Test for NULL in variable argument lists

Sometimes a vararg function receives a NULL-terminated list of pointers.
This can fail if sizeof(NULL) < sizeof(void *), as this test illustrates.

2 files changed, 53 insertions, 1 deletions

diff --git a/test/regression/Makefile b/test/regression/Makefile
index 191a2285..5d40e2c9 100644
--- a/test/regression/Makefile
+++ b/test/regression/Makefile
@@ -23,7 +23,7 @@ TESTS=int32 int64 floats floats-basics \
 TESTS_COMP=attribs1 bitfields1 bitfields2 bitfields3 bitfields4 \
   bitfields5 bitfields6 bitfields7 bitfields8 \
   builtins-$(ARCH) packedstruct1 packedstruct2 alignas \
-  varargs1 varargs2 sections alias
+  varargs1 varargs2 varargs3 sections alias
 
 # Can run, both in compiled mode and in interpreter mode,
 # but produce processor-dependent results, so no reference output in Results
diff --git a/test/regression/varargs3.c b/test/regression/varargs3.c
new file mode 100644
index 00000000..a46d81e3
--- /dev/null
+++ b/test/regression/varargs3.c
@@ -0,0 +1,52 @@
+#include <stdarg.h>
+#include <stdio.h>
+
+void initialize(int first, ...)
+{
+  va_list ap;
+  va_start(ap, first);
+  while (1) {
+    int * p = va_arg(ap, int *);
+    if (p == NULL) break;
+    *p = first;
+    first++;
+  }
+}
+
+void test(void)
+{
+  int a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q;
+  initialize(42, &a, &b, &c, &d, &e, &f, &g, &h, &i, &j,
+             &k, &l, &m, &n, &o, &p, &q, NULL);
+  printf("a = %d\n", a);
+  printf("b = %d\n", b);
+  printf("c = %d\n", c);
+  printf("d = %d\n", d);
+  printf("e = %d\n", e);
+  printf("f = %d\n", f);
+  printf("g = %d\n", g);
+  printf("h = %d\n", h);
+  printf("i = %d\n", i);
+  printf("j = %d\n", j);
+  printf("k = %d\n", k);
+  printf("l = %d\n", l);
+  printf("m = %d\n", m);
+  printf("n = %d\n", n);
+  printf("o = %d\n", o);
+  printf("p = %d\n", p);
+  printf("q = %d\n", q);
+}
+
+void wipestack(void)
+{
+  unsigned int b[100];
+  int i;
+  for (i = 0; i < 100; i++) ((volatile unsigned int *)b)[i] = 0xDEADBEEFU;
+}
+
+int main()
+{
+  wipestack();
+  test();
+  return 0;
+}