[dev.link] cmd/link: remove some x86/Darwin code

Found while looking at common code between architectures.

Recreation of CL 234680 which was accidentally on master.

Change-Id: Ib8fac3168916e8e64b2bc65fd3830c5856d77c5e
Reviewed-on: https://go-review.googlesource.com/c/go/+/234682
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>

diff --git a/src/cmd/link/internal/x86/asm.go b/src/cmd/link/internal/x86/asm.go
index 296184e3237cc58b3788e5f75fb471be35133e59..ecd5058f4c7d46fe321ef509cf7ac66447b9cc67 100644 (file)
--- a/src/cmd/link/internal/x86/asm.go
+++ b/src/cmd/link/internal/x86/asm.go
@@ -310,31 +310,6 @@ func adddynrel(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loade
                        su.SetRelocSym(rIdx, 0)
                        return true
                }
-
-               if target.IsDarwin() && ldr.SymSize(s) == int64(target.Arch.PtrSize) && r.Off() == 0 {
-                       // Mach-O relocations are a royal pain to lay out.
-                       // They use a compact stateful bytecode representation
-                       // that is too much bother to deal with.
-                       // Instead, interpret the C declaration
-                       //      void *_Cvar_stderr = &stderr;
-                       // as making _Cvar_stderr the name of a GOT entry
-                       // for stderr. This is separate from the usual GOT entry,
-                       // just in case the C code assigns to the variable,
-                       // and of course it only works for single pointers,
-                       // but we only need to support cgo and that's all it needs.
-                       ld.Adddynsym(ldr, target, syms, targ)
-
-                       got := ldr.MakeSymbolUpdater(syms.GOT)
-                       su := ldr.MakeSymbolUpdater(s)
-                       su.SetType(got.Type())
-                       got.PrependSub(s)
-                       su.SetValue(got.Size())
-                       got.AddUint32(target.Arch, 0)
-                       leg := ldr.MakeSymbolUpdater(syms.LinkEditGOT)
-                       leg.AddUint32(target.Arch, uint32(ldr.SymDynid(targ)))
-                       su.SetRelocType(rIdx, objabi.ElfRelocOffset) // ignore during relocsym
-                       return true
-               }
        }
 
        return false
@@ -512,23 +487,6 @@ func addpltsym(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loade
                rel.AddUint32(target.Arch, ld.ELF32_R_INFO(uint32(sDynid), uint32(elf.R_386_JMP_SLOT)))
 
                ldr.SetPlt(s, int32(plt.Size()-16))
-       } else if target.IsDarwin() {
-               // Same laziness as in 6l.
-
-               plt := ldr.MakeSymbolUpdater(syms.PLT)
-
-               addgotsym(target, ldr, syms, s)
-
-               sDynid := ldr.SymDynid(s)
-               lep := ldr.MakeSymbolUpdater(syms.LinkEditPLT)
-               lep.AddUint32(target.Arch, uint32(sDynid))
-
-               // jmpq *got+size(IP)
-               ldr.SetPlt(s, int32(plt.Size()))
-
-               plt.AddUint8(0xff)
-               plt.AddUint8(0x25)
-               plt.AddAddrPlus(target.Arch, syms.GOT, int64(ldr.SymGot(s)))
        } else {
                ldr.Errorf(s, "addpltsym: unsupported binary format")
        }
@@ -548,9 +506,6 @@ func addgotsym(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loade
                rel := ldr.MakeSymbolUpdater(syms.Rel)
                rel.AddAddrPlus(target.Arch, got.Sym(), int64(ldr.SymGot(s)))
                rel.AddUint32(target.Arch, ld.ELF32_R_INFO(uint32(ldr.SymDynid(s)), uint32(elf.R_386_GLOB_DAT)))
-       } else if target.IsDarwin() {
-               leg := ldr.MakeSymbolUpdater(syms.LinkEditGOT)
-               leg.AddUint32(target.Arch, uint32(ldr.SymDynid(s)))
        } else {
                ldr.Errorf(s, "addgotsym: unsupported binary format")
        }