"golang.org/x/tools/internal/typeparams"
)

//go:embed doc.go
var doc string

var Analyzer = &analysis.Analyzer{
	Name:     "nilfunc",
	Doc:      analysisutil.MustExtractDoc(doc, "nilfunc"),
	URL:      "https://pkg.go.dev/golang.org/x/tools/go/analysis/passes/nilfunc",
	Requires: []*analysis.Analyzer{inspect.Analyzer},
	Run:      run,
}

func run(pass *analysis.Pass) (interface{}, error) {

// Copyright 2013 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.

package nilfunc

func F() {}

func Comparison() {
	if F == nil { // ERROR "comparison of function F == nil is always false"
		panic("can't happen")
	}

// license that can be found in the LICENSE file.

// Package nilfunc defines an Analyzer that checks for useless
// comparisons against nil.
//
// # Analyzer nilfunc
//
// nilfunc: check for useless comparisons between functions and nil
//
// A useless comparison is one like f == nil as opposed to f() == nil.

	"golang.org/x/tools/go/analysis/passes/ifaceassert"
	"golang.org/x/tools/go/analysis/passes/loopclosure"
	"golang.org/x/tools/go/analysis/passes/lostcancel"
	"golang.org/x/tools/go/analysis/passes/nilfunc"
	"golang.org/x/tools/go/analysis/passes/printf"
	"golang.org/x/tools/go/analysis/passes/shift"
	"golang.org/x/tools/go/analysis/passes/sigchanyzer"
	"golang.org/x/tools/go/analysis/passes/slog"

	"errorsas":         true,
	"framepointer":     true,
	"httpresponse":     true,
	"ifaceassert":      true,
	"loopclosure":      true,
	"lostcancel":       true,
	"methods":          true,
	"nilfunc":          true,
	"printf":           true,
	"rangeloops":       true,
	"shift":            true,
	"sigchanyzer":      true,
	"slog":             true,
	"stdmethods":       true,
	"stdversion":       true,

	bytes                     = []byte("hello, world")
	four, five                = 4, 5
	x, y                      = 0.1, "hello"
	nilslice   []byte         = nil
	nilmap     map[string]int = nil
	nilfunc    func()         = nil
	nilchan    chan int       = nil
	nilptr     *byte          = nil
)

var a = [3]int{1001, 1002, 1003}
var s = S{1101, 1102, 1103}
var c = []int{1201, 1202, 1203}

# Test with a single analyzer
! go test -vet=httpresponse ./vetall/...
stderr 'using resp before checking for errors'

# Test with a list of analyzers
go test -vet=atomic,bools,nilfunc ./vetall/...
stdout 'm/vetall.*\[no tests to run\]'

# Test issue #22890
go test m/vetcycle
stdout 'm/vetcycle.*\[no test files\]'

# Test with ...
! go test ./vetfail/...
stderr 'Printf format %d'

    --- PASS: TestVet/5 (0.07s)
        vet_test.go:114: files: ["testdata/copylock_func.go" "testdata/rangeloop.go"]
    --- PASS: TestVet/3 (0.07s)
        vet_test.go:114: files: ["testdata/composite.go" "testdata/nilfunc.go"]
    --- PASS: TestVet/6 (0.07s)
        vet_test.go:114: files: ["testdata/copylock_range.go" "testdata/shadow.go"]
    --- PASS: TestVet/2 (0.07s)

    --- PASS: Test☺☹/5 (0.07s)
        vet_test.go:114: φιλεσ: ["testdata/copylock_func.go" "testdata/rangeloop.go"]
    --- PASS: Test☺☹/3 (0.07s)
        vet_test.go:114: φιλεσ: ["testdata/composite.go" "testdata/nilfunc.go"]
    --- PASS: Test☺☹/6 (0.07s)
        vet_test.go:114: φιλεσ: ["testdata/copylock_range.go" "testdata/shadow.go"]
    --- PASS: Test☺☹/2 (0.07s)

	loopclosure      check references to loop variables from within nested functions
	lostcancel       check cancel func returned by context.WithCancel is called
	nilfunc          check for useless comparisons between functions and nil
	printf           check consistency of Printf format strings and arguments
	shift            check for shifts that equal or exceed the width of the integer