remove msymbol_objfile

This is another patch in my ongoing series to "split" objfile to share
more read-only data across inferiors.  See

    http://sourceware.org/gdb/wiki/ObjfileSplitting

When symbols are finally shared, there will be no back-link from the
symbol to its containing objfile, because there may be more than one
such objfile.  So, all such back-links must be removed.

One hidden back-link is the msymbol_objfile function.  Since
(eventually) a symbol may appear in more than one objfile, trying to
look up the objfile given just a symbol cannot work.

This patch removes msymbol_objfile in favor of using a bound minimal
symbol.  It introduces a new function to make this conversion simpler
in some spots.

The bonus of this patch is that using msymbol_objfile is slower than
simply looking up the owning objfile in the first place.

Built and regtested on x86-64 Fedora 18.

	* ada-exp.y (write_var_or_type): Use bound_minimal_symbol.
	* ada-lang.c (ada_lookup_simple_minsym): Return
	bound_minimal_symbol.
	* ada-lang.h (ada_lookup_simple_minsym): Update.
	* c-exp.y (variable): Use lookup_bound_minimal_symbol.
	* f-exp.y (variable): Use lookup_bound_minimal_symbol.
	* go-exp.y (variable): Use lookup_bound_minimal_symbol.
	* jv-exp.y (push_expression_name): Use lookup_bound_minimal_symbol.
	* m2-exp.y (variable): Use lookup_bound_minimal_symbol.
	* minsyms.c (msymbol_objfile): Remove.
	(lookup_minimal_symbol_internal): New function, from
	lookup_minimal_symbol.
	(lookup_minimal_symbol): Rewrite using
	lookup_minimal_symbol_internal.
	(lookup_bound_minimal_symbol): New function.
	* minsyms.h (msymbol_objfile): Remove.
	(lookup_bound_minimal_symbol): Declare.
	* p-exp.y (variable): Use lookup_bound_minimal_symbol.
	* parse.c (write_exp_msymbol): Change parameter to a
	bound_minimal_symbol.
	(write_dollar_variable): Use lookup_bound_minimal_symbol.
	* parser-defs.h (write_exp_msymbol): Update.
	* printcmd.c (address_info): Use lookup_bound_minimal_symbol.
	* symfile.c (simple_read_overlay_table): Use
	lookup_bound_minimal_symbol.
	* symtab.c (skip_prologue_sal): Don't use msymbol_objfile.
	(search_symbols): Likewise.
	(print_msymbol_info): Take a bound_minimal_symbol argument.
	(symtab_symbol_info, rbreak_command): Update.
	* symtab.h (struct symbol_search) <msymbol>: Change type
	to bound_minimal_symbol.
	* valops.c (find_function_in_inferior): Use
	lookup_bound_minimal_symbol.
	* value.c (value_fn_field): Use lookup_bound_minimal_symbol.

1 files changed, 6 insertions, 6 deletions

diff --git a/gdb/value.c b/gdb/value.c
index 8d635c7..09ab1bb 100644
--- a/gdb/value.c
+++ b/gdb/value.c
@@ -2773,18 +2773,18 @@ value_fn_field (struct value **arg1p, struct fn_field *f,
   struct type *ftype = TYPE_FN_FIELD_TYPE (f, j);
   const char *physname = TYPE_FN_FIELD_PHYSNAME (f, j);
   struct symbol *sym;
-  struct minimal_symbol *msym;
+  struct bound_minimal_symbol msym;
 
   sym = lookup_symbol (physname, 0, VAR_DOMAIN, 0);
   if (sym != NULL)
     {
-      msym = NULL;
+      memset (&msym, 0, sizeof (msym));
     }
   else
     {
       gdb_assert (sym == NULL);
-      msym = lookup_minimal_symbol (physname, NULL, NULL);
-      if (msym == NULL)
+      msym = lookup_bound_minimal_symbol (physname);
+      if (msym.minsym == NULL)
 	return NULL;
     }
 
@@ -2797,12 +2797,12 @@ value_fn_field (struct value **arg1p, struct fn_field *f,
     {
       /* The minimal symbol might point to a function descriptor;
 	 resolve it to the actual code address instead.  */
-      struct objfile *objfile = msymbol_objfile (msym);
+      struct objfile *objfile = msym.objfile;
       struct gdbarch *gdbarch = get_objfile_arch (objfile);
 
       set_value_address (v,
 	gdbarch_convert_from_func_ptr_addr
-	   (gdbarch, SYMBOL_VALUE_ADDRESS (msym), &current_target));
+	   (gdbarch, SYMBOL_VALUE_ADDRESS (msym.minsym), &current_target));
     }
 
   if (arg1p)