// errorcheck // Copyright 2020 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 p import "unsafe" const C = 1 var x, x1, x2 int var b bool var s string var c chan int var cp complex128 var slice []int var array [2]int var bytes []byte var runes []rune var r rune func f0() {} func f1() int { return 1 } func f2() (int, int) { return 1, 1 } type T struct{ X int } func (T) M1() int { return 1 } func (T) M0() {} func (T) M() {} var t T var tp *T type I interface{ M() } var i I var m map[int]int func _() { // Note: if the next line changes to x, the error silences the x+x etc below! x1 // ERROR "x1 evaluated but not used" nil // ERROR "nil evaluated but not used" C // ERROR "C evaluated but not used" 1 // ERROR "1 evaluated but not used" x + x // ERROR "x \+ x evaluated but not used" x - x // ERROR "x - x evaluated but not used" x | x // ERROR "x \| x evaluated but not used" "a" + s // ERROR ".a. \+ s evaluated but not used" &x // ERROR "&x evaluated but not used" b && b // ERROR "b && b evaluated but not used" append(slice, 1) // ERROR "append\(slice, 1\) evaluated but not used" string(bytes) // ERROR "string\(bytes\) evaluated but not used" string(runes) // ERROR "string\(runes\) evaluated but not used" f0() // ok f1() // ok f2() // ok _ = f0() // ERROR "f0\(\) used as value" _ = f1() // ok _, _ = f2() // ok _ = f2() // ERROR "assignment mismatch: 1 variable but f2 returns 2 values" T.M0 // ERROR "T.M0 evaluated but not used" t.M0 // ERROR "t.M0 evaluated but not used" cap // ERROR "use of builtin cap not in function call" cap(slice) // ERROR "cap\(slice\) evaluated but not used" close(c) // ok _ = close(c) // ERROR "close\(c\) used as value" func() {} // ERROR "func literal evaluated but not used" X{} // ERROR "undefined: X" map[string]int{} // ERROR "map\[string\]int{} evaluated but not used" struct{}{} // ERROR "struct ?{}{} evaluated but not used" [1]int{} // ERROR "\[1\]int{} evaluated but not used" []int{} // ERROR "\[\]int{} evaluated but not used" &struct{}{} // ERROR "&struct ?{}{} evaluated but not used" float32(x) // ERROR "float32\(x\) evaluated but not used" I(t) // ERROR "I\(t\) evaluated but not used" int(x) // ERROR "int\(x\) evaluated but not used" copy(slice, slice) // ok _ = copy(slice, slice) // ok delete(m, 1) // ok _ = delete(m, 1) // ERROR "delete\(m, 1\) used as value" t.X // ERROR "t.X evaluated but not used" tp.X // ERROR "tp.X evaluated but not used" t.M // ERROR "t.M evaluated but not used" I.M // ERROR "I.M evaluated but not used" i.(T) // ERROR "i.\(T\) evaluated but not used" x == x // ERROR "x == x evaluated but not used" x != x // ERROR "x != x evaluated but not used" x != x // ERROR "x != x evaluated but not used" x < x // ERROR "x < x evaluated but not used" x >= x // ERROR "x >= x evaluated but not used" x > x // ERROR "x > x evaluated but not used" *tp // ERROR "\*tp evaluated but not used" slice[0] // ERROR "slice\[0\] evaluated but not used" m[1] // ERROR "m\[1\] evaluated but not used" len(slice) // ERROR "len\(slice\) evaluated but not used" make(chan int) // ERROR "make\(chan int\) evaluated but not used" make(map[int]int) // ERROR "make\(map\[int\]int\) evaluated but not used" make([]int, 1) // ERROR "make\(\[\]int, 1\) evaluated but not used" x * x // ERROR "x \* x evaluated but not used" x / x // ERROR "x / x evaluated but not used" x % x // ERROR "x % x evaluated but not used" x << x // ERROR "x << x evaluated but not used" x >> x // ERROR "x >> x evaluated but not used" x & x // ERROR "x & x evaluated but not used" x &^ x // ERROR "x &\^ x evaluated but not used" new(int) // ERROR "new\(int\) evaluated but not used" !b // ERROR "!b evaluated but not used" ^x // ERROR "\^x evaluated but not used" +x // ERROR "\+x evaluated but not used" -x // ERROR "-x evaluated but not used" b || b // ERROR "b \|\| b evaluated but not used" panic(1) // ok _ = panic(1) // ERROR "panic\(1\) used as value" print(1) // ok _ = print(1) // ERROR "print\(1\) used as value" println(1) // ok _ = println(1) // ERROR "println\(1\) used as value" c <- 1 // ok slice[1:1] // ERROR "slice\[1:1\] evaluated but not used" array[1:1] // ERROR "array\[1:1\] evaluated but not used" s[1:1] // ERROR "s\[1:1\] evaluated but not used" slice[1:1:1] // ERROR "slice\[1:1:1\] evaluated but not used" array[1:1:1] // ERROR "array\[1:1:1\] evaluated but not used" recover() // ok <-c // ok string(r) // ERROR "string\(r\) evaluated but not used" iota // ERROR "undefined: iota" real(cp) // ERROR "real\(cp\) evaluated but not used" imag(cp) // ERROR "imag\(cp\) evaluated but not used" complex(1, 2) // ERROR "complex\(1, 2\) evaluated but not used" unsafe.Alignof(t.X) // ERROR "unsafe.Alignof\(t.X\) evaluated but not used" unsafe.Offsetof(t.X) // ERROR "unsafe.Offsetof\(t.X\) evaluated but not used" unsafe.Sizeof(t) // ERROR "unsafe.Sizeof\(t\) evaluated but not used" _ = int // ERROR "type int is not an expression" (x) // ERROR "x evaluated but not used" _ = new(x2) // ERROR "x2 is not a type" _ = new(1 + 1) // ERROR "1 \+ 1 is not a type" }