Remove 'grp' and merge into 'nss' and 'posix'

The majority of grp routines are entry points for nss functionality.
This commit removes the 'grp' subdirectory and moves all nss-relevant
functionality and all tests to 'nss', and the 'setgroups' stub into
'posix' (alongside the 'getgroups' stub).  References to grp/ are
accordingly changed.  In addition, compat-initgroups.c, a fallback
implementation of initgroups is renamed to initgroups-fallback.c so that
the build system does not confuse it for nss_compat/compat-initgroups.c.

Build time improves very slightly; e.g. down from an average of 45.5s to
44.5s on an 8-thread mobile x86_64 CPU.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

1 files changed, 126 insertions, 0 deletions

diff --git a/nss/tst_fgetgrent.c b/nss/tst_fgetgrent.c
new file mode 100644
index 0000000000..be41191824
--- /dev/null
+++ b/nss/tst_fgetgrent.c
@@ -0,0 +1,126 @@
+/* Copyright (C) 1999-2023 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <grp.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+static int errors;
+
+static void
+write_users (FILE *f, int large_pos, int pos)
+{
+  int i;
+
+  if (pos == large_pos)
+    {
+      if (large_pos == 3)
+	fprintf (f, ":three");
+
+      /* we need more than 2048 bytes for proper testing.  */
+      for (i = 0; i < 500; i++)
+	fprintf (f, ",user%03d", i);
+    }
+  fprintf (f, "\n");
+
+}
+
+static void
+write_group (const char *filename, int pos)
+{
+  FILE *f;
+
+  f = fopen (filename, "w");
+  fprintf (f, "one:x:1:one");
+  write_users (f, pos, 1);
+  fprintf (f, "two:x:2:two");
+  write_users (f, pos, 2);
+  fprintf (f, "three:x:3");
+  write_users (f, pos, 3);
+  fclose (f);
+}
+
+static void
+test_entry (const char *name, gid_t gid, struct group *g)
+{
+  if (!g)
+    {
+      printf ("Error: Entry is empty\n");
+      errors++;
+      return;
+    }
+
+  if ((g->gr_gid == gid) && (strcmp (g->gr_name, name) == 0))
+    printf ("Ok: %s: %d\n", g->gr_name, g->gr_gid);
+  else
+    {
+      printf ("Error: %s: %d should be: %s: %d\n", g->gr_name, g->gr_gid,
+	      name, gid);
+      errors++;
+    }
+}
+
+
+static void
+test_fgetgrent (const char *filename)
+{
+  struct group *g;
+  FILE *f;
+
+  f = fopen (filename,"r");
+
+  g = fgetgrent (f);
+  test_entry ("one", 1, g);
+  g = fgetgrent (f);
+  test_entry ("two", 2, g);
+  g = fgetgrent (f);
+  test_entry ("three", 3, g);
+  fclose (f);
+}
+
+
+int
+main (int argc, char *argv[])
+{
+  char file[] = "/tmp/tst_fgetgrent.XXXXXX";
+  int fd = mkstemp (file);
+  if (fd == -1)
+    {
+      printf ("mkstemp failed: %m\n");
+      return 1;
+    }
+  close (fd);
+  int i = 0;
+
+  if (argc > 1)
+    i = atoi (argv[1]);
+  if (i > 3)
+    i = 3;
+  if (i)
+    printf ("Large group is group: %d\n", i);
+  else
+    printf ("Not using a large group\n");
+  write_group (file, i);
+  test_fgetgrent (file);
+
+  remove (file);
+
+  return (errors != 0);
+}