[#170] Make plugin interface functions static.

Before this change, it was possible for other rule engine plugins to
invoke the python rule engine plugin's interface functions. This is very
bad because it can lead to sibling plugins not operating correctly
and/or a broken server.

Marking the interface functions as static makes them private to the
implementation of the plugin. This means no other rule engine plugin
will be able to invoke the python rule engine plugin's interface
functions.

Author: korydraughn

src/main.cpp

@@ -340,7 +340,7 @@ namespace
 	}
 } // anonymous namespace
 
-irods::error start(irods::default_re_ctx&, const std::string& _instance_name)
+static irods::error start(irods::default_re_ctx&, const std::string& _instance_name)
 {
 	try {
 #if PY_VERSION_HEX < 0x03000000
@@ -449,15 +449,15 @@ irods::error start(irods::default_re_ctx&, const std::string& _instance_name)
 	return ERROR(SYS_INVALID_INPUT_PARAM, msg.str());
 }
 
-irods::error stop(irods::default_re_ctx&, const std::string&)
+static irods::error stop(irods::default_re_ctx&, const std::string&)
 {
 	// Boost.Python's documentation advises not to call Py_Finalize
 	// https://www.boost.org/doc/libs/1_78_0/libs/python/doc/html/tutorial/tutorial/embedding.html
 	//Py_Finalize();
 	return SUCCESS();
 }
 
-irods::error rule_exists(const irods::default_re_ctx&, const std::string& rule_name, bool& _return)
+static irods::error rule_exists(const irods::default_re_ctx&, const std::string& rule_name, bool& _return)
 {
 	_return = false;
 	try {
@@ -484,7 +484,7 @@ irods::error rule_exists(const irods::default_re_ctx&, const std::string& rule_n
 	return SUCCESS();
 }
 
-irods::error list_rules(const irods::default_re_ctx&, std::vector<std::string>& rule_vec)
+static irods::error list_rules(const irods::default_re_ctx&, std::vector<std::string>& rule_vec)
 {
 	try {
 		std::lock_guard<std::recursive_mutex> lock{python_mutex};
@@ -544,10 +544,10 @@ irods::error list_rules(const irods::default_re_ctx&, std::vector<std::string>&
 	return SUCCESS();
 }
 
-irods::error exec_rule(const irods::default_re_ctx&,
-                       const std::string& rule_name,
-                       std::list<boost::any>& rule_arguments_cpp,
-                       irods::callback effect_handler)
+static irods::error exec_rule(const irods::default_re_ctx&,
+                              const std::string& rule_name,
+                              std::list<boost::any>& rule_arguments_cpp,
+                              irods::callback effect_handler)
 {
 	try {
 		std::lock_guard<std::recursive_mutex> lock{python_mutex};
@@ -627,11 +627,11 @@ irods::error exec_rule(const irods::default_re_ctx&,
 }
 
 //irule
-irods::error exec_rule_text(const irods::default_re_ctx&,
-                            const std::string& rule_text,
-                            msParamArray_t* ms_params,
-                            const std::string& out_desc,
-                            irods::callback effect_handler)
+static irods::error exec_rule_text(const irods::default_re_ctx&,
+                                   const std::string& rule_text,
+                                   msParamArray_t* ms_params,
+                                   const std::string& out_desc,
+                                   irods::callback effect_handler)
 {
 	// Because Python is not sandboxed, need to restrict irule to admin users only
 	const auto rei = get_rei_from_effect_handler(effect_handler);
@@ -807,10 +807,10 @@ irods::error exec_rule_text(const irods::default_re_ctx&,
 }
 
 //delay execution
-irods::error exec_rule_expression(irods::default_re_ctx&,
-                                  const std::string& rule_text,
-                                  msParamArray_t* ms_params,
-                                  irods::callback effect_handler)
+static irods::error exec_rule_expression(irods::default_re_ctx&,
+                                         const std::string& rule_text,
+                                         msParamArray_t* ms_params,
+                                         irods::callback effect_handler)
 {
 	try {
 		std::lock_guard<std::recursive_mutex> lock{python_mutex};