[PATCH] Remove unused decl_scope_table

[Richard Biener <rguenther at suse dot de>]

Formerly used by scope_die_for this stack is now unused and just
pushed/popped to/from.

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.

Richard.

2018-06-28  Richard Biener  <rguenther@suse.de>

	* dwarf2out.c (decl_scope_table): Remove.
	(push_decl_scope): Likewise.
	(pop_decl_scope): Likewise.
	(gen_type_die_for_member): Do not call push/pop_decl_scope.
	(gen_struct_or_union_type_die): Likewise.
	(gen_tagged_type_die): Likewise.
	(dwarf2out_init): Do not initialize decl_scope_table.
	(dwarf2out_c_finalize): Do not free it.

Index: gcc/dwarf2out.c
===================================================================
--- gcc/dwarf2out.c	(revision 262217)
+++ gcc/dwarf2out.c	(working copy)
@@ -150,13 +150,6 @@ static GTY(()) vec<rtx, va_gc> *used_rtx
    it.  */
 static GTY(()) vec<tree, va_gc> *incomplete_types;
 
-/* A pointer to the base of a table of references to declaration
-   scopes.  This table is a display which tracks the nesting
-   of declaration scopes at the current scope and containing
-   scopes.  This table is used to find the proper place to
-   define type declaration DIE's.  */
-static GTY(()) vec<tree, va_gc> *decl_scope_table;
-
 /* Pointers to various DWARF2 sections.  */
 static GTY(()) section *debug_info_section;
 static GTY(()) section *debug_skeleton_info_section;
@@ -3835,8 +3828,6 @@ static void add_name_and_src_coords_attr
 static void add_discr_value (dw_die_ref, dw_discr_value *);
 static void add_discr_list (dw_die_ref, dw_discr_list_ref);
 static inline dw_discr_list_ref AT_discr_list (dw_attr_node *);
-static void push_decl_scope (tree);
-static void pop_decl_scope (void);
 static dw_die_ref scope_die_for (tree, dw_die_ref);
 static inline int local_scope_p (dw_die_ref);
 static inline int class_scope_p (dw_die_ref);
@@ -21361,22 +21352,6 @@ dwarf2out_vms_debug_main_pointer (void)
 }
 #endif /* VMS_DEBUGGING_INFO */
 
-/* Push a new declaration scope.  */
-
-static void
-push_decl_scope (tree scope)
-{
-  vec_safe_push (decl_scope_table, scope);
-}
-
-/* Pop a declaration scope.  */
-
-static inline void
-pop_decl_scope (void)
-{
-  decl_scope_table->pop ();
-}
-
 /* walk_tree helper function for uses_local_type, below.  */
 
 static tree
@@ -22359,7 +22334,6 @@ gen_type_die_for_member (tree type, tree
       dw_die_ref type_die;
       gcc_assert (!decl_ultimate_origin (member));
 
-      push_decl_scope (type);
       type_die = lookup_type_die_strip_naming_typedef (type);
       if (TREE_CODE (member) == FUNCTION_DECL)
 	gen_subprogram_die (member, type_die);
@@ -22381,8 +22355,6 @@ gen_type_die_for_member (tree type, tree
 	}
       else
 	gen_variable_die (member, NULL_TREE, type_die);
-
-      pop_decl_scope ();
     }
 }
 
@@ -25153,9 +25125,7 @@ gen_struct_or_union_type_die (tree type,
       if (type_die->die_parent == NULL)
 	add_child_die (scope_die, type_die);
 
-      push_decl_scope (type);
       gen_member_die (type, type_die);
-      pop_decl_scope ();
 
       add_gnat_descriptive_type_attribute (type_die, type, context_die);
       if (TYPE_ARTIFICIAL (type))
@@ -25309,14 +25279,12 @@ gen_tagged_type_die (tree type,
 		     dw_die_ref context_die,
 		     enum debug_info_usage usage)
 {
-  int need_pop;
-
   if (type == NULL_TREE
       || !is_tagged_type (type))
     return;
 
   if (TREE_ASM_WRITTEN (type))
-    need_pop = 0;
+    ;
   /* If this is a nested type whose containing class hasn't been written
      out yet, writing it out will cover this one, too.  This does not apply
      to instantiations of member class templates; they need to be added to
@@ -25333,9 +25301,7 @@ gen_tagged_type_die (tree type,
 	return;
 
       /* If that failed, attach ourselves to the stub.  */
-      push_decl_scope (TYPE_CONTEXT (type));
       context_die = lookup_type_die (TYPE_CONTEXT (type));
-      need_pop = 1;
     }
   else if (TYPE_CONTEXT (type) != NULL_TREE
 	   && (TREE_CODE (TYPE_CONTEXT (type)) == FUNCTION_DECL))
@@ -25348,13 +25314,9 @@ gen_tagged_type_die (tree type,
 	 specification.  */
       if (context_die && is_declaration_die (context_die))
 	context_die = NULL;
-      need_pop = 0;
     }
   else
-    {
-      context_die = declare_in_namespace (type, context_die);
-      need_pop = 0;
-    }
+    context_die = declare_in_namespace (type, context_die);
 
   if (TREE_CODE (type) == ENUMERAL_TYPE)
     {
@@ -25366,9 +25328,6 @@ gen_tagged_type_die (tree type,
   else
     gen_struct_or_union_type_die (type, context_die, usage);
 
-  if (need_pop)
-    pop_decl_scope ();
-
   /* Don't set TREE_ASM_WRITTEN on an incomplete struct; we want to fix
      it up if it is ever completed.  gen_*_type_die will set it for us
      when appropriate.  */
@@ -28658,9 +28617,6 @@ dwarf2out_init (const char *filename ATT
   /* Allocate the cached_dw_loc_list_table.  */
   cached_dw_loc_list_table = hash_table<dw_loc_list_hasher>::create_ggc (10);
 
-  /* Allocate the initial hunk of the decl_scope_table.  */
-  vec_alloc (decl_scope_table, 256);
-
   /* Allocate the initial hunk of the abbrev_die_table.  */
   vec_alloc (abbrev_die_table, 256);
   /* Zero-th entry is allocated, but unused.  */
@@ -32102,7 +32058,6 @@ dwarf2out_c_finalize (void)
   cached_next_real_insn = NULL;
   used_rtx_array = NULL;
   incomplete_types = NULL;
-  decl_scope_table = NULL;
   debug_info_section = NULL;
   debug_skeleton_info_section = NULL;
   debug_abbrev_section = NULL;