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go/test/const1.go
Matthew Dempsky 9f6b21caea cmd/compile: fix ICE from invalid operations on float/complex constants
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>
2019-03-28 17:46:55 +00:00

95 lines
3.4 KiB
Go

// errorcheck
// Copyright 2009 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.
// Verify overflow is detected when using numeric constants.
// Does not compile.
package main
import "unsafe"
type I interface{}
const (
// assume all types behave similarly to int8/uint8
Int8 int8 = 101
Minus1 int8 = -1
Uint8 uint8 = 102
Const = 103
Float32 float32 = 104.5
Float64 float64 = 105.5
ConstFloat = 106.5
Big float64 = 1e300
String = "abc"
Bool = true
)
var (
a1 = Int8 * 100 // ERROR "overflow"
a2 = Int8 * -1 // OK
a3 = Int8 * 1000 // ERROR "overflow"
a4 = Int8 * int8(1000) // ERROR "overflow"
a5 = int8(Int8 * 1000) // ERROR "overflow"
a6 = int8(Int8 * int8(1000)) // ERROR "overflow"
a7 = Int8 - 2*Int8 - 2*Int8 // ERROR "overflow"
a8 = Int8 * Const / 100 // ERROR "overflow"
a9 = Int8 * (Const / 100) // OK
b1 = Uint8 * Uint8 // ERROR "overflow"
b2 = Uint8 * -1 // ERROR "overflow"
b3 = Uint8 - Uint8 // OK
b4 = Uint8 - Uint8 - Uint8 // ERROR "overflow"
b5 = uint8(^0) // ERROR "overflow"
b5a = int64(^0) // OK
b6 = ^uint8(0) // OK
b6a = ^int64(0) // OK
b7 = uint8(Minus1) // ERROR "overflow"
b8 = uint8(int8(-1)) // ERROR "overflow"
b8a = uint8(-1) // ERROR "overflow"
b9 byte = (1 << 10) >> 8 // OK
b10 byte = (1 << 10) // ERROR "overflow"
b11 byte = (byte(1) << 10) >> 8 // ERROR "overflow"
b12 byte = 1000 // ERROR "overflow"
b13 byte = byte(1000) // ERROR "overflow"
b14 byte = byte(100) * byte(100) // ERROR "overflow"
b15 byte = byte(100) * 100 // ERROR "overflow"
b16 byte = byte(0) * 1000 // ERROR "overflow"
b16a byte = 0 * 1000 // OK
b17 byte = byte(0) * byte(1000) // ERROR "overflow"
b18 byte = Uint8 / 0 // ERROR "division by zero"
c1 float64 = Big
c2 float64 = Big * Big // ERROR "overflow"
c3 float64 = float64(Big) * Big // ERROR "overflow"
c4 = Big * Big // ERROR "overflow"
c5 = Big / 0 // ERROR "division by zero"
c6 = 1000 % 1e3 // ERROR "invalid operation|expected integer type"
)
func f(int)
func main() {
f(Int8) // ERROR "convert|wrong type|cannot"
f(Minus1) // ERROR "convert|wrong type|cannot"
f(Uint8) // ERROR "convert|wrong type|cannot"
f(Const) // OK
f(Float32) // ERROR "convert|wrong type|cannot"
f(Float64) // ERROR "convert|wrong type|cannot"
f(ConstFloat) // ERROR "truncate"
f(ConstFloat - 0.5) // OK
f(Big) // ERROR "convert|wrong type|cannot"
f(String) // ERROR "convert|wrong type|cannot|incompatible"
f(Bool) // ERROR "convert|wrong type|cannot|incompatible"
}
const ptr = nil // ERROR "const.*nil"
const _ = string([]byte(nil)) // ERROR "is not a? ?constant"
const _ = uintptr(unsafe.Pointer((*int)(nil))) // ERROR "is not a? ?constant"
const _ = unsafe.Pointer((*int)(nil)) // ERROR "cannot be nil|invalid constant type|is not a constant"
const _ = (*int)(nil) // ERROR "cannot be nil|invalid constant type|is not a constant"