tools/llvm-go/llvm-go.go

   1 //===-- llvm-go.go - go tool wrapper for LLVM -----------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This tool lets us build LLVM components within the tree by setting up a
  10 // $GOPATH that resembles a tree fetched in the normal way with "go get".
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 package main
  15
  16 import (
  17         "fmt"
  18         "io/ioutil"
  19         "os"
  20         "os/exec"
  21         "path/filepath"
  22         "runtime"
  23         "strings"
  24 )
  25
  26 const (
  27         linkmodeComponentLibs = "component-libs"
  28         linkmodeDylib         = "dylib"
  29 )
  30
  31 type pkg struct {
  32         llvmpath, pkgpath string
  33 }
  34
  35 var packages = []pkg{
  36         {"bindings/go/llvm", "llvm.org/llvm/bindings/go/llvm"},
  37 }
  38
  39 type compilerFlags struct {
  40         cpp, cxx, ld string
  41 }
  42
  43 var components = []string{
  44         "all-targets",
  45         "analysis",
  46         "asmparser",
  47         "asmprinter",
  48         "bitreader",
  49         "bitwriter",
  50         "codegen",
  51         "core",
  52         "coroutines",
  53         "debuginfodwarf",
  54         "executionengine",
  55         "instrumentation",
  56         "interpreter",
  57         "ipo",
  58         "irreader",
  59         "linker",
  60         "mc",
  61         "mcjit",
  62         "objcarcopts",
  63         "option",
  64         "profiledata",
  65         "scalaropts",
  66         "support",
  67         "target",
  68 }
  69
  70 func llvmConfig(args ...string) string {
  71         configpath := os.Getenv("LLVM_CONFIG")
  72         if configpath == "" {
  73                 bin, _ := filepath.Split(os.Args[0])
  74                 configpath = filepath.Join(bin, "llvm-config")
  75         }
  76
  77         cmd := exec.Command(configpath, args...)
  78         cmd.Stderr = os.Stderr
  79         out, err := cmd.Output()
  80         if err != nil {
  81                 panic(err.Error())
  82         }
  83
  84         outstr := string(out)
  85         outstr = strings.TrimSuffix(outstr, "\n")
  86         outstr = strings.Replace(outstr, "\n", " ", -1)
  87         return outstr
  88 }
  89
  90 func llvmFlags() compilerFlags {
  91         args := append([]string{"--ldflags", "--libs", "--system-libs"}, components...)
  92         ldflags := llvmConfig(args...)
  93         stdLibOption := ""
  94         if strings.Contains(llvmConfig("--cxxflags"), "-stdlib=libc++") {
  95                 // If libc++ is used to build LLVM libraries, -stdlib=libc++ is
  96                 // needed to resolve dependent symbols
  97                 stdLibOption = "-stdlib=libc++"
  98         }
  99         if runtime.GOOS != "darwin" {
 100                 // OS X doesn't like -rpath with cgo. See:
 101                 // https://github.com/golang/go/issues/7293
 102                 ldflags = "-Wl,-rpath," + llvmConfig("--libdir") + " " + ldflags
 103         }
 104         return compilerFlags{
 105                 cpp: llvmConfig("--cppflags"),
 106                 cxx: "-std=c++14" + " " + stdLibOption,
 107                 ld:  ldflags,
 108         }
 109 }
 110
 111 func addTag(args []string, tag string) []string {
 112         args = append([]string{}, args...)
 113         addedTag := false
 114         for i, a := range args {
 115                 if strings.HasPrefix(a, "-tags=") {
 116                         args[i] = a + " " + tag
 117                         addedTag = true
 118                 } else if a == "-tags" && i+1 < len(args) {
 119                         args[i+1] = args[i+1] + " " + tag
 120                         addedTag = true
 121                 }
 122         }
 123         if !addedTag {
 124                 args = append([]string{args[0], "-tags", tag}, args[1:]...)
 125         }
 126         return args
 127 }
 128
 129 func printComponents() {
 130         fmt.Println(strings.Join(components, " "))
 131 }
 132
 133 func printConfig() {
 134         flags := llvmFlags()
 135
 136         fmt.Printf(`// +build !byollvm
 137
 138 // This file is generated by llvm-go, do not edit.
 139
 140 package llvm
 141
 142 /*
 143 #cgo CPPFLAGS: %s
 144 #cgo CXXFLAGS: %s
 145 #cgo LDFLAGS: %s
 146 */
 147 import "C"
 148
 149 type (run_build_sh int)
 150 `, flags.cpp, flags.cxx, flags.ld)
 151 }
 152
 153 func runGoWithLLVMEnv(args []string, cc, cxx, gocmd, llgo, cppflags, cxxflags, ldflags string, packages []pkg) {
 154         args = addTag(args, "byollvm")
 155
 156         srcdir := llvmConfig("--src-root")
 157
 158         tmpgopath, err := ioutil.TempDir("", "gopath")
 159         if err != nil {
 160                 panic(err.Error())
 161         }
 162
 163         for _, p := range packages {
 164                 path := filepath.Join(tmpgopath, "src", p.pkgpath)
 165                 err := os.MkdirAll(filepath.Dir(path), os.ModePerm)
 166                 if err != nil {
 167                         panic(err.Error())
 168                 }
 169
 170                 abspath := p.llvmpath
 171                 if !filepath.IsAbs(abspath) {
 172                         abspath = filepath.Join(srcdir, abspath)
 173                 }
 174
 175                 err = os.Symlink(abspath, path)
 176                 if err != nil {
 177                         panic(err.Error())
 178                 }
 179         }
 180
 181         newpath := os.Getenv("PATH")
 182
 183         newgopathlist := []string{tmpgopath}
 184         newgopathlist = append(newgopathlist, filepath.SplitList(os.Getenv("GOPATH"))...)
 185         newgopath := strings.Join(newgopathlist, string(filepath.ListSeparator))
 186
 187         flags := llvmFlags()
 188
 189         newenv := []string{
 190                 "CC=" + cc,
 191                 "CXX=" + cxx,
 192                 "CGO_CPPFLAGS=" + flags.cpp + " " + cppflags,
 193                 "CGO_CXXFLAGS=" + flags.cxx + " " + cxxflags,
 194                 "CGO_LDFLAGS=" + flags.ld + " " + ldflags,
 195                 "GOPATH=" + newgopath,
 196                 "PATH=" + newpath,
 197         }
 198         if llgo != "" {
 199                 newenv = append(newenv, "GCCGO="+llgo)
 200         }
 201
 202         for _, v := range os.Environ() {
 203                 if !strings.HasPrefix(v, "CC=") &&
 204                         !strings.HasPrefix(v, "CXX=") &&
 205                         !strings.HasPrefix(v, "CGO_CPPFLAGS=") &&
 206                         !strings.HasPrefix(v, "CGO_CXXFLAGS=") &&
 207                         !strings.HasPrefix(v, "CGO_LDFLAGS=") &&
 208                         !strings.HasPrefix(v, "GCCGO=") &&
 209                         !strings.HasPrefix(v, "GOPATH=") &&
 210                         !strings.HasPrefix(v, "PATH=") {
 211                         newenv = append(newenv, v)
 212                 }
 213         }
 214
 215         gocmdpath, err := exec.LookPath(gocmd)
 216         if err != nil {
 217                 panic(err.Error())
 218         }
 219
 220         proc, err := os.StartProcess(gocmdpath, append([]string{gocmd}, args...),
 221                 &os.ProcAttr{
 222                         Env:   newenv,
 223                         Files: []*os.File{os.Stdin, os.Stdout, os.Stderr},
 224                 })
 225         if err != nil {
 226                 panic(err.Error())
 227         }
 228         ps, err := proc.Wait()
 229         if err != nil {
 230                 panic(err.Error())
 231         }
 232
 233         os.RemoveAll(tmpgopath)
 234
 235         if !ps.Success() {
 236                 os.Exit(1)
 237         }
 238 }
 239
 240 func usage() {
 241         fmt.Println(`Usage: llvm-go subcommand [flags]
 242
 243 Available subcommands: build get install run test print-components print-config`)
 244         os.Exit(0)
 245 }
 246
 247 func main() {
 248         cc := os.Getenv("CC")
 249         cxx := os.Getenv("CXX")
 250         cppflags := os.Getenv("CGO_CPPFLAGS")
 251         cxxflags := os.Getenv("CGO_CXXFLAGS")
 252         ldflags := os.Getenv("CGO_LDFLAGS")
 253         gocmd := "go"
 254         llgo := ""
 255         packagesString := ""
 256
 257         flags := []struct {
 258                 name string
 259                 dest *string
 260         }{
 261                 {"cc", &cc},
 262                 {"cxx", &cxx},
 263                 {"go", &gocmd},
 264                 {"llgo", &llgo},
 265                 {"cppflags", &cppflags},
 266                 {"ldflags", &ldflags},
 267                 {"packages", &packagesString},
 268         }
 269
 270         args := os.Args[1:]
 271 LOOP:
 272         for {
 273                 if len(args) == 0 {
 274                         usage()
 275                 }
 276                 for _, flag := range flags {
 277                         if strings.HasPrefix(args[0], flag.name+"=") {
 278                                 *flag.dest = args[0][len(flag.name)+1:]
 279                                 args = args[1:]
 280                                 continue LOOP
 281                         }
 282                 }
 283                 break
 284         }
 285
 286         packages := packages
 287         if packagesString != "" {
 288                 for _, field := range strings.Fields(packagesString) {
 289                         pos := strings.IndexRune(field, '=')
 290                         if pos == -1 {
 291                                 fmt.Fprintf(os.Stderr, "invalid packages value %q, expected 'pkgpath=llvmpath [pkgpath=llvmpath ...]'\n", packagesString)
 292                                 os.Exit(1)
 293                         }
 294                         packages = append(packages, pkg{
 295                                 pkgpath:  field[:pos],
 296                                 llvmpath: field[pos+1:],
 297                         })
 298                 }
 299         }
 300
 301         switch args[0] {
 302         case "build", "get", "install", "run", "test":
 303                 runGoWithLLVMEnv(args, cc, cxx, gocmd, llgo, cppflags, cxxflags, ldflags, packages)
 304         case "print-components":
 305                 printComponents()
 306         case "print-config":
 307                 printConfig()
 308         default:
 309                 usage()
 310         }
 311 }