35 lines
1.5 KiB
Go
35 lines
1.5 KiB
Go
// Copyright 2020 Brad Fitzpatrick. 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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// Package go4.org/unsafe/assume-no-moving-gc exists so you can depend
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// on it from unsafe code that wants to declare that it assumes that
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// the Go runtime does not using a moving garbage collector. Specifically,
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// it asserts that the caller is playing stupid games with the addresses
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// of heap-allocated values. It says nothing about values that Go's escape
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// analysis keeps on the stack. Ensuring things aren't stack-allocated
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// is the caller's responsibility.
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//
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// This package is then updated for new Go versions when that
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// is still the case and explodes at runtime with a failure
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// otherwise, unless an environment variable overrides it.
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//
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// To use:
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//
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// import _ "go4.org/unsafe/assume-no-moving-gc"
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//
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// There is no API.
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//
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// It is intentional that this package will break code that's not updated
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// regularly to double check its assumptions about the world and new Go
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// versions. If you play stupid games with unsafe pointers, the stupid prize
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// is this maintenance cost. (The alternative would be memory corruption if
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// some unmaintained, unsafe library were built with a future version of Go
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// that worked very differently than when the unsafe library was built.)
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// Ideally you shouldn't write unsafe code, though.
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//
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// The GitHub repo is at https://github.com/go4org/unsafe-assume-no-moving-gc
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package assume_no_moving_gc
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const env = "ASSUME_NO_MOVING_GC_UNSAFE_RISK_IT_WITH"
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