sys/unix/mkasm.go

141 строка
3.8 KiB
Go

// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build ignore
// +build ignore
// mkasm.go generates assembly trampolines to call library routines from Go.
// This program must be run after mksyscall.go.
package main
import (
"bytes"
"fmt"
"io/ioutil"
"log"
"os"
"sort"
"strings"
)
func archPtrSize(arch string) int {
switch arch {
case "386", "arm":
return 4
case "amd64", "arm64", "mips64", "ppc64", "riscv64":
return 8
default:
log.Fatalf("Unknown arch %q", arch)
return 0
}
}
func generateASMFile(goos, arch string, inFileNames []string, outFileName string) map[string]bool {
trampolines := map[string]bool{}
var orderedTrampolines []string
for _, inFileName := range inFileNames {
in, err := ioutil.ReadFile(inFileName)
if err != nil {
log.Fatalf("Failed to read file: %v", err)
}
for _, line := range strings.Split(string(in), "\n") {
const prefix = "var "
const suffix = "_trampoline_addr uintptr"
if !strings.HasPrefix(line, prefix) || !strings.HasSuffix(line, suffix) {
continue
}
fn := strings.TrimSuffix(strings.TrimPrefix(line, prefix), suffix)
if !trampolines[fn] {
orderedTrampolines = append(orderedTrampolines, fn)
trampolines[fn] = true
}
}
}
ptrSize := archPtrSize(arch)
var out bytes.Buffer
fmt.Fprintf(&out, "// go run mkasm.go %s\n", strings.Join(os.Args[1:], " "))
fmt.Fprintf(&out, "// Code generated by the command above; DO NOT EDIT.\n")
fmt.Fprintf(&out, "\n")
fmt.Fprintf(&out, "#include \"textflag.h\"\n")
for _, fn := range orderedTrampolines {
fmt.Fprintf(&out, "\nTEXT %s_trampoline<>(SB),NOSPLIT,$0-0\n", fn)
if goos == "openbsd" && arch == "ppc64" {
fmt.Fprintf(&out, "\tCALL\t%s(SB)\n", fn)
fmt.Fprintf(&out, "\tRET\n")
} else {
fmt.Fprintf(&out, "\tJMP\t%s(SB)\n", fn)
}
fmt.Fprintf(&out, "GLOBL\t·%s_trampoline_addr(SB), RODATA, $%d\n", fn, ptrSize)
fmt.Fprintf(&out, "DATA\t·%s_trampoline_addr(SB)/%d, $%s_trampoline<>(SB)\n", fn, ptrSize, fn)
}
if err := ioutil.WriteFile(outFileName, out.Bytes(), 0644); err != nil {
log.Fatalf("Failed to write assembly file %q: %v", outFileName, err)
}
return trampolines
}
const darwinTestTemplate = `// go run mkasm.go %s
// Code generated by the command above; DO NOT EDIT.
//go:build darwin && go1.12
// +build darwin,go1.12
package unix
// All the _trampoline functions in zsyscall_darwin_%s.s.
var darwinTests = [...]darwinTest{
%s}
`
func writeDarwinTest(trampolines map[string]bool, fileName, arch string) {
var sortedTrampolines []string
for fn := range trampolines {
sortedTrampolines = append(sortedTrampolines, fn)
}
sort.Strings(sortedTrampolines)
var out bytes.Buffer
const prefix = "libc_"
for _, fn := range sortedTrampolines {
fmt.Fprintf(&out, fmt.Sprintf("\t{%q, %s_trampoline_addr},\n", strings.TrimPrefix(fn, prefix), fn))
}
lines := out.String()
out.Reset()
fmt.Fprintf(&out, darwinTestTemplate, strings.Join(os.Args[1:], " "), arch, lines)
if err := ioutil.WriteFile(fileName, out.Bytes(), 0644); err != nil {
log.Fatalf("Failed to write test file %q: %v", fileName, err)
}
}
func main() {
if len(os.Args) != 3 {
log.Fatalf("Usage: %s <goos> <arch>", os.Args[0])
}
goos, arch := os.Args[1], os.Args[2]
syscallFilename := fmt.Sprintf("syscall_%s.go", goos)
syscallArchFilename := fmt.Sprintf("syscall_%s_%s.go", goos, arch)
zsyscallArchFilename := fmt.Sprintf("zsyscall_%s_%s.go", goos, arch)
zsyscallASMFileName := fmt.Sprintf("zsyscall_%s_%s.s", goos, arch)
inFileNames := []string{
syscallFilename,
syscallArchFilename,
zsyscallArchFilename,
}
trampolines := generateASMFile(goos, arch, inFileNames, zsyscallASMFileName)
if goos == "darwin" {
writeDarwinTest(trampolines, fmt.Sprintf("darwin_%s_test.go", arch), arch)
}
}