[PATCH] vfprintf: Add test case for user-defined types and format specifiers

[fweimer at redhat dot com (Florian Weimer)]

2017-06-19  Florian Weimer  <fweimer@redhat.com>

	* stdio-common/tst-vfprintf-user-type.c: New file.
	* stdio-common/Makefile (tests): Add tst-vfprintf-user-type.

diff --git a/stdio-common/Makefile b/stdio-common/Makefile
index 01a6dd0..63c9ebd 100644
--- a/stdio-common/Makefile
+++ b/stdio-common/Makefile
@@ -58,7 +58,8 @@ tests := tstscanf test_rdwr test-popen tstgetln test-fseek \
 	 scanf16 scanf17 tst-setvbuf1 tst-grouping bug23 bug24 \
 	 bug-vfprintf-nargs tst-long-dbl-fphex tst-fphex-wide tst-sprintf3 \
 	 bug25 tst-printf-round bug23-2 bug23-3 bug23-4 bug26 tst-fmemopen3 \
-	 tst-printf-bz18872 tst-vfprintf-width-prec tst-fmemopen4
+	 tst-printf-bz18872 tst-vfprintf-width-prec tst-fmemopen4 \
+	 tst-vfprintf-user-type \
 
 test-srcs = tst-unbputc tst-printf
 
diff --git a/stdio-common/tst-vfprintf-user-type.c b/stdio-common/tst-vfprintf-user-type.c
new file mode 100644
index 0000000..e9596c3
--- /dev/null
+++ b/stdio-common/tst-vfprintf-user-type.c
@@ -0,0 +1,217 @@
+/* Test for user-defined types in vfprintf.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* This test contains a printf format specifier, %P, with a custom
+   type which is a long/double pair.  If a precision is specified,
+   this indicates the number of such pairs which constitute the
+   argument.  */
+
+#include <locale.h>
+#include <printf.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <support/check.h>
+#include <support/support.h>
+#include <support/test-driver.h>
+
+/* Initialized by do_test using register_printf_type.  */
+static int user_type;
+
+struct two_argument
+{
+  long i;
+  double d;
+};
+
+static void
+my_va_arg_function (void *mem, va_list *ap)
+{
+  if (test_verbose > 0)
+    printf ("info: %s (%p) called\n", __func__, mem);
+
+  struct two_argument *pair = mem;
+  pair->i = va_arg (*ap, long);
+  pair->d = va_arg (*ap, double);
+}
+
+static int
+my_printf_function (FILE *fp, const struct printf_info *info,
+                    const void *const *args)
+{
+  if (test_verbose > 0)
+    printf ("info: %s (%p, %p, {%p}@%p) called for %%%c (prec %d)\n",
+            __func__, fp, info, args[0], args, info->spec, info->prec);
+
+  TEST_VERIFY (info->spec == 'P');
+  size_t nargs;
+  int printed;
+  if (info->prec >= 0)
+    {
+      if (fputc ('{', fp) < 0)
+        return -1;
+      nargs = info->prec;
+      printed = 1;
+    }
+  else
+    {
+      nargs = 1;
+      printed = 0;
+    }
+
+  for (size_t i = 0; i < nargs; ++i)
+    {
+      if (i != 0)
+        {
+          if (fputc (',', fp) < 0)
+            return -1;
+          ++printed;
+        }
+
+      /* NB: Triple pointer indirection.  ARGS is an array of void *,
+         and those pointers point to a pointer to the memory area
+         supplied to my_va_arg_function.  */
+      struct two_argument *pair = *(void **) args[i];
+      int ret = fprintf (fp, "(%ld, %f)", pair->i, pair->d);
+      if (ret < 0)
+        return -1;
+      printed += ret;
+    }
+  if (info->prec >= 0)
+    {
+      if (fputc ('}', fp) < 0)
+        return -1;
+      ++printed;
+    }
+  return printed;
+}
+
+static int
+my_arginfo_function (const struct printf_info *info,
+                     size_t n, int *argtypes, int *size)
+{
+  /* Avoid recursion.  */
+  if (info->spec != 'P')
+    return -1;
+  if (test_verbose > 0)
+    printf ("info: %s (%p, %zu, %p, %p) called for %%%c (prec %d)\n",
+            __func__, info, n, argtypes, size, info->spec, info->prec);
+
+  TEST_VERIFY_EXIT (n >= 1);
+  size_t nargs;
+  if (info->prec >= 0)
+    nargs = info->prec;
+  else
+    nargs = 1;
+
+  size_t to_fill = nargs;
+  if (to_fill > n)
+    to_fill = n;
+  for (size_t i = 0; i < to_fill; ++i)
+    {
+      argtypes[i] = user_type;
+      size[i] = sizeof (struct two_argument);
+    }
+  if (test_verbose > 0)
+    printf ("info:   %s return value: %zu\n", __func__, nargs);
+  return nargs;
+}
+
+static int
+do_test (void)
+{
+  user_type = register_printf_type (my_va_arg_function);
+  if (test_verbose > 0)
+    printf ("info: allocated user type: %d\n", user_type);
+  TEST_VERIFY_EXIT (user_type >= PA_LAST);
+  TEST_VERIFY_EXIT (register_printf_specifier
+                    ('P', my_printf_function, my_arginfo_function) >= 0);
+
+  /* Alias declaration for asprintf, to avoid the format string
+     attribute and the associated warning.  */
+  extern int asprintf_alias (char **, const char *, ...) __asm__ ("asprintf");
+  TEST_VERIFY (asprintf_alias == asprintf);
+  char *str = NULL;
+  TEST_VERIFY (asprintf_alias (&str, "[[%P]]", 123L, 456.0) >= 0);
+  if (test_verbose > 0)
+    printf ("info: %s\n", str);
+  TEST_VERIFY (strcmp (str, "[[(123, 456.000000)]]") == 0);
+  free (str);
+
+  str = NULL;
+  TEST_VERIFY (asprintf_alias (&str, "[[%1$P %1$P]]", 123L, 457.0) >= 0);
+  if (test_verbose > 0)
+    printf ("info: %s\n", str);
+  TEST_VERIFY (strcmp (str, "[[(123, 457.000000) (123, 457.000000)]]") == 0);
+  free (str);
+
+  str = NULL;
+  TEST_VERIFY (asprintf_alias (&str, "[[%.1P]]", 1L, 2.0) >= 0);
+  if (test_verbose > 0)
+    printf ("info: %s\n", str);
+  TEST_VERIFY (strcmp (str, "[[{(1, 2.000000)}]]") == 0);
+  free (str);
+
+  str = NULL;
+  TEST_VERIFY (asprintf_alias (&str, "[[%.2P]]", 1L, 2.0, 3L, 4.0) >= 0);
+  if (test_verbose > 0)
+    printf ("info: %s\n", str);
+  TEST_VERIFY (strcmp (str, "[[{(1, 2.000000),(3, 4.000000)}]]") == 0);
+  free (str);
+
+  str = NULL;
+  TEST_VERIFY (asprintf_alias
+               (&str, "[[%.2P | %.3P]]",
+                /* argument 1: */ 1L, 2.0, 3L, 4.0,
+                /* argument 2: */ 5L, 6.0, 7L, 8.0, 9L, 10.0)
+               >= 0);
+  if (test_verbose > 0)
+    printf ("info: %s\n", str);
+  TEST_VERIFY (strcmp (str,
+                       "[["
+                       "{(1, 2.000000),(3, 4.000000)}"
+                       " | "
+                       "{(5, 6.000000),(7, 8.000000),(9, 10.000000)}"
+                       "]]") == 0);
+  free (str);
+
+  /* The following subtest fails due to bug 21534.  */
+#if 0
+  str = NULL;
+  TEST_VERIFY (asprintf_alias
+               (&str, "[[%1$.2P | %2$.3P | %1$.2P]]",
+                /* argument 1: */ 1L, 2.0, 3L, 4.0,
+                /* argument 2: */ 5L, 6.0, 7L, 8.0, 9L, 10.0)
+               >= 0);
+  if (test_verbose > 0)
+    printf ("info: %s\n", str);
+  TEST_VERIFY (strcmp (str,
+                       "[["
+                       "{(1, 2.000000),(3, 4.000000)}"
+                       " | "
+                       "{(5, 6.000000),(7, 8.000000),(9, 10.000000)}"
+                       " | "
+                       "{(1, 2.000000),(3, 4.000000)}"
+                       "]]") == 0);
+  free (str);
+#endif
+
+  return 0;
+}
+
+#include <support/test-driver.c>