Merge branch 'ahnolds-clean_osx_go'

* ahnolds-clean_osx_go:
  Go test-suite should now work on OSX
  Don't write empty swigargs structs
  Fail if nocgo version fails
  Handle weak linking on OSX

Conflicts:
	CHANGES.current

4 files changed, 26 insertions, 9 deletions

diff --git a/.travis.yml b/.travis.yml
index 97cfc2df1..2d174676f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -162,9 +162,6 @@ matrix:
     - compiler: gcc
       os: linux
       env: SWIGLANG=python SWIG_FEATURES=-O
-    - compiler: clang
-      os: osx
-      env: SWIGLANG=go
 before_install:
   - date -u
   - uname -a
diff --git a/CHANGES.current b/CHANGES.current
index 90297e917..2a0017822 100644
--- a/CHANGES.current
+++ b/CHANGES.current
@@ -8,6 +8,15 @@ Version 3.0.9 (in progress)
 2016-01-27: steeve
             [Go] Ensure structs are properly packed between gc and GCC/clang.
 
+2016-01-23: ahnolds
+            [Go] Enable support for the Go test-suite on OSX:
+            * The linker on OSX requires that all symbols (even weak symbols)
+              are defined at link time. Because the function _cgo_topofstack is
+              only defined starting in Go version 1.4, we explicitly mark it as
+              undefined for older versions of Go on OSX.
+            * Avoid writing empty swigargs structs, since empty structs are not
+              allowed in extern "C" blocks.
+
 2016-01-12: olly
 	    [Javascript] Look for "nodejs" as well as "node", as it's packaged
 	    as the former on Debian.
diff --git a/Examples/test-suite/go/Makefile.in b/Examples/test-suite/go/Makefile.in
index 7fb97eb02..01989b0d3 100644
--- a/Examples/test-suite/go/Makefile.in
+++ b/Examples/test-suite/go/Makefile.in
@@ -11,6 +11,8 @@ GO12		= @GO12@
 GO13		= @GO13@
 GO15		= @GO15@
 GOC		= @GOC@
+GOVERSIONOPTION	= @GOVERSIONOPTION@
+host		= @host@
 SCRIPTSUFFIX	= _runme.go
 
 GOCOMPILEARG = `if $(GO15); then echo tool compile; elif $(GO1); then echo tool $(GOC:c=g); fi`
@@ -20,6 +22,8 @@ GOPACK = `if $(GO1) ; then echo go tool pack; else echo gopack; fi`
 
 GOOBJEXT = `if $(GO15); then echo o; else echo $(GOC:c=); fi`
 
+OSXOLDGOLINKFLAGS	= `if [ -n "\`$(GO) $(GOVERSIONOPTION) | grep -E 'go1($|.0|.1|.2|.3)'\`" ] && [ -n "\`echo $(host) | grep darwin\`" ]; then echo "-Wl,-U,__cgo_topofstack"; fi`
+
 SO = @SO@
 
 srcdir         = @srcdir@
@@ -50,7 +54,7 @@ INCLUDES = -I$(abs_top_srcdir)/$(EXAMPLES)/$(TEST_SUITE)
 	  SWIG_LIB_DIR='$(SWIG_LIB_DIR)' SWIGEXE='$(SWIGEXE)' \
 	  INCLUDES='$(INCLUDES)' SWIGOPT='$(SWIGOPT)' NOLINK=true \
 	  TARGET='$(TARGETPREFIX)$*$(TARGETSUFFIX)' INTERFACEDIR='$(INTERFACEDIR)' INTERFACE='$*.i' \
-	  $(LANGUAGE)$(VARIANT)_cpp_nocgo; \
+	  $(LANGUAGE)$(VARIANT)_cpp_nocgo && \
 	  $(run_testcase_cpp); \
 	fi
 
@@ -63,7 +67,7 @@ INCLUDES = -I$(abs_top_srcdir)/$(EXAMPLES)/$(TEST_SUITE)
 	  SWIG_LIB_DIR='$(SWIG_LIB_DIR)' SWIGEXE='$(SWIGEXE)' \
 	  INCLUDES='$(INCLUDES)' SWIGOPT='$(SWIGOPT)' NOLINK=true \
 	  TARGET='$(TARGETPREFIX)$*$(TARGETSUFFIX)' INTERFACEDIR='$(INTERFACEDIR)' INTERFACE='$*.i' \
-	  $(LANGUAGE)$(VARIANT)_nocgo; \
+	  $(LANGUAGE)$(VARIANT)_nocgo && \
 	  $(run_testcase); \
 	fi
 
@@ -121,7 +125,7 @@ run_testcase = \
 	    $(COMPILETOOL) $(GCCGO) -o $*_runme $(SCRIPTPREFIX)$*_runme.@OBJEXT@ $*.a; \
 	  elif $(GO12) || $(GO13) || $(GO15); then \
 	    $(COMPILETOOL) $(GO) $(GOCOMPILEARG) -I . $(SCRIPTDIR)/$(SCRIPTPREFIX)$*$(SCRIPTSUFFIX) && \
-	    $(COMPILETOOL) $(GOTOOL) $(GOLD) -linkmode external -extld $(CC) -extldflags "$(CFLAGS)" -o $*_runme $(SCRIPTPREFIX)$*_runme.$(GOOBJEXT); \
+	    $(COMPILETOOL) $(GOTOOL) $(GOLD) -linkmode external -extld $(CC) -extldflags "$(CFLAGS) $(OSXOLDGOLINKFLAGS)" -o $*_runme $(SCRIPTPREFIX)$*_runme.$(GOOBJEXT); \
 	  else \
 	    $(COMPILETOOL) $(GO) $(GOCOMPILEARG) -I . $(SCRIPTDIR)/$(SCRIPTPREFIX)$*$(SCRIPTSUFFIX) && \
 	    $(COMPILETOOL) $(GOTOOL) $(GOLD) -L . -r $${GOROOT:-`go env GOROOT`}/pkg/$${GOOS:-`go env GOOS`}_$${GOARCH:-`go env GOARCH`}:. -o $*_runme $(SCRIPTPREFIX)$*_runme.$(GOOBJEXT); \
@@ -136,7 +140,7 @@ run_testcase_cpp = \
 	    $(COMPILETOOL) $(GCCGO) -o $*_runme $(SCRIPTPREFIX)$*_runme.@OBJEXT@ $*.a -lstdc++; \
 	  elif $(GO12) || $(GO13) || $(GO15); then \
 	    $(COMPILETOOL) $(GO) $(GOCOMPILEARG) -I . $(SCRIPTDIR)/$(SCRIPTPREFIX)$*$(SCRIPTSUFFIX) && \
-	    $(COMPILETOOL) $(GOTOOL) $(GOLD) -linkmode external -extld $(CXX) -extldflags "$(CXXFLAGS)" -o $*_runme $(SCRIPTPREFIX)$*_runme.$(GOOBJEXT); \
+	    $(COMPILETOOL) $(GOTOOL) $(GOLD) -linkmode external -extld $(CXX) -extldflags "$(CXXFLAGS) $(OSXOLDGOLINKFLAGS)" -o $*_runme $(SCRIPTPREFIX)$*_runme.$(GOOBJEXT); \
 	  else \
 	    $(COMPILETOOL) $(GO) $(GOCOMPILEARG) -I . $(SCRIPTDIR)/$(SCRIPTPREFIX)$*$(SCRIPTSUFFIX) && \
 	    $(COMPILETOOL) $(GOTOOL) $(GOLD) -L . -r $${GOROOT:-`go env GOROOT`}/pkg/$${GOOS:-`go env GOOS`}_$${GOARCH:-`go env GOARCH`}:. -o $*_runme $(SCRIPTPREFIX)$*_runme.$(GOOBJEXT); \
@@ -152,7 +156,7 @@ run_multi_testcase = \
 	    $(COMPILETOOL) $(GCCGO) -o $*_runme $(SCRIPTPREFIX)$*_runme.@OBJEXT@ `for f in $$files; do echo $$f.a; done` -lstdc++; \
 	  elif $(GO12) || $(GO13) || $(GO15); then \
 	    $(COMPILETOOL) $(GO) $(GOCOMPILEARG) -I . $(SCRIPTDIR)/$(SCRIPTPREFIX)$*$(SCRIPTSUFFIX) && \
-	    $(COMPILETOOL) $(GOTOOL) $(GOLD) -L . -linkmode external -extld $(CXX) -extldflags "$(CXXFLAGS)" -o $*_runme $(SCRIPTPREFIX)$*_runme.$(GOOBJEXT); \
+	    $(COMPILETOOL) $(GOTOOL) $(GOLD) -L . -linkmode external -extld $(CXX) -extldflags "$(CXXFLAGS) $(OSXOLDGOLINKFLAGS)" -o $*_runme $(SCRIPTPREFIX)$*_runme.$(GOOBJEXT); \
 	  else \
 	    $(COMPILETOOL) $(GO) $(GOCOMPILEARG) -I . $(SCRIPTDIR)/$(SCRIPTPREFIX)$*$(SCRIPTSUFFIX) && \
 	    $(COMPILETOOL) $(GOTOOL) $(GOLD) -L . -r $${GOROOT:-`go env GOROOT`}/pkg/$${GOOS:-`go env GOOS`}_$${GOARCH:-`go env GOARCH`}:. -o $*_runme $(SCRIPTPREFIX)$*_runme.$(GOOBJEXT); \
diff --git a/Source/Modules/go.cxx b/Source/Modules/go.cxx
index a4445a95d..002247fe5 100644
--- a/Source/Modules/go.cxx
+++ b/Source/Modules/go.cxx
@@ -2112,6 +2112,7 @@ private:
     emit_attach_parmmaps(parms, f);
     int parm_count = emit_num_arguments(parms);
     int required_count = emit_num_required(parms);
+    bool needs_swigargs = false;
 
     emit_return_variable(n, result, f);
 
@@ -2125,6 +2126,7 @@ private:
     String *swigargs = NewString("\tstruct swigargs {\n");
 
     if (parm_count > required_count) {
+      needs_swigargs = true;
       Printv(swigargs, "\t\tintgo _swig_optargc;\n", NULL);
     }
 
@@ -2136,6 +2138,7 @@ private:
       SwigType *pt = Getattr(p, "type");
       String *ct = gcCTypeForGoValue(p, pt, ln);
       Printv(swigargs, "\t\t\t", ct, ";\n", NULL);
+      needs_swigargs = true;
       Delete(ct);
 
       String *gn = NewStringf("_swig_go_%d", i);
@@ -2152,6 +2155,7 @@ private:
       String *ct = gcCTypeForGoValue(n, result, ln);
       Delete(ln);
       Printv(swigargs, "\t\t", ct, ";\n", NULL);
+      needs_swigargs = true;
       Delete(ct);
 
       ln = NewString("_swig_go_result");
@@ -2208,7 +2212,10 @@ private:
 
     cleanupFunction(n, f, parms);
 
-    Printv(f->locals, swigargs, NULL);
+    if (needs_swigargs)
+    {
+      Printv(f->locals, swigargs, NULL);
+    }
 
     Printv(f->code, "}\n", NULL);