blob: 39461145e99b1afd9eb06326d7541bc7022643e9 [file] [log] [blame]
// 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.pl.
package main
import (
"bytes"
"fmt"
"log"
"os"
"strings"
)
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)
in1, err := os.ReadFile(syscallFilename)
if err != nil {
log.Fatalf("can't open syscall file: %s", err)
}
in2, err := os.ReadFile(syscallArchFilename)
if err != nil {
log.Fatalf("can't open syscall file: %s", err)
}
in3, err := os.ReadFile("z" + syscallArchFilename)
if err != nil {
log.Fatalf("can't open syscall file: %s", err)
}
in := string(in1) + string(in2) + string(in3)
trampolines := map[string]bool{}
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, "#include \"textflag.h\"\n")
for _, line := range strings.Split(in, "\n") {
if !strings.HasPrefix(line, "func ") || !strings.HasSuffix(line, "_trampoline()") {
continue
}
fn := line[5 : len(line)-13]
if !trampolines[fn] {
trampolines[fn] = true
// The trampolines are ABIInternal as they are address-taken in Go code.
fmt.Fprintf(&out, "TEXT ยท%s_trampoline<ABIInternal>(SB),NOSPLIT,$0-0\n", fn)
fmt.Fprintf(&out, "\tJMP\t%s(SB)\n", fn)
}
}
err = os.WriteFile(fmt.Sprintf("zsyscall_%s_%s.s", goos, arch), out.Bytes(), 0644)
if err != nil {
log.Fatalf("can't write syscall file: %s", err)
}
}