symbol 'sin'. cmd/link also processes the cgo_ldflag directives, so that it
knows that the eventual host link command must include the -lm
argument, so that the host linker will be able to find 'sin' in the
math library.

cmd/link Command Line Interface

The go command and any other Go-aware build systems invoke cmd/link
to link a collection of packages into a single binary. By default, cmd/link will

	}
	c, err := b.ReadByte()
	if err != nil {
		t.Fatalf("ReadByte: %v", err)
	}
	if c != 'm' {
		t.Errorf("ReadByte = %q; want %q", c, 'm')
	}
}

// Tests that we occasionally compact. Issue 5154.
func TestBufferGrowth(t *testing.T) {
	var b Buffer
	buf := make([]byte, 1024)
	b.Write(buf[0:1])
	var cap0 int
	for i := 0; i < 5<<10; i++ {
		b.Write(buf)
		b.Read(buf)
		if i == 0 {

support for concurrent programming.  Programs are constructed from
<i>packages</i>, whose properties allow efficient management of
dependencies.
</p>

<p>
The grammar is compact and simple to parse, allowing for easy analysis
by automatic tools such as integrated development environments.
</p>

<h2 id="Notation">Notation</h2>
<p>
The syntax is specified using Extended Backus-Naur Form (EBNF):

Vendoring in std and cmd
========================

The Go command maintains copies of external packages needed by the
standard library in the src/vendor and src/cmd/vendor directories.

There are two modules, std and cmd, defined in src/go.mod and
src/cmd/go.mod. When a package outside std or cmd is imported
by a package inside std or cmd, the import path is interpreted
as if it had a "vendor/" prefix. For example, within "crypto/tls",

package main

import (
	"bufio"
	"bytes"
	"internal/testenv"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"sync"
	"testing"
)

// TestMain executes the test binary as the addr2line command if
// GO_ADDR2LINETEST_IS_ADDR2LINE is set, and runs the tests otherwise.
func TestMain(m *testing.M) {
	if os.Getenv("GO_ADDR2LINETEST_IS_ADDR2LINE") != "" {
		main()
		os.Exit(0)
	}

}

func ExampleCompare() {
	// Interpret Compare's result by comparing it to zero.
	var a, b []byte
	if bytes.Compare(a, b) < 0 {
		// a less b
	}
	if bytes.Compare(a, b) <= 0 {
		// a less or equal b
	}
	if bytes.Compare(a, b) > 0 {
		// a greater b
	}
	if bytes.Compare(a, b) >= 0 {
		// a greater or equal b
	}

	// Prefer Equal to Compare for equality comparisons.
	if bytes.Equal(a, b) {

are also treated as invalid.
(Older toolchains ignore `//go:debug` directives entirely.)

The defaults that will be compiled into a main package
are reported by the command:

{{raw `
	go list -f '{{.DefaultGODEBUG}}' my/main/package
`}}

Only differences from the base Go toolchain defaults are reported.

When testing a package, `//go:debug` lines in the `*_test.go`

	return string(a) == string(b)
}

// Compare returns an integer comparing two byte slices lexicographically.
// The result will be 0 if a == b, -1 if a < b, and +1 if a > b.
// A nil argument is equivalent to an empty slice.
func Compare(a, b []byte) int {
	return bytealg.Compare(a, b)
}

support for concurrent programming.  Programs are constructed from
<i>packages</i>, whose properties allow efficient management of
dependencies.
</p>

<p>
The syntax is compact and simple to parse, allowing for easy analysis
by automatic tools such as integrated development environments.
</p>

<h2 id="Notation">Notation</h2>
<p>
The syntax is specified using a

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

// This package computes the exported API of a set of Go packages.
// It is only a test, not a command, nor a usefully importable package.

package main

import (
	"bufio"
	"bytes"
	"encoding/json"
	"fmt"
	"go/ast"
	"go/build"
	"go/parser"
	"go/token"
	"go/types"
	"internal/testenv"
	"io"