newer version

1986-05-16 17:15:36 +00:00
parent 15896e422c
commit a4887558b8
15 changed files with 270 additions and 37 deletions
--- a/lang/m2/comp/desig.c
+++ b/lang/m2/comp/desig.c
@@ -0,0 +1,164 @@
+/* D E S I G N A T O R   E V A L U A T I O N */
+
+#ifndef NORCSID
+static char *RcsId = "$Header$";
+#endif
+
+/*	Code generation for designators.
+   	This file contains some routines that generate code common to address
+	as well as value computations, and leave a description in a "desig"
+	structure.  It also contains routines to load an address, load a value
+	or perform a store.
+*/
+
+#include	"debug.h"
+
+#include	<em_arith.h>
+#include	<em_label.h>
+#include	<assert.h>
+
+#include	"type.h"
+#include	"def.h"
+#include	"scope.h"
+#include	"desig.h"
+#include	"LLlex.h"
+#include	"node.h"
+
+CodeValue(ds, size)
+	register struct desig *ds;
+{
+	/*	Generate code to load the value of the designator described
+		in "ds"
+	*/
+
+	switch(ds->dsg_kind) {
+	case DSG_LOADED:
+		break;
+
+	case DSG_FIXED:
+		if (size == word_size) {
+			if (ds->dsg_name) {
+				C_loe_dnam(ds->dsg_name, ds->dsg_offset);
+			}
+			else	C_lol(ds->dsg_offset);
+			break;
+		}
+
+		if (size == dwird_size) {
+			if (ds->dsg_name) {
+				C_lde_dnam(ds->dsg_name, ds->dsg_offset);
+			}
+			else	C_ldl(ds->dsg_offset);
+			break;
+		}
+		/* Fall through */
+	case DSG_PLOADED:
+	case DSG_PFIXED:
+		CodeAddress(ds);
+		C_loi(size);
+		break;
+
+	case DSG_INDEXED:
+		C_lar(word_size);
+		break;
+
+	default:
+		assert(0);
+	}
+
+	ds->dsg_kind = DSG_LOADED;
+}
+
+CodeAddress(ds)
+	register struct desig *ds;
+{
+	/*	Generate code to load the address of the designator described
+	   	in "ds"
+	*/
+
+	switch(ds->dsg_kind) {
+	case DSG_PLOADED:
+		if (ds->dsg_offset) {
+			C_adp(ds->dsg_offset);
+		}
+		break;
+
+	case DSG_FIXED:
+		if (ds->dsg_name) {
+			C_lae_dnam(ds->dsg_name, ds->dsg_offset);
+			break;
+		}
+		C_lal(ds->dsg_offset);
+		break;
+		
+	case DSG_PFIXED:
+		ds->dsg_kind = DSG_FIXED;
+		CodeValue(ds, pointer_size);
+		break;
+
+	case DSG_INDEXED:
+		C_aar(word_size);
+		break;
+
+	default:
+		assert(0);
+		break;
+	}
+
+	ds->dsg_offset = 0;
+	ds->dsg_kind = DSG_PLOADED;
+}
+
+CodeFieldDesig(df, ds)
+	register struct def *df;
+	register struct desig *ds;
+{
+	/* Generate code for a field designator. Only the code common for
+	   address as well as value computation is generated, and the
+	   resulting information on where to find the designator is placed
+	   in "ds". "df" indicates the definition of the field.
+	*/
+
+	register struct withdesig *wds;
+
+	if (ds->dsg_kind == DSG_INIT) {
+		/* In a WITH statement. We must find the designator in the
+		   WITH statement, and act as if the field is a selection
+		   of this designator.
+		   So, first find the right WITH statement, which is the
+		   first one of the proper record type.
+		   Notice that the proper record type is recognized by its
+		   scope indication.
+		*/
+		wds = WithDesigs;
+		assert(wds != 0);
+
+		while (wds->w_scope != df->df_scope) {
+			wds = wds->w_next;
+			assert(wds != 0);
+		}
+
+		/* Found it. Now, act like it was a selection.
+		*/
+		*ds = wds->w_desig;
+	}
+
+	switch(ds->dsg_kind) {
+	case DSG_PLOADED:
+	case DSG_FIXED:
+		ds->dsg_offset += df->fld_off;
+		break;
+
+	case DSG_PFIXED:
+	case DSG_INDEXED:
+		CodeAddress(ds);
+		ds->dsg_kind = PLOADED;
+		ds->dsg_offset = df->fld_off;
+		break;
+
+	default:
+		assert(0);
+		break;
+	}
+}
+