546 lines
		
	
	
	
		
			11 KiB
		
	
	
	
		
			Text
		
	
	
	
	
	
			
		
		
	
	
			546 lines
		
	
	
	
		
			11 KiB
		
	
	
	
		
			Text
		
	
	
	
	
	
| /* D E C L A R A T I O N S */
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| 
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| {
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| #include	"debug.h"
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| 
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| #include	<em_arith.h>
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| #include	<em_label.h>
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| #include	<alloc.h>
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| #include	<assert.h>
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| 
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| #include	"idf.h"
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| #include	"LLlex.h"
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| #include	"def.h"
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| #include	"type.h"
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| #include	"scope.h"
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| #include	"node.h"
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| #include	"misc.h"
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| #include	"main.h"
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| #include	"chk_expr.h"
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| #include	"warning.h"
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| 
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| int		proclevel = 0;		/* nesting level of procedures */
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| int		return_occurred;	/* set if a return occurs in a block */
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| }
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| 
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| ProcedureDeclaration
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| {
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| 	struct def *df;
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| } :
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| 			{ ++proclevel; }
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| 	ProcedureHeading(&df, D_PROCEDURE)
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| 	';' block(&(df->prc_body))
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| 	IDENT
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| 			{ EndProc(df, dot.TOK_IDF);
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| 			  --proclevel;
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| 			}
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| ;
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| 
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| ProcedureHeading(struct def **pdf; int type;)
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| {
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| 	struct type *tp = 0;
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| #define needs_static_link()	(proclevel > 1)
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| 	arith parmaddr = needs_static_link() ? pointer_size : 0;
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| 	struct paramlist *pr = 0;
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| } :
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| 	PROCEDURE IDENT
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| 			{ *pdf = DeclProc(type, dot.TOK_IDF); }
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| 	FormalParameters(&pr, &parmaddr, &tp)?
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| 			{ CheckWithDef(*pdf, proc_type(tp, pr, parmaddr));
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| 			  if (tp && IsConstructed(tp)) {
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| warning(W_STRICT, "procedure \"%s\" has a constructed result type",
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| 	(*pdf)->df_idf->id_text);
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| 			  }
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| 			}
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| ;
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| 
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| block(struct node **pnd;) :
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| 	[	%persistent
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| 		declaration
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| 	]*
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| 			{ return_occurred = 0; *pnd = 0; }
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| 	[	%persistent
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| 		BEGIN
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| 		StatementSequence(pnd)
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| 	]?
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| 	END
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| ;
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| 
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| declaration:
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| 	CONST [ %persistent ConstantDeclaration ';' ]*
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| |
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| 	TYPE [ %persistent TypeDeclaration ';' ]*
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| |
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| 	VAR [ %persistent VariableDeclaration ';' ]*
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| |
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| 	ProcedureDeclaration ';'
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| |
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| 	ModuleDeclaration ';'
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| ;
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| 
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| FormalParameters(struct paramlist **ppr; arith *parmaddr; struct type **ptp;):
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| 	'('
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| 	[
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| 		FPSection(ppr, parmaddr)
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| 		[
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| 			';' FPSection(ppr, parmaddr)
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| 		]*
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| 	]?
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| 	')'
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| 	[	':' qualtype(ptp)
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| 	]?
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| ;
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| 
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| FPSection(struct paramlist **ppr; arith *parmaddr;)
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| {
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| 	struct node *FPList;
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| 	struct type *tp;
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| 	int VARp;
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| } :
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| 	var(&VARp) IdentList(&FPList) ':' FormalType(&tp)
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| 			{ EnterParamList(ppr, FPList, tp, VARp, parmaddr); }
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| ;
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| 
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| FormalType(struct type **ptp;)
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| {
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| 	extern arith ArrayElSize();
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| } :
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| 	ARRAY OF qualtype(ptp)
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| 		{ register struct type *tp = construct_type(T_ARRAY, NULLTYPE);
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| 
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| 		  tp->arr_elem = *ptp;
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| 		  *ptp = tp;
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| 		  tp->arr_elsize = ArrayElSize(tp->arr_elem);
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| 		  tp->tp_align = tp->arr_elem->tp_align;
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| 		}
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| |
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| 	 qualtype(ptp)
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| ;
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| 
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| TypeDeclaration
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| {
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| 	struct def *df;
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| 	struct type *tp;
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| 	struct node *nd;
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| }:
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| 	IDENT		{ df = define(dot.TOK_IDF, CurrentScope, D_TYPE);
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| 			  nd = MkLeaf(Name, &dot);
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| 			}
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| 	'=' type(&tp)
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| 			{ DeclareType(nd, df, tp);
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| 			  free_node(nd);
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| 			}
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| ;
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| 
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| type(struct type **ptp;):
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| 	%default SimpleType(ptp)
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| |
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| 	ArrayType(ptp)
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| |
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| 	RecordType(ptp)
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| |
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| 	SetType(ptp)
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| |
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| 	PointerType(ptp)
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| |
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| 	ProcedureType(ptp)
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| ;
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| 
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| SimpleType(struct type **ptp;)
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| {
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| 	struct type *tp;
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| } :
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| 	qualtype(ptp)
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| 	[
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| 		/* nothing */
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| 	|
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| 		SubrangeType(&tp)
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| 		/* The subrange type is given a base type by the
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| 		   qualident (this is new modula-2).
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| 		*/
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| 			{ chk_basesubrange(tp, *ptp); }
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| 	]
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| |
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| 	enumeration(ptp)
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| |
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| 	SubrangeType(ptp)
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| ;
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| 
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| enumeration(struct type **ptp;)
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| {
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| 	struct node *EnumList;
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| } :
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| 	'(' IdentList(&EnumList) ')'
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| 		{ register struct type *tp =
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| 		  	standard_type(T_ENUMERATION, int_align, int_size);
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| 
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| 		  *ptp = tp;
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| 		  EnterEnumList(EnumList, tp);
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| 		  if (ufit(tp->enm_ncst-1, 1)) {
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| 			tp->tp_size = 1;
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| 			tp->tp_align = 1;
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| 		  }
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| 		  else if (ufit(tp->enm_ncst-1, short_size)) {
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| 			tp->tp_size = short_size;
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| 			tp->tp_align = short_align;
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| 		  }
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| 		}
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| ;
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| 
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| IdentList(struct node **p;)
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| {
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| 	register struct node *q;
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| } :
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| 	IDENT		{ *p = q = MkLeaf(Value, &dot); }
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| 	[ %persistent
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| 		',' IDENT
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| 			{ q->next = MkLeaf(Value, &dot);
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| 			  q = q->next;
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| 			}
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| 	]*
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| 			{ q->next = 0; }
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| ;
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| 
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| SubrangeType(struct type **ptp;)
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| {
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| 	struct node *nd1, *nd2;
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| }:
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| 	/*
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| 	   This is not exactly the rule in the new report, but see
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| 	   the rule for "SimpleType".
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| 	*/
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| 	'[' ConstExpression(&nd1)
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| 	UPTO ConstExpression(&nd2)
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| 	']'
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| 			{ *ptp = subr_type(nd1, nd2);
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| 			  free_node(nd1);
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| 			  free_node(nd2);
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| 			}
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| ;
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| 
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| ArrayType(struct type **ptp;)
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| {
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| 	struct type *tp;
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| 	register struct type *tp2;
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| } :
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| 	ARRAY SimpleType(&tp)
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| 			{ *ptp = tp2 = construct_type(T_ARRAY, tp); }
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| 	[
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| 		',' SimpleType(&tp)
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| 			{ tp2->arr_elem = construct_type(T_ARRAY, tp);
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| 			  tp2 = tp2->arr_elem;
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| 			}
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| 	]* OF type(&tp)
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| 			{ tp2->arr_elem = tp;
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| 			  ArraySizes(*ptp);
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| 			}
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| ;
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| 
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| RecordType(struct type **ptp;)
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| {
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| 	register struct scope *scope;
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| 	arith size = 0;
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| 	int xalign = struct_align;
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| }
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| :
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| 	RECORD
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| 		{ open_scope(OPENSCOPE);	/* scope for fields of record */
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| 		  scope = CurrentScope;
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| 		  close_scope(0);
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| 		}
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| 	FieldListSequence(scope, &size, &xalign)
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| 		{ if (size == 0) {
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| 			warning(W_ORDINARY, "empty record declaration");
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| 			size = 1;
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| 		  }
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| 		  *ptp = standard_type(T_RECORD, xalign, size);
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| 		  (*ptp)->rec_scope = scope;
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| 		}
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| 	END
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| ;
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| 
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| FieldListSequence(struct scope *scope; arith *cnt; int *palign;):
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| 	FieldList(scope, cnt, palign)
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| 	[
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| 		';' FieldList(scope, cnt, palign)
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| 	]*
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| ;
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| 
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| FieldList(struct scope *scope; arith *cnt; int *palign;)
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| {
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| 	struct node *FldList;
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| 	register struct idf *id = 0;
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| 	struct type *tp;
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| 	struct node *nd1;
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| 	register struct node *nd;
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| 	arith tcnt, max;
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| } :
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| [
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| 	IdentList(&FldList) ':' type(&tp)
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| 			{ *palign = lcm(*palign, tp->tp_align);
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| 			  EnterFieldList(FldList, tp, scope, cnt);
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| 			}
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| |
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| 	CASE
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| 	/* Also accept old fashioned Modula-2 syntax, but give a warning.
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| 	   Sorry for the complicated code.
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| 	*/
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| 	[ qualident(&nd1)
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| 			{ nd = nd1; }
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| 	  [ ':' qualtype(&tp)
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| 			/* This is correct, in both kinds of Modula-2, if
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| 		   	   the first qualident is a single identifier.
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| 			*/
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| 			{ if (nd->nd_class != Name) {
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| 				error("illegal variant tag");
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| 		  	  }
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| 		  	  else	id = nd->nd_IDF;
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| 			  FreeNode(nd);
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| 			}
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| 	  |		/* Old fashioned! the first qualident now represents
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| 			   the type
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| 			*/
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| 			{ warning(W_OLDFASHIONED, "old fashioned Modula-2 syntax; ':' missing");
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| 			  if (ChkDesignator(nd) &&
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| 			      (nd->nd_class != Def ||
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| 			       !(nd->nd_def->df_kind&(D_ERROR|D_ISTYPE)) ||
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| 			       !nd->nd_def->df_type)) {
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| 				node_error(nd, "type expected");
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| 				tp = error_type;
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| 			  }
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| 			  else tp = nd->nd_def->df_type;
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| 			  FreeNode(nd);
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| 			}
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| 	  ]
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| 	| ':' qualtype(&tp)
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| 	  /* Aha, third edition. Well done! */
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| 	]
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| 			{ if (id) {
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| 			  	register struct def *df = define(id,
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| 								 scope,
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| 								 D_FIELD);
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| 			  	if (!(tp->tp_fund & T_DISCRETE)) {
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| 					error("illegal type in variant");
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| 			  	}
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| 			  	df->df_type = tp;
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| 			  	df->fld_off = align(*cnt, tp->tp_align);
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| 			  	*cnt = df->fld_off + tp->tp_size;
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| 			  	df->df_flags |= D_QEXPORTED;
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| 			  }
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| 			  tcnt = *cnt;
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| 			}
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| 	OF variant(scope, &tcnt, tp, palign)
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| 			{ max = tcnt; tcnt = *cnt; }
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| 	[
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| 	  '|' variant(scope, &tcnt, tp, palign)
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| 			{ if (tcnt > max) max = tcnt; tcnt = *cnt; }
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| 	]*
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| 	[ ELSE FieldListSequence(scope, &tcnt, palign)
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| 			{ if (tcnt > max) max = tcnt; }
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| 	]?
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| 	END
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| 			{ *cnt = max; }
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| ]?
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| ;
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| 
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| variant(struct scope *scope; arith *cnt; struct type *tp; int *palign;)
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| {
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| 	struct node *nd;
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| } :
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| 	[
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| 		CaseLabelList(&tp, &nd)
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| 			{ /* Ignore the cases for the time being.
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| 			     Maybe a checking version will be supplied
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| 			     later ??? (Improbable)
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| 			  */
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| 			  FreeNode(nd);
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| 			}
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| 		':' FieldListSequence(scope, cnt, palign)
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| 	]?
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| 			/* Changed rule in new modula-2 */
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| ;
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| 
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| CaseLabelList(struct type **ptp; struct node **pnd;):
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| 	CaseLabels(ptp, pnd)
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| 	[	
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| 			{ *pnd = MkNode(Link, *pnd, NULLNODE, &dot); }
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| 		',' CaseLabels(ptp, &((*pnd)->nd_right))
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| 			{ pnd = &((*pnd)->nd_right); }
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| 	]*
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| ;
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| 
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| CaseLabels(struct type **ptp; register struct node **pnd;)
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| {
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| 	register struct node *nd1;
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| }:
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| 	ConstExpression(pnd)
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| 			{ nd1 = *pnd; }
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| 	[
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| 		UPTO	{ *pnd = MkNode(Link,nd1,NULLNODE,&dot); }
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| 		ConstExpression(&(*pnd)->nd_right)
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| 			{ if (!TstCompat(nd1->nd_type,
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| 					 (*pnd)->nd_right->nd_type)) {
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| 				node_error((*pnd)->nd_right,
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| 					  "type incompatibility in case label");
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| 			  	nd1->nd_type = error_type;
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| 			  }
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| 			}
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| 	]?
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| 			{ if (*ptp != 0 && !TstCompat(*ptp, nd1->nd_type)) {
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| 				node_error(nd1,
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| 					  "type incompatibility in case label");
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| 			  }
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| 			  *ptp = nd1->nd_type;
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| 			}
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| ;
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| 
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| SetType(struct type **ptp;) :
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| 	SET OF SimpleType(ptp)
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| 			{ *ptp = set_type(*ptp); }
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| ;
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| 
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| /*	In a pointer type definition, the type pointed at does not
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| 	have to be declared yet, so be careful about identifying
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| 	type-identifiers
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| */
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| PointerType(struct type **ptp;)
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| {
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| 	register struct node *nd = 0;
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| } :
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| 	POINTER TO
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| 			{ *ptp = construct_type(T_POINTER, NULLTYPE); }
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| 	[ %if	( lookup(dot.TOK_IDF, CurrentScope, 1)
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| 			/* Either a Module or a Type, but in both cases defined
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| 		   	   in this scope, so this is the correct identification
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| 			*/
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| 		||
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| 		  ( nd = new_node(),
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| 		    nd->nd_token = dot,
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| 		    lookfor(nd, CurrVis, 0)->df_kind == D_MODULE
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| 		  )
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| 			/* A Modulename in one of the enclosing scopes.
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| 			   It is not clear from the language definition that
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| 			   it is correct to handle these like this, but
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| 			   existing compilers do it like this, and the
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| 			   alternative is difficult with a lookahead of only
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| 			   one token.
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| 			   ???
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| 			*/
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| 		)
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| 	  type(&((*ptp)->next)) 
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| 			{ if (nd) free_node(nd); }
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| 	|
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| 	  IDENT		{ if (nd) {
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| 				/* nd could be a null pointer, if we had a
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| 				   syntax error exactly at this alternation.
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| 				   MORAL: Be careful with %if resolvers with
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| 				   side effects!
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| 				*/
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| 				Forward(nd, (*ptp));
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| 			  }
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| 			}
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| 	]
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| ;
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| 
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| qualtype(struct type **ptp;)
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| {
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| 	register struct node *nd;
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| 	struct node *nd1;		/* because &nd is illegal */
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| } :
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| 	qualident(&nd1)
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| 		{ nd = nd1;
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| 		  *ptp = error_type;
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| 		  if (ChkDesignator(nd)) {
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| 			if (nd->nd_class != Def) {
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| 				node_error(nd, "type expected");
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| 			}
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| 			else {
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| 				register struct def *df = nd->nd_def;
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| 
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| 				if (df->df_kind&(D_ISTYPE|D_FORWARD|D_ERROR)) {
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| 				    if (! df->df_type) {
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| node_error(nd,"type \"%s\" not (yet) declared", df->df_idf->id_text);
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| 				    }
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| 				    else *ptp = df->df_type;
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| 				}
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| 				else {
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| node_error(nd,"identifier \"%s\" is not a type", df->df_idf->id_text);
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| 				}
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| 			}
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| 		  }
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| 		  FreeNode(nd);
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| 		}
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| ;
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| 
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| ProcedureType(struct type **ptp;)
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| {
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| 	struct paramlist *pr = 0;
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| 	arith parmaddr = 0;
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| }
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| :
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| 			{ *ptp = 0; }
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| 	PROCEDURE 
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| 	[
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| 	  	FormalTypeList(&pr, &parmaddr, ptp)
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| 	]?
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| 			{ *ptp = proc_type(*ptp, pr, parmaddr); }
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| ;
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| 
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| FormalTypeList(struct paramlist **ppr; arith *parmaddr; struct type **ptp;)
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| {
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| 	struct type *tp;
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| 	int VARp;
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| } :
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| 	'('
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| 	[
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| 		var(&VARp) FormalType(&tp)
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| 			{ EnterParamList(ppr,NULLNODE,tp,VARp,parmaddr); }
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| 		[
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| 			',' var(&VARp) FormalType(&tp)
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| 			{ EnterParamList(ppr,NULLNODE,tp,VARp,parmaddr); }
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| 		]*
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| 	]?
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| 	')'
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| 	[ ':' qualtype(ptp)
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| 	]?
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| ;
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| 
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| var(int *VARp;):
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| 	VAR		{ *VARp = D_VARPAR; }
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| |
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| 	/* empty */	{ *VARp = D_VALPAR; }
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| ;
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| 
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| ConstantDeclaration
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| {
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| 	struct idf *id;
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| 	struct node *nd;
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| }:
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| 	IDENT		{ id = dot.TOK_IDF; }
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| 	'=' ConstExpression(&nd)
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| 			{ define(id,CurrentScope,D_CONST)->con_const = nd; }
 | |
| ;
 | |
| 
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| VariableDeclaration
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| {
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| 	struct node *VarList;
 | |
| 	register struct node *nd;
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| 	struct type *tp;
 | |
| } :
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| 	IdentAddr(&VarList)
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| 			{ nd = VarList; }
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| 	[ %persistent
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| 		',' IdentAddr(&(nd->nd_right))
 | |
| 			{ nd = nd->nd_right; }
 | |
| 	]*
 | |
| 	':' type(&tp)
 | |
| 			{ EnterVarList(VarList, tp, proclevel > 0); }
 | |
| ;
 | |
| 
 | |
| IdentAddr(struct node **pnd;) :
 | |
| 	IDENT		{ *pnd = MkLeaf(Name, &dot); }
 | |
| 	[	'['
 | |
| 		ConstExpression(&((*pnd)->nd_left))
 | |
| 		']'
 | |
| 	]?
 | |
| ;
 |