cmd/link: refactor ELF hooks into ELFArch struct

This is a pure cleanup to bring the ELF hooks together.

Change-Id: I01d5227c70f30e4a659dcd7904e7c247266e95b1
Reviewed-on: https://go-review.googlesource.com/c/go/+/463981
Auto-Submit: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Joel Sing <joel@sing.id.au>

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

@@ -55,22 +55,25 @@ func Init() (*sys.Arch, ld.Arch) {
 		Archinit:         archinit,
 		Archreloc:        archreloc,
 		Archrelocvariant: archrelocvariant,
-		Elfreloc1:        elfreloc1,
-		ElfrelocSize:     24,
-		Elfsetupplt:      elfsetupplt,
 		Gentext:          gentext,
 		Machoreloc1:      machoreloc1,
 		MachorelocSize:   8,
 		PEreloc1:         pereloc1,
 		TLSIEtoLE:        tlsIEtoLE,
 
-		Linuxdynld:     "/lib64/ld-linux-x86-64.so.2",
+		ELF: ld.ELFArch{
-		LinuxdynldMusl: "/lib/ld-musl-x86_64.so.1",
+			Linuxdynld:     "/lib64/ld-linux-x86-64.so.2",
-		Freebsddynld:   "/libexec/ld-elf.so.1",
+			LinuxdynldMusl: "/lib/ld-musl-x86_64.so.1",
-		Openbsddynld:   "/usr/libexec/ld.so",
+			Freebsddynld:   "/libexec/ld-elf.so.1",
-		Netbsddynld:    "/libexec/ld.elf_so",
+			Openbsddynld:   "/usr/libexec/ld.so",
-		Dragonflydynld: "/usr/libexec/ld-elf.so.2",
+			Netbsddynld:    "/libexec/ld.elf_so",
-		Solarisdynld:   "/lib/amd64/ld.so.1",
+			Dragonflydynld: "/usr/libexec/ld-elf.so.2",
+			Solarisdynld:   "/lib/amd64/ld.so.1",
+
+			Elfreloc1:    elfreloc1,
+			ElfrelocSize: 24,
+			Elfsetupplt:  elfsetupplt,
+		},
 	}
 
 	return arch, theArch

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

@@ -55,20 +55,23 @@ func Init() (*sys.Arch, ld.Arch) {
 		Archrelocvariant: archrelocvariant,
 		Extreloc:         extreloc,
 		Trampoline:       trampoline,
-		Elfreloc1:        elfreloc1,
-		ElfrelocSize:     8,
-		Elfsetupplt:      elfsetupplt,
 		Gentext:          gentext,
 		Machoreloc1:      machoreloc1,
 		PEreloc1:         pereloc1,
 
-		Linuxdynld:     "/lib/ld-linux.so.3", // 2 for OABI, 3 for EABI
+		ELF: ld.ELFArch{
-		LinuxdynldMusl: "/lib/ld-musl-arm.so.1",
+			Linuxdynld:     "/lib/ld-linux.so.3", // 2 for OABI, 3 for EABI
-		Freebsddynld:   "/usr/libexec/ld-elf.so.1",
+			LinuxdynldMusl: "/lib/ld-musl-arm.so.1",
-		Openbsddynld:   "/usr/libexec/ld.so",
+			Freebsddynld:   "/usr/libexec/ld-elf.so.1",
-		Netbsddynld:    "/libexec/ld.elf_so",
+			Openbsddynld:   "/usr/libexec/ld.so",
-		Dragonflydynld: "XXX",
+			Netbsddynld:    "/libexec/ld.elf_so",
-		Solarisdynld:   "XXX",
+			Dragonflydynld: "XXX",
+			Solarisdynld:   "XXX",
+
+			Elfreloc1:    elfreloc1,
+			ElfrelocSize: 8,
+			Elfsetupplt:  elfsetupplt,
+		},
 	}
 
 	return arch, theArch

src/cmd/link/internal/arm64/obj.go

@@ -52,9 +52,6 @@ func Init() (*sys.Arch, ld.Arch) {
 		Archreloc:        archreloc,
 		Archrelocvariant: archrelocvariant,
 		Extreloc:         extreloc,
-		Elfreloc1:        elfreloc1,
-		ElfrelocSize:     24,
-		Elfsetupplt:      elfsetupplt,
 		Gentext:          gentext,
 		GenSymsLate:      gensymlate,
 		Machoreloc1:      machoreloc1,
@@ -62,15 +59,21 @@ func Init() (*sys.Arch, ld.Arch) {
 		PEreloc1:         pereloc1,
 		Trampoline:       trampoline,
 
-		Androiddynld:   "/system/bin/linker64",
+		ELF: ld.ELFArch{
-		Linuxdynld:     "/lib/ld-linux-aarch64.so.1",
+			Androiddynld:   "/system/bin/linker64",
-		LinuxdynldMusl: "/lib/ld-musl-aarch64.so.1",
+			Linuxdynld:     "/lib/ld-linux-aarch64.so.1",
+			LinuxdynldMusl: "/lib/ld-musl-aarch64.so.1",
 
-		Freebsddynld:   "/usr/libexec/ld-elf.so.1",
+			Freebsddynld:   "/usr/libexec/ld-elf.so.1",
-		Openbsddynld:   "/usr/libexec/ld.so",
+			Openbsddynld:   "/usr/libexec/ld.so",
-		Netbsddynld:    "/libexec/ld.elf_so",
+			Netbsddynld:    "/libexec/ld.elf_so",
-		Dragonflydynld: "XXX",
+			Dragonflydynld: "XXX",
-		Solarisdynld:   "XXX",
+			Solarisdynld:   "XXX",
+
+			Elfreloc1:    elfreloc1,
+			ElfrelocSize: 24,
+			Elfsetupplt:  elfsetupplt,
+		},
 	}
 
 	return arch, theArch

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

@@ -191,6 +191,26 @@ var (
 	interp string
 )
 
+// ELFArch includes target-specific hooks for ELF targets.
+// This is initialized by the target-specific Init function
+// called by the linker's main function in cmd/link/main.go.
+type ELFArch struct {
+	// TODO: Document these fields.
+
+	Androiddynld   string
+	Linuxdynld     string
+	LinuxdynldMusl string
+	Freebsddynld   string
+	Netbsddynld    string
+	Openbsddynld   string
+	Dragonflydynld string
+	Solarisdynld   string
+
+	Elfreloc1    func(*Link, *OutBuf, *loader.Loader, loader.Sym, loader.ExtReloc, int, int64) bool
+	ElfrelocSize uint32 // size of an ELF relocation record, must match Elfreloc1.
+	Elfsetupplt  func(ctxt *Link, plt, gotplt *loader.SymbolBuilder, dynamic loader.Sym)
+}
+
 type Elfstring struct {
 	s   string
 	off int
@@ -1284,7 +1304,7 @@ func elfrelocsect(ctxt *Link, out *OutBuf, sect *sym.Section, syms []loader.Sym)
 			if !ldr.AttrReachable(rr.Xsym) {
 				ldr.Errorf(s, "unreachable reloc %d (%s) target %v", r.Type(), sym.RelocName(ctxt.Arch, r.Type()), ldr.SymName(rr.Xsym))
 			}
-			if !thearch.Elfreloc1(ctxt, out, ldr, s, rr, ri, int64(uint64(ldr.SymValue(s)+int64(r.Off()))-sect.Vaddr)) {
+			if !thearch.ELF.Elfreloc1(ctxt, out, ldr, s, rr, ri, int64(uint64(ldr.SymValue(s)+int64(r.Off()))-sect.Vaddr)) {
 				ldr.Errorf(s, "unsupported obj reloc %d (%s)/%d to %s", r.Type(), sym.RelocName(ctxt.Arch, r.Type()), r.Siz(), ldr.SymName(r.Sym()))
 			}
 		}
@@ -1301,7 +1321,7 @@ func elfEmitReloc(ctxt *Link) {
 		ctxt.Out.Write8(0)
 	}
 
-	sizeExtRelocs(ctxt, thearch.ElfrelocSize)
+	sizeExtRelocs(ctxt, thearch.ELF.ElfrelocSize)
 	relocSect, wg := relocSectFn(ctxt, elfrelocsect)
 
 	for _, sect := range Segtext.Sections {
@@ -1549,7 +1569,7 @@ func (ctxt *Link) doelf() {
 			// S390X uses .got instead of .got.plt
 			gotplt = got
 		}
-		thearch.Elfsetupplt(ctxt, plt, gotplt, dynamic.Sym())
+		thearch.ELF.Elfsetupplt(ctxt, plt, gotplt, dynamic.Sym())
 
 		/*
 		 * .dynamic table
@@ -1846,17 +1866,17 @@ func asmbElf(ctxt *Link) {
 			switch ctxt.HeadType {
 			case objabi.Hlinux:
 				if buildcfg.GOOS == "android" {
-					interpreter = thearch.Androiddynld
+					interpreter = thearch.ELF.Androiddynld
 					if interpreter == "" {
 						Exitf("ELF interpreter not set")
 					}
 				} else {
-					interpreter = thearch.Linuxdynld
+					interpreter = thearch.ELF.Linuxdynld
 					// If interpreter does not exist, try musl instead.
 					// This lets the same cmd/link binary work on
 					// both glibc-based and musl-based systems.
 					if _, err := os.Stat(interpreter); err != nil {
-						if musl := thearch.LinuxdynldMusl; musl != "" {
+						if musl := thearch.ELF.LinuxdynldMusl; musl != "" {
 							if _, err := os.Stat(musl); err == nil {
 								interpreter = musl
 							}
@@ -1865,19 +1885,19 @@ func asmbElf(ctxt *Link) {
 				}
 
 			case objabi.Hfreebsd:
-				interpreter = thearch.Freebsddynld
+				interpreter = thearch.ELF.Freebsddynld
 
 			case objabi.Hnetbsd:
-				interpreter = thearch.Netbsddynld
+				interpreter = thearch.ELF.Netbsddynld
 
 			case objabi.Hopenbsd:
-				interpreter = thearch.Openbsddynld
+				interpreter = thearch.ELF.Openbsddynld
 
 			case objabi.Hdragonfly:
-				interpreter = thearch.Dragonflydynld
+				interpreter = thearch.ELF.Dragonflydynld
 
 			case objabi.Hsolaris:
-				interpreter = thearch.Solarisdynld
+				interpreter = thearch.ELF.Solarisdynld
 			}
 		}
 

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

@@ -181,15 +181,6 @@ type Arch struct {
 	// We leave some room for extra stuff like PLT stubs.
 	TrampLimit uint64
 
-	Androiddynld   string
-	Linuxdynld     string
-	LinuxdynldMusl string
-	Freebsddynld   string
-	Netbsddynld    string
-	Openbsddynld   string
-	Dragonflydynld string
-	Solarisdynld   string
-
 	// Empty spaces between codeblocks will be padded with this value.
 	// For example an architecture might want to pad with a trap instruction to
 	// catch wayward programs. Architectures that do not define a padding value
@@ -244,9 +235,6 @@ type Arch struct {
 	// needed.
 	Extreloc func(*Target, *loader.Loader, loader.Reloc, loader.Sym) (loader.ExtReloc, bool)
 
-	Elfreloc1      func(*Link, *OutBuf, *loader.Loader, loader.Sym, loader.ExtReloc, int, int64) bool
-	ElfrelocSize   uint32 // size of an ELF relocation record, must match Elfreloc1.
-	Elfsetupplt    func(ctxt *Link, plt, gotplt *loader.SymbolBuilder, dynamic loader.Sym)
 	Gentext        func(*Link, *loader.Loader) // Generate text before addressing has been performed.
 	Machoreloc1    func(*sys.Arch, *OutBuf, *loader.Loader, loader.Sym, loader.ExtReloc, int64) bool
 	MachorelocSize uint32 // size of an Mach-O relocation record, must match Machoreloc1.
@@ -267,6 +255,9 @@ type Arch struct {
 
 	// optional override for assignAddress
 	AssignAddress func(ldr *loader.Loader, sect *sym.Section, n int, s loader.Sym, va uint64, isTramp bool) (*sym.Section, int, uint64)
+
+	// ELF specific information.
+	ELF ELFArch
 }
 
 var (

src/cmd/link/internal/loong64/obj.go

@@ -24,19 +24,22 @@ func Init() (*sys.Arch, ld.Arch) {
 		Archreloc:        archreloc,
 		Archrelocvariant: archrelocvariant,
 		Extreloc:         extreloc,
-		Elfreloc1:        elfreloc1,
-		ElfrelocSize:     24,
-		Elfsetupplt:      elfsetupplt,
 		Machoreloc1:      machoreloc1,
 		Gentext:          gentext,
 
-		Linuxdynld:     "/lib64/ld.so.1",
+		ELF: ld.ELFArch{
-		LinuxdynldMusl: "/lib64/ld-musl-loongarch.so.1",
+			Linuxdynld:     "/lib64/ld.so.1",
-		Freebsddynld:   "XXX",
+			LinuxdynldMusl: "/lib64/ld-musl-loongarch.so.1",
-		Openbsddynld:   "XXX",
+			Freebsddynld:   "XXX",
-		Netbsddynld:    "XXX",
+			Openbsddynld:   "XXX",
-		Dragonflydynld: "XXX",
+			Netbsddynld:    "XXX",
-		Solarisdynld:   "XXX",
+			Dragonflydynld: "XXX",
+			Solarisdynld:   "XXX",
+
+			Elfreloc1:    elfreloc1,
+			ElfrelocSize: 24,
+			Elfsetupplt:  elfsetupplt,
+		},
 	}
 
 	return arch, theArch

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

@@ -56,20 +56,23 @@ func Init() (*sys.Arch, ld.Arch) {
 		Archreloc:        archreloc,
 		Archrelocvariant: archrelocvariant,
 		Extreloc:         extreloc,
-		Elfreloc1:        elfreloc1,
-		ElfrelocSize:     8,
-		Elfsetupplt:      elfsetupplt,
 		Gentext:          gentext,
 		Machoreloc1:      machoreloc1,
 
-		Linuxdynld:     "/lib/ld.so.1",
+		ELF: ld.ELFArch{
-		LinuxdynldMusl: musl,
+			Linuxdynld:     "/lib/ld.so.1",
+			LinuxdynldMusl: musl,
 
-		Freebsddynld:   "XXX",
+			Freebsddynld:   "XXX",
-		Openbsddynld:   "XXX",
+			Openbsddynld:   "XXX",
-		Netbsddynld:    "XXX",
+			Netbsddynld:    "XXX",
-		Dragonflydynld: "XXX",
+			Dragonflydynld: "XXX",
-		Solarisdynld:   "XXX",
+			Solarisdynld:   "XXX",
+
+			Elfreloc1:    elfreloc1,
+			ElfrelocSize: 8,
+			Elfsetupplt:  elfsetupplt,
+		},
 	}
 
 	return arch, theArch

src/cmd/link/internal/mips64/obj.go

@@ -55,19 +55,22 @@ func Init() (*sys.Arch, ld.Arch) {
 		Archreloc:        archreloc,
 		Archrelocvariant: archrelocvariant,
 		Extreloc:         extreloc,
-		Elfreloc1:        elfreloc1,
-		ElfrelocSize:     24,
-		Elfsetupplt:      elfsetupplt,
 		Gentext:          gentext,
 		Machoreloc1:      machoreloc1,
 
-		Linuxdynld:     "/lib64/ld64.so.1",
+		ELF: ld.ELFArch{
-		LinuxdynldMusl: musl,
+			Linuxdynld:     "/lib64/ld64.so.1",
-		Freebsddynld:   "XXX",
+			LinuxdynldMusl: musl,
-		Openbsddynld:   "/usr/libexec/ld.so",
+			Freebsddynld:   "XXX",
-		Netbsddynld:    "XXX",
+			Openbsddynld:   "/usr/libexec/ld.so",
-		Dragonflydynld: "XXX",
+			Netbsddynld:    "XXX",
-		Solarisdynld:   "XXX",
+			Dragonflydynld: "XXX",
+			Solarisdynld:   "XXX",
+
+			Elfreloc1:    elfreloc1,
+			ElfrelocSize: 24,
+			Elfsetupplt:  elfsetupplt,
+		},
 	}
 
 	return arch, theArch

src/cmd/link/internal/ppc64/obj.go

@@ -61,22 +61,25 @@ func Init() (*sys.Arch, ld.Arch) {
 		Archreloc:        archreloc,
 		Archrelocvariant: archrelocvariant,
 		Extreloc:         extreloc,
-		Elfreloc1:        elfreloc1,
-		ElfrelocSize:     24,
-		Elfsetupplt:      elfsetupplt,
 		Gentext:          gentext,
 		Trampoline:       trampoline,
 		Machoreloc1:      machoreloc1,
 		Xcoffreloc1:      xcoffreloc1,
 
-		Linuxdynld:     dynld,
+		ELF: ld.ELFArch{
-		LinuxdynldMusl: musl,
+			Linuxdynld:     dynld,
+			LinuxdynldMusl: musl,
 
-		Freebsddynld:   "XXX",
+			Freebsddynld:   "XXX",
-		Openbsddynld:   "XXX",
+			Openbsddynld:   "XXX",
-		Netbsddynld:    "XXX",
+			Netbsddynld:    "XXX",
-		Dragonflydynld: "XXX",
+			Dragonflydynld: "XXX",
-		Solarisdynld:   "XXX",
+			Solarisdynld:   "XXX",
+
+			Elfreloc1:    elfreloc1,
+			ElfrelocSize: 24,
+			Elfsetupplt:  elfsetupplt,
+		},
 	}
 
 	return arch, theArch

src/cmd/link/internal/riscv64/obj.go

@@ -24,9 +24,6 @@ func Init() (*sys.Arch, ld.Arch) {
 		Archreloc:        archreloc,
 		Archrelocvariant: archrelocvariant,
 		Extreloc:         extreloc,
-		Elfreloc1:        elfreloc1,
-		ElfrelocSize:     24,
-		Elfsetupplt:      elfsetupplt,
 
 		// TrampLimit is set such that we always run the trampoline
 		// generation code. This is necessary since calls to external
@@ -39,13 +36,19 @@ func Init() (*sys.Arch, ld.Arch) {
 		GenSymsLate: genSymsLate,
 		Machoreloc1: machoreloc1,
 
-		Linuxdynld: "/lib/ld.so.1",
+		ELF: ld.ELFArch{
+			Linuxdynld: "/lib/ld.so.1",
 
-		Freebsddynld:   "/usr/libexec/ld-elf.so.1",
+			Freebsddynld:   "/usr/libexec/ld-elf.so.1",
-		Netbsddynld:    "XXX",
+			Netbsddynld:    "XXX",
-		Openbsddynld:   "XXX",
+			Openbsddynld:   "XXX",
-		Dragonflydynld: "XXX",
+			Dragonflydynld: "XXX",
-		Solarisdynld:   "XXX",
+			Solarisdynld:   "XXX",
+
+			Elfreloc1:    elfreloc1,
+			ElfrelocSize: 24,
+			Elfsetupplt:  elfsetupplt,
+		},
 	}
 
 	return arch, theArch

src/cmd/link/internal/s390x/obj.go

@@ -50,21 +50,24 @@ func Init() (*sys.Arch, ld.Arch) {
 		Archinit:         archinit,
 		Archreloc:        archreloc,
 		Archrelocvariant: archrelocvariant,
-		Elfreloc1:        elfreloc1,
-		ElfrelocSize:     24,
-		Elfsetupplt:      elfsetupplt,
 		Gentext:          gentext,
 		Machoreloc1:      machoreloc1,
 
-		Linuxdynld:     "/lib64/ld64.so.1",
+		ELF: ld.ELFArch{
-		LinuxdynldMusl: "/lib/ld-musl-s390x.so.1",
+			Linuxdynld:     "/lib64/ld64.so.1",
+			LinuxdynldMusl: "/lib/ld-musl-s390x.so.1",
 
-		// not relevant for s390x
+			// not relevant for s390x
-		Freebsddynld:   "XXX",
+			Freebsddynld:   "XXX",
-		Openbsddynld:   "XXX",
+			Openbsddynld:   "XXX",
-		Netbsddynld:    "XXX",
+			Netbsddynld:    "XXX",
-		Dragonflydynld: "XXX",
+			Dragonflydynld: "XXX",
-		Solarisdynld:   "XXX",
+			Solarisdynld:   "XXX",
+
+			Elfreloc1:    elfreloc1,
+			ElfrelocSize: 24,
+			Elfsetupplt:  elfsetupplt,
+		},
 	}
 
 	return arch, theArch

src/cmd/link/internal/x86/obj.go

@@ -54,19 +54,22 @@ func Init() (*sys.Arch, ld.Arch) {
 		Archinit:         archinit,
 		Archreloc:        archreloc,
 		Archrelocvariant: archrelocvariant,
-		Elfreloc1:        elfreloc1,
-		ElfrelocSize:     8,
-		Elfsetupplt:      elfsetupplt,
 		Gentext:          gentext,
 		Machoreloc1:      machoreloc1,
 		PEreloc1:         pereloc1,
 
-		Linuxdynld:     "/lib/ld-linux.so.2",
+		ELF: ld.ELFArch{
-		LinuxdynldMusl: "/lib/ld-musl-i386.so.1",
+			Linuxdynld:     "/lib/ld-linux.so.2",
-		Freebsddynld:   "/usr/libexec/ld-elf.so.1",
+			LinuxdynldMusl: "/lib/ld-musl-i386.so.1",
-		Openbsddynld:   "/usr/libexec/ld.so",
+			Freebsddynld:   "/usr/libexec/ld-elf.so.1",
-		Netbsddynld:    "/usr/libexec/ld.elf_so",
+			Openbsddynld:   "/usr/libexec/ld.so",
-		Solarisdynld:   "/lib/ld.so.1",
+			Netbsddynld:    "/usr/libexec/ld.elf_so",
+			Solarisdynld:   "/lib/ld.so.1",
+
+			Elfreloc1:    elfreloc1,
+			ElfrelocSize: 8,
+			Elfsetupplt:  elfsetupplt,
+		},
 	}
 
 	return arch, theArch