Here is a patch to drop qualifiers in assignment expressions.
-- Martin
C: Drop qualifiers of assignment expressions. [PR98047]
ISO C17 6.5.15.1 specifies that the result is the
type the LHS would have after lvalue conversion.
2020-12-12 Martin Uecker
gcc/c/
PR c/98047
* c-typeck.c (build_modify_expr): Drop qualifiers.
gcc/testsuite/
PR c/98047
* gcc.dg/qual-assign-7.c.c: New test.
diff --git a/gcc/c/c-typeck.c b/gcc/c/c-typeck.c
index 138af073925..d8b2ca12766 100644
--- a/gcc/c/c-typeck.c
+++ b/gcc/c/c-typeck.c
@@ -6276,16 +6276,9 @@ build_modify_expr (location_t location, tree lhs, tree
lhs_origtype,
"enum conversion in assignment is invalid in C++");
}
- /* If the lhs is atomic, remove that qualifier. */
- if (is_atomic_op)
-{
- lhstype = build_qualified_type (lhstype,
- (TYPE_QUALS (lhstype)
- & ~TYPE_QUAL_ATOMIC));
- olhstype = build_qualified_type (olhstype,
- (TYPE_QUALS (lhstype)
- & ~TYPE_QUAL_ATOMIC));
-}
+ /* Remove qualifiers. */
+ lhstype = build_qualified_type (lhstype, TYPE_UNQUALIFIED);
+ olhstype = build_qualified_type (olhstype, TYPE_UNQUALIFIED);
/* Convert new value to destination type. Fold it first, then
restore any excess precision information, for the sake of
diff --git a/gcc/testsuite/gcc.dg/qual-assign-7.c
b/gcc/testsuite/gcc.dg/qual-assign-7.c
new file mode 100644
index 000..3e064e82f5f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/qual-assign-7.c
@@ -0,0 +1,18 @@
+/* test that assignment drops qualifiers, Bug 98047 */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+
+volatile int jv;
+extern int j;
+extern typeof(jv = 1) j;
+
+_Atomic int ja;
+extern typeof(ja = 1) j;
+
+int * __restrict pa;
+extern int *p;
+extern typeof(pa = 0) p;
+
+
+
