gendwarfksyms: Expand array_type

Add support for expanding DW_TAG_array_type, and the subrange type
indicating array size.

Example source code:

  const char *s[34];

Output with --debug:

  variable array_type [34] {
    pointer_type <unnamed> {
      const_type <unnamed> {
        base_type char byte_size(1) encoding(6)
      }
    } byte_size(8)
  };

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

Author: samitolvanen

scripts/gendwarfksyms/dwarf.c

@@ -218,6 +218,7 @@ DEFINE_PROCESS_UDATA_ATTRIBUTE(encoding)
 	}
 
 DEFINE_MATCH(formal_parameter)
+DEFINE_MATCH(subrange)
 
 bool match_all(Dwarf_Die *die)
 {
@@ -309,6 +310,34 @@ DEFINE_PROCESS_TYPE(shared)
 DEFINE_PROCESS_TYPE(volatile)
 DEFINE_PROCESS_TYPE(typedef)
 
+static int process_subrange_type(struct state *state, struct die *cache,
+				 Dwarf_Die *die)
+{
+	Dwarf_Word count = 0;
+
+	if (get_udata_attr(die, DW_AT_count, &count))
+		return check(process_fmt(state, cache, "[%" PRIu64 "]", count));
+	if (get_udata_attr(die, DW_AT_upper_bound, &count))
+		return check(
+			process_fmt(state, cache, "[%" PRIu64 "]", count + 1));
+
+	return check(process(state, cache, "[]"));
+}
+
+static int process_array_type(struct state *state, struct die *cache,
+			      Dwarf_Die *die)
+{
+	check(process(state, cache, "array_type "));
+	/* Array size */
+	check(process_die_container(state, cache, die, process_type,
+				    match_subrange_type));
+	check(process(state, cache, " {"));
+	check(process_linebreak(cache, 1));
+	check(process_type_attr(state, cache, die));
+	check(process_linebreak(cache, -1));
+	return check(process(state, cache, "}"));
+}
+
 static int __process_subroutine_type(struct state *state, struct die *cache,
 				     Dwarf_Die *die, const char *type)
 {
@@ -411,7 +440,9 @@ static int process_type(struct state *state, struct die *parent, Dwarf_Die *die)
 	PROCESS_TYPE(volatile)
 	/* Subtypes */
 	PROCESS_TYPE(formal_parameter)
+	PROCESS_TYPE(subrange)
 	/* Other types */
+	PROCESS_TYPE(array)
 	PROCESS_TYPE(base)
 	PROCESS_TYPE(subroutine)
 	PROCESS_TYPE(typedef)