400 lines
8.3 KiB
C
400 lines
8.3 KiB
C
/*
|
|
* (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
|
|
* See the copyright notice in the ACK home directory, in the file "Copyright".
|
|
*
|
|
* Author: Ceriel J.H. Jacobs
|
|
*/
|
|
|
|
/* D E F I N I T I O N M E C H A N I S M */
|
|
|
|
/* $Header$ */
|
|
|
|
#include "debug.h"
|
|
|
|
#include <alloc.h>
|
|
#include <em_arith.h>
|
|
#include <em_label.h>
|
|
#include <em_code.h>
|
|
#include <assert.h>
|
|
|
|
#include "LLlex.h"
|
|
#include "main.h"
|
|
#include "def.h"
|
|
#include "type.h"
|
|
#include "idf.h"
|
|
#include "scope.h"
|
|
#include "node.h"
|
|
#include "Lpars.h"
|
|
#include "warning.h"
|
|
|
|
STATIC
|
|
internal(c)
|
|
register char *c;
|
|
{
|
|
if (options['x']) {
|
|
C_exp(c);
|
|
}
|
|
else C_inp(c);
|
|
}
|
|
|
|
STATIC
|
|
DefInFront(df)
|
|
register t_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 t_def *df1 = df->df_scope->sc_def;
|
|
|
|
if (df1 != df) {
|
|
/* Definition "df" is not in front of the list
|
|
*/
|
|
while (df1) {
|
|
/* Find definition "df"
|
|
*/
|
|
if (df1->df_nextinscope == df) {
|
|
/* It already was in the list. Remove it
|
|
*/
|
|
df1->df_nextinscope = df->df_nextinscope;
|
|
break;
|
|
}
|
|
df1 = df1->df_nextinscope;
|
|
}
|
|
|
|
/* Now put it in front
|
|
*/
|
|
df->df_nextinscope = df->df_scope->sc_def;
|
|
df->df_scope->sc_def = df;
|
|
}
|
|
}
|
|
|
|
t_def *
|
|
MkDef(id, scope, kind)
|
|
register t_idf *id;
|
|
register t_scope *scope;
|
|
{
|
|
/* Create a new definition structure in scope "scope", with
|
|
id "id" and kind "kind".
|
|
*/
|
|
register t_def *df;
|
|
|
|
df = new_def();
|
|
df->df_idf = id;
|
|
df->df_scope = scope;
|
|
df->df_kind = kind;
|
|
df->df_next = id->id_def;
|
|
id->id_def = df;
|
|
if (kind == D_ERROR || kind == D_FORWARD) df->df_type = error_type;
|
|
if (kind & (D_TYPE|D_PROCEDURE|D_CONST)) {
|
|
df->df_flags = D_DEFINED;
|
|
}
|
|
|
|
/* enter the definition in the list of definitions in this scope
|
|
*/
|
|
df->df_nextinscope = scope->sc_def;
|
|
scope->sc_def = df;
|
|
return df;
|
|
}
|
|
|
|
t_def *
|
|
define(id, scope, kind)
|
|
register t_idf *id;
|
|
register t_scope *scope;
|
|
int kind;
|
|
{
|
|
/* Declare an identifier in a scope, but first check if it
|
|
already has been defined.
|
|
If so, then check for the cases in which this is legal,
|
|
and otherwise give an error message.
|
|
*/
|
|
register t_def *df;
|
|
|
|
df = lookup(id, scope, D_IMPORT, 0);
|
|
if ( /* Already in this scope */
|
|
df
|
|
) {
|
|
switch(df->df_kind) {
|
|
case D_INUSE:
|
|
if (kind != D_INUSE) {
|
|
error("identifier \"%s\" already used; may not be redefined in this scope", df->df_idf->id_text);
|
|
}
|
|
return df;
|
|
|
|
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_TYPE:
|
|
if (kind == D_FORWTYPE) return df;
|
|
break;
|
|
case D_FORWTYPE:
|
|
if (kind == D_FORWTYPE) return df;
|
|
if (kind == D_TYPE) {
|
|
df->df_kind = D_FTYPE;
|
|
}
|
|
else {
|
|
error("identifier \"%s\" must be a type",
|
|
id->id_text);
|
|
}
|
|
return df;
|
|
|
|
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);
|
|
}
|
|
|
|
end_definition_list(pdf)
|
|
register t_def **pdf;
|
|
{
|
|
/* Remove all imports from a definition module. This is
|
|
neccesary because the implementation module might import
|
|
them again.
|
|
Also, mark all other definitions "QUALIFIED EXPORT".
|
|
*/
|
|
register t_def *df;
|
|
|
|
while (df = *pdf) {
|
|
if (df->df_kind & D_IMPORTED) {
|
|
if (! (df->df_flags & D_USED)) {
|
|
warning(W_ORDINARY, "identifier \"%s\" imported but not used", df->df_idf->id_text);
|
|
}
|
|
RemoveFromIdList(df);
|
|
*pdf = df->df_nextinscope;
|
|
free_def(df);
|
|
}
|
|
else {
|
|
df->df_flags |= D_QEXPORTED;
|
|
pdf = &(df->df_nextinscope);
|
|
}
|
|
}
|
|
}
|
|
|
|
RemoveFromIdList(df)
|
|
register t_def *df;
|
|
{
|
|
/* Remove definition "df" from the definition list
|
|
*/
|
|
register t_idf *id = df->df_idf;
|
|
register t_def *df1;
|
|
|
|
if ((df1 = id->id_def) == df) id->id_def = df->df_next;
|
|
else {
|
|
while (df1->df_next != df) {
|
|
assert(df1->df_next != 0);
|
|
df1 = df1->df_next;
|
|
}
|
|
df1->df_next = df->df_next;
|
|
}
|
|
}
|
|
|
|
t_def *
|
|
DeclProc(type, id)
|
|
register t_idf *id;
|
|
{
|
|
/* 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 t_def *df;
|
|
register t_scope *scope;
|
|
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(id, CurrentScope, type);
|
|
df->for_node = dot2leaf(Name);
|
|
df->df_flags |= D_USED | D_DEFINED;
|
|
if (CurrentScope->sc_definedby->df_flags & D_FOREIGN) {
|
|
df->for_name = id->id_text;
|
|
}
|
|
else {
|
|
sprint(buf,"%s_%s",CurrentScope->sc_name,id->id_text);
|
|
df->for_name = Salloc(buf, (unsigned) (strlen(buf)+1));
|
|
}
|
|
if (CurrVis == Defined->mod_vis) {
|
|
/* The current module will define this routine.
|
|
make sure the name is exported.
|
|
*/
|
|
C_exp(df->for_name);
|
|
}
|
|
}
|
|
else {
|
|
char *name;
|
|
|
|
df = lookup(id, CurrentScope, D_IMPORTED, 0);
|
|
if (df && df->df_kind == D_PROCHEAD) {
|
|
/* C_exp already generated when we saw the definition
|
|
in the definition module
|
|
*/
|
|
name = df->for_name;
|
|
DefInFront(df);
|
|
}
|
|
else {
|
|
df = define(id, CurrentScope, type);
|
|
sprint(buf,"_%d_%s",++nmcount,id->id_text);
|
|
name = Salloc(buf, (unsigned)(strlen(buf)+1));
|
|
internal(buf);
|
|
df->df_flags |= D_DEFINED;
|
|
}
|
|
open_scope(OPENSCOPE);
|
|
scope = CurrentScope;
|
|
scope->sc_name = name;
|
|
scope->sc_definedby = df;
|
|
}
|
|
df->prc_vis = CurrVis;
|
|
|
|
return df;
|
|
}
|
|
|
|
EndProc(df, id)
|
|
register t_def *df;
|
|
t_idf *id;
|
|
{
|
|
/* The end of a procedure declaration.
|
|
Check that the closing identifier matches the name of the
|
|
procedure, close the scope, and check that a function
|
|
procedure has at least one RETURN statement.
|
|
*/
|
|
extern int return_occurred;
|
|
|
|
match_id(id, 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);
|
|
}
|
|
}
|
|
|
|
t_def *
|
|
DefineLocalModule(id)
|
|
t_idf *id;
|
|
{
|
|
/* Create a definition for a local module. Also give it
|
|
a name to be used for code generation.
|
|
*/
|
|
register t_def *df = define(id, CurrentScope, D_MODULE);
|
|
register t_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 = standard_type(T_RECORD, 1, (arith) 0);
|
|
df->df_type->rec_scope = sc;
|
|
|
|
/* Generate code that indicates that the initialization procedure
|
|
for this module is local.
|
|
*/
|
|
internal(buf);
|
|
return df;
|
|
}
|
|
|
|
CheckWithDef(df, tp)
|
|
register t_def *df;
|
|
t_type *tp;
|
|
{
|
|
/* Check the header of a procedure declaration against a
|
|
possible earlier definition in the definition module.
|
|
*/
|
|
|
|
if (df->df_kind == D_PROCHEAD &&
|
|
df->df_type &&
|
|
df->df_type != error_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_kind = D_PROCEDURE;
|
|
}
|
|
df->df_type = tp;
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
PrDef(df)
|
|
register t_def *df;
|
|
{
|
|
print("n: %s, k: %d\n", df->df_idf->id_text, df->df_kind);
|
|
}
|
|
#endif DEBUG
|