aclocal.m4: New file with new test libiberty_AC_FUNC_STRNCMP.

	* aclocal.m4: New file with new test libiberty_AC_FUNC_STRNCMP.

	* configure.in (AC_CHECK_HEADERS): Add sys/mman.h fcntl.h.
	(libiberty_AC_FUNC_STRNCMP): Invoke.

	* strncmp.c: New file.

From-SVN: r33498

6 files changed, 479 insertions, 2 deletions

diff --git a/libiberty/ChangeLog b/libiberty/ChangeLog
index 01168d81b3d..b71886dc58c 100644
--- a/libiberty/ChangeLog
+++ b/libiberty/ChangeLog
@@ -1,3 +1,12 @@
+2000-04-27  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
+
+	* aclocal.m4: New file with new test libiberty_AC_FUNC_STRNCMP.
+
+	* configure.in (AC_CHECK_HEADERS): Add sys/mman.h fcntl.h.
+	(libiberty_AC_FUNC_STRNCMP): Invoke.
+
+	* strncmp.c: New file.
+
 Thu Apr 27 16:58:43 MET DST 2000  Jan Hubicka  <jh@suse.cz>
 
 	* hashtab.c (htab_expand): Add prototype.
diff --git a/libiberty/aclocal.m4 b/libiberty/aclocal.m4
new file mode 100644
index 00000000000..b6a38d60522
--- /dev/null
+++ b/libiberty/aclocal.m4
@@ -0,0 +1,71 @@
+dnl See whether strncmp reads past the end of its string parameters.
+dnl On some versions of SunOS4 at least, strncmp reads a word at a time
+dnl but erroneously reads past the end of strings.  This can cause
+dnl a SEGV in some cases.
+AC_DEFUN(libiberty_AC_FUNC_STRNCMP,
+[AC_REQUIRE([AC_FUNC_MMAP])
+AC_CACHE_CHECK([for working strncmp], ac_cv_func_strncmp_works,
+[AC_TRY_RUN([
+/* Test by Jim Wilson and Kaveh Ghazi.
+   Check whether strncmp reads past the end of its string parameters. */
+#include <sys/types.h>
+
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+
+#ifdef HAVE_SYS_MMAN_H
+#include <sys/mman.h>
+#endif
+
+#ifndef MAP_ANON
+#ifdef MAP_ANONYMOUS
+#define MAP_ANON MAP_ANONYMOUS
+#else
+#define MAP_ANON MAP_FILE
+#endif
+#endif
+
+#ifndef MAP_FILE
+#define MAP_FILE 0
+#endif
+#ifndef O_RDONLY
+#define O_RDONLY 0
+#endif
+
+#define MAP_LEN 0x10000
+
+main ()
+{
+#if defined(HAVE_MMAP) || defined(HAVE_MMAP_ANYWHERE)
+  char *p;
+  int dev_zero;
+
+  dev_zero = open ("/dev/zero", O_RDONLY);
+  if (dev_zero < 0)
+    exit (1);
+  
+  p = (char *) mmap (0, MAP_LEN, PROT_READ|PROT_WRITE,
+		     MAP_ANON|MAP_PRIVATE, dev_zero, 0);
+  if (p == (char *)-1)
+    exit (2);
+  else
+    {
+      char *string = "__si_type_info";
+      char *q = (char *) p + MAP_LEN - strlen (string) - 2;
+      char *r = (char *) p + 0xe;
+
+      strcpy (q, string);
+      strcpy (r, string);
+      strncmp (r, q, 14);
+    }
+#endif /* HAVE_MMAP || HAVE_MMAP_ANYWHERE */
+  exit (0);
+}
+], ac_cv_func_strncmp_works=yes, ac_cv_func_strncmp_works=no,
+  ac_cv_func_strncmp_works=no)
+rm -f core core.* *.core])
+if test $ac_cv_func_strncmp_works = no ; then
+  LIBOBJS="$LIBOBJS strncmp.o"
+fi
+])
diff --git a/libiberty/config.in b/libiberty/config.in
index 6e64208da92..bc0c7291a8c 100644
--- a/libiberty/config.in
+++ b/libiberty/config.in
@@ -13,6 +13,9 @@
 /* Define if you have <alloca.h> and it should be used (not on Ultrix).  */
 #undef HAVE_ALLOCA_H
 
+/* Define if you have a working `mmap' system call.  */
+#undef HAVE_MMAP
+
 /* Define if you have <sys/wait.h> that is POSIX.1 compatible.  */
 #undef HAVE_SYS_WAIT_H
 
@@ -196,6 +199,9 @@
 /* Define if you have the waitpid function.  */
 #undef HAVE_WAITPID
 
+/* Define if you have the <fcntl.h> header file.  */
+#undef HAVE_FCNTL_H
+
 /* Define if you have the <stdlib.h> header file.  */
 #undef HAVE_STDLIB_H
 
@@ -208,6 +214,9 @@
 /* Define if you have the <sys/file.h> header file.  */
 #undef HAVE_SYS_FILE_H
 
+/* Define if you have the <sys/mman.h> header file.  */
+#undef HAVE_SYS_MMAN_H
+
 /* Define if you have the <sys/param.h> header file.  */
 #undef HAVE_SYS_PARAM_H
 
diff --git a/libiberty/configure b/libiberty/configure
index 02c826d929e..891c656ebc4 100755
--- a/libiberty/configure
+++ b/libiberty/configure
@@ -1058,7 +1058,7 @@ else
 fi
 echo "$ac_t""$CPP" 1>&6
 
-for ac_hdr in sys/file.h sys/param.h stdlib.h string.h unistd.h strings.h sys/time.h sys/resource.h sys/stat.h
+for ac_hdr in sys/file.h sys/param.h stdlib.h string.h unistd.h strings.h sys/time.h sys/resource.h sys/stat.h sys/mman.h fcntl.h
 do
 ac_safe=`echo "$ac_hdr" | sed 'y%./+-%__p_%'`
 echo $ac_n "checking for $ac_hdr""... $ac_c" 1>&6
@@ -2550,6 +2550,364 @@ done
 
 fi
 
+for ac_hdr in unistd.h
+do
+ac_safe=`echo "$ac_hdr" | sed 'y%./+-%__p_%'`
+echo $ac_n "checking for $ac_hdr""... $ac_c" 1>&6
+echo "configure:2558: checking for $ac_hdr" >&5
+if eval "test \"`echo '$''{'ac_cv_header_$ac_safe'+set}'`\" = set"; then
+  echo $ac_n "(cached) $ac_c" 1>&6
+else
+  cat > conftest.$ac_ext <<EOF
+#line 2563 "configure"
+#include "confdefs.h"
+#include <$ac_hdr>
+EOF
+ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
+{ (eval echo configure:2568: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
+ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
+if test -z "$ac_err"; then
+  rm -rf conftest*
+  eval "ac_cv_header_$ac_safe=yes"
+else
+  echo "$ac_err" >&5
+  echo "configure: failed program was:" >&5
+  cat conftest.$ac_ext >&5
+  rm -rf conftest*
+  eval "ac_cv_header_$ac_safe=no"
+fi
+rm -f conftest*
+fi
+if eval "test \"`echo '$ac_cv_header_'$ac_safe`\" = yes"; then
+  echo "$ac_t""yes" 1>&6
+    ac_tr_hdr=HAVE_`echo $ac_hdr | sed 'y%abcdefghijklmnopqrstuvwxyz./-%ABCDEFGHIJKLMNOPQRSTUVWXYZ___%'`
+  cat >> confdefs.h <<EOF
+#define $ac_tr_hdr 1
+EOF
+ 
+else
+  echo "$ac_t""no" 1>&6
+fi
+done
+
+for ac_func in getpagesize
+do
+echo $ac_n "checking for $ac_func""... $ac_c" 1>&6
+echo "configure:2597: checking for $ac_func" >&5
+if eval "test \"`echo '$''{'ac_cv_func_$ac_func'+set}'`\" = set"; then
+  echo $ac_n "(cached) $ac_c" 1>&6
+else
+  cat > conftest.$ac_ext <<EOF
+#line 2602 "configure"
+#include "confdefs.h"
+/* System header to define __stub macros and hopefully few prototypes,
+    which can conflict with char $ac_func(); below.  */
+#include <assert.h>
+/* Override any gcc2 internal prototype to avoid an error.  */
+/* We use char because int might match the return type of a gcc2
+    builtin and then its argument prototype would still apply.  */
+char $ac_func();
+
+int main() {
+
+/* The GNU C library defines this for functions which it implements
+    to always fail with ENOSYS.  Some functions are actually named
+    something starting with __ and the normal name is an alias.  */
+#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+choke me
+#else
+$ac_func();
+#endif
+
+; return 0; }
+EOF
+if { (eval echo configure:2625: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+  rm -rf conftest*
+  eval "ac_cv_func_$ac_func=yes"
+else
+  echo "configure: failed program was:" >&5
+  cat conftest.$ac_ext >&5
+  rm -rf conftest*
+  eval "ac_cv_func_$ac_func=no"
+fi
+rm -f conftest*
+fi
+
+if eval "test \"`echo '$ac_cv_func_'$ac_func`\" = yes"; then
+  echo "$ac_t""yes" 1>&6
+    ac_tr_func=HAVE_`echo $ac_func | tr 'abcdefghijklmnopqrstuvwxyz' 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'`
+  cat >> confdefs.h <<EOF
+#define $ac_tr_func 1
+EOF
+ 
+else
+  echo "$ac_t""no" 1>&6
+fi
+done
+
+echo $ac_n "checking for working mmap""... $ac_c" 1>&6
+echo "configure:2650: checking for working mmap" >&5
+if eval "test \"`echo '$''{'ac_cv_func_mmap_fixed_mapped'+set}'`\" = set"; then
+  echo $ac_n "(cached) $ac_c" 1>&6
+else
+  if test "$cross_compiling" = yes; then
+  ac_cv_func_mmap_fixed_mapped=no
+else
+  cat > conftest.$ac_ext <<EOF
+#line 2658 "configure"
+#include "confdefs.h"
+
+/* Thanks to Mike Haertel and Jim Avera for this test.
+   Here is a matrix of mmap possibilities:
+	mmap private not fixed
+	mmap private fixed at somewhere currently unmapped
+	mmap private fixed at somewhere already mapped
+	mmap shared not fixed
+	mmap shared fixed at somewhere currently unmapped
+	mmap shared fixed at somewhere already mapped
+   For private mappings, we should verify that changes cannot be read()
+   back from the file, nor mmap's back from the file at a different
+   address.  (There have been systems where private was not correctly
+   implemented like the infamous i386 svr4.0, and systems where the
+   VM page cache was not coherent with the filesystem buffer cache
+   like early versions of FreeBSD and possibly contemporary NetBSD.)
+   For shared mappings, we should conversely verify that changes get
+   propogated back to all the places they're supposed to be.
+
+   Grep wants private fixed already mapped.
+   The main things grep needs to know about mmap are:
+   * does it exist and is it safe to write into the mmap'd area
+   * how to use it (BSD variants)  */
+#include <sys/types.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+
+/* This mess was copied from the GNU getpagesize.h.  */
+#ifndef HAVE_GETPAGESIZE
+# ifdef HAVE_UNISTD_H
+#  include <unistd.h>
+# endif
+
+/* Assume that all systems that can run configure have sys/param.h.  */
+# ifndef HAVE_SYS_PARAM_H
+#  define HAVE_SYS_PARAM_H 1
+# endif
+
+# ifdef _SC_PAGESIZE
+#  define getpagesize() sysconf(_SC_PAGESIZE)
+# else /* no _SC_PAGESIZE */
+#  ifdef HAVE_SYS_PARAM_H
+#   include <sys/param.h>
+#   ifdef EXEC_PAGESIZE
+#    define getpagesize() EXEC_PAGESIZE
+#   else /* no EXEC_PAGESIZE */
+#    ifdef NBPG
+#     define getpagesize() NBPG * CLSIZE
+#     ifndef CLSIZE
+#      define CLSIZE 1
+#     endif /* no CLSIZE */
+#    else /* no NBPG */
+#     ifdef NBPC
+#      define getpagesize() NBPC
+#     else /* no NBPC */
+#      ifdef PAGESIZE
+#       define getpagesize() PAGESIZE
+#      endif /* PAGESIZE */
+#     endif /* no NBPC */
+#    endif /* no NBPG */
+#   endif /* no EXEC_PAGESIZE */
+#  else /* no HAVE_SYS_PARAM_H */
+#   define getpagesize() 8192	/* punt totally */
+#  endif /* no HAVE_SYS_PARAM_H */
+# endif /* no _SC_PAGESIZE */
+
+#endif /* no HAVE_GETPAGESIZE */
+
+#ifdef __cplusplus
+extern "C" { void *malloc(unsigned); }
+#else
+char *malloc();
+#endif
+
+int
+main()
+{
+	char *data, *data2, *data3;
+	int i, pagesize;
+	int fd;
+
+	pagesize = getpagesize();
+
+	/*
+	 * First, make a file with some known garbage in it.
+	 */
+	data = malloc(pagesize);
+	if (!data)
+		exit(1);
+	for (i = 0; i < pagesize; ++i)
+		*(data + i) = rand();
+	umask(0);
+	fd = creat("conftestmmap", 0600);
+	if (fd < 0)
+		exit(1);
+	if (write(fd, data, pagesize) != pagesize)
+		exit(1);
+	close(fd);
+
+	/*
+	 * Next, try to mmap the file at a fixed address which
+	 * already has something else allocated at it.  If we can,
+	 * also make sure that we see the same garbage.
+	 */
+	fd = open("conftestmmap", O_RDWR);
+	if (fd < 0)
+		exit(1);
+	data2 = malloc(2 * pagesize);
+	if (!data2)
+		exit(1);
+	data2 += (pagesize - ((int) data2 & (pagesize - 1))) & (pagesize - 1);
+	if (data2 != mmap(data2, pagesize, PROT_READ | PROT_WRITE,
+	    MAP_PRIVATE | MAP_FIXED, fd, 0L))
+		exit(1);
+	for (i = 0; i < pagesize; ++i)
+		if (*(data + i) != *(data2 + i))
+			exit(1);
+
+	/*
+	 * Finally, make sure that changes to the mapped area
+	 * do not percolate back to the file as seen by read().
+	 * (This is a bug on some variants of i386 svr4.0.)
+	 */
+	for (i = 0; i < pagesize; ++i)
+		*(data2 + i) = *(data2 + i) + 1;
+	data3 = malloc(pagesize);
+	if (!data3)
+		exit(1);
+	if (read(fd, data3, pagesize) != pagesize)
+		exit(1);
+	for (i = 0; i < pagesize; ++i)
+		if (*(data + i) != *(data3 + i))
+			exit(1);
+	close(fd);
+	unlink("conftestmmap");
+	exit(0);
+}
+
+EOF
+if { (eval echo configure:2798: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext} && (./conftest; exit) 2>/dev/null
+then
+  ac_cv_func_mmap_fixed_mapped=yes
+else
+  echo "configure: failed program was:" >&5
+  cat conftest.$ac_ext >&5
+  rm -fr conftest*
+  ac_cv_func_mmap_fixed_mapped=no
+fi
+rm -fr conftest*
+fi
+
+fi
+
+echo "$ac_t""$ac_cv_func_mmap_fixed_mapped" 1>&6
+if test $ac_cv_func_mmap_fixed_mapped = yes; then
+  cat >> confdefs.h <<\EOF
+#define HAVE_MMAP 1
+EOF
+
+fi
+
+
+echo $ac_n "checking for working strncmp""... $ac_c" 1>&6
+echo "configure:2822: checking for working strncmp" >&5
+if eval "test \"`echo '$''{'ac_cv_func_strncmp_works'+set}'`\" = set"; then
+  echo $ac_n "(cached) $ac_c" 1>&6
+else
+  if test "$cross_compiling" = yes; then
+  ac_cv_func_strncmp_works=no
+else
+  cat > conftest.$ac_ext <<EOF
+#line 2830 "configure"
+#include "confdefs.h"
+
+/* Test by Jim Wilson and Kaveh Ghazi.
+   Check whether strncmp reads past the end of its string parameters. */
+#include <sys/types.h>
+
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+
+#ifdef HAVE_SYS_MMAN_H
+#include <sys/mman.h>
+#endif
+
+#ifndef MAP_ANON
+#ifdef MAP_ANONYMOUS
+#define MAP_ANON MAP_ANONYMOUS
+#else
+#define MAP_ANON MAP_FILE
+#endif
+#endif
+
+#ifndef MAP_FILE
+#define MAP_FILE 0
+#endif
+#ifndef O_RDONLY
+#define O_RDONLY 0
+#endif
+
+#define MAP_LEN 0x10000
+
+main ()
+{
+#if defined(HAVE_MMAP) || defined(HAVE_MMAP_ANYWHERE)
+  char *p;
+  int dev_zero;
+
+  dev_zero = open ("/dev/zero", O_RDONLY);
+  if (dev_zero < 0)
+    exit (1);
+  
+  p = (char *) mmap (0, MAP_LEN, PROT_READ|PROT_WRITE,
+		     MAP_ANON|MAP_PRIVATE, dev_zero, 0);
+  if (p == (char *)-1)
+    exit (2);
+  else
+    {
+      char *string = "__si_type_info";
+      char *q = (char *) p + MAP_LEN - strlen (string) - 2;
+      char *r = (char *) p + 0xe;
+
+      strcpy (q, string);
+      strcpy (r, string);
+      strncmp (r, q, 14);
+    }
+#endif /* HAVE_MMAP || HAVE_MMAP_ANYWHERE */
+  exit (0);
+}
+
+EOF
+if { (eval echo configure:2891: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext} && (./conftest; exit) 2>/dev/null
+then
+  ac_cv_func_strncmp_works=yes
+else
+  echo "configure: failed program was:" >&5
+  cat conftest.$ac_ext >&5
+  rm -fr conftest*
+  ac_cv_func_strncmp_works=no
+fi
+rm -fr conftest*
+fi
+
+rm -f core core.* *.core
+fi
+
+echo "$ac_t""$ac_cv_func_strncmp_works" 1>&6
+if test $ac_cv_func_strncmp_works = no ; then
+  LIBOBJS="$LIBOBJS strncmp.o"
+fi
+
+
 # Install a library built with a cross compiler in $(tooldir) rather
 # than $(libdir).
 if test -z "${with_cross_host}"; then
diff --git a/libiberty/configure.in b/libiberty/configure.in
index cc1b2c2082b..0814ae32967 100644
--- a/libiberty/configure.in
+++ b/libiberty/configure.in
@@ -109,7 +109,7 @@ AC_SUBST_FILE(host_makefile_frag)
 # It's OK to check for header files.  Although the compiler may not be
 # able to link anything, it had better be able to at least compile
 # something.
-AC_CHECK_HEADERS(sys/file.h sys/param.h stdlib.h string.h unistd.h strings.h sys/time.h sys/resource.h sys/stat.h)
+AC_CHECK_HEADERS(sys/file.h sys/param.h stdlib.h string.h unistd.h strings.h sys/time.h sys/resource.h sys/stat.h sys/mman.h fcntl.h)
 AC_HEADER_SYS_WAIT
 
 # This is the list of functions which libiberty will provide if they
@@ -352,6 +352,8 @@ EOF
   AC_CHECK_FUNCS($checkfuncs)
 fi
 
+libiberty_AC_FUNC_STRNCMP
+
 # Install a library built with a cross compiler in $(tooldir) rather
 # than $(libdir).
 if test -z "${with_cross_host}"; then
diff --git a/libiberty/strncmp.c b/libiberty/strncmp.c
new file mode 100644
index 00000000000..b3b9de16b10
--- /dev/null
+++ b/libiberty/strncmp.c
@@ -0,0 +1,28 @@
+/* strncmp -- compare two strings, stop after n bytes.
+   This function is in the public domain.  */
+
+#include <ansidecl.h>
+#ifdef __STDC__
+#include <stddef.h>
+#else
+#define size_t unsigned long
+#endif
+
+int
+strncmp(s1, s2, n)
+     const char *s1, *s2;
+     register size_t n;
+{
+  register unsigned char u1, u2;
+
+  while (n-- > 0)
+    {
+      u1 = (unsigned char) *s1++;
+      u2 = (unsigned char) *s2++;
+      if (u1 != u2)
+	return u1 - u2;
+      if (u1 == '\0')
+	return 0;
+    }
+  return 0;
+}