Translation of an AST construct in general takes:

• initial vertex
• target vertex (or two target vertices for conditional statements)

Sequence of statements:

     s1;s2
v0 ---------> v1

becomes

     s1       s2
v0 -----> v -----> v1

That is:

translateStmt(v0, s1; s2, v1) =
  val v = newVertex
  translateStmt(v0,s1,v)
  translateStmt(v,s2,v1)

For simple statements:

translate(v0, Assign(L,R), v1) =
  cfg += (v0, Assign(L,R), v1)

translateCond(v0, p1 && p2, vFalse, vTrue) =
  vp1True = newVertex
  translateCond(v0, p1, vFalse, vp1True)
  translateCond(vp1True, p2, vFalse, vTrue)

Use a global variable for the originating vertex

var pc : Vertex

emit(simpleStmt) = 
  val v = newVertex
  cfg.edges += (pc, simpleStmt, v)
  pc = v

translateStmt(s1; s2; ... sn, vAfter) =
  emit(s1)
  emit(s2)
  ...
  emit(sn)
  pc = vAfter