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authorRussell King <rmk+lkml@arm.linux.org.uk>2009-06-06 22:47:11 +0100
committerSam Ravnborg <sam@ravnborg.org>2009-06-09 22:37:57 +0200
commiteedc9d83eaab2d35fb9dd1ec25b765dec964e26c (patch)
tree0ac52787334de2da7852f70a4d6822e6cb291a68 /scripts/unifdef.c
parent67b7ebe091cd92fd69f732da3170720d79c4e632 (diff)
downloadlinux-linaro-eedc9d83eaab2d35fb9dd1ec25b765dec964e26c.tar.gz
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.c48
1 files changed, 37 insertions, 11 deletions
diff --git a/scripts/unifdef.c b/scripts/unifdef.c
index 05a31a6c7e1..30d459fb070 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);
}