use of int and overflow review

[chiark-tcl.git] / hbytes / chop.c

diff --git a/hbytes/chop.c b/hbytes/chop.c
index 48eb770310fc5dbc813b445a7fa41ae3f9883f42..e649b5aa12a4dce45eb4ade79de62d2347d21c06 100644 (file)
--- a/hbytes/chop.c
+++ b/hbytes/chop.c
@@ -1,19 +1,36 @@
 /*
+ * hbytes - hex-stringrep efficient byteblocks for Tcl
+ * Copyright 2006 Ian Jackson
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
  */
 
-#include <string.h>
 
-#include "hbytes.h"
-#include "tables.h"
+#include "chiark_tcl_hbytes.h"
 
 static int strs1(Tcl_Interp *ip, int strc, Tcl_Obj *const *strv, int *l_r) {
-  int rc, l, i;
+  int rc, l, i, pl;
 
   l= 0;
   for (i=1; i<strc; i++) {
-    rc= Tcl_ConvertToType(ip,strv[i],&hbytes_type);
+    rc= Tcl_ConvertToType(ip,strv[i],&cht_hbytes_type);
     if (rc) return rc;
-    l += hbytes_len(OBJ_HBYTES(strv[i]));
+    pl= cht_hb_len(OBJ_HBYTES(strv[i]));
+    assert(l < INT_MAX/2 && pl < INT_MAX/2);
+    l += pl;
   }
   *l_r= l;
   return TCL_OK;
@@ -23,65 +40,67 @@ static void strs2(Byte *dest, int strc, Tcl_Obj *const *strv) {
   int tl, i;
   
   for (i=1; i<strc; i++) {
-    tl= hbytes_len(OBJ_HBYTES(strv[i]));
-    memcpy(dest, hbytes_data(OBJ_HBYTES(strv[i])), tl);
+    tl= cht_hb_len(OBJ_HBYTES(strv[i]));
+    memcpy(dest, cht_hb_data(OBJ_HBYTES(strv[i])), tl);
     dest += tl;
   }
 }
 
-int do_hbytes_prepend(ClientData cd, Tcl_Interp *ip,
+int cht_do_hbytes_prepend(ClientData cd, Tcl_Interp *ip,
                      HBytes_Var v, int strc, Tcl_Obj *const *strv) {
   int rc, el;
   Byte *dest;
   
   rc= strs1(ip,strc,strv,&el);  if (rc) return rc;
-  dest= hbytes_prepend(v.hb, el);
+  dest= cht_hb_prepend(v.hb, el);
   strs2(dest, strc,strv);
   return TCL_OK;
 }
   
-int do_hbytes_append(ClientData cd, Tcl_Interp *ip,
+int cht_do_hbytes_append(ClientData cd, Tcl_Interp *ip,
                     HBytes_Var v, int strc, Tcl_Obj *const *strv) {
   int rc, el;
   Byte *dest;
 
   rc= strs1(ip,strc,strv,&el);  if (rc) return rc;
-  dest= hbytes_append(v.hb, el);
+  dest= cht_hb_append(v.hb, el);
   strs2(dest,  strc,strv);
   return TCL_OK;
 }
 
-int do_hbytes_concat(ClientData cd, Tcl_Interp *ip,
+int cht_do_hbytes_concat(ClientData cd, Tcl_Interp *ip,
                     int strc, Tcl_Obj *const *strv, HBytes_Value *result) {
   int rc, l;
   Byte *dest;
   
   rc= strs1(ip,strc,strv,&l);  if (rc) return rc;
-  dest= hbytes_arrayspace(result,l);
+  dest= cht_hb_arrayspace(result,l);
   strs2(dest, strc,strv);
   return TCL_OK;
 }
 
-static int underrun(Tcl_Interp *ip) { return staticerr(ip,"data underrun"); }
+static int underrun(Tcl_Interp *ip) {
+  return cht_staticerr(ip,"data underrun","HBYTES LENGTH UNDERRUN");
+}
 
-int do_hbytes_unprepend(ClientData cd, Tcl_Interp *ip,
+int cht_do_hbytes_unprepend(ClientData cd, Tcl_Interp *ip,
                        HBytes_Var v, int preflength, HBytes_Value *result) {
-  const Byte *rdata= hbytes_unprepend(v.hb, preflength);
+  const Byte *rdata= cht_hb_unprepend(v.hb, preflength);
   if (!rdata) return underrun(ip);
-  hbytes_array(result, rdata, preflength);
+  cht_hb_array(result, rdata, preflength);
   return TCL_OK;
 }
 
-int do_hbytes_unappend(ClientData cd, Tcl_Interp *ip,
+int cht_do_hbytes_unappend(ClientData cd, Tcl_Interp *ip,
                       HBytes_Var v, int suflength, HBytes_Value *result) {
-  const Byte *rdata= hbytes_unappend(v.hb, suflength);
+  const Byte *rdata= cht_hb_unappend(v.hb, suflength);
   if (!rdata) return underrun(ip);
-  hbytes_array(result, rdata, suflength);
+  cht_hb_array(result, rdata, suflength);
   return TCL_OK;
 }
 
-int do_hbytes_chopto(ClientData cd, Tcl_Interp *ip,
+int cht_do_hbytes_chopto(ClientData cd, Tcl_Interp *ip,
                     HBytes_Var v, int newlength, HBytes_Value *result) {
-  int suflength= hbytes_len(v.hb) - newlength;
-  return do_hbytes_unappend(0,ip,v, suflength, result);
+  int suflength= cht_hb_len(v.hb) - newlength;
+  return cht_do_hbytes_unappend(0,ip,v, suflength, result);
 }