genksyms: Do not expand internal types

Consider structures, unions and enums defined in the source file as
internal and do not expand them. This way, changes to e.g. struct
serial_private in drivers/tty/serial/8250_pci.c will not affect the
checksum of the pciserial_* exports.

scripts/genksyms/genksyms.c

···
 static FILE *debugfile;
 
 int cur_line = 1;
-char *cur_filename;
+char *cur_filename, *source_file;
+int in_source_file;
 
 static int flag_debug, flag_dump_defs, flag_reference, flag_dump_types,
 	   flag_preserve, flag_warnings;

scripts/genksyms/genksyms.h

···
 struct string_list {
 	struct string_list *next;
 	enum symbol_type tag;
+	int in_source_file;
 	char *string;
 };
 
···
 #define YYSTYPE yystype
 
 extern int cur_line;
-extern char *cur_filename;
+extern char *cur_filename, *source_file;
+extern int in_source_file;
 
 struct symbol *find_symbol(const char *name, enum symbol_type ns, int exact);
 struct symbol *add_symbol(const char *name, enum symbol_type type,

scripts/genksyms/lex.l

···
 			  cur_node->tag =				   \
 			    find_symbol(cur_node->string, SYM_ENUM_CONST, 1)?\
 			    SYM_ENUM_CONST : SYM_NORMAL ;		   \
+			  cur_node->in_source_file = in_source_file;       \
 			} while (0)
 
 #define APP		_APP(yytext, yyleng)
···
       *e = '\0';
       cur_filename = memcpy(xmalloc(e-file+1), file, e-file+1);
       cur_line = atoi(yytext+2);
+
+      if (!source_file) {
+        source_file = xstrdup(cur_filename);
+        in_source_file = 1;
+      } else {
+        in_source_file = (strcmp(cur_filename, source_file) == 0);
+      }
 
       goto repeat;
     }

scripts/genksyms/parse.y

···
 		       enum symbol_type type)
 {
 	struct string_list *b = *body, *i = *ident, *r;
+
+	if (i->in_source_file) {
+		remove_node(keyw);
+		(*ident)->tag = type;
+		remove_list(body, ident);
+		return;
+	}
 	r = copy_node(i); r->tag = type;
 	r->next = (*keyw)->next; *body = r; (*keyw)->next = NULL;
 	add_symbol(i->string, type, b, is_extern);