /* strlen of it */ 10);
+  forget_cached_source_info ();
+}
+
+/* Add zero or more directories to the front of the source path.  */
+ 
+void
+directory_command (dirname, from_tty)
+     char *dirname;
+     int from_tty;
+{
+  dont_repeat ();
+  /* FIXME, this goes to "delete dir"... */
+  if (dirname == 0)
+    {
+      if (query ("Reinitialize source path to empty? ", ""))
+	{
+	  free (source_path);
+	  init_source_path ();
+	}
+    }
+  else
+    mod_path (dirname, from_tty, &source_path);
+  if (from_tty)
+    directories_info ();
+  forget_cached_source_info ();
+}
+
+/* Add zero or more directories to the front of an arbitrary path.  */
+
+void
+mod_path (dirname, from_tty, which_path)
+     char *dirname;
+     int from_tty;
+     char **which_path;
+{
+  char *old = *which_path;
+  int prefix = 0;
+
+  if (dirname == 0)
+    return;
+
+  dirname = strsave (dirname);
+  make_cleanup (free, dirname);
+
+  do
+    {
+      extern char *index ();
+      char *name = dirname;
+      register char *p;
+      struct stat st;
+
+      {
+	char *colon = index (name, ':');
+	char *space = index (name, ' ');
+	char *tab = index (name, '\t');
+	if (colon == 0 && space == 0 && tab ==  0)
+	  p = dirname = name + strlen (name);
+	else
+	  {
+	    p = 0;
+	    if (colon != 0 && (p == 0 || colon < p))
+	      p = colon;
+	    if (space != 0 && (p == 0 || space < p))
+	      p = space;
+	    if (tab != 0 && (p == 0 || tab < p))
+	      p = tab;
+	    dirname = p + 1;
+	    while (*dirname == ':' || *dirname == ' ' || *dirname == '\t')
+	      ++dirname;
+	  }
+      }
+
+      if (p[-1] == '/')
+	/* Sigh. "foo/" => "foo" */
+	--p;
+      *p = '\0';
+
+      while (p[-1] == '.')
+	{
+	  if (p - name == 1)
+	    {
+	      /* "." => getwd ().  */
+	      name = current_directory;
+	      goto append;
+	    }
+	  else if (p[-2] == '/')
+	    {
+	      if (p - name == 2)
+		{
+		  /* "/." => "/".  */
+		  *--p = '\0';
+		  goto append;
+		}
+	      else
+		{
+		  /* "...foo/." => "...foo".  */
+		  p -= 2;
+		  *p = '\0';
+		  continue;
+		}
+	    }
+	  else
+	    break;
+	}
+
+      if (name[0] == '~')
+	name = tilde_expand (name);
+      else if (name[0] != '/' && name[0] != '$')
+	name = concat (current_directory, "/", name);
+      else
+	name = savestring (name, p - name);
+      make_cleanup (free, name);
+
+      /* Unless it's a variable, check existence.  */
+      if (name[0] != '$') {
+	if (stat (name, &st) < 0)
+	  perror_with_name (name);
+	if ((st.st_mode & S_IFMT) != S_IFDIR)
+	  error ("%s is not a directory.", name);
+      }
+
+    append:
+      {
+	register unsigned int len = strlen (name);
+
+	p = *which_path;
+	while (1)
+	  {
+	    if (!strncmp (p, name, len)
+		&& (p[len] == '\0' || p[len] == ':'))
+	      {
+		/* Found it in the search path, remove old copy */
+		if (p > *which_path)
+		  p--;			/* Back over leading colon */
+		if (prefix > p - *which_path)
+		  goto skip_dup;	/* Same dir twice in one cmd */
+		strcpy (p, &p[len+1]);	/* Copy from next \0 or  : */
+	      }
+	    p = index (p, ':');
+	    if (p != 0)
+	      ++p;
+	    else
+	      break;
+	  }
+	if (p == 0)
+	  {
+	    /* If we have already tacked on a name(s) in this command,			   be sure they stay on the front as we tack on some more.  */
+	    if (prefix)
+	      {
+		char *temp, c;
+
+		c = old[prefix];
+		old[prefix] = '\0';
+		temp = concat (old, ":", name);
+		old[prefix] = c;
+		*which_path = concat (temp, "", &old[prefix]);
+		prefix = strlen (temp);
+		free (temp);
+	      }
+	    else
+	      {
+		*which_path = concat (name, (old[0]? ":" : old), old);
+		prefix = strlen (name);
+	      }
+	    free (old);
+	    old = *which_path;
+	  }
+      }
+  skip_dup: ;
+    } while (*dirname != '\0');
+}
+
+
+static void
+source_info ()
+{
+  register struct symtab *s = current_source_symtab;
+
+  if (!s)
+    {
+      printf("No current source file.\n");
+      return;
+    }
+  printf ("Current source file is %s\n", s->filename);
+  if (s->dirname)
+    printf ("Compilation directory is %s\n", s->dirname);
+  if (s->fullname)
+    printf ("Located in %s\n", s->fullname);
+  if (s->nlines)
+    printf ("Contains %d lines\n", s->nlines);
+
+  switch (s->language) {
+  case language_c:
+    printf("Written in the C language.\n");
+  /* Add more cases here when -Wswitch complains... */
+  case language_unknown:
+    break;
+  }
+}
+
+
+
+/* Open a file named STRING, searching path PATH (dir names sep by colons)
+   using mode MODE and protection bits PROT in the calls to open.
+   If TRY_CWD_FIRST, try to open ./STRING before searching PATH.
+   (ie pretend the first element of PATH is ".")
+   If FILENAMED_OPENED is non-null, set it to a newly allocated string naming
+   the actual file opened (this string will always start with a "/".  We
+   have to take special pains to avoid doubling the "/" between the directory
+   and the file, sigh!  Emacs gets confuzzed by this when we print the
+   source file name!!! 
+
+   If a file is found, return the descriptor.
+   Otherwise, return -1, with errno set for the last name we tried to open.  */
+
+/*  >>>> This should only allow files of certain types,
+    >>>>  eg executable, non-directory */
+int
+openp (path, try_cwd_first, string, mode, prot, filename_opened)
+     char *path;
+     int try_cwd_first;
+     char *string;
+     int mode;
+     int prot;
+     char **filename_opened;
+{
+  register int fd;
+  register char *filename;
+  register char *p, *p1;
+  register int len;
+  int alloclen;
+
+  if (!path)
+    path = ".";
+
+  /* ./foo => foo */
+  while (string[0] == '.' && string[1] == '/')
+    string += 2;
+
+  if (try_cwd_first || string[0] == '/')
+    {
+      filename = string;
+      fd = open (filename, mode, prot);
+      if (fd >= 0 || string[0] == '/')
+	goto done;
+    }
+
+  alloclen = strlen (path) + strlen (string) + 2;
+  filename = (char *) alloca (alloclen);
+  fd = -1;
+  for (p = path; p; p = p1 ? p1 + 1 : 0)
+    {
+      p1 = (char *) index (p, ':');
+      if (p1)
+	len = p1 - p;
+      else
+	len = strlen (p);
+
+      if (len == 4 && p[0] == '$' && p[1] == 'c'
+	           && p[2] == 'w' && p[3] == 'd') {
+	/* Name is $cwd -- insert current directory name instead.  */
+	int newlen;
+
+	/* First, realloc the filename buffer if too short. */
+	len = strlen (current_directory);
+	newlen = len + strlen (string) + 2;
+	if (newlen > alloclen) {
+	  alloclen = newlen;
+	  filename = (char *) alloca (alloclen);
+	}
+	strcpy (filename, current_directory);
+      } else {
+	/* Normal file name in path -- just use it.  */
+	strncpy (filename, p, len);
+	filename[len] = 0;
+      }
+
+      /* Beware the // my son, the Emacs barfs, the botch that catch... */
+      while (len > 1 && filename[len-1] == '/')
+	filename[--len] = 0;
+      strcat (filename+len, "/");
+      strcat (filename, string);
+
+      fd = open (filename, mode, prot);
+      if (fd >= 0) break;
+    }
+
+ done:
+  if (filename_opened)
+    if (fd < 0)
+      *filename_opened = (char *) 0;
+    else if (filename[0] == '/')
+      *filename_opened = savestring (filename, strlen (filename));
+    else
+      {
+	/* Beware the // my son, the Emacs barfs, the botch that catch... */
+	   
+	*filename_opened = concat (current_directory, 
+	   '/' == current_directory[strlen(current_directory)-1]? "": "/",
+				   filename);
+      }
+
+  return fd;
+}
+
+/* Open a source file given a symtab S.  Returns a file descriptor
+   or negative number for error.  */
+int
+open_source_file (s)
+     struct symtab *s;
+{
+  char *path = source_path;
+  char *p;
+  int result;
+
+  /* Quick way out if we already know its full name */
+  if (s->fullname) 
+    {
+      result = open (s->fullname, O_RDONLY);
+      if (result >= 0)
+        return result;
+      /* Didn't work -- free old one, try again. */
+      free (s->fullname);
+      s->fullname = NULL;
+    }
+
+  if (s->dirname != NULL)
+    {
+      /* Replace a path entry of  $cdir  with the compilation directory name */
+#define	cdir_len	5
+      p = strstr (source_path, "$cdir");
+      if (p && (p == path || p[-1] == ':')
+	    && (p[cdir_len] == ':' || p[cdir_len] == '\0')) {
+	int len;
+
+	path = (char *)
+	       alloca (strlen (source_path) + 1 + strlen (s->dirname) + 1);
+	len = p - source_path;
+	strncpy (path, source_path, len);		/* Before $cdir */
+	strcpy (path + len, s->dirname);		/* new stuff */
+	strcat (path + len, source_path + len + cdir_len); /* After $cdir */
+      }
+    }
+
+  return openp (path, 0, s->filename, O_RDONLY, 0, &s->fullname);
+}
+
+
+/* Create and initialize the table S->line_charpos that records
+   the positions of the lines in the source file, which is assumed
+   to be open on descriptor DESC.
+   All set S->nlines to the number of such lines.  */
+
+static void
+find_source_lines (s, desc)
+     struct symtab *s;
+     int desc;
+{
+  struct stat st;
+  register char *data, *p, *end;
+  int nlines = 0;
+  int lines_allocated = 1000;
+  int *line_charpos = (int *) xmalloc (lines_allocated * sizeof (int));
+
+  if (fstat (desc, &st) < 0)
+    perror_with_name (s->filename);
+  if (exec_bfd && bfd_get_mtime(exec_bfd) < st.st_mtime)
+    printf ("Source file is more recent than executable.\n");
+
+#if defined (BROKEN_LARGE_ALLOCA)
+  data = (char *) xmalloc (st.st_size);
+  make_cleanup (free, data);
+#else
+  data = (char *) alloca (st.st_size);
+#endif
+  if (myread (desc, data, st.st_size) < 0)
+    perror_with_name (s->filename);
+  end = data + st.st_size;
+  p = data;
+  line_charpos[0] = 0;
+  nlines = 1;
+  while (p != end)
+    {
+      if (*p++ == '\n'
+	  /* A newline at the end does not start a new line.  */
+	  && p != end)
+	{
+	  if (nlines == lines_allocated)
+	    {
+	      lines_allocated *= 2;
+	      line_charpos = (int *) xrealloc (line_charpos,
+					       sizeof (int) * lines_allocated);
+	    }
+	  line_charpos[nlines++] = p - data;
+	}
+    }
+  s->nlines = nlines;
+  s->line_charpos = (int *) xrealloc (line_charpos, nlines * sizeof (int));
+}
+
+/* Return the character position of a line LINE in symtab S.
+   Return 0 if anything is invalid.  */
+
+int
+source_line_charpos (s, line)
+     struct symtab *s;
+     int line;
+{
+  if (!s) return 0;
+  if (!s->line_charpos || line <= 0) return 0;
+  if (line > s->nlines)
+    line = s->nlines;
+  return s->line_charpos[line - 1];
+}
+
+/* Return the line number of character position POS in symtab S.  */
+
+int
+source_charpos_line (s, chr)
+    register struct symtab *s;
+    register int chr;
+{
+  register int line = 0;
+  register int *lnp;
+    
+  if (s == 0 || s->line_charpos == 0) return 0;
+  lnp = s->line_charpos;
+  /* Files are usually short, so sequential search is Ok */
+  while (line < s->nlines  && *lnp <= chr)
+    {
+      line++;
+      lnp++;
+    }
+  if (line >= s->nlines)
+    line = s->nlines;
+  return line;
+}
+
+/* Get full pathname and line number positions for a symtab.
+   Return nonzero if line numbers may have changed.
+   Set *FULLNAME to actual name of the file as found by `openp',
+   or to 0 if the file is not found.  */
+
+int
+get_filename_and_charpos (s, fullname)
+     struct symtab *s;
+     char **fullname;
+{
+  register int desc, linenums_changed = 0;
+  
+  desc = open_source_file (s);
+  if (desc < 0)
+    {
+      if (fullname)
+	*fullname = NULL;
+      return 0;
+    }  
+  if (fullname)
+    *fullname = s->fullname;
+  if (s->line_charpos == 0) linenums_changed = 1;
+  if (linenums_changed) find_source_lines (s, desc);
+  close (desc);
+  return linenums_changed;
+}
+
+/* Print text describing the full name of the source file S
+   and the line number LINE and its corresponding character position.
+   The text starts with two Ctrl-z so that the Emacs-GDB interface
+   can easily find it.
+
+   MID_STATEMENT is nonzero if the PC is not at the beginning of that line.
+
+   Return 1 if successful, 0 if could not find the file.  */
+
+int
+identify_source_line (s, line, mid_statement)
+     struct symtab *s;
+     int line;
+     int mid_statement;
+{
+  if (s->line_charpos == 0)
+    get_filename_and_charpos (s, (char **)NULL);
+  if (s->fullname == 0)
+    return 0;
+  printf ("\032\032%s:%d:%d:%s:0x%x\n", s->fullname,
+	  line, s->line_charpos[line - 1],
+	  mid_statement ? "middle" : "beg",
+	  get_frame_pc (get_current_frame()));
+  current_source_line = line;
+  first_line_listed = line;
+  last_line_listed = line;
+  current_source_symtab = s;
+  return 1;
+}
+
+/* Print source lines from the file of symtab S,
+   starting with line number LINE and stopping before line number STOPLINE.  */
+
+void
+print_source_lines (s, line, stopline, noerror)
+     struct symtab *s;
+     int line, stopline;
+     int noerror;
+{
+  register int c;
+  register int desc;
+  register FILE *stream;
+  int nlines = stopline - line;
+
+  /* Regardless of whether we can open the file, set current_source_symtab. */
+  current_source_symtab = s;
+  current_source_line = line;
+  first_line_listed = line;
+
+  desc = open_source_file (s);
+  if (desc < 0)
+    {
+      if (! noerror) {
+	char *name = alloca (strlen (s->filename) + 100);
+	sprintf (name, "%s:%d", s->filename, line);
+        print_sys_errmsg (name, errno);
+      }
+      return;
+    }
+
+  if (s->line_charpos == 0)
+    find_source_lines (s, desc);
+
+  if (line < 1 || line > s->nlines)
+    {
+      close (desc);
+      error ("Line number %d out of range; %s has %d lines.",
+	     line, s->filename, s->nlines);
+    }
+
+  if (lseek (desc, s->line_charpos[line - 1], 0) < 0)
+    {
+      close (desc);
+      perror_with_name (s->filename);
+    }
+
+  stream = fdopen (desc, "r");
+  clearerr (stream);
+
+  while (nlines-- > 0)
+    {
+      c = fgetc (stream);
+      if (c == EOF) break;
+      last_line_listed = current_source_line;
+      printf_filtered ("%d\t", current_source_line++);
+      do
+	{
+	  if (c < 040 && c != '\t' && c != '\n')
+	      printf_filtered ("^%c", c + 0100);
+	  else if (c == 0177)
+	    printf_filtered ("^?");
+	  else
+	    printf_filtered ("%c", c);
+	} while (c != '\n' && (c = fgetc (stream)) >= 0);
+    }
+
+  fclose (stream);
+}
+
+
+
+/* 
+  C++
+  Print a list of files and line numbers which a user may choose from
+  in order to list a function which was specified ambiguously
+  (as with `list classname::overloadedfuncname', for example).
+  The vector in SALS provides the filenames and line numbers.
+  */
+static void
+ambiguous_line_spec (sals)
+     struct symtabs_and_lines *sals;
+{
+  int i;
+
+  for (i = 0; i < sals->nelts; ++i)
+    printf("file: \"%s\", line number: %d\n",
+	   sals->sals[i].symtab->filename, sals->sals[i].line);
+}
+
+
+static void
+list_command (arg, from_tty)
+     char *arg;
+     int from_tty;
+{
+  struct symtabs_and_lines sals, sals_end;
+  struct symtab_and_line sal, sal_end;
+  struct symbol *sym;
+  char *arg1;
+  int no_end = 1;
+  int dummy_end = 0;
+  int dummy_beg = 0;
+  int linenum_beg = 0;
+  char *p;
+
+  if (symtab_list == 0 && partial_symtab_list == 0)
+    error ("No symbol table is loaded.  Use the \"symbol-file\" command.");
+
+  /* Pull in a current source symtab if necessary */
+  if (current_source_symtab == 0 &&
+      (arg == 0 || arg[0] == '+' || arg[0] == '-'))
+    select_source_symtab (0);
+
+  /* "l" or "l +" lists next ten lines.  */
+
+  if (arg == 0 || !strcmp (arg, "+"))
+    {
+      if (current_source_symtab == 0)
+	error ("No default source file yet.  Do \"help list\".");
+      print_source_lines (current_source_symtab, current_source_line,
+			  current_source_line + lines_to_list (), 0);
+      return;
+    }
+
+  /* "l -" lists previous ten lines, the ones before the ten just listed.  */
+  if (!strcmp (arg, "-"))
+    {
+      if (current_source_symtab == 0)
+	error ("No default source file yet.  Do \"help list\".");
+      print_source_lines (current_source_symtab,
+			  max (first_line_listed - lines_to_list (), 1),
+			  first_line_listed, 0);
+      return;
+    }
+
+  /* Now if there is only one argument, decode it in SAL
+     and set NO_END.
+     If there are two arguments, decode them in SAL and SAL_END
+     and clear NO_END; however, if one of the arguments is blank,
+     set DUMMY_BEG or DUMMY_END to record that fact.  */
+
+  arg1 = arg;
+  if (*arg1 == ',')
+    dummy_beg = 1;
+  else
+    {
+      sals = decode_line_1 (&arg1, 0, 0, 0);
+
+      if (! sals.nelts) return;  /*  C++  */
+      if (sals.nelts > 1)
+	{
+	  ambiguous_line_spec (&sals);
+	  free (sals.sals);
+	  return;
+	}
+
+      sal = sals.sals[0];
+      free (sals.sals);
+    }
+
+  /* Record whether the BEG arg is all digits.  */
+
+  for (p = arg; p != arg1 && *p >= '0' && *p <= '9'; p++);
+  linenum_beg = (p == arg1);
+
+  while (*arg1 == ' ' || *arg1 == '\t')
+    arg1++;
+  if (*arg1 == ',')
+    {
+      no_end = 0;
+      arg1++;
+      while (*arg1 == ' ' || *arg1 == '\t')
+	arg1++;
+      if (*arg1 == 0)
+	dummy_end = 1;
+      else
+	{
+	  if (dummy_beg)
+	    sals_end = decode_line_1 (&arg1, 0, 0, 0);
+	  else
+	    sals_end = decode_line_1 (&arg1, 0, sal.symtab, sal.line);
+	  if (sals_end.nelts == 0) 
+	    return;
+	  if (sals_end.nelts > 1)
+	    {
+	      ambiguous_line_spec (&sals_end);
+	      free (sals_end.sals);
+	      return;
+	    }
+	  sal_end = sals_end.sals[0];
+	  free (sals_end.sals);
+	}
+    }
+
+  if (*arg1)
+    error ("Junk at end of line specification.");
+
+  if (!no_end && !dummy_beg && !dummy_end
+      && sal.symtab != sal_end.symtab)
+    error ("Specified start and end are in different files.");
+  if (dummy_beg && dummy_end)
+    error ("Two empty args do not say what lines to list.");
+ 
+  /* if line was specified by address,
+     first print exactly which line, and which file.
+     In this case, sal.symtab == 0 means address is outside
+     of all known source files, not that user failed to give a filename.  */
+  if (*arg == '*')
+    {
+      if (sal.symtab == 0)
+	error ("No source file for address 0x%x.", sal.pc);
+      sym = find_pc_function (sal.pc);
+      if (sym)
+	printf ("0x%x is in %s (%s, line %d).\n",
+		sal.pc, SYMBOL_NAME (sym), sal.symtab->filename, sal.line);
+      else
+	printf ("0x%x is in %s, line %d.\n",
+		sal.pc, sal.symtab->filename, sal.line);
+    }
+
+  /* If line was not specified by just a line number,
+     and it does not imply a symtab, it must be an undebuggable symbol
+     which means no source code.  */
+
+  if (! linenum_beg && sal.symtab == 0)
+    error ("No line number known for %s.", arg);
+
+  /* If this command is repeated with RET,
+     turn it into the no-arg variant.  */
+
+  if (from_tty)
+    *arg = 0;
+
+  if (dummy_beg && sal_end.symtab == 0)
+    error ("No default source file yet.  Do \"help list\".");
+  if (dummy_beg)
+    print_source_lines (sal_end.symtab,
+			max (sal_end.line - (lines_to_list () - 1), 1),
+			sal_end.line + 1, 0);
+  else if (sal.symtab == 0)
+    error ("No default source file yet.  Do \"help list\".");
+  else if (no_end)
+    print_source_lines (sal.symtab,
+			max (sal.line - (lines_to_list () / 2), 1),
+			sal.line + 5, 0);
+  else
+    print_source_lines (sal.symtab, sal.line,
+			(dummy_end
+			 ? sal.line + lines_to_list ()
+			 : sal_end.line + 1),
+			0);
+}
+
+/* Print info on range of pc's in a specified line.  */
+
+static void
+line_info (arg, from_tty)
+     char *arg;
+     int from_tty;
+{
+  struct symtabs_and_lines sals;
+  struct symtab_and_line sal;
+  CORE_ADDR start_pc, end_pc;
+  int i;
+
+  if (arg == 0)
+    {
+      sal.symtab = current_source_symtab;
+      sal.line = last_line_listed;
+      sals.nelts = 1;
+      sals.sals = (struct symtab_and_line *)
+	xmalloc (sizeof (struct symtab_and_line));
+      sals.sals[0] = sal;
+    }
+  else
+    {
+      sals = decode_line_spec_1 (arg, 0);
+      
+      /* If this command is repeated with RET,
+	 turn it into the no-arg variant.  */
+      if (from_tty)
+	*arg = 0;
+    }
+
+  /* C++  More than one line may have been specified, as when the user
+     specifies an overloaded function name. Print info on them all. */
+  for (i = 0; i < sals.nelts; i++)
+    {
+      sal = sals.sals[i];
+      
+      if (sal.symtab == 0)
+	error ("No source file specified.");
+
+      if (sal.line > 0
+	  && find_line_pc_range (sal.symtab, sal.line, &start_pc, &end_pc))
+	{
+	  if (start_pc == end_pc)
+	    printf ("Line %d of \"%s\" is at pc 0x%x but contains no code.\n",
+		    sal.line, sal.symtab->filename, start_pc);
+	  else
+	    printf ("Line %d of \"%s\" starts at pc 0x%x and ends at 0x%x.\n",
+		    sal.line, sal.symtab->filename, start_pc, end_pc);
+	  /* x/i should display this line's code.  */
+	  set_next_address (start_pc);
+	  /* Repeating "info line" should do the following line.  */
+	  last_line_listed = sal.line + 1;
+	}
+      else
+	printf ("Line number %d is out of range for \"%s\".\n",
+		sal.line, sal.symtab->filename);
+    }
+}
+
+/* Commands to search the source file for a regexp.  */
+
+static void
+forward_search_command (regex, from_tty)
+     char *regex;
+     int from_tty;
+{
+  register int c;
+  register int desc;
+  register FILE *stream;
+  int line = last_line_listed + 1;
+  char *msg;
+
+  msg = (char *) re_comp (regex);
+  if (msg)
+    error (msg);
+
+  if (current_source_symtab == 0)
+    select_source_symtab (0);
+
+  /* Search from last_line_listed+1 in current_source_symtab */
+
+  desc = open_source_file (current_source_symtab);
+  if (desc < 0)
+    perror_with_name (current_source_symtab->filename);
+
+  if (current_source_symtab->line_charpos == 0)
+    find_source_lines (current_source_symtab, desc);
+
+  if (line < 1 || line > current_source_symtab->nlines)
+    {
+      close (desc);
+      error ("Expression not found");
+    }
+
+  if (lseek (desc, current_source_symtab->line_charpos[line - 1], 0) < 0)
+    {
+      close (desc);
+      perror_with_name (current_source_symtab->filename);
+    }
+
+  stream = fdopen (desc, "r");
+  clearerr (stream);
+  while (1) {
+    char buf[4096];		/* Should be reasonable??? */
+    register char *p = buf;
+
+    c = fgetc (stream);
+    if (c == EOF)
+      break;
+    do {
+      *p++ = c;
+    } while (c != '\n' && (c = fgetc (stream)) >= 0);
+
+    /* we now have a source line in buf, null terminate and match */
+    *p = 0;
+    if (re_exec (buf) > 0)
+      {
+	/* Match! */
+	fclose (stream);
+	print_source_lines (current_source_symtab,
+			   line, line+1, 0);
+	current_source_line = max (line - lines_to_list () / 2, 1);
+	return;
+      }
+    line++;
+  }
+
+  printf ("Expression not found\n");
+  fclose (stream);
+}
+
+static void
+reverse_search_command (regex, from_tty)
+     char *regex;
+     int from_tty;
+{
+  register int c;
+  register int desc;
+  register FILE *stream;
+  int line = last_line_listed - 1;
+  char *msg;
+
+  msg = (char *) re_comp (regex);
+  if (msg)
+    error (msg);
+
+  if (current_source_symtab == 0)
+    select_source_symtab (0);
+
+  /* Search from last_line_listed-1 in current_source_symtab */
+
+  desc = open_source_file (current_source_symtab);
+  if (desc < 0)
+    perror_with_name (current_source_symtab->filename);
+
+  if (current_source_symtab->line_charpos == 0)
+    find_source_lines (current_source_symtab, desc);
+
+  if (line < 1 || line > current_source_symtab->nlines)
+    {
+      close (desc);
+      error ("Expression not found");
+    }
+
+  if (lseek (desc, current_source_symtab->line_charpos[line - 1], 0) < 0)
+    {
+      close (desc);
+      perror_with_name (current_source_symtab->filename);
+    }
+
+  stream = fdopen (desc, "r");
+  clearerr (stream);
+  while (line > 1)
+    {
+      char buf[4096];		/* Should be reasonable??? */
+      register char *p = buf;
+
+      c = fgetc (stream);
+      if (c == EOF)
+	break;
+      do {
+	*p++ = c;
+      } while (c != '\n' && (c = fgetc (stream)) >= 0);
+
+      /* We now have a source line in buf; null terminate and match.  */
+      *p = 0;
+      if (re_exec (buf) > 0)
+	{
+	  /* Match! */
+	  fclose (stream);
+	  print_source_lines (current_source_symtab,
+			      line, line+1, 0);
+	  current_source_line = max (line - lines_to_list () / 2, 1);
+	  return;
+	}
+      line--;
+      if (fseek (stream, current_source_symtab->line_charpos[line - 1], 0) < 0)
+	{
+	  fclose (stream);
+	  perror_with_name (current_source_symtab->filename);
+	}
+    }
+
+  printf ("Expression not found\n");
+  fclose (stream);
+  return;
+}
+
+void
+_initialize_source ()
+{
+  current_source_symtab = 0;
+  init_source_path ();
+
+  add_com ("directory", class_files, directory_command,
+	   "Add directory DIR to beginning of search path for source files.\n\
+Forget cached info on source file locations and line positions.\n\
+DIR can also be $cwd for the current working directory, or $cdir for the\n\
+directory in which the source file was compiled into object code.\n\
+With no argument, reset the search path to $cdir:$cwd, the default.");
+
+  add_info ("directories", directories_info,
+	    "Current search path for finding source files.\n\
+$cwd in the path means the current working directory.\n\
+$cdir in the path means the compilation directory of the source file.");
+
+  add_info ("source", source_info,
+	    "Information about the current source file.");
+
+  add_info ("line", line_info,
+	    "Core addresses of the code for a source line.\n\
+Line can be specified as\n\
+  LINENUM, to list around that line in current file,\n\
+  FILE:LINENUM, to list around that line in that file,\n\
+  FUNCTION, to list around beginning of that function,\n\
+  FILE:FUNCTION, to distinguish among like-named static functions.\n\
+Default is to describe the last source line that was listed.\n\n\
+This sets the default address for \"x\" to the line's first instruction\n\
+so that \"x/i\" suffices to start examining the machine code.\n\
+The address is also stored as the value of \"$_\".");
+
+  add_com ("forward-search", class_files, forward_search_command,
+	   "Search for regular expression (see regex(3)) from last line listed.");
+  add_com_alias ("search", "forward-search", class_files, 0);
+
+  add_com ("reverse-search", class_files, reverse_search_command,
+	   "Search backward for regular expression (see regex(3)) from last line listed.");
+
+  add_com ("list", class_files, list_command,
+	   "List specified function or line.\n\
+With no argument, lists ten more lines after or around previous listing.\n\
+\"list -\" lists the ten lines before a previous ten-line listing.\n\
+One argument specifies a line, and ten lines are listed around that line.\n\
+Two arguments with comma between specify starting and ending lines to list.\n\
+Lines can be specified in these ways:\n\
+  LINENUM, to list around that line in current file,\n\
+  FILE:LINENUM, to list around that line in that file,\n\
+  FUNCTION, to list around beginning of that function,\n\
+  FILE:FUNCTION, to distinguish among like-named static functions.\n\
+  *ADDRESS, to list around the line containing that address.\n\
+With two args if one is empty it stands for ten lines away from the other arg.");
+  add_com_alias ("l", "list", class_files, 0);
+}
+