Add doxygen docs

include/sta/lang.hpp

@@ -1,34 +1,66 @@
 /**
+ * @file
  * @brief Helper for useful compiler features.
  */
 #ifndef STA_LANG_HPP
 #define STA_LANG_HPP
 
+/**
+ * @defgroup staCoreLang Lang
+ * @ingroup staCore
+ * @brief Compiler instructions.
+ * @{
+ */
 
+
+/**
+ * @brief Assembler instruction.
+ */
 #ifndef STA_ASM
 #  define STA_ASM 			__asm
 #endif // STA_ASM
 
+/**
+ * @brief Mark as deprecated.
+ */
 #ifndef STA_DEPRECATED
 #  define STA_DEPRECATED	__attribute__((deprecated))
 #endif // STA_DEPRECATED
 
+/**
+ * @brief Mark as weak definition.
+ */
 #ifndef STA_WEAK
 #  define STA_WEAK 			__attribute__((weak))
 #endif // STA_WEAK
 
+
+/**
+ * @brief Mark as field w/o added padding.
+ */
 #ifndef STA_PACKED
 #  define STA_PACKED		__attribute__((packed))
 #endif // STA_PACKED
 
+/**
+ * @brief Mark as struct w/o added padding.
+ */
 #ifndef STA_PACKED_STRUCT
 #  define STA_PACKED_STRUCT	struct STA_PACKED
 #endif // STA_PACKED_STRUCT
 
+/**
+ * @brief Mark as union w/o added padding.
+ */
 #ifndef STA_PACKED_UNION
 #  define STA_PACKED_UNION	union STA_PACKED
 #endif // STA_PACKED_UNION
 
+/**
+ * @brief Add breakpoint.
+ *
+ * @param value Additional uint16_t data for debugger
+ */
 #ifndef STA_BKPT
 #  define STA_BKPT(value)	STA_ASM volatile ("bkpt "#value)
 #endif // STA_BKPT
@@ -37,17 +69,48 @@
 // TODO Check for GCC
 
 /**
- * @brief Helper for silencing compiler warnings in unreachable code locations.
+ * @brief Silencing compiler warnings in unreachable code locations.
  *
- * Example: Default of switch handling all cases of enum class
+ * Example:
+ * @code
+ * enum class E { A };
+ *
+ * E val = A;
+ *
+ * switch (val)
+ * {
+ * case E::A:
+ *     break;
+ *
+ * default:
+ *     // All enum values already handled
+ *     STA_UNREACHABLE();
+ * }
+ * @endcode
  */
 #ifndef STA_UNREACHABLE
 #  define STA_UNREACHABLE() __builtin_unreachable()
 #endif // !STA_UNREACHABLE
 
+/**
+ * @brief Silencing compiler warnings for intended switch case fallthrough.
+ *
+ * Example:
+ * @code
+ * switch (val)
+ * {
+ * case A: STA_FALLTHROUGH();
+ * case B:
+ *     do();
+ *     break;
+ * }
+ * @endcode
+ */
 #ifndef STA_FALLTRHOUGH
 #  define STA_FALLTHROUGH() __attribute__((fallthrough))
 #endif // !STA_FALLTRHOUGH
 
 
+/** @} */
+
 #endif // STA_LANG_HPP