a) qualifiers are joined (const int * / volatile int * -> const volatile int *)
b) pointer to void / pointer to T => pointer to void (with all qualifiers)
testcase added
Still missing: T1 * / T2 * => pointer to composite type of T1 and T2
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
evaluate.c | 82 ++++++++++++++++++++++++++++-------------------
validation/cond_expr2.c | 23 +++++++++++++
2 files changed, 72 insertions(+), 33 deletions(-)
create mode 100644 validation/cond_expr2.c
diff --git a/evaluate.c b/evaluate.c
index d505007..9f543fe 100644
--- a/evaluate.c
+++ b/evaluate.c
@@ -1070,31 +1070,6 @@ OK:
}
/*
- * FIXME!! This should do casts, array degeneration etc..
- */
-static struct symbol *compatible_ptr_type(struct expression *left, struct expression *right)
-{
- struct symbol *ltype = left->ctype, *rtype = right->ctype;
-
- if (ltype->type == SYM_NODE)
- ltype = ltype->ctype.base_type;
-
- if (rtype->type == SYM_NODE)
- rtype = rtype->ctype.base_type;
-
- if (ltype->type == SYM_PTR) {
- if (rtype->ctype.base_type == &void_ctype)
- return ltype;
- }
-
- if (rtype->type == SYM_PTR) {
- if (ltype->ctype.base_type == &void_ctype)
- return rtype;
- }
- return NULL;
-}
-
-/*
* NOTE! The degenerate case of "x ? : y", where we don't
* have a true case, this will possibly promote "x" to the
* same type as "y", and thus _change_ the conditional
@@ -1104,9 +1079,10 @@ static struct symbol *compatible_ptr_type(struct expression *left, struct expres
static struct symbol *evaluate_conditional_expression(struct expression *expr)
{
struct expression **true;
- struct symbol *ctype, *ltype, *rtype;
+ struct symbol *ctype, *ltype, *rtype, *lbase, *rbase;
int lclass, rclass;
const char * typediff;
+ int qual;
if (!evaluate_conditional(expr->conditional, 0))
return NULL;
@@ -1141,9 +1117,11 @@ static struct symbol *evaluate_conditional_expression(struct expression *expr)
expr->cond_false = cast_to(expr->cond_false, ctype);
goto out;
}
+
if ((lclass | rclass) & TYPE_PTR) {
int is_null1 = is_null_pointer_constant(*true);
int is_null2 = is_null_pointer_constant(expr->cond_false);
+
if (is_null1 && is_null2) {
*true = cast_to(*true, &ptr_ctype);
expr->cond_false = cast_to(expr->cond_false, &ptr_ctype);
@@ -1169,15 +1147,42 @@ static struct symbol *evaluate_conditional_expression(struct expression *expr)
goto Err;
}
/* OK, it's pointer on pointer */
- /* XXX - we need to handle qualifiers */
- ctype = compatible_ptr_type(*true, expr->cond_false);
- if (ctype)
- goto out;
+ if (ltype->ctype.as != rtype->ctype.as) {
+ typediff = "different address spaces";
+ goto Err;
+ }
+
+ /* need to be lazier here */
+ lbase = get_base_type(ltype);
+ rbase = get_base_type(rtype);
+ qual = ltype->ctype.modifiers | rtype->ctype.modifiers;
+ qual &= MOD_CONST | MOD_VOLATILE;
+
+ if (lbase == &void_ctype) {
+ /* XXX: pointers to function should warn here */
+ ctype = ltype;
+ goto Qual;
+
+ }
+ if (rbase == &void_ctype) {
+ /* XXX: pointers to function should warn here */
+ ctype = rtype;
+ goto Qual;
+ }
+ /* XXX: that should be pointer to composite */
+ ctype = ltype;
+ typediff = type_difference(lbase, rbase, MOD_IGN, MOD_IGN);
+ if (!typediff)
+ goto Qual;
+ goto Err;
}
- ctype = ltype;
- typediff = type_difference(ltype, rtype, MOD_IGN, MOD_IGN);
- if (!typediff)
+
+ /* void on void, struct on same struct, union on same union */
+ if (ltype == rtype) {
+ ctype = ltype;
goto out;
+ }
+ typediff = "different base types";
Err:
expression_error(expr, "incompatible types in conditional expression (%s)", typediff);
@@ -1186,6 +1191,17 @@ Err:
out:
expr->ctype = ctype;
return ctype;
+
+Qual:
+ if (qual & ~ctype->ctype.modifiers) {
+ struct symbol *sym = alloc_symbol(ctype->pos, SYM_PTR);
+ *sym = *ctype;
+ sym->ctype.modifiers |= qual;
+ ctype = sym;
+ }
+ *true = cast_to(*true, ctype);
+ expr->cond_false = cast_to(expr->cond_false, ctype);
+ goto out;
}
/* FP assignments can not do modulo or bit operations */
diff --git a/validation/cond_expr2.c b/validation/cond_expr2.c
new file mode 100644
index 0000000..e53cd13
--- /dev/null
+++ b/validation/cond_expr2.c
@@ -0,0 +1,23 @@
+extern const int *p;
+extern volatile void *q;
+extern volatile int *r;
+static void f(void)
+{
+ q = 1 ? p : q; // warn: const volatile void * -> const int *
+ r = 1 ? r : q; // OK: volatile void * -> volatile int *
+ r = 1 ? r : p; // warn: const volatile int * -> volatile int *
+}
+/*
+ * check-name: type of conditional expression
+ * check-description: Used to miss qualifier mixing and mishandle void *
+ * check-command: sparse $file
+ *
+ * check-output-start
+cond_expr2.c:6:4: warning: incorrect type in assignment (different modifiers)
+cond_expr2.c:6:4: expected void volatile *extern [addressable] [toplevel] q
+cond_expr2.c:6:4: got void const volatile *
+cond_expr2.c:8:4: warning: incorrect type in assignment (different modifiers)
+cond_expr2.c:8:4: expected int volatile *extern [addressable] [toplevel] [assigned] r
+cond_expr2.c:8:4: got int const volatile *
+ * check-output-end
+ */
--
1.5.0-rc2.GIT
-
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