cmd/link/internal/ld, cmd/go: -buildmode=c-shared support for darwin/amd64

All of the heavy-lifting was done by minux@, with his external-linking support
for darwin/arm64: golang.org/cl/8781

Change-Id: I7c9fbc19246f418c065c92fb2c13c00026ff0f82
Reviewed-on: https://go-review.googlesource.com/11127
Run-TryBot: Srdjan Petrovic <spetrovic@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

diff --git a/misc/cgo/testcshared/test.bash b/misc/cgo/testcshared/test.bash
index 492d25e1342ce43fce883e1c98d3fe980ae3c635..4d3cbccc74842732abc40b5299502c41ebe6da8e 100755 (executable)
--- a/misc/cgo/testcshared/test.bash
+++ b/misc/cgo/testcshared/test.bash
@@ -20,7 +20,7 @@ goarch=$(go env GOARCH)
 # Directory where cgo headers and outputs will be installed.
 # The installation directory format varies depending on the platform.
 installdir=pkg/${goos}_${goarch}_testcshared_shared
-if [ "${goos}/${goarch}" == "android/arm" ]; then
+if [ "${goos}/${goarch}" == "android/arm" ] || [ "${goos}/${goarch}" == "darwin/amd64" ]; then
        installdir=pkg/${goos}_${goarch}_testcshared
 fi
 
@@ -70,15 +70,20 @@ rm -rf pkg
 
 suffix="-installsuffix testcshared"
 
+libext="so"
+if [ "$goos" == "darwin" ]; then
+       libext="dylib"
+fi
+
 # Create the header files.
 GOPATH=$(pwd) go install -buildmode=c-shared $suffix libgo
 
-GOPATH=$(pwd) go build -buildmode=c-shared $suffix -o libgo.so src/libgo/libgo.go
-binpush libgo.so
+GOPATH=$(pwd) go build -buildmode=c-shared $suffix -o libgo.$libext src/libgo/libgo.go
+binpush libgo.$libext
 
 # test0: exported symbols in shared lib are accessible.
 # TODO(iant): using _shared here shouldn't really be necessary.
-$(go env CC) $(go env GOGCCFLAGS) -I ${installdir} -o testp main0.c libgo.so
+$(go env CC) $(go env GOGCCFLAGS) -I ${installdir} -o testp main0.c libgo.$libext
 binpush testp
 
 output=$(run LD_LIBRARY_PATH=. ./testp)
@@ -87,19 +92,23 @@ if [ "$output" != "PASS" ]; then
        exit 1
 fi
 
-# test1: .so can be dynamically loaded and exported symbols are accessible.
+# test1: shared library can be dynamically loaded and exported symbols are accessible.
 $(go env CC) $(go env GOGCCFLAGS) -o testp main1.c -ldl
 binpush testp
-output=$(run ./testp ./libgo.so)
+output=$(run ./testp ./libgo.$libext)
 if [ "$output" != "PASS" ]; then
        echo "FAIL test1 got ${output}"
        exit 1
 fi
 
-# test2: tests libgo2.so which does not export any functions.
-GOPATH=$(pwd) go build -buildmode=c-shared $suffix -o libgo2.so src/libgo2/libgo2.go
-binpush libgo2.so
-$(go env CC) $(go env GOGCCFLAGS) -o testp2 main2.c -Wl,--no-as-needed libgo2.so
+# test2: tests libgo2 which does not export any functions.
+GOPATH=$(pwd) go build -buildmode=c-shared $suffix -o libgo2.$libext src/libgo2/libgo2.go
+binpush libgo2.$libext
+linkflags="-Wl,--no-as-needed"
+if [ "$goos" == "darwin" ]; then
+       linkflags=""
+fi
+$(go env CC) $(go env GOGCCFLAGS) -o testp2 main2.c $linkflags libgo2.$libext
 binpush testp2
 output=$(run LD_LIBRARY_PATH=. ./testp2)
 if [ "$output" != "PASS" ]; then

diff --git a/src/cmd/dist/test.go b/src/cmd/dist/test.go
index 6f1b43cfced29ee96dcb6d3d5219d550db9a33d4..802631dbf98372d8a6b3c266993400c1d0cfcdb7 100644 (file)
--- a/src/cmd/dist/test.go
+++ b/src/cmd/dist/test.go
@@ -571,7 +571,7 @@ func (t *tester) supportedBuildmode(mode string) bool {
        case "c-shared":
                // TODO(hyangah): add linux-386.
                switch pair {
-               case "linux-amd64", "android-arm":
+               case "linux-amd64", "darwin-amd64", "android-arm":
                        return true
                }
                return false

diff --git a/src/cmd/go/build.go b/src/cmd/go/build.go
index 49893de0ed96cb21899b022173f8a6fd7a5c09ef..a9f9b58872182fb3e833d0a180a13568f8c2b245 100644 (file)
--- a/src/cmd/go/build.go
+++ b/src/cmd/go/build.go
@@ -334,6 +334,7 @@ func buildModeInit() {
                                codegenArg = "-shared"
                        case "linux/arm":
                                buildAsmflags = append(buildAsmflags, "-shared")
+                       case "darwin/amd64":
                        case "android/arm":
                        default:
                                fatalf("-buildmode=c-shared not supported on %s\n", platform)

diff --git a/src/cmd/link/internal/ld/lib.go b/src/cmd/link/internal/ld/lib.go
index faa5fc9fd68b5cb5d656223c406731be1a4a2124..ac28439d96891cda7a1302aa378e8511e392ef17 100644 (file)
--- a/src/cmd/link/internal/ld/lib.go
+++ b/src/cmd/link/internal/ld/lib.go
@@ -926,7 +926,7 @@ func hostlink() {
        }
 
        if HEADTYPE == obj.Hdarwin {
-               argv = append(argv, "-Wl,-no_pie,-pagezero_size,4000000,-headerpad,1144")
+               argv = append(argv, "-Wl,-no_pie,-headerpad,1144")
        }
        if HEADTYPE == obj.Hopenbsd {
                argv = append(argv, "-Wl,-nopie")
@@ -944,9 +944,17 @@ func hostlink() {
        }
 
        switch Buildmode {
+       case BuildmodeExe:
+               if HEADTYPE == obj.Hdarwin {
+                       argv = append(argv, "-Wl,-pagezero_size,4000000")
+               }
        case BuildmodeCShared:
-               argv = append(argv, "-Wl,-Bsymbolic")
-               argv = append(argv, "-shared")
+               if HEADTYPE == obj.Hdarwin {
+                       argv = append(argv, "-dynamiclib")
+               } else {
+                       argv = append(argv, "-Wl,-Bsymbolic")
+                       argv = append(argv, "-shared")
+               }
        case BuildmodeShared:
                // TODO(mwhudson): unless you do this, dynamic relocations fill
                // out the findfunctab table and for some reason shared libraries

diff --git a/src/cmd/link/internal/ld/macho.go b/src/cmd/link/internal/ld/macho.go
index 3a8a881d97beecf5e1114e51095248dd5eb207ab..1f14db744fc5821ab91fd2656d84ea085890e76a 100644 (file)
--- a/src/cmd/link/internal/ld/macho.go
+++ b/src/cmd/link/internal/ld/macho.go
@@ -356,9 +356,10 @@ func machoshbits(mseg *MachoSeg, sect *Section, segname string) {
        buf := "__" + strings.Replace(sect.Name[1:], ".", "_", -1)
 
        var msect *MachoSect
-       if Thearch.Thechar == '7' && sect.Rwx&1 == 0 {
-               // darwin/arm64 forbids absolute relocs in __TEXT, so if
-               // the section is not executable, put it in __DATA segment.
+       if sect.Rwx&1 == 0 && (Thearch.Thechar == '7' || (Thearch.Thechar == '6' && Buildmode == BuildmodeCShared)) {
+               // Darwin external linker on arm64 and on amd64 in c-shared buildmode
+               // complains about absolute relocs in __TEXT, so if the section is not
+               // executable, put it in __DATA segment.
                msect = newMachoSect(mseg, buf, "__DATA")
        } else {
                msect = newMachoSect(mseg, buf, segname)

diff --git a/src/cmd/link/internal/ld/macho_combine_dwarf.go b/src/cmd/link/internal/ld/macho_combine_dwarf.go
index 9134373a524a322be2685a8d951dd7c1ef100b64..b5a5a8d4290ced4f60cb064ab31f52fb727eafcd 100644 (file)
--- a/src/cmd/link/internal/ld/macho_combine_dwarf.go
+++ b/src/cmd/link/internal/ld/macho_combine_dwarf.go
@@ -22,6 +22,7 @@ var machHeader *macho.FileHeader
 var mappedHeader []byte
 
 const (
+       LC_ID_DYLIB             = 0xd
        LC_LOAD_DYLINKER        = 0xe
        LC_PREBOUND_DYLIB       = 0x10
        LC_LOAD_WEAK_DYLIB      = 0x18
@@ -246,7 +247,7 @@ func machoCombineDwarf(inexe, dsym, outexe string) error {
                        err = machoUpdateLoadCommand(reader, &linkEditDataCmd{}, "DataOff")
                case LC_ENCRYPTION_INFO, LC_ENCRYPTION_INFO_64:
                        err = machoUpdateLoadCommand(reader, &encryptionInfoCmd{}, "CryptOff")
-               case macho.LoadCmdDylib, macho.LoadCmdThread, macho.LoadCmdUnixThread, LC_PREBOUND_DYLIB, LC_UUID, LC_VERSION_MIN_MACOSX, LC_VERSION_MIN_IPHONEOS, LC_SOURCE_VERSION, LC_MAIN, LC_LOAD_DYLINKER, LC_LOAD_WEAK_DYLIB, LC_REEXPORT_DYLIB, LC_RPATH:
+               case macho.LoadCmdDylib, macho.LoadCmdThread, macho.LoadCmdUnixThread, LC_PREBOUND_DYLIB, LC_UUID, LC_VERSION_MIN_MACOSX, LC_VERSION_MIN_IPHONEOS, LC_SOURCE_VERSION, LC_MAIN, LC_LOAD_DYLINKER, LC_LOAD_WEAK_DYLIB, LC_REEXPORT_DYLIB, LC_RPATH, LC_ID_DYLIB:
                        // Nothing to update
                default:
                        err = fmt.Errorf("Unknown load command 0x%x (%s)\n", int(cmd.Cmd), cmd.Cmd)