1// SPDX-License-Identifier: Apache-2.0
2// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
3
4//go:build ignore
5
6package main
7
8import (
9 "bytes"
10 "fmt"
11 "go/format"
12 "log"
13 "os"
14 "strings"
15 "text/template"
16)
17
18const templateSymbols = `// Code generated by 'go generate' with gen.go. DO NOT EDIT.
19
20// SPDX-License-Identifier: Apache-2.0
21// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
22
23//go:build darwin || linux
24
25package fakecgo
26
27import (
28 "syscall"
29 "unsafe"
30)
31
32// setg_trampoline calls setg with the G provided
33func setg_trampoline(setg uintptr, G uintptr)
34
35//go:linkname memmove runtime.memmove
36func memmove(to, from unsafe.Pointer, n uintptr)
37
38// call5 takes fn the C function and 5 arguments and calls the function with those arguments
39func call5(fn, a1, a2, a3, a4, a5 uintptr) uintptr
40
41{{ range . -}}
42func {{.Name}}(
43{{- range .Args -}}
44 {{- if .Name -}}
45 {{.Name}} {{.Type}},
46 {{- end -}}
47{{- end -}}) {{.Return}} {
48 {{- if .Return -}}
49 {{- if eq .Return "unsafe.Pointer" -}}
50 ret :=
51 {{- else -}}
52 return {{.Return}}(
53 {{- end -}}
54 {{- end -}}
55call5({{.Name}}ABI0,
56{{- range .Args}}
57 {{- if .Name -}}
58 {{- if hasPrefix .Type "*" -}}
59 uintptr(unsafe.Pointer({{.Name}})),
60 {{- else -}}
61 uintptr({{.Name}}),
62 {{- end -}}
63 {{- else -}}
64 0,
65 {{- end -}}
66{{- end -}}
67 ) {{/* end of call5 */}}
68{{- if .Return -}}
69 {{- if eq .Return "unsafe.Pointer"}}
70 // this indirection is to avoid go vet complaining about possible misuse of unsafe.Pointer
71 return *(*unsafe.Pointer)(unsafe.Pointer(&ret))
72 {{- else -}}
73 ) {{/* end of cast */}}
74 {{- end -}}
75{{- end}}
76}
77
78{{end}}
79{{- range . }}
80//go:linkname _{{.Name}} _{{.Name}}
81var _{{.Name}} uintptr
82var {{.Name}}ABI0 = uintptr(unsafe.Pointer(&_{{.Name}}))
83{{ end }}
84`
85
86const templateTrampolinesStubs = `// Code generated by 'go generate' with gen.go. DO NOT EDIT.
87
88// SPDX-License-Identifier: Apache-2.0
89// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
90
91//go:build darwin || linux
92
93#include "textflag.h"
94
95// these stubs are here because it is not possible to go:linkname directly the C functions on darwin arm64
96{{ range . }}
97TEXT _{{.Name}}(SB), NOSPLIT|NOFRAME, $0-0
98 JMP purego_{{.Name}}(SB)
99 RET
100{{ end -}}
101`
102
103type Arg struct {
104 Name string
105 Type string
106}
107
108type Symbol struct {
109 Name string
110 Args [5]Arg
111 Return string
112}
113
114var (
115 libcSymbols = []Symbol{
116 {"malloc", [5]Arg{{"size", "uintptr"}}, "unsafe.Pointer"},
117 {"free", [5]Arg{{"ptr", "unsafe.Pointer"}}, ""},
118 {"setenv", [5]Arg{{"name", "*byte"}, {"value", "*byte"}, {"overwrite", "int32"}}, "int32"},
119 {"unsetenv", [5]Arg{{"name", "*byte"}}, "int32"},
120 {"sigfillset", [5]Arg{{"set", "*sigset_t"}}, "int32"},
121 {"nanosleep", [5]Arg{{"ts", "*syscall.Timespec"}, {"rem", "*syscall.Timespec"}}, "int32"},
122 {"abort", [5]Arg{}, ""},
123 }
124 pthreadSymbols = []Symbol{
125 {"pthread_attr_init", [5]Arg{{"attr", "*pthread_attr_t"}}, "int32"},
126 {"pthread_create", [5]Arg{{"thread", "*pthread_t"}, {"attr", "*pthread_attr_t"}, {"start", "unsafe.Pointer"}, {"arg", "unsafe.Pointer"}}, "int32"},
127 {"pthread_detach", [5]Arg{{"thread", "pthread_t"}}, "int32"},
128 {"pthread_sigmask", [5]Arg{{"how", "sighow"}, {"ign", "*sigset_t"}, {"oset", "*sigset_t"}}, "int32"},
129 {"pthread_self", [5]Arg{}, "pthread_t"},
130 {"pthread_get_stacksize_np", [5]Arg{{"thread", "pthread_t"}}, "size_t"},
131 {"pthread_attr_getstacksize", [5]Arg{{"attr", "*pthread_attr_t"}, {"stacksize", "*size_t"}}, "int32"},
132 {"pthread_attr_setstacksize", [5]Arg{{"attr", "*pthread_attr_t"}, {"size", "size_t"}}, "int32"},
133 {"pthread_attr_destroy", [5]Arg{{"attr", "*pthread_attr_t"}}, "int32"},
134 {"pthread_mutex_lock", [5]Arg{{"mutex", "*pthread_mutex_t"}}, "int32"},
135 {"pthread_mutex_unlock", [5]Arg{{"mutex", "*pthread_mutex_t"}}, "int32"},
136 {"pthread_cond_broadcast", [5]Arg{{"cond", "*pthread_cond_t"}}, "int32"},
137 {"pthread_setspecific", [5]Arg{{"key", "pthread_key_t"}, {"value", "unsafe.Pointer"}}, "int32"},
138 }
139)
140
141var funcs = map[string]any{
142 "hasPrefix": strings.HasPrefix,
143}
144
145func run() error {
146 t, err := template.New("symbol.go").Funcs(funcs).Parse(templateSymbols)
147 if err != nil {
148 return err
149 }
150 f, err := os.Create("symbols.go")
151 defer f.Close()
152 if err != nil {
153 return err
154 }
155 allSymbols := append(append([]Symbol{}, libcSymbols...), pthreadSymbols...)
156 buf := new(bytes.Buffer)
157 if err := t.Execute(buf, allSymbols); err != nil {
158 return err
159 }
160 source, err := format.Source(buf.Bytes())
161 if err != nil {
162 return err
163 }
164 if _, err = f.Write(source); err != nil {
165 return err
166 }
167 t, err = template.New("trampolines_stubs.s").Funcs(funcs).Parse(templateTrampolinesStubs)
168 if err != nil {
169 return err
170 }
171 f, err = os.Create("trampolines_stubs.s")
172 defer f.Close()
173 if err != nil {
174 return err
175 }
176 if err := t.Execute(f, allSymbols); err != nil {
177 return err
178 }
179 for _, goos := range []string{"darwin", "linux"} {
180 f, err = os.Create(fmt.Sprintf("symbols_%s.go", goos))
181 defer f.Close()
182 if err != nil {
183 return err
184 }
185 f.WriteString(`// Code generated by 'go generate' with gen.go. DO NOT EDIT.
186
187// SPDX-License-Identifier: Apache-2.0
188// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
189
190package fakecgo
191
192`)
193 const importPragma = `//go:cgo_import_dynamic purego_%s %s "%s"` + "\n"
194 libcSO := "/usr/lib/libSystem.B.dylib"
195 pthreadSO := "/usr/lib/libSystem.B.dylib"
196 if goos == "linux" {
197 libcSO = "libc.so.6"
198 pthreadSO = "libpthread.so.0"
199 }
200 for _, sym := range libcSymbols {
201 f.WriteString(fmt.Sprintf(importPragma, sym.Name, sym.Name, libcSO))
202 }
203 for _, sym := range pthreadSymbols {
204 f.WriteString(fmt.Sprintf(importPragma, sym.Name, sym.Name, pthreadSO))
205 }
206 }
207 return nil
208}
209
210func main() {
211 if err := run(); err != nil {
212 log.Fatal(err)
213 }
214}