Adding upstream version 1.16.10.upstream/1.16.10upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1048 insertions, 0 deletions

diff --git a/src/cmd/link/internal/arm64/asm.go b/src/cmd/link/internal/arm64/asm.go
new file mode 100644
index 0000000..14a20a1
--- /dev/null
+++ b/src/cmd/link/internal/arm64/asm.go
@@ -0,0 +1,1048 @@
+// Inferno utils/5l/asm.c
+// https://bitbucket.org/inferno-os/inferno-os/src/master/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 © 2009 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 arm64
+
+import (
+	"cmd/internal/objabi"
+	"cmd/internal/sys"
+	"cmd/link/internal/ld"
+	"cmd/link/internal/loader"
+	"cmd/link/internal/sym"
+	"debug/elf"
+	"fmt"
+	"log"
+)
+
+func gentext(ctxt *ld.Link, ldr *loader.Loader) {
+	initfunc, addmoduledata := ld.PrepareAddmoduledata(ctxt)
+	if initfunc == nil {
+		return
+	}
+
+	o := func(op uint32) {
+		initfunc.AddUint32(ctxt.Arch, op)
+	}
+	// 0000000000000000 <local.dso_init>:
+	// 0:	90000000 	adrp	x0, 0 <runtime.firstmoduledata>
+	// 	0: R_AARCH64_ADR_PREL_PG_HI21	local.moduledata
+	// 4:	91000000 	add	x0, x0, #0x0
+	// 	4: R_AARCH64_ADD_ABS_LO12_NC	local.moduledata
+	o(0x90000000)
+	o(0x91000000)
+	rel, _ := initfunc.AddRel(objabi.R_ADDRARM64)
+	rel.SetOff(0)
+	rel.SetSiz(8)
+	rel.SetSym(ctxt.Moduledata)
+
+	// 8:	14000000 	b	0 <runtime.addmoduledata>
+	// 	8: R_AARCH64_CALL26	runtime.addmoduledata
+	o(0x14000000)
+	rel2, _ := initfunc.AddRel(objabi.R_CALLARM64)
+	rel2.SetOff(8)
+	rel2.SetSiz(4)
+	rel2.SetSym(addmoduledata)
+}
+
+func adddynrel(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loader.Sym, r loader.Reloc, rIdx int) bool {
+	targ := r.Sym()
+	var targType sym.SymKind
+	if targ != 0 {
+		targType = ldr.SymType(targ)
+	}
+
+	const pcrel = 1
+	switch r.Type() {
+	default:
+		if r.Type() >= objabi.ElfRelocOffset {
+			ldr.Errorf(s, "unexpected relocation type %d (%s)", r.Type(), sym.RelocName(target.Arch, r.Type()))
+			return false
+		}
+
+	// Handle relocations found in ELF object files.
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_PREL32):
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected R_AARCH64_PREL32 relocation for dynamic symbol %s", ldr.SymName(targ))
+		}
+		// TODO(mwhudson): the test of VisibilityHidden here probably doesn't make
+		// sense and should be removed when someone has thought about it properly.
+		if (targType == 0 || targType == sym.SXREF) && !ldr.AttrVisibilityHidden(targ) {
+			ldr.Errorf(s, "unknown symbol %s in pcrel", ldr.SymName(targ))
+		}
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_PCREL)
+		su.SetRelocAdd(rIdx, r.Add()+4)
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_PREL64):
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected R_AARCH64_PREL64 relocation for dynamic symbol %s", ldr.SymName(targ))
+		}
+		if targType == 0 || targType == sym.SXREF {
+			ldr.Errorf(s, "unknown symbol %s in pcrel", ldr.SymName(targ))
+		}
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_PCREL)
+		su.SetRelocAdd(rIdx, r.Add()+8)
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_CALL26),
+		objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_JUMP26):
+		if targType == sym.SDYNIMPORT {
+			addpltsym(target, ldr, syms, targ)
+			su := ldr.MakeSymbolUpdater(s)
+			su.SetRelocSym(rIdx, syms.PLT)
+			su.SetRelocAdd(rIdx, r.Add()+int64(ldr.SymPlt(targ)))
+		}
+		if (targType == 0 || targType == sym.SXREF) && !ldr.AttrVisibilityHidden(targ) {
+			ldr.Errorf(s, "unknown symbol %s in callarm64", ldr.SymName(targ))
+		}
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_CALLARM64)
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_ADR_GOT_PAGE),
+		objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_LD64_GOT_LO12_NC):
+		if targType != sym.SDYNIMPORT {
+			// have symbol
+			// TODO: turn LDR of GOT entry into ADR of symbol itself
+		}
+
+		// fall back to using GOT
+		// TODO: just needs relocation, no need to put in .dynsym
+		ld.AddGotSym(target, ldr, syms, targ, uint32(elf.R_AARCH64_GLOB_DAT))
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_ARM64_GOT)
+		su.SetRelocSym(rIdx, syms.GOT)
+		su.SetRelocAdd(rIdx, r.Add()+int64(ldr.SymGot(targ)))
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_ADR_PREL_PG_HI21),
+		objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_ADD_ABS_LO12_NC):
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected relocation for dynamic symbol %s", ldr.SymName(targ))
+		}
+		if targType == 0 || targType == sym.SXREF {
+			ldr.Errorf(s, "unknown symbol %s", ldr.SymName(targ))
+		}
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_ARM64_PCREL)
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_ABS64):
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected R_AARCH64_ABS64 relocation for dynamic symbol %s", ldr.SymName(targ))
+		}
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_ADDR)
+		if target.IsPIE() && target.IsInternal() {
+			// For internal linking PIE, this R_ADDR relocation cannot
+			// be resolved statically. We need to generate a dynamic
+			// relocation. Let the code below handle it.
+			break
+		}
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_LDST8_ABS_LO12_NC):
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected relocation for dynamic symbol %s", ldr.SymName(targ))
+		}
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_ARM64_LDST8)
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_LDST16_ABS_LO12_NC):
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected relocation for dynamic symbol %s", ldr.SymName(targ))
+		}
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_ARM64_LDST16)
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_LDST32_ABS_LO12_NC):
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected relocation for dynamic symbol %s", ldr.SymName(targ))
+		}
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_ARM64_LDST32)
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_LDST64_ABS_LO12_NC):
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected relocation for dynamic symbol %s", ldr.SymName(targ))
+		}
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_ARM64_LDST64)
+
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_LDST128_ABS_LO12_NC):
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected relocation for dynamic symbol %s", ldr.SymName(targ))
+		}
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_ARM64_LDST128)
+		return true
+
+	// Handle relocations found in Mach-O object files.
+	case objabi.MachoRelocOffset + ld.MACHO_ARM64_RELOC_UNSIGNED*2:
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected reloc for dynamic symbol %s", ldr.SymName(targ))
+		}
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_ADDR)
+		if target.IsPIE() && target.IsInternal() {
+			// For internal linking PIE, this R_ADDR relocation cannot
+			// be resolved statically. We need to generate a dynamic
+			// relocation. Let the code below handle it.
+			break
+		}
+		return true
+
+	case objabi.MachoRelocOffset + ld.MACHO_ARM64_RELOC_BRANCH26*2 + pcrel:
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_CALLARM64)
+		if targType == sym.SDYNIMPORT {
+			addpltsym(target, ldr, syms, targ)
+			su.SetRelocSym(rIdx, syms.PLT)
+			su.SetRelocAdd(rIdx, int64(ldr.SymPlt(targ)))
+		}
+		return true
+
+	case objabi.MachoRelocOffset + ld.MACHO_ARM64_RELOC_PAGE21*2 + pcrel,
+		objabi.MachoRelocOffset + ld.MACHO_ARM64_RELOC_PAGEOFF12*2:
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected relocation for dynamic symbol %s", ldr.SymName(targ))
+		}
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_ARM64_PCREL)
+		return true
+
+	case objabi.MachoRelocOffset + ld.MACHO_ARM64_RELOC_GOT_LOAD_PAGE21*2 + pcrel,
+		objabi.MachoRelocOffset + ld.MACHO_ARM64_RELOC_GOT_LOAD_PAGEOFF12*2:
+		if targType != sym.SDYNIMPORT {
+			// have symbol
+			// turn MOVD sym@GOT (adrp+ldr) into MOVD $sym (adrp+add)
+			data := ldr.Data(s)
+			off := r.Off()
+			if int(off+3) >= len(data) {
+				ldr.Errorf(s, "unexpected GOT_LOAD reloc for non-dynamic symbol %s", ldr.SymName(targ))
+				return false
+			}
+			o := target.Arch.ByteOrder.Uint32(data[off:])
+			su := ldr.MakeSymbolUpdater(s)
+			switch {
+			case (o>>24)&0x9f == 0x90: // adrp
+				// keep instruction unchanged, change relocation type below
+			case o>>24 == 0xf9: // ldr
+				// rewrite to add
+				o = (0x91 << 24) | (o & (1<<22 - 1))
+				su.MakeWritable()
+				su.SetUint32(target.Arch, int64(off), o)
+			default:
+				ldr.Errorf(s, "unexpected GOT_LOAD reloc for non-dynamic symbol %s", ldr.SymName(targ))
+				return false
+			}
+			su.SetRelocType(rIdx, objabi.R_ARM64_PCREL)
+			return true
+		}
+		ld.AddGotSym(target, ldr, syms, targ, 0)
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_ARM64_GOT)
+		su.SetRelocSym(rIdx, syms.GOT)
+		su.SetRelocAdd(rIdx, int64(ldr.SymGot(targ)))
+		return true
+	}
+
+	// Reread the reloc to incorporate any changes in type above.
+	relocs := ldr.Relocs(s)
+	r = relocs.At(rIdx)
+
+	switch r.Type() {
+	case objabi.R_CALL,
+		objabi.R_PCREL,
+		objabi.R_CALLARM64:
+		if targType != sym.SDYNIMPORT {
+			// nothing to do, the relocation will be laid out in reloc
+			return true
+		}
+		if target.IsExternal() {
+			// External linker will do this relocation.
+			return true
+		}
+		// Internal linking.
+		if r.Add() != 0 {
+			ldr.Errorf(s, "PLT call with non-zero addend (%v)", r.Add())
+		}
+		// Build a PLT entry and change the relocation target to that entry.
+		addpltsym(target, ldr, syms, targ)
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocSym(rIdx, syms.PLT)
+		su.SetRelocAdd(rIdx, int64(ldr.SymPlt(targ)))
+		return true
+
+	case objabi.R_ADDR:
+		if ldr.SymType(s) == sym.STEXT && target.IsElf() {
+			// The code is asking for the address of an external
+			// function. We provide it with the address of the
+			// correspondent GOT symbol.
+			ld.AddGotSym(target, ldr, syms, targ, uint32(elf.R_AARCH64_GLOB_DAT))
+			su := ldr.MakeSymbolUpdater(s)
+			su.SetRelocSym(rIdx, syms.GOT)
+			su.SetRelocAdd(rIdx, r.Add()+int64(ldr.SymGot(targ)))
+			return true
+		}
+
+		// Process dynamic relocations for the data sections.
+		if target.IsPIE() && target.IsInternal() {
+			// When internally linking, generate dynamic relocations
+			// for all typical R_ADDR relocations. The exception
+			// are those R_ADDR that are created as part of generating
+			// the dynamic relocations and must be resolved statically.
+			//
+			// There are three phases relevant to understanding this:
+			//
+			//	dodata()  // we are here
+			//	address() // symbol address assignment
+			//	reloc()   // resolution of static R_ADDR relocs
+			//
+			// At this point symbol addresses have not been
+			// assigned yet (as the final size of the .rela section
+			// will affect the addresses), and so we cannot write
+			// the Elf64_Rela.r_offset now. Instead we delay it
+			// until after the 'address' phase of the linker is
+			// complete. We do this via Addaddrplus, which creates
+			// a new R_ADDR relocation which will be resolved in
+			// the 'reloc' phase.
+			//
+			// These synthetic static R_ADDR relocs must be skipped
+			// now, or else we will be caught in an infinite loop
+			// of generating synthetic relocs for our synthetic
+			// relocs.
+			//
+			// Furthermore, the rela sections contain dynamic
+			// relocations with R_ADDR relocations on
+			// Elf64_Rela.r_offset. This field should contain the
+			// symbol offset as determined by reloc(), not the
+			// final dynamically linked address as a dynamic
+			// relocation would provide.
+			switch ldr.SymName(s) {
+			case ".dynsym", ".rela", ".rela.plt", ".got.plt", ".dynamic":
+				return false
+			}
+		} else {
+			// Either internally linking a static executable,
+			// in which case we can resolve these relocations
+			// statically in the 'reloc' phase, or externally
+			// linking, in which case the relocation will be
+			// prepared in the 'reloc' phase and passed to the
+			// external linker in the 'asmb' phase.
+			if ldr.SymType(s) != sym.SDATA && ldr.SymType(s) != sym.SRODATA {
+				break
+			}
+		}
+
+		if target.IsElf() {
+			// Generate R_AARCH64_RELATIVE relocations for best
+			// efficiency in the dynamic linker.
+			//
+			// As noted above, symbol addresses have not been
+			// assigned yet, so we can't generate the final reloc
+			// entry yet. We ultimately want:
+			//
+			// r_offset = s + r.Off
+			// r_info = R_AARCH64_RELATIVE
+			// r_addend = targ + r.Add
+			//
+			// The dynamic linker will set *offset = base address +
+			// addend.
+			//
+			// AddAddrPlus is used for r_offset and r_addend to
+			// generate new R_ADDR relocations that will update
+			// these fields in the 'reloc' phase.
+			rela := ldr.MakeSymbolUpdater(syms.Rela)
+			rela.AddAddrPlus(target.Arch, s, int64(r.Off()))
+			if r.Siz() == 8 {
+				rela.AddUint64(target.Arch, elf.R_INFO(0, uint32(elf.R_AARCH64_RELATIVE)))
+			} else {
+				ldr.Errorf(s, "unexpected relocation for dynamic symbol %s", ldr.SymName(targ))
+			}
+			rela.AddAddrPlus(target.Arch, targ, int64(r.Add()))
+			// Not mark r done here. So we still apply it statically,
+			// so in the file content we'll also have the right offset
+			// to the relocation target. So it can be examined statically
+			// (e.g. go version).
+			return true
+		}
+
+		if target.IsDarwin() {
+			// Mach-O relocations are a royal pain to lay out.
+			// They use a compact stateful bytecode representation.
+			// Here we record what are needed and encode them later.
+			ld.MachoAddRebase(s, int64(r.Off()))
+			// Not mark r done here. So we still apply it statically,
+			// so in the file content we'll also have the right offset
+			// to the relocation target. So it can be examined statically
+			// (e.g. go version).
+			return true
+		}
+	}
+	return false
+}
+
+func elfreloc1(ctxt *ld.Link, out *ld.OutBuf, ldr *loader.Loader, s loader.Sym, r loader.ExtReloc, ri int, sectoff int64) bool {
+	out.Write64(uint64(sectoff))
+
+	elfsym := ld.ElfSymForReloc(ctxt, r.Xsym)
+	siz := r.Size
+	switch r.Type {
+	default:
+		return false
+	case objabi.R_ADDR, objabi.R_DWARFSECREF:
+		switch siz {
+		case 4:
+			out.Write64(uint64(elf.R_AARCH64_ABS32) | uint64(elfsym)<<32)
+		case 8:
+			out.Write64(uint64(elf.R_AARCH64_ABS64) | uint64(elfsym)<<32)
+		default:
+			return false
+		}
+	case objabi.R_ADDRARM64:
+		// two relocations: R_AARCH64_ADR_PREL_PG_HI21 and R_AARCH64_ADD_ABS_LO12_NC
+		out.Write64(uint64(elf.R_AARCH64_ADR_PREL_PG_HI21) | uint64(elfsym)<<32)
+		out.Write64(uint64(r.Xadd))
+		out.Write64(uint64(sectoff + 4))
+		out.Write64(uint64(elf.R_AARCH64_ADD_ABS_LO12_NC) | uint64(elfsym)<<32)
+	case objabi.R_ARM64_TLS_LE:
+		out.Write64(uint64(elf.R_AARCH64_TLSLE_MOVW_TPREL_G0) | uint64(elfsym)<<32)
+	case objabi.R_ARM64_TLS_IE:
+		out.Write64(uint64(elf.R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21) | uint64(elfsym)<<32)
+		out.Write64(uint64(r.Xadd))
+		out.Write64(uint64(sectoff + 4))
+		out.Write64(uint64(elf.R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC) | uint64(elfsym)<<32)
+	case objabi.R_ARM64_GOTPCREL:
+		out.Write64(uint64(elf.R_AARCH64_ADR_GOT_PAGE) | uint64(elfsym)<<32)
+		out.Write64(uint64(r.Xadd))
+		out.Write64(uint64(sectoff + 4))
+		out.Write64(uint64(elf.R_AARCH64_LD64_GOT_LO12_NC) | uint64(elfsym)<<32)
+	case objabi.R_CALLARM64:
+		if siz != 4 {
+			return false
+		}
+		out.Write64(uint64(elf.R_AARCH64_CALL26) | uint64(elfsym)<<32)
+
+	}
+	out.Write64(uint64(r.Xadd))
+
+	return true
+}
+
+// sign-extends from 24-bit.
+func signext24(x int64) int64 { return x << 40 >> 40 }
+
+func machoreloc1(arch *sys.Arch, out *ld.OutBuf, ldr *loader.Loader, s loader.Sym, r loader.ExtReloc, sectoff int64) bool {
+	var v uint32
+
+	rs := r.Xsym
+	rt := r.Type
+	siz := r.Size
+	xadd := r.Xadd
+
+	if xadd != signext24(xadd) {
+		// If the relocation target would overflow the addend, then target
+		// a linker-manufactured label symbol with a smaller addend instead.
+		label := ldr.Lookup(machoLabelName(ldr, rs, xadd), ldr.SymVersion(rs))
+		if label != 0 {
+			xadd = ldr.SymValue(rs) + xadd - ldr.SymValue(label)
+			rs = label
+		}
+		if xadd != signext24(xadd) {
+			ldr.Errorf(s, "internal error: relocation addend overflow: %s+0x%x", ldr.SymName(rs), xadd)
+		}
+	}
+
+	if ldr.SymType(rs) == sym.SHOSTOBJ || rt == objabi.R_CALLARM64 || rt == objabi.R_ADDRARM64 || rt == objabi.R_ARM64_GOTPCREL {
+		if ldr.SymDynid(rs) < 0 {
+			ldr.Errorf(s, "reloc %d (%s) to non-macho symbol %s type=%d (%s)", rt, sym.RelocName(arch, rt), ldr.SymName(rs), ldr.SymType(rs), ldr.SymType(rs))
+			return false
+		}
+
+		v = uint32(ldr.SymDynid(rs))
+		v |= 1 << 27 // external relocation
+	} else {
+		v = uint32(ldr.SymSect(rs).Extnum)
+		if v == 0 {
+			ldr.Errorf(s, "reloc %d (%s) to symbol %s in non-macho section %s type=%d (%s)", rt, sym.RelocName(arch, rt), ldr.SymName(rs), ldr.SymSect(rs).Name, ldr.SymType(rs), ldr.SymType(rs))
+			return false
+		}
+	}
+
+	switch rt {
+	default:
+		return false
+	case objabi.R_ADDR:
+		v |= ld.MACHO_ARM64_RELOC_UNSIGNED << 28
+	case objabi.R_CALLARM64:
+		if xadd != 0 {
+			ldr.Errorf(s, "ld64 doesn't allow BR26 reloc with non-zero addend: %s+%d", ldr.SymName(rs), xadd)
+		}
+
+		v |= 1 << 24 // pc-relative bit
+		v |= ld.MACHO_ARM64_RELOC_BRANCH26 << 28
+	case objabi.R_ADDRARM64:
+		siz = 4
+		// Two relocation entries: MACHO_ARM64_RELOC_PAGEOFF12 MACHO_ARM64_RELOC_PAGE21
+		// if r.Xadd is non-zero, add two MACHO_ARM64_RELOC_ADDEND.
+		if r.Xadd != 0 {
+			out.Write32(uint32(sectoff + 4))
+			out.Write32((ld.MACHO_ARM64_RELOC_ADDEND << 28) | (2 << 25) | uint32(xadd&0xffffff))
+		}
+		out.Write32(uint32(sectoff + 4))
+		out.Write32(v | (ld.MACHO_ARM64_RELOC_PAGEOFF12 << 28) | (2 << 25))
+		if r.Xadd != 0 {
+			out.Write32(uint32(sectoff))
+			out.Write32((ld.MACHO_ARM64_RELOC_ADDEND << 28) | (2 << 25) | uint32(xadd&0xffffff))
+		}
+		v |= 1 << 24 // pc-relative bit
+		v |= ld.MACHO_ARM64_RELOC_PAGE21 << 28
+	case objabi.R_ARM64_GOTPCREL:
+		siz = 4
+		// Two relocation entries: MACHO_ARM64_RELOC_GOT_LOAD_PAGEOFF12 MACHO_ARM64_RELOC_GOT_LOAD_PAGE21
+		// if r.Xadd is non-zero, add two MACHO_ARM64_RELOC_ADDEND.
+		if r.Xadd != 0 {
+			out.Write32(uint32(sectoff + 4))
+			out.Write32((ld.MACHO_ARM64_RELOC_ADDEND << 28) | (2 << 25) | uint32(xadd&0xffffff))
+		}
+		out.Write32(uint32(sectoff + 4))
+		out.Write32(v | (ld.MACHO_ARM64_RELOC_GOT_LOAD_PAGEOFF12 << 28) | (2 << 25))
+		if r.Xadd != 0 {
+			out.Write32(uint32(sectoff))
+			out.Write32((ld.MACHO_ARM64_RELOC_ADDEND << 28) | (2 << 25) | uint32(xadd&0xffffff))
+		}
+		v |= 1 << 24 // pc-relative bit
+		v |= ld.MACHO_ARM64_RELOC_GOT_LOAD_PAGE21 << 28
+	}
+
+	switch siz {
+	default:
+		return false
+	case 1:
+		v |= 0 << 25
+	case 2:
+		v |= 1 << 25
+	case 4:
+		v |= 2 << 25
+	case 8:
+		v |= 3 << 25
+	}
+
+	out.Write32(uint32(sectoff))
+	out.Write32(v)
+	return true
+}
+
+func archreloc(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, r loader.Reloc, s loader.Sym, val int64) (int64, int, bool) {
+	const noExtReloc = 0
+	const isOk = true
+
+	rs := ldr.ResolveABIAlias(r.Sym())
+
+	if target.IsExternal() {
+		nExtReloc := 0
+		switch rt := r.Type(); rt {
+		default:
+		case objabi.R_ARM64_GOTPCREL,
+			objabi.R_ADDRARM64:
+
+			// set up addend for eventual relocation via outer symbol.
+			rs, off := ld.FoldSubSymbolOffset(ldr, rs)
+			xadd := r.Add() + off
+			rst := ldr.SymType(rs)
+			if rst != sym.SHOSTOBJ && rst != sym.SDYNIMPORT && ldr.SymSect(rs) == nil {
+				ldr.Errorf(s, "missing section for %s", ldr.SymName(rs))
+			}
+
+			nExtReloc = 2 // need two ELF/Mach-O relocations. see elfreloc1/machoreloc1
+			if target.IsDarwin() && xadd != 0 {
+				nExtReloc = 4 // need another two relocations for non-zero addend
+			}
+
+			// Note: ld64 currently has a bug that any non-zero addend for BR26 relocation
+			// will make the linking fail because it thinks the code is not PIC even though
+			// the BR26 relocation should be fully resolved at link time.
+			// That is the reason why the next if block is disabled. When the bug in ld64
+			// is fixed, we can enable this block and also enable duff's device in cmd/7g.
+			if false && target.IsDarwin() {
+				var o0, o1 uint32
+
+				if target.IsBigEndian() {
+					o0 = uint32(val >> 32)
+					o1 = uint32(val)
+				} else {
+					o0 = uint32(val)
+					o1 = uint32(val >> 32)
+				}
+				// Mach-O wants the addend to be encoded in the instruction
+				// Note that although Mach-O supports ARM64_RELOC_ADDEND, it
+				// can only encode 24-bit of signed addend, but the instructions
+				// supports 33-bit of signed addend, so we always encode the
+				// addend in place.
+				o0 |= (uint32((xadd>>12)&3) << 29) | (uint32((xadd>>12>>2)&0x7ffff) << 5)
+				o1 |= uint32(xadd&0xfff) << 10
+
+				// when laid out, the instruction order must always be o1, o2.
+				if target.IsBigEndian() {
+					val = int64(o0)<<32 | int64(o1)
+				} else {
+					val = int64(o1)<<32 | int64(o0)
+				}
+			}
+
+			return val, nExtReloc, isOk
+		case objabi.R_CALLARM64,
+			objabi.R_ARM64_TLS_LE,
+			objabi.R_ARM64_TLS_IE:
+			nExtReloc = 1
+			if rt == objabi.R_ARM64_TLS_IE {
+				nExtReloc = 2 // need two ELF relocations. see elfreloc1
+			}
+			return val, nExtReloc, isOk
+		}
+	}
+
+	switch r.Type() {
+	case objabi.R_ADDRARM64:
+		t := ldr.SymAddr(rs) + r.Add() - ((ldr.SymValue(s) + int64(r.Off())) &^ 0xfff)
+		if t >= 1<<32 || t < -1<<32 {
+			ldr.Errorf(s, "program too large, address relocation distance = %d", t)
+		}
+
+		var o0, o1 uint32
+
+		if target.IsBigEndian() {
+			o0 = uint32(val >> 32)
+			o1 = uint32(val)
+		} else {
+			o0 = uint32(val)
+			o1 = uint32(val >> 32)
+		}
+
+		o0 |= (uint32((t>>12)&3) << 29) | (uint32((t>>12>>2)&0x7ffff) << 5)
+		o1 |= uint32(t&0xfff) << 10
+
+		// when laid out, the instruction order must always be o1, o2.
+		if target.IsBigEndian() {
+			return int64(o0)<<32 | int64(o1), noExtReloc, true
+		}
+		return int64(o1)<<32 | int64(o0), noExtReloc, true
+
+	case objabi.R_ARM64_TLS_LE:
+		if target.IsDarwin() {
+			ldr.Errorf(s, "TLS reloc on unsupported OS %v", target.HeadType)
+		}
+		// The TCB is two pointers. This is not documented anywhere, but is
+		// de facto part of the ABI.
+		v := ldr.SymValue(rs) + int64(2*target.Arch.PtrSize)
+		if v < 0 || v >= 32678 {
+			ldr.Errorf(s, "TLS offset out of range %d", v)
+		}
+		return val | (v << 5), noExtReloc, true
+
+	case objabi.R_ARM64_TLS_IE:
+		if target.IsPIE() && target.IsElf() {
+			// We are linking the final executable, so we
+			// can optimize any TLS IE relocation to LE.
+
+			if !target.IsLinux() {
+				ldr.Errorf(s, "TLS reloc on unsupported OS %v", target.HeadType)
+			}
+
+			// The TCB is two pointers. This is not documented anywhere, but is
+			// de facto part of the ABI.
+			v := ldr.SymAddr(rs) + int64(2*target.Arch.PtrSize) + r.Add()
+			if v < 0 || v >= 32678 {
+				ldr.Errorf(s, "TLS offset out of range %d", v)
+			}
+
+			var o0, o1 uint32
+			if target.IsBigEndian() {
+				o0 = uint32(val >> 32)
+				o1 = uint32(val)
+			} else {
+				o0 = uint32(val)
+				o1 = uint32(val >> 32)
+			}
+
+			// R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21
+			// turn ADRP to MOVZ
+			o0 = 0xd2a00000 | uint32(o0&0x1f) | (uint32((v>>16)&0xffff) << 5)
+			// R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC
+			// turn LD64 to MOVK
+			if v&3 != 0 {
+				ldr.Errorf(s, "invalid address: %x for relocation type: R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC", v)
+			}
+			o1 = 0xf2800000 | uint32(o1&0x1f) | (uint32(v&0xffff) << 5)
+
+			// when laid out, the instruction order must always be o0, o1.
+			if target.IsBigEndian() {
+				return int64(o0)<<32 | int64(o1), noExtReloc, isOk
+			}
+			return int64(o1)<<32 | int64(o0), noExtReloc, isOk
+		} else {
+			log.Fatalf("cannot handle R_ARM64_TLS_IE (sym %s) when linking internally", ldr.SymName(s))
+		}
+
+	case objabi.R_CALLARM64:
+		var t int64
+		if ldr.SymType(rs) == sym.SDYNIMPORT {
+			t = (ldr.SymAddr(syms.PLT) + r.Add()) - (ldr.SymValue(s) + int64(r.Off()))
+		} else {
+			t = (ldr.SymAddr(rs) + r.Add()) - (ldr.SymValue(s) + int64(r.Off()))
+		}
+		if t >= 1<<27 || t < -1<<27 {
+			ldr.Errorf(s, "program too large, call relocation distance = %d", t)
+		}
+		return val | ((t >> 2) & 0x03ffffff), noExtReloc, true
+
+	case objabi.R_ARM64_GOT:
+		if (val>>24)&0x9f == 0x90 {
+			// R_AARCH64_ADR_GOT_PAGE
+			// patch instruction: adrp
+			t := ldr.SymAddr(rs) + r.Add() - ((ldr.SymValue(s) + int64(r.Off())) &^ 0xfff)
+			if t >= 1<<32 || t < -1<<32 {
+				ldr.Errorf(s, "program too large, address relocation distance = %d", t)
+			}
+			var o0 uint32
+			o0 |= (uint32((t>>12)&3) << 29) | (uint32((t>>12>>2)&0x7ffff) << 5)
+			return val | int64(o0), noExtReloc, isOk
+		} else if val>>24 == 0xf9 {
+			// R_AARCH64_LD64_GOT_LO12_NC
+			// patch instruction: ldr
+			t := ldr.SymAddr(rs) + r.Add() - ((ldr.SymValue(s) + int64(r.Off())) &^ 0xfff)
+			if t&7 != 0 {
+				ldr.Errorf(s, "invalid address: %x for relocation type: R_AARCH64_LD64_GOT_LO12_NC", t)
+			}
+			var o1 uint32
+			o1 |= uint32(t&0xfff) << (10 - 3)
+			return val | int64(uint64(o1)), noExtReloc, isOk
+		} else {
+			ldr.Errorf(s, "unsupported instruction for %x R_GOTARM64", val)
+		}
+
+	case objabi.R_ARM64_PCREL:
+		if (val>>24)&0x9f == 0x90 {
+			// R_AARCH64_ADR_PREL_PG_HI21
+			// patch instruction: adrp
+			t := ldr.SymAddr(rs) + r.Add() - ((ldr.SymValue(s) + int64(r.Off())) &^ 0xfff)
+			if t >= 1<<32 || t < -1<<32 {
+				ldr.Errorf(s, "program too large, address relocation distance = %d", t)
+			}
+			o0 := (uint32((t>>12)&3) << 29) | (uint32((t>>12>>2)&0x7ffff) << 5)
+			return val | int64(o0), noExtReloc, isOk
+		} else if (val>>24)&0x9f == 0x91 {
+			// ELF R_AARCH64_ADD_ABS_LO12_NC or Mach-O ARM64_RELOC_PAGEOFF12
+			// patch instruction: add
+			t := ldr.SymAddr(rs) + r.Add() - ((ldr.SymValue(s) + int64(r.Off())) &^ 0xfff)
+			o1 := uint32(t&0xfff) << 10
+			return val | int64(o1), noExtReloc, isOk
+		} else if (val>>24)&0x3b == 0x39 {
+			// Mach-O ARM64_RELOC_PAGEOFF12
+			// patch ldr/str(b/h/w/d/q) (integer or vector) instructions, which have different scaling factors.
+			// Mach-O uses same relocation type for them.
+			shift := uint32(val) >> 30
+			if shift == 0 && (val>>20)&0x048 == 0x048 { // 128-bit vector load
+				shift = 4
+			}
+			t := ldr.SymAddr(rs) + r.Add() - ((ldr.SymValue(s) + int64(r.Off())) &^ 0xfff)
+			if t&(1<<shift-1) != 0 {
+				ldr.Errorf(s, "invalid address: %x for relocation type: ARM64_RELOC_PAGEOFF12", t)
+			}
+			o1 := (uint32(t&0xfff) >> shift) << 10
+			return val | int64(o1), noExtReloc, isOk
+		} else {
+			ldr.Errorf(s, "unsupported instruction for %x R_ARM64_PCREL", val)
+		}
+
+	case objabi.R_ARM64_LDST8:
+		t := ldr.SymAddr(rs) + r.Add() - ((ldr.SymValue(s) + int64(r.Off())) &^ 0xfff)
+		o0 := uint32(t&0xfff) << 10
+		return val | int64(o0), noExtReloc, true
+
+	case objabi.R_ARM64_LDST16:
+		t := ldr.SymAddr(rs) + r.Add() - ((ldr.SymValue(s) + int64(r.Off())) &^ 0xfff)
+		if t&1 != 0 {
+			ldr.Errorf(s, "invalid address: %x for relocation type: R_AARCH64_LDST16_ABS_LO12_NC", t)
+		}
+		o0 := (uint32(t&0xfff) >> 1) << 10
+		return val | int64(o0), noExtReloc, true
+
+	case objabi.R_ARM64_LDST32:
+		t := ldr.SymAddr(rs) + r.Add() - ((ldr.SymValue(s) + int64(r.Off())) &^ 0xfff)
+		if t&3 != 0 {
+			ldr.Errorf(s, "invalid address: %x for relocation type: R_AARCH64_LDST32_ABS_LO12_NC", t)
+		}
+		o0 := (uint32(t&0xfff) >> 2) << 10
+		return val | int64(o0), noExtReloc, true
+
+	case objabi.R_ARM64_LDST64:
+		t := ldr.SymAddr(rs) + r.Add() - ((ldr.SymValue(s) + int64(r.Off())) &^ 0xfff)
+		if t&7 != 0 {
+			ldr.Errorf(s, "invalid address: %x for relocation type: R_AARCH64_LDST64_ABS_LO12_NC", t)
+		}
+		o0 := (uint32(t&0xfff) >> 3) << 10
+		return val | int64(o0), noExtReloc, true
+
+	case objabi.R_ARM64_LDST128:
+		t := ldr.SymAddr(rs) + r.Add() - ((ldr.SymValue(s) + int64(r.Off())) &^ 0xfff)
+		if t&15 != 0 {
+			ldr.Errorf(s, "invalid address: %x for relocation type: R_AARCH64_LDST128_ABS_LO12_NC", t)
+		}
+		o0 := (uint32(t&0xfff) >> 4) << 10
+		return val | int64(o0), noExtReloc, true
+	}
+
+	return val, 0, false
+}
+
+func archrelocvariant(*ld.Target, *loader.Loader, loader.Reloc, sym.RelocVariant, loader.Sym, int64) int64 {
+	log.Fatalf("unexpected relocation variant")
+	return -1
+}
+
+func extreloc(target *ld.Target, ldr *loader.Loader, r loader.Reloc, s loader.Sym) (loader.ExtReloc, bool) {
+	switch rt := r.Type(); rt {
+	case objabi.R_ARM64_GOTPCREL,
+		objabi.R_ADDRARM64:
+		rr := ld.ExtrelocViaOuterSym(ldr, r, s)
+
+		// Note: ld64 currently has a bug that any non-zero addend for BR26 relocation
+		// will make the linking fail because it thinks the code is not PIC even though
+		// the BR26 relocation should be fully resolved at link time.
+		// That is the reason why the next if block is disabled. When the bug in ld64
+		// is fixed, we can enable this block and also enable duff's device in cmd/7g.
+		if false && target.IsDarwin() {
+			// Mach-O wants the addend to be encoded in the instruction
+			// Note that although Mach-O supports ARM64_RELOC_ADDEND, it
+			// can only encode 24-bit of signed addend, but the instructions
+			// supports 33-bit of signed addend, so we always encode the
+			// addend in place.
+			rr.Xadd = 0
+		}
+		return rr, true
+	case objabi.R_CALLARM64,
+		objabi.R_ARM64_TLS_LE,
+		objabi.R_ARM64_TLS_IE:
+		return ld.ExtrelocSimple(ldr, r), true
+	}
+	return loader.ExtReloc{}, false
+}
+
+func elfsetupplt(ctxt *ld.Link, plt, gotplt *loader.SymbolBuilder, dynamic loader.Sym) {
+	if plt.Size() == 0 {
+		// stp     x16, x30, [sp, #-16]!
+		// identifying information
+		plt.AddUint32(ctxt.Arch, 0xa9bf7bf0)
+
+		// the following two instructions (adrp + ldr) load *got[2] into x17
+		// adrp    x16, &got[0]
+		plt.AddSymRef(ctxt.Arch, gotplt.Sym(), 16, objabi.R_ARM64_GOT, 4)
+		plt.SetUint32(ctxt.Arch, plt.Size()-4, 0x90000010)
+
+		// <imm> is the offset value of &got[2] to &got[0], the same below
+		// ldr     x17, [x16, <imm>]
+		plt.AddSymRef(ctxt.Arch, gotplt.Sym(), 16, objabi.R_ARM64_GOT, 4)
+		plt.SetUint32(ctxt.Arch, plt.Size()-4, 0xf9400211)
+
+		// add     x16, x16, <imm>
+		plt.AddSymRef(ctxt.Arch, gotplt.Sym(), 16, objabi.R_ARM64_PCREL, 4)
+		plt.SetUint32(ctxt.Arch, plt.Size()-4, 0x91000210)
+
+		// br      x17
+		plt.AddUint32(ctxt.Arch, 0xd61f0220)
+
+		// 3 nop for place holder
+		plt.AddUint32(ctxt.Arch, 0xd503201f)
+		plt.AddUint32(ctxt.Arch, 0xd503201f)
+		plt.AddUint32(ctxt.Arch, 0xd503201f)
+
+		// check gotplt.size == 0
+		if gotplt.Size() != 0 {
+			ctxt.Errorf(gotplt.Sym(), "got.plt is not empty at the very beginning")
+		}
+		gotplt.AddAddrPlus(ctxt.Arch, dynamic, 0)
+
+		gotplt.AddUint64(ctxt.Arch, 0)
+		gotplt.AddUint64(ctxt.Arch, 0)
+	}
+}
+
+func addpltsym(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loader.Sym) {
+	if ldr.SymPlt(s) >= 0 {
+		return
+	}
+
+	ld.Adddynsym(ldr, target, syms, s)
+
+	if target.IsElf() {
+		plt := ldr.MakeSymbolUpdater(syms.PLT)
+		gotplt := ldr.MakeSymbolUpdater(syms.GOTPLT)
+		rela := ldr.MakeSymbolUpdater(syms.RelaPLT)
+		if plt.Size() == 0 {
+			panic("plt is not set up")
+		}
+
+		// adrp    x16, &got.plt[0]
+		plt.AddAddrPlus4(target.Arch, gotplt.Sym(), gotplt.Size())
+		plt.SetUint32(target.Arch, plt.Size()-4, 0x90000010)
+		relocs := plt.Relocs()
+		plt.SetRelocType(relocs.Count()-1, objabi.R_ARM64_GOT)
+
+		// <offset> is the offset value of &got.plt[n] to &got.plt[0]
+		// ldr     x17, [x16, <offset>]
+		plt.AddAddrPlus4(target.Arch, gotplt.Sym(), gotplt.Size())
+		plt.SetUint32(target.Arch, plt.Size()-4, 0xf9400211)
+		relocs = plt.Relocs()
+		plt.SetRelocType(relocs.Count()-1, objabi.R_ARM64_GOT)
+
+		// add     x16, x16, <offset>
+		plt.AddAddrPlus4(target.Arch, gotplt.Sym(), gotplt.Size())
+		plt.SetUint32(target.Arch, plt.Size()-4, 0x91000210)
+		relocs = plt.Relocs()
+		plt.SetRelocType(relocs.Count()-1, objabi.R_ARM64_PCREL)
+
+		// br      x17
+		plt.AddUint32(target.Arch, 0xd61f0220)
+
+		// add to got.plt: pointer to plt[0]
+		gotplt.AddAddrPlus(target.Arch, plt.Sym(), 0)
+
+		// rela
+		rela.AddAddrPlus(target.Arch, gotplt.Sym(), gotplt.Size()-8)
+		sDynid := ldr.SymDynid(s)
+
+		rela.AddUint64(target.Arch, elf.R_INFO(uint32(sDynid), uint32(elf.R_AARCH64_JUMP_SLOT)))
+		rela.AddUint64(target.Arch, 0)
+
+		ldr.SetPlt(s, int32(plt.Size()-16))
+	} else if target.IsDarwin() {
+		ld.AddGotSym(target, ldr, syms, s, 0)
+
+		sDynid := ldr.SymDynid(s)
+		lep := ldr.MakeSymbolUpdater(syms.LinkEditPLT)
+		lep.AddUint32(target.Arch, uint32(sDynid))
+
+		plt := ldr.MakeSymbolUpdater(syms.PLT)
+		ldr.SetPlt(s, int32(plt.Size()))
+
+		// adrp x16, GOT
+		plt.AddUint32(target.Arch, 0x90000010)
+		r, _ := plt.AddRel(objabi.R_ARM64_GOT)
+		r.SetOff(int32(plt.Size() - 4))
+		r.SetSiz(4)
+		r.SetSym(syms.GOT)
+		r.SetAdd(int64(ldr.SymGot(s)))
+
+		// ldr x17, [x16, <offset>]
+		plt.AddUint32(target.Arch, 0xf9400211)
+		r, _ = plt.AddRel(objabi.R_ARM64_GOT)
+		r.SetOff(int32(plt.Size() - 4))
+		r.SetSiz(4)
+		r.SetSym(syms.GOT)
+		r.SetAdd(int64(ldr.SymGot(s)))
+
+		// br x17
+		plt.AddUint32(target.Arch, 0xd61f0220)
+	} else {
+		ldr.Errorf(s, "addpltsym: unsupported binary format")
+	}
+}
+
+const machoRelocLimit = 1 << 23
+
+func gensymlate(ctxt *ld.Link, ldr *loader.Loader) {
+	// When external linking on darwin, Mach-O relocation has only signed 24-bit
+	// addend. For large symbols, we generate "label" symbols in the middle, so
+	// that relocations can target them with smaller addends.
+	if !ctxt.IsDarwin() || !ctxt.IsExternal() {
+		return
+	}
+
+	big := false
+	for _, seg := range ld.Segments {
+		if seg.Length >= machoRelocLimit {
+			big = true
+			break
+		}
+	}
+	if !big {
+		return // skip work if nothing big
+	}
+
+	// addLabelSyms adds "label" symbols at s+machoRelocLimit, s+2*machoRelocLimit, etc.
+	addLabelSyms := func(s loader.Sym, sz int64) {
+		v := ldr.SymValue(s)
+		for off := int64(machoRelocLimit); off < sz; off += machoRelocLimit {
+			p := ldr.LookupOrCreateSym(machoLabelName(ldr, s, off), ldr.SymVersion(s))
+			ldr.SetAttrReachable(p, true)
+			ldr.SetSymValue(p, v+off)
+			ldr.SetSymSect(p, ldr.SymSect(s))
+			ld.AddMachoSym(ldr, p)
+			//fmt.Printf("gensymlate %s %x\n", ldr.SymName(p), ldr.SymValue(p))
+		}
+	}
+
+	for s, n := loader.Sym(1), loader.Sym(ldr.NSym()); s < n; s++ {
+		if !ldr.AttrReachable(s) {
+			continue
+		}
+		if ldr.SymType(s) == sym.STEXT {
+			continue // we don't target the middle of a function
+		}
+		sz := ldr.SymSize(s)
+		if sz <= machoRelocLimit {
+			continue
+		}
+		addLabelSyms(s, sz)
+	}
+
+	// Also for carrier symbols (for which SymSize is 0)
+	for _, ss := range ld.CarrierSymByType {
+		if ss.Sym != 0 && ss.Size > machoRelocLimit {
+			addLabelSyms(ss.Sym, ss.Size)
+		}
+	}
+}
+
+// machoLabelName returns the name of the "label" symbol used for a
+// relocation targeting s+off. The label symbols is used on darwin
+// when external linking, so that the addend fits in a Mach-O relocation.
+func machoLabelName(ldr *loader.Loader, s loader.Sym, off int64) string {
+	return fmt.Sprintf("%s.%d", ldr.SymExtname(s), off/machoRelocLimit)
+}