flatc now creates the output directory if it doesn't exist yet.

Also cleaned up the general mkdir functionality.

Tested: on OS X.

Tested that a command line like: ./flatc -j -o foo/bar/baz tests/monster_test.fbs
generates files in foo/bar/baz/MyGame/Example/*.java which previously didn't exist.

Windows code was previously tested but has been moved, so needs to be tested again.

Change-Id: Iee943121b3be4f92961a3ec94c2cb578165f114a

src/flatc.cpp

@@ -180,6 +180,7 @@ int main(int argc, const char *argv[]) {
 
       for (size_t i = 0; i < num_generators; ++i) {
         if (generator_enabled[i]) {
+          flatbuffers::EnsureDirExists(output_path);
           if (!generators[i].generate(parser, output_path, filebase, opts)) {
             Error((std::string("Unable to generate ") +
                    generators[i].name +

src/idl_gen_java.cpp

@@ -20,13 +20,6 @@
 #include "flatbuffers/idl.h"
 #include "flatbuffers/util.h"
 
-#ifdef _WIN32
-#include <direct.h>
-#define mkdir(n, m) _mkdir(n)
-#else
-#include <sys/stat.h>
-#endif
-
 namespace flatbuffers {
 namespace java {
 
@@ -351,8 +344,8 @@ static bool SaveClass(const Parser &parser, const Definition &def,
     }
     namespace_java += *it;
     namespace_dir += *it;
-    mkdir(namespace_dir.c_str(), S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH);
   }
+  EnsureDirExists(namespace_dir);
 
   std::string code = "// automatically generated, do not modify\n\n";
   code += "package " + namespace_java + ";\n\n";

src/idl_parser.cpp

@@ -838,7 +838,8 @@ bool Parser::Parse(const char *source, const char *filepath) {
     while (IsNext(kTokenInclude)) {
       auto name = attribute_;
       Expect(kTokenStringConstant);
-      name = StripFileName(filepath) + name;
+      auto path = StripFileName(filepath);
+      if (path.length()) name = path + kPathSeparator + name;
       if (included_files_.find(name) == included_files_.end()) {
         // We found an include file that we have not parsed yet.
         // Load it and parse it.