[patch,fortran] PR69043 Trying to include a directory causes an infinite loop

[Jerry DeLisle]

I plan to commit the attached patch and test case under simple and obvious 
tomorrow.

Regression tested on x86-64-linux.

Regards,

Jerry

2016-03-13  Jerry DeLisle  <jvdeli...@gcc.gnu.org>
            Jim MacArthur  <jim.macart...@codethink.co.uk>

        PR fortran/69043
        * scanner.c (load_file): Check that included file is not a directory.

diff --git a/gcc/fortran/scanner.c b/gcc/fortran/scanner.c
index c4e7974..d4c14bc 100644
--- a/gcc/fortran/scanner.c
+++ b/gcc/fortran/scanner.c
@@ -2200,6 +2200,8 @@ load_file (const char *realfilename, const char *displayedname, bool initial)
   FILE *input;
   int len, line_len;
   bool first_line;
+  struct stat st;
+  int stat_result;
   const char *filename;
   /* If realfilename and displayedname are different and non-null then
      surely realfilename is the preprocessed form of
@@ -2227,6 +2229,7 @@ load_file (const char *realfilename, const char *displayedname, bool initial)
 	}
       else
 	input = gfc_open_file (realfilename);
+
       if (input == NULL)
 	{
 	  gfc_error_now ("Can't open file %qs", filename);
@@ -2242,6 +2245,16 @@ load_file (const char *realfilename, const char *displayedname, bool initial)
 		   current_file->filename, current_file->line, filename);
 	  return false;
 	}
+
+      stat_result = stat (realfilename, &st);
+      if (stat_result == 0 && st.st_mode & S_IFDIR)
+	{
+	  fprintf (stderr, "%s:%d: Error: Included path '%s'"
+		   " is a directory.\n",
+		   current_file->filename, current_file->line, filename);
+	  fclose (input);
+	  return false;
+	}
     }
 
   /* Load the file.

! { dg-do compile }
! PR69043 Trying to include a directory causes an infinite loop
      include '.'
      program main
      end program

! { dg-error "is a directory" " " { target *-*-* } 3 }