4.1cBSD/usr/src/ucb/pascal/src/call.c
/* Copyright (c) 1979 Regents of the University of California */
static char sccsid[] = "@(#)call.c 1.22 2/28/83";
#include "whoami.h"
#include "0.h"
#include "tree.h"
#include "opcode.h"
#include "objfmt.h"
#ifdef PC
# include "pc.h"
# include "pcops.h"
#endif PC
#include "tmps.h"
/*
* Call generates code for calls to
* user defined procedures and functions
* and is called by proc and funccod.
* P is the result of the lookup
* of the procedure/function symbol,
* and porf is PROC or FUNC.
* Psbn is the block number of p.
*
* the idea here is that regular scalar functions are just called,
* while structure functions and formal functions have their results
* stored in a temporary after the call.
* structure functions do this because they return pointers
* to static results, so we copy the static
* and return a pointer to the copy.
* formal functions do this because we have to save the result
* around a call to the runtime routine which restores the display,
* so we can't just leave the result lying around in registers.
* formal calls save the address of the descriptor in a local
* temporary, so it can be addressed for the call which restores
* the display (FRTN).
* calls to formal parameters pass the formal as a hidden argument
* to a special entry point for the formal call.
* [this is somewhat dependent on the way arguments are addressed.]
* so PROCs and scalar FUNCs look like
* p(...args...)
* structure FUNCs look like
* (temp = p(...args...),&temp)
* formal FPROCs look like
* ( t=p,( t -> entryaddr )(...args...,t,s),FRTN(t,s))
* formal scalar FFUNCs look like
* ( t=p,temp=( t -> entryaddr )(...args...,t,s),FRTN(t,s),temp)
* formal structure FFUNCs look like
* (t=p,temp = ( t -> entryaddr )(...args...,t,s),FRTN(t,s),&temp)
*/
struct nl *
call(p, argv, porf, psbn)
struct nl *p;
int *argv, porf, psbn;
{
register struct nl *p1, *q;
int *r;
struct nl *p_type_class = classify( p -> type );
bool chk = TRUE;
struct nl *savedispnp; /* temporary to hold saved display */
# ifdef PC
long p_p2type = p2type( p );
long p_type_p2type = p2type( p -> type );
bool noarguments;
long calltype; /* type of the call */
/*
* these get used if temporaries and structures are used
*/
struct nl *tempnlp;
long temptype; /* type of the temporary */
long p_type_width;
long p_type_align;
char extname[ BUFSIZ ];
struct nl *tempdescrp;
# endif PC
if (p->class == FFUNC || p->class == FPROC) {
/*
* allocate space to save the display for formal calls
*/
savedispnp = tmpalloc( sizeof display , NIL , NOREG );
}
# ifdef OBJ
if (p->class == FFUNC || p->class == FPROC) {
put(2, O_LV | cbn << 8 + INDX ,
(int) savedispnp -> value[ NL_OFFS ] );
put(2, PTR_RV | psbn << 8+INDX, (int)p->value[NL_OFFS]);
}
if (porf == FUNC) {
/*
* Push some space
* for the function return type
*/
put(2, O_PUSH, leven(-lwidth(p->type)));
}
# endif OBJ
# ifdef PC
/*
* if this is a formal call,
* stash the address of the descriptor
* in a temporary so we can find it
* after the FCALL for the call to FRTN
*/
if ( p -> class == FFUNC || p -> class == FPROC ) {
tempdescrp = tmpalloc(sizeof( struct formalrtn *) , NIL ,
REGOK );
putRV( 0 , cbn , tempdescrp -> value[ NL_OFFS ] ,
tempdescrp -> extra_flags , P2PTR|P2STRTY );
putRV( 0 , psbn , p -> value[ NL_OFFS ] ,
p -> extra_flags , P2PTR|P2STRTY );
putop( P2ASSIGN , P2PTR | P2STRTY );
}
/*
* if we have to store a temporary,
* temptype will be its type,
* otherwise, it's P2UNDEF.
*/
temptype = P2UNDEF;
calltype = P2INT;
if ( porf == FUNC ) {
p_type_width = width( p -> type );
switch( p_type_class ) {
case TSTR:
case TSET:
case TREC:
case TFILE:
case TARY:
calltype = temptype = P2STRTY;
p_type_align = align( p -> type );
break;
default:
if ( p -> class == FFUNC ) {
calltype = temptype = p2type( p -> type );
}
break;
}
if ( temptype != P2UNDEF ) {
tempnlp = tmpalloc(p_type_width, p -> type, NOREG);
/*
* temp
* for (temp = ...
*/
putRV( 0 , cbn , tempnlp -> value[ NL_OFFS ] ,
tempnlp -> extra_flags , temptype );
}
}
switch ( p -> class ) {
case FUNC:
case PROC:
/*
* ... p( ...
*/
sextname( extname , p -> symbol , BLOCKNO(p -> nl_block) );
putleaf( P2ICON , 0 , 0 , p2type( p ) , extname );
break;
case FFUNC:
case FPROC:
/*
* ... ( t -> entryaddr )( ...
*/
putRV( 0 , cbn , tempdescrp -> value[ NL_OFFS ] ,
tempdescrp -> extra_flags , P2PTR | P2STRTY );
if ( FENTRYOFFSET != 0 ) {
putleaf( P2ICON , FENTRYOFFSET , 0 , P2INT , 0 );
putop( P2PLUS ,
ADDTYPE(
ADDTYPE( ADDTYPE( p2type( p ) , P2FTN ) ,
P2PTR ) ,
P2PTR ) );
}
putop( P2UNARY P2MUL ,
ADDTYPE( ADDTYPE( p2type( p ) , P2FTN ) , P2PTR ) );
break;
default:
panic("call class");
}
noarguments = TRUE;
# endif PC
/*
* Loop and process each of
* arguments to the proc/func.
* ... ( ... args ... ) ...
*/
for (p1 = plist(p); p1 != NIL; p1 = p1->chain) {
if (argv == NIL) {
error("Not enough arguments to %s", p->symbol);
return (NIL);
}
switch (p1->class) {
case REF:
/*
* Var parameter
*/
r = argv[1];
if (r != NIL && r[0] != T_VAR) {
error("Expression given (variable required) for var parameter %s of %s", p1->symbol, p->symbol);
chk = FALSE;
break;
}
q = lvalue( (int *) argv[1], MOD | ASGN , LREQ );
if (q == NIL) {
chk = FALSE;
break;
}
if (q != p1->type) {
error("Parameter type not identical to type of var parameter %s of %s", p1->symbol, p->symbol);
chk = FALSE;
break;
}
break;
case VAR:
/*
* Value parameter
*/
# ifdef OBJ
q = rvalue(argv[1], p1->type , RREQ );
# endif OBJ
# ifdef PC
/*
* structure arguments require lvalues,
* scalars use rvalue.
*/
switch( classify( p1 -> type ) ) {
case TFILE:
case TARY:
case TREC:
case TSET:
case TSTR:
q = stkrval( argv[1] , p1 -> type , LREQ );
break;
case TINT:
case TSCAL:
case TBOOL:
case TCHAR:
precheck( p1 -> type , "_RANG4" , "_RSNG4" );
q = stkrval( argv[1] , p1 -> type , RREQ );
postcheck(p1 -> type, nl+T4INT);
break;
case TDOUBLE:
q = stkrval( argv[1] , p1 -> type , RREQ );
sconv(p2type(q), P2DOUBLE);
break;
default:
q = rvalue( argv[1] , p1 -> type , RREQ );
break;
}
# endif PC
if (q == NIL) {
chk = FALSE;
break;
}
if (incompat(q, p1->type, argv[1])) {
cerror("Expression type clashed with type of value parameter %s of %s", p1->symbol, p->symbol);
chk = FALSE;
break;
}
# ifdef OBJ
if (isa(p1->type, "bcsi"))
rangechk(p1->type, q);
if (q->class != STR)
convert(q, p1->type);
# endif OBJ
# ifdef PC
switch( classify( p1 -> type ) ) {
case TFILE:
case TARY:
case TREC:
case TSET:
case TSTR:
putstrop( P2STARG
, p2type( p1 -> type )
, lwidth( p1 -> type )
, align( p1 -> type ) );
}
# endif PC
break;
case FFUNC:
/*
* function parameter
*/
q = flvalue( (int *) argv[1] , p1 );
chk = (chk && fcompat(q, p1));
break;
case FPROC:
/*
* procedure parameter
*/
q = flvalue( (int *) argv[1] , p1 );
chk = (chk && fcompat(q, p1));
break;
default:
panic("call");
}
# ifdef PC
/*
* if this is the nth (>1) argument,
* hang it on the left linear list of arguments
*/
if ( noarguments ) {
noarguments = FALSE;
} else {
putop( P2LISTOP , P2INT );
}
# endif PC
argv = argv[2];
}
if (argv != NIL) {
error("Too many arguments to %s", p->symbol);
rvlist(argv);
return (NIL);
}
if (chk == FALSE)
return NIL;
# ifdef OBJ
if ( p -> class == FFUNC || p -> class == FPROC ) {
put(2, PTR_RV | psbn << 8+INDX, (int)p->value[NL_OFFS]);
put(2, O_LV | cbn << 8 + INDX ,
(int) savedispnp -> value[ NL_OFFS ] );
put(1, O_FCALL);
put(2, O_FRTN, even(width(p->type)));
} else {
put(2, O_CALL | psbn << 8, (long)p->value[NL_ENTLOC]);
}
# endif OBJ
# ifdef PC
/*
* for formal calls: add the hidden argument
* which is the formal struct describing the
* environment of the routine.
* and the argument which is the address of the
* space into which to save the display.
*/
if ( p -> class == FFUNC || p -> class == FPROC ) {
putRV( 0 , cbn , tempdescrp -> value[ NL_OFFS ] ,
tempdescrp -> extra_flags , P2PTR|P2STRTY );
if ( !noarguments ) {
putop( P2LISTOP , P2INT );
}
noarguments = FALSE;
putLV( 0 , cbn , savedispnp -> value[ NL_OFFS ] ,
savedispnp -> extra_flags , P2PTR | P2STRTY );
putop( P2LISTOP , P2INT );
}
/*
* do the actual call:
* either ... p( ... ) ...
* or ... ( t -> entryaddr )( ... ) ...
* and maybe an assignment.
*/
if ( porf == FUNC ) {
switch ( p_type_class ) {
case TBOOL:
case TCHAR:
case TINT:
case TSCAL:
case TDOUBLE:
case TPTR:
putop( ( noarguments ? P2UNARY P2CALL : P2CALL ) ,
p_type_p2type );
if ( p -> class == FFUNC ) {
putop( P2ASSIGN , p_type_p2type );
}
break;
default:
putstrop( ( noarguments ? P2UNARY P2STCALL : P2STCALL ),
ADDTYPE( p_type_p2type , P2PTR ) ,
p_type_width , p_type_align );
putstrop( P2STASG , p_type_p2type , lwidth( p -> type )
, align( p -> type ) );
break;
}
} else {
putop( ( noarguments ? P2UNARY P2CALL : P2CALL ) , P2INT );
}
/*
* ( t=p , ... , FRTN( t ) ...
*/
if ( p -> class == FFUNC || p -> class == FPROC ) {
putop( P2COMOP , P2INT );
putleaf( P2ICON , 0 , 0 , ADDTYPE( P2FTN | P2INT , P2PTR ) ,
"_FRTN" );
putRV( 0 , cbn , tempdescrp -> value[ NL_OFFS ] ,
tempdescrp -> extra_flags , P2PTR | P2STRTY );
putLV( 0 , cbn , savedispnp -> value[ NL_OFFS ] ,
savedispnp -> extra_flags , P2PTR | P2STRTY );
putop( P2LISTOP , P2INT );
putop( P2CALL , P2INT );
putop( P2COMOP , P2INT );
}
/*
* if required:
* either ... , temp )
* or ... , &temp )
*/
if ( porf == FUNC && temptype != P2UNDEF ) {
if ( temptype != P2STRTY ) {
putRV( 0 , cbn , tempnlp -> value[ NL_OFFS ] ,
tempnlp -> extra_flags , p_type_p2type );
} else {
putLV( 0 , cbn , tempnlp -> value[ NL_OFFS ] ,
tempnlp -> extra_flags , p_type_p2type );
}
putop( P2COMOP , P2INT );
}
if ( porf == PROC ) {
putdot( filename , line );
}
# endif PC
return (p->type);
}
rvlist(al)
register int *al;
{
for (; al != NIL; al = al[2])
rvalue( (int *) al[1], NLNIL , RREQ );
}
/*
* check that two function/procedure namelist entries are compatible
*/
bool
fcompat( formal , actual )
struct nl *formal;
struct nl *actual;
{
register struct nl *f_chain;
register struct nl *a_chain;
bool compat = TRUE;
if ( formal == NIL || actual == NIL ) {
return FALSE;
}
for (a_chain = plist(actual), f_chain = plist(formal);
f_chain != NIL;
f_chain = f_chain->chain, a_chain = a_chain->chain) {
if (a_chain == NIL) {
error("%s %s declared on line %d has more arguments than",
parnam(formal->class), formal->symbol,
linenum(formal));
cerror("%s %s declared on line %d",
parnam(actual->class), actual->symbol,
linenum(actual));
return FALSE;
}
if ( a_chain -> class != f_chain -> class ) {
error("%s parameter %s of %s declared on line %d is not identical",
parnam(f_chain->class), f_chain->symbol,
formal->symbol, linenum(formal));
cerror("with %s parameter %s of %s declared on line %d",
parnam(a_chain->class), a_chain->symbol,
actual->symbol, linenum(actual));
compat = FALSE;
} else if (a_chain->class == FFUNC || a_chain->class == FPROC) {
compat = (compat && fcompat(f_chain, a_chain));
}
if ((a_chain->class != FPROC && f_chain->class != FPROC) &&
(a_chain->type != f_chain->type)) {
error("Type of %s parameter %s of %s declared on line %d is not identical",
parnam(f_chain->class), f_chain->symbol,
formal->symbol, linenum(formal));
cerror("to type of %s parameter %s of %s declared on line %d",
parnam(a_chain->class), a_chain->symbol,
actual->symbol, linenum(actual));
compat = FALSE;
}
}
if (a_chain != NIL) {
error("%s %s declared on line %d has fewer arguments than",
parnam(formal->class), formal->symbol,
linenum(formal));
cerror("%s %s declared on line %d",
parnam(actual->class), actual->symbol,
linenum(actual));
return FALSE;
}
return compat;
}
char *
parnam(nltype)
int nltype;
{
switch(nltype) {
case REF:
return "var";
case VAR:
return "value";
case FUNC:
case FFUNC:
return "function";
case PROC:
case FPROC:
return "procedure";
default:
return "SNARK";
}
}
plist(p)
struct nl *p;
{
switch (p->class) {
case FFUNC:
case FPROC:
return p->ptr[ NL_FCHAIN ];
case PROC:
case FUNC:
return p->chain;
default:
panic("plist");
}
}
linenum(p)
struct nl *p;
{
if (p->class == FUNC)
return p->ptr[NL_FVAR]->value[NL_LINENO];
return p->value[NL_LINENO];
}