github.com/rakyll/go@v0.0.0-20170216000551-64c02460d703/src/cmd/compile/internal/gc/sizeof_test.go (about)

     1  // Copyright 2016 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  // +build !nacl
     6  
     7  package gc
     8  
     9  import (
    10  	"reflect"
    11  	"testing"
    12  	"unsafe"
    13  )
    14  
    15  // Assert that the size of important structures do not change unexpectedly.
    16  
    17  func TestSizeof(t *testing.T) {
    18  	const _64bit = unsafe.Sizeof(uintptr(0)) == 8
    19  
    20  	var tests = []struct {
    21  		val    interface{} // type as a value
    22  		_32bit uintptr     // size on 32bit platforms
    23  		_64bit uintptr     // size on 64bit platforms
    24  	}{
    25  		{Func{}, 100, 168},
    26  		{Name{}, 40, 64},
    27  		{Param{}, 28, 56},
    28  		{Node{}, 96, 152},
    29  		{Sym{}, 64, 120},
    30  		{Type{}, 64, 104},
    31  		{MapType{}, 20, 40},
    32  		{ForwardType{}, 20, 32},
    33  		{FuncType{}, 28, 48},
    34  		{StructType{}, 12, 24},
    35  		{InterType{}, 4, 8},
    36  		{ChanType{}, 8, 16},
    37  		{ArrayType{}, 16, 24},
    38  		{InterMethType{}, 4, 8},
    39  		{DDDFieldType{}, 4, 8},
    40  		{FuncArgsType{}, 4, 8},
    41  		{ChanArgsType{}, 4, 8},
    42  		{PtrType{}, 4, 8},
    43  		{SliceType{}, 4, 8},
    44  	}
    45  
    46  	for _, tt := range tests {
    47  		want := tt._32bit
    48  		if _64bit {
    49  			want = tt._64bit
    50  		}
    51  		got := reflect.TypeOf(tt.val).Size()
    52  		if want != got {
    53  			t.Errorf("unsafe.Sizeof(%T) = %d, want %d", tt.val, got, want)
    54  		}
    55  	}
    56  }