go/src/cmd/internal/obj/ld.go

// Derived from Inferno utils/6l/obj.c and utils/6l/span.c
// http://code.google.com/p/inferno-os/source/browse/utils/6l/obj.c
// http://code.google.com/p/inferno-os/source/browse/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 obj

import (
	"fmt"
	"os"
	"path"
	"strings"
)

func addlib(ctxt *Link, src, obj, pathname string) {
	name := path.Clean(pathname)

	// runtime.a -> runtime
	short := strings.TrimSuffix(name, ".a")

	// already loaded?
	for i := range ctxt.Library {
		if ctxt.Library[i].Pkg == short {
			return
		}
	}

	var pname string
	// runtime -> runtime.a for search
	if (!(ctxt.Windows != 0) && name[0] == '/') || (ctxt.Windows != 0 && name[1] == ':') {
		pname = name
	} else {
		// try dot, -L "libdir", and then goroot.
		for _, dir := range ctxt.Libdir {
			pname = dir + "/" + name
			if _, err := os.Stat(pname); !os.IsNotExist(err) {
				break
			}
		}
	}
	pname = path.Clean(pname)

	// runtime.a -> runtime
	pname = strings.TrimSuffix(pname, ".a")

	if ctxt.Debugvlog > 1 && ctxt.Bso != nil {
		fmt.Fprintf(ctxt.Bso, "%5.2f addlib: %s %s pulls in %s\n", Cputime(), obj, src, pname)
	}
	addlibpath(ctxt, src, obj, pname, name)
}

/*
 * add library to library list.
 *	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
 */
func addlibpath(ctxt *Link, srcref, objref, file, pkg string) {
	for _, lib := range ctxt.Library {
		if lib.File == file {
			return
		}
	}

	if ctxt.Debugvlog > 1 && ctxt.Bso != nil {
		fmt.Fprintf(ctxt.Bso, "%5.2f addlibpath: srcref: %s objref: %s file: %s pkg: %s\n", Cputime(), srcref, objref, file, pkg)
	}

	ctxt.Library = append(ctxt.Library, Library{
		Objref: objref,
		Srcref: srcref,
		File:   file,
		Pkg:    pkg,
	})
}

const (
	LOG = 5
)

func mkfwd(sym *LSym) {
	var p *Prog
	var i int
	var dwn [LOG]int32
	var cnt [LOG]int32
	var lst [LOG]*Prog

	for i = 0; i < LOG; i++ {
		if i == 0 {
			cnt[i] = 1
		} else {

			cnt[i] = LOG * cnt[i-1]
		}
		dwn[i] = 1
		lst[i] = nil
	}

	i = 0
	for p = sym.Text; p != nil && p.Link != nil; p = p.Link {
		i--
		if i < 0 {
			i = LOG - 1
		}
		p.Forwd = nil
		dwn[i]--
		if dwn[i] <= 0 {
			dwn[i] = cnt[i]
			if lst[i] != nil {
				lst[i].Forwd = p
			}
			lst[i] = p
		}
	}
}

func Copyp(ctxt *Link, q *Prog) *Prog {
	var p *Prog

	p = ctxt.Arch.Prg()
	*p = *q
	return p
}

func Appendp(ctxt *Link, q *Prog) *Prog {
	var p *Prog

	p = ctxt.Arch.Prg()
	p.Link = q.Link
	q.Link = p
	p.Lineno = q.Lineno
	p.Mode = q.Mode
	return p
}