newer version

1986-04-21 17:27:06 +00:00
parent 6715e3b171
commit 674791bf91
11 changed files with 348 additions and 100 deletions
--- a/lang/m2/comp/walk.c
+++ b/lang/m2/comp/walk.c
@@ -0,0 +1,142 @@
+/* P A R S E   T R E E   W A L K E R */
+
+static char *RcsId = "$Header$";
+
+/*	Routines to walk through parts of the parse tree, and generate
+	code for these parts.
+*/
+
+#include	<em_arith.h>
+#include	<em_label.h>
+#include	<assert.h>
+
+#include	"def.h"
+#include	"type.h"
+#include	"scope.h"
+#include	"main.h"
+#include	"LLlex.h"
+#include	"node.h"
+
+#include	"debug.h"
+
+extern arith	align();
+static int	prclev = 0;
+
+WalkModule(module)
+	register struct def *module;
+{
+	/*	Walk through a module, and all its local definitions.
+		Also generate code for its body.
+	*/
+	register struct def *df = module->mod_scope->sc_def;
+	struct scope *scope;
+
+	scope = CurrentScope;
+	CurrentScope = module->mod_scope;
+	if (!prclev && module->mod_number) {
+		/* This module is a local module, but not within a
+		   procedure. Generate code to allocate storage for its
+		   variables
+		*/
+		arith size = align(CurrentScope->sc_off, word_size);
+
+		if (size == 0) size = word_size;
+		C_df_dnam(&(CurrentScope->sc_name[1]));
+		C_bss_cst(size, (arith) 0, 0);
+	}
+	else if (CurrentScope == Defined->mod_scope) {
+		/* This module is the module currently being compiled.
+		   Again, generate code to allocate storage for its
+		   variables, which all have an explicit name.
+		*/
+		while (df) {
+			if (df->df_kind == D_VARIABLE) {
+				C_df_dnam(df->var_name);
+				C_bss_cst(df->df_type->tp_size, (arith) 0, 0);
+			}
+			df = df->df_nextinscope;
+		}
+	}
+
+	/* Now, walk through it's local definitions
+	*/
+	WalkDef(CurrentScope->sc_def);
+
+	/* Now, generate initialization code for this module.
+	   First call initialization routines for modules defined within
+	   this module.
+	*/
+	CurrentScope->sc_off = 0;
+	C_pro_narg(CurrentScope->sc_name);
+	MkCalls(CurrentScope->sc_def);
+	WalkNode(module->mod_body);
+	C_end(align(-CurrentScope->sc_off, word_size));
+
+	CurrentScope = scope;
+}
+
+WalkProcedure(procedure)
+	struct def *procedure;
+{
+	/*	Walk through the definition of a procedure and all its
+		local definitions
+	*/
+	struct scope *scope = CurrentScope;
+	register struct def *df;
+
+	prclev++;
+	CurrentScope = procedure->prc_scope;
+	
+	WalkDef(CurrentScope->sc_def);
+
+	/* Generate code for this procedure
+	*/
+	C_pro_narg(procedure->prc_name);
+	/* generate calls to initialization routines of modules defined within
+	   this procedure
+	*/
+	MkCalls(CurrentScope->sc_def);
+	WalkNode(procedure->prc_body);
+	C_end(align(-CurrentScope->sc_off, word_size));
+	CurrentScope = scope;
+	prclev--;
+}
+
+WalkDef(df)
+	register struct def *df;
+{
+	/*	Walk through a list of definitions
+	*/
+	while (df) {
+		if (df->df_kind == D_MODULE) {
+			WalkModule(df);
+		}
+		else if (df->df_kind == D_PROCEDURE) {
+			WalkProcedure(df);
+		}
+		df = df->df_nextinscope;
+	}
+}
+
+MkCalls(df)
+	register struct def *df;
+{
+	/*	Generate calls to initialization routines of modules
+	*/
+	while (df) {
+		if (df->df_kind == D_MODULE) {
+			C_lxl((arith) 0);
+			C_cal(df->df_scope->sc_name);
+		}
+		df = df->df_nextinscope;
+	}
+}
+
+WalkNode(nd)
+	struct node *nd;
+{
+	/*	Node "nd" represents either a statement or a statement list.
+		Generate code for it.
+	*/
+	/* ??? */
+}