util.go

Documentation: cmd/cgo

     1  // Copyright 2009 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 main
     6  
     7  import (
     8  	"bytes"
     9  	"fmt"
    10  	"go/token"
    11  	"os"
    12  	"os/exec"
    13  )
    14  
    15  // run runs the command argv, feeding in stdin on standard input.
    16  // It returns the output to standard output and standard error.
    17  // ok indicates whether the command exited successfully.
    18  func run(stdin []byte, argv []string) (stdout, stderr []byte, ok bool) {
    19  	if i := find(argv, "-xc"); i >= 0 && argv[len(argv)-1] == "-" {
    20  		// Some compilers have trouble with standard input.
    21  		// Others have trouble with -xc.
    22  		// Avoid both problems by writing a file with a .c extension.
    23  		f, err := os.CreateTemp("", "cgo-gcc-input-")
    24  		if err != nil {
    25  			fatalf("%s", err)
    26  		}
    27  		name := f.Name()
    28  		f.Close()
    29  		if err := os.WriteFile(name+".c", stdin, 0666); err != nil {
    30  			os.Remove(name)
    31  			fatalf("%s", err)
    32  		}
    33  		defer os.Remove(name)
    34  		defer os.Remove(name + ".c")
    35  
    36  		// Build new argument list without -xc and trailing -.
    37  		new := append(argv[:i:i], argv[i+1:len(argv)-1]...)
    38  
    39  		// Since we are going to write the file to a temporary directory,
    40  		// we will need to add -I . explicitly to the command line:
    41  		// any #include "foo" before would have looked in the current
    42  		// directory as the directory "holding" standard input, but now
    43  		// the temporary directory holds the input.
    44  		// We've also run into compilers that reject "-I." but allow "-I", ".",
    45  		// so be sure to use two arguments.
    46  		// This matters mainly for people invoking cgo -godefs by hand.
    47  		new = append(new, "-I", ".")
    48  
    49  		// Finish argument list with path to C file.
    50  		new = append(new, name+".c")
    51  
    52  		argv = new
    53  		stdin = nil
    54  	}
    55  
    56  	p := exec.Command(argv[0], argv[1:]...)
    57  	p.Stdin = bytes.NewReader(stdin)
    58  	var bout, berr bytes.Buffer
    59  	p.Stdout = &bout
    60  	p.Stderr = &berr
    61  	// Disable escape codes in clang error messages.
    62  	p.Env = append(os.Environ(), "TERM=dumb")
    63  	err := p.Run()
    64  	if _, ok := err.(*exec.ExitError); err != nil && !ok {
    65  		fatalf("exec %s: %s", argv[0], err)
    66  	}
    67  	ok = p.ProcessState.Success()
    68  	stdout, stderr = bout.Bytes(), berr.Bytes()
    69  	return
    70  }
    71  
    72  func find(argv []string, target string) int {
    73  	for i, arg := range argv {
    74  		if arg == target {
    75  			return i
    76  		}
    77  	}
    78  	return -1
    79  }
    80  
    81  func lineno(pos token.Pos) string {
    82  	return fset.Position(pos).String()
    83  }
    84  
    85  // Die with an error message.
    86  func fatalf(msg string, args ...interface{}) {
    87  	// If we've already printed other errors, they might have
    88  	// caused the fatal condition. Assume they're enough.
    89  	if nerrors == 0 {
    90  		fmt.Fprintf(os.Stderr, "cgo: "+msg+"\n", args...)
    91  	}
    92  	os.Exit(2)
    93  }
    94  
    95  var nerrors int
    96  
    97  func error_(pos token.Pos, msg string, args ...interface{}) {
    98  	nerrors++
    99  	if pos.IsValid() {
   100  		fmt.Fprintf(os.Stderr, "%s: ", fset.Position(pos).String())
   101  	} else {
   102  		fmt.Fprintf(os.Stderr, "cgo: ")
   103  	}
   104  	fmt.Fprintf(os.Stderr, msg, args...)
   105  	fmt.Fprintf(os.Stderr, "\n")
   106  }
   107  
   108  func creat(name string) *os.File {
   109  	f, err := os.Create(name)
   110  	if err != nil {
   111  		fatalf("%s", err)
   112  	}
   113  	return f
   114  }
   115
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