testsuite: Add c23-stdarg-4.c test variant where all functions return large struct

I think we have no coverage for the case where structure_value_addr_parm and
TYPE_NO_NAMED_ARGS_STDARG_P are both true.  The
  if (type_arg_types != 0)
    n_named_args
      = (list_length (type_arg_types)
         /* Count the struct value address, if it is passed as a parm.  */
         + structure_value_addr_parm);
  else if (TYPE_NO_NAMED_ARGS_STDARG_P (funtype))
    n_named_args = 0;
  else
    /* If we know nothing, treat all args as named.  */
    n_named_args = num_actuals;
code should probably have n_named_args = structure_value_addr_parm;
instead of n_named_args = 0;, this testcase is an attempt to see if
it is broken on any target.

2024-02-28  Jakub Jelinek  <jakub@redhat.com>

	* gcc.dg/c23-stdarg-6.c: New test.

1 files changed, 217 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.dg/c23-stdarg-6.c b/gcc/testsuite/gcc.dg/c23-stdarg-6.c
new file mode 100644
index 0000000..d5f08d0
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c23-stdarg-6.c
@@ -0,0 +1,217 @@
+/* Test C23 variadic functions with no named parameters, or last named
+   parameter with a declaration not allowed in C17.  Execution tests.  */
+/* { dg-do run } */
+/* { dg-options "-std=c23 -pedantic-errors" } */
+
+#include <stdarg.h>
+
+extern void abort (void);
+extern void exit (int);
+struct s { char c[1000]; };
+
+struct s
+f (...)
+{
+  va_list ap;
+  va_start (ap);
+  double r = va_arg (ap, int);
+  r += va_arg (ap, double);
+  r += va_arg (ap, int);
+  r += va_arg (ap, double);
+  va_end (ap);
+  struct s ret = {};
+  ret.c[0] = r;
+  ret.c[999] = 42;
+  return ret;
+}
+
+struct s
+g (...)
+{
+  va_list ap;
+  va_start (ap, random ! ignored, ignored ** text);
+  for (int i = 0; i < 10; i++)
+    if (va_arg (ap, double) != i)
+      abort ();
+  va_end (ap);
+  struct s ret = {};
+  ret.c[0] = 17;
+  ret.c[999] = 58;
+  return ret;
+}
+
+struct s
+h1 (register int x, ...)
+{
+  va_list ap;
+  va_start (ap);
+  for (int i = 0; i < 10; i++)
+    {
+      if (va_arg (ap, double) != i)
+	abort ();
+      i++;
+      if (va_arg (ap, int) != i)
+	abort ();
+    }
+  va_end (ap);
+  struct s ret = {};
+  ret.c[0] = 32;
+  ret.c[999] = 95;
+  return ret;
+}
+
+struct s
+h2 (int x(), ...)
+{
+  va_list ap;
+  va_start (ap);
+  for (int i = 0; i < 10; i++)
+    {
+      if (va_arg (ap, double) != i)
+	abort ();
+      i++;
+      if (va_arg (ap, int) != i)
+	abort ();
+    }
+  va_end (ap);
+  struct s ret = {};
+  ret.c[0] = 5;
+  ret.c[999] = 125;
+  return ret;
+}
+
+struct s
+h3 (int x[10], ...)
+{
+  va_list ap;
+  va_start (ap);
+  for (int i = 0; i < 10; i++)
+    {
+      if (va_arg (ap, double) != i)
+	abort ();
+      i++;
+      if (va_arg (ap, int) != i)
+	abort ();
+    }
+  va_end (ap);
+  struct s ret = {};
+  ret.c[0] = 8;
+  ret.c[999] = 12;
+  return ret;
+}
+
+struct s
+h4 (char x, ...)
+{
+  va_list ap;
+  va_start (ap);
+  for (int i = 0; i < 10; i++)
+    {
+      if (va_arg (ap, double) != i)
+	abort ();
+      i++;
+      if (va_arg (ap, int) != i)
+	abort ();
+    }
+  va_end (ap);
+  struct s ret = {};
+  ret.c[0] = 18;
+  ret.c[999] = 28;
+  return ret;
+}
+
+struct s
+h5 (float x, ...)
+{
+  va_list ap;
+  va_start (ap);
+  for (int i = 0; i < 10; i++)
+    {
+      if (va_arg (ap, double) != i)
+	abort ();
+      i++;
+      if (va_arg (ap, int) != i)
+	abort ();
+    }
+  va_end (ap);
+  struct s ret = {};
+  ret.c[0] = 38;
+  ret.c[999] = 48;
+  return ret;
+}
+
+struct s
+h6 (volatile long x, ...)
+{
+  va_list ap;
+  va_start (ap);
+  for (int i = 0; i < 10; i++)
+    {
+      if (va_arg (ap, double) != i)
+	abort ();
+      i++;
+      if (va_arg (ap, int) != i)
+	abort ();
+    }
+  va_end (ap);
+  struct s ret = {};
+  ret.c[0] = 58;
+  ret.c[999] = 68;
+  return ret;
+}
+
+struct s
+h7 (volatile struct s x, ...)
+{
+  va_list ap;
+  va_start (ap);
+  for (int i = 0; i < 10; i++)
+    {
+      if (va_arg (ap, double) != i)
+	abort ();
+      i++;
+      if (va_arg (ap, int) != i)
+	abort ();
+    }
+  va_end (ap);
+  struct s ret = {};
+  ret.c[0] = 78;
+  ret.c[999] = 88;
+  return ret;
+}
+
+int
+main ()
+{
+  struct s x = f (1, 2.0, 3, 4.0);
+  if (x.c[0] != 10 || x.c[999] != 42)
+    abort ();
+  x = g (0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0);
+  if (x.c[0] != 17 || x.c[999] != 58)
+    abort ();
+  x = g (0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f, 9.0f);
+  if (x.c[0] != 17 || x.c[999] != 58)
+    abort ();
+  x = h1 (0, 0.0, 1, 2.0, 3, 4.0, 5, 6.0, 7, 8.0, 9);
+  if (x.c[0] != 32 || x.c[999] != 95)
+    abort ();
+  x = h2 (0, 0.0, 1, 2.0, 3, 4.0, 5, 6.0, 7, 8.0, 9);
+  if (x.c[0] != 5 || x.c[999] != 125)
+    abort ();
+  x = h3 (0, 0.0, 1, 2.0, 3, 4.0, 5, 6.0, 7, 8.0, 9);
+  if (x.c[0] != 8 || x.c[999] != 12)
+    abort ();
+  x = h4 (0, 0.0, 1, 2.0, 3, 4.0, 5, 6.0, 7, 8.0, 9);
+  if (x.c[0] != 18 || x.c[999] != 28)
+    abort ();
+  x = h5 (0, 0.0, 1, 2.0, 3, 4.0, 5, 6.0, 7, 8.0, 9);
+  if (x.c[0] != 38 || x.c[999] != 48)
+    abort ();
+  x = h6 (0, 0.0, 1, 2.0, 3, 4.0, 5, 6.0, 7, 8.0, 9);
+  if (x.c[0] != 58 || x.c[999] != 68)
+    abort ();
+  x = h7 ((struct s) {}, 0.0, 1, 2.0, 3, 4.0, 5, 6.0, 7, 8.0, 9);
+  if (x.c[0] != 78 || x.c[999] != 88)
+    abort ();
+  exit (0);
+}