From 7207be8d9e4de12b91e8b7f4a5a82019a5c48744 Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@tv-sign.ru>
Date: Mon, 2 Jan 2006 22:20:12 +0300
Subject: [PATCH] fix 'weak' attribute loss

When NS_MACRO symbol is used, sparse clears it's 'weak' flag.
This is bad for multifile parsing, and wrong:

	#weak_define FOO 1
	FOO
	#weak_define FOO 2	// silently ignored

After this patch sparse never writes to NS_MACRO symbols from
another scope (except ->used_in).

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
---
 pre-process.c | 8 +++++---
 symbol.h      | 1 +
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/pre-process.c b/pre-process.c
index 6f3145f8..63f83dbb 100644
--- a/pre-process.c
+++ b/pre-process.c
@@ -118,7 +118,7 @@ static int token_defined(struct token *token)
 	if (token_type(token) == TOKEN_IDENT) {
 		struct symbol *sym = lookup_macro(token->ident);
 		if (sym) {
-			sym->weak = 0;
+			sym->used_in = file_scope;
 			return 1;
 		}
 		return 0;
@@ -147,7 +147,7 @@ static int expand_one_symbol(struct token **list)
 
 	sym = lookup_macro(token->ident);
 	if (sym) {
-		sym->weak = 0;
+		sym->used_in = file_scope;
 		return expand(list, sym);
 	}
 	if (token->ident == &__LINE___ident) {
@@ -1100,7 +1100,7 @@ static int do_handle_define(struct stream *stream, struct token **line, struct t
 		if (token_list_different(sym->expansion, expansion) ||
 		    token_list_different(sym->arglist, arglist)) {
 			ret = 0;
-			if (clean && !weak) {
+			if ((clean && !weak) || sym->used_in == file_scope) {
 				warning(left->pos, "preprocessor token %.*s redefined",
 						name->len, name->name);
 				info(sym->pos, "this was the original definition");
@@ -1121,6 +1121,7 @@ static int do_handle_define(struct stream *stream, struct token **line, struct t
 		__free_token(token);	/* Free the "define" token, but not the rest of the line */
 	}
 
+	sym->used_in = NULL;
 	sym->weak = weak;
 out:
 	return ret;
@@ -1156,6 +1157,7 @@ static int handle_undef(struct stream *stream, struct token **line, struct token
 	}
 
 	sym->namespace = NS_UNDEF;
+	sym->used_in = NULL;
 
 	return 1;
 }
diff --git a/symbol.h b/symbol.h
index e3b6b450..498e6e35 100644
--- a/symbol.h
+++ b/symbol.h
@@ -99,6 +99,7 @@ struct symbol {
 		struct /* NS_MACRO */ {
 			struct token *expansion;
 			struct token *arglist;
+			struct scope *used_in;
 		};
 		struct /* NS_PREPROCESSOR */ {
 			int (*handler)(struct stream *, struct token **, struct token *);
-- 
2.11.4.GIT