codekingpro/portable-devtools

1// errorcheck2 3// Copyright 2016 The Go Authors. All rights reserved.4// Use of this source code is governed by a BSD-style5// license that can be found in the LICENSE file.6 7// Verify that switch statements with duplicate cases are detected by the compiler.8// Does not compile.9 10package main11 12func f0(x int) {13	switch x {14	case 0:15	case 0: // ERROR "duplicate case (0 in switch)?"16	}17 18	switch x {19	case 0:20	case int(0): // ERROR "duplicate case (int.0. .value 0. in switch)?"21	}22}23 24func f1(x float32) {25	switch x {26	case 5:27	case 5: // ERROR "duplicate case (5 in switch)?"28	case 5.0: // ERROR "duplicate case (5 in switch)?"29	}30}31 32func f2(s string) {33	switch s {34	case "":35	case "": // ERROR "duplicate case (.. in switch)?"36	case "abc":37	case "abc": // ERROR "duplicate case (.abc. in switch)?"38	}39}40 41func f3(e interface{}) {42	switch e {43	case 0:44	case 0: // ERROR "duplicate case (0 in switch)?"45	case int64(0):46	case float32(10):47	case float32(10): // ERROR "duplicate case (float32\(10\) .value 10. in switch)?"48	case float64(10):49	case float64(10): // ERROR "duplicate case (float64\(10\) .value 10. in switch)?"50	}51}52 53func f5(a [1]int) {54	switch a {55	case [1]int{0}:56	case [1]int{0}: // OK -- see issue 1589657	}58}59 60// Ensure duplicate const bool clauses are accepted.61func f6() int {62	switch {63	case 0 == 0:64		return 065	case 1 == 1: // Intentionally OK, even though a duplicate of the above const true66		return 167	}68	return 269}70 71// Ensure duplicates in ranges are detected (issue #17517).72func f7(a int) {73	switch a {74	case 0:75	case 0, 1: // ERROR "duplicate case 0"76	case 1, 2, 3, 4: // ERROR "duplicate case 1"77	}78}79 80// Ensure duplicates with simple literals are printed as they were81// written, not just their values. Particularly useful for runes.82func f8(r rune) {83	const x = 1084	switch r {85	case 33, 33: // ERROR "duplicate case (33 in switch)?"86	case 34, '"': // ERROR "duplicate case '"' .value 34. in switch"87	case 35, rune('#'): // ERROR "duplicate case (rune.'#'. .value 35. in switch)?"88	case 36, rune(36): // ERROR "duplicate case (rune.36. .value 36. in switch)?"89	case 37, '$'+1: // ERROR "duplicate case ('\$' \+ 1 .value 37. in switch)?"90	case 'b':91	case 'a', 'b', 'c', 'd': // ERROR "duplicate case ('b' .value 98.)?"92	case x, x: // ERROR "duplicate case (x .value 10.)?"93	}94}95