Merge pull request #13 from tcbrindle/develop

Fix for Clang not working with MacOS

src/dds/toolchain/from_dds.cpp

         if (!compiler_id) {
             fail(context, "Cannot deduce library file extension without Compiler-ID");
         }
-        if (is_gnu) {
+        if (is_gnu_like) {
             return ".a";
         } else if (is_msvc) {
             return ".lib";
         if (!compiler_id) {
             fail(context, "Cannot deduce object file extension without Compiler-ID");
         }
-        if (is_gnu) {
+        if (is_gnu_like) {
             return ".o";
         } else if (is_msvc) {
             return ".obj";
         string_seq ret;
         if (is_msvc) {
             ret = {get_compiler(language::cxx), "/nologo", "/EHsc", "<IN>", "/Fe<OUT>"};
-        } else if (is_gnu_like) {
+        } else if (is_gnu) {
             ret = {get_compiler(language::cxx),
                    "-fPIC",
                    "-fdiagnostics-color",
                    "-pthread",
                    "-lstdc++fs",
                    "-o<OUT>"};
+        } else if (is_clang) {
+            ret = {get_compiler(language::cxx),
+                   "-fPIC",
+                   "-fdiagnostics-color",
+                   "<IN>",
+                   "-pthread",
+                   "-o<OUT>"};
         } else {
             assert(false && "No link-exe command");
             std::terminate();