From d0e449a1865c741c5e0c9d43a7d61a0621163aa7 Mon Sep 17 00:00:00 2001
From: Simon Marchi <simon.marchi@ericsson.com>
Date: Fri, 28 Apr 2017 17:16:13 -0400
Subject: 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.
---
 gdb/solib-dsbt.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

(limited to 'gdb/solib-dsbt.c')

diff --git a/gdb/solib-dsbt.c b/gdb/solib-dsbt.c
index c407106..6d410ac 100644
--- a/gdb/solib-dsbt.c
+++ b/gdb/solib-dsbt.c
@@ -123,7 +123,7 @@ struct ext_link_map
 
 /* Link map info to include in an allocated so_list entry */
 
-struct lm_info
+struct lm_info_dsbt : public lm_info_base
 {
   /* The loadmap, digested into an easier to use form.  */
   struct int_elf32_dsbt_loadmap *map;
@@ -137,7 +137,7 @@ struct dsbt_info
      of loaded shared objects.  ``main_executable_lm_info'' provides
      a way to get at this information so that it doesn't need to be
      frequently recomputed.  Initialized by dsbt_relocate_main_executable.  */
-  struct lm_info *main_executable_lm_info;
+  struct lm_info_dsbt *main_executable_lm_info;
 
   /* Load maps for the main executable and the interpreter.  These are obtained
      from ptrace.  They are the starting point for getting into the program,
@@ -711,8 +711,9 @@ dsbt_current_sos (void)
 	    }
 
 	  sop = XCNEW (struct so_list);
-	  sop->lm_info = XCNEW (struct lm_info);
-	  sop->lm_info->map = loadmap;
+	  lm_info_dsbt *li = XCNEW (lm_info_dsbt);
+	  sop->lm_info = li;
+	  li->map = loadmap;
 	  /* Fetch the name.  */
 	  addr = extract_unsigned_integer (lm_buf.l_name,
 					   sizeof (lm_buf.l_name),
@@ -930,7 +931,7 @@ dsbt_relocate_main_executable (void)
   ldm = info->exec_loadmap;
 
   xfree (info->main_executable_lm_info);
-  info->main_executable_lm_info = XCNEW (struct lm_info);
+  info->main_executable_lm_info = XCNEW (lm_info_dsbt);
   info->main_executable_lm_info->map = ldm;
 
   new_offsets = XCNEWVEC (struct section_offsets,
@@ -1016,8 +1017,10 @@ dsbt_clear_solib (void)
 static void
 dsbt_free_so (struct so_list *so)
 {
-  xfree (so->lm_info->map);
-  xfree (so->lm_info);
+  lm_info_dsbt *li = (lm_info_dsbt *) so->lm_info;
+
+  xfree (li->map);
+  xfree (li);
 }
 
 static void
@@ -1025,9 +1028,8 @@ dsbt_relocate_section_addresses (struct so_list *so,
 				 struct target_section *sec)
 {
   int seg;
-  struct int_elf32_dsbt_loadmap *map;
-
-  map = so->lm_info->map;
+  lm_info_dsbt *li = (lm_info_dsbt *) so->lm_info;
+  int_elf32_dsbt_loadmap *map = li->map;
 
   for (seg = 0; seg < map->nsegs; seg++)
     {
-- 
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