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

337 lines
6.9 KiB
C

/* D E F I N I T I O N M E C H A N I S M */
#ifndef NORCSID
static char *RcsId = "$Header$";
#endif
#include "debug.h"
#include <alloc.h>
#include <em_arith.h>
#include <em_label.h>
#include <assert.h>
#include "main.h"
#include "def.h"
#include "type.h"
#include "idf.h"
#include "scope.h"
#include "LLlex.h"
#include "node.h"
#include "Lpars.h"
struct def *h_def; /* pointer to free list of def structures */
#ifdef DEBUG
int cnt_def; /* count number of allocated ones */
#endif
struct def *ill_df;
struct def *
MkDef(id, scope, kind)
struct idf *id;
register struct scope *scope;
{
/* Create a new definition structure in scope "scope", with
id "id" and kind "kind".
*/
register struct def *df;
df = new_def();
clear((char *) df, sizeof (*df));
df->df_idf = id;
df->df_scope = scope;
df->df_kind = kind;
df->next = id->id_def;
id->id_def = df;
/* enter the definition in the list of definitions in this scope
*/
df->df_nextinscope = scope->sc_def;
scope->sc_def = df;
return df;
}
InitDef()
{
/* Initialize this module. Easy, the only thing to be initialized
is "ill_df".
*/
struct idf *gen_anon_idf();
ill_df = MkDef(gen_anon_idf(), CurrentScope, D_ERROR);
}
struct def *
define(id, scope, kind)
register struct idf *id;
register struct scope *scope;
{
/* Declare an identifier in a scope, but first check if it
already has been defined. If so, error message.
*/
register struct def *df;
df = lookup(id, scope);
if ( /* Already in this scope */
df
|| /* A closed scope, and id defined in the pervasive scope */
(
scopeclosed(scope)
&&
(df = lookup(id, PervasiveScope)))
) {
switch(df->df_kind) {
case D_HIDDEN:
/* An opaque type. We may now have found the
definition of this type.
*/
if (kind == D_TYPE && !DefinitionModule) {
df->df_kind = D_TYPE;
return df;
}
break;
case D_FORWMODULE:
/* A forward reference to a module. We may have found
another one, or we may have found the definition
for this module.
*/
if (kind == D_FORWMODULE) {
return df;
}
if (kind == D_MODULE) {
FreeNode(df->for_node);
df->mod_vis = df->for_vis;
df->df_kind = kind;
DefInFront(df);
return df;
}
break;
case D_FORWARD:
/* A forward reference, for which we may now have
found a definition.
*/
if (kind != D_FORWARD) {
FreeNode(df->for_node);
}
/* Fall through */
case D_ERROR:
/* A definition generated by the compiler, because
it found an error. Maybe, the user gives a
definition after all.
*/
df->df_kind = kind;
return df;
}
if (kind != D_ERROR) {
/* Avoid spurious error messages
*/
error("identifier \"%s\" already declared", id->id_text);
}
return df;
}
return MkDef(id, scope, kind);
}
RemoveImports(pdf)
struct def **pdf;
{
/* Remove all imports from a definition module. This is
neccesary because the implementation module might import
them again.
*/
register struct def *df = *pdf;
while (df) {
if (df->df_kind == D_IMPORT) {
RemoveFromIdList(df);
*pdf = df->df_nextinscope;
free_def(df);
}
else {
pdf = &(df->df_nextinscope);
}
df = *pdf;
}
}
RemoveFromIdList(df)
struct def *df;
{
/* Remove definition "df" from the definition list
*/
register struct idf *id = df->df_idf;
register struct def *df1;
if (id->id_def == df) id->id_def = df->next;
else {
df1 = id->id_def;
while (df1->next != df) {
assert(df1->next != 0);
df1 = df1->next;
}
df1->next = df->next;
}
}
struct def *
DeclProc(type)
{
/* A procedure is declared, either in a definition or a program
module. Create a def structure for it (if neccessary).
Also create a name for it.
*/
register struct def *df;
extern char *sprint();
static int nmcount;
char buf[256];
assert(type & (D_PROCEDURE | D_PROCHEAD));
if (type == D_PROCHEAD) {
/* In a definition module
*/
df = define(dot.TOK_IDF, CurrentScope, type);
df->for_node = MkLeaf(Name, &dot);
sprint(buf,"%s_%s",CurrentScope->sc_name,df->df_idf->id_text);
df->for_name = Salloc(buf, (unsigned) (strlen(buf)+1));
if (CurrVis == Defined->mod_vis) C_exp(df->for_name);
open_scope(OPENSCOPE);
}
else {
df = lookup(dot.TOK_IDF, CurrentScope);
if (df && df->df_kind == D_PROCHEAD) {
/* C_exp already generated when we saw the definition
in the definition module
*/
df->df_kind = D_PROCEDURE;
open_scope(OPENSCOPE);
CurrentScope->sc_name = df->for_name;
df->prc_vis = CurrVis;
DefInFront(df);
}
else {
df = define(dot.TOK_IDF, CurrentScope, type);
open_scope(OPENSCOPE);
df->prc_vis = CurrVis;
sprint(buf,"_%d_%s",++nmcount,df->df_idf->id_text);
CurrentScope->sc_name =
Salloc(buf, (unsigned)(strlen(buf)+1));
C_inp(buf);
}
}
return df;
}
AddModule(id)
struct idf *id;
{
/* Add the name of a module to the Module list. This list is
maintained to create the initialization routine of the
program/implementation module currently defined.
*/
static struct node *nd_end; /* to remember end of list */
register struct node *n;
extern struct node *Modules;
n = MkLeaf(Name, &dot);
n->nd_IDF = id;
n->nd_symb = IDENT;
if (nd_end) nd_end->next = n;
else Modules = n;
nd_end = n;
}
DefInFront(df)
register struct def *df;
{
/* Put definition "df" in front of the list of definitions
in its scope.
This is neccessary because in some cases the order in this
list is important.
*/
register struct def *df1 = df->df_scope->sc_def;
if (df1 != df) {
/* Definition "df" is not in front of the list
*/
while (df1 && df1->df_nextinscope != df) {
/* Find definition "df"
*/
df1 = df1->df_nextinscope;
}
if (df1) {
/* It already was in the list. Remove it
*/
df1->df_nextinscope = df->df_nextinscope;
}
/* Now put it in front
*/
df->df_nextinscope = df->df_scope->sc_def;
df->df_scope->sc_def = df;
}
}
struct def *
DefineLocalModule(id)
struct idf *id;
{
/* Create a definition for a local module. Also give it
a name to be used for code generation.
*/
register struct def *df = define(id, CurrentScope, D_MODULE);
register struct type *tp;
register struct scope *sc;
static int modulecount = 0;
char buf[256];
extern char *sprint();
extern int proclevel;
sprint(buf, "_%d%s", ++modulecount, id->id_text);
if (!df->mod_vis) {
/* We never saw the name of this module before. Create a
scope for it.
*/
open_scope(CLOSEDSCOPE);
df->mod_vis = CurrVis;
}
CurrVis = df->mod_vis;
sc = CurrentScope;
sc->sc_level = proclevel;
sc->sc_definedby = df;
sc->sc_name = Salloc(buf, (unsigned) (strlen(buf) + 1));
/* Create a type for it
*/
df->df_type = tp = standard_type(T_RECORD, 0, (arith) 0);
tp->rec_scope = sc;
/* Generate code that indicates that the initialization procedure
for this module is local.
*/
C_inp(buf);
return df;
}
#ifdef DEBUG
PrDef(df)
register struct def *df;
{
print("n: %s, k: %d\n", df->df_idf->id_text, df->df_kind);
}
#endif DEBUG