exception.h

#ifndef EXCEPTION_H

#define EXCEPTION_H

#include <limits.h>

#include <stdbool.h>

#include <string.h>

#include <setjmp.h>

#define BEFORE_AND_AFTER_BLOCK(X,BEFORE,AFTER,T) \

  for( struct{bool BAAB_V;T;}X={.BAAB_V=true}; X.BAAB_V&&(EX_UNPACK BEFORE); X.BAAB_V=(EX_UNPACK AFTER) )

#define EX_UNPACK(...) __VA_ARGS__

#define try BEFORE_AND_AFTER_BLOCK( ex_baab, (beginTry(&ex_baab.ex_ejs),!setjmp(ex_baab.ex_ejs.current)||endTry(&ex_baab.ex_ejs)), (endTry(&ex_baab.ex_ejs),false), struct exceptionJmpStorage ex_ejs )

#define catch( T, VAR ) \

  for( struct T##_type* VAR=(struct T##_type*)exception; \

  catchMatch( T ); exception = (void*)1 )

#define finally( VAR ) for( struct exception* VAR=exception; exception&&exception!=(void*)1; (void)VAR,exception=0 )

#define throw(T,V) do { \

  lastException.T = (struct T##_type){ EX_UNPACK V }; \

  exception = (void*)&lastException; \

  exception->type = T; \

  longjmp( *exception_jmp_buf, 1 );\

} while(0)

#define rethrow() longjmp( *exception_jmp_buf, 1 )

struct exception;

struct exception {

  int type;

};

struct exceptionJmpStorage {

  jmp_buf* last;

  jmp_buf current;

};

extern union anyException lastException;

extern struct exception* exception;

extern jmp_buf* exception_jmp_buf;

void beginTry( struct exceptionJmpStorage* );

bool endTry( struct exceptionJmpStorage* );

bool catchMatch( int type );

bool finallyBefore( void );

void finallyAfter( void );

#endif