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, 5 deletions

diff --git a/gdb/symfile.c b/gdb/symfile.c
index 51291054a7c..33286487555 100644
--- a/gdb/symfile.c
+++ b/gdb/symfile.c
@@ -3399,7 +3399,8 @@ read_target_long_array (CORE_ADDR memaddr, unsigned int *myaddr,
 static int
 simple_read_overlay_table (void)
 {
-  struct minimal_symbol *novlys_msym, *ovly_table_msym;
+  struct minimal_symbol *novlys_msym;
+  struct bound_minimal_symbol ovly_table_msym;
   struct gdbarch *gdbarch;
   int word_size;
   enum bfd_endian byte_order;
@@ -3414,8 +3415,8 @@ simple_read_overlay_table (void)
       return 0;
     }
 
-  ovly_table_msym = lookup_minimal_symbol ("_ovly_table", NULL, NULL);
-  if (! ovly_table_msym)
+  ovly_table_msym = lookup_bound_minimal_symbol ("_ovly_table");
+  if (! ovly_table_msym.minsym)
     {
       error (_("Error reading inferior's overlay table: couldn't find "
              "`_ovly_table' array\n"
@@ -3423,7 +3424,7 @@ simple_read_overlay_table (void)
       return 0;
     }
 
-  gdbarch = get_objfile_arch (msymbol_objfile (ovly_table_msym));
+  gdbarch = get_objfile_arch (ovly_table_msym.objfile);
   word_size = gdbarch_long_bit (gdbarch) / TARGET_CHAR_BIT;
   byte_order = gdbarch_byte_order (gdbarch);
 
@@ -3431,7 +3432,7 @@ simple_read_overlay_table (void)
 				      4, byte_order);
   cache_ovly_table
     = (void *) xmalloc (cache_novlys * sizeof (*cache_ovly_table));
-  cache_ovly_table_base = SYMBOL_VALUE_ADDRESS (ovly_table_msym);
+  cache_ovly_table_base = SYMBOL_VALUE_ADDRESS (ovly_table_msym.minsym);
   read_target_long_array (cache_ovly_table_base,
                           (unsigned int *) cache_ovly_table,
                           cache_novlys * 4, word_size, byte_order);