| // 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 vardecl |
| |
| // Prerequisites. |
| import "math" |
| func f() {} |
| func g() (x, y int) { return } |
| var m map[string]int |
| |
| // Var decls must have a type or an initializer. |
| var _ int |
| var _, _ int |
| |
| var _; /* ERROR "expected type" */ |
| var _, _; /* ERROR "expected type" */ |
| var _, _, _; /* ERROR "expected type" */ |
| |
| // The initializer must be an expression. |
| var _ = int /* ERROR "not an expression" */ |
| var _ = f /* ERROR "used as value" */ () |
| |
| // Identifier and expression arity must match. |
| var _, _ = 1, 2 |
| var _ = 1, 2 /* ERROR "extra init expr 2" */ |
| var _, _ = 1 /* ERRORx `assignment mismatch: [1-9]+ variables but.*[1-9]+ value(s)?` */ |
| var _, _, _ /* ERROR "missing init expr for _" */ = 1, 2 |
| |
| var _ = g /* ERROR "multiple-value g" */ () |
| var _, _ = g() |
| var _, _, _ = g /* ERRORx `assignment mismatch: [1-9]+ variables but.*[1-9]+ value(s)?` */ () |
| |
| var _ = m["foo"] |
| var _, _ = m["foo"] |
| var _, _, _ = m /* ERRORx `assignment mismatch: [1-9]+ variables but.*[1-9]+ value(s)?` */ ["foo"] |
| |
| var _, _ int = 1, 2 |
| var _ int = 1, 2 /* ERROR "extra init expr 2" */ |
| var _, _ int = 1 /* ERRORx `assignment mismatch: [1-9]+ variables but.*[1-9]+ value(s)?` */ |
| var _, _, _ /* ERROR "missing init expr for _" */ int = 1, 2 |
| |
| var ( |
| _, _ = 1, 2 |
| _ = 1, 2 /* ERROR "extra init expr 2" */ |
| _, _ = 1 /* ERRORx `assignment mismatch: [1-9]+ variables but.*[1-9]+ value(s)?` */ |
| _, _, _ /* ERROR "missing init expr for _" */ = 1, 2 |
| |
| _ = g /* ERROR "multiple-value g" */ () |
| _, _ = g() |
| _, _, _ = g /* ERRORx `assignment mismatch: [1-9]+ variables but.*[1-9]+ value(s)?` */ () |
| |
| _ = m["foo"] |
| _, _ = m["foo"] |
| _, _, _ = m /* ERRORx `assignment mismatch: [1-9]+ variables but.*[1-9]+ value(s)?` */ ["foo"] |
| |
| _, _ int = 1, 2 |
| _ int = 1, 2 /* ERROR "extra init expr 2" */ |
| _, _ int = 1 /* ERRORx `assignment mismatch: [1-9]+ variables but.*[1-9]+ value(s)?` */ |
| _, _, _ /* ERROR "missing init expr for _" */ int = 1, 2 |
| ) |
| |
| // Variables declared in function bodies must be 'used'. |
| type T struct{} |
| func (r T) _(a, b, c int) (u, v, w int) { |
| var x1 /* ERROR "declared and not used" */ int |
| var x2 /* ERROR "declared and not used" */ int |
| x1 = 1 |
| (x2) = 2 |
| |
| y1 /* ERROR "declared and not used" */ := 1 |
| y2 /* ERROR "declared and not used" */ := 2 |
| y1 = 1 |
| (y1) = 2 |
| |
| { |
| var x1 /* ERROR "declared and not used" */ int |
| var x2 /* ERROR "declared and not used" */ int |
| x1 = 1 |
| (x2) = 2 |
| |
| y1 /* ERROR "declared and not used" */ := 1 |
| y2 /* ERROR "declared and not used" */ := 2 |
| y1 = 1 |
| (y1) = 2 |
| } |
| |
| if x /* ERROR "declared and not used" */ := 0; a < b {} |
| |
| switch x /* ERROR "declared and not used" */, y := 0, 1; a { |
| case 0: |
| _ = y |
| case 1: |
| x /* ERROR "declared and not used" */ := 0 |
| } |
| |
| var t interface{} |
| switch t /* ERROR "declared and not used" */ := t.(type) {} |
| |
| switch t /* ERROR "declared and not used" */ := t.(type) { |
| case int: |
| } |
| |
| switch t /* ERROR "declared and not used" */ := t.(type) { |
| case int: |
| case float32, complex64: |
| t = nil |
| } |
| |
| switch t := t.(type) { |
| case int: |
| case float32, complex64: |
| _ = t |
| } |
| |
| switch t := t.(type) { |
| case int: |
| case float32: |
| case string: |
| _ = func() string { |
| return t |
| } |
| } |
| |
| switch t := t; t /* ERROR "declared and not used" */ := t.(type) {} |
| |
| var z1 /* ERROR "declared and not used" */ int |
| var z2 int |
| _ = func(a, b, c int) (u, v, w int) { |
| z1 = a |
| (z1) = b |
| a = z2 |
| return |
| } |
| |
| var s []int |
| var i /* ERROR "declared and not used" */ , j int |
| for i, j = range s { |
| _ = j |
| } |
| |
| for i, j /* ERROR "declared and not used" */ := range s { |
| _ = func() int { |
| return i |
| } |
| } |
| return |
| } |
| |
| // Unused variables in function literals must lead to only one error (issue #22524). |
| func _() { |
| _ = func() { |
| var x /* ERROR "declared and not used" */ int |
| } |
| } |
| |
| // Invalid variable declarations must not lead to "declared and not used errors". |
| // TODO(gri) enable these tests once go/types follows types2 logic for declared and not used variables |
| // func _() { |
| // var a x // DISABLED_ERROR undefined: x |
| // var b = x // DISABLED_ERROR undefined: x |
| // var c int = x // DISABLED_ERROR undefined: x |
| // var d, e, f x /* DISABLED_ERROR x */ /* DISABLED_ERROR x */ /* DISABLED_ERROR x */ |
| // var g, h, i = x, x, x /* DISABLED_ERROR x */ /* DISABLED_ERROR x */ /* DISABLED_ERROR x */ |
| // var j, k, l float32 = x, x, x /* DISABLED_ERROR x */ /* DISABLED_ERROR x */ /* DISABLED_ERROR x */ |
| // // but no "declared and not used" errors |
| // } |
| |
| // Invalid (unused) expressions must not lead to spurious "declared and not used errors". |
| func _() { |
| var a, b, c int |
| var x, y int |
| x, y = a /* ERRORx `assignment mismatch: [1-9]+ variables but.*[1-9]+ value(s)?` */ , b, c |
| _ = x |
| _ = y |
| } |
| |
| func _() { |
| var x int |
| return x /* ERROR "too many return values" */ |
| return math /* ERROR "too many return values" */ .Sin(0) |
| } |
| |
| func _() int { |
| var x, y int |
| return x, y /* ERROR "too many return values" */ |
| } |
| |
| // Short variable declarations must declare at least one new non-blank variable. |
| func _() { |
| _ := /* ERROR "no new variables" */ 0 |
| _, a := 0, 1 |
| _, a := /* ERROR "no new variables" */ 0, 1 |
| _, a, b := 0, 1, 2 |
| _, _, _ := /* ERROR "no new variables" */ 0, 1, 2 |
| |
| _ = a |
| _ = b |
| } |
| |
| // Test case for variables depending on function literals (see also #22992). |
| var A /* ERROR "initialization cycle" */ = func() int { return A }() |
| |
| func _() { |
| // The function literal below must not see a. |
| var a = func() int { return a /* ERROR "undefined" */ }() |
| var _ = func() int { return a }() |
| |
| // The function literal below must not see x, y, or z. |
| var x, y, z = 0, 1, func() int { return x /* ERROR "undefined" */ + y /* ERROR "undefined" */ + z /* ERROR "undefined" */ }() |
| _, _, _ = x, y, z |
| } |
| |
| // TODO(gri) consolidate other var decl checks in this file |