aboutsummaryrefslogtreecommitdiff
path: root/src/cmd/internal/objabi/util.go
blob: d2d6fdbda8d75ce038832c56fb44cd454bbd020d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package objabi

import (
	"fmt"
	"log"
	"os"
	"strings"
)

func envOr(key, value string) string {
	if x := os.Getenv(key); x != "" {
		return x
	}
	return value
}

var (
	defaultGOROOT string // set by linker

	GOROOT   = envOr("GOROOT", defaultGOROOT)
	GOARCH   = envOr("GOARCH", defaultGOARCH)
	GOOS     = envOr("GOOS", defaultGOOS)
	GO386    = envOr("GO386", defaultGO386)
	GOAMD64  = goamd64()
	GOARM    = goarm()
	GOMIPS   = gomips()
	GOMIPS64 = gomips64()
	GOPPC64  = goppc64()
	GOWASM   = gowasm()
	GO_LDSO  = defaultGO_LDSO
	Version  = version
)

const (
	ElfRelocOffset   = 256
	MachoRelocOffset = 2048           // reserve enough space for ELF relocations
	Go115AMD64       = "alignedjumps" // Should be "alignedjumps" or "normaljumps"; this replaces environment variable introduced in CL 219357.
)

// TODO(1.16): assuming no issues in 1.15 release, remove this and related constant.
func goamd64() string {
	return Go115AMD64
}

func goarm() int {
	switch v := envOr("GOARM", defaultGOARM); v {
	case "5":
		return 5
	case "6":
		return 6
	case "7":
		return 7
	}
	// Fail here, rather than validate at multiple call sites.
	log.Fatalf("Invalid GOARM value. Must be 5, 6, or 7.")
	panic("unreachable")
}

func gomips() string {
	switch v := envOr("GOMIPS", defaultGOMIPS); v {
	case "hardfloat", "softfloat":
		return v
	}
	log.Fatalf("Invalid GOMIPS value. Must be hardfloat or softfloat.")
	panic("unreachable")
}

func gomips64() string {
	switch v := envOr("GOMIPS64", defaultGOMIPS64); v {
	case "hardfloat", "softfloat":
		return v
	}
	log.Fatalf("Invalid GOMIPS64 value. Must be hardfloat or softfloat.")
	panic("unreachable")
}

func goppc64() int {
	switch v := envOr("GOPPC64", defaultGOPPC64); v {
	case "power8":
		return 8
	case "power9":
		return 9
	}
	log.Fatalf("Invalid GOPPC64 value. Must be power8 or power9.")
	panic("unreachable")
}

type gowasmFeatures struct {
	SignExt bool
	SatConv bool
}

func (f gowasmFeatures) String() string {
	var flags []string
	if f.SatConv {
		flags = append(flags, "satconv")
	}
	if f.SignExt {
		flags = append(flags, "signext")
	}
	return strings.Join(flags, ",")
}

func gowasm() (f gowasmFeatures) {
	for _, opt := range strings.Split(envOr("GOWASM", ""), ",") {
		switch opt {
		case "satconv":
			f.SatConv = true
		case "signext":
			f.SignExt = true
		case "":
			// ignore
		default:
			log.Fatalf("Invalid GOWASM value. No such feature: " + opt)
		}
	}
	return
}

func Getgoextlinkenabled() string {
	return envOr("GO_EXTLINK_ENABLED", defaultGO_EXTLINK_ENABLED)
}

func init() {
	for _, f := range strings.Split(goexperiment, ",") {
		if f != "" {
			addexp(f)
		}
	}

	// regabi is only supported on amd64.
	if GOARCH != "amd64" {
		Regabi_enabled = 0
	}
}

// Note: must agree with runtime.framepointer_enabled.
var Framepointer_enabled = GOARCH == "amd64" || GOARCH == "arm64" && (GOOS == "linux" || GOOS == "darwin")

func addexp(s string) {
	// Could do general integer parsing here, but the runtime copy doesn't yet.
	v := 1
	name := s
	if len(name) > 2 && name[:2] == "no" {
		v = 0
		name = name[2:]
	}
	for i := 0; i < len(exper); i++ {
		if exper[i].name == name {
			if exper[i].val != nil {
				*exper[i].val = v
			}
			return
		}
	}

	fmt.Printf("unknown experiment %s\n", s)
	os.Exit(2)
}

var (
	Fieldtrack_enabled        int
	Preemptibleloops_enabled  int
	Staticlockranking_enabled int
	Regabi_enabled            int
)

// Toolchain experiments.
// These are controlled by the GOEXPERIMENT environment
// variable recorded when the toolchain is built.
// This list is also known to cmd/gc.
var exper = []struct {
	name string
	val  *int
}{
	{"fieldtrack", &Fieldtrack_enabled},
	{"preemptibleloops", &Preemptibleloops_enabled},
	{"staticlockranking", &Staticlockranking_enabled},
	{"regabi", &Regabi_enabled},
}

var defaultExpstring = Expstring()

func DefaultExpstring() string {
	return defaultExpstring
}

func Expstring() string {
	buf := "X"
	for i := range exper {
		if *exper[i].val != 0 {
			buf += "," + exper[i].name
		}
	}
	if buf == "X" {
		buf += ",none"
	}
	return "X:" + buf[2:]
}