github.com/goproxy0/go@v0.0.0-20171111080102-49cc0c489d2c/src/cmd/link/internal/ld/ld.go (about)

     1  // Derived from Inferno utils/6l/obj.c and utils/6l/span.c
     2  // https://bitbucket.org/inferno-os/inferno-os/src/default/utils/6l/obj.c
     3  // https://bitbucket.org/inferno-os/inferno-os/src/default/utils/6l/span.c
     4  //
     5  //	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
     6  //	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
     7  //	Portions Copyright © 1997-1999 Vita Nuova Limited
     8  //	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
     9  //	Portions Copyright © 2004,2006 Bruce Ellis
    10  //	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
    11  //	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
    12  //	Portions Copyright © 2009 The Go Authors. All rights reserved.
    13  //
    14  // Permission is hereby granted, free of charge, to any person obtaining a copy
    15  // of this software and associated documentation files (the "Software"), to deal
    16  // in the Software without restriction, including without limitation the rights
    17  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    18  // copies of the Software, and to permit persons to whom the Software is
    19  // furnished to do so, subject to the following conditions:
    20  //
    21  // The above copyright notice and this permission notice shall be included in
    22  // all copies or substantial portions of the Software.
    23  //
    24  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    25  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    26  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
    27  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    28  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    29  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    30  // THE SOFTWARE.
    31  
    32  package ld
    33  
    34  import (
    35  	"cmd/link/internal/sym"
    36  	"io/ioutil"
    37  	"log"
    38  	"os"
    39  	"path"
    40  	"path/filepath"
    41  	"strconv"
    42  	"strings"
    43  )
    44  
    45  func (ctxt *Link) readImportCfg(file string) {
    46  	ctxt.PackageFile = make(map[string]string)
    47  	ctxt.PackageShlib = make(map[string]string)
    48  	data, err := ioutil.ReadFile(file)
    49  	if err != nil {
    50  		log.Fatalf("-importcfg: %v", err)
    51  	}
    52  
    53  	for lineNum, line := range strings.Split(string(data), "\n") {
    54  		lineNum++ // 1-based
    55  		line = strings.TrimSpace(line)
    56  		if line == "" {
    57  			continue
    58  		}
    59  		if line == "" || strings.HasPrefix(line, "#") {
    60  			continue
    61  		}
    62  
    63  		var verb, args string
    64  		if i := strings.Index(line, " "); i < 0 {
    65  			verb = line
    66  		} else {
    67  			verb, args = line[:i], strings.TrimSpace(line[i+1:])
    68  		}
    69  		var before, after string
    70  		if i := strings.Index(args, "="); i >= 0 {
    71  			before, after = args[:i], args[i+1:]
    72  		}
    73  		switch verb {
    74  		default:
    75  			log.Fatalf("%s:%d: unknown directive %q", file, lineNum, verb)
    76  		case "packagefile":
    77  			if before == "" || after == "" {
    78  				log.Fatalf(`%s:%d: invalid packagefile: syntax is "packagefile path=filename"`, file, lineNum)
    79  			}
    80  			ctxt.PackageFile[before] = after
    81  		case "packageshlib":
    82  			if before == "" || after == "" {
    83  				log.Fatalf(`%s:%d: invalid packageshlib: syntax is "packageshlib path=filename"`, file, lineNum)
    84  			}
    85  			ctxt.PackageShlib[before] = after
    86  		}
    87  	}
    88  }
    89  
    90  func pkgname(lib string) string {
    91  	name := path.Clean(lib)
    92  	// runtime.a -> runtime, runtime.6 -> runtime
    93  	pkg := name
    94  	if len(pkg) >= 2 && pkg[len(pkg)-2] == '.' {
    95  		pkg = pkg[:len(pkg)-2]
    96  	}
    97  	return pkg
    98  }
    99  
   100  func findlib(ctxt *Link, lib string) (string, bool) {
   101  	name := path.Clean(lib)
   102  
   103  	var pname string
   104  	isshlib := false
   105  
   106  	if ctxt.linkShared && ctxt.PackageShlib[name] != "" {
   107  		pname = ctxt.PackageShlib[name]
   108  		isshlib = true
   109  	} else if ctxt.PackageFile != nil {
   110  		pname = ctxt.PackageFile[name]
   111  		if pname == "" {
   112  			ctxt.Logf("cannot find package %s (using -importcfg)\n", name)
   113  			return "", false
   114  		}
   115  	} else {
   116  		if filepath.IsAbs(name) {
   117  			pname = name
   118  		} else {
   119  			pkg := pkgname(lib)
   120  			// Add .a if needed; the new -importcfg modes
   121  			// do not put .a into the package name anymore.
   122  			// This only matters when people try to mix
   123  			// compiles using -importcfg with links not using -importcfg,
   124  			// such as when running quick things like
   125  			// 'go tool compile x.go && go tool link x.o'
   126  			// by hand against a standard library built using -importcfg.
   127  			if !strings.HasSuffix(name, ".a") && !strings.HasSuffix(name, ".o") {
   128  				name += ".a"
   129  			}
   130  			// try dot, -L "libdir", and then goroot.
   131  			for _, dir := range ctxt.Libdir {
   132  				if ctxt.linkShared {
   133  					pname = dir + "/" + pkg + ".shlibname"
   134  					if _, err := os.Stat(pname); err == nil {
   135  						isshlib = true
   136  						break
   137  					}
   138  				}
   139  				pname = dir + "/" + name
   140  				if _, err := os.Stat(pname); err == nil {
   141  					break
   142  				}
   143  			}
   144  		}
   145  		pname = path.Clean(pname)
   146  	}
   147  
   148  	return pname, isshlib
   149  }
   150  
   151  func addlib(ctxt *Link, src string, obj string, lib string) *sym.Library {
   152  	pkg := pkgname(lib)
   153  
   154  	// already loaded?
   155  	if l := ctxt.LibraryByPkg[pkg]; l != nil {
   156  		return l
   157  	}
   158  
   159  	pname, isshlib := findlib(ctxt, lib)
   160  
   161  	if ctxt.Debugvlog > 1 {
   162  		ctxt.Logf("%5.2f addlib: %s %s pulls in %s isshlib %v\n", elapsed(), obj, src, pname, isshlib)
   163  	}
   164  
   165  	if isshlib {
   166  		return addlibpath(ctxt, src, obj, "", pkg, pname)
   167  	}
   168  	return addlibpath(ctxt, src, obj, pname, pkg, "")
   169  }
   170  
   171  /*
   172   * add library to library list, return added library.
   173   *	srcref: src file referring to package
   174   *	objref: object file referring to package
   175   *	file: object file, e.g., /home/rsc/go/pkg/container/vector.a
   176   *	pkg: package import path, e.g. container/vector
   177   *	shlib: path to shared library, or .shlibname file holding path
   178   */
   179  func addlibpath(ctxt *Link, srcref string, objref string, file string, pkg string, shlib string) *sym.Library {
   180  	if l := ctxt.LibraryByPkg[pkg]; l != nil {
   181  		return l
   182  	}
   183  
   184  	if ctxt.Debugvlog > 1 {
   185  		ctxt.Logf("%5.2f addlibpath: srcref: %s objref: %s file: %s pkg: %s shlib: %s\n", Cputime(), srcref, objref, file, pkg, shlib)
   186  	}
   187  
   188  	l := &sym.Library{}
   189  	ctxt.LibraryByPkg[pkg] = l
   190  	ctxt.Library = append(ctxt.Library, l)
   191  	l.Objref = objref
   192  	l.Srcref = srcref
   193  	l.File = file
   194  	l.Pkg = pkg
   195  	if shlib != "" {
   196  		if strings.HasSuffix(shlib, ".shlibname") {
   197  			data, err := ioutil.ReadFile(shlib)
   198  			if err != nil {
   199  				Errorf(nil, "cannot read %s: %v", shlib, err)
   200  			}
   201  			shlib = strings.TrimSpace(string(data))
   202  		}
   203  		l.Shlib = shlib
   204  	}
   205  	return l
   206  }
   207  
   208  func atolwhex(s string) int64 {
   209  	n, _ := strconv.ParseInt(s, 0, 64)
   210  	return n
   211  }