[PATCH] eliminate elif_ignore, fix handling of unterminated #if

No need to bother with stack; we can just keep # tokens from #if...  and
use _those_ as a stack instead.  struct stream gets a pointer to the
current #if..., checks for #elif/#else/#endif out of place become simple
if (!stream->top_if) and stream->ifndef becomes a pointer to token
instead of an integer (pointer to token in that stack instead of nesting
depth).

We lose elif_ignore[] array, if_nesting and stream->nesting (nothing
cares of those anymore) and get sane handling of unterminated #if for
free - instead of reporting the location of the last #if on depth 0
(very likely - in another file and having an #endif) we can give
location of the #if that really lacks #endif.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/token.h b/token.h
index aff5bbc..96b0c41 100644
--- a/token.h
+++ b/token.h
@@ -40,10 +40,10 @@ struct stream {
 
 	/* Use these to check for "already parsed" */
 	enum constantfile constant;
-	int nesting;
-	int ifndef;
 	int dirty;
 	struct ident *protect;
+	struct token *ifndef;
+	struct token *top_if;
 };
 
 extern int input_stream_nr;
@@ -76,6 +76,9 @@ enum token_type {
 	TOKEN_GNU_KLUDGE,
 	TOKEN_UNTAINT,
 	TOKEN_ARG_COUNT,
+	TOKEN_IF,
+	TOKEN_SKIP_GROUPS,
+	TOKEN_ELSE,
 };
 
 /* Combination tokens */