libgo/runtime/go-make-slice.c

   1 /* go-make-slice.c -- make a slice.
   2
   3    Copyright 2011 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 <stdint.h>
   8
   9 #include "go-alloc.h"
  10 #include "go-assert.h"
  11 #include "go-panic.h"
  12 #include "go-type.h"
  13 #include "array.h"
  14 #include "runtime.h"
  15 #include "arch.h"
  16 #include "malloc.h"
  17
  18 struct __go_open_array
  19 __go_make_slice2 (const struct __go_type_descriptor *td, uintptr_t len,
  20                   uintptr_t cap)
  21 {
  22   const struct __go_slice_type* std;
  23   int ilen;
  24   int icap;
  25   uintptr_t size;
  26   struct __go_open_array ret;
  27   unsigned int flag;
  28
  29   __go_assert (td->__code == GO_SLICE);
  30   std = (const struct __go_slice_type *) td;
  31
  32   ilen = (int) len;
  33   if (ilen < 0 || (uintptr_t) ilen != len)
  34     runtime_panicstring ("makeslice: len out of range");
  35
  36   icap = (int) cap;
  37   if (cap < len
  38       || (uintptr_t) icap != cap
  39       || (std->__element_type->__size > 0
  40           && cap > (uintptr_t) -1U / std->__element_type->__size))
  41     runtime_panicstring ("makeslice: cap out of range");
  42
  43   ret.__count = ilen;
  44   ret.__capacity = icap;
  45
  46   size = cap * std->__element_type->__size;
  47   flag = ((std->__element_type->__code & GO_NO_POINTERS) != 0
  48           ? FlagNoPointers
  49           : 0);
  50   ret.__values = runtime_mallocgc (size, flag, 1, 1);
  51
  52   return ret;
  53 }
  54
  55 struct __go_open_array
  56 __go_make_slice1 (const struct __go_type_descriptor *td, uintptr_t len)
  57 {
  58   return __go_make_slice2 (td, len, len);
  59 }