| // 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) |
| } |
| } |