Introduced running_machine::compose_saveload_filename() function to convert a filename (for state save/load) to a fully qualified path

src/emu/machine.cpp

@@ -549,6 +549,39 @@ std::string running_machine::get_statename(const char *option) const
 	return statename_str;
 }
 
+
+//-------------------------------------------------
+//  compose_saveload_filename - composes a filename
+//  for state loading/saving
+//-------------------------------------------------
+
+std::string running_machine::compose_saveload_filename(const char *filename, const char **searchpath)
+{
+	std::string result;
+
+	// is this an absolute path?
+	if (osd_is_absolute_path(filename))
+	{
+		// if so, this is easy
+		if (searchpath != nullptr)
+			*searchpath = nullptr;
+		result = filename;
+	}
+	else
+	{
+		// this is a relative path; first specify the search path
+		if (searchpath != nullptr)
+			*searchpath = options().state_directory();
+
+		// take into account the statename option
+		const char *stateopt = options().state_name();
+		std::string statename = get_statename(stateopt);
+		result = string_format("%s%s%s.sta", statename, PATH_SEPARATOR, filename);
+	}
+	return result;
+}
+
+
 //-------------------------------------------------
 //  set_saveload_filename - specifies the filename
 //  for state loading/saving
@@ -556,20 +589,8 @@ std::string running_machine::get_statename(const char *option) const
 
 void running_machine::set_saveload_filename(const char *filename)
 {
-	// free any existing request and allocate a copy of the requested name
+	// compose the save/load filename and persist it
-	if (osd_is_absolute_path(filename))
+	m_saveload_pending_file = compose_saveload_filename(filename, &m_saveload_searchpath);
-	{
-		m_saveload_searchpath = nullptr;
-		m_saveload_pending_file.assign(filename);
-	}
-	else
-	{
-		m_saveload_searchpath = options().state_directory();
-		// take into account the statename option
-		const char *stateopt = options().state_name();
-		std::string statename = get_statename(stateopt);
-		m_saveload_pending_file = string_format("%s%s%s.sta", statename, PATH_SEPARATOR, filename);
-	}
 }
 
 

src/emu/machine.h

@@ -234,6 +234,7 @@ public:
 	void strlog(const char *str) const;
 	UINT32 rand();
 	const char *describe_context();
+	std::string compose_saveload_filename(const char *base_filename, const char **searchpath = nullptr);
 
 	// CPU information
 	cpu_device *            firstcpu;           // first CPU