re PR java/2319 (invalid UTF-8 sequences should be rejected)

	* lex.c (java_read_char): Disallow invalid and overlong
	sequences.  Fixes PR java/2319.

From-SVN: r43475

diff --git a/gcc/java/ChangeLog b/gcc/java/ChangeLog
index f55ad6c..96e1ba5 100644 (file)
--- a/gcc/java/ChangeLog
+++ b/gcc/java/ChangeLog
@@ -1,3 +1,8 @@
+2001-06-19  Tom Tromey  <tromey@redhat.com>
+
+       * lex.c (java_read_char): Disallow invalid and overlong
+       sequences.  Fixes PR java/2319.
+
 2001-06-05  Jeff Sturm  <jsturm@one-point.com>
 
        * decl.c (create_primitive_vtable): Don't call make_decl_rtl.

diff --git a/gcc/java/lex.c b/gcc/java/lex.c
index 28a73e3..35cd317 100644 (file)
--- a/gcc/java/lex.c
+++ b/gcc/java/lex.c
@@ -454,15 +454,21 @@ java_read_char (lex)
       if (c == EOF)
        return UEOF;
       if (c < 128)
-       return (unicode_t)c;
+       return (unicode_t) c;
       else
        {
          if ((c & 0xe0) == 0xc0)
            {
              c1 = getc (lex->finput);
              if ((c1 & 0xc0) == 0x80)
-               return (unicode_t)(((c &0x1f) << 6) + (c1 & 0x3f));
-             c = c1;
+               {
+                 unicode_t r = (unicode_t)(((c & 0x1f) << 6) + (c1 & 0x3f));
+                 /* Check for valid 2-byte characters.  We explicitly
+                    allow \0 because this encoding is common in the
+                    Java world.  */
+                 if (r == 0 || (r >= 0x80 && r <= 0x7ff))
+                   return r;
+               }
            }
          else if ((c & 0xf0) == 0xe0)
            {
@@ -471,16 +477,23 @@ java_read_char (lex)
                {
                  c2 = getc (lex->finput);
                  if ((c2 & 0xc0) == 0x80)
-                   return (unicode_t)(((c & 0xf) << 12) + 
-                                      (( c1 & 0x3f) << 6) + (c2 & 0x3f));
-                 else
-                   c = c2;
+                   {
+                     unicode_t r =  (unicode_t)(((c & 0xf) << 12) + 
+                                                (( c1 & 0x3f) << 6)
+                                                + (c2 & 0x3f));
+                     /* Check for valid 3-byte characters.
+                        Don't allow surrogate, \ufffe or \uffff.  */
+                     if (r >= 0x800 && r <= 0xffff
+                         && ! (r >= 0xd800 && r <= 0xdfff)
+                         && r != 0xfffe && r != 0xffff)
+                       return r;
+                   }
                }
-             else
-               c = c1;
            }
 
-         /* We simply don't support invalid characters.  */
+         /* We simply don't support invalid characters.  We also
+            don't support 4-, 5-, or 6-byte UTF-8 sequences, as these
+            cannot be valid Java characters.  */
          java_lex_error ("malformed UTF-8 character", 0);
        }
     }