strings.go RawHistoryFolder

1// SPDX-License-Identifier: Apache-2.0
2// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
3
4package strings
5
6import (
7	"unsafe"
8)
9
10// hasSuffix tests whether the string s ends with suffix.
11func hasSuffix(s, suffix string) bool {
12	return len(s) >= len(suffix) && s[len(s)-len(suffix):] == suffix
13}
14
15// CString converts a go string to *byte that can be passed to C code.
16func CString(name string) *byte {
17	if hasSuffix(name, "\x00") {
18		return &(*(*[]byte)(unsafe.Pointer(&name)))[0]
19	}
20	var b = make([]byte, len(name)+1)
21	copy(b, name)
22	return &b[0]
23}
24
25// GoString copies a char* to a Go string.
26func GoString(c uintptr) string {
27	// We take the address and then dereference it to trick go vet from creating a possible misuse of unsafe.Pointer
28	ptr := *(*unsafe.Pointer)(unsafe.Pointer(&c))
29	if ptr == nil {
30		return ""
31	}
32	var length int
33	for {
34		if *(*byte)(unsafe.Add(ptr, uintptr(length))) == '\x00' {
35			break
36		}
37		length++
38	}
39	return string(unsafe.Slice((*byte)(ptr), length))
40}