[p5sagit/p5-mst-13.2.git] / scope.h

#define SAVEt_ITEM		0
#define SAVEt_SV		1
#define SAVEt_AV		2
#define SAVEt_HV		3
#define SAVEt_INT		4
#define SAVEt_LONG		5
#define SAVEt_I32		6
#define SAVEt_IV		7
#define SAVEt_SPTR		8
#define SAVEt_APTR		9
#define SAVEt_HPTR		10
#define SAVEt_PPTR		11
#define SAVEt_NSTAB		12
#define SAVEt_SVREF		13
#define SAVEt_GP		14
#define SAVEt_FREESV		15
#define SAVEt_FREEOP		16
#define SAVEt_FREEPV		17
#define SAVEt_CLEARSV		18
#define SAVEt_DELETE		19
#define SAVEt_DESTRUCTOR	20
#define SAVEt_REGCONTEXT	21
#define SAVEt_STACK_POS		22
#define SAVEt_I16		23
#define SAVEt_AELEM		24
#define SAVEt_HELEM		25
#define SAVEt_OP		26
#define SAVEt_HINTS		27
#define SAVEt_ALLOC		28
#define SAVEt_GENERIC_SVREF	29
#define SAVEt_DESTRUCTOR_X	30

#define SSCHECK(need) if (PL_savestack_ix + need > PL_savestack_max) savestack_grow()
#define SSPUSHINT(i) (PL_savestack[PL_savestack_ix++].any_i32 = (I32)(i))
#define SSPUSHLONG(i) (PL_savestack[PL_savestack_ix++].any_long = (long)(i))
#define SSPUSHIV(i) (PL_savestack[PL_savestack_ix++].any_iv = (IV)(i))
#define SSPUSHPTR(p) (PL_savestack[PL_savestack_ix++].any_ptr = (void*)(p))
#define SSPUSHDPTR(p) (PL_savestack[PL_savestack_ix++].any_dptr = (p))
#define SSPUSHDXPTR(p) (PL_savestack[PL_savestack_ix++].any_dxptr = (p))
#define SSPOPINT (PL_savestack[--PL_savestack_ix].any_i32)
#define SSPOPLONG (PL_savestack[--PL_savestack_ix].any_long)
#define SSPOPIV (PL_savestack[--PL_savestack_ix].any_iv)
#define SSPOPPTR (PL_savestack[--PL_savestack_ix].any_ptr)
#define SSPOPDPTR (PL_savestack[--PL_savestack_ix].any_dptr)
#define SSPOPDXPTR (PL_savestack[--PL_savestack_ix].any_dxptr)

#define SAVETMPS save_int((int*)&PL_tmps_floor), PL_tmps_floor = PL_tmps_ix
#define FREETMPS if (PL_tmps_ix > PL_tmps_floor) free_tmps()

#ifdef DEBUGGING
#define ENTER							\
    STMT_START {						\
	push_scope();						\
	DEBUG_l(WITH_THR(Perl_deb(aTHX_ "ENTER scope %ld at %s:%d\n",	\
		    PL_scopestack_ix, __FILE__, __LINE__)));	\
    } STMT_END
#define LEAVE							\
    STMT_START {						\
	DEBUG_l(WITH_THR(Perl_deb(aTHX_ "LEAVE scope %ld at %s:%d\n",	\
		    PL_scopestack_ix, __FILE__, __LINE__)));	\
	pop_scope();						\
    } STMT_END
#else
#define ENTER push_scope()
#define LEAVE pop_scope()
#endif
#define LEAVE_SCOPE(old) if (PL_savestack_ix > old) leave_scope(old)

/*
 * Not using SOFT_CAST on SAVESPTR, SAVEGENERICSV and SAVEFREESV
 * because these are used for several kinds of pointer values
 */
#define SAVEI16(i)	save_I16(SOFT_CAST(I16*)&(i))
#define SAVEI32(i)	save_I32(SOFT_CAST(I32*)&(i))
#define SAVEINT(i)	save_int(SOFT_CAST(int*)&(i))
#define SAVEIV(i)	save_iv(SOFT_CAST(IV*)&(i))
#define SAVELONG(l)	save_long(SOFT_CAST(long*)&(l))
#define SAVESPTR(s)	save_sptr((SV**)&(s))
#define SAVEPPTR(s)	save_pptr(SOFT_CAST(char**)&(s))
#define SAVEFREESV(s)	save_freesv((SV*)(s))
#define SAVEFREEOP(o)	save_freeop(SOFT_CAST(OP*)(o))
#define SAVEFREEPV(p)	save_freepv(SOFT_CAST(char*)(p))
#define SAVECLEARSV(sv)	save_clearsv(SOFT_CAST(SV**)&(sv))
#define SAVEGENERICSV(s)	save_generic_svref((SV**)&(s))
#define SAVEDELETE(h,k,l) \
	  save_delete(SOFT_CAST(HV*)(h), SOFT_CAST(char*)(k), (I32)(l))
#define SAVEDESTRUCTOR(f,p) \
	  save_destructor((DESTRUCTORFUNC_NOCONTEXT_t)(f), SOFT_CAST(void*)(p))

#define SAVEDESTRUCTOR_X(f,p) \
	  save_destructor_x((DESTRUCTORFUNC_t)(f), SOFT_CAST(void*)(p))

#define SAVESTACK_POS() \
    STMT_START {				\
	SSCHECK(2);				\
	SSPUSHINT(PL_stack_sp - PL_stack_base);	\
	SSPUSHINT(SAVEt_STACK_POS);		\
    } STMT_END

#define SAVEOP()	save_op()

#define SAVEHINTS() \
    STMT_START {				\
	if (PL_hints & HINT_LOCALIZE_HH)	\
	    save_hints();			\
	else {					\
	    SSCHECK(2);				\
	    SSPUSHINT(PL_hints);		\
	    SSPUSHINT(SAVEt_HINTS);		\
	}					\
    } STMT_END

#ifdef USE_ITHREADS
#  define SAVECOPFILE(cop)	SAVEPPTR(CopFILE(cop))
#else
#  define SAVECOPFILE(cop)	SAVESPTR(CopFILEGV(cop))
#endif

#define SAVECOPLINE(cop)	SAVEI16(CopLINE(cop))

/* SSNEW() temporarily allocates a specified number of bytes of data on the
 * savestack.  It returns an integer index into the savestack, because a
 * pointer would get broken if the savestack is moved on reallocation.
 * SSNEWa() works like SSNEW(), but also aligns the data to the specified
 * number of bytes.  MEM_ALIGNBYTES is perhaps the most useful.  The
 * alignment will be preserved therough savestack reallocation *only* if
 * realloc returns data aligned to a size divisible by `align'!
 *
 * SSPTR() converts the index returned by SSNEW/SSNEWa() into a pointer.
 */

#define SSNEW(size)             save_alloc(size, 0)
#define SSNEWa(size,align)	save_alloc(size, \
    (align - ((int)((caddr_t)&PL_savestack[PL_savestack_ix]) % align)) % align)

#define SSPTR(off,type)         ((type) ((char*)PL_savestack + off))

/* A jmpenv packages the state required to perform a proper non-local jump.
 * Note that there is a start_env initialized when perl starts, and top_env
 * points to this initially, so top_env should always be non-null.
 *
 * Existence of a non-null top_env->je_prev implies it is valid to call
 * longjmp() at that runlevel (we make sure start_env.je_prev is always
 * null to ensure this).
 *
 * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
 * establish a local jmpenv to handle exception traps.  Care must be taken
 * to restore the previous value of je_mustcatch before exiting the
 * stack frame iff JMPENV_PUSH was not called in that stack frame.
 * GSAR 97-03-27
 */

struct jmpenv {
    struct jmpenv *	je_prev;
    Sigjmp_buf		je_buf;		/* only for use if !je_throw */
    int			je_ret;		/* last exception thrown */
    bool		je_mustcatch;	/* need to call longjmp()? */
    void		(*je_throw)(int v); /* last for bincompat */
    bool		je_noset;	/* no need for setjmp() */
};

typedef struct jmpenv JMPENV;

/*
 * Function that catches/throws, and its callback for the
 *  body of protected processing.
 */
typedef void *(CPERLscope(*protect_body_t)) (pTHX_ va_list);
typedef void *(CPERLscope(*protect_proc_t)) (pTHX_ volatile JMPENV *pcur_env,
					     int *, protect_body_t, ...);

/*
 * How to build the first jmpenv.
 *
 * top_env needs to be non-zero. It points to an area
 * in which longjmp() stuff is stored, as C callstack
 * info there at least is thread specific this has to
 * be per-thread. Otherwise a 'die' in a thread gives
 * that thread the C stack of last thread to do an eval {}!
 */

#define JMPENV_BOOTSTRAP \
    STMT_START {				\
	PL_start_env.je_prev = NULL;		\
	PL_start_env.je_throw = NULL;		\
	PL_start_env.je_ret = -1;		\
	PL_start_env.je_mustcatch = TRUE;	\
	PL_start_env.je_noset = 0;		\
	PL_top_env = &PL_start_env;		\
    } STMT_END

#ifdef OP_IN_REGISTER
#define OP_REG_TO_MEM	PL_opsave = op
#define OP_MEM_TO_REG	op = PL_opsave
#else
#define OP_REG_TO_MEM	NOOP
#define OP_MEM_TO_REG	NOOP
#endif

/*
 * These exception-handling macros are split up to
 * ease integration with C++ exceptions.
 *
 * To use C++ try+catch to catch Perl exceptions, an extension author
 * needs to first write an extern "C" function to throw an appropriate
 * exception object; typically it will be or contain an integer,
 * because Perl's internals use integers to track exception types:
 *    extern "C" { static void thrower(int i) { throw i; } }
 *
 * Then (as shown below) the author needs to use, not the simple
 * JMPENV_PUSH, but several of its constitutent macros, to arrange for
 * the Perl internals to call thrower() rather than longjmp() to
 * report exceptions:
 *
 *    dJMPENV;
 *    JMPENV_PUSH_INIT(thrower);
 *    try {
 *        ... stuff that may throw exceptions ...
 *    }
 *    catch (int why) {  // or whatever matches thrower()
 *        JMPENV_POST_CATCH;
 *        EXCEPT_SET(why);
 *        switch (why) {
 *          ... // handle various Perl exception codes
 *        }
 *    }
 *    JMPENV_POP;  // don't forget this!
 */

#define dJMPENV	JMPENV cur_env;	\
		volatile JMPENV *pcur_env = ((cur_env.je_noset = 0),&cur_env)

#define JMPENV_PUSH_INIT_ENV(ce,THROWFUNC) \
    STMT_START {					\
	(ce).je_throw = (THROWFUNC);			\
	(ce).je_ret = -1;				\
	(ce).je_mustcatch = FALSE;			\
	(ce).je_prev = PL_top_env;			\
	PL_top_env = &(ce);				\
	OP_REG_TO_MEM;					\
    } STMT_END

#define JMPENV_PUSH_INIT(THROWFUNC) JMPENV_PUSH_INIT_ENV(*(JMPENV*)pcur_env,THROWFUNC) 

#define JMPENV_POST_CATCH_ENV(ce) \
    STMT_START {					\
	OP_MEM_TO_REG;					\
	PL_top_env = &(ce);				\
    } STMT_END

#define JMPENV_POST_CATCH JMPENV_POST_CATCH_ENV(*(JMPENV*)pcur_env)


#define JMPENV_PUSH_ENV(ce,v) \
    STMT_START {						\
	if (!(ce).je_noset) {					\
	    JMPENV_PUSH_INIT_ENV(ce,NULL);			\
	    EXCEPT_SET_ENV(ce,PerlProc_setjmp((ce).je_buf, 1));\
	    (ce).je_noset = 1;					\
	}							\
	else							\
	    EXCEPT_SET_ENV(ce,0);				\
	JMPENV_POST_CATCH_ENV(ce);				\
	(v) = EXCEPT_GET_ENV(ce);				\
    } STMT_END

#define JMPENV_PUSH(v) JMPENV_PUSH_ENV(*(JMPENV*)pcur_env,v) 

#define JMPENV_POP_ENV(ce) \
    STMT_START { PL_top_env = (ce).je_prev; } STMT_END

#define JMPENV_POP  JMPENV_POP_ENV(*(JMPENV*)pcur_env) 

#define JMPENV_JUMP(v) \
    STMT_START {						\
	OP_REG_TO_MEM;						\
	if (PL_top_env->je_prev) {				\
	    if (PL_top_env->je_throw)				\
		PL_top_env->je_throw(v);			\
	    else						\
		PerlProc_longjmp(PL_top_env->je_buf, (v));	\
	}							\
	if ((v) == 2)						\
	    PerlProc_exit(STATUS_NATIVE_EXPORT);		\
	PerlIO_printf(Perl_error_log, "panic: top_env\n");	\
	PerlProc_exit(1);					\
    } STMT_END

#define EXCEPT_GET_ENV(ce)	((ce).je_ret)
#define EXCEPT_GET		EXCEPT_GET_ENV(*(JMPENV*)pcur_env)
#define EXCEPT_SET_ENV(ce,v)	((ce).je_ret = (v))
#define EXCEPT_SET(v)		EXCEPT_SET_ENV(*(JMPENV*)pcur_env,v)

#define CATCH_GET		(PL_top_env->je_mustcatch)
#define CATCH_SET(v)		(PL_top_env->je_mustcatch = (v))
Commit	Line	Data
b9d12d37	1	#define SAVEt_ITEM 0
	2	#define SAVEt_SV 1
	3	#define SAVEt_AV 2
	4	#define SAVEt_HV 3
	5	#define SAVEt_INT 4
	6	#define SAVEt_LONG 5
	7	#define SAVEt_I32 6
	8	#define SAVEt_IV 7
	9	#define SAVEt_SPTR 8
	10	#define SAVEt_APTR 9
	11	#define SAVEt_HPTR 10
	12	#define SAVEt_PPTR 11
	13	#define SAVEt_NSTAB 12
	14	#define SAVEt_SVREF 13
	15	#define SAVEt_GP 14
	16	#define SAVEt_FREESV 15
	17	#define SAVEt_FREEOP 16
	18	#define SAVEt_FREEPV 17
	19	#define SAVEt_CLEARSV 18
	20	#define SAVEt_DELETE 19
	21	#define SAVEt_DESTRUCTOR 20
	22	#define SAVEt_REGCONTEXT 21
	23	#define SAVEt_STACK_POS 22
	24	#define SAVEt_I16 23
	25	#define SAVEt_AELEM 24
	26	#define SAVEt_HELEM 25
	27	#define SAVEt_OP 26
	28	#define SAVEt_HINTS 27
	29	#define SAVEt_ALLOC 28
	30	#define SAVEt_GENERIC_SVREF 29
c76ac1ee	31	#define SAVEt_DESTRUCTOR_X 30
79072805	32
3280af22	33	#define SSCHECK(need) if (PL_savestack_ix + need > PL_savestack_max) savestack_grow()
	34	#define SSPUSHINT(i) (PL_savestack[PL_savestack_ix++].any_i32 = (I32)(i))
	35	#define SSPUSHLONG(i) (PL_savestack[PL_savestack_ix++].any_long = (long)(i))
	36	#define SSPUSHIV(i) (PL_savestack[PL_savestack_ix++].any_iv = (IV)(i))
	37	#define SSPUSHPTR(p) (PL_savestack[PL_savestack_ix++].any_ptr = (void*)(p))
	38	#define SSPUSHDPTR(p) (PL_savestack[PL_savestack_ix++].any_dptr = (p))
c76ac1ee	39	#define SSPUSHDXPTR(p) (PL_savestack[PL_savestack_ix++].any_dxptr = (p))
3280af22	40	#define SSPOPINT (PL_savestack[--PL_savestack_ix].any_i32)
	41	#define SSPOPLONG (PL_savestack[--PL_savestack_ix].any_long)
	42	#define SSPOPIV (PL_savestack[--PL_savestack_ix].any_iv)
	43	#define SSPOPPTR (PL_savestack[--PL_savestack_ix].any_ptr)
	44	#define SSPOPDPTR (PL_savestack[--PL_savestack_ix].any_dptr)
c76ac1ee	45	#define SSPOPDXPTR (PL_savestack[--PL_savestack_ix].any_dxptr)
8990e307	46
3280af22	47	#define SAVETMPS save_int((int*)&PL_tmps_floor), PL_tmps_floor = PL_tmps_ix
3280af22	48	#define FREETMPS if (PL_tmps_ix > PL_tmps_floor) free_tmps()
a0d0e21e	49
f46d017c	50	#ifdef DEBUGGING
	51	#define ENTER \
	52	STMT_START { \
	53	push_scope(); \
cea2e8a9	54	DEBUG_l(WITH_THR(Perl_deb(aTHX_ "ENTER scope %ld at %s:%d\n", \
3280af22	55	PL_scopestack_ix, __FILE__, __LINE__))); \
f46d017c	56	} STMT_END
	57	#define LEAVE \
	58	STMT_START { \
cea2e8a9	59	DEBUG_l(WITH_THR(Perl_deb(aTHX_ "LEAVE scope %ld at %s:%d\n", \
3280af22	60	PL_scopestack_ix, __FILE__, __LINE__))); \
f46d017c	61	pop_scope(); \
	62	} STMT_END
	63	#else
a0d0e21e	64	#define ENTER push_scope()
a0d0e21e	65	#define LEAVE pop_scope()
f46d017c	66	#endif
3280af22	67	#define LEAVE_SCOPE(old) if (PL_savestack_ix > old) leave_scope(old)
a0d0e21e	68
55497cff	69	/*
b9d12d37	70	* Not using SOFT_CAST on SAVESPTR, SAVEGENERICSV and SAVEFREESV
55497cff	71	* because these are used for several kinds of pointer values
55497cff	72	*/
4fdae800	73	#define SAVEI16(i) save_I16(SOFT_CAST(I16*)&(i))
	74	#define SAVEI32(i) save_I32(SOFT_CAST(I32*)&(i))
	75	#define SAVEINT(i) save_int(SOFT_CAST(int*)&(i))
	76	#define SAVEIV(i) save_iv(SOFT_CAST(IV*)&(i))
	77	#define SAVELONG(l) save_long(SOFT_CAST(long*)&(l))
55497cff	78	#define SAVESPTR(s) save_sptr((SV**)&(s))
	79	#define SAVEPPTR(s) save_pptr(SOFT_CAST(char**)&(s))
	80	#define SAVEFREESV(s) save_freesv((SV*)(s))
	81	#define SAVEFREEOP(o) save_freeop(SOFT_CAST(OP*)(o))
	82	#define SAVEFREEPV(p) save_freepv(SOFT_CAST(char*)(p))
	83	#define SAVECLEARSV(sv) save_clearsv(SOFT_CAST(SV**)&(sv))
b9d12d37	84	#define SAVEGENERICSV(s) save_generic_svref((SV**)&(s))
55497cff	85	#define SAVEDELETE(h,k,l) \
	86	save_delete(SOFT_CAST(HV)(h), SOFT_CAST(char)(k), (I32)(l))
	87	#define SAVEDESTRUCTOR(f,p) \
c76ac1ee	88	save_destructor((DESTRUCTORFUNC_NOCONTEXT_t)(f), SOFT_CAST(void*)(p))
	89
	90	#define SAVEDESTRUCTOR_X(f,p) \
	91	save_destructor_x((DESTRUCTORFUNC_t)(f), SOFT_CAST(void*)(p))
25eaa213	92
	93	#define SAVESTACK_POS() \
	94	STMT_START { \
	95	SSCHECK(2); \
3280af22	96	SSPUSHINT(PL_stack_sp - PL_stack_base); \
25eaa213	97	SSPUSHINT(SAVEt_STACK_POS); \
	98	} STMT_END
	99
462e5cf6	100	#define SAVEOP() save_op()
25eaa213	101
	102	#define SAVEHINTS() \
	103	STMT_START { \
3280af22	104	if (PL_hints & HINT_LOCALIZE_HH) \
25eaa213	105	save_hints(); \
	106	else { \
	107	SSCHECK(2); \
3280af22	108	SSPUSHINT(PL_hints); \
25eaa213	109	SSPUSHINT(SAVEt_HINTS); \
	110	} \
	111	} STMT_END
a9332b4a	112
57843af0	113	#ifdef USE_ITHREADS
	114	# define SAVECOPFILE(cop) SAVEPPTR(CopFILE(cop))
	115	#else
	116	# define SAVECOPFILE(cop) SAVESPTR(CopFILEGV(cop))
	117	#endif
	118
	119	#define SAVECOPLINE(cop) SAVEI16(CopLINE(cop))
	120
455ece5e	121	/* SSNEW() temporarily allocates a specified number of bytes of data on the
	122	* savestack. It returns an integer index into the savestack, because a
	123	* pointer would get broken if the savestack is moved on reallocation.
	124	* SSNEWa() works like SSNEW(), but also aligns the data to the specified
	125	* number of bytes. MEM_ALIGNBYTES is perhaps the most useful. The
	126	* alignment will be preserved therough savestack reallocation only if
	127	* realloc returns data aligned to a size divisible by `align'!
	128	*
	129	* SSPTR() converts the index returned by SSNEW/SSNEWa() into a pointer.
	130	*/
	131
	132	#define SSNEW(size) save_alloc(size, 0)
	133	#define SSNEWa(size,align) save_alloc(size, \
	134	(align - ((int)((caddr_t)&PL_savestack[PL_savestack_ix]) % align)) % align)
	135
	136	#define SSPTR(off,type) ((type) ((char*)PL_savestack + off))
	137
54310121	138	/* A jmpenv packages the state required to perform a proper non-local jump.
	139	* Note that there is a start_env initialized when perl starts, and top_env
	140	* points to this initially, so top_env should always be non-null.
	141	*
	142	* Existence of a non-null top_env->je_prev implies it is valid to call
6224f72b	143	* longjmp() at that runlevel (we make sure start_env.je_prev is always
6224f72b	144	* null to ensure this).
54310121	145	*
	146	* je_mustcatch, when set at any runlevel to TRUE, means eval ops must
	147	* establish a local jmpenv to handle exception traps. Care must be taken
	148	* to restore the previous value of je_mustcatch before exiting the
	149	* stack frame iff JMPENV_PUSH was not called in that stack frame.
6224f72b	150	* GSAR 97-03-27
54310121	151	*/
	152
	153	struct jmpenv {
	154	struct jmpenv * je_prev;
312caa8e	155	Sigjmp_buf je_buf; /* only for use if !je_throw */
	156	int je_ret; /* last exception thrown */
	157	bool je_mustcatch; /* need to call longjmp()? */
	158	void (je_throw)(int v); / last for bincompat */
db36c5a1	159	bool je_noset; /* no need for setjmp() */
1163b5c4	160	};
1163b5c4	161
6224f72b	162	typedef struct jmpenv JMPENV;
1163b5c4	163
312caa8e	164	/*
	165	* Function that catches/throws, and its callback for the
	166	* body of protected processing.
	167	*/
cea2e8a9	168	typedef void (CPERLscope(protect_body_t)) (pTHX_ va_list);
db36c5a1	169	typedef void (CPERLscope(protect_proc_t)) (pTHX_ volatile JMPENV *pcur_env,
db36c5a1	170	int *, protect_body_t, ...);
312caa8e	171
	172	/*
	173	* How to build the first jmpenv.
	174	*
	175	* top_env needs to be non-zero. It points to an area
	176	* in which longjmp() stuff is stored, as C callstack
	177	* info there at least is thread specific this has to
	178	* be per-thread. Otherwise a 'die' in a thread gives
	179	* that thread the C stack of last thread to do an eval {}!
	180	*/
	181
	182	#define JMPENV_BOOTSTRAP \
	183	STMT_START { \
	184	PL_start_env.je_prev = NULL; \
	185	PL_start_env.je_throw = NULL; \
	186	PL_start_env.je_ret = -1; \
	187	PL_start_env.je_mustcatch = TRUE; \
db36c5a1	188	PL_start_env.je_noset = 0; \
312caa8e	189	PL_top_env = &PL_start_env; \
	190	} STMT_END
	191
462e5cf6	192	#ifdef OP_IN_REGISTER
6b88bc9c	193	#define OP_REG_TO_MEM PL_opsave = op
6b88bc9c	194	#define OP_MEM_TO_REG op = PL_opsave
462e5cf6	195	#else
	196	#define OP_REG_TO_MEM NOOP
	197	#define OP_MEM_TO_REG NOOP
	198	#endif
	199
312caa8e	200	/*
	201	* These exception-handling macros are split up to
	202	* ease integration with C++ exceptions.
	203	*
	204	* To use C++ try+catch to catch Perl exceptions, an extension author
	205	* needs to first write an extern "C" function to throw an appropriate
	206	* exception object; typically it will be or contain an integer,
	207	* because Perl's internals use integers to track exception types:
	208	* extern "C" { static void thrower(int i) { throw i; } }
	209	*
	210	* Then (as shown below) the author needs to use, not the simple
	211	* JMPENV_PUSH, but several of its constitutent macros, to arrange for
	212	* the Perl internals to call thrower() rather than longjmp() to
	213	* report exceptions:
	214	*
	215	* dJMPENV;
	216	* JMPENV_PUSH_INIT(thrower);
	217	* try {
	218	* ... stuff that may throw exceptions ...
	219	* }
	220	* catch (int why) { // or whatever matches thrower()
	221	* JMPENV_POST_CATCH;
	222	* EXCEPT_SET(why);
	223	* switch (why) {
	224	* ... // handle various Perl exception codes
	225	* }
	226	* }
	227	* JMPENV_POP; // don't forget this!
	228	*/
	229
db36c5a1	230	#define dJMPENV JMPENV cur_env; \
db36c5a1	231	volatile JMPENV *pcur_env = ((cur_env.je_noset = 0),&cur_env)
312caa8e	232
db36c5a1	233	#define JMPENV_PUSH_INIT_ENV(ce,THROWFUNC) \
6224f72b	234	STMT_START { \
db36c5a1	235	(ce).je_throw = (THROWFUNC); \
	236	(ce).je_ret = -1; \
	237	(ce).je_mustcatch = FALSE; \
	238	(ce).je_prev = PL_top_env; \
	239	PL_top_env = &(ce); \
6224f72b	240	OP_REG_TO_MEM; \
312caa8e	241	} STMT_END
1d651c14	242
db36c5a1	243	#define JMPENV_PUSH_INIT(THROWFUNC) JMPENV_PUSH_INIT_ENV((JMPENV)pcur_env,THROWFUNC)
1d651c14	244
db36c5a1	245	#define JMPENV_POST_CATCH_ENV(ce) \
312caa8e	246	STMT_START { \
6224f72b	247	OP_MEM_TO_REG; \
db36c5a1	248	PL_top_env = &(ce); \
6224f72b	249	} STMT_END
312caa8e	250
db36c5a1	251	#define JMPENV_POST_CATCH JMPENV_POST_CATCH_ENV((JMPENV)pcur_env)
1d651c14	252
1d651c14	253
db36c5a1	254	#define JMPENV_PUSH_ENV(ce,v) \
	255	STMT_START { \
	256	if (!(ce).je_noset) { \
	257	JMPENV_PUSH_INIT_ENV(ce,NULL); \
	258	EXCEPT_SET_ENV(ce,PerlProc_setjmp((ce).je_buf, 1));\
	259	(ce).je_noset = 1; \
	260	} \
	261	else \
	262	EXCEPT_SET_ENV(ce,0); \
	263	JMPENV_POST_CATCH_ENV(ce); \
	264	(v) = EXCEPT_GET_ENV(ce); \
312caa8e	265	} STMT_END
312caa8e	266
db36c5a1	267	#define JMPENV_PUSH(v) JMPENV_PUSH_ENV((JMPENV)pcur_env,v)
1d651c14	268
db36c5a1	269	#define JMPENV_POP_ENV(ce) \
db36c5a1	270	STMT_START { PL_top_env = (ce).je_prev; } STMT_END
312caa8e	271
db36c5a1	272	#define JMPENV_POP JMPENV_POP_ENV((JMPENV)pcur_env)
1d651c14	273
22921e25	274	#define JMPENV_JUMP(v) \
22921e25	275	STMT_START { \
462e5cf6	276	OP_REG_TO_MEM; \
312caa8e	277	if (PL_top_env->je_prev) { \
	278	if (PL_top_env->je_throw) \
	279	PL_top_env->je_throw(v); \
	280	else \
	281	PerlProc_longjmp(PL_top_env->je_buf, (v)); \
	282	} \
6224f72b	283	if ((v) == 2) \
312caa8e	284	PerlProc_exit(STATUS_NATIVE_EXPORT); \
bf49b057	285	PerlIO_printf(Perl_error_log, "panic: top_env\n"); \
312caa8e	286	PerlProc_exit(1); \
22921e25	287	} STMT_END
312caa8e	288
db36c5a1	289	#define EXCEPT_GET_ENV(ce) ((ce).je_ret)
	290	#define EXCEPT_GET EXCEPT_GET_ENV((JMPENV)pcur_env)
	291	#define EXCEPT_SET_ENV(ce,v) ((ce).je_ret = (v))
	292	#define EXCEPT_SET(v) EXCEPT_SET_ENV((JMPENV)pcur_env,v)
312caa8e	293
db36c5a1	294	#define CATCH_GET (PL_top_env->je_mustcatch)
db36c5a1	295	#define CATCH_SET(v) (PL_top_env->je_mustcatch = (v))