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/parse.c b/gdb/parse.c
index 13699a8..674342b 100644
--- a/gdb/parse.c
+++ b/gdb/parse.c
@@ -496,9 +496,10 @@ write_exp_bitstring (struct stoken str)
    the expression.  */
 
 void
-write_exp_msymbol (struct minimal_symbol *msymbol)
+write_exp_msymbol (struct bound_minimal_symbol bound_msym)
 {
-  struct objfile *objfile = msymbol_objfile (msymbol);
+  struct minimal_symbol *msymbol = bound_msym.minsym;
+  struct objfile *objfile = bound_msym.objfile;
   struct gdbarch *gdbarch = get_objfile_arch (objfile);
 
   CORE_ADDR addr = SYMBOL_VALUE_ADDRESS (msymbol);
@@ -640,7 +641,7 @@ void
 write_dollar_variable (struct stoken str)
 {
   struct symbol *sym = NULL;
-  struct minimal_symbol *msym = NULL;
+  struct bound_minimal_symbol msym;
   struct internalvar *isym = NULL;
 
   /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)
@@ -704,8 +705,8 @@ write_dollar_variable (struct stoken str)
       write_exp_elt_opcode (OP_VAR_VALUE);
       return;
     }
-  msym = lookup_minimal_symbol (copy_name (str), NULL, NULL);
-  if (msym)
+  msym = lookup_bound_minimal_symbol (copy_name (str));
+  if (msym.minsym)
     {
       write_exp_msymbol (msym);
       return;