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Date: Thu, 15 Aug 2019 12:12:37 +0100
From: John Levon <levon@movementarian.org>
Subject: Re: noreturn attribute doesn't work in smatch
Message-ID: <20190815111237.GA20100@movementarian.org>
References: <20190815005328.GA8004@movementarian.org>
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Cc: yuri.pankov@nexenta.com


I took another pass, and this works for me:

diff --git a/parse.c b/parse.c
index ca4726b8..44c59707 100644
--- a/parse.c
+++ b/parse.c
@@ -2859,6 +2859,7 @@ struct token *external_declaration(struct token
*token, struct symbol_list **lis
        /* Parse declaration-specifiers, if any */
        token = declaration_specifiers(token, &ctx);
        mod = storage_modifiers(&ctx);
+       mod |= ctx.ctype.modifiers & MOD_NORETURN;
        decl = alloc_symbol(token->pos, SYM_NODE);
        /* Just a type declaration? */
        if (match_op(token, ';')) {

(I suppose a proper fix would collate all function-level attributes
but...)


However, it seems like smatch is still not quite passing its knowledge
along: if I have:

extern void die() __attribute((__noreturn__));

void mydie()
{
	die();
}

then the die() call is nullified, but smatch doesn't realise that means
all paths of mydie() are __noreturn__ too.

regards
john