date and time created 83/02/11 15:44:40 by rrh

SCCS-vsn: usr.bin/struct/struct/3.flow.c 4.1

diff --git a/usr/src/usr.bin/struct/struct/3.flow.c b/usr/src/usr.bin/struct/struct/3.flow.c
new file mode 100644 (file)
index 0000000..74d583d
--- /dev/null
+++ b/usr/src/usr.bin/struct/struct/3.flow.c
@@ -0,0 +1,93 @@
+#ifndef lint
+static char sccsid[] = "@(#)3.flow.c   4.1     (Berkeley)      %G%";
+#endif not lint
+
+#include <stdio.h>
+#
+/*
+correct the flow of control in the new program - use GOTO's which may
+be changed later to NEXT, BREAK, etc.
+*/
+#include "def.h"
+#include "3.def.h"
+
+#define BRANCHTYPE(v)  (NTYPE(v) == GOVX )
+#define HASLEX(t)      (t != GOVX && t != COMPVX && t != ASGOVX  && t != ITERVX )
+                       /* for these, control never flows directly to following statement */
+
+
+getflow()
+       {
+       fixflow(START,UNDEFINED);
+       }
+
+
+fixflow(v,autolex)
+VERT v;
+VERT autolex;          /* lexical successor of v */
+       {
+       VERT lex,chlex,z,x,w;
+       int i;
+       lex = lexval(v,autolex);
+       if (HASLEX(NTYPE(v)) && NTYPE(v) != ICASVX)
+               if (DEFINED(REACH(v)) && REACH(v) != lex)
+                       insib(v,makebr(REACH(v)));
+               else if (NTYPE(v) == DOVX && ARC(v,1) != lex)
+                       insib(v,makebr(ARC(v,1)));
+       if (NTYPE(v) == ITERVX)
+               {
+               BRK(v) = autolex;
+               chlex = v;
+               }
+       else
+               chlex = lexval(v,autolex);
+
+       for (i = 0; i < CHILDNUM(v); ++i)
+               {
+               w = LCHILD(v,i);
+               if (DEFINED(w))
+                       fixflow(w,chlex);
+               else
+                       {
+                       ASSERT(i < ARCNUM(v),fixflow);
+                       z = ARC(v,i);
+                       ASSERT(DEFINED(z), fixflow);
+                       if (z != chlex)
+                               {
+                               x = makebr(z);
+                               LCHILD(v,i) = x;
+                               RSIB(x) = UNDEFINED;
+                               }
+                       }
+               }
+       if (DEFINED(RSIB(v)))
+               fixflow(RSIB(v),autolex);
+       }
+
+
+lexval(v,lastlex)
+VERT v,lastlex;
+       {
+       VERT sib;
+       if (!HASLEX(NTYPE(v))) return(UNDEFINED);
+       sib = RSIB(v);
+       if (NTYPE(v) == ICASVX || NTYPE(v) == ACASVX)
+               return(lastlex);
+       else if (!DEFINED(sib))
+               return(lastlex);
+       else if (BRANCHTYPE(sib))
+               return(ARC(sib,0));
+       else return(sib);
+       }
+
+
+makebr(w)              /* make branching node leading to w */
+VERT w;
+       {
+       VERT new;
+       new = create(GOVX,1);
+       ARC(new,0) = w;
+       RSIB(new) = UNDEFINED;
+       REACH(new) = UNDEFINED;
+       return(new);
+       }