service/vendor/github.com/twitchyliquid64/golang-asm/objabi/util.go

204 lines
4.1 KiB
Go

// 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", "amd64")
GOOS = envOr("GOOS", "linux")
GO386 = envOr("GO386", "")
GOAMD64 = goamd64()
GOARM = goarm()
GOMIPS = gomips()
GOMIPS64 = gomips64()
GOPPC64 = goppc64()
GOWASM = gowasm()
GO_LDSO = ""
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", "7"); 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", "hardfloat"); 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", "hardfloat"); 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", "power8"); 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", "")
}
func init() {
for _, f := range strings.Split("", ",") {
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:]
}