Make various lm_info implementations inherit from a base class

The lm_info structure is used to store target specific information about
mapped libraries.  It is currently defined as an opaque type in solist.h
and a pointer to it is included in solist, the target-agnostic object
representing a loaded shared library.  Multiple targets define their own
implementation of lm_info.

In anticipation of using C++ stuff (e.g. vector) in the lm_info objects,
we first need to avoid different definitions of classes with the same
name (which violates the one definition rule).  This patch does it by
having a base class (lm_info_base) from which all the specific lm_info
derive.  Each implementation is renamed to something that makes sense
(e.g. lm_info_aix for AIX).  The next logical step would probably be to
derive directly from so_list, it's not really obvious, so I'll keep that
for another day.

One special case is the Neutrino (nto) support.  It uses SVR4-style
libraries, but overrides some methods.  To do that, it needed to have
its own copy of SVR4's lm_info structure in nto-tdep.c, because it was
just not possible to put it in solib-svr4.h and include that file.  Over
time, that copy got out of sync, which is still the case today.  I can
only assume that the lm_addr function in nto-tdep.c is broken right now.
The first field of the old lm_info was a pointer (gdb_byte *), whereas
in the new lm_info it's an address in the inferior (CORE_ADDR).  Trying
to use that field today probably results in a crash.  With this
refactor, it's now possible to put lm_info_svr4 in solib-svr4.h and just
include it.  I have adapted the code in nto-tdep.c to that it builds,
but it's probably not correct.  Since I don't have the knowledge nor
setup to try this on Neutrino, somebody else would have to fix it.  But
I am confident that I am not making things worse than they already are.

gdb/ChangeLog:

	* solist.h (struct lm_info): Remove.
	(struct lm_info_base): New class.
	(struct so_list) <lm_info>: Change type to lm_info_base *.
	* nto-tdep.c (struct lm_info): Remove.
	(lm_addr): Adjust.
	* solib-aix.c (struct lm_info): Rename to ...
	(struct lm_info_aix): ... this.  Extend lm_info_base.
	(lm_info_p): Rename to ...
	(lm_info_aix_p): ... this, and adjust.
	(solib_aix_new_lm_info, solib_aix_xfree_lm_info,
	solib_aix_parse_libraries, library_list_start_library,
	solib_aix_free_library_list, solib_aix_parse_libraries,
	solib_aix_get_library_list,
	solib_aix_relocate_section_addresses, solib_aix_free_so,
	solib_aix_get_section_offsets,
	solib_aix_solib_create_inferior_hook, solib_aix_current_sos):
	Adjust.
	(struct solib_aix_inferior_data) <library_list>: Adjust.
	* solib-darwin.c (struct lm_info): Rename to ...
	(struct lm_info_darwin): ... this.  Extend lm_info_base.
	(darwin_current_sos, darwin_relocate_section_addresses): Adjust.
	* solib-dsbt.c (struct lm_info): Rename to ...
	(struct lm_info_dsbt): ... this.  Extend lm_info_base.
	(struct dsbt_info) <main_executable_lm_info): Adjust.
	(dsbt_current_sos, dsbt_relocate_main_executable, dsbt_free_so,
	dsbt_relocate_section_addresses): Adjust.
	* solib-frv.c (struct lm_info): Rename to ...
	(struct lm_info_frv): ... this.  Extend lm_info_base.
	(main_executable_lm_info): Adjust.
	(frv_current_sos, frv_relocate_main_executable, frv_free_so,
	frv_relocate_section_addresses, frv_fdpic_find_global_pointer,
	find_canonical_descriptor_in_load_object,
	frv_fdpic_find_canonical_descriptor): Adjust.
	* solib-svr4.c (struct lm_info): Move to solib-svr4.h, renamed
	to lm_info_svr4.
	(lm_info_read, lm_addr_check, svr4_keep_data_in_core,
	svr4_clear_so, svr4_copy_library_list,
	library_list_start_library, svr4_default_sos, svr4_read_so_list,
	svr4_current_sos, svr4_fetch_objfile_link_map,
	solist_update_incremental): Adjust.
	* solib-svr4.h (struct lm_info_svr4): Move here from
	solib-svr4.c.
	* solib-target.c (struct lm_info): Rename to ...
	(struct lm_info_target): ... this.  Extend lm_info_base.
	(lm_info_p): Rename to ...
	(lm_info_target_p): ... this.
	(solib_target_parse_libraries, library_list_start_segment,
	library_list_start_section, library_list_start_library,
	library_list_end_library, solib_target_free_library_list,
	solib_target_current_sos, solib_target_free_so,
	solib_target_relocate_section_addresses): Adjust.
	* windows-nat.c (struct lm_info): Rename to ...
	(struct lm_info_windows): ... this.  Extend lm_info_base.
	(windows_make_so, handle_load_dll, handle_unload_dll,
	windows_xfer_shared_libraries): Adjust.

1 files changed, 53 insertions, 58 deletions

diff --git a/gdb/solib-svr4.c b/gdb/solib-svr4.c
index 4cb6127..6098d50 100644
--- a/gdb/solib-svr4.c
+++ b/gdb/solib-svr4.c
@@ -51,27 +51,6 @@ static int svr4_have_link_map_offsets (void);
 static void svr4_relocate_main_executable (void);
 static void svr4_free_library_list (void *p_list);
 
-/* Link map info to include in an allocated so_list entry.  */
-
-struct lm_info
-  {
-    /* Amount by which addresses in the binary should be relocated to
-       match the inferior.  The direct inferior value is L_ADDR_INFERIOR.
-       When prelinking is involved and the prelink base address changes,
-       we may need a different offset - the recomputed offset is in L_ADDR.
-       It is commonly the same value.  It is cached as we want to warn about
-       the difference and compute it only once.  L_ADDR is valid
-       iff L_ADDR_P.  */
-    CORE_ADDR l_addr, l_addr_inferior;
-    unsigned int l_addr_p : 1;
-
-    /* The target location of lm.  */
-    CORE_ADDR lm_addr;
-
-    /* Values read in from inferior's fields of the same name.  */
-    CORE_ADDR l_ld, l_next, l_prev, l_name;
-  };
-
 /* On SVR4 systems, a list of symbols in the dynamic linker where
    GDB can try to place a breakpoint to monitor shared library
    events.
@@ -189,12 +168,12 @@ svr4_same (struct so_list *gdb, struct so_list *inferior)
   return (svr4_same_1 (gdb->so_original_name, inferior->so_original_name));
 }
 
-static struct lm_info *
+static lm_info_svr4 *
 lm_info_read (CORE_ADDR lm_addr)
 {
   struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
   gdb_byte *lm;
-  struct lm_info *lm_info;
+  lm_info_svr4 *lm_info;
   struct cleanup *back_to;
 
   lm = (gdb_byte *) xmalloc (lmo->link_map_size);
@@ -210,7 +189,7 @@ lm_info_read (CORE_ADDR lm_addr)
     {
       struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
 
-      lm_info = XCNEW (struct lm_info);
+      lm_info = XCNEW (lm_info_svr4);
       lm_info->lm_addr = lm_addr;
 
       lm_info->l_addr_inferior = extract_typed_address (&lm[lmo->l_addr_offset],
@@ -240,17 +219,19 @@ has_lm_dynamic_from_link_map (void)
 static CORE_ADDR
 lm_addr_check (const struct so_list *so, bfd *abfd)
 {
-  if (!so->lm_info->l_addr_p)
+  lm_info_svr4 *li = (lm_info_svr4 *) so->lm_info;
+
+  if (!li->l_addr_p)
     {
       struct bfd_section *dyninfo_sect;
       CORE_ADDR l_addr, l_dynaddr, dynaddr;
 
-      l_addr = so->lm_info->l_addr_inferior;
+      l_addr = li->l_addr_inferior;
 
       if (! abfd || ! has_lm_dynamic_from_link_map ())
 	goto set_addr;
 
-      l_dynaddr = so->lm_info->l_ld;
+      l_dynaddr = li->l_ld;
 
       dyninfo_sect = bfd_get_section_by_name (abfd, ".dynamic");
       if (dyninfo_sect == NULL)
@@ -333,11 +314,11 @@ lm_addr_check (const struct so_list *so, bfd *abfd)
 	}
 
     set_addr:
-      so->lm_info->l_addr = l_addr;
-      so->lm_info->l_addr_p = 1;
+      li->l_addr = l_addr;
+      li->l_addr_p = 1;
     }
 
-  return so->lm_info->l_addr;
+  return li->l_addr;
 }
 
 /* Per pspace SVR4 specific data.  */
@@ -994,9 +975,10 @@ svr4_keep_data_in_core (CORE_ADDR vaddr, unsigned long size)
 
   newobj = XCNEW (struct so_list);
   old_chain = make_cleanup (xfree, newobj);
-  newobj->lm_info = lm_info_read (ldsomap);
+  lm_info_svr4 *li = lm_info_read (ldsomap);
+  newobj->lm_info = li;
   make_cleanup (xfree, newobj->lm_info);
-  name_lm = newobj->lm_info ? newobj->lm_info->l_name : 0;
+  name_lm = li != NULL ? li->l_name : 0;
   do_cleanups (old_chain);
 
   return (name_lm >= vaddr && name_lm < vaddr + size);
@@ -1106,8 +1088,10 @@ svr4_free_so (struct so_list *so)
 static void
 svr4_clear_so (struct so_list *so)
 {
-  if (so->lm_info != NULL)
-    so->lm_info->l_addr_p = 0;
+  lm_info_svr4 *li = (lm_info_svr4 *) so->lm_info;
+
+  if (li != NULL)
+    li->l_addr_p = 0;
 }
 
 /* Free so_list built so far (called via cleanup).  */
@@ -1141,8 +1125,8 @@ svr4_copy_library_list (struct so_list *src)
       newobj = XNEW (struct so_list);
       memcpy (newobj, src, sizeof (struct so_list));
 
-      newobj->lm_info = XNEW (struct lm_info);
-      memcpy (newobj->lm_info, src->lm_info, sizeof (struct lm_info));
+      newobj->lm_info = XNEW (lm_info_svr4);
+      memcpy (newobj->lm_info, src->lm_info, sizeof (lm_info_svr4));
 
       newobj->next = NULL;
       *link = newobj;
@@ -1178,10 +1162,11 @@ library_list_start_library (struct gdb_xml_parser *parser,
   struct so_list *new_elem;
 
   new_elem = XCNEW (struct so_list);
-  new_elem->lm_info = XCNEW (struct lm_info);
-  new_elem->lm_info->lm_addr = *lmp;
-  new_elem->lm_info->l_addr_inferior = *l_addrp;
-  new_elem->lm_info->l_ld = *l_ldp;
+  lm_info_svr4 *li = XCNEW (lm_info_svr4);
+  new_elem->lm_info = li;
+  li->lm_addr = *lmp;
+  li->l_addr_inferior = *l_addrp;
+  li->l_ld = *l_ldp;
 
   strncpy (new_elem->so_name, name, sizeof (new_elem->so_name) - 1);
   new_elem->so_name[sizeof (new_elem->so_name) - 1] = 0;
@@ -1332,12 +1317,12 @@ svr4_default_sos (void)
     return NULL;
 
   newobj = XCNEW (struct so_list);
-
-  newobj->lm_info = XCNEW (struct lm_info);
+  lm_info_svr4 *li = XCNEW (lm_info_svr4);
+  newobj->lm_info = li;
 
   /* Nothing will ever check the other fields if we set l_addr_p.  */
-  newobj->lm_info->l_addr = info->debug_loader_offset;
-  newobj->lm_info->l_addr_p = 1;
+  li->l_addr = info->debug_loader_offset;
+  li->l_addr_p = 1;
 
   strncpy (newobj->so_name, info->debug_loader_name, SO_NAME_MAX_PATH_SIZE - 1);
   newobj->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
@@ -1371,20 +1356,21 @@ svr4_read_so_list (CORE_ADDR lm, CORE_ADDR prev_lm,
       newobj = XCNEW (struct so_list);
       old_chain = make_cleanup_free_so (newobj);
 
-      newobj->lm_info = lm_info_read (lm);
-      if (newobj->lm_info == NULL)
+      lm_info_svr4 *li = lm_info_read (lm);
+      newobj->lm_info = li;
+      if (li == NULL)
 	{
 	  do_cleanups (old_chain);
 	  return 0;
 	}
 
-      next_lm = newobj->lm_info->l_next;
+      next_lm = li->l_next;
 
-      if (newobj->lm_info->l_prev != prev_lm)
+      if (li->l_prev != prev_lm)
 	{
 	  warning (_("Corrupted shared library list: %s != %s"),
 		   paddress (target_gdbarch (), prev_lm),
-		   paddress (target_gdbarch (), newobj->lm_info->l_prev));
+		   paddress (target_gdbarch (), li->l_prev));
 	  do_cleanups (old_chain);
 	  return 0;
 	}
@@ -1394,26 +1380,26 @@ svr4_read_so_list (CORE_ADDR lm, CORE_ADDR prev_lm,
          SVR4, it has no name.  For others (Solaris 2.3 for example), it
          does have a name, so we can no longer use a missing name to
          decide when to ignore it.  */
-      if (ignore_first && newobj->lm_info->l_prev == 0)
+      if (ignore_first && li->l_prev == 0)
 	{
 	  struct svr4_info *info = get_svr4_info ();
 
-	  first_l_name = newobj->lm_info->l_name;
-	  info->main_lm_addr = newobj->lm_info->lm_addr;
+	  first_l_name = li->l_name;
+	  info->main_lm_addr = li->lm_addr;
 	  do_cleanups (old_chain);
 	  continue;
 	}
 
       /* Extract this shared object's name.  */
-      target_read_string (newobj->lm_info->l_name, &buffer,
-			  SO_NAME_MAX_PATH_SIZE - 1, &errcode);
+      target_read_string (li->l_name, &buffer, SO_NAME_MAX_PATH_SIZE - 1,
+			  &errcode);
       if (errcode != 0)
 	{
 	  /* If this entry's l_name address matches that of the
 	     inferior executable, then this is not a normal shared
 	     object, but (most likely) a vDSO.  In this case, silently
 	     skip it; otherwise emit a warning. */
-	  if (first_l_name == 0 || newobj->lm_info->l_name != first_l_name)
+	  if (first_l_name == 0 || li->l_name != first_l_name)
 	    warning (_("Can't read pathname for load map: %s."),
 		     safe_strerror (errcode));
 	  do_cleanups (old_chain);
@@ -1594,7 +1580,10 @@ svr4_current_sos (void)
 	      [...]
 		[ 9] .dynamic DYNAMIC ffffffffff700580 000580 0000f0
 	  */
-	  if (address_in_mem_range (so->lm_info->l_ld, &vsyscall_range))
+
+	  lm_info_svr4 *li = (lm_info_svr4 *) so->lm_info;
+
+	  if (address_in_mem_range (li->l_ld, &vsyscall_range))
 	    {
 	      *sop = so->next;
 	      free_so (so);
@@ -1628,7 +1617,11 @@ svr4_fetch_objfile_link_map (struct objfile *objfile)
      of shared libraries.  */
   for (so = master_so_list (); so; so = so->next)
     if (so->objfile == objfile)
-      return so->lm_info->lm_addr;
+      {
+	lm_info_svr4 *li = (lm_info_svr4 *) so->lm_info;
+
+	return li->lm_addr;
+      }
 
   /* Not found!  */
   return 0;
@@ -1860,7 +1853,9 @@ solist_update_incremental (struct svr4_info *info, CORE_ADDR lm)
   /* Walk to the end of the list.  */
   for (tail = info->solib_list; tail->next != NULL; tail = tail->next)
     /* Nothing.  */;
-  prev_lm = tail->lm_info->lm_addr;
+
+  lm_info_svr4 *li = (lm_info_svr4 *) tail->lm_info;
+  prev_lm = li->lm_addr;
 
   /* Read the new objects.  */
   if (info->using_xfer)