Re: [gfortran] patch for unlink on open files

[FX Coudert <fxcoudert at gmail dot com>]

> I've submitted a patch to remove the use of PATH_MAX
> from gfortran.  Apparently, there is at least one
> target that does not define PATH_MAX.  Please, don't
> use PATH_MAX.

Here is the new patch, without PATH_MAX. OK to commit?

FX
2005-08-07  Francois-Xavier Coudert  <coudert@clipper.ens.fr>

	* acinclude.m4 (LIBGFOR_CHECK_UNLINK_OPEN_FILE): Add check to see
	if target can unlink open files.
	* configure.ac: Use this new test.
	* config.h.in: Regenerate.
	* configure: Regenerate.
	* io/io.h: Add prototype for unpack_filename.
	* io/close.c (st_close): Delete file after closing unit if
	HAVE_UNLINK_OPEN_FILE is not defined. 
	* io/unix.c (unpack_filename): Unlink scratch file after opening
	it only if HAVE_UNLINK_OPEN_FILE is defined.

Index: libgfortran/acinclude.m4
===================================================================
RCS file: /cvs/gcc/gcc/libgfortran/acinclude.m4,v
retrieving revision 1.5
diff -u -3 -p -r1.5 acinclude.m4
--- libgfortran/acinclude.m4	12 Dec 2004 08:59:01 -0000	1.5
+++ libgfortran/acinclude.m4	7 Aug 2005 17:58:03 -0000
@@ -148,3 +148,38 @@ extern void bar(void) __attribute__((ali
     AC_DEFINE(HAVE_ATTRIBUTE_ALIAS, 1,
       [Define to 1 if the target supports __attribute__((alias(...))).])
   fi])
+
+dnl Check whether target can unlink a file still open.
+AC_DEFUN([LIBGFOR_CHECK_UNLINK_OPEN_FILE], [
+  AC_CACHE_CHECK([whether the target can unlink an open file],
+                  have_unlink_open_file, [
+  AC_TRY_RUN([
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/stat.h>
+
+int main ()
+{
+  int fd;
+
+  fd = open ("testfile", O_RDWR | O_CREAT, S_IWRITE | S_IREAD);
+  if (fd <= 0)
+    return 0;
+  if (unlink ("testfile") == -1)
+    return 1;
+  write (fd, "This is a test\n", 15);
+  close (fd);
+
+  if (open ("testfile", O_RDONLY, S_IWRITE | S_IREAD) == -1 && errno == ENOENT)
+    return 0;
+  else
+    return 1;
+}], have_unlink_open_file=yes, have_unlink_open_file=no, [
+case "${target}" in
+  *mingw*) have_unlink_open_file=no ;;
+  *) have_unlink_open_file=yes;;
+esac])])
+if test x"$have_unlink_open_file" = xyes; then
+  AC_DEFINE(HAVE_UNLINK_OPEN_FILE, 1, [Define if target can unlink open files.])
+fi])
Index: libgfortran/configure.ac
===================================================================
RCS file: /cvs/gcc/gcc/libgfortran/configure.ac,v
retrieving revision 1.30
diff -u -3 -p -r1.30 configure.ac
--- libgfortran/configure.ac	24 Jun 2005 23:07:13 -0000	1.30
+++ libgfortran/configure.ac	7 Aug 2005 17:58:03 -0000
@@ -258,6 +258,9 @@ LIBGFOR_CHECK_ATTRIBUTE_VISIBILITY
 LIBGFOR_CHECK_ATTRIBUTE_DLLEXPORT
 LIBGFOR_CHECK_ATTRIBUTE_ALIAS
 
+# Various other checks on target
+LIBGFOR_CHECK_UNLINK_OPEN_FILE
+
 AC_CACHE_SAVE
 
 if test ${multilib} = yes; then
Index: libgfortran/io/close.c
===================================================================
RCS file: /cvs/gcc/gcc/libgfortran/io/close.c,v
retrieving revision 1.6
diff -u -3 -p -r1.6 close.c
--- libgfortran/io/close.c	15 May 2005 12:44:41 -0000	1.6
+++ libgfortran/io/close.c	7 Aug 2005 17:58:03 -0000
@@ -30,6 +30,7 @@ Boston, MA 02111-1307, USA.  */
 #include "config.h"
 #include "libgfortran.h"
 #include "io.h"
+#include <limits.h>
 
 typedef enum
 { CLOSE_DELETE, CLOSE_KEEP, CLOSE_UNSPECIFIED }
@@ -50,6 +51,9 @@ st_close (void)
 {
   close_status status;
   gfc_unit *u;
+#if !HAVE_UNLINK_OPEN_FILE
+  char * path;
+#endif
 
   library_start ();
 
@@ -68,14 +72,30 @@ st_close (void)
 	  if (status == CLOSE_KEEP)
 	    generate_error (ERROR_BAD_OPTION,
 			    "Can't KEEP a scratch file on CLOSE");
+#if !HAVE_UNLINK_OPEN_FILE
+	  path = (char *) alloca (u->file_len + 1);
+          unpack_filename (path, u->file, u->file_len);
+#endif
 	}
       else
 	{
 	  if (status == CLOSE_DELETE)
-	    delete_file (u);
+            {
+#if HAVE_UNLINK_OPEN_FILE
+	      delete_file (u);
+#else
+	      path = (char *) alloca (u->file_len + 1);
+              unpack_filename (path, u->file, u->file_len);
+#endif
+            }
 	}
 
       close_unit (u);
+
+#if !HAVE_UNLINK_OPEN_FILE
+      if (u->flags.status == STATUS_SCRATCH || status == CLOSE_DELETE)
+        unlink (path);
+#endif
     }
 
   library_end ();
Index: libgfortran/io/io.h
===================================================================
RCS file: /cvs/gcc/gcc/libgfortran/io/io.h,v
retrieving revision 1.23
diff -u -3 -p -r1.23 io.h
--- libgfortran/io/io.h	6 Aug 2005 22:57:46 -0000	1.23
+++ libgfortran/io/io.h	7 Aug 2005 17:58:03 -0000
@@ -499,6 +499,9 @@ internal_proto(flush);
 extern int unit_to_fd (int);
 internal_proto(unit_to_fd);
 
+extern int unpack_filename (char *, const char *, int);
+internal_proto(unpack_filename);
+
 /* unit.c */
 
 extern void insert_unit (gfc_unit *);
Index: libgfortran/io/unix.c
===================================================================
RCS file: /cvs/gcc/gcc/libgfortran/io/unix.c,v
retrieving revision 1.32
diff -u -3 -p -r1.32 unix.c
--- libgfortran/io/unix.c	6 Aug 2005 22:57:46 -0000	1.32
+++ libgfortran/io/unix.c	7 Aug 2005 17:58:04 -0000
@@ -952,7 +952,7 @@ unit_to_fd(int unit)
  * buffer that is PATH_MAX characters, convert the fortran string to a
  * C string in the buffer.  Returns nonzero if this is not possible.  */
 
-static int
+int
 unpack_filename (char *cstring, const char *fstring, int len)
 {
   len = fstrlen (fstring, len);
@@ -1136,8 +1136,11 @@ open_external (unit_flags *flags)
       fd = tempfile ();
       if (flags->action == ACTION_UNSPECIFIED)
         flags->action = ACTION_READWRITE;
+
+#if HAVE_UNLINK_OPEN_FILE
       /* We can unlink scratch files now and it will go away when closed. */
       unlink (ioparm.file);
+#endif
     }
   else
     {