53 lines
1.3 KiB
Go
53 lines
1.3 KiB
Go
// Copyright 2024 The Libc 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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// Package libc is a partial reimplementation of C libc in pure Go.
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package libc // import "modernc.org/libc"
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import (
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"sync/atomic"
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"unsafe"
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"golang.org/x/exp/constraints"
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)
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func X__sync_add_and_fetch[T constraints.Integer](t *TLS, p uintptr, v T) T {
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switch unsafe.Sizeof(v) {
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case 4:
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return T(atomic.AddInt32((*int32)(unsafe.Pointer(p)), int32(v)))
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case 8:
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return T(atomic.AddInt64((*int64)(unsafe.Pointer(p)), int64(v)))
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default:
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panic(todo(""))
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}
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}
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func X__sync_sub_and_fetch[T constraints.Integer](t *TLS, p uintptr, v T) T {
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switch unsafe.Sizeof(v) {
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case 4:
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return T(atomic.AddInt32((*int32)(unsafe.Pointer(p)), -int32(v)))
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case 8:
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return T(atomic.AddInt64((*int64)(unsafe.Pointer(p)), -int64(v)))
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default:
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panic(todo(""))
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}
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}
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// GoString returns the value of a C string at s.
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func GoString(s uintptr) string {
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if s == 0 {
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return ""
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}
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p := s
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for *(*byte)(unsafe.Pointer(p)) != 0 {
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p++
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}
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return string(unsafe.Slice((*byte)(unsafe.Pointer(s)), p-s))
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}
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// GoBytes returns a byte slice from a C char* having length len bytes.
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func GoBytes(s uintptr, len int) []byte {
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return unsafe.Slice((*byte)(unsafe.Pointer(s)), len)
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}
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