src/cmd/link/internal/ld/ld.go - go - Git at Google

 // Derived from Inferno utils/6l/obj.c and utils/6l/span.c
 // https://bitbucket.org/inferno-os/inferno-os/src/default/utils/6l/obj.c
 // https://bitbucket.org/inferno-os/inferno-os/src/default/utils/6l/span.c
 //
 //	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
 //	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
 //	Portions Copyright © 1997-1999 Vita Nuova Limited
 //	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
 //	Portions Copyright © 2004,2006 Bruce Ellis
 //	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
 //	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
 //	Portions Copyright © 2009 The Go Authors. All rights reserved.
 //
 // Permission is hereby granted, free of charge, to any person obtaining a copy
 // of this software and associated documentation files (the "Software"), to deal
 // in the Software without restriction, including without limitation the rights
 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 // copies of the Software, and to permit persons to whom the Software is
 // furnished to do so, subject to the following conditions:
 //
 // The above copyright notice and this permission notice shall be included in
 // all copies or substantial portions of the Software.
 //
 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.

 package ld

 import (
 	"cmd/internal/goobj2"
 	"cmd/link/internal/loader"
 	"cmd/link/internal/sym"
 	"io/ioutil"
 	"log"
 	"os"
 	"path"
 	"path/filepath"
 	"strconv"
 	"strings"
 )

 func (ctxt *Link) readImportCfg(file string) {
 	ctxt.PackageFile = make(map[string]string)
 	ctxt.PackageShlib = make(map[string]string)
 	data, err := ioutil.ReadFile(file)
 	if err != nil {
 		log.Fatalf("-importcfg: %v", err)
 	}

 	for lineNum, line := range strings.Split(string(data), "\n") {
 		lineNum++ // 1-based
 		line = strings.TrimSpace(line)
 		if line == "" {
 			continue
 		}
 		if line == "" || strings.HasPrefix(line, "#") {
 			continue
 		}

 		var verb, args string
 		if i := strings.Index(line, " "); i < 0 {
 			verb = line
 		} else {
 			verb, args = line[:i], strings.TrimSpace(line[i+1:])
 		}
 		var before, after string
 		if i := strings.Index(args, "="); i >= 0 {
 			before, after = args[:i], args[i+1:]
 		}
 		switch verb {
 		default:
 			log.Fatalf("%s:%d: unknown directive %q", file, lineNum, verb)
 		case "packagefile":
 			if before == "" || after == "" {
 				log.Fatalf(`%s:%d: invalid packagefile: syntax is "packagefile path=filename"`, file, lineNum)
 			}
 			ctxt.PackageFile[before] = after
 		case "packageshlib":
 			if before == "" || after == "" {
 				log.Fatalf(`%s:%d: invalid packageshlib: syntax is "packageshlib path=filename"`, file, lineNum)
 			}
 			ctxt.PackageShlib[before] = after
 		}
 	}
 }

 func pkgname(ctxt *Link, lib string) string {
 	name := path.Clean(lib)

 	// When using importcfg, we have the final package name.
 	if ctxt.PackageFile != nil {
 		return name
 	}

 	// runtime.a -> runtime, runtime.6 -> runtime
 	pkg := name
 	if len(pkg) >= 2 && pkg[len(pkg)-2] == '.' {
 		pkg = pkg[:len(pkg)-2]
 	}
 	return pkg
 }

 func findlib(ctxt *Link, lib string) (string, bool) {
 	name := path.Clean(lib)

 	var pname string
 	isshlib := false

 	if ctxt.linkShared && ctxt.PackageShlib[name] != "" {
 		pname = ctxt.PackageShlib[name]
 		isshlib = true
 	} else if ctxt.PackageFile != nil {
 		pname = ctxt.PackageFile[name]
 		if pname == "" {
 			ctxt.Logf("cannot find package %s (using -importcfg)\n", name)
 			return "", false
 		}
 	} else {
 		if filepath.IsAbs(name) {
 			pname = name
 		} else {
 			pkg := pkgname(ctxt, lib)
 			// Add .a if needed; the new -importcfg modes
 			// do not put .a into the package name anymore.
 			// This only matters when people try to mix
 			// compiles using -importcfg with links not using -importcfg,
 			// such as when running quick things like
 			// 'go tool compile x.go && go tool link x.o'
 			// by hand against a standard library built using -importcfg.
 			if !strings.HasSuffix(name, ".a") && !strings.HasSuffix(name, ".o") {
 				name += ".a"
 			}
 			// try dot, -L "libdir", and then goroot.
 			for _, dir := range ctxt.Libdir {
 				if ctxt.linkShared {
 					pname = filepath.Join(dir, pkg+".shlibname")
 					if _, err := os.Stat(pname); err == nil {
 						isshlib = true
 						break
 					}
 				}
 				pname = filepath.Join(dir, name)
 				if _, err := os.Stat(pname); err == nil {
 					break
 				}
 			}
 		}
 		pname = filepath.Clean(pname)
 	}

 	return pname, isshlib
 }

 func addlib(ctxt *Link, src, obj, lib string, fingerprint goobj2.FingerprintType) *sym.Library {
 	pkg := pkgname(ctxt, lib)

 	// already loaded?
 	if l := ctxt.LibraryByPkg[pkg]; l != nil {
 		checkFingerprint(l, l.Fingerprint, src, fingerprint)
 		return l
 	}

 	pname, isshlib := findlib(ctxt, lib)

 	if ctxt.Debugvlog > 1 {
 		ctxt.Logf("addlib: %s %s pulls in %s isshlib %v\n", obj, src, pname, isshlib)
 	}

 	if isshlib {
 		return addlibpath(ctxt, src, obj, "", pkg, pname, fingerprint)
 	}
 	return addlibpath(ctxt, src, obj, pname, pkg, "", fingerprint)
 }

 /*
  * add library to library list, return added library.
  *	srcref: src file referring to package
  *	objref: object file referring to package
  *	file: object file, e.g., /home/rsc/go/pkg/container/vector.a
  *	pkg: package import path, e.g. container/vector
  *	shlib: path to shared library, or .shlibname file holding path
  *	fingerprint: if not 0, expected fingerprint for import from srcref
  *	             fingerprint is 0 if the library is not imported (e.g. main)
  */
 func addlibpath(ctxt *Link, srcref, objref, file, pkg, shlib string, fingerprint goobj2.FingerprintType) *sym.Library {
 	if l := ctxt.LibraryByPkg[pkg]; l != nil {
 		return l
 	}

 	if ctxt.Debugvlog > 1 {
 		ctxt.Logf("addlibpath: srcref: %s objref: %s file: %s pkg: %s shlib: %s fingerprint: %x\n", srcref, objref, file, pkg, shlib, fingerprint)
 	}

 	l := &sym.Library{}
 	ctxt.LibraryByPkg[pkg] = l
 	ctxt.Library = append(ctxt.Library, l)
 	l.Objref = objref
 	l.Srcref = srcref
 	l.File = file
 	l.Pkg = pkg
 	l.Fingerprint = fingerprint
 	if shlib != "" {
 		if strings.HasSuffix(shlib, ".shlibname") {
 			data, err := ioutil.ReadFile(shlib)
 			if err != nil {
 				Errorf(nil, "cannot read %s: %v", shlib, err)
 			}
 			shlib = strings.TrimSpace(string(data))
 		}
 		l.Shlib = shlib
 	}
 	return l
 }

 func atolwhex(s string) int64 {
 	n, _ := strconv.ParseInt(s, 0, 64)
 	return n
 }

 // PrepareAddmoduledata returns a symbol builder that target-specific
 // code can use to build up the linker-generated go.link.addmoduledata
 // function, along with the sym for runtime.addmoduledata itself. If
 // this function is not needed (for example in cases where we're
 // linking a module that contains the runtime) the returned builder
 // will be nil.
 func PrepareAddmoduledata(ctxt *Link) (*loader.SymbolBuilder, loader.Sym) {
 	if !ctxt.DynlinkingGo() {
 		return nil, 0
 	}
 	amd := ctxt.loader.LookupOrCreateSym("runtime.addmoduledata", 0)
 	if ctxt.loader.SymType(amd) == sym.STEXT && ctxt.BuildMode != BuildModePlugin {
 		// we're linking a module containing the runtime -> no need for
 		// an init function
 		return nil, 0
 	}
 	ctxt.loader.SetAttrReachable(amd, true)

 	// Create a new init func text symbol. Caller will populate this
 	// sym with arch-specific content.
 	ifs := ctxt.loader.LookupOrCreateSym("go.link.addmoduledata", 0)
 	initfunc := ctxt.loader.MakeSymbolUpdater(ifs)
 	ctxt.loader.SetAttrReachable(ifs, true)
 	ctxt.loader.SetAttrLocal(ifs, true)
 	initfunc.SetType(sym.STEXT)

 	// Add the init func and/or addmoduledata to Textp2.
 	if ctxt.BuildMode == BuildModePlugin {
 		ctxt.Textp2 = append(ctxt.Textp2, amd)
 	}
 	ctxt.Textp2 = append(ctxt.Textp2, initfunc.Sym())

 	// Create an init array entry
 	amdi := ctxt.loader.LookupOrCreateSym("go.link.addmoduledatainit", 0)
 	initarray_entry := ctxt.loader.MakeSymbolUpdater(amdi)
 	ctxt.loader.SetAttrReachable(amdi, true)
 	ctxt.loader.SetAttrLocal(amdi, true)
 	initarray_entry.SetType(sym.SINITARR)
 	initarray_entry.AddAddr(ctxt.Arch, ifs)

 	return initfunc, amd
 }
	// Derived from Inferno utils/6l/obj.c and utils/6l/span.c
	// https://bitbucket.org/inferno-os/inferno-os/src/default/utils/6l/obj.c
	// https://bitbucket.org/inferno-os/inferno-os/src/default/utils/6l/span.c
	//
	// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
	// Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
	// Portions Copyright © 1997-1999 Vita Nuova Limited
	// Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
	// Portions Copyright © 2004,2006 Bruce Ellis
	// Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
	// Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
	// Portions Copyright © 2009 The Go Authors. All rights reserved.
	//
	// Permission is hereby granted, free of charge, to any person obtaining a copy
	// of this software and associated documentation files (the "Software"), to deal
	// in the Software without restriction, including without limitation the rights
	// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	// copies of the Software, and to permit persons to whom the Software is
	// furnished to do so, subject to the following conditions:
	//
	// The above copyright notice and this permission notice shall be included in
	// all copies or substantial portions of the Software.
	//
	// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	// THE SOFTWARE.

	package ld

	import (
	"cmd/internal/goobj2"
	"cmd/link/internal/loader"
	"cmd/link/internal/sym"
	"io/ioutil"
	"log"
	"os"
	"path"
	"path/filepath"
	"strconv"
	"strings"
	)

	func (ctxt *Link) readImportCfg(file string) {
	ctxt.PackageFile = make(map[string]string)
	ctxt.PackageShlib = make(map[string]string)
	data, err := ioutil.ReadFile(file)
	if err != nil {
	log.Fatalf("-importcfg: %v", err)
	}

	for lineNum, line := range strings.Split(string(data), "\n") {
	lineNum++ // 1-based
	line = strings.TrimSpace(line)
	if line == "" {
	continue
	}
	if line == "" \|\| strings.HasPrefix(line, "#") {
	continue
	}

	var verb, args string
	if i := strings.Index(line, " "); i < 0 {
	verb = line
	} else {
	verb, args = line[:i], strings.TrimSpace(line[i+1:])
	}
	var before, after string
	if i := strings.Index(args, "="); i >= 0 {
	before, after = args[:i], args[i+1:]
	}
	switch verb {
	default:
	log.Fatalf("%s:%d: unknown directive %q", file, lineNum, verb)
	case "packagefile":
	if before == "" \|\| after == "" {
	log.Fatalf(`%s:%d: invalid packagefile: syntax is "packagefile path=filename"`, file, lineNum)
	}
	ctxt.PackageFile[before] = after
	case "packageshlib":
	if before == "" \|\| after == "" {
	log.Fatalf(`%s:%d: invalid packageshlib: syntax is "packageshlib path=filename"`, file, lineNum)
	}
	ctxt.PackageShlib[before] = after
	}
	}
	}

	func pkgname(ctxt *Link, lib string) string {
	name := path.Clean(lib)

	// When using importcfg, we have the final package name.
	if ctxt.PackageFile != nil {
	return name
	}

	// runtime.a -> runtime, runtime.6 -> runtime
	pkg := name
	if len(pkg) >= 2 && pkg[len(pkg)-2] == '.' {
	pkg = pkg[:len(pkg)-2]
	}
	return pkg
	}

	func findlib(ctxt *Link, lib string) (string, bool) {
	name := path.Clean(lib)

	var pname string
	isshlib := false

	if ctxt.linkShared && ctxt.PackageShlib[name] != "" {
	pname = ctxt.PackageShlib[name]
	isshlib = true
	} else if ctxt.PackageFile != nil {
	pname = ctxt.PackageFile[name]
	if pname == "" {
	ctxt.Logf("cannot find package %s (using -importcfg)\n", name)
	return "", false
	}
	} else {
	if filepath.IsAbs(name) {
	pname = name
	} else {
	pkg := pkgname(ctxt, lib)
	// Add .a if needed; the new -importcfg modes
	// do not put .a into the package name anymore.
	// This only matters when people try to mix
	// compiles using -importcfg with links not using -importcfg,
	// such as when running quick things like
	// 'go tool compile x.go && go tool link x.o'
	// by hand against a standard library built using -importcfg.
	if !strings.HasSuffix(name, ".a") && !strings.HasSuffix(name, ".o") {
	name += ".a"
	}
	// try dot, -L "libdir", and then goroot.
	for _, dir := range ctxt.Libdir {
	if ctxt.linkShared {
	pname = filepath.Join(dir, pkg+".shlibname")
	if _, err := os.Stat(pname); err == nil {
	isshlib = true
	break
	}
	}
	pname = filepath.Join(dir, name)
	if _, err := os.Stat(pname); err == nil {
	break
	}
	}
	}
	pname = filepath.Clean(pname)
	}

	return pname, isshlib
	}

	func addlib(ctxt Link, src, obj, lib string, fingerprint goobj2.FingerprintType) sym.Library {
	pkg := pkgname(ctxt, lib)

	// already loaded?
	if l := ctxt.LibraryByPkg[pkg]; l != nil {
	checkFingerprint(l, l.Fingerprint, src, fingerprint)
	return l
	}

	pname, isshlib := findlib(ctxt, lib)

	if ctxt.Debugvlog > 1 {
	ctxt.Logf("addlib: %s %s pulls in %s isshlib %v\n", obj, src, pname, isshlib)
	}

	if isshlib {
	return addlibpath(ctxt, src, obj, "", pkg, pname, fingerprint)
	}
	return addlibpath(ctxt, src, obj, pname, pkg, "", fingerprint)
	}

	/*
	* add library to library list, return added library.
	* srcref: src file referring to package
	* objref: object file referring to package
	* file: object file, e.g., /home/rsc/go/pkg/container/vector.a
	* pkg: package import path, e.g. container/vector
	* shlib: path to shared library, or .shlibname file holding path
	* fingerprint: if not 0, expected fingerprint for import from srcref
	* fingerprint is 0 if the library is not imported (e.g. main)
	*/
	func addlibpath(ctxt Link, srcref, objref, file, pkg, shlib string, fingerprint goobj2.FingerprintType) sym.Library {
	if l := ctxt.LibraryByPkg[pkg]; l != nil {
	return l
	}

	if ctxt.Debugvlog > 1 {
	ctxt.Logf("addlibpath: srcref: %s objref: %s file: %s pkg: %s shlib: %s fingerprint: %x\n", srcref, objref, file, pkg, shlib, fingerprint)
	}

	l := &sym.Library{}
	ctxt.LibraryByPkg[pkg] = l
	ctxt.Library = append(ctxt.Library, l)
	l.Objref = objref
	l.Srcref = srcref
	l.File = file
	l.Pkg = pkg
	l.Fingerprint = fingerprint
	if shlib != "" {
	if strings.HasSuffix(shlib, ".shlibname") {
	data, err := ioutil.ReadFile(shlib)
	if err != nil {
	Errorf(nil, "cannot read %s: %v", shlib, err)
	}
	shlib = strings.TrimSpace(string(data))
	}
	l.Shlib = shlib
	}
	return l
	}

	func atolwhex(s string) int64 {
	n, _ := strconv.ParseInt(s, 0, 64)
	return n
	}

	// PrepareAddmoduledata returns a symbol builder that target-specific
	// code can use to build up the linker-generated go.link.addmoduledata
	// function, along with the sym for runtime.addmoduledata itself. If
	// this function is not needed (for example in cases where we're
	// linking a module that contains the runtime) the returned builder
	// will be nil.
	func PrepareAddmoduledata(ctxt Link) (loader.SymbolBuilder, loader.Sym) {
	if !ctxt.DynlinkingGo() {
	return nil, 0
	}
	amd := ctxt.loader.LookupOrCreateSym("runtime.addmoduledata", 0)
	if ctxt.loader.SymType(amd) == sym.STEXT && ctxt.BuildMode != BuildModePlugin {
	// we're linking a module containing the runtime -> no need for
	// an init function
	return nil, 0
	}
	ctxt.loader.SetAttrReachable(amd, true)

	// Create a new init func text symbol. Caller will populate this
	// sym with arch-specific content.
	ifs := ctxt.loader.LookupOrCreateSym("go.link.addmoduledata", 0)
	initfunc := ctxt.loader.MakeSymbolUpdater(ifs)
	ctxt.loader.SetAttrReachable(ifs, true)
	ctxt.loader.SetAttrLocal(ifs, true)
	initfunc.SetType(sym.STEXT)

	// Add the init func and/or addmoduledata to Textp2.
	if ctxt.BuildMode == BuildModePlugin {
	ctxt.Textp2 = append(ctxt.Textp2, amd)
	}
	ctxt.Textp2 = append(ctxt.Textp2, initfunc.Sym())

	// Create an init array entry
	amdi := ctxt.loader.LookupOrCreateSym("go.link.addmoduledatainit", 0)
	initarray_entry := ctxt.loader.MakeSymbolUpdater(amdi)
	ctxt.loader.SetAttrReachable(amdi, true)
	ctxt.loader.SetAttrLocal(amdi, true)
	initarray_entry.SetType(sym.SINITARR)
	initarray_entry.AddAddr(ctxt.Arch, ifs)

	return initfunc, amd
	}