## Tools {#tools}

### Go command {#go-command}

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build cgo

package reflect_test

import (
	. "reflect"
	"runtime/cgo"
	"testing"
	"unsafe"
)

type nih struct {
	_ cgo.Incomplete
	x int
}

var global_nih = nih{x: 7}

func TestNotInHeapDeref(t *testing.T) {
	// See issue 48399.
	v := ValueOf((*nih)(nil))

! go list
stderr '^go: updates to go.mod needed; to update it:\n\tgo mod tidy'

# However, it should not reject files missing a 'go' directive,
# since that was not always required.
cp go.mod.nogo go.mod
go list all
cmp go.mod go.mod.nogo

# Nor should it reject files with redundant (not incorrect)
# requirements.
cp go.mod.redundant go.mod
go list all
cmp go.mod go.mod.redundant

cp go.mod.indirect go.mod
go list all

# Issue #66456

[!cgo] skip
[GOOS:windows] skip
[GOOS:plan9] skip

# Generate a file with a very long #cgo LDFLAGS line.
# This used to cause "go build" to fail with "argument list too long".
go generate

# Build with the generated file.
go build

-- go.mod --
module cgolongcmd

go 1.22
-- generate.go --
//go:build ignore

package main

import (
	"fmt"
	"log"
	"os"
	"bytes"
)

# Tests golang.org/issue/36000

[!cgo] skip

# go env with CGO flags should not make NUL file

		"pkg/**",

		// Generated during cmd/dist. See ../dist/build.go:/gentab.
		"src/cmd/go/internal/cfg/zdefaultcc.go",
		"src/go/build/zcgo.go",
		"src/runtime/internal/sys/zversion.go",
		"src/time/tzdata/zzipdata.go",

		// Generated during cmd/dist by bootstrapBuildTools.
		"src/cmd/cgo/zdefaultcc.go",
		"src/cmd/internal/objabi/zbootstrap.go",
		"src/internal/buildcfg/zbootstrap.go",

{"Action":"pause","Test":"TestVetDirs/incomplete"}
{"Action":"run","Test":"TestVetDirs/cgo"}
{"Action":"output","Test":"TestVetDirs/cgo","Output":"=== RUN   TestVetDirs/cgo\n"}
{"Action":"output","Test":"TestVetDirs/cgo","Output":"=== PAUSE TestVetDirs/cgo\n"}
{"Action":"pause","Test":"TestVetDirs/cgo"}
{"Action":"cont","Test":"TestVet/7"}
{"Action":"output","Test":"TestVet/7","Output":"=== CONT  TestVet/7\n"}

// Copyright 2020 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build cgo

package main

import (
	"runtime/cgo"
	"unsafe"
)

type S struct {
	_ cgo.Incomplete
	x int
}

func main() {
	var i int
	p := (*S)(unsafe.Pointer(uintptr(unsafe.Pointer(&i))))
	v := uintptr(unsafe.Pointer(p))

env GOCACHE=$WORK${/}.cache
mkdir $GOCACHE

go build -x runtime/cgo

	# Tell our fake clang to stop working.
	# Previously, 'go build -x runtime/cgo' would continue to
	# succeed because both the broken clang and the non-broken one
	# resulted in a cache key with no clang version information.
env GO_BREAK_CLANG=1
! go build -x runtime/cgo
stderr '# runtime/cgo\nGO_BREAK_CLANG is set'

-- go.mod --
module example/issue64423

// Code generated by cmd/cgo -godefs; DO NOT EDIT.
// cgo -godefs defs_netbsd.go

package route

const (
	sizeofIfMsghdrNetBSD7         = 0x98
	sizeofIfaMsghdrNetBSD7        = 0x18
	sizeofIfAnnouncemsghdrNetBSD7 = 0x18

	sizeofRtMsghdrNetBSD7  = 0x78
	sizeofRtMetricsNetBSD7 = 0x50

	sizeofSockaddrStorage = 0x80
	sizeofSockaddrInet    = 0x10
	sizeofSockaddrInet6   = 0x1c