github.com/dannin/go@v0.0.0-20161031215817-d35dfd405eaa/src/cmd/link/internal/ld/sym.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/internal/obj"
    36  	"cmd/internal/sys"
    37  	"log"
    38  )
    39  
    40  func linknew(arch *sys.Arch) *Link {
    41  	ctxt := &Link{
    42  		Syms: &Symbols{
    43  			hash: []map[string]*Symbol{
    44  				// preallocate about 2mb for hash of
    45  				// non static symbols
    46  				make(map[string]*Symbol, 100000),
    47  			},
    48  			Allsym: make([]*Symbol, 0, 100000),
    49  		},
    50  		Arch: arch,
    51  	}
    52  
    53  	if obj.GOARCH != arch.Name {
    54  		log.Fatalf("invalid obj.GOARCH %s (want %s)", obj.GOARCH, arch.Name)
    55  	}
    56  
    57  	return ctxt
    58  }
    59  
    60  // computeTLSOffset records the thread-local storage offset.
    61  func (ctxt *Link) computeTLSOffset() {
    62  	switch Headtype {
    63  	default:
    64  		log.Fatalf("unknown thread-local storage offset for %v", Headtype)
    65  
    66  	case obj.Hplan9, obj.Hwindows, obj.Hwindowsgui:
    67  		break
    68  
    69  		/*
    70  		 * ELF uses TLS offset negative from FS.
    71  		 * Translate 0(FS) and 8(FS) into -16(FS) and -8(FS).
    72  		 * Known to low-level assembly in package runtime and runtime/cgo.
    73  		 */
    74  	case obj.Hlinux,
    75  		obj.Hfreebsd,
    76  		obj.Hnetbsd,
    77  		obj.Hopenbsd,
    78  		obj.Hdragonfly,
    79  		obj.Hsolaris:
    80  		if obj.GOOS == "android" {
    81  			switch ctxt.Arch.Family {
    82  			case sys.AMD64:
    83  				// Android/amd64 constant - offset from 0(FS) to our TLS slot.
    84  				// Explained in src/runtime/cgo/gcc_android_*.c
    85  				ctxt.Tlsoffset = 0x1d0
    86  			case sys.I386:
    87  				// Android/386 constant - offset from 0(GS) to our TLS slot.
    88  				ctxt.Tlsoffset = 0xf8
    89  			default:
    90  				ctxt.Tlsoffset = -1 * ctxt.Arch.PtrSize
    91  			}
    92  		} else {
    93  			ctxt.Tlsoffset = -1 * ctxt.Arch.PtrSize
    94  		}
    95  
    96  	case obj.Hnacl:
    97  		switch ctxt.Arch.Family {
    98  		default:
    99  			log.Fatalf("unknown thread-local storage offset for nacl/%s", ctxt.Arch.Name)
   100  
   101  		case sys.ARM:
   102  			ctxt.Tlsoffset = 0
   103  
   104  		case sys.AMD64:
   105  			ctxt.Tlsoffset = 0
   106  
   107  		case sys.I386:
   108  			ctxt.Tlsoffset = -8
   109  		}
   110  
   111  		/*
   112  		 * OS X system constants - offset from 0(GS) to our TLS.
   113  		 * Explained in src/runtime/cgo/gcc_darwin_*.c.
   114  		 */
   115  	case obj.Hdarwin:
   116  		switch ctxt.Arch.Family {
   117  		default:
   118  			log.Fatalf("unknown thread-local storage offset for darwin/%s", ctxt.Arch.Name)
   119  
   120  		case sys.ARM:
   121  			ctxt.Tlsoffset = 0 // dummy value, not needed
   122  
   123  		case sys.AMD64:
   124  			ctxt.Tlsoffset = 0x8a0
   125  
   126  		case sys.ARM64:
   127  			ctxt.Tlsoffset = 0 // dummy value, not needed
   128  
   129  		case sys.I386:
   130  			ctxt.Tlsoffset = 0x468
   131  		}
   132  	}
   133  
   134  }