Initial revision

lang/pc/comp/scope.c

@@ -0,0 +1,111 @@
+/* S C O P E   M E C H A N I S M */
+
+#include	"debug.h"
+
+#include	<alloc.h>
+#include	<assert.h>
+#include	<em_arith.h>
+#include	<em_label.h>
+
+#include	"LLlex.h"
+#include	"def.h"
+#include	"idf.h"
+#include	"misc.h"
+#include	"node.h"
+#include	"scope.h"
+#include	"type.h"
+
+struct scope *GlobalScope, *PervasiveScope, *BlockScope;
+struct scopelist *CurrVis;
+extern int proclevel;			/* declared in declar.g */
+
+InitScope()
+{
+	register struct scope *sc = new_scope();
+	register struct scopelist *ls = new_scopelist();
+
+	sc->sc_def = 0;
+	sc->sc_level = proclevel;
+	PervasiveScope = sc;
+	ls->next = 0;
+	ls->sc_scope = PervasiveScope;
+	CurrVis = ls;
+}
+
+open_scope()
+{
+	register struct scope *sc = new_scope();
+	register struct scopelist *ls = new_scopelist();
+
+	sc->sc_level = proclevel;
+	ls->sc_scope = sc;
+	ls->next = CurrVis;
+	CurrVis = ls;
+}
+
+close_scope()
+{
+	/* When this procedure is called, the next visible scope is equal to
+	   the statically enclosing scope
+	*/
+
+	assert(CurrentScope != 0);
+	CurrVis = CurrVis->next;
+}
+
+Forward(nd, tp)
+	register struct node *nd;
+	register struct type *tp;
+{
+	/* Enter a forward reference into the current scope. This is
+	 * used in pointertypes.
+	 */
+	register struct def *df = define(nd->nd_IDF, CurrentScope, D_FORWTYPE);
+	register struct forwtype *fw_type = new_forwtype();
+
+	fw_type->f_next = df->df_fortype;
+	df->df_fortype = fw_type;
+
+	fw_type->f_node = nd;
+	fw_type->f_type = tp;
+}
+
+STATIC
+chk_prog_params()
+{
+	/* the program parameters must be global variables of some file type */
+	register struct def *df = CurrentScope->sc_def;
+
+	while( df )	{
+	    if( df->df_kind & D_PARAMETER )	{
+		if( !is_anon_idf(df->df_idf) )	{
+		    if( df->df_type == error_type )
+		     error("program parameter \"%s\" must be a global variable",
+							df->df_idf->id_text);
+		    else if( df->df_type->tp_fund != T_FILE )
+			error("program parameter \"%s\" must have a file type",
+							df->df_idf->id_text);
+
+		    df->df_kind = D_VARIABLE;
+		}
+		else df->df_kind = D_ERROR;
+	    }
+	    df = df->df_nextinscope;
+	}
+}
+
+STATIC
+chk_directives()
+{
+	/* check if all forward declarations are defined */
+	register struct def *df = CurrentScope->sc_def;
+
+	while( df )	{
+		if( df->df_kind == D_FWPROCEDURE )
+		     error("procedure \"%s\" not defined", df->df_idf->id_text);
+		else if( df->df_kind == D_FWFUNCTION )
+		      error("function \"%s\" not defined", df->df_idf->id_text);
+
+		df = df->df_nextinscope;
+	}
+}