ack/lang/m2/comp/declar.g

/* D E C L A R A T I O N S */

{
static char *RcsId = "$Header$";

#include	<em_arith.h>
#include	<em_label.h>
#include	<alloc.h>
#include	<assert.h>
#include	"idf.h"
#include	"LLlex.h"
#include	"def.h"
#include	"type.h"
#include	"scope.h"
#include	"node.h"
#include	"misc.h"

static int	proclevel = 0;	/* nesting level of procedures */
}

ProcedureDeclaration
{
	struct def *df;
} :
	ProcedureHeading(&df, D_PROCEDURE)
			{ df->prc_level = proclevel++;
			}
	';' block(&(df->prc_body)) IDENT
			{ match_id(dot.TOK_IDF, df->df_idf);
			  df->prc_scope = CurrentScope;
			  close_scope(SC_CHKFORW);
			  proclevel--;
			}
;

ProcedureHeading(struct def **pdf; int type;)
{
	struct type *tp = 0;
	struct type *tp1 = 0;
	struct paramlist *params = 0;
	register struct def *df;
} :
	PROCEDURE IDENT
		{ assert(type & (D_PROCEDURE | D_PROCHEAD));
		  if (type == D_PROCHEAD) {
			df = define(dot.TOK_IDF, CurrentScope, type);
			df->for_node = MkNode(Name, NULLNODE, NULLNODE, &dot);
		  }
		  else {
			df = lookup(dot.TOK_IDF, CurrentScope);
			if (df && df->df_kind == D_PROCHEAD) {
				df->df_kind = type;
				tp1 = df->df_type;
			}
			else	df = define(dot.TOK_IDF, CurrentScope, type);
			df->prc_nbpar = 0;
			open_scope(OPENSCOPE);
		  }
		}
	FormalParameters(type == D_PROCEDURE, &params, &tp, &(df->prc_nbpar))?
		{
		  df->df_type = tp = construct_type(T_PROCEDURE, tp);
		  tp->prc_params = params;
		  if (tp1 && !TstTypeEquiv(tp, tp1)) {
error("inconsistent procedure declaration for \"%s\"", df->df_idf->id_text); 
		  }
		  *pdf = df;
		}
;

block(struct node **pnd;)
{
}:
	declaration*
	[
		BEGIN
		StatementSequence(pnd)
	|
			{ *pnd = 0; }
	]
	END
;

declaration:
	CONST [ ConstantDeclaration ';' ]*
|
	TYPE [ TypeDeclaration ';' ]*
|
	VAR [ VariableDeclaration ';' ]*
|
	ProcedureDeclaration ';'
|
	ModuleDeclaration ';'
;

FormalParameters(int doparams;
		 struct paramlist **pr;
		 struct type **tp;
		 arith *parmaddr;)
{
	struct def *df;
	register struct paramlist *pr1;
} :
	'('
	[
		FPSection(doparams, pr, parmaddr)	
			{ pr1 = *pr; }
		[
			{ for (; pr1->next; pr1 = pr1->next) ; }
			';' FPSection(doparams, &(pr1->next), parmaddr)
		]*
	]?
	')'
			{ *tp = 0; }
	[	':' qualident(D_TYPE|D_HTYPE|D_HIDDEN, &df, "type", (struct node **) 0)
			{ *tp = df->df_type; }
	]?
;

/*	In the next nonterminal, "doparams" is a flag indicating whether
	the identifiers representing the parameters must be added to the
	symbol table. We must not do so when reading a Definition Module,
	because in this case we only read the header. The Implementation
	might contain different identifiers representing the same paramters.
*/
FPSection(int doparams; struct paramlist **ppr; arith *addr;)
{
	struct node *FPList;
	struct paramlist *ParamList();
	struct type *tp;
	int VARp = 0;
} :
	[
		VAR	{ VARp = 1; }
	]?
	IdentList(&FPList) ':' FormalType(&tp)
		{
		  if (doparams) {
			EnterIdList(FPList, D_VARIABLE, VARp,
				    tp, CurrentScope, addr);
		  }
		  *ppr = ParamList(FPList, tp, VARp);
		  FreeNode(FPList);
		}
;

FormalType(struct type **tp;)
{
	struct def *df;
	int ARRAYflag = 0;
} :
	[ ARRAY OF	{ ARRAYflag = 1; }
	]?
	qualident(D_TYPE|D_HTYPE|D_HIDDEN, &df, "type", (struct node **) 0)
			{ if (ARRAYflag) {
				*tp = construct_type(T_ARRAY, NULLTYPE);
				(*tp)->arr_elem = df->df_type;
				(*tp)->tp_align = lcm(word_align, pointer_align);
				(*tp)->tp_size = align(pointer_size + 3*word_size,
							(*tp)->tp_align);
			  }
			  else	*tp = df->df_type;
			}
;

TypeDeclaration
{
	struct def *df;
	struct type *tp;
}:
	IDENT		{ df = define(dot.TOK_IDF, CurrentScope, D_TYPE); }
	'=' type(&tp)
			{ df->df_type = tp;
			  if ((df->df_flags&D_EXPORTED) &&
			      tp->tp_fund == T_ENUMERATION) {
				exprt_literals(tp->enm_enums,
						enclosing(CurrentScope));
			  }
			  if (df->df_kind == D_HTYPE &&
			      tp->tp_fund != T_POINTER) {
error("Opaque type \"%s\" is not a pointer type", df->df_idf->id_text);
			  }

			}
;

type(struct type **ptp;):
	SimpleType(ptp)
|
	ArrayType(ptp)
|
	RecordType(ptp)
|
	SetType(ptp)
|
	PointerType(ptp)
|
	ProcedureType(ptp)
;

SimpleType(struct type **ptp;)
{
	struct def *df;
} :
	qualident(D_TYPE|D_HTYPE|D_HIDDEN, &df, "type", (struct node **) 0)
	[
		/* nothing */
			{ *ptp = df->df_type; }
	|
		SubrangeType(ptp)
		/* The subrange type is given a base type by the
		   qualident (this is new modula-2).
		*/
			{
			  chk_basesubrange(*ptp, df->df_type);
			}
	]
|
	enumeration(ptp)
|
	SubrangeType(ptp)
;

enumeration(struct type **ptp;)
{
	struct node *EnumList;
} :
	'(' IdentList(&EnumList) ')'
		{
		  *ptp = standard_type(T_ENUMERATION, 1, (arith) 1);
		  EnterIdList(EnumList, D_ENUM, 0, *ptp,
				CurrentScope, (arith *) 0);
		  FreeNode(EnumList);
		  if ((*ptp)->enm_ncst > 256) {
			if (word_size == 1) {
				error("Too many enumeration literals");
			}
			else {
				(*ptp)->tp_size = word_size;
				(*ptp)->tp_align = word_align;
			}
		  }
		}
;

IdentList(struct node **p;)
{
	register struct node *q;
} :
	IDENT		{ q = MkNode(Value, NULLNODE, NULLNODE, &dot);
			  *p = q;
			}
	[
		',' IDENT
			{ q->next = MkNode(Value,NULLNODE,NULLNODE,&dot);
			  q = q->next;
			}
	]*
			{ q->next = 0; }
;

SubrangeType(struct type **ptp;)
{
	struct node *nd1, *nd2;
}:
	/*
	   This is not exactly the rule in the new report, but see
	   the rule for "SimpleType".
	*/
	'[' ConstExpression(&nd1)
	UPTO ConstExpression(&nd2)
	']'
			{ *ptp = subr_type(nd1, nd2); }
;

ArrayType(struct type **ptp;)
{
	struct type *tp;
	register struct type *tp2;
} :
	ARRAY SimpleType(&tp)
			{
			  *ptp = tp2 = construct_type(T_ARRAY, tp);
			}
	[
		',' SimpleType(&tp)
			{ tp2 = tp2->arr_elem = 
				construct_type(T_ARRAY, tp);
			}
	]* OF type(&tp)
			{ tp2->arr_elem = tp;
			  ArraySizes(*ptp);
			}
;

RecordType(struct type **ptp;)
{
	struct scope *scope;
	arith count;
	int xalign = struct_align;
}
:
	RECORD
			{ open_scope(OPENSCOPE);
			  scope = CurrentScope;
			  close_scope(0);
			  count = 0;
			}
	FieldListSequence(scope, &count, &xalign)
		{
		  *ptp = standard_type(T_RECORD, xalign, count);
		  (*ptp)->rec_scope = scope;
		}
	END
;

FieldListSequence(struct scope *scope; arith *cnt; int *palign;):
	FieldList(scope, cnt, palign)
	[
		';' FieldList(scope, cnt, palign)
	]*
;

FieldList(struct scope *scope; arith *cnt; int *palign;)
{
	struct node *FldList;
	struct idf *id;
	struct def *df;
	struct type *tp;
	struct node *nd;
	arith tcnt, max;
} :
[
	IdentList(&FldList) ':' type(&tp)
			{ *palign = lcm(*palign, tp->tp_align);
			  EnterIdList(FldList, D_FIELD, 0, tp, scope, cnt);
			  FreeNode(FldList);
			}
|
	CASE
	/* Also accept old fashioned Modula-2 syntax, but give a warning
	*/
	[	qualident(0, &df, (char *) 0, &nd)
		[	/* This is good, in both kinds of Modula-2, if
			   the first qualident is a single identifier.
			*/
			{ if (nd->nd_class != Name) {
				error("illegal variant tag");
				id = gen_anon_idf();
			  }
			  else	id = nd->nd_IDF;
			}
		':' qualident(D_TYPE|D_HTYPE|D_HIDDEN,
			      &df, "type", (struct node **) 0)
		|
			/* Old fashioned! the first qualident now represents
			   the type
			*/
				{ warning("Old fashioned Modula-2 syntax!");
				  id = gen_anon_idf();
				  findname(nd);
				  assert(nd->nd_class == Def);
				  df = nd->nd_def;
				  if (!(df->df_kind &
					(D_ERROR|D_TYPE|D_HTYPE|D_HIDDEN))) {
					error("identifier \"%s\" is not a type",
						df->df_idf->id_text);
				  }
				  FreeNode(nd);
				}
		]
	|
		/* Aha, third edition? */
		':' qualident(D_TYPE|D_HTYPE|D_HIDDEN, &df, "type", (struct node **) 0)
				{ id = gen_anon_idf(); }
	]
				{ tp = df->df_type;
				  df = define(id, scope, D_FIELD);
				  df->df_type = tp;
				  df->fld_off = align(*cnt, tp->tp_align);
				  *cnt = tcnt = df->fld_off + tp->tp_size;
				}
	OF variant(scope, &tcnt, tp, palign)
				{ max = tcnt; tcnt = *cnt; }
	[
		'|' variant(scope, &tcnt, tp, palign)
				{ if (tcnt > max) max = tcnt; }
	]*
	[ ELSE FieldListSequence(scope, &tcnt, palign)
				{ if (tcnt > max) max = tcnt; }
	]?
	END
				{ *cnt = max; }
]?
;

variant(struct scope *scope; arith *cnt; struct type *tp; int *palign;)
{
	struct type *tp1 = tp;
	struct node *nd;
} :
	[
		CaseLabelList(&tp1, &nd)
				{ /* Ignore the cases for the time being.
				     Maybe a checking version will be supplied
				     later ???
				  */
				  FreeNode(nd);
				}
		':' FieldListSequence(scope, cnt, palign)
	]?
					/* Changed rule in new modula-2 */
;

CaseLabelList(struct type **ptp; struct node **pnd;):
	CaseLabels(ptp, pnd)
	[	
			{ *pnd = MkNode(Link, *pnd, NULLNODE, &dot); }
		',' CaseLabels(ptp, &((*pnd)->nd_right))
			{ pnd = &((*pnd)->nd_right); }
	]*
;

CaseLabels(struct type **ptp; struct node **pnd;)
{
	struct node *nd1, *nd2 = 0;
}:
	ConstExpression(&nd1)	{ *pnd = nd1; }
	[
		UPTO		{ *pnd = MkNode(Link,nd1,NULLNODE,&dot); }
		ConstExpression(&nd2)
				{ if (!TstCompat(nd1->nd_type, nd2->nd_type)) {
node_error(nd2,"type incompatibility in case label");
				  }
				  nd1->nd_type = error_type;
				  (*pnd)->nd_right = nd2;
				}
	]?
				{ if (*ptp != 0 &&
				       !TstCompat(*ptp, nd1->nd_type)) {
node_error(nd1,"type incompatibility in case label");
				  }
				  *ptp = nd1->nd_type;
				}
;

SetType(struct type **ptp;)
{
	struct type *tp;
} :
	SET OF SimpleType(&tp)
			{ 
			  *ptp = set_type(tp);
			}
;

/*	In a pointer type definition, the type pointed at does not
	have to be declared yet, so be careful about identifying
	type-identifiers
*/
PointerType(struct type **ptp;)
{
	struct type *tp;
	struct def *df;
	struct def *lookfor();
	struct node *nd;
} :
	POINTER TO
	[ %if ( (df = lookup(dot.TOK_IDF, CurrentScope)))
		/* Either a Module or a Type, but in both cases defined
		   in this scope, so this is the correct identification
		*/
		qualident(D_TYPE|D_HTYPE|D_HIDDEN, &df, "type", (struct node **) 0)
				{
				  if (!df->df_type) {
					error("type \"%s\" not declared",
						df->df_idf->id_text);
					tp = error_type;
				  }
				  else	tp = df->df_type;
				}
	| %if ( nd = new_node(), nd->nd_token = dot,
		df = lookfor(nd, CurrentScope, 0), free_node(nd),
	        df->df_kind == D_MODULE)
		type(&tp)
	|
		IDENT
				{ tp = NULLTYPE; }
	]
				{
				  *ptp = construct_type(T_POINTER, tp);
				  if (!tp) Forward(&dot, &((*ptp)->next));
				}
;

ProcedureType(struct type **ptp;)
{
	struct paramlist *pr = 0;
	struct type *tp = 0;
} :
	PROCEDURE FormalTypeList(&pr, &tp)?
			{ *ptp = construct_type(T_PROCEDURE, tp);
			  (*ptp)->prc_params = pr;
			}
;

FormalTypeList(struct paramlist **ppr; struct type **ptp;)
{
	struct def *df;
	struct type *tp;
	struct paramlist *p;
	int VARp;
} :
	'('		{ *ppr = 0; }
	[
		[ VAR	{ VARp = 1; }
		|	{ VARp = 0; }
		]
		FormalType(&tp)
			{ *ppr = p = new_paramlist();
			  p->par_type = tp;
			  p->par_var = VARp;
			}
		[
			','
			[ VAR	{VARp = 1; }
			|	{VARp = 0; }
			] 
			FormalType(&tp)
				{ p->next = new_paramlist();
				  p = p->next;
				  p->par_type = tp;
				  p->par_var = VARp;
				}
		]*
				{ p->next = 0; }
	]?
	')'
	[ ':' qualident(D_TYPE|D_HTYPE|D_HIDDEN, &df, "type", (struct node **) 0)
				{ *ptp = df->df_type; }
	]?
;

ConstantDeclaration
{
	struct def *df;
	struct idf *id;
	struct node *nd;
}:
	IDENT			{ id = dot.TOK_IDF; }
	'=' ConstExpression(&nd){ df = define(id, CurrentScope, D_CONST);
				  df->con_const = nd;
				}
;

VariableDeclaration
{
	struct node *VarList;
	struct type *tp;
} :
	IdentAddrList(&VarList)
	':' type(&tp)
			{ EnterVarList(VarList, tp, proclevel > 0);
			  FreeNode(VarList);
			}
;

IdentAddrList(struct node **pnd;)
{
} :
	IDENT		{ *pnd = MkNode(Name, NULLNODE, NULLNODE, &dot); }
	ConstExpression(&(*pnd)->nd_left)?
	[		{ pnd = &((*pnd)->nd_right); }
		',' IDENT
			{ *pnd = MkNode(Name, NULLNODE, NULLNODE, &dot); }
		ConstExpression(&(*pnd)->nd_left)?
	]*
;