Change representation of psymbol to flush out accessors

This is the psymbol analog to the patch to change the representation
of minimal symbols:

    https://sourceware.org/ml/gdb-patches/2013-10/msg00524.html

It has the same rationale: namely, that we're going to change the code
to apply psymbol offsets at runtime.  This will be done by adding an
argument to the SYMBOL_VALUE_ADDRESS macro -- but since we can't
convert all the symbol types at once, we need a new approach.

Because gdb now is in C++, this patch changes partial_symbol to
inherit from general_symbol_info, rather than renaming the field.
This simplifies code in some places.

Also, as noted before, these macros implement a kind of "phony
polymorphism" that is not actually useful in practice; so this patch
removes the macros in favor of simply referring directly to members.
In a few cases -- obj_section in this patch and the symbol address in
the future -- methods will be used instead.

Note that this removes the blanket memset from add_psymbol_to_bcache.
This hasn't really been needed since bcache was modified to allow
holes in objects and since psymtab took advantage of that.  This
deletion was required due to changing partial_symbol to derive from
general_symbol_info.

gdb/ChangeLog
2018-07-26  Tom Tromey  <tom@tromey.com>

	* dwarf-index-write.c (write_psymbols, debug_names::insert)
	(debug_names::write_psymbols): Update.
	* psympriv.h (struct partial_symbol): Derive from
	general_symbol_info.
	<obj_section>: New method.
	(PSYMBOL_DOMAIN, PSYMBOL_CLASS): Remove.n
	* psymtab.c (find_pc_sect_psymtab_closer, find_pc_sect_psymtab)
	(find_pc_sect_psymbol, fixup_psymbol_section)
	(match_partial_symbol, lookup_partial_symbol, relocate_psymtabs)
	(print_partial_symbols, recursively_search_psymtabs)
	(compare_psymbols, psymbol_hash, psymbol_compare)
	(add_psymbol_to_bcache, maintenance_check_psymtabs)
	(psymbol_name_matches, psym_fill_psymbol_map): Update.

1 files changed, 9 insertions, 7 deletions

diff --git a/gdb/psympriv.h b/gdb/psympriv.h
index 45746a2..f3cb0a6 100644
--- a/gdb/psympriv.h
+++ b/gdb/psympriv.h
@@ -33,11 +33,16 @@
 /* This structure is space critical.  See space comments at the top of
    symtab.h.  */
 
-struct partial_symbol
+struct partial_symbol : public general_symbol_info
 {
-  /* The general symbol info required for all types of symbols.  */
-
-  struct general_symbol_info ginfo;
+  /* Return the section for this partial symbol, or nullptr if no
+     section has been set.  */
+  struct obj_section *obj_section (struct objfile *objfile) const
+  {
+    if (section >= 0)
+      return &objfile->sections[section];
+    return nullptr;
+  }
 
   /* Name space code.  */
 
@@ -50,9 +55,6 @@ struct partial_symbol
   ENUM_BITFIELD(address_class) aclass : SYMBOL_ACLASS_BITS;
 };
 
-#define PSYMBOL_DOMAIN(psymbol)	(psymbol)->domain
-#define PSYMBOL_CLASS(psymbol)		(psymbol)->aclass
-
 /* A convenience enum to give names to some constants used when
    searching psymtabs.  This is internal to psymtab and should not be
    used elsewhere.  */