582 lines
		
	
	
	
		
			14 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			582 lines
		
	
	
	
		
			14 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* $Header$ */
 | |
| /*	C O D E - G E N E R A T I N G   R O U T I N E S		*/
 | |
| 
 | |
| #include	<em.h>
 | |
| #include	"botch_free.h"
 | |
| #include	<alloc.h>
 | |
| #include	"nofloat.h"
 | |
| #include	"dataflow.h"
 | |
| #include	"use_tmp.h"
 | |
| #include	"arith.h"
 | |
| #include	"type.h"
 | |
| #include	"idf.h"
 | |
| #include	"label.h"
 | |
| #include	"code.h"
 | |
| #include	"stmt.h"
 | |
| #include	"def.h"
 | |
| #include	"expr.h"
 | |
| #include	"sizes.h"
 | |
| #include	"stack.h"
 | |
| #include	"level.h"
 | |
| #include	"decspecs.h"
 | |
| #include	"declar.h"
 | |
| #include	"Lpars.h"
 | |
| #include	"mes.h"
 | |
| #include	"LLlex.h"
 | |
| #include	"specials.h"
 | |
| #include	"atw.h"
 | |
| #include	"assert.h"
 | |
| 
 | |
| label lab_count = 1;
 | |
| label datlab_count = 1;
 | |
| 
 | |
| #ifndef NOFLOAT
 | |
| int fp_used;
 | |
| #endif NOFLOAT
 | |
| 
 | |
| extern char options[];
 | |
| char *symbol2str();
 | |
| 
 | |
| init_code(dst_file)
 | |
| 	char *dst_file;
 | |
| {
 | |
| 	/*	init_code() initialises the output file on which the
 | |
| 		compact EM code is written
 | |
| 	*/
 | |
| 	C_init(word_size, pointer_size); /* initialise EM module */
 | |
| 	if (C_open(dst_file) == 0)
 | |
| 		fatal("cannot write to %s\n", dst_file);
 | |
| #ifdef USE_TMP
 | |
| 	if (options['N'])
 | |
| #endif	USE_TMP
 | |
| 	famous_first_words();
 | |
| }
 | |
| 
 | |
| famous_first_words()
 | |
| {
 | |
| 	C_magic();
 | |
| 	C_ms_emx(word_size, pointer_size);
 | |
| }
 | |
| 
 | |
| static struct string_cst *str_list = 0;
 | |
| 
 | |
| code_string(val, len, dlb)
 | |
| 	char *val;
 | |
| 	int len;
 | |
| 	label dlb;
 | |
| {
 | |
| 	register struct string_cst *sc = new_string_cst();
 | |
| 
 | |
| 	C_ina_dlb(dlb);
 | |
| 	sc->next = str_list;
 | |
| 	str_list = sc;
 | |
| 	sc->sc_value = val;
 | |
| 	sc->sc_len = len;
 | |
| 	sc->sc_dlb = dlb;
 | |
| }
 | |
| 
 | |
| def_strings(sc)
 | |
| 	register struct string_cst *sc;
 | |
| {
 | |
| 	if (sc) {
 | |
| 		def_strings(sc->next);
 | |
| 		C_df_dlb(sc->sc_dlb);
 | |
| 		str_cst(sc->sc_value, sc->sc_len);
 | |
| 		free_string_cst(sc);
 | |
| 	}
 | |
| }
 | |
| 
 | |
| end_code()
 | |
| {
 | |
| 	/*	end_code() performs the actions to be taken when closing
 | |
| 		the output stream.
 | |
| 	*/
 | |
| 	def_strings(str_list);
 | |
| 	str_list = 0;
 | |
| 	C_ms_src((int)(LineNumber - 2), FileName);
 | |
| 	C_close();
 | |
| }
 | |
| 
 | |
| #ifdef	USE_TMP
 | |
| prepend_scopes(dst_file)
 | |
| 	char *dst_file;
 | |
| {
 | |
| 	/*	prepend_scopes() runs down the list of global idf's
 | |
| 		and generates those exa's, exp's, ina's and inp's
 | |
| 		that superior hindsight has provided, on the file dst_file.
 | |
| 	*/
 | |
| 	register struct stack_entry *se = local_level->sl_entry;
 | |
| 
 | |
| 	if (C_open(dst_file) == 0)
 | |
| 		fatal("cannot create %s", dst_file ? dst_file : "stdout");
 | |
| 	famous_first_words();
 | |
| 	while (se != 0)	{
 | |
| 		register struct idf *id = se->se_idf;
 | |
| 		register struct def *df = id->id_def;
 | |
| 		
 | |
| 		if (df && (df->df_initialized || df->df_used || df->df_alloc))
 | |
| 			code_scope(id->id_text, df);
 | |
| 		se = se->next;
 | |
| 	}
 | |
| 	C_close();
 | |
| }
 | |
| #endif	USE_TMP
 | |
| 
 | |
| code_scope(text, def)
 | |
| 	char *text;
 | |
| 	register struct def *def;
 | |
| {
 | |
| 	/*	generates code for one name, text, of the storage class
 | |
| 		as given by def, if meaningful.
 | |
| 	*/
 | |
| 	int fund = def->df_type->tp_fund;
 | |
| 	
 | |
| 	switch (def->df_sc)	{
 | |
| 	case EXTERN:
 | |
| 	case GLOBAL:
 | |
| 	case IMPLICIT:
 | |
| 		if (fund == FUNCTION)
 | |
| 			C_exp(text);
 | |
| 		else
 | |
| 			C_exa_dnam(text);
 | |
| 		break;
 | |
| 	case STATIC:
 | |
| 		if (fund == FUNCTION)
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| 			C_inp(text);
 | |
| 		else
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| 			C_ina_dnam(text);
 | |
| 		break;
 | |
| 	}
 | |
| }
 | |
| 
 | |
| static label return_label;
 | |
| static char return_expr_occurred;
 | |
| static struct type *func_tp;
 | |
| static label func_res_label;
 | |
| static char *last_fn_given = "";
 | |
| static label file_name_label;
 | |
| 
 | |
| begin_proc(name, def)	/* to be called when entering a procedure	*/
 | |
| 	char *name;
 | |
| 	register struct def *def;
 | |
| {
 | |
| 	/*	begin_proc() is called at the entrance of a new function
 | |
| 		and performs the necessary code generation:
 | |
| 		-	a scope indicator (if needed) exp/inp
 | |
| 		-	the procedure entry pro $name
 | |
| 		-	reserves some space if the result of the function
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| 			does not fit in the return area
 | |
| 		-	a fil pseudo instruction
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| 	*/
 | |
| 	arith size;
 | |
| 	register struct type *tp = def->df_type;
 | |
| 
 | |
| #ifdef USE_TMP
 | |
| 	if (options['N']) code_scope(name,def);
 | |
| #else USE_TMP
 | |
| 	code_scope(name, def);
 | |
| #endif	USE_TMP
 | |
| #ifdef	DATAFLOW
 | |
| 	if (options['d'])
 | |
| 		DfaStartFunction(name);
 | |
| #endif	DATAFLOW
 | |
| 
 | |
| 	if (tp->tp_fund != FUNCTION) {
 | |
| 		error("making function body for non-function");
 | |
| 		tp = error_type;
 | |
| 	}
 | |
| 	else
 | |
| 		tp = tp->tp_up;
 | |
| 	func_tp = tp;
 | |
| 	size = ATW(tp->tp_size);
 | |
| 	C_pro_narg(name);
 | |
| 	if (is_struct_or_union(tp->tp_fund))	{
 | |
| 		C_df_dlb(func_res_label = data_label());
 | |
| 		C_bss_cst(size, (arith)0, 1);
 | |
| 	}
 | |
| 	else
 | |
| 		func_res_label = 0;
 | |
| 	/*	Special arrangements if the function result doesn't fit in
 | |
| 		the function return area of the EM machine.  The size of
 | |
| 		the function return area is implementation dependent.
 | |
| 	*/
 | |
| 	lab_count = (label) 1;
 | |
| 	return_label = text_label();
 | |
| 	return_expr_occurred = 0;
 | |
| 	prc_entry(name);
 | |
| 	if (! options['L'])	{	/* profiling */
 | |
| 		if (strcmp(last_fn_given, FileName) != 0)	{
 | |
| 			/* previous function came from other file */
 | |
| 			C_df_dlb(file_name_label = data_label());
 | |
| 			C_con_scon(last_fn_given = FileName,
 | |
| 				(arith)(strlen(FileName) + 1));
 | |
| 		}
 | |
| 		/* enable debug trace of EM source */
 | |
| 		C_fil_dlb(file_name_label, (arith)0);
 | |
| 		C_lin((arith)LineNumber);
 | |
| 	}
 | |
| }
 | |
| 
 | |
| end_proc(fbytes, nbytes)
 | |
| 	arith fbytes, nbytes;
 | |
| {
 | |
| 	/*	end_proc() deals with the code to be generated at the end of
 | |
| 		a function, as there is:
 | |
| 		-	the EM ret instruction: "ret 0"
 | |
| 		-	loading of the function result in the function
 | |
| 			result area if there has been a return <expr>
 | |
| 			in the function body (see do_return_expr())
 | |
| 		-	indication of the use of floating points
 | |
| 		-	indication of the number of bytes used for
 | |
| 			formal parameters
 | |
| 		-	use of special identifiers such as "setjmp"
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| 		-	"end" + number of bytes used for local variables
 | |
| 	*/
 | |
| 	static int mes_flt_given = 0;	/* once for the whole program */
 | |
| 
 | |
| #ifdef	DATAFLOW
 | |
| 	if (options['d'])
 | |
| 		DfaEndFunction();
 | |
| #endif	DATAFLOW
 | |
| 	prc_exit();
 | |
| 	C_ret((arith)0);
 | |
| 	if (return_expr_occurred != 0)	{
 | |
| 		C_df_ilb(return_label);
 | |
| 		prc_exit();
 | |
| 		if (func_res_label != 0)	{
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| 			C_lae_dlb(func_res_label, (arith)0);
 | |
| 			store_block(func_tp->tp_size, func_tp->tp_align);
 | |
| 			C_lae_dlb(func_res_label, (arith)0);
 | |
| 			C_ret(pointer_size);
 | |
| 		}
 | |
| 		else
 | |
| 			C_ret(ATW(func_tp->tp_size));
 | |
| 	}
 | |
| #ifndef NOFLOAT
 | |
| 	if (fp_used && mes_flt_given == 0)	{
 | |
| 		/* floating point used	*/
 | |
| 		C_ms_flt();
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| 		mes_flt_given++;
 | |
| 	}
 | |
| #endif NOFLOAT
 | |
| 	C_ms_par(fbytes);		/* # bytes for formals		*/
 | |
| 	if (sp_occurred[SP_SETJMP]) {	/* indicate use of "setjmp"	*/
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| 		C_ms_gto();
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| 		sp_occurred[SP_SETJMP] = 0;
 | |
| 	}
 | |
| 	C_end(ATW(nbytes));
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| }
 | |
| 
 | |
| do_return()
 | |
| {
 | |
| 	/*	do_return generates a direct return */
 | |
| 	/*	isn't a jump to the return label smarter ??? */
 | |
| 	prc_exit();
 | |
| 	C_ret((arith)0);
 | |
| }
 | |
| 
 | |
| do_return_expr(expr)
 | |
| 	struct expr *expr;
 | |
| {
 | |
| 	/*	do_return_expr() generates the expression and the jump for
 | |
| 		a return statement with an expression.
 | |
| 	*/
 | |
| 	ch7cast(&expr, RETURN, func_tp);
 | |
| 	code_expr(expr, RVAL, TRUE, NO_LABEL, NO_LABEL);
 | |
| 	C_bra(return_label);
 | |
| 	return_expr_occurred = 1;
 | |
| }
 | |
| 
 | |
| code_declaration(idf, expr, lvl, sc)
 | |
| 	register struct idf *idf;	/* idf to be declared	*/
 | |
| 	struct expr *expr;	/* initialisation; NULL if absent	*/
 | |
| 	int lvl;		/* declaration level	*/
 | |
| 	int sc;			/* storage class, as in the declaration */
 | |
| {
 | |
| 	/*	code_declaration() does the actual declaration of the
 | |
| 		variable indicated by "idf" on declaration level "lvl".
 | |
| 		If the variable is initialised, the expression is given
 | |
| 		in "expr".
 | |
| 		There are some cases to be considered:
 | |
| 		-	filter out typedefs, they don't correspond to code;
 | |
| 		-	global variables, coded only if initialized;
 | |
| 		-	local static variables;
 | |
| 		-	local automatic variables;
 | |
| 		Since the expression may be modified in the process,
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| 		code_declaration() frees it after use, as the caller can
 | |
| 		no longer do so.
 | |
| 		
 | |
| 		If there is a storage class indication (EXTERN/STATIC),
 | |
| 		code_declaration() will generate an exa or ina.
 | |
| 		The sc is the actual storage class, as given in the
 | |
| 		declaration.  This is to allow:
 | |
| 			extern int a;
 | |
| 			int a = 5;
 | |
| 		while at the same time forbidding
 | |
| 			extern int a = 5;
 | |
| 	*/
 | |
| 	char *text = idf->id_text;
 | |
| 	register struct def *def = idf->id_def;
 | |
| 	register arith size = def->df_type->tp_size;
 | |
| 	int def_sc = def->df_sc;
 | |
| 	
 | |
| 	if (def_sc == TYPEDEF)	/* no code for typedefs		*/
 | |
| 		return;
 | |
| 	if (sc == EXTERN && expr && !is_anon_idf(idf))
 | |
| 		error("%s is extern; cannot initialize", text);
 | |
| 	if (lvl == L_GLOBAL)	{	/* global variable	*/
 | |
| 		/* is this an allocating declaration? */
 | |
| 		if (	(sc == 0 || sc == STATIC)
 | |
| 			&& def->df_type->tp_fund != FUNCTION
 | |
| 			&& size >= 0
 | |
| 		)
 | |
| 			def->df_alloc = ALLOC_SEEN;
 | |
| 		if (expr) {	/* code only if initialized */
 | |
| #ifdef USE_TMP
 | |
| 			if (options['N'])
 | |
| #endif USE_TMP
 | |
| 			code_scope(text, def);
 | |
| 			def->df_alloc = ALLOC_DONE;
 | |
| 			C_df_dnam(text);
 | |
| 			do_ival(&(def->df_type), expr);
 | |
| 			free_expression(expr);
 | |
| 		}
 | |
| 	}
 | |
| 	else
 | |
| 	if (lvl >= L_LOCAL)	{	/* local variable	*/
 | |
| 		/* STATIC, EXTERN, GLOBAL, IMPLICIT, AUTO or REGISTER */
 | |
| 		switch (def_sc)	{
 | |
| 		case STATIC:
 | |
| 			if (def->df_type->tp_fund == FUNCTION) {
 | |
| 				/* should produce "inp $function" ??? */
 | |
| 				break;
 | |
| 			}
 | |
| 			/*	they are handled on the spot and get an
 | |
| 				integer label in EM.
 | |
| 			*/
 | |
| 			C_df_dlb((label)def->df_address);
 | |
| 			if (expr) { /* there is an initialisation */
 | |
| 				do_ival(&(def->df_type), expr);
 | |
| 				free_expression(expr);
 | |
| 			}
 | |
| 			else {	/* produce blank space */
 | |
| 				if (size <= 0) {
 | |
| 					error("size of %s unknown", text);
 | |
| 					size = (arith)0;
 | |
| 				}
 | |
| 				C_bss_cst(align(size, word_align), (arith)0, 1);
 | |
| 			}
 | |
| 			break;
 | |
| 		case EXTERN:
 | |
| 		case GLOBAL:
 | |
| 		case IMPLICIT:
 | |
| 			/* we are sure there is no expression */
 | |
| #ifdef	USE_TMP
 | |
| 			if (options['N'])
 | |
| #endif	USE_TMP
 | |
| 			code_scope(text, def);
 | |
| 			break;
 | |
| 		case AUTO:
 | |
| 		case REGISTER:
 | |
| 			if (expr)
 | |
| 				loc_init(expr, idf);
 | |
| 			break;
 | |
| 		default:
 | |
| 			crash("bad local storage class");
 | |
| 			break;
 | |
| 		}
 | |
| 	}
 | |
| }
 | |
| 
 | |
| loc_init(expr, id)
 | |
| 	struct expr *expr;
 | |
| 	register struct idf *id;
 | |
| {
 | |
| 	/*	loc_init() generates code for the assignment of
 | |
| 		expression expr to the local variable described by id.
 | |
| 		It frees the expression afterwards.
 | |
| 	*/
 | |
| 	register struct type *tp = id->id_def->df_type;
 | |
| 	register struct expr *e = expr;
 | |
| 	
 | |
| 	ASSERT(id->id_def->df_sc != STATIC);
 | |
| 	switch (tp->tp_fund)	{
 | |
| 	case ARRAY:
 | |
| 	case STRUCT:
 | |
| 	case UNION:
 | |
| 		error("no automatic aggregate initialisation");
 | |
| 		free_expression(e);
 | |
| 		return;
 | |
| 	}
 | |
| 	if (ISCOMMA(e))	{	/* embraced: int i = {12};	*/
 | |
| 		if (options['R'])	{
 | |
| 			if (ISCOMMA(e->OP_LEFT)) /* int i = {{1}} */
 | |
| 				expr_error(e, "extra braces not allowed");
 | |
| 			else
 | |
| 			if (e->OP_RIGHT != 0) /* int i = {1 , 2} */
 | |
| 				expr_error(e, "too many initializers");
 | |
| 		}
 | |
| 		while (e)	{
 | |
| 			loc_init(e->OP_LEFT, id);
 | |
| 			e = e->OP_RIGHT;
 | |
| 		}
 | |
| 	}
 | |
| 	else	{	/* not embraced	*/
 | |
| 		struct value vl;
 | |
| 
 | |
| 		ch7cast(&expr, '=', tp);	/* may modify expr */
 | |
| 		EVAL(expr, RVAL, TRUE, NO_LABEL, NO_LABEL);
 | |
| 		free_expression(expr);
 | |
| 		vl.vl_class = Name;
 | |
| 		vl.vl_data.vl_idf = id;
 | |
| 		vl.vl_value = (arith)0;
 | |
| 		store_val(&vl, tp);
 | |
| 	}
 | |
| }
 | |
| 
 | |
| bss(idf)
 | |
| 	register struct idf *idf;
 | |
| {
 | |
| 	/*	bss() allocates bss space for the global idf.
 | |
| 	*/
 | |
| 	arith size = idf->id_def->df_type->tp_size;
 | |
| 	
 | |
| #ifdef	USE_TMP
 | |
| 	if (options['N'])
 | |
| #endif	USE_TMP
 | |
| 	code_scope(idf->id_text, idf->id_def);
 | |
| 	/*	Since bss() is only called if df_alloc is non-zero, and
 | |
| 		since df_alloc is only non-zero if size >= 0, we have:
 | |
| 	*/
 | |
| 	/*	but we already gave a warning at the declaration of the
 | |
| 		array. Besides, the message given here does not apply to
 | |
| 		voids
 | |
| 	
 | |
| 	if (options['R'] && size == 0)
 | |
| 		warning("actual array of size 0");
 | |
| 	*/
 | |
| 	C_df_dnam(idf->id_text);
 | |
| 	C_bss_cst(align(size, word_align), (arith)0, 1);
 | |
| }
 | |
| 
 | |
| formal_cvt(df)
 | |
| 	register struct def *df;
 | |
| {
 | |
| 	/*	formal_cvt() converts a formal parameter of type char or
 | |
| 		short from int to that type.
 | |
| 	*/
 | |
| 	register struct type *tp = df->df_type;
 | |
| 
 | |
| 	if (tp->tp_size != int_size &&
 | |
| 		(tp->tp_fund == CHAR || tp->tp_fund == SHORT)
 | |
| 	) {
 | |
| 		C_lol(df->df_address);
 | |
| 		/* conversion(int_type, df->df_type); ???
 | |
| 		   No, you can't do this on the stack! (CJ)
 | |
| 		*/
 | |
| 		C_lal(df->df_address);
 | |
| 		C_sti(tp->tp_size);
 | |
| 		df->df_register = REG_NONE;
 | |
| 	}
 | |
| }
 | |
| 
 | |
| code_expr(expr, val, code, tlbl, flbl)
 | |
| 	struct expr *expr;
 | |
| 	label tlbl, flbl;
 | |
| {
 | |
| 	/*	code_expr() is the parser's interface to the expression code
 | |
| 		generator.  If line number trace is wanted, it generates a
 | |
| 		lin instruction.  EVAL() is called directly.
 | |
| 	*/
 | |
| 	if (! options['L'])	/* profiling	*/
 | |
| 		C_lin((arith)LineNumber);
 | |
| 	EVAL(expr, val, code, tlbl, flbl);
 | |
| }
 | |
| 
 | |
| /*	The FOR/WHILE/DO/SWITCH stacking mechanism:
 | |
| 	stack_stmt() has to be called at the entrance of a
 | |
| 	for, while, do or switch statement to indicate the
 | |
| 	EM labels where a subsequent break or continue causes
 | |
| 	the program to jump to.
 | |
| */
 | |
| static struct stmt_block *stmt_stack;	/* top of statement stack */
 | |
| 
 | |
| /*	code_break() generates EM code needed at the occurrence of "break":
 | |
| 	it generates a branch instruction to the break label of the
 | |
| 	innermost statement in which break has a meaning.
 | |
| 	As "break" is legal in any of 'while', 'do', 'for' or 'switch',
 | |
| 	which are the only ones that are stacked, only the top of
 | |
| 	the stack is interesting.
 | |
| */
 | |
| code_break()
 | |
| {
 | |
| 	register struct stmt_block *stmt_block = stmt_stack;
 | |
| 
 | |
| 	if (stmt_block)
 | |
| 		C_bra(stmt_block->st_break);
 | |
| 	else
 | |
| 		error("break not inside for, while, do or switch");
 | |
| }
 | |
| 
 | |
| /*	code_continue() generates EM code needed at the occurrence of
 | |
| 	"continue":
 | |
| 	it generates a branch instruction to the continue label of the
 | |
| 	innermost statement in which continue has a meaning.
 | |
| */
 | |
| code_continue()
 | |
| {
 | |
| 	register struct stmt_block *stmt_block = stmt_stack;
 | |
| 
 | |
| 	while (stmt_block)	{
 | |
| 		if (stmt_block->st_continue)	{
 | |
| 			C_bra(stmt_block->st_continue);
 | |
| 			return;
 | |
| 		}
 | |
| 		stmt_block = stmt_block->next;
 | |
| 	}
 | |
| 	error("continue not inside for, while or do");
 | |
| }
 | |
| 
 | |
| stack_stmt(break_label, cont_label)
 | |
| 	label break_label, cont_label;
 | |
| {
 | |
| 	register struct stmt_block *stmt_block = new_stmt_block();
 | |
| 
 | |
| 	stmt_block->next = stmt_stack;
 | |
| 	stmt_block->st_break = break_label;
 | |
| 	stmt_block->st_continue = cont_label;
 | |
| 	stmt_stack = stmt_block;
 | |
| }
 | |
| 
 | |
| unstack_stmt()
 | |
| {
 | |
| 	/*	unstack_stmt() unstacks the data of a statement
 | |
| 		which may contain break or continue
 | |
| 	*/
 | |
| 	register struct stmt_block *sbp = stmt_stack;
 | |
| 	stmt_stack = sbp->next;
 | |
| 	free_stmt_block(sbp);
 | |
| }
 | |
| 
 | |
| static label l1;
 | |
| 
 | |
| prc_entry(name)
 | |
| 	char *name;
 | |
| {
 | |
| 	if (options['p']) {
 | |
| 		C_df_dlb(l1 = data_label());
 | |
| 		C_rom_scon(name, (arith) (strlen(name) + 1));
 | |
| 		C_lae_dlb(l1);
 | |
| 		C_cal("procentry");
 | |
| 		C_asp(pointer_size);
 | |
| 	}
 | |
| }
 | |
| 
 | |
| prc_exit()
 | |
| {
 | |
| 	if (options['p']) {
 | |
| 		C_lae_dlb(l1);
 | |
| 		C_cal("procexit");
 | |
| 		C_asp(pointer_size);
 | |
| 	}
 | |
| }
 |