Initial commit

include/except.h

@@ -0,0 +1,82 @@
+#ifndef EXCEPT_INCLUDED
+#define EXCEPT_INCLUDED
+
+#include <setjmp.h>
+
+#define UNUSED(x) (void)(x)
+
+struct Exception {
+	const char *reason;
+};
+typedef struct Exception Exception;
+
+struct ExceptFrame {
+	struct ExceptFrame *prev;   // Exception Stack
+	jmp_buf env;                // Enviroment Buffer
+    const char *file;           // Exception File
+	int line;                   // Exception Line
+	const Exception *exception; // Exception Reason
+};
+typedef struct ExceptFrame ExceptFrame;
+
+// Exception States 
+enum { EXCEPT_ENTERED=0, EXCEPT_RAISED, EXCEPT_HANDLED, EXCEPT_FINALIZED};
+
+void except_raise(const Exception *e, const char *file,int line); // Raise exceptions
+
+// External declarations 
+extern ExceptFrame *except_stack; // Global exception stack
+extern const Exception assert_failed; // Forward declaration for assert. 
+extern void asserted(int e);
+
+#ifdef NDEBUG
+#define ASSERTED(e) ((void)0)
+#else
+#define ASSERTED(e) ((void)((e)||(RAISE(assert_failed),0)))
+#endif
+
+// Raise an Exception.
+#define RAISE(e) except_raise(&(e), __FILE__, __LINE__)
+
+// Reraise the currect exception.
+#define RERAISE except_raise(except_frame.exception, \
+	except_frame.file, except_frame.line)
+
+// Switch to the previous exception frame and return.
+#define RETURN switch (except_stack = except_stack->prev,0) default: return
+
+// Start a try block.
+#define TRY do { \
+	volatile int except_flag; \
+	ExceptFrame except_frame; \
+	except_frame.prev = except_stack; \
+	except_stack = &except_frame;  \
+	except_flag = setjmp(except_frame.env); \
+	if (except_flag == EXCEPT_ENTERED) {
+
+// Handle specific example.
+#define EXCEPT(e) \
+		if (except_flag == EXCEPT_ENTERED) except_stack = except_stack->prev; \
+	} else if (except_frame.exception == &(e)) { \
+		except_flag = EXCEPT_HANDLED;
+
+// Catch all other exceptions.        
+#define ELSE \
+		if (except_flag == EXCEPT_ENTERED) except_stack = except_stack->prev; \
+	} else { \
+		except_flag = EXCEPT_HANDLED;
+
+// Execute finalization code.        
+#define FINALLY \
+		if (except_flag == EXCEPT_ENTERED) except_stack = except_stack->prev; \
+	} { \
+		if (except_flag == EXCEPT_ENTERED) \
+			except_flag = EXCEPT_FINALIZED;
+
+// End Try block.         
+#define END_TRY \
+		if (except_flag == EXCEPT_ENTERED) except_stack = except_stack->prev; \
+		} if (except_flag == EXCEPT_RAISED) RERAISE; \
+} while (0)
+
+#endif