diff options
author | Russell King <rmk+lkml@arm.linux.org.uk> | 2009-06-06 22:47:11 +0100 |
---|---|---|
committer | Sam Ravnborg <sam@ravnborg.org> | 2009-06-09 22:37:57 +0200 |
commit | eedc9d83eaab2d35fb9dd1ec25b765dec964e26c (patch) | |
tree | 0ac52787334de2da7852f70a4d6822e6cb291a68 /scripts/unifdef.c | |
parent | 67b7ebe091cd92fd69f732da3170720d79c4e632 (diff) | |
download | kernel_goldelico_gta04-eedc9d83eaab2d35fb9dd1ec25b765dec964e26c.zip kernel_goldelico_gta04-eedc9d83eaab2d35fb9dd1ec25b765dec964e26c.tar.gz kernel_goldelico_gta04-eedc9d83eaab2d35fb9dd1ec25b765dec964e26c.tar.bz2 |
kbuild: fix headers_exports with boolean expression
When we had code like this in a header unifdef failed to
deduct that the expression was always false - and we had code exported
that was not intended for userspace.
#if defined(__KERNEL__) && !defined(__ASSEMBLY__)
int a;
#endif
This commit implment support in unidef which allows it to work out if
an #if expression always evaluates true or false for symbols which
are being undefined/always defined.
The patch is slightly more complicated than I'd hoped because unifdef
needs to see lines fully evaluated - doing otherwise causes it to
mark the line as "dirty" and copy it over no matter what.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Diffstat (limited to 'scripts/unifdef.c')
-rw-r--r-- | scripts/unifdef.c | 48 |
1 files changed, 37 insertions, 11 deletions
diff --git a/scripts/unifdef.c b/scripts/unifdef.c index 05a31a6..30d459f 100644 --- a/scripts/unifdef.c +++ b/scripts/unifdef.c @@ -678,8 +678,10 @@ eval_unary(const struct ops *ops, int *valp, const char **cpp) if (*cp == '!') { debug("eval%d !", ops - eval_ops); cp++; - if (eval_unary(ops, valp, &cp) == LT_IF) + if (eval_unary(ops, valp, &cp) == LT_IF) { + *cpp = cp; return (LT_IF); + } *valp = !*valp; } else if (*cp == '(') { cp++; @@ -700,13 +702,16 @@ eval_unary(const struct ops *ops, int *valp, const char **cpp) return (LT_IF); cp = skipcomment(cp); sym = findsym(cp); - if (sym < 0) - return (LT_IF); - *valp = (value[sym] != NULL); cp = skipsym(cp); cp = skipcomment(cp); if (*cp++ != ')') return (LT_IF); + if (sym >= 0) + *valp = (value[sym] != NULL); + else { + *cpp = cp; + return (LT_IF); + } keepthis = false; } else if (!endsym(*cp)) { debug("eval%d symbol", ops - eval_ops); @@ -741,11 +746,11 @@ eval_table(const struct ops *ops, int *valp, const char **cpp) const struct op *op; const char *cp; int val; + Linetype lhs, rhs; debug("eval%d", ops - eval_ops); cp = *cpp; - if (ops->inner(ops+1, valp, &cp) == LT_IF) - return (LT_IF); + lhs = ops->inner(ops+1, valp, &cp); for (;;) { cp = skipcomment(cp); for (op = ops->op; op->str != NULL; op++) @@ -755,14 +760,32 @@ eval_table(const struct ops *ops, int *valp, const char **cpp) break; cp += strlen(op->str); debug("eval%d %s", ops - eval_ops, op->str); - if (ops->inner(ops+1, &val, &cp) == LT_IF) - return (LT_IF); - *valp = op->fn(*valp, val); + rhs = ops->inner(ops+1, &val, &cp); + if (op->fn == op_and && (lhs == LT_FALSE || rhs == LT_FALSE)) { + debug("eval%d: and always false", ops - eval_ops); + if (lhs == LT_IF) + *valp = val; + lhs = LT_FALSE; + continue; + } + if (op->fn == op_or && (lhs == LT_TRUE || rhs == LT_TRUE)) { + debug("eval%d: or always true", ops - eval_ops); + if (lhs == LT_IF) + *valp = val; + lhs = LT_TRUE; + continue; + } + if (rhs == LT_IF) + lhs = LT_IF; + if (lhs != LT_IF) + *valp = op->fn(*valp, val); } *cpp = cp; debug("eval%d = %d", ops - eval_ops, *valp); - return (*valp ? LT_TRUE : LT_FALSE); + if (lhs != LT_IF) + lhs = (*valp ? LT_TRUE : LT_FALSE); + return lhs; } /* @@ -773,12 +796,15 @@ eval_table(const struct ops *ops, int *valp, const char **cpp) static Linetype ifeval(const char **cpp) { + const char *cp = *cpp; int ret; int val; debug("eval %s", *cpp); keepthis = killconsts ? false : true; - ret = eval_table(eval_ops, &val, cpp); + ret = eval_table(eval_ops, &val, &cp); + if (ret != LT_IF) + *cpp = cp; debug("eval = %d", val); return (keepthis ? LT_IF : ret); } |