According to 6.6(9), the member access operators "." and "->" may be used
in the creation of address constants.
Uses of both operators amount to the creation of EXPR_DEREF expressions
which are eventually fed into evaluate_offset() at evaluation.
Make evaluate_offset() propagate any address constant flag of the object
containing the referenced member to the newly created pointer addition
expression.
Signed-off-by: Nicolai Stange <nicstange@xxxxxxxxx>
---
evaluate.c | 6 ++++++
validation/constexpr-addr-of-static-member.c | 26 ++++++++++++++++++++++++++
2 files changed, 32 insertions(+)
create mode 100644 validation/constexpr-addr-of-static-member.c
diff --git a/evaluate.c b/evaluate.c
index 16b4ce0..f31ba9c 100644
--- a/evaluate.c
+++ b/evaluate.c
@@ -1957,6 +1957,12 @@ static struct expression *evaluate_offset(struct expression *expr, unsigned long
* we ever take the address of this member dereference..
*/
add->ctype = &lazy_ptr_ctype;
+ /*
+ * The resulting address of a member access through an address
+ * constant is an address constant again [6.6(9)].
+ */
+ add->constexpr_flags = expr->constexpr_flags;
+
return add;
}
diff --git a/validation/constexpr-addr-of-static-member.c b/validation/constexpr-addr-of-static-member.c
new file mode 100644
index 0000000..f944f21
--- /dev/null
+++ b/validation/constexpr-addr-of-static-member.c
@@ -0,0 +1,26 @@
+struct A {
+ int a;
+ int b[2];
+};
+
+struct B {
+ int c;
+ struct A d;
+};
+
+static struct B a= {1, {1, {1, 1}}};
+
+static int *b = &a.d.a; // OK
+static int *c = &(&a.d)->a; // OK
+static int *d = a.d.b; // OK
+static int *e = (&a.d)->b; // OK
+static int *f = &a.d.b[1]; // OK
+static int *g = &(&a.d)->b[1]; // OK
+
+/*
+ * check-name: address of static object's member constness verification.
+ * check-command: sparse -Wconstexpr-not-const $file
+ *
+ * check-error-start
+ * check-error-end
+ */
--
2.7.0
--
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