1 // Copyright 2009 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package obj 6 7 import ( 8 "fmt" 9 "os" 10 "strings" 11 ) 12 13 // go-specific code shared across loaders (5l, 6l, 8l). 14 15 var ( 16 Framepointer_enabled int 17 Fieldtrack_enabled int 18 ) 19 20 // Toolchain experiments. 21 // These are controlled by the GOEXPERIMENT environment 22 // variable recorded when the toolchain is built. 23 // This list is also known to cmd/gc. 24 var exper = []struct { 25 name string 26 val *int 27 }{ 28 {"fieldtrack", &Fieldtrack_enabled}, 29 {"framepointer", &Framepointer_enabled}, 30 } 31 32 func addexp(s string) { 33 for i := 0; i < len(exper); i++ { 34 if exper[i].name == s { 35 if exper[i].val != nil { 36 *exper[i].val = 1 37 } 38 return 39 } 40 } 41 42 fmt.Printf("unknown experiment %s\n", s) 43 os.Exit(2) 44 } 45 46 func init() { 47 for _, f := range strings.Split(goexperiment, ",") { 48 if f != "" { 49 addexp(f) 50 } 51 } 52 } 53 54 func Nopout(p *Prog) { 55 p.As = ANOP 56 p.Scond = 0 57 p.From = Addr{} 58 p.From3 = nil 59 p.Reg = 0 60 p.To = Addr{} 61 } 62 63 func Nocache(p *Prog) { 64 p.Optab = 0 65 p.From.Class = 0 66 if p.From3 != nil { 67 p.From3.Class = 0 68 } 69 p.To.Class = 0 70 } 71 72 func Expstring() string { 73 buf := "X" 74 for i := range exper { 75 if *exper[i].val != 0 { 76 buf += "," + exper[i].name 77 } 78 } 79 if buf == "X" { 80 buf += ",none" 81 } 82 return "X:" + buf[2:] 83 } 84
