@@ -1345,6 +1345,12 @@ static int check_assignment_types(struct symbol *target, struct expression **rp,
return 1;
} else if (!(sclass & TYPE_RESTRICT))
goto Cast;
+ if (t == &bool_ctype) {
+ if (is_fouled_type(s))
+ warning((*rp)->pos, "%s degrades to integer",
+ show_typename(s->ctype.base_type));
+ goto Cast;
+ }
*typediff = "different base types";
return 0;
}
@@ -15,9 +15,6 @@ static _Bool fstse(struct s a) { return (_Bool)a; }
* check-command: sparse $file
*
* check-error-start
-bool-cast-bad.c:8:41: warning: incorrect type in return expression (different base types)
-bool-cast-bad.c:8:41: expected bool
-bool-cast-bad.c:8:41: got restricted le16 [usertype] a
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
@@ -21,8 +21,5 @@ static _Bool fres(le16 a) { return a; }
* check-output-excludes: cast\\.
*
* check-error-start
-bool-cast-implicit.c:15:36: warning: incorrect type in return expression (different base types)
-bool-cast-implicit.c:15:36: expected bool
-bool-cast-implicit.c:15:36: got restricted le16 [usertype] a
* check-error-end
*/
new file mode 100644
@@ -0,0 +1,34 @@
+typedef unsigned int __attribute__((bitwise)) large_t;
+#define LBIT ((__attribute__((force)) large_t) 1)
+
+_Bool lfoo(large_t x) { return x; }
+_Bool qfoo(large_t x) { _Bool r = x; return r; }
+_Bool lbar(large_t x) { return ~x; }
+_Bool qbar(large_t x) { _Bool r = ~x; return r; }
+_Bool lbaz(large_t x) { return !x; }
+_Bool qbaz(large_t x) { _Bool r = !x; return r; }
+_Bool lqux(large_t x) { return x & LBIT; }
+_Bool qqux(large_t x) { _Bool r = x & LBIT; return r; }
+
+
+typedef unsigned short __attribute__((bitwise)) small_t;
+#define SBIT ((__attribute__((force)) small_t) 1)
+
+_Bool sfoo(small_t x) { return x; }
+_Bool tfoo(small_t x) { _Bool r = x; return r; }
+_Bool sbar(small_t x) { return ~x; }
+_Bool tbar(small_t x) { _Bool r = ~x; return r; }
+_Bool sbaz(small_t x) { return !x; }
+_Bool tbaz(small_t x) { _Bool r = !x; return r; }
+_Bool squx(small_t x) { return x & SBIT; }
+_Bool tqux(small_t x) { _Bool r = x & SBIT; return r; }
+
+/*
+ * 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
+ * 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 implicit 'bool <- restricted type' casts and not emit a warning like for others casts of restricted type to non-restrictes ones. Originally-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> --- evaluate.c | 6 ++++++ validation/bool-cast-bad.c | 3 --- validation/bool-cast-implicit.c | 3 --- validation/bool-cast-restricted.c | 34 ++++++++++++++++++++++++++++++++++ 4 files changed, 40 insertions(+), 6 deletions(-) create mode 100644 validation/bool-cast-restricted.c