586 lines
12 KiB
C
586 lines
12 KiB
C
/* P A R S E T R E E W A L K E R */
|
|
|
|
#ifndef NORCSID
|
|
static char *RcsId = "$Header$";
|
|
#endif
|
|
|
|
/* Routines to walk through parts of the parse tree, and generate
|
|
code for these parts.
|
|
*/
|
|
|
|
#include "debug.h"
|
|
|
|
#include <em_arith.h>
|
|
#include <em_label.h>
|
|
#include <assert.h>
|
|
|
|
#include "def.h"
|
|
#include "type.h"
|
|
#include "scope.h"
|
|
#include "main.h"
|
|
#include "LLlex.h"
|
|
#include "node.h"
|
|
#include "Lpars.h"
|
|
#include "desig.h"
|
|
#include "f_info.h"
|
|
#include "idf.h"
|
|
|
|
extern arith NewPtr();
|
|
extern arith NewInt();
|
|
extern int proclevel;
|
|
static label instructionlabel;
|
|
static char return_expr_occurred;
|
|
static struct type *func_type;
|
|
struct withdesig *WithDesigs;
|
|
struct node *Modules;
|
|
|
|
label
|
|
text_label()
|
|
{
|
|
return instructionlabel++;
|
|
}
|
|
|
|
label
|
|
data_label()
|
|
{
|
|
static label datalabel = 0;
|
|
|
|
return ++datalabel;
|
|
}
|
|
|
|
static
|
|
DoProfil()
|
|
{
|
|
static label filename_label = 0;
|
|
|
|
if (! options['L']) {
|
|
if (!filename_label) {
|
|
filename_label = data_label();
|
|
C_df_dlb(filename_label);
|
|
C_rom_scon(FileName, (arith) (strlen(FileName) + 1));
|
|
}
|
|
|
|
C_fil_dlb(filename_label, (arith) 0);
|
|
}
|
|
}
|
|
|
|
WalkModule(module)
|
|
register struct def *module;
|
|
{
|
|
/* Walk through a module, and all its local definitions.
|
|
Also generate code for its body.
|
|
*/
|
|
register struct def *df = module->mod_vis->sc_scope->sc_def;
|
|
register struct scope *sc;
|
|
struct scopelist *vis;
|
|
|
|
vis = CurrVis;
|
|
CurrVis = module->mod_vis;
|
|
sc = CurrentScope;
|
|
|
|
if (!proclevel) {
|
|
/* This module is a glocal module.
|
|
Generate code to allocate storage for its variables.
|
|
They all have an explicit name.
|
|
*/
|
|
while (df) {
|
|
if (df->df_kind == D_VARIABLE) {
|
|
C_df_dnam(df->var_name);
|
|
C_bss_cst(
|
|
align(df->df_type->tp_size, word_align),
|
|
(arith) 0, 0);
|
|
}
|
|
df = df->df_nextinscope;
|
|
}
|
|
if (state == PROGRAM) C_exp("main");
|
|
else C_exp(sc->sc_name);
|
|
}
|
|
|
|
/* Now, walk through it's local definitions
|
|
*/
|
|
WalkDef(sc->sc_def);
|
|
|
|
/* Now, generate initialization code for this module.
|
|
First call initialization routines for modules defined within
|
|
this module.
|
|
*/
|
|
sc->sc_off = 0;
|
|
instructionlabel = 2;
|
|
func_type = 0;
|
|
C_pro_narg(state == PROGRAM ? "main" : sc->sc_name);
|
|
DoProfil();
|
|
if (CurrVis == Defined->mod_vis) {
|
|
/* Body of implementation or program module.
|
|
Call initialization routines of imported modules.
|
|
Also prevent recursive calls of this one.
|
|
*/
|
|
struct node *nd;
|
|
|
|
if (state == IMPLEMENTATION) {
|
|
label l1 = data_label(), l2 = text_label();
|
|
/* we don't actually prevent recursive calls,
|
|
but do nothing if called recursively
|
|
*/
|
|
C_df_dlb(l1);
|
|
C_bss_cst(word_size, (arith) 0, 1);
|
|
C_loe_dlb(l1, (arith) 0);
|
|
C_zeq(l2);
|
|
C_ret((arith) 0);
|
|
C_df_ilb(l2);
|
|
C_loc((arith) 1);
|
|
C_ste_dlb(l1, (arith) 0);
|
|
}
|
|
|
|
nd = Modules;
|
|
while (nd) {
|
|
C_cal(nd->nd_IDF->id_text);
|
|
nd = nd->next;
|
|
}
|
|
}
|
|
MkCalls(sc->sc_def);
|
|
proclevel++;
|
|
WalkNode(module->mod_body, (label) 0);
|
|
C_df_ilb((label) 1);
|
|
C_ret((arith) 0);
|
|
C_end(-sc->sc_off);
|
|
proclevel--;
|
|
TmpClose();
|
|
|
|
CurrVis = vis;
|
|
}
|
|
|
|
WalkProcedure(procedure)
|
|
register struct def *procedure;
|
|
{
|
|
/* Walk through the definition of a procedure and all its
|
|
local definitions
|
|
*/
|
|
struct scopelist *vis = CurrVis;
|
|
register struct scope *sc;
|
|
register struct type *res_type;
|
|
|
|
proclevel++;
|
|
CurrVis = procedure->prc_vis;
|
|
sc = CurrentScope;
|
|
|
|
WalkDef(sc->sc_def);
|
|
|
|
/* Generate code for this procedure
|
|
*/
|
|
C_pro_narg(sc->sc_name);
|
|
DoProfil();
|
|
/* generate calls to initialization routines of modules defined within
|
|
this procedure
|
|
*/
|
|
MkCalls(sc->sc_def);
|
|
return_expr_occurred = 0;
|
|
instructionlabel = 2;
|
|
func_type = res_type = procedure->df_type->next;
|
|
if (! returntype(res_type)) {
|
|
node_error(procedure->prc_body, "illegal result type");
|
|
}
|
|
WalkNode(procedure->prc_body, (label) 0);
|
|
C_df_ilb((label) 1);
|
|
if (res_type) {
|
|
if (! return_expr_occurred) {
|
|
node_error(procedure->prc_body,"function procedure does not return a value");
|
|
}
|
|
C_ret(align(res_type->tp_size, word_align));
|
|
}
|
|
else C_ret((arith) 0);
|
|
C_end(-sc->sc_off);
|
|
TmpClose();
|
|
CurrVis = vis;
|
|
proclevel--;
|
|
}
|
|
|
|
WalkDef(df)
|
|
register struct def *df;
|
|
{
|
|
/* Walk through a list of definitions
|
|
*/
|
|
|
|
while (df) {
|
|
if (df->df_kind == D_MODULE) {
|
|
WalkModule(df);
|
|
}
|
|
else if (df->df_kind == D_PROCEDURE) {
|
|
WalkProcedure(df);
|
|
}
|
|
df = df->df_nextinscope;
|
|
}
|
|
}
|
|
|
|
MkCalls(df)
|
|
register struct def *df;
|
|
{
|
|
/* Generate calls to initialization routines of modules
|
|
*/
|
|
|
|
while (df) {
|
|
if (df->df_kind == D_MODULE) {
|
|
C_lxl((arith) 0);
|
|
C_cal(df->mod_vis->sc_scope->sc_name);
|
|
C_asp(pointer_size);
|
|
}
|
|
df = df->df_nextinscope;
|
|
}
|
|
}
|
|
|
|
WalkNode(nd, lab)
|
|
register struct node *nd;
|
|
label lab;
|
|
{
|
|
/* Node "nd" represents either a statement or a statement list.
|
|
Walk through it.
|
|
"lab" represents the label that must be jumped to on
|
|
encountering an EXIT statement.
|
|
*/
|
|
|
|
while (nd->nd_class == Link) { /* statement list */
|
|
WalkStat(nd->nd_left, lab);
|
|
nd = nd->nd_right;
|
|
}
|
|
|
|
WalkStat(nd, lab);
|
|
}
|
|
|
|
WalkStat(nd, lab)
|
|
struct node *nd;
|
|
label lab;
|
|
{
|
|
/* Walk through a statement, generating code for it.
|
|
"lab" represents the label that must be jumped to on
|
|
encountering an EXIT statement.
|
|
*/
|
|
register struct node *left = nd->nd_left;
|
|
register struct node *right = nd->nd_right;
|
|
register struct desig *pds = &Desig;
|
|
|
|
if (!nd) {
|
|
/* Empty statement
|
|
*/
|
|
return;
|
|
}
|
|
|
|
if (! options['L']) C_lin((arith) nd->nd_lineno);
|
|
|
|
if (nd->nd_class == Call) {
|
|
if (chk_call(nd)) {
|
|
if (nd->nd_type != 0) {
|
|
node_error(nd, "procedure call expected");
|
|
return;
|
|
}
|
|
CodeCall(nd);
|
|
}
|
|
return;
|
|
}
|
|
|
|
assert(nd->nd_class == Stat);
|
|
|
|
switch(nd->nd_symb) {
|
|
case BECOMES:
|
|
DoAssign(nd, left, right);
|
|
break;
|
|
|
|
case IF:
|
|
{ label l1, l2, l3;
|
|
|
|
l1 = instructionlabel++;
|
|
l2 = instructionlabel++;
|
|
l3 = instructionlabel++;
|
|
ExpectBool(left, l3, l1);
|
|
assert(right->nd_symb == THEN);
|
|
C_df_ilb(l3);
|
|
WalkNode(right->nd_left, lab);
|
|
|
|
if (right->nd_right) { /* ELSE part */
|
|
C_bra(l2);
|
|
C_df_ilb(l1);
|
|
WalkNode(right->nd_right, lab);
|
|
C_df_ilb(l2);
|
|
}
|
|
else C_df_ilb(l1);
|
|
break;
|
|
}
|
|
|
|
case CASE:
|
|
CaseCode(nd, lab);
|
|
break;
|
|
|
|
case WHILE:
|
|
{ label l1, l2, l3;
|
|
|
|
l1 = instructionlabel++;
|
|
l2 = instructionlabel++;
|
|
l3 = instructionlabel++;
|
|
C_df_ilb(l1);
|
|
ExpectBool(left, l3, l2);
|
|
C_df_ilb(l3);
|
|
WalkNode(right, lab);
|
|
C_bra(l1);
|
|
C_df_ilb(l2);
|
|
break;
|
|
}
|
|
|
|
case REPEAT:
|
|
{ label l1, l2;
|
|
|
|
l1 = instructionlabel++;
|
|
l2 = instructionlabel++;
|
|
C_df_ilb(l1);
|
|
WalkNode(left, lab);
|
|
ExpectBool(right, l2, l1);
|
|
C_df_ilb(l2);
|
|
break;
|
|
}
|
|
|
|
case LOOP:
|
|
{ label l1, l2;
|
|
|
|
l1 = instructionlabel++;
|
|
l2 = instructionlabel++;
|
|
C_df_ilb(l1);
|
|
WalkNode(left, l2);
|
|
C_bra(l1);
|
|
C_df_ilb(l2);
|
|
break;
|
|
}
|
|
|
|
case FOR:
|
|
{
|
|
arith tmp = 0;
|
|
struct node *fnd;
|
|
label l1 = instructionlabel++;
|
|
label l2 = instructionlabel++;
|
|
|
|
if (! DoForInit(nd, left)) break;
|
|
fnd = left->nd_right;
|
|
if (fnd->nd_class != Value) {
|
|
CodePExpr(fnd);
|
|
tmp = NewInt();
|
|
C_stl(tmp);
|
|
}
|
|
C_bra(l1);
|
|
C_df_ilb(l2);
|
|
WalkNode(right, lab);
|
|
C_loc(left->nd_INT);
|
|
CodePExpr(nd);
|
|
C_adi(int_size);
|
|
CodeDStore(nd);
|
|
C_df_ilb(l1);
|
|
CodePExpr(nd);
|
|
if (tmp) C_lol(tmp); else C_loc(fnd->nd_INT);
|
|
if (left->nd_INT > 0) {
|
|
C_ble(l2);
|
|
}
|
|
else C_bge(l2);
|
|
if (tmp) FreeInt(tmp);
|
|
}
|
|
break;
|
|
|
|
case WITH:
|
|
{
|
|
struct scopelist link;
|
|
struct withdesig wds;
|
|
arith tmp = 0;
|
|
|
|
WalkDesignator(left);
|
|
if (left->nd_type->tp_fund != T_RECORD) {
|
|
node_error(left, "record variable expected");
|
|
break;
|
|
}
|
|
|
|
wds.w_next = WithDesigs;
|
|
WithDesigs = &wds;
|
|
wds.w_scope = left->nd_type->rec_scope;
|
|
if (pds->dsg_kind != DSG_PFIXED) {
|
|
/* In this case, we use a temporary variable
|
|
*/
|
|
CodeAddress(pds);
|
|
pds->dsg_kind = DSG_FIXED;
|
|
/* Only for the store ... */
|
|
pds->dsg_offset = tmp = NewPtr();
|
|
pds->dsg_name = 0;
|
|
CodeStore(pds, pointer_size);
|
|
pds->dsg_kind = DSG_PFIXED;
|
|
/* the record is indirectly available */
|
|
}
|
|
wds.w_desig = *pds;
|
|
link.sc_scope = wds.w_scope;
|
|
link.next = CurrVis;
|
|
CurrVis = &link;
|
|
WalkNode(right, lab);
|
|
CurrVis = link.next;
|
|
WithDesigs = wds.w_next;
|
|
if (tmp) FreePtr(tmp);
|
|
break;
|
|
}
|
|
|
|
case EXIT:
|
|
assert(lab != 0);
|
|
|
|
C_bra(lab);
|
|
break;
|
|
|
|
case RETURN:
|
|
if (right) {
|
|
WalkExpr(right, NO_LABEL, NO_LABEL);
|
|
/* Assignment compatibility? Yes, see Rep. 9.11
|
|
*/
|
|
if (!TstAssCompat(func_type, right->nd_type)) {
|
|
node_error(right, "type incompatibility in RETURN statement");
|
|
}
|
|
return_expr_occurred = 1;
|
|
}
|
|
C_bra((label) 1);
|
|
break;
|
|
|
|
default:
|
|
assert(0);
|
|
}
|
|
}
|
|
|
|
ExpectBool(nd, true_label, false_label)
|
|
register struct node *nd;
|
|
label true_label, false_label;
|
|
{
|
|
/* "nd" must indicate a boolean expression. Check this and
|
|
generate code to evaluate the expression.
|
|
*/
|
|
|
|
WalkExpr(nd, true_label, false_label);
|
|
|
|
if (nd->nd_type != bool_type && nd->nd_type != error_type) {
|
|
node_error(nd, "boolean expression expected");
|
|
}
|
|
}
|
|
|
|
WalkExpr(nd, true_label, false_label)
|
|
struct node *nd;
|
|
label true_label, false_label;
|
|
{
|
|
/* Check an expression and generate code for it
|
|
*/
|
|
|
|
DO_DEBUG(1, (DumpTree(nd), print("\n")));
|
|
|
|
if (! chk_expr(nd)) return;
|
|
|
|
Desig = InitDesig;
|
|
CodeExpr(nd, &Desig, true_label, false_label);
|
|
}
|
|
|
|
WalkDesignator(nd)
|
|
struct node *nd;
|
|
{
|
|
/* Check designator and generate code for it
|
|
*/
|
|
|
|
DO_DEBUG(1, (DumpTree(nd), print("\n")));
|
|
|
|
if (! chk_designator(nd, DESIGNATOR|VARIABLE, D_DEFINED)) return;
|
|
|
|
Desig = InitDesig;
|
|
CodeDesig(nd, &Desig);
|
|
}
|
|
|
|
DoForInit(nd, left)
|
|
register struct node *nd, *left;
|
|
{
|
|
|
|
nd->nd_left = nd->nd_right = 0;
|
|
nd->nd_class = Name;
|
|
nd->nd_symb = IDENT;
|
|
|
|
if (! chk_designator(nd, VARIABLE, D_DEFINED) ||
|
|
! chk_expr(left->nd_left) ||
|
|
! chk_expr(left->nd_right)) return 0;
|
|
|
|
if (nd->nd_type->tp_size > word_size ||
|
|
!(nd->nd_type->tp_fund & T_DISCRETE)) {
|
|
node_error(nd, "illegal type of FOR loop variable");
|
|
return 0;
|
|
}
|
|
|
|
if (!TstCompat(nd->nd_type, left->nd_left->nd_type) ||
|
|
!TstCompat(nd->nd_type, left->nd_right->nd_type)) {
|
|
if (!TstAssCompat(nd->nd_type, left->nd_left->nd_type) ||
|
|
!TstAssCompat(nd->nd_type, left->nd_right->nd_type)) {
|
|
node_error(nd, "type incompatibility in FOR statement");
|
|
return 0;
|
|
}
|
|
node_warning(nd, "old-fashioned! compatibility required in FOR statement");
|
|
}
|
|
|
|
CodePExpr(left->nd_left);
|
|
CodeDStore(nd);
|
|
|
|
return 1;
|
|
}
|
|
|
|
DoAssign(nd, left, right)
|
|
struct node *nd;
|
|
register struct node *left, *right;
|
|
{
|
|
/* May we do it in this order (expression first) ??? */
|
|
struct desig ds;
|
|
|
|
if (!chk_expr(right)) return;
|
|
if (! chk_designator(left, DESIGNATOR|VARIABLE, D_DEFINED)) return;
|
|
TryToString(right, left->nd_type);
|
|
Desig = InitDesig;
|
|
CodeExpr(right, &Desig, NO_LABEL, NO_LABEL);
|
|
|
|
if (! TstAssCompat(left->nd_type, right->nd_type)) {
|
|
node_error(nd, "type incompatibility in assignment");
|
|
return;
|
|
}
|
|
|
|
if (complex(right->nd_type)) {
|
|
CodeAddress(&Desig);
|
|
}
|
|
else {
|
|
CodeValue(&Desig, right->nd_type->tp_size);
|
|
CheckAssign(left->nd_type, right->nd_type);
|
|
}
|
|
ds = Desig;
|
|
Desig = InitDesig;
|
|
CodeDesig(left, &Desig);
|
|
|
|
CodeAssign(nd, &ds, &Desig);
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
DumpTree(nd)
|
|
struct node *nd;
|
|
{
|
|
char *s;
|
|
extern char *symbol2str();
|
|
|
|
if (!nd) {
|
|
print("()");
|
|
return;
|
|
}
|
|
|
|
print("(");
|
|
DumpTree(nd->nd_left);
|
|
switch(nd->nd_class) {
|
|
case Def: s = "Def"; break;
|
|
case Oper: s = "Oper"; break;
|
|
case Uoper: s = "Uoper"; break;
|
|
case Name: s = "Name"; break;
|
|
case Set: s = "Set"; break;
|
|
case Value: s = "Value"; break;
|
|
case Call: s = "Call"; break;
|
|
case Xset: s = "Xset"; break;
|
|
case Stat: s = "Stat"; break;
|
|
case Link: s = "Link"; break;
|
|
default: s = "ERROR"; break;
|
|
}
|
|
print("%s %s", s, symbol2str(nd->nd_symb));
|
|
DumpTree(nd->nd_right);
|
|
print(")");
|
|
}
|
|
#endif
|