cmd/internal/ld, cmd/6l: external linking for windows/amd64

Change-Id: I2d2ea233f976aab3f356f9b508cdd246d5013e30
Signed-off-by: Shenghou Ma <minux@golang.org>
Reviewed-on: https://go-review.googlesource.com/7534
Reviewed-by: Ian Lance Taylor <iant@golang.org>

2 files changed, 52 insertions, 5 deletions

diff --git a/src/cmd/6l/asm.go b/src/cmd/6l/asm.go
index 3617a95bf5..1df166f100 100644
--- a/src/cmd/6l/asm.go
+++ b/src/cmd/6l/asm.go
@@ -204,10 +204,16 @@ func adddynrel(s *ld.LSym, r *ld.Reloc) {
 	switch r.Type {
 	case ld.R_CALL,
 		ld.R_PCREL:
-		addpltsym(targ)
-		r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
-		r.Add = int64(targ.Plt)
-		return
+		if ld.HEADTYPE == ld.Hwindows {
+			// nothing to do, the relocation will be laid out in pereloc1
+			return
+		} else {
+			// for both ELF and Mach-O
+			addpltsym(targ)
+			r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
+			r.Add = int64(targ.Plt)
+			return
+		}
 
 	case ld.R_ADDR:
 		if s.Type == ld.STEXT && ld.Iself {
@@ -262,6 +268,11 @@ func adddynrel(s *ld.LSym, r *ld.Reloc) {
 			r.Type = 256 // ignore during relocsym
 			return
 		}
+
+		if ld.HEADTYPE == ld.Hwindows {
+			// nothing to do, the relocation will be laid out in pereloc1
+			return
+		}
 	}
 
 	ld.Ctxt.Cursym = s
@@ -393,6 +404,40 @@ 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:
+		if r.Siz == 8 {
+			v = ld.IMAGE_REL_AMD64_ADDR64
+		} else {
+			v = ld.IMAGE_REL_AMD64_ADDR32
+		}
+
+	case ld.R_CALL,
+		ld.R_PCREL:
+		v = ld.IMAGE_REL_AMD64_REL32
+	}
+
+	ld.Thearch.Wput(uint16(v))
+
+	return true
+}
+
 func archreloc(r *ld.Reloc, s *ld.LSym, val *int64) int {
 	return -1
 }
diff --git a/src/cmd/6l/obj.go b/src/cmd/6l/obj.go
index e8c93c90fb..f7165ab05e 100644
--- a/src/cmd/6l/obj.go
+++ b/src/cmd/6l/obj.go
@@ -71,6 +71,7 @@ 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
@@ -110,7 +111,8 @@ func archinit() {
 		ld.Hnacl,
 		ld.Hnetbsd,
 		ld.Hopenbsd,
-		ld.Hsolaris:
+		ld.Hsolaris,
+		ld.Hwindows:
 		break
 	}