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