// Copyright 2016 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 lostcancel

import "context"

func _() {
	var _, cancel = context.WithCancel(context.Background()) // ERROR "the cancel function is not used on all paths \(possible context leak\)"
	if false {
		_ = cancel
	}

	"golang.org/x/tools/go/cfg"
)

//go:embed doc.go
var doc string

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

const debug = false

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

// Package lostcancel defines an Analyzer that checks for failure to
// call a context cancellation function.
//
// # Analyzer lostcancel
//
// lostcancel: check cancel func returned by context.WithCancel is called
//
// The cancellation function returned by context.WithCancel, WithTimeout,

	"golang.org/x/tools/go/analysis/passes/httpresponse"
	"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"

	"defers":           true,
	"directive":        true,
	"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,

    --- PASS: TestVet/4 (0.16s)
        vet_test.go:114: files: ["testdata/copylock.go" "testdata/print.go"]
    --- PASS: TestVet/1 (0.07s)
        vet_test.go:114: files: ["testdata/atomic.go" "testdata/lostcancel.go" "testdata/unsafeptr.go"]
    --- PASS: TestVet/7 (0.19s)
        vet_test.go:114: files: ["testdata/deadcode.go" "testdata/shift.go"]
--- PASS: TestVetDirs (0.01s)
    --- PASS: TestVetDirs/testingpkg (0.06s)

    --- PASS: Test☺☹/4 (0.16s)
        vet_test.go:114: φιλεσ: ["testdata/copylock.go" "testdata/print.go"]
    --- PASS: Test☺☹/1 (0.07s)
        vet_test.go:114: φιλεσ: ["testdata/atomic.go" "testdata/lostcancel.go" "testdata/unsafeptr.go"]
    --- PASS: Test☺☹/7 (0.19s)
        vet_test.go:114: φιλεσ: ["testdata/deadcode.go" "testdata/shift.go"]
--- PASS: Test☺☹Dirs (0.01s)
    --- PASS: Test☺☹Dirs/testingpkg (0.06s)

	httpresponse     check for mistakes using HTTP responses
	ifaceassert      detect impossible interface-to-interface type assertions
	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

	//      ...
	//    }
	//
	//    ignoringTheErrorWouldBeVeryBad() // oops
	//

	// List standard library functions here.
	// The context.With{Cancel,Deadline,Timeout} entries are
	// effectively redundant wrt the lostcancel analyzer.
	funcs = stringSetFlag{
		"context.WithCancel":   true,
		"context.WithDeadline": true,
		"context.WithTimeout":  true,
		"context.WithValue":    true,
		"errors.New":           true,

golang.org/x/tools/go/analysis/passes/ifaceassert
golang.org/x/tools/go/analysis/passes/inspect
golang.org/x/tools/go/analysis/passes/internal/analysisutil
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