source: src/tests/except-2.c@ c65a80b

// New draft of exception tests.


#include <string.h>

// Local Exception Types and manual vtable types.
#define BASE_EXCEPT __cfaehm__base_exception_t
#define TABLE(name) name##_vtable
#define INSTANCE(name) _##name##_vtable_instance
#define TRIVIAL_EXCEPTION(name) \
struct name; \
struct TABLE(name) { \
        struct __cfaehm__base_exception_t_vtable const * parent; \
        size_t size; \
        void (*copy)(name *this, name * other); \
        void (*free)(name *this); \
        const char * (*msg)(name *this); \
}; \
extern TABLE(name) INSTANCE(name); \
struct name { \
        struct TABLE(name) const * virtual_table; \
}; \
const char * name##_msg(name * this) { \
        return #name; \
} \
void name##_copy(name * this, name * other) { \
        this->virtual_table = other->virtual_table; \
} \
TABLE(name) INSTANCE(name) @= { \
        .parent : &INSTANCE(__cfaehm__base_exception_t), \
        .size : sizeof(name), .copy : name##_copy, \
        .free : ^?{}, .msg : name##_msg \
}; \
void ?{}(name * this) { \
        this->virtual_table = &INSTANCE(name); \
}
TRIVIAL_EXCEPTION(yin)
TRIVIAL_EXCEPTION(yang)

struct num_error;
struct num_error_vtable {
        struct exception_t_vtable const * parent;
        size_t size;
        void (*copy)(num_error *this, num_error * other);
        void (*free)(num_error *this);
        const char * (*msg)(num_error *this);
        int (*code)(num_error *this);
};
extern num_error_vtable INSTANCE(num_error);
struct num_error {
        struct num_error_vtable const * virtual_table;
        char * msg;
        int num;
};
void num_error_msg(num_error * this) {
        if ( ! this->msg ) {
                const char * base = "Num Error with code: X";
                this->msg = strdup( base );
        }
        this->msg[21] = '0' + this->num;
        return this->msg;
}
void ?{}(num_error * this, int num) {
        this->virtual_table = &_num_error_vtable_instance;
        this->msg = 0;
        this->num = num;
}
void ?{}(num_error * this, num_error * other) {
        this->virtual_table = other->virtual_table;
        this->msg = 0;
        this->num = other->num;
}
void ^?{}(num_error * this) {
        if( this->msg ) free( this->msg );
}
int num_error_code( num_error * this ) {
        return this->num;
}
num_error_vtable _num_error_vtable_instance @= {
        &___cfaehm__base_exception_t_vtable_instance,
        sizeof(num_error), ?{}, ^?{},
        num_error_msg, num_error_code
};


// Test simple throwing, matching and catching.
void throw_catch() {
        try {
                yin black;
                throw (BASE_EXCEPT *)&black;
        } catch( yin * error ) {
                printf("throw yin caught.\n");
        }

        try {
                yang white;
                throwResume (BASE_EXCEPT *)&white;
                printf("> throwResume returned.\n");
        } catchResume( yang * error ) {
                printf("throwResume yang caught <");
        }

        /* Conditional catches are still a work in progress.
        try {
                num_error x = { 2 };
                throw (struct exception_t *)&x;
        }
        catch (num_error * error0 ; 3 == error0->virtual_table->code( error0 ) ) {
                printf("exception at %p\n", error0 );
                printf("Should not be printed.\n");
        }
        catch (num_error * error1 ; 2 == error1->virtual_table->code( error1 ) ) {
                printf("Should be printed.\n");
        }*/
}

int main (int argc, char * argv[]) {
        throw_catch();
        return 0;
}