cmd/link: remove -H elf flag

We create appropriate ELF files automatically based on GOOS. There's
no point in supporting -H elf flag, particularly since we need to emit
different flavors of ELF depending on GOOS anyway.

If that weren't reason enough, -H elf appears to be broken since at
least Go 1.4. At least I wasn't able to find a way to make use of it.

As best I can tell digging through commit history, -H elf is just an
artifact leftover from Plan 9's 6l linker.

Change-Id: I7393caaadbc60107bbd6bc99b976a4f4fe6b5451
Reviewed-on: https://go-review.googlesource.com/21343
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/internal/obj/link.go

@@ -716,7 +716,6 @@ const (
 	Hunknown = 0 + iota
 	Hdarwin
 	Hdragonfly
-	Helf
 	Hfreebsd
 	Hlinux
 	Hnacl

src/cmd/internal/obj/sym.go

@@ -44,7 +44,6 @@ var headers = []struct {
 }{
 	{"darwin", Hdarwin},
 	{"dragonfly", Hdragonfly},
-	{"elf", Helf},
 	{"freebsd", Hfreebsd},
 	{"linux", Hlinux},
 	{"android", Hlinux}, // must be after "linux" entry or else headstr(Hlinux) == "android"

src/cmd/link/internal/amd64/asm.go

@@ -671,8 +671,7 @@ func asmb() {
 		ld.Diag("unknown header type %d", ld.HEADTYPE)
 		fallthrough
 
-	case obj.Hplan9,
-		obj.Helf:
+	case obj.Hplan9:
 		break
 
 	case obj.Hdarwin:
@@ -702,8 +701,7 @@ func asmb() {
 		ld.Bso.Flush()
 		switch ld.HEADTYPE {
 		default:
-		case obj.Hplan9,
-			obj.Helf:
+		case obj.Hplan9:
 			ld.Debug['s'] = 1
 			symo = int64(ld.Segdata.Fileoff + ld.Segdata.Filelen)
 

src/cmd/link/internal/amd64/obj.go

@@ -136,19 +136,6 @@ func archinit() {
 			ld.INITRND = 0x200000
 		}
 
-	case obj.Helf: /* elf32 executable */
-		ld.HEADR = int32(ld.Rnd(52+3*32, 16))
-
-		if ld.INITTEXT == -1 {
-			ld.INITTEXT = 0x80110000
-		}
-		if ld.INITDAT == -1 {
-			ld.INITDAT = 0
-		}
-		if ld.INITRND == -1 {
-			ld.INITRND = 4096
-		}
-
 	case obj.Hdarwin: /* apple MACH */
 		ld.Machoinit()
 

src/cmd/link/internal/ld/sym.go

@@ -43,7 +43,6 @@ var headers = []struct {
 }{
 	{"darwin", obj.Hdarwin},
 	{"dragonfly", obj.Hdragonfly},
-	{"elf", obj.Helf},
 	{"freebsd", obj.Hfreebsd},
 	{"linux", obj.Hlinux},
 	{"android", obj.Hlinux}, // must be after "linux" entry or else headstr(Hlinux) == "android"