libgo/go/go/types/testdata/check/errors.src

// 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 errors

// Testing precise operand formatting in error messages
// (matching messages are regular expressions, hence the \'s).
func f(x int, m map[string]int) {
	// no values
	_ = f /* ERROR f\(0, m\) \(no value\) used as value */ (0, m)

	// built-ins
	_ = println // ERROR println \(built-in\) must be called

	// types
	_ = complex128 // ERROR complex128 \(type\) is not an expression

	// constants
	const c1 = 991
	const c2 float32 = 0.5
	const c3 = "foo"
	0 // ERROR 0 \(untyped int constant\) is not used
	0.5 // ERROR 0.5 \(untyped float constant\) is not used
	"foo" // ERROR "foo" \(untyped string constant\) is not used
	c1 // ERROR c1 \(untyped int constant 991\) is not used
	c2 // ERROR c2 \(constant 0.5 of type float32\) is not used
	c1 /* ERROR c1 \+ c2 \(constant 991.5 of type float32\) is not used */ + c2
	c3 // ERROR c3 \(untyped string constant "foo"\) is not used

	// variables
	x // ERROR x \(variable of type int\) is not used

	// values
	nil // ERROR nil is not used
	( /* ERROR \(\*int\)\(nil\) \(value of type \*int\) is not used */ *int)(nil)
	x /* ERROR x != x \(untyped bool value\) is not used */ != x
	x /* ERROR x \+ x \(value of type int\) is not used */ + x

	// value, ok's
	const s = "foo"
	m /* ERROR m\[s\] \(map index expression of type int\) is not used */ [s]
}

// Valid ERROR comments can have a variety of forms.
func _() {
	0 /* ERROR "0 .* is not used" */
	0 /* ERROR 0 .* is not used */
	0 // ERROR "0 .* is not used"
	0 // ERROR 0 .* is not used
}

// Don't report spurious errors as a consequence of earlier errors.
// Add more tests as needed.
func _() {
	if err := foo /* ERROR undeclared */ (); err != nil /* no error here */ {}
}

// Use unqualified names for package-local objects.
type T struct{}
var _ int = T /* ERROR value of type T */ {} // use T in error message rather then errors.T

// Don't report errors containing "invalid type" (issue #24182).
func _(x *missing /* ERROR undeclared name: missing */ ) {
	x.m() // there shouldn't be an error here referring to *invalid type
}