section-select: Lazily resolve section matches

and remember the results.  Before this the order of section matching
is basically:

  foreach script-wild-stmt S
    foreach pattern P of S
      foreach inputfile I
        foreach section S of I
	  match S against P
	    if match: do action for S

And this process is done three or four times: for each top-level call to
walk_wild() or wild(), that is: check_input_sections, lang_gc_sections,
lang_find_relro_sections and of course map_input_to_output_sections.

So we iterate over all sections of all files many many times (for each
glob).  Reality is a bit more complicated (some special glob types don't
need the full iteration over all sections, only over all files), but
that's the gist of it.

For future work this shuffles the whole ordering a bit by lazily doing
the matching process and memoizing results, trading a little memory for
a 75% speedup of the overall section selection process.

This lazy resolution introduces a problem with sections added late
that's corrected in the next patch.

1 files changed, 87 insertions, 1 deletions

diff --git a/ld/ldlang.c b/ld/ldlang.c
index 336eea913c7..846dcdf2918 100644
--- a/ld/ldlang.c
+++ b/ld/ldlang.c
@@ -1077,8 +1077,27 @@ walk_wild_file (lang_wild_statement_type *s,
     }
 }
 
+static lang_statement_union_type *
+new_statement (enum statement_enum type,
+	       size_t size,
+	       lang_statement_list_type *list);
 static void
-walk_wild (lang_wild_statement_type *s, callback_t callback, void *data)
+add_matching_callback (lang_wild_statement_type *ptr,
+		       struct wildcard_list *sec,
+		       asection *section,
+		       lang_input_statement_type *file,
+		       void *data ATTRIBUTE_UNUSED)
+{
+  lang_input_matcher_type *new_section;
+  /* Add a section reference to the list.  */
+  new_section = new_stat (lang_input_matcher, &ptr->matching_sections);
+  new_section->section = section;
+  new_section->pattern = sec;
+  new_section->input_stmt = file;
+}
+
+static void
+walk_wild_resolve (lang_wild_statement_type *s)
 {
   const char *file_spec = s->filename;
   char *p;
@@ -1088,6 +1107,66 @@ walk_wild (lang_wild_statement_type *s, callback_t callback, void *data)
       /* Perform the iteration over all files in the list.  */
       LANG_FOR_EACH_INPUT_STATEMENT (f)
 	{
+	  //printf("XXX   %s\n", f->filename);
+	  walk_wild_file (s, f, add_matching_callback, NULL);
+	}
+    }
+  else if ((p = archive_path (file_spec)) != NULL)
+    {
+      LANG_FOR_EACH_INPUT_STATEMENT (f)
+	{
+	  if (input_statement_is_archive_path (file_spec, p, f))
+	    walk_wild_file (s, f, add_matching_callback, NULL);
+	}
+    }
+  else if (wildcardp (file_spec))
+    {
+      LANG_FOR_EACH_INPUT_STATEMENT (f)
+	{
+	  if (fnmatch (file_spec, f->filename, 0) == 0)
+	    walk_wild_file (s, f, add_matching_callback, NULL);
+	}
+    }
+  else
+    {
+      lang_input_statement_type *f;
+
+      /* Perform the iteration over a single file.  */
+      f = lookup_name (file_spec);
+      if (f)
+	walk_wild_file (s, f, add_matching_callback, NULL);
+    }
+}
+
+static void
+walk_wild (lang_wild_statement_type *s, callback_t callback, void *data)
+{
+  const char *file_spec = s->filename;
+  //char *p;
+
+  if (!s->resolved)
+    {
+      //printf("XXX %s\n", file_spec ? file_spec : "<null>");
+      walk_wild_resolve (s);
+      s->resolved = true;
+    }
+
+    {
+      lang_statement_union_type *l;
+      for (l = s->matching_sections.head; l; l = l->header.next)
+	{
+	  (*callback) (s, l->input_matcher.pattern, l->input_matcher.section, l->input_matcher.input_stmt, data);
+	}
+      return;
+    }
+
+#if 0
+  if (file_spec == NULL)
+    {
+      /* Perform the iteration over all files in the list.  */
+      LANG_FOR_EACH_INPUT_STATEMENT (f)
+	{
+	  printf("XXX   %s\n", f->filename);
 	  walk_wild_file (s, f, callback, data);
 	}
     }
@@ -1116,6 +1195,7 @@ walk_wild (lang_wild_statement_type *s, callback_t callback, void *data)
       if (f)
 	walk_wild_file (s, f, callback, data);
     }
+#endif
 }
 
 /* lang_for_each_statement walks the parse tree and calls the provided
@@ -1987,6 +2067,8 @@ insert_os_after (lang_output_section_statement_type *after)
 	case lang_group_statement_enum:
 	case lang_insert_statement_enum:
 	  continue;
+	case lang_input_matcher_enum:
+	  FAIL ();
 	}
       break;
     }
@@ -4352,6 +4434,8 @@ map_input_to_output_sections
 	  break;
 	case lang_insert_statement_enum:
 	  break;
+	case lang_input_matcher_enum:
+	  FAIL ();
 	}
     }
 }
@@ -8348,6 +8432,8 @@ lang_add_wild (struct wildcard_spec *filespec,
   new_stmt->section_list = section_list;
   new_stmt->keep_sections = keep_sections;
   lang_list_init (&new_stmt->children);
+  new_stmt->resolved = false;
+  lang_list_init (&new_stmt->matching_sections);
   analyze_walk_wild_section_handler (new_stmt);
 }