src/go/types/sizeof_test.go

   1 // Copyright 2021 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 package types
   6
   7 import (
   8         "reflect"
   9         "testing"
  10 )
  11
  12 // Signal size changes of important structures.
  13 func TestSizeof(t *testing.T) {
  14         const _64bit = ^uint(0)>>32 != 0
  15
  16         var tests = []struct {
  17                 val    any     // type as a value
  18                 _32bit uintptr // size on 32bit platforms
  19                 _64bit uintptr // size on 64bit platforms
  20         }{
  21                 // Types
  22                 {Basic{}, 16, 32},
  23                 {Array{}, 16, 24},
  24                 {Slice{}, 8, 16},
  25                 {Struct{}, 24, 48},
  26                 {Pointer{}, 8, 16},
  27                 {Tuple{}, 12, 24},
  28                 {Signature{}, 28, 56},
  29                 {Union{}, 12, 24},
  30                 {Interface{}, 40, 80},
  31                 {Map{}, 16, 32},
  32                 {Chan{}, 12, 24},
  33                 {Named{}, 60, 112},
  34                 {TypeParam{}, 28, 48},
  35                 {term{}, 12, 24},
  36
  37                 // Objects
  38                 {PkgName{}, 48, 88},
  39                 {Const{}, 48, 88},
  40                 {TypeName{}, 40, 72},
  41                 {Var{}, 48, 88},
  42                 {Func{}, 48, 88},
  43                 {Label{}, 44, 80},
  44                 {Builtin{}, 44, 80},
  45                 {Nil{}, 40, 72},
  46
  47                 // Misc
  48                 {Scope{}, 44, 88},
  49                 {Package{}, 44, 88},
  50                 {_TypeSet{}, 28, 56},
  51         }
  52         for _, test := range tests {
  53                 got := reflect.TypeOf(test.val).Size()
  54                 want := test._32bit
  55                 if _64bit {
  56                         want = test._64bit
  57                 }
  58                 if got != want {
  59                         t.Errorf("unsafe.Sizeof(%T) = %d, want %d", test.val, got, want)
  60                 }
  61         }
  62 }