cmd/internal/ld, cmd/8l: external linking for windows/386

Update #4069: this CL fixes the issue on windows/386.
Signed-off-by: Shenghou Ma <minux@golang.org>
Change-Id: I2d2ea233f976aab3f356f9b508cdd246d5013e2e
Reviewed-on: https://go-review.googlesource.com/7283Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/cmd/8l/asm.go

@@ -235,6 +235,11 @@ func adddynrel(s *ld.LSym, r *ld.Reloc) {
 			r.Type = 256 // ignore during relocsym
 			return
 		}
+
+		if ld.HEADTYPE == ld.Hwindows && s.Size == PtrSize {
+			// nothing to do, the relocation will be laid out in pereloc1
+			return
+		}
 	}
 
 	ld.Ctxt.Cursym = s
@@ -332,6 +337,36 @@ func machoreloc1(r *ld.Reloc, sectoff int64) int {
 	return 0
 }
 
+func pereloc1(r *ld.Reloc, sectoff int64) bool {
+	var v uint32
+
+	rs := r.Xsym
+
+	if rs.Dynid < 0 {
+		ld.Diag("reloc %d to non-coff symbol %s type=%d", r.Type, rs.Name, rs.Type)
+		return false
+	}
+
+	ld.Thearch.Lput(uint32(sectoff))
+	ld.Thearch.Lput(uint32(rs.Dynid))
+
+	switch r.Type {
+	default:
+		return false
+
+	case ld.R_ADDR:
+		v = ld.IMAGE_REL_I386_DIR32
+
+	case ld.R_CALL,
+		ld.R_PCREL:
+		v = ld.IMAGE_REL_I386_REL32
+	}
+
+	ld.Thearch.Wput(uint16(v))
+
+	return true
+}
+
 func archreloc(r *ld.Reloc, s *ld.LSym, val *int64) int {
 	if ld.Linkmode == ld.LinkExternal {
 		return -1

src/cmd/8l/obj.go

@@ -68,6 +68,7 @@ func linkarchinit() {
 	ld.Thearch.Elfsetupplt = elfsetupplt
 	ld.Thearch.Gentext = gentext
 	ld.Thearch.Machoreloc1 = machoreloc1
+	ld.Thearch.PEreloc1 = pereloc1
 	ld.Thearch.Lput = ld.Lputl
 	ld.Thearch.Wput = ld.Wputl
 	ld.Thearch.Vput = ld.Vputl
@@ -99,7 +100,8 @@ func archinit() {
 		ld.Hfreebsd,
 		ld.Hlinux,
 		ld.Hnetbsd,
-		ld.Hopenbsd:
+		ld.Hopenbsd,
+		ld.Hwindows:
 		break
 	}
 

src/cmd/internal/ld/data.go

@@ -443,6 +443,8 @@ func relocsym(s *LSym) {
 					if rs.Type != SHOSTOBJ {
 						o += Symaddr(rs)
 					}
+				} else if HEADTYPE == Hwindows {
+					// nothing to do
 				} else {
 					Diag("unhandled pcrel relocation for %s", headstring)
 				}
@@ -497,6 +499,8 @@ func relocsym(s *LSym) {
 					} else {
 						o += int64(r.Siz)
 					}
+				} else if HEADTYPE == Hwindows {
+					// nothing to do
 				} else {
 					Diag("unhandled pcrel relocation for %s", headstring)
 				}
@@ -584,7 +588,7 @@ func reloc() {
 }
 
 func dynrelocsym(s *LSym) {
-	if HEADTYPE == Hwindows {
+	if HEADTYPE == Hwindows && Linkmode != LinkExternal {
 		rel := Linklookup(Ctxt, ".rel", 0)
 		if s == rel {
 			return

src/cmd/internal/ld/go.go

@@ -462,11 +462,6 @@ func loadcgo(file string, pkg string, p string) {
 		}
 
 		if f[0] == "cgo_export_static" || f[0] == "cgo_export_dynamic" {
-			// TODO: Remove once we know Windows is okay.
-			if f[0] == "cgo_export_static" && HEADTYPE == Hwindows {
-				continue
-			}
-
 			if len(f) < 2 || len(f) > 3 {
 				goto err
 			}

src/cmd/internal/ld/lib.go

@@ -99,6 +99,7 @@ type Arch struct {
 	Elfsetupplt      func()
 	Gentext          func()
 	Machoreloc1      func(*Reloc, int64) int
+	PEreloc1         func(*Reloc, int64) bool
 	Lput             func(uint32)
 	Wput             func(uint16)
 	Vput             func(uint64)
@@ -744,6 +745,13 @@ func hostlink() {
 	if HEADTYPE == Hopenbsd {
 		argv = append(argv, "-Wl,-nopie")
 	}
+	if HEADTYPE == Hwindows {
+		if headstring == "windowsgui" {
+			argv = append(argv, "-mwindows")
+		} else {
+			argv = append(argv, "-mconsole")
+		}
+	}
 
 	if Iself && AssumeGoldLinker != 0 /*TypeKind(100016)*/ {
 		argv = append(argv, "-Wl,--rosegment")
@@ -844,6 +852,9 @@ func hostlink() {
 			}
 		}
 	}
+	if HEADTYPE == Hwindows {
+		argv = append(argv, peimporteddlls()...)
+	}
 
 	if Debug['v'] != 0 {
 		fmt.Fprintf(&Bso, "host link:")
@@ -1379,6 +1390,13 @@ func genasmsym(put func(*LSym, string, int, int64, int64, int, *LSym)) {
 		case SFILE:
 			put(nil, s.Name, 'f', s.Value, 0, int(s.Version), nil)
 			continue
+
+		case SHOSTOBJ:
+			if HEADTYPE == Hwindows {
+				put(s, s.Name, 'U', s.Value, 0, int(s.Version), nil)
+			}
+			continue
+
 		}
 	}