fix: enforce const-correctness in indexed_vector

Signed-off-by: Kevin Vu <vietcgi@gmail.com>

Author: vietcgi

userspace/engine/indexed_vector.h

@@ -87,9 +87,32 @@ class indexed_vector {
 	    \brief Returns a pointer to the element at the given numeric index,
 	    or nullptr if no element exists at the given index.
 	*/
-	virtual inline T* at(size_t id) const {
+	virtual inline const T* at(size_t id) const {
 		if(id < m_entries.size()) {
-			return (T* const)&m_entries[id];
+			return &m_entries[id];
+		}
+		return nullptr;
+	}
+
+	/*!
+	    \brief Returns a pointer to the element at the given numeric index,
+	    or nullptr if no element exists at the given index.
+	*/
+	virtual inline T* at(size_t id) {
+		if(id < m_entries.size()) {
+			return &m_entries[id];
+		}
+		return nullptr;
+	}
+
+	/*!
+	    \brief Returns a pointer to the element at the given string index,
+	    or nullptr if no element exists at the given index.
+	*/
+	virtual inline const T* at(const std::string& index) const {
+		auto it = m_index.find(index);
+		if(it != m_index.end()) {
+			return at(it->second);
 		}
 		return nullptr;
 	}
@@ -98,7 +121,7 @@ class indexed_vector {
 	    \brief Returns a pointer to the element at the given string index,
 	    or nullptr if no element exists at the given index.
 	*/
-	virtual inline T* at(const std::string& index) const {
+	virtual inline T* at(const std::string& index) {
 		auto it = m_index.find(index);
 		if(it != m_index.end()) {
 			return at(it->second);

userspace/engine/rule_loader_compiler.cpp

@@ -153,17 +153,17 @@ static void build_rule_exception_infos(
 	}
 }
 
-static inline rule_loader::list_info* list_info_from_name(const rule_loader::collector& c,
-                                                          const std::string& name) {
+static inline const rule_loader::list_info* list_info_from_name(const rule_loader::collector& c,
+                                                                const std::string& name) {
 	auto ret = c.lists().at(name);
 	if(!ret) {
 		throw falco_exception("can't find internal list info at name: " + name);
 	}
 	return ret;
 }
 
-static inline rule_loader::macro_info* macro_info_from_name(const rule_loader::collector& c,
-                                                            const std::string& name) {
+static inline const rule_loader::macro_info* macro_info_from_name(const rule_loader::collector& c,
+                                                                   const std::string& name) {
 	auto ret = c.macros().at(name);
 	if(!ret) {
 		throw falco_exception("can't find internal macro info at name: " + name);