Rust: Use shared SuccessorType.

Author: aschackmull

rust/ql/lib/codeql/rust/controlflow/ControlFlowGraph.qll

@@ -1,25 +1,9 @@
 /** Provides classes representing the control flow graph. */
 
 private import internal.ControlFlowGraphImpl
-private import internal.SuccessorType
 private import internal.Scope as Scope
+import codeql.controlflow.SuccessorType
 
 final class CfgScope = Scope::CfgScope;
 
-final class SuccessorType = SuccessorTypeImpl;
-
-final class NormalSuccessor = NormalSuccessorImpl;
-
-final class ConditionalSuccessor = ConditionalSuccessorImpl;
-
-final class BooleanSuccessor = BooleanSuccessorImpl;
-
-final class MatchSuccessor = MatchSuccessorImpl;
-
-final class BreakSuccessor = BreakSuccessorImpl;
-
-final class ContinueSuccessor = ContinueSuccessorImpl;
-
-final class ReturnSuccessor = ReturnSuccessorImpl;
-
 final class CfgNode = Node;

rust/ql/lib/codeql/rust/controlflow/internal/Completion.qll

@@ -1,7 +1,6 @@
 private import codeql.util.Boolean
 private import codeql.rust.controlflow.ControlFlowGraph
 private import rust
-private import SuccessorType
 
 newtype TCompletion =
   TSimpleCompletion() or
@@ -32,7 +31,7 @@ abstract class NormalCompletion extends Completion { }
 
 /** A simple (normal) completion. */
 class SimpleCompletion extends NormalCompletion, TSimpleCompletion {
-  override NormalSuccessor getAMatchingSuccessorType() { any() }
+  override DirectSuccessor getAMatchingSuccessorType() { any() }
 
   // `SimpleCompletion` is the "default" completion type, thus it is valid for
   // any node where there isn't another more specific completion type.
@@ -184,7 +183,7 @@ class MatchCompletion extends TMatchCompletion, ConditionalCompletion {
     e instanceof TryExpr and value = true
   }
 
-  override MatchSuccessor getAMatchingSuccessorType() { result.getValue() = value }
+  override MatchingSuccessor getAMatchingSuccessorType() { result.getValue() = value }
 
   /** Gets the dual match completion. */
   override MatchCompletion getDual() { result = TMatchCompletion(value.booleanNot()) }

rust/ql/lib/codeql/rust/controlflow/internal/ControlFlowGraphImpl.qll

@@ -37,7 +37,7 @@ private module CfgInput implements InputSig<Location> {
   /**
    * Hold if `c` represents simple (normal) evaluation of a statement or an expression.
    */
-  predicate successorTypeIsSimple(SuccessorType t) { t instanceof Cfg::NormalSuccessor }
+  predicate successorTypeIsSimple(SuccessorType t) { t instanceof Cfg::DirectSuccessor }
 
   /** Holds if `t` is an abnormal exit type out of a CFG scope. */
   predicate isAbnormalExitType(SuccessorType t) { none() }

rust/ql/lib/codeql/rust/controlflow/internal/SuccessorType.qll

@@ -65,7 +65,6 @@ module Stages {
   cached
   module CfgStage {
     private import codeql.rust.controlflow.internal.Splitting
-    private import codeql.rust.controlflow.internal.SuccessorType
     private import codeql.rust.controlflow.internal.ControlFlowGraphImpl
     private import codeql.rust.controlflow.CfgNodes
 
@@ -87,8 +86,6 @@ module Stages {
       or
       exists(TConditionalCompletionSplitKind())
       or
-      exists(TNormalSuccessor())
-      or
       exists(AstCfgNode n)
       or
       exists(CallExprCfgNode n | exists(n.getFunction()))