Detect the absence of a symbol hash table.

[deliverable/binutils-gdb.git] / gdb / rs6000-nat.c

diff --git a/gdb/rs6000-nat.c b/gdb/rs6000-nat.c
index 73110558664bb095e56563f76f17203296d62dd3..7e250ef1aa46ef59df0318dd2b8e4926c8f433e7 100644 (file)
--- a/gdb/rs6000-nat.c
+++ b/gdb/rs6000-nat.c
@@ -1,5 +1,5 @@
 /* IBM RS/6000 native-dependent code for GDB, the GNU debugger.
-   Copyright 1986, 1987, 1989, 1991, 1992, 1994, 1995, 1996, 1997
+   Copyright 1986, 1987, 1989, 1991, 1992, 1994, 1995, 1996, 1997, 1998
             Free Software Foundation, Inc.
 
 This file is part of GDB.
@@ -72,9 +72,6 @@ fetch_core_registers PARAMS ((char *, unsigned int, int, CORE_ADDR));
 static void
 exec_one_dummy_insn PARAMS ((void));
 
-extern void
-add_text_to_loadinfo PARAMS ((CORE_ADDR textaddr, CORE_ADDR dataaddr));
-
 extern void
 fixup_breakpoints PARAMS ((CORE_ADDR low, CORE_ADDR high, CORE_ADDR delta));
 
@@ -248,7 +245,7 @@ exec_one_dummy_insn ()
 #define        DUMMY_INSN_ADDR (TEXT_SEGMENT_BASE)+0x200
 
   char shadow_contents[BREAKPOINT_MAX];        /* Stash old bkpt addr contents */
-  unsigned int status, pid;
+  int status, pid;
   CORE_ADDR prev_pc;
 
   /* We plant one dummy breakpoint into DUMMY_INSN_ADDR address. We assume that
@@ -469,15 +466,24 @@ vmap_ldinfo (ldi)
     retried = 0;
 
     if (fstat (ldi->ldinfo_fd, &ii) < 0)
-      fatal ("cannot fstat(fd=%d) on %s", ldi->ldinfo_fd, name);
+      {
+       /* The kernel sets ld_info to -1, if the process is still using the
+          object, and the object is removed. Keep the symbol info for the
+          removed object and issue a warning.  */
+       warning ("%s (fd=%d) has disappeared, keeping its symbols",
+                name, ldi->ldinfo_fd);
+        continue;
+      }
   retry:
     for (got_one = 0, vp = vmap; vp; vp = vp->nxt)
       {
+       struct objfile *objfile;
+
        /* First try to find a `vp', which is the same as in ldinfo.
           If not the same, just continue and grep the next `vp'. If same,
           relocate its tstart, tend, dstart, dend values. If no such `vp'
           found, get out of this for loop, add this ldi entry as a new vmap
-          (add_vmap) and come back, fins its `vp' and so on... */
+          (add_vmap) and come back, find its `vp' and so on... */
 
        /* The filenames are not always sufficient to match on. */
 
@@ -485,15 +491,17 @@ vmap_ldinfo (ldi)
            || (memb[0] && !STREQ(memb, vp->member)))
          continue;
 
-       /* See if we are referring to the same file. */
-       if (bfd_stat (vp->bfd, &vi) < 0)
-         /* An error here is innocuous, most likely meaning that
-            the file descriptor has become worthless.
-            FIXME: What does it mean for a file descriptor to become
-            "worthless"?  What makes it happen?  What error does it
-            produce (ENOENT? others?)?  Should we at least provide
-            a warning?  */
-         continue;
+       /* See if we are referring to the same file.
+          We have to check objfile->obfd, symfile.c:reread_symbols might
+          have updated the obfd after a change.  */
+       objfile = vp->objfile == NULL ? symfile_objfile : vp->objfile;
+       if (objfile == NULL
+           || objfile->obfd == NULL
+           || bfd_stat (objfile->obfd, &vi) < 0)
+         {
+           warning ("Unable to stat %s, keeping its symbols", name);
+           continue;
+         }
 
        if (ii.st_dev != vi.st_dev || ii.st_ino != vi.st_ino)
          continue;
@@ -623,25 +631,12 @@ xcoff_relocate_symtab (pid)
 
   errno = 0;
   ptrace (PT_LDINFO, pid, (PTRACE_ARG3_TYPE) ldi,
-         MAX_LOAD_SEGS * sizeof(*ldi), ldi);
+         MAX_LOAD_SEGS * sizeof(*ldi), (int *) ldi);
   if (errno)
     perror_with_name ("ptrace ldinfo");
 
   vmap_ldinfo (ldi);
 
-  do {
-    /* We are allowed to assume CORE_ADDR == pointer.  This code is
-       native only.  */
-    add_text_to_loadinfo ((CORE_ADDR) ldi->ldinfo_textorg,
-                         (CORE_ADDR) ldi->ldinfo_dataorg);
-  } while (ldi->ldinfo_next
-          && (ldi = (void *) (ldi->ldinfo_next + (char *) ldi)));
-
-#if 0
-  /* Now that we've jumbled things around, re-sort them.  */
-  sort_minimal_symbols ();
-#endif
-
   /* relocate the exec and core sections as well. */
   vmap_exec ();
 }
@@ -780,9 +775,6 @@ xcoff_relocate_core (target)
        }
 
       vmap_symtab (vp);
-
-      add_text_to_loadinfo ((CORE_ADDR)ldip->ldinfo_textorg,
-                           (CORE_ADDR)ldip->ldinfo_dataorg);
     } while (ldip->ldinfo_next != 0);
   vmap_exec ();
   breakpoint_re_set ();
@@ -794,7 +786,30 @@ kernel_u_size ()
 {
   return (sizeof (struct user));
 }
+\f
+/* Under AIX, we have to pass the correct TOC pointer to a function
+   when calling functions in the inferior.
+   We try to find the relative toc offset of the objfile containing PC
+   and add the current load address of the data segment from the vmap.  */
+
+static CORE_ADDR
+find_toc_address (pc)
+     CORE_ADDR pc;
+{
+  struct vmap *vp;
 
+  for (vp = vmap; vp; vp = vp->nxt)
+    {
+      if (pc >= vp->tstart && pc < vp->tend)
+       {
+         /* vp->objfile is only NULL for the exec file.  */
+         return vp->dstart + get_toc_offset (vp->objfile == NULL
+                                             ? symfile_objfile
+                                             : vp->objfile);
+       }
+    }
+  error ("Unable to find TOC entry for pc 0x%x\n", pc);
+}
 \f
 /* Register that we are able to handle rs6000 core file formats. */
 
@@ -808,6 +823,10 @@ static struct core_fns rs6000_core_fns =
 void
 _initialize_core_rs6000 ()
 {
+  /* Initialize hook in rs6000-tdep.c for determining the TOC address when
+     calling functions in the inferior.  */
+  find_toc_address_hook = &find_toc_address;
+
   /* For native configurations, where this module is included, inform
      the xcoffsolib module where it can find the function for symbol table
      relocation at runtime. */