re PR c++/44361 (-Wunused-but-set-variable vs. explicit void cast)

	PR c++/44361
	* c-typeck.c (mark_exp_read): Handle C_MAYBE_CONST_EXPR.
	* c-parser.c (c_parser_postfix_expression): Call mark_exp_read on
	statement expression.

	* c-c++-common/Wunused-var-9.c: New test.

From-SVN: r160318

1 files changed, 80 insertions, 0 deletions

diff --git a/gcc/testsuite/c-c++-common/Wunused-var-9.c b/gcc/testsuite/c-c++-common/Wunused-var-9.c
new file mode 100644
index 0000000..b2cdc45
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/Wunused-var-9.c
@@ -0,0 +1,80 @@
+/* { dg-options "-Wunused" } */
+/* { dg-do compile } */
+
+int f1 (int *, int);
+int f2 (int *);
+int f3 (int *);
+
+int
+f4 (int x)
+{
+  int a, n = 0;
+  int b;
+  for (a = f1 (&b, x); f2 (&b); (void) (a = f3 (&b)))
+    n++;
+  return n;
+}
+
+void
+f5 (int x)
+{
+  int a;
+  a = x;
+  (void) (a = x);
+}
+
+void
+f6 (int x)
+{
+  int a;	/* { dg-warning "set but not used" } */
+  a = x;
+}
+
+void
+f7 (int x)
+{
+  int a;
+  ({ a = x; });
+}
+
+int
+f8 (int x)
+{
+  int a;
+  int b = ({ a = x; });
+  return b;
+}
+
+int v;
+
+void
+f9 (int x)
+{
+  int a;
+  ({ v++, a = x; });
+}
+
+int
+f10 (int x)
+{
+  int a;
+  int b = ({ v++, a = x; });
+  return b;
+}
+
+void
+f11 (int x)
+{
+  int a;
+  a = x;
+  ({ v++, a; });
+}
+
+int
+f12 (int x)
+{
+  int a;
+  a = x;
+  int b = ({ v++, a; });
+  return b;
+}