mirror of
https://github.com/golang/go
synced 2024-11-26 22:51:23 -07:00
9f6b21caea
Typechecking treats all untyped numbers as integers for the purposes of validating operators. However, when I refactoring constant operation evalution in golang.org/cl/139901, I mistakenly interpreted that the only invalid case that needed to be preserved was % (modulo) on floating-point values. This CL restores the other remaining cases that were dropped from that CL. It also uses the phrasing "invalid operation" instead of "illegal constant expression" for better consistency with the rest of cmd/compile and with go/types. Lastly, this CL extends setconst to recognize failed constant folding (e.g., division by zero) so that we can properly mark those expressions as broken rather than continuing forward with bogus values that might lead to further spurious errors. Fixes #31060. Change-Id: I1ab6491371925e22bc8b95649f1a0eed010abca6 Reviewed-on: https://go-review.googlesource.com/c/go/+/169719 Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
95 lines
3.4 KiB
Go
95 lines
3.4 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 "invalid 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|invalid constant type|is not a constant"
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const _ = (*int)(nil) // ERROR "cannot be nil|invalid constant type|is not a constant"
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