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>

diff --git a/src/cmd/6l/asm.go b/src/cmd/6l/asm.go
index 3617a95bf559e90aac3416e760c899ce7634f7c1..1df166f100ad35e480386d036cd2eee940a2e905 100644 (file)
--- 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 e8c93c90fbc3fcb363c449136cc2e1232428a433..f7165ab05e0d4341b391c3df2e7429aed98642b2 100644 (file)
--- 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
        }
 

diff --git a/src/cmd/internal/ld/data.go b/src/cmd/internal/ld/data.go
index 196b13efb46b1e09be692124cf66a89327343b44..b7de5af9fb378adad08a40e5f4b2265ff58d44b3 100644 (file)
--- a/src/cmd/internal/ld/data.go
+++ b/src/cmd/internal/ld/data.go
@@ -499,8 +499,13 @@ func relocsym(s *LSym) {
                                        } else {
                                                o += int64(r.Siz)
                                        }
-                               } else if HEADTYPE == Hwindows {
-                                       // nothing to do
+                               } else if HEADTYPE == Hwindows && Thearch.Thechar == '6' { // only amd64 needs PCREL
+                                       // PE/COFF's PC32 relocation uses the address after the relocated
+                                       // bytes as the base. Compensate by skewing the addend.
+                                       o += int64(r.Siz)
+                                       // GNU ld always add VirtualAddress of the .text section to the
+                                       // relocated address, compensate that.
+                                       o -= int64(s.Sect.(*Section).Vaddr - PEBASE)
                                } else {
                                        Diag("unhandled pcrel relocation for %s", headstring)
                                }

diff --git a/src/cmd/internal/ld/pe.go b/src/cmd/internal/ld/pe.go
index 4116f358b997ef87ae43b8e852314879110b2032..8df5ca44cd6246ffe3cafaa8f3c223d0304b3f0d 100644 (file)
--- a/src/cmd/internal/ld/pe.go
+++ b/src/cmd/internal/ld/pe.go
@@ -532,7 +532,8 @@ func initdynimport() *Dll {
                                m.s.Type = SDATA
                                Symgrow(Ctxt, m.s, int64(Thearch.Ptrsize))
                                dynName := m.s.Extname
-                               if m.argsize >= 0 {
+                               // only windows/386 requires stdcall decoration
+                               if Thearch.Thechar == '8' && m.argsize >= 0 {
                                        dynName += fmt.Sprintf("@%d", m.argsize)
                                }
                                dynSym := Linklookup(Ctxt, dynName, 0)
@@ -955,7 +956,8 @@ func addpesym(s *LSym, name string, type_ int, addr int64, size int64, ver int,
        }
 
        if coffsym != nil {
-               if Linkmode == LinkExternal && (s.Type == SHOSTOBJ || s.Cgoexport != 0) && s.Name == s.Extname {
+               // only windows/386 requires underscore prefix on external symbols
+               if Thearch.Thechar == '8' && Linkmode == LinkExternal && (s.Type == SHOSTOBJ || s.Cgoexport != 0) && s.Name == s.Extname {
                        s.Name = "_" + s.Name
                }
                cs := &coffsym[ncoffsym]
@@ -963,7 +965,9 @@ func addpesym(s *LSym, name string, type_ int, addr int64, size int64, ver int,
                if len(s.Name) > 8 {
                        cs.strtbloff = strtbladd(s.Name)
                }
-               if uint64(s.Value) >= Segdata.Vaddr+Segdata.Filelen && Linkmode == LinkExternal {
+               // Note: although address of runtime.edata (type SDATA) is at the start of .bss section
+               // it still belongs to the .data section, not the .bss section.
+               if uint64(s.Value) >= Segdata.Vaddr+Segdata.Filelen && s.Type != SDATA && Linkmode == LinkExternal {
                        cs.value = int64(uint64(s.Value) - Segdata.Vaddr - Segdata.Filelen)
                        cs.sect = bsssect
                } else if uint64(s.Value) >= Segdata.Vaddr {