github.com/flyinox/gosm@v0.0.0-20171117061539-16768cb62077/src/cmd/go/internal/envcmd/env.go (about)

     1  // Copyright 2012 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  // Package envcmd implements the ``go env'' command.
     6  package envcmd
     7  
     8  import (
     9  	"encoding/json"
    10  	"fmt"
    11  	"os"
    12  	"runtime"
    13  	"strings"
    14  
    15  	"cmd/go/internal/base"
    16  	"cmd/go/internal/cfg"
    17  	"cmd/go/internal/load"
    18  	"cmd/go/internal/work"
    19  )
    20  
    21  var CmdEnv = &base.Command{
    22  	UsageLine: "env [-json] [var ...]",
    23  	Short:     "print Go environment information",
    24  	Long: `
    25  Env prints Go environment information.
    26  
    27  By default env prints information as a shell script
    28  (on Windows, a batch file). If one or more variable
    29  names is given as arguments, env prints the value of
    30  each named variable on its own line.
    31  
    32  The -json flag prints the environment in JSON format
    33  instead of as a shell script.
    34  	`,
    35  }
    36  
    37  func init() {
    38  	CmdEnv.Run = runEnv // break init cycle
    39  }
    40  
    41  var envJson = CmdEnv.Flag.Bool("json", false, "")
    42  
    43  func MkEnv() []cfg.EnvVar {
    44  	var b work.Builder
    45  	b.Init()
    46  
    47  	env := []cfg.EnvVar{
    48  		{Name: "GOARCH", Value: cfg.Goarch},
    49  		{Name: "GOBIN", Value: cfg.GOBIN},
    50  		{Name: "GOEXE", Value: cfg.ExeSuffix},
    51  		{Name: "GOHOSTARCH", Value: runtime.GOARCH},
    52  		{Name: "GOHOSTOS", Value: runtime.GOOS},
    53  		{Name: "GOOS", Value: cfg.Goos},
    54  		{Name: "GOPATH", Value: cfg.BuildContext.GOPATH},
    55  		{Name: "GORACE", Value: os.Getenv("GORACE")},
    56  		{Name: "GOROOT", Value: cfg.GOROOT},
    57  		{Name: "GOTOOLDIR", Value: base.ToolDir},
    58  
    59  		// disable escape codes in clang errors
    60  		{Name: "TERM", Value: "dumb"},
    61  	}
    62  
    63  	if work.GccgoBin != "" {
    64  		env = append(env, cfg.EnvVar{Name: "GCCGO", Value: work.GccgoBin})
    65  	} else {
    66  		env = append(env, cfg.EnvVar{Name: "GCCGO", Value: work.GccgoName})
    67  	}
    68  
    69  	switch cfg.Goarch {
    70  	case "arm":
    71  		env = append(env, cfg.EnvVar{Name: "GOARM", Value: cfg.GOARM})
    72  	case "386":
    73  		env = append(env, cfg.EnvVar{Name: "GO386", Value: cfg.GO386})
    74  	}
    75  
    76  	cmd := b.GccCmd(".")
    77  	env = append(env, cfg.EnvVar{Name: "CC", Value: cmd[0]})
    78  	env = append(env, cfg.EnvVar{Name: "GOGCCFLAGS", Value: strings.Join(cmd[3:], " ")})
    79  	cmd = b.GxxCmd(".")
    80  	env = append(env, cfg.EnvVar{Name: "CXX", Value: cmd[0]})
    81  
    82  	if cfg.BuildContext.CgoEnabled {
    83  		env = append(env, cfg.EnvVar{Name: "CGO_ENABLED", Value: "1"})
    84  	} else {
    85  		env = append(env, cfg.EnvVar{Name: "CGO_ENABLED", Value: "0"})
    86  	}
    87  
    88  	return env
    89  }
    90  
    91  func findEnv(env []cfg.EnvVar, name string) string {
    92  	for _, e := range env {
    93  		if e.Name == name {
    94  			return e.Value
    95  		}
    96  	}
    97  	return ""
    98  }
    99  
   100  // ExtraEnvVars returns environment variables that should not leak into child processes.
   101  func ExtraEnvVars() []cfg.EnvVar {
   102  	var b work.Builder
   103  	b.Init()
   104  	cppflags, cflags, cxxflags, fflags, ldflags := b.CFlags(&load.Package{})
   105  	return []cfg.EnvVar{
   106  		{Name: "CGO_CFLAGS", Value: strings.Join(cflags, " ")},
   107  		{Name: "CGO_CPPFLAGS", Value: strings.Join(cppflags, " ")},
   108  		{Name: "CGO_CXXFLAGS", Value: strings.Join(cxxflags, " ")},
   109  		{Name: "CGO_FFLAGS", Value: strings.Join(fflags, " ")},
   110  		{Name: "CGO_LDFLAGS", Value: strings.Join(ldflags, " ")},
   111  		{Name: "PKG_CONFIG", Value: b.PkgconfigCmd()},
   112  	}
   113  }
   114  
   115  func runEnv(cmd *base.Command, args []string) {
   116  	env := cfg.CmdEnv
   117  	env = append(env, ExtraEnvVars()...)
   118  	if len(args) > 0 {
   119  		if *envJson {
   120  			var es []cfg.EnvVar
   121  			for _, name := range args {
   122  				e := cfg.EnvVar{Name: name, Value: findEnv(env, name)}
   123  				es = append(es, e)
   124  			}
   125  			printEnvAsJSON(es)
   126  		} else {
   127  			for _, name := range args {
   128  				fmt.Printf("%s\n", findEnv(env, name))
   129  			}
   130  		}
   131  		return
   132  	}
   133  
   134  	if *envJson {
   135  		printEnvAsJSON(env)
   136  		return
   137  	}
   138  
   139  	for _, e := range env {
   140  		if e.Name != "TERM" {
   141  			switch runtime.GOOS {
   142  			default:
   143  				fmt.Printf("%s=\"%s\"\n", e.Name, e.Value)
   144  			case "plan9":
   145  				if strings.IndexByte(e.Value, '\x00') < 0 {
   146  					fmt.Printf("%s='%s'\n", e.Name, strings.Replace(e.Value, "'", "''", -1))
   147  				} else {
   148  					v := strings.Split(e.Value, "\x00")
   149  					fmt.Printf("%s=(", e.Name)
   150  					for x, s := range v {
   151  						if x > 0 {
   152  							fmt.Printf(" ")
   153  						}
   154  						fmt.Printf("%s", s)
   155  					}
   156  					fmt.Printf(")\n")
   157  				}
   158  			case "windows":
   159  				fmt.Printf("set %s=%s\n", e.Name, e.Value)
   160  			}
   161  		}
   162  	}
   163  }
   164  
   165  func printEnvAsJSON(env []cfg.EnvVar) {
   166  	m := make(map[string]string)
   167  	for _, e := range env {
   168  		if e.Name == "TERM" {
   169  			continue
   170  		}
   171  		m[e.Name] = e.Value
   172  	}
   173  	enc := json.NewEncoder(os.Stdout)
   174  	enc.SetIndent("", "\t")
   175  	if err := enc.Encode(m); err != nil {
   176  		base.Fatalf("%s", err)
   177  	}
   178  }