Remove dwarf2_per_bfd::all_type_units

I don't think there is any deep reason to separate CUs and TUs in
dwarf2_per_bfd.  This patch removes all_type_units and unifies these
two containers.  Some minor tweaks are needed to the index writers,
because both forms of index keep CUs and TUs separate;

Regression tested on x86-63 Fedora 32.

gdb/ChangeLog
2021-04-30  Tom Tromey  <tom@tromey.com>

	* dwarf2/read.h (struct tu_stats) <nr_tus>: New member.
	(struct dwarf2_per_bfd) <get_cutu, get_tu>: Remove
	<get_cu>: Now inline.
	<all_type_units>: Remove.
	* dwarf2/read.c (dwarf2_per_bfd::~dwarf2_per_bfd): Update.
	(dwarf2_per_bfd::get_cutu, dwarf2_per_bfd::get_cu)
	(dwarf2_per_bfd::get_tu): Remove.
	(dwarf2_per_bfd::allocate_signatured_type): Update nr_tus.
	(create_signatured_type_table_from_index)
	(create_signatured_type_table_from_debug_names)
	(dw2_symtab_iter_next, dwarf2_base_index_functions::print_stats)
	(dwarf2_base_index_functions::expand_all_symtabs)
	(dw2_expand_marked_cus, dw_expand_symtabs_matching_file_matcher)
	(dwarf2_base_index_functions::map_symbol_filenames)
	(dw2_debug_names_iterator::next, dwarf2_initialize_objfile)
	(add_signatured_type_cu_to_table, create_all_type_units)
	(add_type_unit, build_type_psymtabs_1, print_tu_stats)
	(create_all_comp_units): Update.
	* dwarf2/index-write.c (check_dwarf64_offsets, write_gdbindex)
	(write_debug_names): Update.

1 files changed, 6 insertions, 26 deletions

diff --git a/gdb/dwarf2/read.h b/gdb/dwarf2/read.h
index 98ace89..80f0e3e 100644
--- a/gdb/dwarf2/read.h
+++ b/gdb/dwarf2/read.h
@@ -42,6 +42,7 @@ struct tu_stats
   int nr_symtab_sharers;
   int nr_stmt_less_type_units;
   int nr_all_type_units_reallocs;
+  int nr_tus;
 };
 
 struct dwarf2_cu;
@@ -93,29 +94,11 @@ struct dwarf2_per_bfd
 
   DISABLE_COPY_AND_ASSIGN (dwarf2_per_bfd);
 
-  /* Return the CU/TU given its index.
-
-     This is intended for loops like:
-
-     for (i = 0; i < (dwarf2_per_bfd->n_comp_units
-		      + dwarf2_per_bfd->n_type_units); ++i)
-       {
-	 dwarf2_per_cu_data *per_cu = dwarf2_per_bfd->get_cutu (i);
-
-	 ...;
-       }
-  */
-  dwarf2_per_cu_data *get_cutu (int index);
-
-  /* Return the CU given its index.
-     This differs from get_cutu in that it's for when you know INDEX refers to a
-     CU.  */
-  dwarf2_per_cu_data *get_cu (int index);
-
-  /* Return the TU given its index.
-     This differs from get_cutu in that it's for when you know INDEX refers to a
-     TU.  */
-  signatured_type *get_tu (int index);
+  /* Return the CU given its index.  */
+  dwarf2_per_cu_data *get_cu (int index) const
+  {
+    return this->all_comp_units[index].get ();
+  }
 
   /* A convenience function to allocate a dwarf2_per_cu_data.  The
      returned object has its "index" field set properly.  The object
@@ -173,9 +156,6 @@ public:
      the target compilation unit of a particular reference.  */
   std::vector<std::unique_ptr<dwarf2_per_cu_data>> all_comp_units;
 
-  /* The .debug_types-related CUs (TUs).  */
-  std::vector<std::unique_ptr<signatured_type>> all_type_units;
-
   /* Table of struct type_unit_group objects.
      The hash key is the DW_AT_stmt_list value.  */
   htab_up type_unit_groups;