ack/lang/m2/comp/declar.g
1986-07-08 14:59:02 +00:00

543 lines
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Plaintext

/* D E C L A R A T I O N S */
{
#ifndef NORCSID
static char *RcsId = "$Header$";
#endif
#include "debug.h"
#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"
#include "main.h"
#include "chk_expr.h"
int proclevel = 0; /* nesting level of procedures */
int return_occurred; /* set if a return occurred in a
procedure or function
*/
}
ProcedureDeclaration
{
register struct def *df;
struct def *df1;
} :
{ ++proclevel;
return_occurred = 0;
}
ProcedureHeading(&df1, D_PROCEDURE)
{ CurrentScope->sc_definedby = df = df1;
df->prc_vis = CurrVis;
}
';' block(&(df->prc_body)) IDENT
{ match_id(dot.TOK_IDF, df->df_idf);
close_scope(SC_CHKFORW|SC_REVERSE);
if (! return_occurred && ResultType(df->df_type)) {
error("function procedure %s does not return a value", df->df_idf->id_text);
}
--proclevel;
}
;
ProcedureHeading(struct def **pdf; int type;)
{
struct paramlist *params = 0;
struct type *tp = 0;
register struct def *df;
arith NBytesParams;
} :
PROCEDURE IDENT
{ df = DeclProc(type);
if (proclevel > 1) { /* need room for static link */
NBytesParams = pointer_size;
}
else NBytesParams = 0;
}
FormalParameters(&params, &tp, &NBytesParams)?
{ tp = construct_type(T_PROCEDURE, tp);
tp->prc_params = params;
tp->prc_nbpar = NBytesParams;
if (df->df_type) {
/* We already saw a definition of this type
in the definition module.
*/
if (!TstProcEquiv(tp, df->df_type)) {
error("inconsistent procedure declaration for \"%s\"", df->df_idf->id_text);
}
FreeType(df->df_type);
}
df->df_type = tp;
*pdf = df;
}
;
block(struct node **pnd;) :
declaration*
[
BEGIN
StatementSequence(pnd)
|
{ *pnd = 0; }
]
END
;
declaration:
CONST [ ConstantDeclaration ';' ]*
|
TYPE [ TypeDeclaration ';' ]*
|
VAR [ VariableDeclaration ';' ]*
|
ProcedureDeclaration ';'
|
ModuleDeclaration ';'
;
FormalParameters(struct paramlist **pr;
struct type **ptp;
arith *parmaddr;)
{
struct def *df;
} :
'('
[
FPSection(pr, parmaddr)
[
';' FPSection(pr, parmaddr)
]*
]?
')'
[ ':' qualtype(ptp)
]?
;
FPSection(struct paramlist **ppr; arith *parmaddr;)
{
struct node *FPList;
struct type *tp;
int VARp;
struct paramlist *p = 0;
} :
var(&VARp) IdentList(&FPList) ':' FormalType(&p, 0)
{ EnterParamList(ppr, FPList, p->par_def->df_type,
VARp, parmaddr);
free_def(p->par_def);
free_paramlist(p);
}
;
FormalType(struct paramlist **ppr; int VARp;)
{
register struct def *df;
int ARRAYflag;
register struct type *tp;
struct type *tp1;
register struct paramlist *p = new_paramlist();
extern arith ArrayElSize();
} :
[ ARRAY OF { ARRAYflag = 1; }
| { ARRAYflag = 0; }
]
qualtype(&tp1)
{ if (ARRAYflag) {
tp = construct_type(T_ARRAY, NULLTYPE);
tp->arr_elem = tp1;
tp->arr_elsize = ArrayElSize(tp1);
tp->tp_align = lcm(word_align, pointer_align);
}
else tp = tp1;
p->next = *ppr;
*ppr = p;
p->par_def = df = new_def();
df->df_type = tp;
df->df_flags = VARp;
}
;
TypeDeclaration
{
register struct def *df;
struct type *tp;
}:
IDENT { df = define(dot.TOK_IDF,CurrentScope,D_TYPE); }
'=' type(&tp)
{ if (df->df_type && df->df_type->tp_fund == T_HIDDEN) {
if (tp->tp_fund != T_POINTER) {
error("opaque type \"%s\" is not a pointer type", df->df_idf->id_text);
}
/* Careful now ... we might have declarations
referring to the hidden type.
*/
*(df->df_type) = *tp;
free_type(tp);
}
else df->df_type = tp;
}
;
type(struct type **ptp;):
SimpleType(ptp)
|
ArrayType(ptp)
|
RecordType(ptp)
|
SetType(ptp)
|
PointerType(ptp)
|
ProcedureType(ptp)
;
SimpleType(struct type **ptp;)
{
struct type *tp;
} :
qualtype(ptp)
[
/* nothing */
|
SubrangeType(&tp)
/* The subrange type is given a base type by the
qualident (this is new modula-2).
*/
{ chk_basesubrange(tp, *ptp); }
]
|
enumeration(ptp)
|
SubrangeType(ptp)
;
enumeration(struct type **ptp;)
{
struct node *EnumList;
register struct type *tp;
} :
'(' IdentList(&EnumList) ')'
{ *ptp = tp = standard_type(T_ENUMERATION, 1, (arith) 1);
EnterEnumList(EnumList, tp);
if (tp->enm_ncst > 256) { /* ??? is this reasonable ??? */
error("Too many enumeration literals");
}
}
;
IdentList(struct node **p;)
{
register struct node *q;
} :
IDENT { *p = q = MkLeaf(Value, &dot); }
[
',' IDENT
{ q->next = MkLeaf(Value, &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->arr_elem = construct_type(T_ARRAY, tp);
tp2 = tp2->arr_elem;
}
]* OF type(&tp)
{ tp2->arr_elem = tp;
ArraySizes(*ptp);
}
;
RecordType(struct type **ptp;)
{
register 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, WA(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;
register struct idf *id = gen_anon_idf();
register struct def *df;
struct type *tp;
struct node *nd;
arith tcnt, max;
} :
[
IdentList(&FldList) ':' type(&tp)
{ *palign = lcm(*palign, tp->tp_align);
EnterFieldList(FldList, tp, scope, cnt);
}
|
CASE
/* Also accept old fashioned Modula-2 syntax, but give a warning
*/
[ qualident(0, (struct def **) 0, (char *) 0, &nd)
[ ':' qualtype(&tp)
/* This is correct, in both kinds of Modula-2, if
the first qualident is a single identifier.
*/
{ if (nd->nd_class != Name) {
error("illegal variant tag");
}
else id = nd->nd_IDF;
}
|
/* Old fashioned! the first qualident now represents
the type
*/
{ warning("Old fashioned Modula-2 syntax!");
if (chk_designator(nd) &&
(nd->nd_class != Def ||
!(nd->nd_def->df_kind&(D_ERROR|D_ISTYPE)) ||
!nd->nd_def->df_type)) {
node_error(nd, "type expected");
tp = error_type;
}
else tp = nd->nd_def->df_type;
FreeNode(nd);
}
]
|
/* Aha, third edition. Well done! */
':' qualtype(&tp)
]
{ if (!(tp->tp_fund & T_DISCRETE)) {
error("Illegal type in variant");
}
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;
df->df_flags |= D_QEXPORTED;
}
OF variant(scope, &tcnt, tp, palign)
{ max = tcnt; tcnt = *cnt; }
[
'|' variant(scope, &tcnt, tp, palign)
{ if (tcnt > max) max = tcnt; tcnt = *cnt; }
]*
[ 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;)
{
} :
SET OF SimpleType(ptp)
{ *ptp = set_type(*ptp); }
;
/* 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;)
{
register struct def *df;
register struct node *nd;
} :
POINTER TO
{ *ptp = construct_type(T_POINTER, NULLTYPE); }
[ %if ( 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
*/
qualtype(&((*ptp)->next))
| %if ( nd = new_node(), nd->nd_token = dot,
df = lookfor(nd, CurrVis, 0), free_node(nd),
df->df_kind == D_MODULE)
type(&((*ptp)->next))
|
IDENT { Forward(&dot, &((*ptp)->next)); }
]
;
qualtype(struct type **ptp;)
{
struct def *df;
} :
qualident(D_ISTYPE, &df, "type", (struct node **) 0)
{ if (!df->df_type) {
error("type \"%s\" not declared", df->df_idf->id_text);
*ptp = error_type;
}
else *ptp = df->df_type;
}
;
ProcedureType(struct type **ptp;)
{
struct paramlist *pr = 0;
register struct type *tp;
} :
{ *ptp = 0; }
PROCEDURE FormalTypeList(&pr, ptp)?
{ *ptp = tp = construct_type(T_PROCEDURE, *ptp);
tp->prc_params = pr;
}
;
FormalTypeList(struct paramlist **ppr; struct type **ptp;)
{
struct def *df;
int VARp;
} :
'(' { *ppr = 0; }
[
var(&VARp) FormalType(ppr, VARp)
[
',' var(&VARp) FormalType(ppr, VARp)
]*
]?
')'
[ ':' qualtype(ptp)
]?
;
var(int *VARp;):
VAR { *VARp = D_VARPAR; }
|
/* empty */ { *VARp = D_VALPAR; }
;
ConstantDeclaration
{
struct idf *id;
struct node *nd;
}:
IDENT { id = dot.TOK_IDF; }
'=' ConstExpression(&nd)
{ define(id,CurrentScope,D_CONST)->con_const = nd; }
;
VariableDeclaration
{
struct node *VarList;
register struct node *nd;
struct type *tp;
} :
IdentAddr(&VarList)
{ nd = VarList; }
[
',' 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))?
;