1// Copyright 2014 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5//go:build ignore
6
7// Generate Windows callback assembly file.
8
9package main
10
11import (
12	"bytes"
13	"fmt"
14	"os"
15)
16
17const maxCallback = 2000
18
19func genasm386Amd64() {
20	var buf bytes.Buffer
21
22	buf.WriteString(`// Code generated by wincallback.go using 'go generate'. DO NOT EDIT.
23
24//go:build 386 || amd64
25
26#include "textflag.h"
27
28// runtime·callbackasm is called by external code to
29// execute Go implemented callback function. It is not
30// called from the start, instead runtime·compilecallback
31// always returns address into runtime·callbackasm offset
32// appropriately so different callbacks start with different
33// CALL instruction in runtime·callbackasm. This determines
34// which Go callback function is executed later on.
35
36TEXT runtime·callbackasm(SB),NOSPLIT|NOFRAME,$0
37`)
38	for i := 0; i < maxCallback; i++ {
39		buf.WriteString("\tCALL\truntime·callbackasm1(SB)\n")
40	}
41
42	filename := fmt.Sprintf("zcallback_windows.s")
43	err := os.WriteFile(filename, buf.Bytes(), 0666)
44	if err != nil {
45		fmt.Fprintf(os.Stderr, "wincallback: %s\n", err)
46		os.Exit(2)
47	}
48}
49
50func genasmArm() {
51	var buf bytes.Buffer
52
53	buf.WriteString(`// Code generated by wincallback.go using 'go generate'. DO NOT EDIT.
54
55// External code calls into callbackasm at an offset corresponding
56// to the callback index. Callbackasm is a table of MOV and B instructions.
57// The MOV instruction loads R12 with the callback index, and the
58// B instruction branches to callbackasm1.
59// callbackasm1 takes the callback index from R12 and
60// indexes into an array that stores information about each callback.
61// It then calls the Go implementation for that callback.
62#include "textflag.h"
63
64TEXT runtime·callbackasm(SB),NOSPLIT|NOFRAME,$0
65`)
66	for i := 0; i < maxCallback; i++ {
67		fmt.Fprintf(&buf, "\tMOVW\t$%d, R12\n", i)
68		buf.WriteString("\tB\truntime·callbackasm1(SB)\n")
69	}
70
71	err := os.WriteFile("zcallback_windows_arm.s", buf.Bytes(), 0666)
72	if err != nil {
73		fmt.Fprintf(os.Stderr, "wincallback: %s\n", err)
74		os.Exit(2)
75	}
76}
77
78func genasmArm64() {
79	var buf bytes.Buffer
80
81	buf.WriteString(`// Code generated by wincallback.go using 'go generate'. DO NOT EDIT.
82
83// External code calls into callbackasm at an offset corresponding
84// to the callback index. Callbackasm is a table of MOV and B instructions.
85// The MOV instruction loads R12 with the callback index, and the
86// B instruction branches to callbackasm1.
87// callbackasm1 takes the callback index from R12 and
88// indexes into an array that stores information about each callback.
89// It then calls the Go implementation for that callback.
90#include "textflag.h"
91
92TEXT runtime·callbackasm(SB),NOSPLIT|NOFRAME,$0
93`)
94	for i := 0; i < maxCallback; i++ {
95		fmt.Fprintf(&buf, "\tMOVD\t$%d, R12\n", i)
96		buf.WriteString("\tB\truntime·callbackasm1(SB)\n")
97	}
98
99	err := os.WriteFile("zcallback_windows_arm64.s", buf.Bytes(), 0666)
100	if err != nil {
101		fmt.Fprintf(os.Stderr, "wincallback: %s\n", err)
102		os.Exit(2)
103	}
104}
105
106func gengo() {
107	var buf bytes.Buffer
108
109	fmt.Fprintf(&buf, `// Code generated by wincallback.go using 'go generate'. DO NOT EDIT.
110
111package runtime
112
113const cb_max = %d // maximum number of windows callbacks allowed
114`, maxCallback)
115	err := os.WriteFile("zcallback_windows.go", buf.Bytes(), 0666)
116	if err != nil {
117		fmt.Fprintf(os.Stderr, "wincallback: %s\n", err)
118		os.Exit(2)
119	}
120}
121
122func main() {
123	genasm386Amd64()
124	genasmArm()
125	genasmArm64()
126	gengo()
127}
128