test/defererrcheck.go

   1 // errorcheck -0 -l -d=defer
   2
   3 // Copyright 2019 The Go Authors. All rights reserved.
   4 // Use of this source code is governed by a BSD-style
   5 // license that can be found in the LICENSE file.
   6
   7 // check that open-coded defers are used in expected situations
   8
   9 package main
  10
  11 import "fmt"
  12
  13 var glob = 3
  14
  15 func f1() {
  16
  17         for i := 0; i < 10; i++ {
  18                 fmt.Println("loop")
  19         }
  20         defer func() { // ERROR "open-coded defer"
  21                 fmt.Println("defer")
  22         }()
  23 }
  24
  25 func f2() {
  26         for {
  27                 defer func() { // ERROR "heap-allocated defer"
  28                         fmt.Println("defer1")
  29                 }()
  30                 if glob > 2 {
  31                         break
  32                 }
  33         }
  34         defer func() { // ERROR "stack-allocated defer"
  35                 fmt.Println("defer2")
  36         }()
  37 }
  38
  39 func f3() {
  40         defer func() { // ERROR "stack-allocated defer"
  41                 fmt.Println("defer2")
  42         }()
  43         for {
  44                 defer func() { // ERROR "heap-allocated defer"
  45                         fmt.Println("defer1")
  46                 }()
  47                 if glob > 2 {
  48                         break
  49                 }
  50         }
  51 }
  52
  53 func f4() {
  54         defer func() { // ERROR "open-coded defer"
  55                 fmt.Println("defer")
  56         }()
  57 label:
  58         fmt.Println("goto loop")
  59         if glob > 2 {
  60                 goto label
  61         }
  62 }
  63
  64 func f5() {
  65 label:
  66         fmt.Println("goto loop")
  67         defer func() { // ERROR "heap-allocated defer"
  68                 fmt.Println("defer")
  69         }()
  70         if glob > 2 {
  71                 goto label
  72         }
  73 }
  74
  75 func f6() {
  76 label:
  77         fmt.Println("goto loop")
  78         if glob > 2 {
  79                 goto label
  80         }
  81         // The current analysis doesn't end a backward goto loop, so this defer is
  82         // considered to be inside a loop
  83         defer func() { // ERROR "heap-allocated defer"
  84                 fmt.Println("defer")
  85         }()
  86 }