trycatch/trycatch.h at main · bruneo32/trycatch · GitHub

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#ifndef TRYCATCH_H
#define TRYCATCH_H

#include <setjmp.h>
#include <stdlib.h>

typedef struct Exception {
    size_t  code;
    void   *data;
} Exception;

typedef struct ExceptionContext {
    jmp_buf env;
    struct ExceptionContext* prev;
    Exception exception;
} ExceptionContext;

#ifndef EXCEPTION_CONTEXT
extern ExceptionContext *___try_catch_exception_context;
#define EXCEPTION_CONTEXT ___try_catch_exception_context
#endif

#define TCH_CONCAT(a,b) a##b
#define TCH_UNIQUE_NAME(a,b) TCH_CONCAT(a,b)

#define _pop_exception_context _pop_exception_context_impl(TCH_UNIQUE_NAME(_ctx_prev_, __COUNTER__))
#define _pop_exception_context_impl(__varname__)           \
    ({                                                     \
        ExceptionContext *__varname__ = EXCEPTION_CONTEXT; \
        EXCEPTION_CONTEXT = EXCEPTION_CONTEXT->prev;       \
        __varname__;                                       \
    })

#define _push_exception_context _push_exception_context_impl(TCH_UNIQUE_NAME(_ctx_, __COUNTER__))
#define _push_exception_context_impl(__varname__)             \
    ({                                                        \
        volatile ExceptionContext __varname__;                \
        __varname__.prev = EXCEPTION_CONTEXT;                 \
        EXCEPTION_CONTEXT = (ExceptionContext *)&__varname__; \
    })

#define try  \
    if ((_push_exception_context, \
         EXCEPTION_CONTEXT->exception.code = setjmp(EXCEPTION_CONTEXT->env)) == 0)

#define catch(decl_) catch_impl(decl_, TCH_UNIQUE_NAME(__once_, __COUNTER__))
#define catch_impl(decl_, __varname__)                                      \
    else for (char __varname__ = 1; __varname__;)                           \
         for (__attribute__((unused)) decl_ = EXCEPTION_CONTEXT->exception; \
              __varname__ && _pop_exception_context; __varname__ = 0)

#define finally ;

#define throw(x_, d_)                             \
    ({                                            \
        EXCEPTION_CONTEXT->exception.data = (d_); \
        longjmp(EXCEPTION_CONTEXT->env, (x_));    \
        EXCEPTION_CONTEXT;                        \
    })

#endif  // TRYCATCH_H