@@ -2821,9 +2821,16 @@ static struct symbol *evaluate_cast(struct expression *expr)
if ((class1 & TYPE_RESTRICT) && restricted_value(target, t1))
warning(expr->pos, "cast to %s",
show_typename(t1));
- if (class2 & TYPE_RESTRICT)
- warning(expr->pos, "cast from %s",
- show_typename(t2));
+ if (class2 & TYPE_RESTRICT) {
+ if (t1 == &bool_ctype) {
+ if (class2 & TYPE_FOULED)
+ warning(expr->pos, "%s degrades to integer",
+ show_typename(t2));
+ } else {
+ warning(expr->pos, "cast from %s",
+ show_typename(t2));
+ }
+ }
}
if (t1 == &ulong_ctype)
@@ -15,7 +15,6 @@ static _Bool fstse(struct s a) { return (_Bool)a; }
* check-command: sparse $file
*
* check-error-start
-bool-cast-bad.c:9:42: warning: cast from restricted le16
bool-cast-bad.c:10:41: warning: incorrect type in return expression (different base types)
bool-cast-bad.c:10:41: expected bool
bool-cast-bad.c:10:41: got struct s a
@@ -19,8 +19,4 @@ static _Bool fres(le16 a) { return (_Bool)a; }
* check-command: test-linearize -m64 $file
* check-output-ignore
* check-output-excludes: cast\\.
- *
- * check-error-start
-bool-cast-explicit.c:15:37: warning: cast from restricted le16
- * check-error-end
*/
@@ -3,12 +3,16 @@ typedef unsigned int __attribute__((bitwise)) large_t;
_Bool lfoo(large_t x) { return x; }
_Bool qfoo(large_t x) { _Bool r = x; return r; }
+_Bool xfoo(large_t x) { return (_Bool)x; }
_Bool lbar(large_t x) { return ~x; }
_Bool qbar(large_t x) { _Bool r = ~x; return r; }
+_Bool xbar(large_t x) { return (_Bool)~x; }
_Bool lbaz(large_t x) { return !x; }
_Bool qbaz(large_t x) { _Bool r = !x; return r; }
+_Bool xbaz(large_t x) { return (_Bool)!x; }
_Bool lqux(large_t x) { return x & LBIT; }
_Bool qqux(large_t x) { _Bool r = x & LBIT; return r; }
+_Bool xqux(large_t x) { return (_Bool)(x & LBIT); }
typedef unsigned short __attribute__((bitwise)) small_t;
@@ -16,19 +20,24 @@ typedef unsigned short __attribute__((bitwise)) small_t;
_Bool sfoo(small_t x) { return x; }
_Bool tfoo(small_t x) { _Bool r = x; return r; }
+_Bool zfoo(small_t x) { return (_Bool)x; }
_Bool sbar(small_t x) { return ~x; }
_Bool tbar(small_t x) { _Bool r = ~x; return r; }
+_Bool zbar(small_t x) { return (_Bool)~x; }
_Bool sbaz(small_t x) { return !x; }
_Bool tbaz(small_t x) { _Bool r = !x; return r; }
+_Bool zbaz(small_t x) { return (_Bool)!x; }
_Bool squx(small_t x) { return x & SBIT; }
_Bool tqux(small_t x) { _Bool r = x & SBIT; return r; }
+_Bool zqux(small_t x) { return (_Bool)(x & SBIT); }
/*
* check-name: bool-cast-restricted.c
* check-command: sparse -Wno-decl $file
*
* check-error-start
-bool-cast-restricted.c:19:32: warning: restricted small_t degrades to integer
-bool-cast-restricted.c:20:35: warning: restricted small_t degrades to integer
+bool-cast-restricted.c:24:32: warning: restricted small_t degrades to integer
+bool-cast-restricted.c:25:35: warning: restricted small_t degrades to integer
+bool-cast-restricted.c:26:33: warning: restricted small_t degrades to integer
* check-error-end
*/
Conversion to bool is special in C since this conversion is essentially the result of the comparison with zero. As such, some operations which are normally unsafe to do with restricted types, like casting to an unrestricted type, are in fact safe to do when converting to bool and issuing a warning in those case is useless, confusing and causes people to add useless casts in the code in order to shut up the warning. Fix this by catching explicit 'bool <- restricted type' casts and not emit a warning like for others casts of restricted type to non-restrictes ones. Based-on-patch-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> --- evaluate.c | 13 ++++++++++--- validation/bool-cast-bad.c | 1 - validation/bool-cast-explicit.c | 4 ---- validation/bool-cast-restricted.c | 13 +++++++++++-- 4 files changed, 21 insertions(+), 10 deletions(-)