newer version, safety commit

lang/m2/comp/LLlex.c

@@ -4,6 +4,7 @@ static char *RcsId = "$Header$";
 
 #include	<alloc.h>
 #include	<em_arith.h>
+#include	<assert.h>
 #include	"input.h"
 #include	"f_info.h"
 #include	"Lpars.h"
@@ -179,7 +180,7 @@ again:
 			return tk->tk_symb = ch;
 
 		default :
-			crash("bad STCOMP");
+			assert(0);
 		}
 
 	case STIDF:
@@ -373,7 +374,7 @@ Sdec:
 
 	case STCHAR:
 	default:
-		crash("bad character class %d", class(ch));
+		assert(0);
 	}
 	/*NOTREACHED*/
 }

lang/m2/comp/declar.g

@@ -130,7 +130,12 @@ TypeDeclaration
 }:
 	IDENT		{ df = define(dot.TOK_IDF, CurrentScope, D_TYPE); }
 	'=' type(&tp)
-			{ df->df_type = tp; }
+			{ df->df_type = tp;
+			  if ((df->df_flags&D_EXPORTED) &&
+			      tp->tp_fund == ENUMERATION) {
+				exprt_literals(tp->enm_enums, enclosing(currscope));
+			  }
+			}
 ;
 
 type(struct type **ptp;):
@@ -338,7 +343,7 @@ PointerType(struct type **ptp;)
 				  }
 				  else	tp = df->df_type;
 				}
-	| %if (df = lookfor(dot.TOK_IDF, 0), df->df_kind == D_MODULE)
+	| %if (df = lookfor(dot.TOK_IDF, currscope, 0), df->df_kind == D_MODULE)
 		type(&tp)
 	|
 		IDENT

lang/m2/comp/def.H

@@ -38,8 +38,8 @@ struct field {
 };
 
 struct import {
-	int im_scopenr;		/* Scope number from which imported */
-#define imp_scopenr	df_value.df_import.im_scopenr
+	struct def *im_def;	/* Scope number from which imported */
+#define imp_def		df_value.df_import.im_def
 };
 
 struct def	{		/* list of definitions for a name */

lang/m2/comp/def.c

@@ -8,6 +8,7 @@ static char *RcsId = "$Header$";
 #include	<assert.h>
 #include	"Lpars.h"
 #include	"def.h"
+#include	"type.h"
 #include	"idf.h"
 #include	"misc.h"
 #include	"main.h"
@@ -60,7 +61,9 @@ define(id, scope, kind)
 			df->df_kind = kind;
 			return df;
 		}
-		error("identifier \"%s\" already declared", id->id_text);
+		if (kind != D_ERROR) {
+			error("identifier \"%s\" already declared", id->id_text);
+		}
 		return df;
 	}
 	df = new_def();
@@ -98,12 +101,9 @@ lookup(id, scope)
 	while (df) {
 		if (df->df_scope == scope) {
 			if (df->df_kind == D_IMPORT) {
-				df = lookup(id, df->imp_scopenr);
+				df = df->imp_def;
 				assert(df != 0);
 				return df;
-				/* ??? But this does damage to the self-
-				   organizing character of the list
-				*/
 			}
 			if (df1) {
 				df1->next = df->next;
@@ -118,14 +118,14 @@ lookup(id, scope)
 	return 0;
 }
 
-/*	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".
-*/
 Export(ids, qualified)
 	register struct id_list *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;
 
 	while (ids) {
@@ -142,53 +142,88 @@ Export(ids, qualified)
 	}
 }
 
-/*	"ids" is a list of imported identifiers.
-	If "id" is a null-pointer, the identifiers are imported from the
-	enclosing scope. Otherwise they are imported from the module
-	indicated by "id", ehich 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 "id" is a null pointer, the "ids" identifiers
-	are all module identifiers. Their Definition Modules must be read.
-	Otherwise "id" is a module identifier whose Definition Module must
-	be read. "ids" then represents a list of identifiers defined in
-	this module.
-*/
 Import(ids, id, local)
 	register struct id_list *ids;
 	struct idf *id;
 {
+	/*	"ids" is a list of imported identifiers.
+		If "id" is a null-pointer, the identifiers are imported from the
+		enclosing scope. Otherwise they are imported from the module
+		indicated by "id", ehich 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 "id" is a null pointer, the "ids" identifiers
+		are all module identifiers. Their Definition Modules must be
+		read.  Otherwise "id" 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;
 	int scope;
 	int kind;
+	int imp_kind;
+#define FROM_MODULE	0
+#define FROM_ENCLOSING	1
 	struct def *lookfor();
 
 	if (local) {
 		kind = D_IMPORT;
-		if (!id) scope = enclosing(currscope)->sc_scope;
+		scope = enclosing(currscope)->sc_scope;
+		if (!id) imp_kind = FROM_ENCLOSING;
 		else {
-			df = lookfor(id, 1);
+			imp_kind = FROM_MODULE;
+			df = lookfor(id, enclosing(currscope), 1);
 			if (df->df_kind != D_MODULE) {
+				/* enter all "ids" with type D_ERROR */
+				kind = D_ERROR;
 				if (df->df_kind != D_ERROR) {
 error("identifier \"%s\" does not represent a module", id->id_text);
 				}
-				/* enter all "ids" with type D_ERROR */
-				kind = D_ERROR;
-				scope = enclosing(currscope)->sc_scope;
 			}
 			else	scope = df->mod_scope;
 		}
 		while (ids) {
-			df = lookup(ids->id_ptr, scope);
-			if (!df) {
-				error("identifier \"%s\" not declared",
-				      ids->id_ptr->id_text);
+			if (imp_kind == FROM_MODULE) {
+				if (!(df = lookup(ids->id_ptr, scope))) {
+error("identifier \"%s\" not declared in qualifying module",
+ids->id_ptr->id_text);
+					df = ill_df;
+				}
+				else 
+				if (!(df->df_flags&(D_EXPORTED|D_QEXPORTED))) {
+error("identifier \"%s\" not exported from qualifying module",
+ids->id_ptr->id_text);
+				}
+			}
+			else {
+				df = lookfor(ids->id_ptr, enclosing(currscope), 0);
+				if (df->df_kind == D_ERROR) {
+error("identifier \"%s\" not visible in enclosing scope",
+ids->id_ptr->id_text);
+				}
+			}
+			define(ids->id_ptr, CurrentScope, kind)->imp_def = df;
+			if (df->df_kind == D_TYPE &&
+			    df->df_type->tp_fund == ENUMERATION) {
+				/* Also import all enumeration literals */
+				exprt_literals(df->df_type->enm_enums, currscope);
 			}
-			df = define(ids->id_ptr, CurrentScope, D_IMPORT);
-			df->imp_scopenr = scope;
 			ids = ids->next;
 		}
 		return;
 	}
 	/* ???? */
 }
+
+exprt_literals(df, toscope)
+	register struct def *df;
+	register struct scope *toscope;
+{
+	/*	A list of enumeration literals is exported. This is implemented
+		as an import from the scope "toscope".
+	*/
+	while (df) {
+		define(df->df_idf, toscope->sc_scope, D_IMPORT)->imp_def = df;
+		df = df->enm_next;
+	}
+}

lang/m2/comp/enter.c

@@ -60,16 +60,18 @@ EnterIdList(idlist, kind, flags, type, scope)
 	}
 }
 
-/*	Look for an identifier in the current visibility range.
-	If it is not defined, give an error message, and
-	create a dummy definition.
-*/
 struct def *
-lookfor(id, give_error)
+lookfor(id, scope, give_error)
 	struct idf *id;
+	struct scope *scope;
 {
-	register struct scope *sc = currscope;
+	/*	Look for an identifier in the visibility range started by
+		"scope".
+		If it is not defined, give an error message, and
+		create a dummy definition.
+	*/
 	struct def *df;
+	register struct scope *sc = scope;
 
 	while (sc) {
 		df = lookup(id, sc->sc_scope);
@@ -77,5 +79,5 @@ lookfor(id, give_error)
 		sc = nextvisible(sc);
 	}
 	if (give_error) error("Identifier \"%s\" not declared", id->id_text);
-	return define(id, CurrentScope, D_ERROR);
+	return define(id, scope->sc_scope, D_ERROR);
 }

lang/m2/comp/expression.g

@@ -21,11 +21,12 @@ number:
 qualident(int types; struct def **pdf; char *str;)
 {
 	int scope;
+	int  module;
 	register struct def *df;
 	struct def *lookfor();
 } :
 	IDENT		{ if (types) {
-				*pdf = df = lookfor(dot.TOK_IDF, 1);
+				*pdf = df = lookfor(dot.TOK_IDF, currscope, 1);
 				if (df->df_kind == D_ERROR) types = 0;
 			  }
 			}
@@ -38,6 +39,7 @@ qualident(int types; struct def **pdf; char *str;)
 		/* selector */
 		'.' IDENT
 			{ if (types) {
+				module = (df->df_kind == D_MODULE);
 				df = lookup(dot.TOK_IDF, scope);
 				if (!df) {
 					error("identifier \"%s\" not declared",
@@ -45,6 +47,11 @@ qualident(int types; struct def **pdf; char *str;)
 					types = 0;
 					df = ill_df;
 				}
+				else
+				if (module &&
+				    !(df->df_flags&(D_EXPORTED|D_QEXPORTED))) {
+					error("identifier \"%s\" not exported from qualifying module", dot.TOK_IDF->id_text);
+				}
 			  }
 			}
 	]*

lang/m2/comp/program.g

@@ -35,9 +35,13 @@ static  char *RcsId = "$Header$";
 ModuleDeclaration
 {
 	struct idf *id;
+	struct def *df;
 } :
-	MODULE IDENT		{ open_scope(CLOSEDSCOPE, 0);
+	MODULE IDENT		{
 				  id = dot.TOK_IDF;
+				  df = define(id, CurrentScope, D_MODULE);
+				  open_scope(CLOSEDSCOPE, 0);
+				  df->mod_scope = CurrentScope;
 				}
 	priority? ';'
 	import(1)*

lang/m2/comp/scope.C

@@ -118,7 +118,7 @@ rem_forwards(fo)
 	savetok = dot;
 	while (f = fo) {
 		dot = f->fo_tok;
-		df = lookfor(dot.TOK_IDF, 1);
+		df = lookfor(dot.TOK_IDF, currscope, 1);
 		if (!(df->df_kind & (D_TYPE | D_HTYPE | D_ERROR))) {
 			error("identifier \"%s\" not a type", df->df_idf->id_text);
 		}