github.com/m10x/go/src@v0.0.0-20220112094212-ba61592315da/runtime/wincallback.go (about) 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 9 package main 10 11 import ( 12 "bytes" 13 "fmt" 14 "os" 15 ) 16 17 const maxCallback = 2000 18 19 func 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 // 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 34 TEXT 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 := os.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 48 func 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 62 TEXT 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 := os.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 76 func genasmArm64() { 77 var buf bytes.Buffer 78 79 buf.WriteString(`// Code generated by wincallback.go using 'go generate'. DO NOT EDIT. 80 81 // External code calls into callbackasm at an offset corresponding 82 // to the callback index. Callbackasm is a table of MOV and B instructions. 83 // The MOV instruction loads R12 with the callback index, and the 84 // B instruction branches to callbackasm1. 85 // callbackasm1 takes the callback index from R12 and 86 // indexes into an array that stores information about each callback. 87 // It then calls the Go implementation for that callback. 88 #include "textflag.h" 89 90 TEXT runtime·callbackasm(SB),NOSPLIT|NOFRAME,$0 91 `) 92 for i := 0; i < maxCallback; i++ { 93 buf.WriteString(fmt.Sprintf("\tMOVD\t$%d, R12\n", i)) 94 buf.WriteString("\tB\truntime·callbackasm1(SB)\n") 95 } 96 97 err := os.WriteFile("zcallback_windows_arm64.s", buf.Bytes(), 0666) 98 if err != nil { 99 fmt.Fprintf(os.Stderr, "wincallback: %s\n", err) 100 os.Exit(2) 101 } 102 } 103 104 func gengo() { 105 var buf bytes.Buffer 106 107 buf.WriteString(fmt.Sprintf(`// Code generated by wincallback.go using 'go generate'. DO NOT EDIT. 108 109 package runtime 110 111 const cb_max = %d // maximum number of windows callbacks allowed 112 `, maxCallback)) 113 err := os.WriteFile("zcallback_windows.go", buf.Bytes(), 0666) 114 if err != nil { 115 fmt.Fprintf(os.Stderr, "wincallback: %s\n", err) 116 os.Exit(2) 117 } 118 } 119 120 func main() { 121 genasm386Amd64() 122 genasmArm() 123 genasmArm64() 124 gengo() 125 }