449 lines
10 KiB
C
449 lines
10 KiB
C
/* D E F I N I T I O N M E C H A N I S M */
|
|
|
|
static char *RcsId = "$Header$";
|
|
|
|
#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 "debug.h"
|
|
|
|
struct def *h_def; /* Pointer to free list of def structures */
|
|
|
|
static struct def illegal_def =
|
|
{0, 0, 0, 0, D_ERROR};
|
|
|
|
struct def *ill_df = &illegal_def;
|
|
|
|
struct def *
|
|
MkDef(id, scope, kind)
|
|
struct idf *id;
|
|
struct scope *scope;
|
|
{
|
|
/* Create a new definition structure in scope "scope", with
|
|
id "id" and kind "kind".
|
|
*/
|
|
register struct def *df;
|
|
|
|
df = new_def();
|
|
df->df_flags = 0;
|
|
df->df_idf = id;
|
|
df->df_scope = scope;
|
|
df->df_kind = kind;
|
|
df->df_type = 0;
|
|
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;
|
|
}
|
|
|
|
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;
|
|
|
|
DO_DEBUG(5, debug("Defining identifier \"%s\", kind = %d",
|
|
id->id_text, kind));
|
|
df = lookup(id, scope);
|
|
if ( /* Already in this scope */
|
|
df
|
|
|| /* A closed scope, and id defined in the pervasive scope */
|
|
( CurrentScope == scope
|
|
&&
|
|
scopeclosed(scope)
|
|
&&
|
|
(df = lookup(id, PervasiveScope)))
|
|
) {
|
|
switch(df->df_kind) {
|
|
case D_HIDDEN:
|
|
if (kind == D_TYPE && !DefinitionModule) {
|
|
df->df_kind = D_HTYPE;
|
|
return df;
|
|
}
|
|
break;
|
|
case D_FORWMODULE:
|
|
if (kind == D_FORWMODULE) {
|
|
return df;
|
|
}
|
|
if (kind == D_MODULE) {
|
|
FreeNode(df->for_node);
|
|
df->mod_scope = df->for_scope;
|
|
df->df_kind = kind;
|
|
return df;
|
|
}
|
|
break;
|
|
case D_FORWARD:
|
|
if (kind != D_FORWARD) {
|
|
FreeNode(df->for_node);
|
|
}
|
|
/* Fall Through */
|
|
case D_ERROR:
|
|
df->df_kind = kind;
|
|
return df;
|
|
}
|
|
if (kind != D_ERROR) {
|
|
error("identifier \"%s\" already declared", id->id_text);
|
|
}
|
|
return df;
|
|
}
|
|
return MkDef(id, scope, kind);
|
|
}
|
|
|
|
struct def *
|
|
lookup(id, scope)
|
|
register struct idf *id;
|
|
struct scope *scope;
|
|
{
|
|
/* Look up a definition of an identifier in scope "scope".
|
|
Make the "def" list self-organizing.
|
|
Return a pointer to its "def" structure if it exists,
|
|
otherwise return 0.
|
|
*/
|
|
register struct def *df, *df1;
|
|
struct def *retval;
|
|
|
|
df1 = 0;
|
|
df = id->id_def;
|
|
while (df) {
|
|
if (df->df_scope == scope) {
|
|
retval = df;
|
|
if (df->df_kind == D_IMPORT) {
|
|
retval = df->imp_def;
|
|
assert(retval != 0);
|
|
}
|
|
|
|
if (df1) {
|
|
df1->next = df->next;
|
|
df->next = id->id_def;
|
|
id->id_def = df;
|
|
}
|
|
return retval;
|
|
}
|
|
df1 = df;
|
|
df = df->next;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
Export(ids, qualified)
|
|
register struct node *ids;
|
|
{
|
|
/* From the current scope, the list of identifiers "ids" is
|
|
exported. Note this fact. If the export is not qualified, make
|
|
all the "ids" visible in the enclosing scope by defining them
|
|
in this scope as "imported".
|
|
*/
|
|
register struct def *df, *df1;
|
|
struct node *nd = ids;
|
|
|
|
while (ids) {
|
|
df = lookup(ids->nd_IDF, CurrentScope);
|
|
if (df && (df->df_flags & (D_EXPORTED|D_QEXPORTED))) {
|
|
node_error(ids, "Identifier \"%s\" occurs more than once in export list",
|
|
df->df_idf->id_text);
|
|
}
|
|
else if (!df) {
|
|
df = define(ids->nd_IDF, CurrentScope, D_FORWARD);
|
|
df->for_node = MkNode(Name,NULLNODE,NULLNODE,
|
|
&(ids->nd_token));
|
|
}
|
|
if (qualified) {
|
|
df->df_flags |= D_QEXPORTED;
|
|
}
|
|
else {
|
|
df->df_flags |= D_EXPORTED;
|
|
df1 = lookup(ids->nd_IDF, enclosing(CurrentScope));
|
|
if (! df1 || !(df1->df_kind & (D_PROCHEAD|D_HIDDEN))) {
|
|
df1 = define(ids->nd_IDF,
|
|
enclosing(CurrentScope),
|
|
D_IMPORT);
|
|
}
|
|
else {
|
|
/* A hidden type or a procedure of which only
|
|
the head is seen. Apparently, they are
|
|
exported from a local module!
|
|
*/
|
|
df->df_kind = df1->df_kind;
|
|
df->df_value.df_forward = df1->df_value.df_forward;
|
|
df1->df_kind = D_IMPORT;
|
|
}
|
|
df1->imp_def = df;
|
|
}
|
|
ids = ids->next;
|
|
}
|
|
FreeNode(nd);
|
|
}
|
|
|
|
static struct scope *
|
|
ForwModule(df, idn)
|
|
register struct def *df;
|
|
struct node *idn;
|
|
{
|
|
/* An import is done from a not yet defined module "idn".
|
|
Create a declaration and a scope for this module.
|
|
*/
|
|
struct scope *scope;
|
|
|
|
df->df_scope = enclosing(CurrentScope);
|
|
df->df_kind = D_FORWMODULE;
|
|
open_scope(CLOSEDSCOPE);
|
|
scope = CurrentScope; /* The new scope, but watch out, it's "next"
|
|
field is not set right. It must indicate the
|
|
enclosing scope, but this must be done AFTER
|
|
closing this one
|
|
*/
|
|
df->for_scope = scope;
|
|
df->for_node = MkNode(Name, NULLNODE, NULLNODE, &(idn->nd_token));
|
|
close_scope(0);
|
|
scope->next = df->df_scope;
|
|
/* Here ! */
|
|
return scope;
|
|
}
|
|
|
|
static struct def *
|
|
ForwDef(ids, scope)
|
|
register struct node *ids;
|
|
struct scope *scope;
|
|
{
|
|
/* Enter a forward definition of "ids" in scope "scope",
|
|
if it is not already defined.
|
|
*/
|
|
register struct def *df;
|
|
|
|
if (!(df = lookup(ids->nd_IDF, scope))) {
|
|
df = define(ids->nd_IDF, scope, D_FORWARD);
|
|
df->for_node = MkNode(Name,NULLNODE,NULLNODE,&(ids->nd_token));
|
|
}
|
|
return df;
|
|
}
|
|
|
|
Import(ids, idn, local)
|
|
register struct node *ids;
|
|
struct node *idn;
|
|
{
|
|
/* "ids" is a list of imported identifiers.
|
|
If "idn" is a null-pointer, the identifiers are imported from
|
|
the enclosing scope. Otherwise they are imported from the module
|
|
indicated by "idn", which must be visible in the enclosing
|
|
scope. An exception must be made for imports of the
|
|
Compilation Unit.
|
|
This case is indicated by the value 0 of the flag "local".
|
|
In this case, if "idn" is a null pointer, the "ids" identifiers
|
|
are all module identifiers. Their Definition Modules must be
|
|
read. Otherwise "idn" is a module identifier whose Definition
|
|
Module must be read. "ids" then represents a list of
|
|
identifiers defined in this module.
|
|
*/
|
|
register struct def *df;
|
|
struct scope *scope = enclosing(CurrentScope);
|
|
int kind = D_IMPORT;
|
|
int forwflag = 0;
|
|
#define FROM_MODULE 0
|
|
#define FROM_ENCLOSING 1
|
|
int imp_kind = FROM_ENCLOSING;
|
|
struct def *lookfor(), *GetDefinitionModule();
|
|
|
|
if (idn) {
|
|
imp_kind = FROM_MODULE;
|
|
if (local) {
|
|
df = lookfor(idn, scope, 0);
|
|
switch(df->df_kind) {
|
|
case D_ERROR:
|
|
/* The module from which the import was done
|
|
is not yet declared. I'm not sure if I must
|
|
accept this, but for the time being I will.
|
|
???
|
|
*/
|
|
scope = ForwModule(df, idn);
|
|
forwflag = 1;
|
|
break;
|
|
case D_FORWMODULE:
|
|
scope = df->for_scope;
|
|
break;
|
|
case D_MODULE:
|
|
scope = df->mod_scope;
|
|
break;
|
|
default:
|
|
kind = D_ERROR;
|
|
node_error(idn, "identifier \"%s\" does not represent a module",
|
|
idn->nd_IDF->id_text);
|
|
break;
|
|
}
|
|
}
|
|
else scope = GetDefinitionModule(idn->nd_IDF)->mod_scope;
|
|
|
|
FreeNode(idn);
|
|
}
|
|
|
|
idn = ids;
|
|
while (ids) {
|
|
if (imp_kind == FROM_MODULE) {
|
|
if (forwflag) {
|
|
df = ForwDef(ids, scope);
|
|
}
|
|
else if (!(df = lookup(ids->nd_IDF, scope))) {
|
|
node_error(ids, "identifier \"%s\" not declared in qualifying module",
|
|
ids->nd_IDF->id_text);
|
|
df = ill_df;
|
|
}
|
|
else if (!(df->df_flags&(D_EXPORTED|D_QEXPORTED))) {
|
|
node_error(ids,"identifier \"%s\" not exported from qualifying module",
|
|
ids->nd_IDF->id_text);
|
|
}
|
|
}
|
|
else {
|
|
if (local) df = ForwDef(ids, scope);
|
|
else df = GetDefinitionModule(ids->nd_IDF);
|
|
}
|
|
|
|
DO_DEBUG(2, debug("importing \"%s\", kind %d", ids->nd_IDF->id_text,
|
|
df->df_kind));
|
|
define(ids->nd_IDF, CurrentScope, kind)->imp_def = df;
|
|
if (df->df_kind == D_TYPE &&
|
|
df->df_type->tp_fund == T_ENUMERATION) {
|
|
/* Also import all enumeration literals
|
|
*/
|
|
exprt_literals(df->df_type->enm_enums, CurrentScope);
|
|
}
|
|
ids = ids->next;
|
|
}
|
|
|
|
FreeNode(idn);
|
|
}
|
|
|
|
exprt_literals(df, toscope)
|
|
register struct def *df;
|
|
struct scope *toscope;
|
|
{
|
|
/* A list of enumeration literals is exported. This is implemented
|
|
as an import from the scope "toscope".
|
|
*/
|
|
DO_DEBUG(3, debug("enumeration import:"));
|
|
while (df) {
|
|
DO_DEBUG(3, debug(df->df_idf->id_text));
|
|
define(df->df_idf, toscope, D_IMPORT)->imp_def = df;
|
|
df = df->enm_next;
|
|
}
|
|
}
|
|
|
|
RemImports(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) {
|
|
RemFromId(df);
|
|
*pdf = df->df_nextinscope;
|
|
free_def(df);
|
|
}
|
|
else {
|
|
pdf = &(df->df_nextinscope);
|
|
}
|
|
df = *pdf;
|
|
}
|
|
}
|
|
|
|
RemFromId(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)
|
|
*/
|
|
register struct def *df;
|
|
extern char *sprint(), *Malloc(), *strcpy();
|
|
static int nmcount = 0;
|
|
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 = MkNode(Name, NULLNODE, NULLNODE, &dot);
|
|
sprint(buf,"%s_%s",CurrentScope->sc_name,df->df_idf->id_text);
|
|
df->for_name = Malloc((unsigned) (strlen(buf)+1));
|
|
strcpy(df->for_name, buf);
|
|
C_exp(df->for_name);
|
|
}
|
|
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_scope = CurrentScope;
|
|
}
|
|
else {
|
|
df = define(dot.TOK_IDF, CurrentScope, type);
|
|
if (CurrentScope != Defined->mod_scope) {
|
|
sprint(buf, "_%d_%s", ++nmcount,
|
|
df->df_idf->id_text);
|
|
}
|
|
else (sprint(buf, "%s_%s",df->df_scope->sc_name,
|
|
df->df_idf->id_text));
|
|
open_scope(OPENSCOPE);
|
|
df->prc_scope = CurrentScope;
|
|
CurrentScope->sc_name = Malloc((unsigned)(strlen(buf)+1));
|
|
strcpy(CurrentScope->sc_name, buf);
|
|
C_inp(buf);
|
|
}
|
|
df->prc_nbpar = 0;
|
|
}
|
|
|
|
return df;
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
PrDef(df)
|
|
register struct def *df;
|
|
{
|
|
debug("name: %s, kind: %d", df->df_idf->id_text, df->df_kind);
|
|
}
|
|
#endif DEBUG
|