cmd/link: add support for GOARCH=mips{,le}

Only internal linking without cgo is supported for now.

Change-Id: I772d2ba496a613c78bee7e93f29e9538e6407bdc
Reviewed-on: https://go-review.googlesource.com/31481
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

4 files changed, 376 insertions, 1 deletions

diff --git a/src/cmd/link/internal/ld/elf.go b/src/cmd/link/internal/ld/elf.go
index bfd449847b..b4d5aae27a 100644
--- a/src/cmd/link/internal/ld/elf.go
+++ b/src/cmd/link/internal/ld/elf.go
@@ -2199,7 +2199,7 @@ func Asmbelf(ctxt *Link, symo int64) {
 	switch SysArch.Family {
 	default:
 		Exitf("unknown architecture in asmbelf: %v", SysArch.Family)
-	case sys.MIPS64:
+	case sys.MIPS, sys.MIPS64:
 		eh.machine = EM_MIPS
 	case sys.ARM:
 		eh.machine = EM_ARM
diff --git a/src/cmd/link/internal/mips/asm.go b/src/cmd/link/internal/mips/asm.go
new file mode 100644
index 0000000000..b2c72893a1
--- /dev/null
+++ b/src/cmd/link/internal/mips/asm.go
@@ -0,0 +1,191 @@
+// Inferno utils/5l/asm.c
+// https://bitbucket.org/inferno-os/inferno-os/src/default/utils/5l/asm.c
+//
+//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
+//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
+//	Portions Copyright © 1997-1999 Vita Nuova Limited
+//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
+//	Portions Copyright © 2004,2006 Bruce Ellis
+//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
+//	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
+//	Portions Copyright © 2016 The Go Authors. All rights reserved.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package mips
+
+import (
+	"cmd/internal/obj"
+	"cmd/link/internal/ld"
+	"fmt"
+	"log"
+)
+
+func gentext(ctxt *ld.Link) {
+	return
+}
+
+func adddynrel(ctxt *ld.Link, s *ld.Symbol, r *ld.Reloc) bool {
+	log.Fatalf("adddynrel not implemented")
+	return false
+}
+
+func elfreloc1(ctxt *ld.Link, r *ld.Reloc, sectoff int64) int {
+	return -1
+}
+
+func elfsetupplt(ctxt *ld.Link) {
+	return
+}
+
+func machoreloc1(s *ld.Symbol, r *ld.Reloc, sectoff int64) int {
+	return -1
+}
+
+func archreloc(ctxt *ld.Link, r *ld.Reloc, s *ld.Symbol, val *int64) int {
+	if ld.Linkmode == ld.LinkExternal {
+		return -1
+	}
+
+	switch r.Type {
+	case obj.R_CONST:
+		*val = r.Add
+		return 0
+
+	case obj.R_GOTOFF:
+		*val = ld.Symaddr(r.Sym) + r.Add - ld.Symaddr(ctxt.Syms.Lookup(".got", 0))
+		return 0
+
+	case obj.R_ADDRMIPS,
+		obj.R_ADDRMIPSU:
+		t := ld.Symaddr(r.Sym) + r.Add
+		o1 := ld.SysArch.ByteOrder.Uint32(s.P[r.Off:])
+		if r.Type == obj.R_ADDRMIPS {
+			*val = int64(o1&0xffff0000 | uint32(t)&0xffff)
+		} else {
+			*val = int64(o1&0xffff0000 | uint32((t+1<<15)>>16)&0xffff)
+		}
+		return 0
+
+	case obj.R_CALLMIPS,
+		obj.R_JMPMIPS:
+		// Low 26 bits = (S + A) >> 2
+		t := ld.Symaddr(r.Sym) + r.Add
+		o1 := ld.SysArch.ByteOrder.Uint32(s.P[r.Off:])
+		*val = int64(o1&0xfc000000 | uint32(t>>2)&^0xfc000000)
+		return 0
+	}
+
+	return -1
+}
+
+func archrelocvariant(ctxt *ld.Link, r *ld.Reloc, s *ld.Symbol, t int64) int64 {
+	return -1
+}
+
+func asmb(ctxt *ld.Link) {
+	if ctxt.Debugvlog != 0 {
+		ctxt.Logf("%5.2f asmb\n", obj.Cputime())
+	}
+
+	if ld.Iself {
+		ld.Asmbelfsetup()
+	}
+
+	sect := ld.Segtext.Sect
+	ld.Cseek(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff))
+	ld.Codeblk(ctxt, int64(sect.Vaddr), int64(sect.Length))
+	for sect = sect.Next; sect != nil; sect = sect.Next {
+		ld.Cseek(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff))
+		ld.Datblk(ctxt, int64(sect.Vaddr), int64(sect.Length))
+	}
+
+	if ld.Segrodata.Filelen > 0 {
+		if ctxt.Debugvlog != 0 {
+			ctxt.Logf("%5.2f rodatblk\n", obj.Cputime())
+		}
+
+		ld.Cseek(int64(ld.Segrodata.Fileoff))
+		ld.Datblk(ctxt, int64(ld.Segrodata.Vaddr), int64(ld.Segrodata.Filelen))
+	}
+
+	if ctxt.Debugvlog != 0 {
+		ctxt.Logf("%5.2f datblk\n", obj.Cputime())
+	}
+
+	ld.Cseek(int64(ld.Segdata.Fileoff))
+	ld.Datblk(ctxt, int64(ld.Segdata.Vaddr), int64(ld.Segdata.Filelen))
+
+	ld.Cseek(int64(ld.Segdwarf.Fileoff))
+	ld.Dwarfblk(ctxt, int64(ld.Segdwarf.Vaddr), int64(ld.Segdwarf.Filelen))
+
+	/* output symbol table */
+	ld.Symsize = 0
+
+	ld.Lcsize = 0
+	symo := uint32(0)
+	if !*ld.FlagS {
+		if !ld.Iself {
+			ld.Errorf(nil, "unsupported executable format")
+		}
+		if ctxt.Debugvlog != 0 {
+			ctxt.Logf("%5.2f sym\n", obj.Cputime())
+		}
+		symo = uint32(ld.Segdwarf.Fileoff + ld.Segdwarf.Filelen)
+		symo = uint32(ld.Rnd(int64(symo), int64(*ld.FlagRound)))
+
+		ld.Cseek(int64(symo))
+		if ctxt.Debugvlog != 0 {
+			ctxt.Logf("%5.2f elfsym\n", obj.Cputime())
+		}
+		ld.Asmelfsym(ctxt)
+		ld.Cflush()
+		ld.Cwrite(ld.Elfstrdat)
+
+		if ctxt.Debugvlog != 0 {
+			ctxt.Logf("%5.2f dwarf\n", obj.Cputime())
+		}
+
+		if ld.Linkmode == ld.LinkExternal {
+			ld.Elfemitreloc(ctxt)
+		}
+	}
+
+	if ctxt.Debugvlog != 0 {
+		ctxt.Logf("%5.2f header\n", obj.Cputime())
+	}
+
+	ld.Cseek(0)
+	switch ld.Headtype {
+	default:
+		ld.Errorf(nil, "unsupported operating system")
+	case obj.Hlinux:
+		ld.Asmbelf(ctxt, int64(symo))
+	}
+
+	ld.Cflush()
+	if *ld.FlagC {
+		fmt.Printf("textsize=%d\n", ld.Segtext.Filelen)
+		fmt.Printf("datsize=%d\n", ld.Segdata.Filelen)
+		fmt.Printf("bsssize=%d\n", ld.Segdata.Length-ld.Segdata.Filelen)
+		fmt.Printf("symsize=%d\n", ld.Symsize)
+		fmt.Printf("lcsize=%d\n", ld.Lcsize)
+		fmt.Printf("total=%d\n", ld.Segtext.Filelen+ld.Segdata.Length+uint64(ld.Symsize)+uint64(ld.Lcsize))
+	}
+}
diff --git a/src/cmd/link/internal/mips/l.go b/src/cmd/link/internal/mips/l.go
new file mode 100644
index 0000000000..adbde40f7c
--- /dev/null
+++ b/src/cmd/link/internal/mips/l.go
@@ -0,0 +1,74 @@
+// Inferno utils/5l/asm.c
+// https://bitbucket.org/inferno-os/inferno-os/src/default/utils/5l/asm.c
+//
+//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
+//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
+//	Portions Copyright © 1997-1999 Vita Nuova Limited
+//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
+//	Portions Copyright © 2004,2006 Bruce Ellis
+//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
+//	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
+//	Portions Copyright © 2016 The Go Authors.  All rights reserved.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package mips
+
+// Writing object files.
+
+// cmd/9l/l.h from Vita Nuova.
+//
+//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
+//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
+//	Portions Copyright © 1997-1999 Vita Nuova Limited
+//	Portions Copyright © 2000-2008 Vita Nuova Holdings Limited (www.vitanuova.com)
+//	Portions Copyright © 2004,2006 Bruce Ellis
+//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
+//	Revisions Copyright © 2000-2008 Lucent Technologies Inc. and others
+//	Portions Copyright © 2016 The Go Authors.  All rights reserved.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+const (
+	MaxAlign  = 32 // max data alignment
+	MinAlign  = 1  // min data alignment
+	FuncAlign = 4
+)
+
+/* Used by ../internal/ld/dwarf.go */
+const (
+	DWARFREGSP = 29
+	DWARFREGLR = 31
+)
diff --git a/src/cmd/link/internal/mips/obj.go b/src/cmd/link/internal/mips/obj.go
new file mode 100644
index 0000000000..a33387658c
--- /dev/null
+++ b/src/cmd/link/internal/mips/obj.go
@@ -0,0 +1,110 @@
+// Inferno utils/5l/obj.c
+// https://bitbucket.org/inferno-os/inferno-os/src/default/utils/5l/obj.c
+//
+//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
+//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
+//	Portions Copyright © 1997-1999 Vita Nuova Limited
+//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
+//	Portions Copyright © 2004,2006 Bruce Ellis
+//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
+//	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
+//	Portions Copyright © 2016 The Go Authors. All rights reserved.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package mips
+
+import (
+	"cmd/internal/obj"
+	"cmd/internal/sys"
+	"cmd/link/internal/ld"
+	"fmt"
+)
+
+// Reading object files.
+
+func Init() {
+	if obj.GOARCH == "mipsle" {
+		ld.SysArch = sys.ArchMIPSLE
+	} else {
+		ld.SysArch = sys.ArchMIPS
+	}
+
+	ld.Thearch.Funcalign = FuncAlign
+	ld.Thearch.Maxalign = MaxAlign
+	ld.Thearch.Minalign = MinAlign
+	ld.Thearch.Dwarfregsp = DWARFREGSP
+	ld.Thearch.Dwarfreglr = DWARFREGLR
+
+	ld.Thearch.Adddynrel = adddynrel
+	ld.Thearch.Archinit = archinit
+	ld.Thearch.Archreloc = archreloc
+	ld.Thearch.Archrelocvariant = archrelocvariant
+	ld.Thearch.Asmb = asmb
+	ld.Thearch.Elfreloc1 = elfreloc1
+	ld.Thearch.Elfsetupplt = elfsetupplt
+	ld.Thearch.Gentext = gentext
+	ld.Thearch.Machoreloc1 = machoreloc1
+	if ld.SysArch == sys.ArchMIPSLE {
+		ld.Thearch.Lput = ld.Lputl
+		ld.Thearch.Wput = ld.Wputl
+		ld.Thearch.Vput = ld.Vputl
+		ld.Thearch.Append16 = ld.Append16l
+		ld.Thearch.Append32 = ld.Append32l
+		ld.Thearch.Append64 = ld.Append64l
+	} else {
+		ld.Thearch.Lput = ld.Lputb
+		ld.Thearch.Wput = ld.Wputb
+		ld.Thearch.Vput = ld.Vputb
+		ld.Thearch.Append16 = ld.Append16b
+		ld.Thearch.Append32 = ld.Append32b
+		ld.Thearch.Append64 = ld.Append64b
+	}
+
+	ld.Thearch.Linuxdynld = "/lib/ld.so.1"
+
+	ld.Thearch.Freebsddynld = "XXX"
+	ld.Thearch.Openbsddynld = "XXX"
+	ld.Thearch.Netbsddynld = "XXX"
+	ld.Thearch.Dragonflydynld = "XXX"
+	ld.Thearch.Solarisdynld = "XXX"
+}
+
+func archinit(ctxt *ld.Link) {
+	switch ld.Headtype {
+	default:
+		ld.Exitf("unknown -H option: %v", ld.Headtype)
+	case obj.Hlinux: /* mips elf */
+		ld.Elfinit(ctxt)
+		ld.HEADR = ld.ELFRESERVE
+		if *ld.FlagTextAddr == -1 {
+			*ld.FlagTextAddr = 0x10000 + int64(ld.HEADR)
+		}
+		if *ld.FlagDataAddr == -1 {
+			*ld.FlagDataAddr = 0
+		}
+		if *ld.FlagRound == -1 {
+			*ld.FlagRound = 0x10000
+		}
+	}
+
+	if *ld.FlagDataAddr != 0 && *ld.FlagRound != 0 {
+		fmt.Printf("warning: -D0x%x is ignored because of -R0x%x\n", uint64(*ld.FlagDataAddr), uint32(*ld.FlagRound))
+	}
+}