libgo/runtime/go-strplus.c

   1 /* go-strplus.c -- the go string append function.
   2
   3    Copyright 2009 The Go Authors. All rights reserved.
   4    Use of this source code is governed by a BSD-style
   5    license that can be found in the LICENSE file.  */
   6
   7 #include "go-string.h"
   8 #include "runtime.h"
   9 #include "malloc.h"
  10
  11 struct __go_string
  12 __go_string_plus (struct __go_string s1, struct __go_string s2)
  13 {
  14   int len;
  15   unsigned char *retdata;
  16   struct __go_string ret;
  17
  18   if (s1.__length == 0)
  19     return s2;
  20   else if (s2.__length == 0)
  21     return s1;
  22
  23   len = s1.__length + s2.__length;
  24   retdata = runtime_mallocgc (len, FlagNoPointers, 1, 0);
  25   __builtin_memcpy (retdata, s1.__data, s1.__length);
  26   __builtin_memcpy (retdata + s1.__length, s2.__data, s2.__length);
  27   ret.__data = retdata;
  28   ret.__length = len;
  29   return ret;
  30 }