2004-01-26 Andrew Cagney <cagney@redhat.com>

	* dwarf2loc.c (dwarf_expr_frame_base): Use SYMBOL_OPS instead of
	SYMBOL_LOCATION_FUNCS
	(dwarf2_loclist_funcs, dwarf2_locexpr_funcs): Change type to
	"struct symbol_ops".
	* dwarf2loc.h (dwarf2_locexpr_funcs, dwarf2_loclist_funcs): Change
	type to "struct symbol_ops".
	* symtab.h (struct symbol_ops): Rename "struct location_funcs".
	(struct symbol): Replace ".aux_value.loc.funcs" and
	".aux_value.loc.baton" with ".ops" and ".aux_value.ptr".
	(SYMBOL_OBJFILE): Delete macro.
	(SYMBOL_LOCATION_FUNCS): Delete macro.
	(SYMBOL_LOCATION_BATON): Update.
	* dwarf2read.c (dwarf2_symbol_mark_computed): Set SYMBOL_OPS
	intead of SYMBOL_LOCATION_FUNCS.
	* ax-gdb.c (gen_var_ref): Ditto.
	* printcmd.c (address_info): Ditto.
	* findvar.c (read_var_value): Ditto.
	(symbol_read_needs_frame): Ditto.

1 files changed, 30 insertions, 31 deletions

diff --git a/gdb/symtab.h b/gdb/symtab.h
index 95813bd..c56c053 100644
--- a/gdb/symtab.h
+++ b/gdb/symtab.h
@@ -546,21 +546,12 @@ enum address_class
   LOC_COMPUTED_ARG
 };
 
-/* A structure of function pointers describing the location of a
-   variable, structure member, or structure base class.
-
-   These functions' BATON arguments are generic data pointers, holding
-   whatever data the functions need --- the code which provides this
-   structure also provides the actual contents of the baton, and
-   decides its form.  However, there may be other rules about where
-   the baton data must be allocated; whoever is pointing to this
-   `struct location_funcs' object will know the rules.  For example,
-   when a symbol S's location is LOC_COMPUTED, then
-   SYMBOL_LOCATION_FUNCS(S) is pointing to a location_funcs structure,
-   and SYMBOL_LOCATION_BATON(S) is the baton, which must be allocated
-   on the same obstack as the symbol itself.  */
-
-struct location_funcs
+/* The methods needed to implement a symbol class.  These methods can
+   use the symbol's .aux_value for additional per-symbol information.
+
+   At present this is only used to implement location expressions.  */
+
+struct symbol_ops
 {
 
   /* Return the value of the variable SYMBOL, relative to the stack
@@ -608,6 +599,12 @@ struct symbol
   ENUM_BITFIELD(domain_enum_tag) domain : 6;
 
   /* Address class */
+  /* NOTE: cagney/2003-11-02: The fields "aclass" and "ops" contain
+     overlapping information.  By creating a per-aclass ops vector, or
+     using the aclass as an index into an ops table, the aclass and
+     ops fields can be merged.  The latter, for instance, would shave
+     32-bits from each symbol (relative to a symbol lookup, any table
+     index overhead would be in the noise).  */
 
   ENUM_BITFIELD(address_class) aclass : 6;
 
@@ -617,28 +614,30 @@ struct symbol
 
   unsigned short line;
 
-  /* Some symbols require an additional value to be recorded on a per-
-     symbol basis.  Stash those values here. */
+  /* Method's for symbol's of this class.  */
+  /* NOTE: cagney/2003-11-02: See comment above attached to "aclass".  */
+
+  const struct symbol_ops *ops;
+
+  /* Some symbols require additional information to be recorded on a
+     per- symbol basis.  Stash those values here. */
 
   union
   {
     /* Used by LOC_BASEREG and LOC_BASEREG_ARG.  */
     short basereg;
-
-    /* For a LOC_COMPUTED or LOC_COMPUTED_ARG symbol, this is the
-       baton and location_funcs structure to find its location.  For a
-       LOC_BLOCK symbol for a function in a compilation unit compiled
-       with DWARF 2 information, this is information used internally
-       by the DWARF 2 code --- specifically, the location expression
-       for the frame base for this function.  */
+    /* An arbitrary data pointer.  Note that this data must be
+       allocated using the same obstack as the symbol itself.  */
+    /* So far it is only used by LOC_COMPUTED and LOC_COMPUTED_ARG to
+       find the location location information.  For a LOC_BLOCK symbol
+       for a function in a compilation unit compiled with DWARF 2
+       information, this is information used internally by the DWARF 2
+       code --- specifically, the location expression for the frame
+       base for this function.  */
     /* FIXME drow/2003-02-21: For the LOC_BLOCK case, it might be better
        to add a magic symbol to the block containing this information,
        or to have a generic debug info annotation slot for symbols.  */
-    struct
-    {
-      void *baton;
-      struct location_funcs *funcs;
-    } loc;
+    void *ptr;
   }
   aux_value;
 
@@ -652,8 +651,8 @@ struct symbol
 #define SYMBOL_LINE(symbol)		(symbol)->line
 #define SYMBOL_BASEREG(symbol)		(symbol)->aux_value.basereg
 #define SYMBOL_OBJFILE(symbol)          (symbol)->aux_value.objfile
-#define SYMBOL_LOCATION_BATON(symbol)   (symbol)->aux_value.loc.baton
-#define SYMBOL_LOCATION_FUNCS(symbol)   (symbol)->aux_value.loc.funcs
+#define SYMBOL_OPS(symbol)              (symbol)->ops
+#define SYMBOL_LOCATION_BATON(symbol)   (symbol)->aux_value.ptr
 
 /* A partial_symbol records the name, domain, and address class of
    symbols whose types we have not parsed yet.  For functions, it also