Introduce class psymtab_storage

This introduces a new psymtab_storage class, which holds all
psymbol-related objects that are independent of the objfile.  (This
latter contraint explains why psymbol_map was not moved; though this
could still be done with some work.)

This patch does not yet change where psymtab allocation is done --
that comes later.  This just wraps everything in a single object to
make further transformations simpler.

Note that a shared_ptr is used to link from the objfile to the
psymtab_storage object.  The end goal here is to allow a given symbol
reader to simply attach to the psymtab_storage object to the BFD, then
reuse it in later invocations; shared_ptr makes this simple to reason
about.

gdb/ChangeLog
2019-01-10  Tom Tromey  <tom@tromey.com>

	* symmisc.c (print_symbol_bcache_statistics): Update.
	(print_objfile_statistics): Update.
	* symfile.c (reread_symbols): Update.
	* psymtab.h (class psymtab_storage): New.
	* psymtab.c (psymtab_storage): New constructor.
	(~psymtab_storage): New destructor.
	(require_partial_symbols): Update.
	(ALL_OBJFILE_PSYMTABS_REQUIRED): Rewrite.
	(find_pc_sect_psymtab, find_pc_sect_psymbol)
	(match_partial_symbol, lookup_partial_symbol, dump_psymtab)
	(psym_dump, recursively_search_psymtabs, psym_has_symbols)
	(psym_find_compunit_symtab_by_address, sort_pst_symbols)
	(start_psymtab_common, end_psymtab_common)
	(add_psymbol_to_bcache, add_psymbol_to_list, init_psymbol_list)
	(allocate_psymtab): Update.
	(psymtab_storage::discard_psymtab): Rename from discard_psymtab.
	Update.
	(dump_psymtab_addrmap, maintenance_print_psymbols)
	(maintenance_check_psymtabs): Update.
	(class objfile_psymtabs): Move to objfiles.h.
	* psympriv.h (discard_psymtab): Now inline.
	(psymtab_discarder::psymtab_discarder): Update.
	(psymtab_discarder::~psymtab_discarder): Update.
	(ALL_OBJFILE_PSYMTABS): Rewrite.
	* objfiles.h (struct objfile) <psymtabs, psymtabs_addrmap,
	free_psymtabs, psymbol_cache, global_psymbols, static_psymbols>:
	Remove fields.
	<partial_symtabs>: New field.
	(class objfile_psymtabs): Move from psymtab.h.  Update.
	* objfiles.c (objfile::objfile): Initialize partial_symtabs, not
	psymbol_cache.
	(objfile::~objfile): Don't destroy psymbol_cache.
	* mdebugread.c (parse_partial_symbols): Update.
	* dwarf2read.c (create_addrmap_from_index)
	(create_addrmap_from_aranges, dw2_find_pc_sect_compunit_symtab)
	(process_psymtab_comp_unit_reader, dwarf2_build_psymtabs_hard)
	(add_partial_subprogram, dwarf2_ranges_read): Update.
	* dwarf-index-write.c (write_address_map)
	(write_one_signatured_type, recursively_write_psymbols)
	(class debug_names, class debug_names, write_psymtabs_to_index):
	Update.

1 files changed, 64 insertions, 13 deletions

diff --git a/gdb/psymtab.h b/gdb/psymtab.h
index a1cab96..895f950 100644
--- a/gdb/psymtab.h
+++ b/gdb/psymtab.h
@@ -23,37 +23,88 @@
 #include "symfile.h"
 #include "common/next-iterator.h"
 
+struct partial_symbol;
+
 /* A bcache for partial symbols.  */
 
 struct psymbol_bcache;
 
-extern struct psymbol_bcache *psymbol_bcache_init (void);
-extern void psymbol_bcache_free (struct psymbol_bcache *);
-extern struct bcache *psymbol_bcache_get_bcache (struct psymbol_bcache *);
+/* An instance of this class manages the partial symbol tables and
+   partial symbols for a given objfile.  */
 
-extern const struct quick_symbol_functions psym_functions;
+class psymtab_storage
+{
+public:
 
-extern const struct quick_symbol_functions dwarf2_gdb_index_functions;
-extern const struct quick_symbol_functions dwarf2_debug_names_functions;
+  explicit psymtab_storage (struct objfile *objfile);
 
-/* A range adapter that makes it possible to iterate over all
-   psymtabs in one objfile.  */
+  ~psymtab_storage ();
 
-class objfile_psymtabs : public next_adapter<struct partial_symtab>
-{
-public:
+  DISABLE_COPY_AND_ASSIGN (psymtab_storage);
+
+  /* Discard all partial symbol tables starting with "psymtabs" and
+     proceeding until "to" has been discarded.  */
 
-  explicit objfile_psymtabs (struct objfile *objfile)
-    : next_adapter<struct partial_symtab> (objfile->psymtabs)
+  void discard_psymtabs_to (struct partial_symtab *to)
   {
+    while (psymtabs != to)
+      discard_psymtab (psymtabs);
   }
+
+  /* Discard the partial symbol table.  */
+
+  void discard_psymtab (struct partial_symtab *pst);
+
+
+  /* Each objfile points to a linked list of partial symtabs derived from
+     this file, one partial symtab structure for each compilation unit
+     (source file).  */
+
+  struct partial_symtab *psymtabs = nullptr;
+
+  /* Map addresses to the entries of PSYMTABS.  It would be more efficient to
+     have a map per the whole process but ADDRMAP cannot selectively remove
+     its items during FREE_OBJFILE.  This mapping is already present even for
+     PARTIAL_SYMTABs which still have no corresponding full SYMTABs read.  */
+
+  struct addrmap *psymtabs_addrmap = nullptr;
+
+  /* List of freed partial symtabs, available for re-use.  */
+
+  struct partial_symtab *free_psymtabs = nullptr;
+
+  /* The obstack where allocations are made.  */
+
+  struct obstack *obstack;
+
+  /* A byte cache where we can stash arbitrary "chunks" of bytes that
+     will not change.  */
+
+  struct psymbol_bcache *psymbol_cache;
+
+  /* Vectors of all partial symbols read in from file.  The actual data
+     is stored in the objfile_obstack.  */
+
+  std::vector<partial_symbol *> global_psymbols;
+  std::vector<partial_symbol *> static_psymbols;
 };
 
+
+extern struct psymbol_bcache *psymbol_bcache_init (void);
+extern void psymbol_bcache_free (struct psymbol_bcache *);
+extern struct bcache *psymbol_bcache_get_bcache (struct psymbol_bcache *);
+
+extern const struct quick_symbol_functions psym_functions;
+
+extern const struct quick_symbol_functions dwarf2_gdb_index_functions;
+extern const struct quick_symbol_functions dwarf2_debug_names_functions;
+
 /* Ensure that the partial symbols for OBJFILE have been loaded.  If
    VERBOSE is non-zero, then this will print a message when symbols
    are loaded.  This function returns a range adapter suitable for
    iterating over the psymtabs of OBJFILE.  */
 
+class objfile_psymtabs;
 extern objfile_psymtabs require_partial_symbols (struct objfile *objfile,
 						 int verbose);