ruby: dlopen libruby -- currently segfaults with rb1.9 ...

plugins/ruby/CMakeLists.txt

@@ -1,15 +1,9 @@
-find_package(Ruby)
-if(RUBY_FOUND)
 ADD_CUSTOM_COMMAND(
     OUTPUT ruby-autogen.rb
     COMMAND ${PERL_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/codegen.pl ${dfhack_SOURCE_DIR}/library/include/df/codegen.out.xml ${CMAKE_CURRENT_SOURCE_DIR}/ruby-autogen.rb
     DEPENDS ${dfhack_SOURCE_DIR}/library/include/df/codegen.out.xml codegen.pl
 )
 ADD_CUSTOM_TARGET(ruby-autogen-rb ALL DEPENDS ruby-autogen.rb)
-    include_directories("${dfhack_SOURCE_DIR}/depends/tthread" ${RUBY_INCLUDE_PATH})
+include_directories("${dfhack_SOURCE_DIR}/depends/tthread")
 DFHACK_PLUGIN(ruby ruby.cpp LINK_LIBRARIES dfhack-tinythread)
-    target_link_libraries(ruby ${RUBY_LIBRARY})
 install(FILES ruby.rb ruby-autogen.rb DESTINATION ${DFHACK_LIBRARY_DESTINATION})
-else(RUBY_FOUND)
-    MESSAGE(STATUS "Required library (ruby) not found - ruby plugin can't be built.")
-endif(RUBY_FOUND)

plugins/ruby/ruby.cpp

@@ -11,8 +11,6 @@
 
 #include "tinythread.h"
 
-#include <ruby.h>
-
 using namespace DFHack;
 
 
@@ -20,6 +18,8 @@ using namespace DFHack;
 // DFHack stuff
 
 
+static int df_loadruby(void);
+static void df_unloadruby(void);
 static void df_rubythread(void*);
 static command_result df_rubyload(color_ostream &out, std::vector <std::string> & parameters);
 static command_result df_rubyeval(color_ostream &out, std::vector <std::string> & parameters);
@@ -45,6 +45,11 @@ DFHACK_PLUGIN("ruby")
 
 DFhackCExport command_result plugin_init ( color_ostream &out, std::vector <PluginCommand> &commands)
 {
+    if (!df_loadruby()) {
+        Core::printerr("failed to load libruby\n");
+        return CR_FAILURE;
+    }
+
     m_irun = new tthread::mutex();
     m_mutex = new tthread::mutex();
     r_type = RB_INIT;
@@ -90,6 +95,8 @@ DFhackCExport command_result plugin_shutdown ( color_ostream &out )
     m_mutex->unlock();
     delete m_mutex;
 
+    df_unloadruby();
+
     return CR_OK;
 }
 
@@ -191,6 +198,111 @@ static command_result df_rubyeval(color_ostream &out, std::vector <std::string>
 
 // ruby stuff
 
+// ruby-dev on windows is messy
+// ruby.h on linux 64 is broken
+// so we dynamically load libruby instead of linking it at compile time
+// lib path can be set in dfhack.ini to use the system libruby, but by
+// default we'll embed our own (downloaded by cmake)
+
+// these ruby definitions are invalid for windows 64bit
+typedef unsigned long VALUE;
+typedef unsigned long ID;
+
+#define Qfalse ((VALUE)0)
+#define Qtrue  ((VALUE)2)
+#define Qnil   ((VALUE)4)
+
+#define INT2FIX(i) ((VALUE)((((long)i) << 1) | 1))
+#define FIX2INT(i) (((long)i) >> 1)
+#define RUBY_METHOD_FUNC(func) ((VALUE(*)(...))func)
+
+VALUE *rb_eRuntimeError;
+
+void (*ruby_sysinit)(int *, const char ***);
+void (*ruby_init)(void);
+void (*ruby_init_loadpath)(void);
+void (*ruby_script)(const char*);
+void (*ruby_finalize)(void);
+ID (*rb_intern)(const char*);
+VALUE (*rb_raise)(VALUE, const char*, ...);
+VALUE (*rb_funcall)(VALUE, ID, int, ...);
+VALUE (*rb_define_module)(const char*);
+void (*rb_define_singleton_method)(VALUE, const char*, VALUE(*)(...), int);
+void (*rb_define_const)(VALUE, const char*, VALUE);
+void (*rb_load_protect)(VALUE, int, int*);
+VALUE (*rb_gv_get)(const char*);
+VALUE (*rb_str_new)(const char*, long);
+VALUE (*rb_str_new2)(const char*);
+char* (*rb_string_value_ptr)(VALUE*);
+VALUE (*rb_eval_string_protect)(const char*, int*);
+VALUE (*rb_ary_shift)(VALUE);
+VALUE (*rb_float_new)(double);
+double (*rb_num2dbl)(VALUE);
+VALUE (*rb_int2inum)(long);
+VALUE (*rb_uint2inum)(unsigned long);
+unsigned long (*rb_num2ulong)(VALUE);
+// end of rip(ruby.h)
+
+DFHack::DFLibrary *libruby_handle;
+
+// load the ruby library, initialize function pointers
+static int df_loadruby(void)
+{
+    const char *libpath =
+#ifdef WIN32
+        "msvcrt-ruby191.dll";
+#else
+        "libruby1.9.so.1.9.0";
+#endif
+
+    libruby_handle = OpenPlugin(libpath);
+    if (!libruby_handle)
+        return 0;
+
+    if (!(rb_eRuntimeError = (VALUE*)LookupPlugin(libruby_handle, "rb_eRuntimeError")))
+        return 0;
+
+    // XXX does msvc support decltype ? might need a #define decltype typeof
+    // or just assign to *(void**)(&s) = ...
+    // ruby_sysinit is optional (ruby1.9 only)
+    ruby_sysinit = (decltype(ruby_sysinit))LookupPlugin(libruby_handle, "ruby_sysinit");
+#define rbloadsym(s) if (!(s = (decltype(s))LookupPlugin(libruby_handle, #s))) return 0
+    rbloadsym(ruby_init);
+    rbloadsym(ruby_init_loadpath);
+    rbloadsym(ruby_script);
+    rbloadsym(ruby_finalize);
+    rbloadsym(rb_intern);
+    rbloadsym(rb_raise);
+    rbloadsym(rb_funcall);
+    rbloadsym(rb_define_module);
+    rbloadsym(rb_define_singleton_method);
+    rbloadsym(rb_define_const);
+    rbloadsym(rb_load_protect);
+    rbloadsym(rb_gv_get);
+    rbloadsym(rb_str_new);
+    rbloadsym(rb_str_new2);
+    rbloadsym(rb_string_value_ptr);
+    rbloadsym(rb_eval_string_protect);
+    rbloadsym(rb_ary_shift);
+    rbloadsym(rb_float_new);
+    rbloadsym(rb_num2dbl);
+    rbloadsym(rb_int2inum);
+    rbloadsym(rb_uint2inum);
+    rbloadsym(rb_num2ulong);
+#undef rbloadsym
+
+    return 1;
+}
+
+static void df_unloadruby(void)
+{
+    if (libruby_handle) {
+        ClosePlugin(libruby_handle);
+        libruby_handle = 0;
+    }
+}
+
+
 // ruby thread code
 static void dump_rb_error(void)
 {
@@ -353,7 +465,7 @@ static VALUE rb_dfregister(VALUE self, VALUE name, VALUE descr)
 */
 static VALUE rb_dfregister(VALUE self, VALUE name, VALUE descr)
 {
-    rb_raise(rb_eRuntimeError, "not implemented");
+    rb_raise(*rb_eRuntimeError, "not implemented");
 }
 
 static VALUE rb_dfget_global_address(VALUE self, VALUE name)
@@ -402,7 +514,7 @@ static VALUE rb_dfmalloc(VALUE self, VALUE len)
 {
     char *ptr = (char*)malloc(FIX2INT(len));
     if (!ptr)
-        rb_raise(rb_eRuntimeError, "no memory");
+        rb_raise(*rb_eRuntimeError, "no memory");
     memset(ptr, 0, FIX2INT(len));
     return rb_uint2inum((long)ptr);
 }