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259fd8adbb
In the previous CL, I had incorrectly removed one of the error messages from issue20232.go, because I thought go/constant was just handling it. But actually the compiler was panicking in nodlit, because it didn't handle constant.Unknown. So this CL makes it leave n.Type == nil for unknown constant.Values. While here, also address #42732 by making sure to report an error message when origConst is called with an unknown constant.Value (as can happen when multiplying two floating-point constants overflows). Finally, add OXOR and OBITNOT to the list of operations to report errors about, since they're also constant expressions that can produce a constant with a greater bit length than their operands. Fixes #42732. Change-Id: I4a538fbae9b3ac4c553d7de5625dc0c87d9acce3 Reviewed-on: https://go-review.googlesource.com/c/go/+/272928 Trust: Matthew Dempsky <mdempsky@google.com> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Russ Cox <rsc@golang.org>
33 lines
972 B
Go
33 lines
972 B
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 that large integer constant expressions cause overflow.
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// Does not compile.
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package main
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const (
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A int = 1
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B byte; // ERROR "type without expr|expected .=."
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)
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const LargeA = 1000000000000000000
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const LargeB = LargeA * LargeA * LargeA
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const LargeC = LargeB * LargeB * LargeB // GC_ERROR "constant multiplication overflow"
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const AlsoLargeA = LargeA << 400 << 400 >> 400 >> 400 // GC_ERROR "constant shift overflow"
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// Issue #42732.
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const a = 1e+500000000
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const b = a * a // ERROR "constant multiplication overflow"
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const c = b * b
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const MaxInt512 = (1<<256 - 1) * (1<<256 + 1)
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const _ = MaxInt512 + 1 // ERROR "constant addition overflow"
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const _ = MaxInt512 ^ -1 // ERROR "constant bitwise XOR overflow"
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const _ = ^MaxInt512 // ERROR "constant bitwise complement overflow"
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