* dbxread.c (end_psymtab): Add comment about empty psymtabs.
authorJim Kingdon <jkingdon@engr.sgi.com>
Thu, 24 Mar 1994 15:12:40 +0000 (15:12 +0000)
committerJim Kingdon <jkingdon@engr.sgi.com>
Thu, 24 Mar 1994 15:12:40 +0000 (15:12 +0000)
gdb/ChangeLog
gdb/dbxread.c

index df51834..25772ba 100644 (file)
@@ -1,3 +1,7 @@
+Thu Mar 24 07:12:09 1994  Jim Kingdon  (kingdon@lioth.cygnus.com)
+
+       * dbxread.c (end_psymtab): Add comment about empty psymtabs.
+
 Wed Mar 23 07:50:33 1994  Jim Kingdon  (kingdon@lioth.cygnus.com)
 
        * main.c (complete_command): New command, from Rick Sladkey
index 02441f2..92f59d7 100644 (file)
@@ -206,6 +206,10 @@ static void
 dbx_psymtab_to_symtab_1 PARAMS ((struct partial_symtab *));
 
 static void
+read_dbx_dynamic_symtab PARAMS ((struct section_offsets *,
+                                struct objfile *objfile));
+
+static void
 read_dbx_symtab PARAMS ((struct section_offsets *, struct objfile *,
                         CORE_ADDR, int));
 
@@ -509,6 +513,11 @@ dbx_symfile_read (objfile, section_offsets, mainline)
                   bfd_section_vma  (sym_bfd, DBX_TEXT_SECT (objfile)),
                   bfd_section_size (sym_bfd, DBX_TEXT_SECT (objfile)));
 
+  /* Add the dynamic symbols if we are reading the main symbol table.  */
+
+  if (mainline)
+    read_dbx_dynamic_symtab (section_offsets, objfile);
+
   /* Install any minimal symbols that have been collected as the current
      minimal symbols for this objfile. */
 
@@ -825,6 +834,169 @@ free_bincl_list (objfile)
   bincls_allocated = 0;
 }
 
+/* Scan a SunOs dynamic symbol table for symbols of interest and
+   add them to the minimal symbol table.  */
+
+static void
+read_dbx_dynamic_symtab (section_offsets, objfile)
+     struct section_offsets *section_offsets;
+     struct objfile *objfile;
+{
+  bfd *abfd = objfile->obfd;
+  int counter;
+  bfd_size_type dynsym_count = 0;
+  struct external_nlist *dynsyms = NULL;
+  char *dynstrs = NULL;
+  bfd_size_type dynstr_size;
+  struct external_nlist *ext_symptr;
+  bfd_byte *ext_relptr;
+  bfd_size_type dynrel_count = 0;
+  PTR dynrels = NULL;
+  CORE_ADDR sym_value;
+  bfd_vma strx;
+  char *namestring;
+
+  /* Check that the symbol file has dynamic symbols that we know about.
+     bfd_arch_unknown can happen if we are reading a sun3 symbol file
+     on a sun4 host (and vice versa) and bfd is not configured
+     --with-target=all.  This would trigger an assertion in bfd/sunos.c,
+     so we ignore the dynamic symbols in this case.  */
+  if (bfd_get_flavour (abfd) != bfd_target_aout_flavour
+      || (bfd_get_file_flags (abfd) & DYNAMIC) == 0
+      || bfd_get_arch (abfd) == bfd_arch_unknown
+      || aout_backend_info (abfd)->read_dynamic_symbols == NULL)
+    return;
+
+  dynsym_count = ((*aout_backend_info (abfd)->read_dynamic_symbols)
+                 (abfd, &dynsyms, &dynstrs, &dynstr_size));
+  if (dynsym_count == (bfd_size_type) -1)
+    return;
+
+  /* Enter dynamic symbols into the minimal symbol table
+     if this is a stripped executable.  */
+  if (bfd_get_symcount (abfd) <= 0)
+    {
+      ext_symptr = dynsyms;
+      for (counter = 0; counter < dynsym_count; counter++, ext_symptr++)
+       {
+         int type = bfd_h_get_8 (abfd, ext_symptr->e_type);
+
+         switch (type)
+           {
+           case N_TEXT | N_EXT:
+             sym_value = bfd_h_get_32 (abfd, ext_symptr->e_value)
+                         + ANOFFSET (section_offsets, SECT_OFF_TEXT);
+             break;
+
+           case N_DATA:
+           case N_DATA | N_EXT:
+             sym_value = bfd_h_get_32 (abfd, ext_symptr->e_value)
+                         + ANOFFSET (section_offsets, SECT_OFF_DATA);
+             break;
+
+           case N_BSS:
+           case N_BSS | N_EXT:
+             sym_value = bfd_h_get_32 (abfd, ext_symptr->e_value)
+                         + ANOFFSET (section_offsets, SECT_OFF_BSS);
+             break;
+
+           default:
+             continue;
+           }
+
+         strx = bfd_h_get_32 (abfd, ext_symptr->e_strx);
+         if (strx >= dynstr_size)
+           {
+             complain (&string_table_offset_complaint, counter);
+             namestring = "<bad dynamic string table offset>";
+           }
+         else
+           namestring = strx + dynstrs;
+         record_minimal_symbol (namestring, sym_value, type, objfile);
+       }
+    }
+
+  /* Symbols from shared libraries have a dynamic relocation entry
+     that points to the associated slot in the procedure linkage table.
+     We make a mininal symbol table entry with type mst_solib_trampoline
+     at the address in the procedure linkage table.  */
+  if (aout_backend_info (abfd)->read_dynamic_relocs == NULL)
+    return;
+
+  dynrel_count = ((*aout_backend_info (abfd)->read_dynamic_relocs)
+                 (abfd, &dynrels));
+  if (dynrel_count == (bfd_size_type) -1)
+    return;
+
+  for (counter = 0, ext_relptr = (bfd_byte *) dynrels;
+       counter < dynrel_count;
+       counter++, ext_relptr += obj_reloc_entry_size (abfd))
+    {
+      int r_index;
+
+      if (bfd_get_arch (abfd) == bfd_arch_sparc)
+       {
+         struct reloc_ext_external *rptr =
+           (struct reloc_ext_external *) ext_relptr;
+         int r_type;
+
+         r_type = (rptr->r_type[0] & RELOC_EXT_BITS_TYPE_BIG)
+                   >> RELOC_EXT_BITS_TYPE_SH_BIG;
+
+         if (r_type != RELOC_JMP_SLOT)
+           continue;
+
+         r_index = (rptr->r_index[0] << 16)
+                   | (rptr->r_index[1] << 8)
+                   | rptr->r_index[2];
+
+         sym_value = bfd_h_get_32 (abfd, rptr->r_address);
+       }
+      else if (bfd_get_arch (abfd) == bfd_arch_m68k)
+       {
+         struct reloc_std_external *rptr =
+           (struct reloc_std_external *) ext_relptr;
+
+         if ((rptr->r_type[0] & RELOC_STD_BITS_JMPTABLE_BIG) == 0)
+           continue;
+
+         r_index = (rptr->r_index[0] << 16)
+                   | (rptr->r_index[1] << 8)
+                   | rptr->r_index[2];
+
+         /* Adjust address in procedure linkage table to point to
+            the start of the bsr instruction.  */
+         sym_value = bfd_h_get_32 (abfd, rptr->r_address) - 2;
+       }
+      else
+       {
+         continue;
+       }
+
+      if (r_index >= dynsym_count)
+       continue;
+      ext_symptr = dynsyms + r_index;
+      if (bfd_h_get_8 (abfd, ext_symptr->e_type) != N_EXT)
+       continue;
+
+      strx = bfd_h_get_32 (abfd, ext_symptr->e_strx);
+      if (strx >= dynstr_size)
+       {
+         complain (&string_table_offset_complaint, r_index);
+         namestring = "<bad dynamic string table offset>";
+       }
+      else
+       namestring = strx + dynstrs;
+
+      prim_record_minimal_symbol (obsavestring (namestring,
+                                               strlen (namestring),
+                                               &objfile -> symbol_obstack),
+                                 sym_value,
+                                 mst_solib_trampoline,
+                                 objfile);
+    }
+}
+
 /* Given pointers to an a.out symbol table in core containing dbx
    style data, setup partial_symtab's describing each source file for
    which debugging information is available.
@@ -931,7 +1103,7 @@ read_dbx_symtab (section_offsets, objfile, text_addr, text_size)
   if (((unsigned)bufp->n_strx + file_string_table_offset) >=           \
       DBX_STRINGTAB_SIZE (objfile)) {                                  \
     complain (&string_table_offset_complaint, symnum);                 \
-    namestring = "foo";                                                        \
+    namestring = "<bad string table offset>";                          \
   } else                                                               \
     namestring = bufp->n_strx + file_string_table_offset +             \
                 DBX_STRINGTAB (objfile)
@@ -1187,30 +1359,36 @@ end_psymtab (pst, include_list, num_includes, capping_symbol_offset,
   free_named_symtabs (pst->filename);
 
   if (num_includes == 0
-   && number_dependencies == 0
-   && pst->n_global_syms == 0
-   && pst->n_static_syms == 0) {
-    /* Throw away this psymtab, it's empty.  We can't deallocate it, since
-       it is on the obstack, but we can forget to chain it on the list.  */
-    struct partial_symtab *prev_pst;
-
-    /* First, snip it out of the psymtab chain */
-
-    if (pst->objfile->psymtabs == pst)
-      pst->objfile->psymtabs = pst->next;
-    else
-      for (prev_pst = pst->objfile->psymtabs; prev_pst; prev_pst = pst->next)
-       if (prev_pst->next == pst)
-         prev_pst->next = pst->next;
+      && number_dependencies == 0
+      && pst->n_global_syms == 0
+      && pst->n_static_syms == 0)
+    {
+      /* Throw away this psymtab, it's empty.  We can't deallocate it, since
+        it is on the obstack, but we can forget to chain it on the list.  */
+      /* Empty psymtabs happen as a result of header files which don't have
+        any symbols in them.  There can be a lot of them.  But this check
+        is wrong, in that a psymtab with N_SLINE entries but nothing else
+        is not empty, but we don't realize that.  Fixing that without slowing
+        things down might be tricky.  */
+      struct partial_symtab *prev_pst;
+
+      /* First, snip it out of the psymtab chain */
+
+      if (pst->objfile->psymtabs == pst)
+       pst->objfile->psymtabs = pst->next;
+      else
+       for (prev_pst = pst->objfile->psymtabs; prev_pst; prev_pst = pst->next)
+         if (prev_pst->next == pst)
+           prev_pst->next = pst->next;
 
-    /* Next, put it on a free list for recycling */
+      /* Next, put it on a free list for recycling */
 
-    pst->next = pst->objfile->free_psymtabs;
-    pst->objfile->free_psymtabs = pst;
+      pst->next = pst->objfile->free_psymtabs;
+      pst->objfile->free_psymtabs = pst;
 
-    /* Indicate that psymtab was thrown away.  */
-    pst = (struct partial_symtab *)NULL;
-  }
+      /* Indicate that psymtab was thrown away.  */
+      pst = (struct partial_symtab *)NULL;
+    }
   return pst;
 }
 \f