tests: replace fgets by xfgets

With fortification enabled, fgets calls return result needs to be checked,
has it gets the __wur macro enabled.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

assert/test-assert-perr.c

@@ -11,6 +11,8 @@
 #include <string.h>
 #include <setjmp.h>
 
+#include <support/xstdio.h>
+
 jmp_buf rec;
 char buf[160];
 
@@ -70,15 +72,15 @@ main(void)
     failed = 1; /* should not happen */
 
   rewind (stderr);
-  fgets (buf, 160, stderr);
+  xfgets (buf, 160, stderr);
   if (!strstr(buf, strerror (1)))
     failed = 1;
 
-  fgets (buf, 160, stderr);
+  xfgets (buf, 160, stderr);
   if (strstr (buf, strerror (0)))
     failed = 1;
 
-  fgets (buf, 160, stderr);
+  xfgets (buf, 160, stderr);
   if (strstr (buf, strerror (2)))
     failed = 1;
 

assert/test-assert.c

@@ -11,6 +11,8 @@
 #include <string.h>
 #include <setjmp.h>
 
+#include <support/xstdio.h>
+
 jmp_buf rec;
 char buf[160];
 
@@ -72,15 +74,15 @@ main (void)
     failed = 1; /* should not happen */
 
   rewind (stderr);
-  fgets (buf, 160, stderr);
+  xfgets (buf, 160, stderr);
   if (!strstr (buf, "1 == 2"))
     failed = 1;
 
-  fgets (buf, 160, stderr);
+  xfgets (buf, 160, stderr);
   if (strstr (buf, "1 == 1"))
     failed = 1;
 
-  fgets (buf, 160, stderr);
+  xfgets (buf, 160, stderr);
   if (strstr (buf, "2 == 3"))
     failed = 1;
 

stdio-common/test_rdwr.c

@@ -20,6 +20,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include <support/xstdio.h>
 
 int
 main (int argc, char **argv)
@@ -49,7 +50,7 @@ main (int argc, char **argv)
 
   (void) fputs (hello, f);
   rewind (f);
-  (void) fgets (buf, sizeof (buf), f);
+  xfgets (buf, sizeof (buf), f);
   rewind (f);
   (void) fputs (buf, f);
   rewind (f);
@@ -104,12 +105,8 @@ main (int argc, char **argv)
   if (!lose)
     {
       rewind (f);
-      if (fgets (buf, sizeof (buf), f) == NULL)
+      xfgets (buf, sizeof (buf), f);
-	{
+      if (strcmp (buf, replace))
-	  printf ("fgets got %s.\n", strerror(errno));
-	  lose = 1;
-	}
-      else if (strcmp (buf, replace))
 	{
 	  printf ("Read \"%s\" instead of \"%s\".\n", buf, replace);
 	  lose = 1;

support/Makefile

@@ -123,6 +123,7 @@ libsupport-routines = \
   xdup2 \
   xfchmod \
   xfclose \
+  xfgets \
   xfopen \
   xfork \
   xfread \

support/xfgets.c

@@ -0,0 +1,32 @@
+/* fgets with error checking.
+   Copyright (C) 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 <support/xstdio.h>
+
+#include <support/check.h>
+#include <stdlib.h>
+
+char *
+xfgets (char *s, int size, FILE *stream)
+{
+  char *ret = fgets (s, size, stream);
+  if (!ret && ferror(stream))
+    FAIL_EXIT1 ("fgets failed: %m");
+
+  return ret;
+}

support/xstdio.h

@@ -28,6 +28,7 @@ FILE *xfopen (const char *path, const char *mode);
 void xfclose (FILE *);
 FILE *xfreopen (const char *path, const char *mode, FILE *stream);
 void xfread (void *ptr, size_t size, size_t nmemb, FILE *stream);
+char *xfgets (char *s, int size, FILE *stream);
 
 /* Read a line from FP, using getline.  *BUFFER must be NULL, or a
    heap-allocated pointer of *LENGTH bytes.  Return the number of

sysdeps/pthread/tst-cancel6.c

@@ -20,12 +20,13 @@
 #include <stdlib.h>
 #include <unistd.h>
 
+#include <support/xstdio.h>
 
 static void *
 tf (void *arg)
 {
   char buf[100];
-  fgets (buf, sizeof (buf), arg);
+  xfgets (buf, sizeof (buf), arg);
   /* This call should never return.  */
   return NULL;
 }