Source file src/cmd/internal/objabi/line.go

Documentation: cmd/internal/objabi

  // Copyright 2009 The Go Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style
  // license that can be found in the LICENSE file.
  
  package objabi
  
  import (
  	"os"
  	"path/filepath"
  )
  
  // WorkingDir returns the current working directory
  // (or "/???" if the directory cannot be identified),
  // with "/" as separator.
  func WorkingDir() string {
  	var path string
  	path, _ = os.Getwd()
  	if path == "" {
  		path = "/???"
  	}
  	return filepath.ToSlash(path)
  }
  
  // AbsFile returns the absolute filename for file in the given directory.
  // It also removes a leading pathPrefix, or else rewrites a leading $GOROOT
  // prefix to the literal "$GOROOT".
  // If the resulting path is the empty string, the result is "??".
  func AbsFile(dir, file, pathPrefix string) string {
  	abs := file
  	if dir != "" && !filepath.IsAbs(file) {
  		abs = filepath.Join(dir, file)
  	}
  
  	if pathPrefix != "" && hasPathPrefix(abs, pathPrefix) {
  		if abs == pathPrefix {
  			abs = ""
  		} else {
  			abs = abs[len(pathPrefix)+1:]
  		}
  	} else if hasPathPrefix(abs, GOROOT) {
  		abs = "$GOROOT" + abs[len(GOROOT):]
  	}
  	if abs == "" {
  		abs = "??"
  	}
  
  	return abs
  }
  
  // Does s have t as a path prefix?
  // That is, does s == t or does s begin with t followed by a slash?
  // For portability, we allow ASCII case folding, so that hasPathPrefix("a/b/c", "A/B") is true.
  // Similarly, we allow slash folding, so that hasPathPrefix("a/b/c", "a\\b") is true.
  // We do not allow full Unicode case folding, for fear of causing more confusion
  // or harm than good. (For an example of the kinds of things that can go wrong,
  // see http://article.gmane.org/gmane.linux.kernel/1853266.)
  func hasPathPrefix(s string, t string) bool {
  	if len(t) > len(s) {
  		return false
  	}
  	var i int
  	for i = 0; i < len(t); i++ {
  		cs := int(s[i])
  		ct := int(t[i])
  		if 'A' <= cs && cs <= 'Z' {
  			cs += 'a' - 'A'
  		}
  		if 'A' <= ct && ct <= 'Z' {
  			ct += 'a' - 'A'
  		}
  		if cs == '\\' {
  			cs = '/'
  		}
  		if ct == '\\' {
  			ct = '/'
  		}
  		if cs != ct {
  			return false
  		}
  	}
  	return i >= len(s) || s[i] == '/' || s[i] == '\\'
  }
  

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