win32ole: separate global variable declarations and definitions

https://gcc.gnu.org/gcc-10/changes.html#c

> * GCC now defaults to `-fno-common`.  As a result, global
>   variable accesses are more efficient on various targets.  In
>   C, global variables with multiple tentative definitions now
>   result in linker errors.  With `-fcommon` such definitions are
>   silently merged during linking.

ext/win32ole/win32ole.c

@@ -3962,6 +3962,7 @@ check_nano_server(void)
     }
 }
 
+LCID cWIN32OLE_lcid;
 
 void
 Init_win32ole(void)

ext/win32ole/win32ole.h

@@ -112,8 +112,8 @@ struct oledata {
     IDispatch *pDispatch;
 };
 
-VALUE cWIN32OLE;
-LCID cWIN32OLE_lcid;
+extern VALUE cWIN32OLE;
+extern LCID cWIN32OLE_lcid;
 
 struct oledata *oledata_get_struct(VALUE obj);
 LPWSTR ole_vstr2wc(VALUE vstr);

ext/win32ole/win32ole_error.c

@@ -60,6 +60,9 @@ ole_raise(HRESULT hr, VALUE ecs, const char *fmt, ...)
     rb_exc_raise(rb_exc_new_str(ecs, msg));
 }
 
+VALUE eWIN32OLERuntimeError;
+VALUE eWIN32OLEQueryInterfaceError;
+
 void
 Init_win32ole_error(void)
 {

ext/win32ole/win32ole_error.h

@@ -1,8 +1,8 @@
 #ifndef WIN32OLE_ERROR_H
 #define WIN32OLE_ERROR_H 1
 
-VALUE eWIN32OLERuntimeError;
-VALUE eWIN32OLEQueryInterfaceError;
+extern VALUE eWIN32OLERuntimeError;
+extern VALUE eWIN32OLEQueryInterfaceError;
 NORETURN(PRINTF_ARGS(void ole_raise(HRESULT hr, VALUE ecs, const char *fmt, ...), 3, 4));
 void Init_win32ole_error(void);
 

ext/win32ole/win32ole_method.c

@@ -923,6 +923,8 @@ folemethod_inspect(VALUE self)
     return default_inspect(self, "WIN32OLE_METHOD");
 }
 
+VALUE cWIN32OLE_METHOD;
+
 void Init_win32ole_method(void)
 {
     cWIN32OLE_METHOD = rb_define_class("WIN32OLE_METHOD", rb_cObject);

ext/win32ole/win32ole_method.h

@@ -7,7 +7,7 @@ struct olemethoddata {
     UINT index;
 };
 
-VALUE cWIN32OLE_METHOD;
+extern VALUE cWIN32OLE_METHOD;
 VALUE folemethod_s_allocate(VALUE klass);
 VALUE ole_methods_from_typeinfo(ITypeInfo *pTypeInfo, int mask);
 VALUE create_win32ole_method(ITypeInfo *pTypeInfo, VALUE name);

ext/win32ole/win32ole_record.c

@@ -589,6 +589,8 @@ folerecord_inspect(VALUE self)
                       field);
 }
 
+VALUE cWIN32OLE_RECORD;
+
 void
 Init_win32ole_record(void)
 {

ext/win32ole/win32ole_record.h

@@ -1,7 +1,7 @@
 #ifndef WIN32OLE_RECORD_H
 #define WIN32OLE_RECORD_H 1
 
-VALUE cWIN32OLE_RECORD;
+extern VALUE cWIN32OLE_RECORD;
 void ole_rec2variant(VALUE rec, VARIANT *var);
 void olerecord_set_ivar(VALUE obj, IRecordInfo *pri, void *prec);
 VALUE create_win32ole_record(IRecordInfo *pri, void *prec);

ext/win32ole/win32ole_type.c

@@ -883,6 +883,8 @@ foletype_inspect(VALUE self)
     return default_inspect(self, "WIN32OLE_TYPE");
 }
 
+VALUE cWIN32OLE_TYPE;
+
 void Init_win32ole_type(void)
 {
     cWIN32OLE_TYPE = rb_define_class("WIN32OLE_TYPE", rb_cObject);

ext/win32ole/win32ole_type.h

@@ -1,6 +1,6 @@
 #ifndef WIN32OLE_TYPE_H
 #define WIN32OLE_TYPE_H 1
-VALUE cWIN32OLE_TYPE;
+extern VALUE cWIN32OLE_TYPE;
 VALUE create_win32ole_type(ITypeInfo *pTypeInfo, VALUE name);
 ITypeInfo *itypeinfo(VALUE self);
 VALUE ole_type_from_itypeinfo(ITypeInfo *pTypeInfo);

ext/win32ole/win32ole_typelib.c

@@ -822,6 +822,8 @@ foletypelib_inspect(VALUE self)
     return default_inspect(self, "WIN32OLE_TYPELIB");
 }
 
+VALUE cWIN32OLE_TYPELIB;
+
 void
 Init_win32ole_typelib(void)
 {

ext/win32ole/win32ole_typelib.h

@@ -1,7 +1,7 @@
 #ifndef WIN32OLE_TYPELIB_H
 #define WIN32OLE_TYPELIB_H 1
 
-VALUE cWIN32OLE_TYPELIB;
+extern VALUE cWIN32OLE_TYPELIB;
 
 void Init_win32ole_typelib(void);
 ITypeLib * itypelib(VALUE self);

ext/win32ole/win32ole_variable.c

@@ -365,6 +365,8 @@ folevariable_inspect(VALUE self)
     return make_inspect("WIN32OLE_VARIABLE", detail);
 }
 
+VALUE cWIN32OLE_VARIABLE;
+
 void Init_win32ole_variable(void)
 {
     cWIN32OLE_VARIABLE = rb_define_class("WIN32OLE_VARIABLE", rb_cObject);

ext/win32ole/win32ole_variable.h

@@ -1,7 +1,7 @@
 #ifndef WIN32OLE_VARIABLE_H
 #define WIN32OLE_VARIABLE_H 1
 
-VALUE cWIN32OLE_VARIABLE;
+extern VALUE cWIN32OLE_VARIABLE;
 VALUE create_win32ole_variable(ITypeInfo *pTypeInfo, UINT index, VALUE name);
 void Init_win32ole_variable(void);
 

ext/win32ole/win32ole_variant.c

@@ -689,6 +689,8 @@ ole_variant2variant(VALUE val, VARIANT *var)
     VariantCopy(var, &(pvar->var));
 }
 
+VALUE cWIN32OLE_VARIANT;
+
 void
 Init_win32ole_variant(void)
 {

ext/win32ole/win32ole_variant.h

@@ -1,7 +1,7 @@
 #ifndef WIN32OLE_VARIANT_H
 #define WIN32OLE_VARIANT_H 1
 
-VALUE cWIN32OLE_VARIANT;
+extern VALUE cWIN32OLE_VARIANT;
 void ole_variant2variant(VALUE val, VARIANT *var);
 void Init_win32ole_variant(void);
 

ext/win32ole/win32ole_variant_m.c

@@ -1,5 +1,7 @@
 #include "win32ole.h"
 
+VALUE mWIN32OLE_VARIANT;
+
 void Init_win32ole_variant_m(void)
 {
     /*

ext/win32ole/win32ole_variant_m.h

@@ -1,7 +1,7 @@
 #ifndef WIN32OLE_VARIANT_M_H
 #define WIN32OLE_VARIANT_M_H 1
 
-VALUE mWIN32OLE_VARIANT;
+extern VALUE mWIN32OLE_VARIANT;
 void Init_win32ole_variant_m(void);
 
 #endif