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https://github.com/golang/go
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Expressions involving nil, even if they can be evaluated at compile time, do not count as Go constants and cannot be used in const initializers. Fixes #4673. Fixes #4680. R=ken2 CC=golang-dev https://golang.org/cl/7278043
95 lines
3.3 KiB
Go
95 lines
3.3 KiB
Go
// errorcheck
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// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Verify overflow is detected when using numeric constants.
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// Does not compile.
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package main
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import "unsafe"
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type I interface{}
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const (
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// assume all types behave similarly to int8/uint8
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Int8 int8 = 101
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Minus1 int8 = -1
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Uint8 uint8 = 102
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Const = 103
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Float32 float32 = 104.5
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Float64 float64 = 105.5
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ConstFloat = 106.5
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Big float64 = 1e300
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String = "abc"
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Bool = true
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)
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var (
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a1 = Int8 * 100 // ERROR "overflow"
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a2 = Int8 * -1 // OK
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a3 = Int8 * 1000 // ERROR "overflow"
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a4 = Int8 * int8(1000) // ERROR "overflow"
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a5 = int8(Int8 * 1000) // ERROR "overflow"
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a6 = int8(Int8 * int8(1000)) // ERROR "overflow"
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a7 = Int8 - 2*Int8 - 2*Int8 // ERROR "overflow"
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a8 = Int8 * Const / 100 // ERROR "overflow"
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a9 = Int8 * (Const / 100) // OK
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b1 = Uint8 * Uint8 // ERROR "overflow"
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b2 = Uint8 * -1 // ERROR "overflow"
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b3 = Uint8 - Uint8 // OK
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b4 = Uint8 - Uint8 - Uint8 // ERROR "overflow"
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b5 = uint8(^0) // ERROR "overflow"
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b5a = int64(^0) // OK
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b6 = ^uint8(0) // OK
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b6a = ^int64(0) // OK
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b7 = uint8(Minus1) // ERROR "overflow"
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b8 = uint8(int8(-1)) // ERROR "overflow"
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b8a = uint8(-1) // ERROR "overflow"
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b9 byte = (1 << 10) >> 8 // OK
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b10 byte = (1 << 10) // ERROR "overflow"
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b11 byte = (byte(1) << 10) >> 8 // ERROR "overflow"
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b12 byte = 1000 // ERROR "overflow"
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b13 byte = byte(1000) // ERROR "overflow"
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b14 byte = byte(100) * byte(100) // ERROR "overflow"
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b15 byte = byte(100) * 100 // ERROR "overflow"
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b16 byte = byte(0) * 1000 // ERROR "overflow"
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b16a byte = 0 * 1000 // OK
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b17 byte = byte(0) * byte(1000) // ERROR "overflow"
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b18 byte = Uint8 / 0 // ERROR "division by zero"
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c1 float64 = Big
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c2 float64 = Big * Big // ERROR "overflow"
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c3 float64 = float64(Big) * Big // ERROR "overflow"
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c4 = Big * Big // ERROR "overflow"
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c5 = Big / 0 // ERROR "division by zero"
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c6 = 1000 % 1e3 // ERROR "floating-point % operation|expected integer type"
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)
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func f(int)
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func main() {
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f(Int8) // ERROR "convert|wrong type|cannot"
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f(Minus1) // ERROR "convert|wrong type|cannot"
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f(Uint8) // ERROR "convert|wrong type|cannot"
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f(Const) // OK
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f(Float32) // ERROR "convert|wrong type|cannot"
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f(Float64) // ERROR "convert|wrong type|cannot"
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f(ConstFloat) // ERROR "truncate"
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f(ConstFloat - 0.5) // OK
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f(Big) // ERROR "convert|wrong type|cannot"
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f(String) // ERROR "convert|wrong type|cannot|incompatible"
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f(Bool) // ERROR "convert|wrong type|cannot|incompatible"
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}
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const ptr = nil // ERROR "const.*nil"
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const _ = string([]byte(nil)) // ERROR "is not a constant"
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const _ = uintptr(unsafe.Pointer((*int)(nil))) // ERROR "is not a constant"
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const _ = unsafe.Pointer((*int)(nil)) // ERROR "cannot be nil"
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const _ = (*int)(nil) // ERROR "cannot be nil"
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