cgo_pkgconfig.go raw

   1  // Copyright 2013 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 cgo
   6  
   7  import (
   8  	"errors"
   9  	"fmt"
  10  	"go/build"
  11  	"os/exec"
  12  	"strings"
  13  )
  14  
  15  // pkgConfig runs pkg-config with the specified arguments and returns the flags it prints.
  16  func pkgConfig(mode string, pkgs []string) (flags []string, err error) {
  17  	cmd := exec.Command("pkg-config", append([]string{mode}, pkgs...)...)
  18  	out, err := cmd.Output()
  19  	if err != nil {
  20  		s := fmt.Sprintf("%s failed: %v", strings.Join(cmd.Args, " "), err)
  21  		if len(out) > 0 {
  22  			s = fmt.Sprintf("%s: %s", s, out)
  23  		}
  24  		if err, ok := err.(*exec.ExitError); ok && len(err.Stderr) > 0 {
  25  			s = fmt.Sprintf("%s\nstderr:\n%s", s, err.Stderr)
  26  		}
  27  		return nil, errors.New(s)
  28  	}
  29  	if len(out) > 0 {
  30  		flags = strings.Fields(string(out))
  31  	}
  32  	return
  33  }
  34  
  35  // pkgConfigFlags calls pkg-config if needed and returns the cflags
  36  // needed to build the package.
  37  func pkgConfigFlags(p *build.Package) (cflags []string, err error) {
  38  	if len(p.CgoPkgConfig) == 0 {
  39  		return nil, nil
  40  	}
  41  	return pkgConfig("--cflags", p.CgoPkgConfig)
  42  }
  43