github.com/zxy12/go_duplicate_112_new@v0.0.0-20200807091221-747231827200/src/cmd/go/internal/run/run.go (about)

     1  // Copyright 2011 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 run implements the ``go run'' command.
     6  package run
     7  
     8  import (
     9  	"fmt"
    10  	"os"
    11  	"strings"
    12  
    13  	"cmd/go/internal/base"
    14  	"cmd/go/internal/cfg"
    15  	"cmd/go/internal/load"
    16  	"cmd/go/internal/str"
    17  	"cmd/go/internal/work"
    18  )
    19  
    20  var CmdRun = &base.Command{
    21  	UsageLine: "go run [build flags] [-exec xprog] package [arguments...]",
    22  	Short:     "compile and run Go program",
    23  	Long: `
    24  Run compiles and runs the named main Go package.
    25  Typically the package is specified as a list of .go source files,
    26  but it may also be an import path, file system path, or pattern
    27  matching a single known package, as in 'go run .' or 'go run my/cmd'.
    28  
    29  By default, 'go run' runs the compiled binary directly: 'a.out arguments...'.
    30  If the -exec flag is given, 'go run' invokes the binary using xprog:
    31  	'xprog a.out arguments...'.
    32  If the -exec flag is not given, GOOS or GOARCH is different from the system
    33  default, and a program named go_$GOOS_$GOARCH_exec can be found
    34  on the current search path, 'go run' invokes the binary using that program,
    35  for example 'go_nacl_386_exec a.out arguments...'. This allows execution of
    36  cross-compiled programs when a simulator or other execution method is
    37  available.
    38  
    39  The exit status of Run is not the exit status of the compiled binary.
    40  
    41  For more about build flags, see 'go help build'.
    42  For more about specifying packages, see 'go help packages'.
    43  
    44  See also: go build.
    45  	`,
    46  }
    47  
    48  func init() {
    49  	CmdRun.Run = runRun // break init loop
    50  
    51  	work.AddBuildFlags(CmdRun)
    52  	CmdRun.Flag.Var((*base.StringsFlag)(&work.ExecCmd), "exec", "")
    53  }
    54  
    55  func printStderr(args ...interface{}) (int, error) {
    56  	return fmt.Fprint(os.Stderr, args...)
    57  }
    58  
    59  func runRun(cmd *base.Command, args []string) {
    60  	work.BuildInit()
    61  	var b work.Builder
    62  	b.Init()
    63  	b.Print = printStderr
    64  	i := 0
    65  	for i < len(args) && strings.HasSuffix(args[i], ".go") {
    66  		i++
    67  	}
    68  	var p *load.Package
    69  	if i > 0 {
    70  		files := args[:i]
    71  		for _, file := range files {
    72  			if strings.HasSuffix(file, "_test.go") {
    73  				// GoFilesPackage is going to assign this to TestGoFiles.
    74  				// Reject since it won't be part of the build.
    75  				base.Fatalf("go run: cannot run *_test.go files (%s)", file)
    76  			}
    77  		}
    78  		p = load.GoFilesPackage(files)
    79  	} else if len(args) > 0 && !strings.HasPrefix(args[0], "-") {
    80  		pkgs := load.PackagesAndErrors(args[:1])
    81  		if len(pkgs) == 0 {
    82  			base.Fatalf("go run: no packages loaded from %s", args[0])
    83  		}
    84  		if len(pkgs) > 1 {
    85  			var names []string
    86  			for _, p := range pkgs {
    87  				names = append(names, p.ImportPath)
    88  			}
    89  			base.Fatalf("go run: pattern %s matches multiple packages:\n\t%s", args[0], strings.Join(names, "\n\t"))
    90  		}
    91  		p = pkgs[0]
    92  		i++
    93  	} else {
    94  		base.Fatalf("go run: no go files listed")
    95  	}
    96  	cmdArgs := args[i:]
    97  
    98  	if p.Error != nil {
    99  		base.Fatalf("%s", p.Error)
   100  	}
   101  	p.Internal.OmitDebug = true
   102  	if len(p.DepsErrors) > 0 {
   103  		// Since these are errors in dependencies,
   104  		// the same error might show up multiple times,
   105  		// once in each package that depends on it.
   106  		// Only print each once.
   107  		printed := map[*load.PackageError]bool{}
   108  		for _, err := range p.DepsErrors {
   109  			if !printed[err] {
   110  				printed[err] = true
   111  				base.Errorf("%s", err)
   112  			}
   113  		}
   114  	}
   115  	base.ExitIfErrors()
   116  	if p.Name != "main" {
   117  		base.Fatalf("go run: cannot run non-main package")
   118  	}
   119  	p.Target = "" // must build - not up to date
   120  	var src string
   121  	if len(p.GoFiles) > 0 {
   122  		src = p.GoFiles[0]
   123  	} else if len(p.CgoFiles) > 0 {
   124  		src = p.CgoFiles[0]
   125  	} else {
   126  		// this case could only happen if the provided source uses cgo
   127  		// while cgo is disabled.
   128  		hint := ""
   129  		if !cfg.BuildContext.CgoEnabled {
   130  			hint = " (cgo is disabled)"
   131  		}
   132  		base.Fatalf("go run: no suitable source files%s", hint)
   133  	}
   134  	p.Internal.ExeName = src[:len(src)-len(".go")] // name temporary executable for first go file
   135  	a1 := b.LinkAction(work.ModeBuild, work.ModeBuild, p)
   136  	a := &work.Action{Mode: "go run", Func: buildRunProgram, Args: cmdArgs, Deps: []*work.Action{a1}}
   137  	b.Do(a)
   138  }
   139  
   140  // buildRunProgram is the action for running a binary that has already
   141  // been compiled. We ignore exit status.
   142  func buildRunProgram(b *work.Builder, a *work.Action) error {
   143  	cmdline := str.StringList(work.FindExecCmd(), a.Deps[0].Target, a.Args)
   144  	if cfg.BuildN || cfg.BuildX {
   145  		b.Showcmd("", "%s", strings.Join(cmdline, " "))
   146  		if cfg.BuildN {
   147  			return nil
   148  		}
   149  	}
   150  
   151  	base.RunStdin(cmdline)
   152  	return nil
   153  }