1// Derived from Inferno utils/6l/obj.c and utils/6l/span.c
2// https://bitbucket.org/inferno-os/inferno-os/src/master/utils/6l/obj.c
3// https://bitbucket.org/inferno-os/inferno-os/src/master/utils/6l/span.c
4//
5//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
6//	Portions Copyright © 1995-1997 C H Forsyth ([email protected])
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 ([email protected])
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
32package ld
33
34import (
35	"cmd/internal/objabi"
36	"cmd/internal/sys"
37	"cmd/link/internal/loader"
38	"cmd/link/internal/sym"
39	"internal/buildcfg"
40	"log"
41	"runtime"
42)
43
44func linknew(arch *sys.Arch) *Link {
45	ler := loader.ErrorReporter{AfterErrorAction: afterErrorAction}
46	ctxt := &Link{
47		Target:        Target{Arch: arch},
48		version:       sym.SymVerStatic,
49		outSem:        make(chan int, 2*runtime.GOMAXPROCS(0)),
50		Out:           NewOutBuf(arch),
51		LibraryByPkg:  make(map[string]*sym.Library),
52		numelfsym:     1,
53		ErrorReporter: ErrorReporter{ErrorReporter: ler},
54		generatorSyms: make(map[loader.Sym]generatorFunc),
55	}
56
57	if buildcfg.GOARCH != arch.Name {
58		log.Fatalf("invalid buildcfg.GOARCH %s (want %s)", buildcfg.GOARCH, arch.Name)
59	}
60
61	AtExit(func() {
62		if nerrors > 0 {
63			ctxt.Out.ErrorClose()
64			mayberemoveoutfile()
65		}
66	})
67
68	return ctxt
69}
70
71// computeTLSOffset records the thread-local storage offset.
72// Not used for Android where the TLS offset is determined at runtime.
73func (ctxt *Link) computeTLSOffset() {
74	switch ctxt.HeadType {
75	default:
76		log.Fatalf("unknown thread-local storage offset for %v", ctxt.HeadType)
77
78	case objabi.Hplan9, objabi.Hwindows, objabi.Hjs, objabi.Hwasip1, objabi.Haix:
79		break
80
81	case objabi.Hlinux,
82		objabi.Hfreebsd,
83		objabi.Hnetbsd,
84		objabi.Hopenbsd,
85		objabi.Hdragonfly,
86		objabi.Hsolaris:
87		/*
88		 * ELF uses TLS offset negative from FS.
89		 * Translate 0(FS) and 8(FS) into -16(FS) and -8(FS).
90		 * Known to low-level assembly in package runtime and runtime/cgo.
91		 */
92		ctxt.Tlsoffset = -1 * ctxt.Arch.PtrSize
93
94	case objabi.Hdarwin:
95		/*
96		 * OS X system constants - offset from 0(GS) to our TLS.
97		 */
98		switch ctxt.Arch.Family {
99		default:
100			log.Fatalf("unknown thread-local storage offset for darwin/%s", ctxt.Arch.Name)
101
102			/*
103			 * For x86, Apple has reserved a slot in the TLS for Go. See issue 23617.
104			 * That slot is at offset 0x30 on amd64.
105			 * The slot will hold the G pointer.
106			 * These constants should match those in runtime/sys_darwin_amd64.s
107			 * and runtime/cgo/gcc_darwin_amd64.c.
108			 */
109		case sys.AMD64:
110			ctxt.Tlsoffset = 0x30
111
112		case sys.ARM64:
113			ctxt.Tlsoffset = 0 // dummy value, not needed
114		}
115	}
116
117}
118