Make some tests ISO C 99 compliant.

6 files changed, 83 insertions, 17 deletions

diff --git a/tests/test-memchr.c b/tests/test-memchr.c
index ebf3cfcdc5..bf99a82edb 100644
--- a/tests/test-memchr.c
+++ b/tests/test-memchr.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2008 Free Software Foundation
+ * Copyright (C) 2008-2009 Free Software Foundation
  * Written by Eric Blake and Bruno Haible
  *
  * This program is free software: you can redistribute it and/or modify
@@ -22,6 +22,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+#include "zerosize-ptr.h"
+
 #define ASSERT(expr) \
   do									     \
     {									     \
@@ -41,8 +43,6 @@
 int
 main ()
 {
-  void *nil = NULL; /* Use to avoid gcc attribute((nonnull)) warnings.  */
-
   size_t n = 0x100000;
   char *input = malloc (n);
   ASSERT (input);
@@ -58,7 +58,7 @@ main ()
   ASSERT (MEMCHR (input, 'a', n) == input);
 
   ASSERT (MEMCHR (input, 'a', 0) == NULL);
-  ASSERT (MEMCHR (nil, 'a', 0) == NULL);
+  ASSERT (MEMCHR (zerosize_ptr (), 'a', 0) == NULL);
 
   ASSERT (MEMCHR (input, 'b', n) == input + 1);
   ASSERT (MEMCHR (input, 'c', n) == input + 2);
diff --git a/tests/test-memchr2.c b/tests/test-memchr2.c
index c804a41582..c7ba6b9735 100644
--- a/tests/test-memchr2.c
+++ b/tests/test-memchr2.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2008 Free Software Foundation
+ * Copyright (C) 2008-2009 Free Software Foundation
  * Written by Eric Blake
  *
  * This program is free software: you can redistribute it and/or modify
@@ -23,6 +23,8 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "zerosize-ptr.h"
+
 #define ASSERT(expr) \
   do									     \
     {									     \
@@ -58,7 +60,7 @@ main ()
   ASSERT (MEMCHR2 (input, 'b', 'a', n) == input);
 
   ASSERT (MEMCHR2 (input, 'a', 'b', 0) == NULL);
-  ASSERT (MEMCHR2 (NULL, 'a', 'b', 0) == NULL);
+  ASSERT (MEMCHR2 (zerosize_ptr (), 'a', 'b', 0) == NULL);
 
   ASSERT (MEMCHR2 (input, 'b', 'd', n) == input + 1);
   ASSERT (MEMCHR2 (input + 2, 'b', 'd', n - 2) == input + 1026);
diff --git a/tests/test-memcmp.c b/tests/test-memcmp.c
index 50342cb968..d108198f97 100644
--- a/tests/test-memcmp.c
+++ b/tests/test-memcmp.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2008 Free Software Foundation
+ * Copyright (C) 2008-2009 Free Software Foundation
  * Written by Simon Josefsson
  *
  * This program is free software: you can redistribute it and/or modify
@@ -22,6 +22,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+#include "zerosize-ptr.h"
+
 #define ASSERT(expr) \
   do									     \
     {									     \
@@ -37,10 +39,8 @@
 int
 main (void)
 {
-  void *nil = NULL; /* Use to avoid gcc attribute((nonnull)) warnings.  */
-
   /* Test equal / not equal distinction.  */
-  ASSERT (memcmp (nil, nil, 0) == 0);
+  ASSERT (memcmp (zerosize_ptr (), zerosize_ptr (), 0) == 0);
   ASSERT (memcmp ("foo", "foobar", 2) == 0);
   ASSERT (memcmp ("foo", "foobar", 3) == 0);
   ASSERT (memcmp ("foo", "foobar", 4) != 0);
diff --git a/tests/test-memmem.c b/tests/test-memmem.c
index e429ac096a..7f0f9257a3 100644
--- a/tests/test-memmem.c
+++ b/tests/test-memmem.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2004, 2007, 2008 Free Software Foundation
+ * Copyright (C) 2004, 2007-2009 Free Software Foundation
  * Written by Bruno Haible and Eric Blake
  *
  * This program is free software: you can redistribute it and/or modify
@@ -24,6 +24,8 @@
 #include <stdlib.h>
 #include <unistd.h>
 
+#include "zerosize-ptr.h"
+
 #define ASSERT(expr) \
   do									     \
     {									     \
@@ -78,9 +80,9 @@ main (int argc, char *argv[])
     ASSERT (result == input + 11);
   }
 
-  /* Check that length 0 does not dereference NULL.  */
+  /* Check that length 0 does not dereference the pointer.  */
   {
-    const char *result = memmem (NULL, 0, "foo", 3);
+    const char *result = memmem (zerosize_ptr (), 0, "foo", 3);
     ASSERT (result == NULL);
   }
 
diff --git a/tests/test-memrchr.c b/tests/test-memrchr.c
index f829a226ae..63568c1566 100644
--- a/tests/test-memrchr.c
+++ b/tests/test-memrchr.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2008 Free Software Foundation
+ * Copyright (C) 2008-2009 Free Software Foundation
  * Written by Eric Blake and Bruno Haible
  *
  * This program is free software: you can redistribute it and/or modify
@@ -22,6 +22,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+#include "zerosize-ptr.h"
+
 #define ASSERT(expr) \
   do									     \
     {									     \
@@ -41,8 +43,6 @@
 int
 main ()
 {
-  void *nil = NULL; /* Use to avoid gcc attribute((nonnull)) warnings.  */
-
   size_t n = 0x100000;
   char *input = malloc (n);
   ASSERT (input);
@@ -58,7 +58,7 @@ main ()
   ASSERT (MEMRCHR (input, 'a', n) == input + n - 1);
 
   ASSERT (MEMRCHR (input, 'a', 0) == NULL);
-  ASSERT (MEMRCHR (nil, 'a', 0) == NULL);
+  ASSERT (MEMRCHR (zerosize_ptr (), 'a', 0) == NULL);
 
   ASSERT (MEMRCHR (input, 'b', n) == input + n - 2);
   ASSERT (MEMRCHR (input, 'c', n) == input + n - 3);
diff --git a/tests/zerosize-ptr.h b/tests/zerosize-ptr.h
new file mode 100644
index 0000000000..fa00aeeee5
--- /dev/null
+++ b/tests/zerosize-ptr.h
@@ -0,0 +1,62 @@
+/* Return a pointer to a zero-size object in memory.
+   Copyright (C) 2009 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* ISO C 99 does not allow memcmp(), memchr() etc. to be invoked with a NULL
+   argument.  Therefore this file produces a non-NULL pointer which cannot
+   be dereferenced, if possible.  */
+
+#include <stdlib.h>
+
+#if HAVE_MPROTECT
+# include <fcntl.h>
+# include <unistd.h>
+# include <sys/types.h>
+# include <sys/mman.h>
+/* Define MAP_FILE when it isn't otherwise.  */
+# ifndef MAP_FILE
+#  define MAP_FILE 0
+# endif
+#endif
+
+/* Return a pointer to a zero-size object in memory, if possible.
+   Return NULL otherwise.  */
+
+static void *
+zerosize_ptr (void)
+{
+/* Use mmap and mprotect when they exist.  Don't test HAVE_MMAP, because it is
+   not defined on HP-UX 11 (since it does not support MAP_FIXED).  */
+#if HAVE_MPROTECT
+# if HAVE_MAP_ANONYMOUS
+  const int flags = MAP_ANONYMOUS | MAP_PRIVATE;
+  const int fd = -1;
+# else /* !HAVE_MAP_ANONYMOUS */
+  const int flags = MAP_FILE | MAP_PRIVATE;
+  int fd = open ("/dev/zero", O_RDONLY, 0666);
+  if (fd >= 0)
+# endif
+    {
+      int pagesize = getpagesize ();
+      char *two_pages =
+	(char *) mmap (NULL, 2 * pagesize, PROT_READ | PROT_WRITE,
+		       flags, fd, 0);
+      if (two_pages != (char *)(-1)
+	  && mprotect (two_pages + pagesize, pagesize, PROT_NONE) == 0)
+	return two_pages + pagesize;
+    }
+#endif
+  return NULL;
+}