cmd/dist, cmd/link, cmd/go: make c-shared work on windows

Thanks to Christopher Nelson for spearheading the effort. Fixes #11058 Change-Id: Icafabac8dc697626ff1bd943cc577b0b1cc6b349 Reviewed-on: https://go-review.googlesource.com/69091 Run-TryBot: Alex Brainman <[email protected]> TryBot-Result: Gobot Gobot <[email protected]> Reviewed-by: Ian Lance Taylor <[email protected]>
golang · Oct 10, 2017 · bb0bfd0 · bb0bfd0
1 parent 0174858
commit bb0bfd0
Show file tree

Hide file tree

Showing 4 changed files with 19 additions and 8 deletions.
diff --git a/src/cmd/dist/test.go b/src/cmd/dist/test.go
@@ -817,7 +817,8 @@ func (t *tester) supportedBuildmode(mode string) bool {
  switch pair {
  case "linux-386", "linux-amd64", "linux-arm", "linux-arm64", "linux-ppc64le",
  "darwin-amd64", "darwin-386",
- "android-arm", "android-arm64", "android-386":
+ "android-arm", "android-arm64", "android-386",
+ "windows-amd64", "windows-386":
  return true
  }
  return false

diff --git a/src/cmd/go/internal/work/build.go b/src/cmd/go/internal/work/build.go
@@ -301,6 +301,9 @@ func BuildModeInit() {
  "android/amd64", "android/arm", "android/arm64", "android/386":
  codegenArg = "-shared"
  case "darwin/amd64", "darwin/386":
+ case "windows/amd64", "windows/386":
+ // Do not add usual .exe suffix to the .dll file.
+ cfg.ExeSuffix = ""
  default:
  base.Fatalf("-buildmode=c-shared not supported on %s\n", platform)
  }
@@ -997,12 +1000,14 @@ func (b *Builder) action1(mode BuildMode, depMode BuildMode, p *load.Package, lo
  name := "a.out"
  if p.Internal.ExeName != "" {
  name = p.Internal.ExeName
- } else if cfg.Goos == "darwin" && cfg.BuildBuildmode == "c-shared" && p.Internal.Target != "" {
+ } else if (cfg.Goos == "darwin" || cfg.Goos == "windows") && cfg.BuildBuildmode == "c-shared" && p.Internal.Target != "" {
  // On OS X, the linker output name gets recorded in the
  // shared library's LC_ID_DYLIB load command.
  // The code invoking the linker knows to pass only the final
  // path element. Arrange that the path element matches what
  // we'll install it as; otherwise the library is only loadable as "a.out".
+ // On Windows, DLL file name is recorded in PE file
+ // export section, so do like on OS X.
  _, name = filepath.Split(p.Internal.Target)
  }
  a.Target = a.Objdir + filepath.Join("exe", name) + cfg.ExeSuffix
@@ -2641,8 +2646,10 @@ func (gcToolchain) ld(b *Builder, root *Action, out, importcfg string, allaction
  // (and making the resulting shared library useless),
  // run the link in the output directory so that -o can name
  // just the final path element.
+ // On Windows, DLL file name is recorded in PE file
+ // export section, so do like on OS X.
  dir := "."
- if cfg.Goos == "darwin" && cfg.BuildBuildmode == "c-shared" {
+ if (cfg.Goos == "darwin" || cfg.Goos == "windows") && cfg.BuildBuildmode == "c-shared" {
  dir, out = filepath.Split(out)
  }
 

diff --git a/src/cmd/internal/obj/x86/asm6.go b/src/cmd/internal/obj/x86/asm6.go
@@ -2290,7 +2290,7 @@ func prefixof(ctxt *obj.Link, p *obj.Prog, a *obj.Addr) int {
  return 0x26
 
  case REG_TLS:
- if ctxt.Flag_shared {
+ if ctxt.Flag_shared && ctxt.Headtype != objabi.Hwindows {
  // When building for inclusion into a shared library, an instruction of the form
  // MOV 0(CX)(TLS*1), AX
  // becomes

diff --git a/src/cmd/link/internal/ld/lib.go b/src/cmd/link/internal/ld/lib.go
@@ -592,7 +592,7 @@ func (ctxt *Link) loadlib() {
  }
 
  if ctxt.Arch == sys.Arch386 {
- if (ctxt.BuildMode == BuildModeCArchive && Iself) || ctxt.BuildMode == BuildModeCShared || ctxt.BuildMode == BuildModePIE || ctxt.DynlinkingGo() {
+ if (ctxt.BuildMode == BuildModeCArchive && Iself) || (ctxt.BuildMode == BuildModeCShared && Headtype != objabi.Hwindows) || ctxt.BuildMode == BuildModePIE || ctxt.DynlinkingGo() {
  got := ctxt.Syms.Lookup("_GLOBAL_OFFSET_TABLE_", 0)
  got.Type = sym.SDYNIMPORT
  got.Attr |= sym.AttrReachable
@@ -1126,9 +1126,12 @@ func (ctxt *Link) hostlink() {
  if ctxt.UseRelro() {
  argv = append(argv, "-Wl,-z,relro")
  }
- // Pass -z nodelete to mark the shared library as
- // non-closeable: a dlclose will do nothing.
- argv = append(argv, "-shared", "-Wl,-z,nodelete")
+ argv = append(argv, "-shared")
+ if Headtype != objabi.Hwindows {
+ // Pass -z nodelete to mark the shared library as
+ // non-closeable: a dlclose will do nothing.
+ argv = append(argv, "-Wl,-z,nodelete")
+ }
  }
  case BuildModeShared:
  if ctxt.UseRelro() {