* lread.c: Integer overflow fixes.

(read_integer): Radix is now EMACS_INT, not int,
to improve quality of diagnostics for out-of-range radices.
Calculate buffer size correctly for out-of-range radices.
(read1): Check for integer overflow in radices, and in
read-circle numbers.

diff --git a/src/ChangeLog b/src/ChangeLog
index 7f174bf0a21820e1e72d51059aed0fa455e5c5f5..96e6741f11f60a6acf30a07678325dbae1dc5c9f 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,12 @@
 2011-06-23  Paul Eggert  <eggert@cs.ucla.edu>
 
+       * lread.c: Integer overflow fixes.
+       (read_integer): Radix is now EMACS_INT, not int,
+       to improve quality of diagnostics for out-of-range radices.
+       Calculate buffer size correctly for out-of-range radices.
+       (read1): Check for integer overflow in radices, and in
+       read-circle numbers.
+
        * image.c (cache_image): Check for size arithmetic overflow.
 
 2011-06-22  Paul Eggert  <eggert@cs.ucla.edu>

diff --git a/src/lread.c b/src/lread.c
index a2f78f848ae2ec37af29d682cc2e372aab0e827b..2f1c05c5aa198cd17d796c0e0d2cb7d68466dd14 100644 (file)
--- a/src/lread.c
+++ b/src/lread.c
@@ -2277,10 +2277,12 @@ digit_to_number (int character, int base)
    range.  */
 
 static Lisp_Object
-read_integer (Lisp_Object readcharfun, int radix)
+read_integer (Lisp_Object readcharfun, EMACS_INT radix)
 {
-  /* Room for sign, leading 0, other digits, trailing null byte.  */
-  char buf[1 + 1 + sizeof (uintmax_t) * CHAR_BIT + 1];
+  /* Room for sign, leading 0, other digits, trailing null byte.
+     Also, room for invalid syntax diagnostic.  */
+  char buf[max (1 + 1 + sizeof (uintmax_t) * CHAR_BIT + 1,
+               sizeof "integer, radix " + INT_STRLEN_BOUND (EMACS_INT))];
 
   int valid = -1; /* 1 if valid, 0 if not, -1 if incomplete.  */
 
@@ -2332,7 +2334,7 @@ read_integer (Lisp_Object readcharfun, int radix)
 
   if (! valid)
     {
-      sprintf (buf, "integer, radix %d", radix);
+      sprintf (buf, "integer, radix %"pI"d", radix);
       invalid_syntax (buf);
     }
 
@@ -2663,49 +2665,60 @@ read1 (register Lisp_Object readcharfun, int *pch, int first_in_list)
       /* Reader forms that can reuse previously read objects.  */
       if (c >= '0' && c <= '9')
        {
-         int n = 0;
+         EMACS_INT n = 0;
          Lisp_Object tem;
 
          /* Read a non-negative integer.  */
          while (c >= '0' && c <= '9')
            {
-             n *= 10;
-             n += c - '0';
+             if (MOST_POSITIVE_FIXNUM / 10 < n
+                 || MOST_POSITIVE_FIXNUM < n * 10 + c - '0')
+               n = MOST_POSITIVE_FIXNUM + 1;
+             else
+               n = n * 10 + c - '0';
              c = READCHAR;
            }
-         /* #n=object returns object, but associates it with n for #n#.  */
-         if (c == '=' && !NILP (Vread_circle))
+
+         if (n <= MOST_POSITIVE_FIXNUM)
            {
-             /* Make a placeholder for #n# to use temporarily */
-             Lisp_Object placeholder;
-             Lisp_Object cell;
+             if (c == 'r' || c == 'R')
+               return read_integer (readcharfun, n);
 
-             placeholder = Fcons (Qnil, Qnil);
-             cell = Fcons (make_number (n), placeholder);
-             read_objects = Fcons (cell, read_objects);
+             if (! NILP (Vread_circle))
+               {
+                 /* #n=object returns object, but associates it with
+                      n for #n#.  */
+                 if (c == '=')
+                   {
+                     /* Make a placeholder for #n# to use temporarily */
+                     Lisp_Object placeholder;
+                     Lisp_Object cell;
 
-             /* Read the object itself. */
-             tem = read0 (readcharfun);
+                     placeholder = Fcons (Qnil, Qnil);
+                     cell = Fcons (make_number (n), placeholder);
+                     read_objects = Fcons (cell, read_objects);
 
-             /* Now put it everywhere the placeholder was... */
-             substitute_object_in_subtree (tem, placeholder);
+                     /* Read the object itself. */
+                     tem = read0 (readcharfun);
 
-             /* ...and #n# will use the real value from now on.  */
-             Fsetcdr (cell, tem);
+                     /* Now put it everywhere the placeholder was... */
+                     substitute_object_in_subtree (tem, placeholder);
 
-             return tem;
-           }
-         /* #n# returns a previously read object.  */
-         if (c == '#' && !NILP (Vread_circle))
-           {
-             tem = Fassq (make_number (n), read_objects);
-             if (CONSP (tem))
-               return XCDR (tem);
-             /* Fall through to error message.  */
-           }
-         else if (c == 'r' ||  c == 'R')
-           return read_integer (readcharfun, n);
+                     /* ...and #n# will use the real value from now on.  */
+                     Fsetcdr (cell, tem);
 
+                     return tem;
+                   }
+
+                 /* #n# returns a previously read object.  */
+                 if (c == '#')
+                   {
+                     tem = Fassq (make_number (n), read_objects);
+                     if (CONSP (tem))
+                       return XCDR (tem);
+                   }
+               }
+           }
          /* Fall through to error message.  */
        }
       else if (c == 'x' || c == 'X')