Swift: Use shared SuccessorType.

Author: aschackmull

swift/ql/lib/codeql/swift/controlflow/BasicBlocks.qll

@@ -3,7 +3,6 @@
 private import swift
 private import ControlFlowGraph
 private import internal.ControlFlowGraphImpl as CfgImpl
-private import SuccessorTypes
 private import CfgImpl::BasicBlocks as BasicBlocksImpl
 private import codeql.controlflow.BasicBlock as BB
 

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

@@ -2,11 +2,11 @@
 
 private import swift
 private import BasicBlocks
-private import SuccessorTypes
 private import internal.ControlFlowGraphImpl as CfgImpl
 private import internal.Completion
 private import internal.Scope
 private import internal.ControlFlowElements
+import codeql.controlflow.SuccessorType
 
 /** An AST node with an associated control-flow graph. */
 class CfgScope extends Scope instanceof CfgImpl::CfgScope::Range_ {
@@ -61,72 +61,3 @@ class ControlFlowNode extends CfgImpl::Node {
   /** Holds if this node has more than one successor. */
   final predicate isBranch() { strictcount(this.getASuccessor()) > 1 }
 }
-
-/** The type of a control flow successor. */
-class SuccessorType extends CfgImpl::TSuccessorType {
-  /** Gets a textual representation of successor type. */
-  string toString() { none() }
-}
-
-/** Provides different types of control flow successor types. */
-module SuccessorTypes {
-  /** A normal control flow successor. */
-  class NormalSuccessor extends SuccessorType, CfgImpl::TSuccessorSuccessor {
-    final override string toString() { result = "successor" }
-  }
-
-  /** A conditional control flow successor. */
-  abstract class ConditionalSuccessor extends SuccessorType {
-    boolean value;
-
-    bindingset[value]
-    ConditionalSuccessor() { any() }
-
-    /** Gets the Boolean value of this successor. */
-    final boolean getValue() { result = value }
-
-    override string toString() { result = this.getValue().toString() }
-  }
-
-  /** A Boolean control flow successor. */
-  class BooleanSuccessor extends ConditionalSuccessor, CfgImpl::TBooleanSuccessor {
-    BooleanSuccessor() { this = CfgImpl::TBooleanSuccessor(value) }
-  }
-
-  class BreakSuccessor extends SuccessorType, CfgImpl::TBreakSuccessor {
-    final override string toString() { result = "break" }
-  }
-
-  class ContinueSuccessor extends SuccessorType, CfgImpl::TContinueSuccessor {
-    final override string toString() { result = "continue" }
-  }
-
-  class ReturnSuccessor extends SuccessorType, CfgImpl::TReturnSuccessor {
-    final override string toString() { result = "return" }
-  }
-
-  class MatchingSuccessor extends ConditionalSuccessor, CfgImpl::TMatchingSuccessor {
-    MatchingSuccessor() { this = CfgImpl::TMatchingSuccessor(value) }
-
-    /** Holds if this is a match successor. */
-    predicate isMatch() { value = true }
-
-    override string toString() { if this.isMatch() then result = "match" else result = "no-match" }
-  }
-
-  class FallthroughSuccessor extends SuccessorType, CfgImpl::TFallthroughSuccessor {
-    final override string toString() { result = "fallthrough" }
-  }
-
-  class EmptinessSuccessor extends ConditionalSuccessor, CfgImpl::TEmptinessSuccessor {
-    EmptinessSuccessor() { this = CfgImpl::TEmptinessSuccessor(value) }
-
-    predicate isEmpty() { value = true }
-
-    override string toString() { if this.isEmpty() then result = "empty" else result = "non-empty" }
-  }
-
-  class ExceptionSuccessor extends SuccessorType, CfgImpl::TExceptionSuccessor {
-    override string toString() { result = "exception" }
-  }
-}

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

@@ -8,7 +8,6 @@ private import swift
 private import codeql.swift.controlflow.ControlFlowGraph
 private import ControlFlowElements
 private import ControlFlowGraphImpl
-private import SuccessorTypes
 
 private newtype TCompletion =
   TSimpleCompletion() or
@@ -324,7 +323,7 @@ abstract class NormalCompletion extends Completion {
 
 /** A simple (normal) completion. */
 class SimpleCompletion extends NormalCompletion, TSimpleCompletion {
-  override NormalSuccessor getAMatchingSuccessorType() { any() }
+  override DirectSuccessor getAMatchingSuccessorType() { any() }
 
   override string toString() { result = "simple" }
 }
@@ -468,7 +467,7 @@ class FallthroughCompletion extends Completion, TFallthroughCompletion {
 
   FallthroughCompletion() { this = TFallthroughCompletion(dest) }
 
-  override FallthroughSuccessor getAMatchingSuccessorType() { any() }
+  override DirectSuccessor getAMatchingSuccessorType() { any() }
 
   CaseStmt getDestination() { result = dest }
 

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

@@ -1976,18 +1976,6 @@ private module Cached {
     result = n.(FuncDeclElement).getAst() or
     result = n.(KeyPathElement).getAst()
   }
-
-  cached
-  newtype TSuccessorType =
-    TSuccessorSuccessor() or
-    TBooleanSuccessor(boolean b) { b in [false, true] } or
-    TBreakSuccessor() or
-    TContinueSuccessor() or
-    TReturnSuccessor() or
-    TMatchingSuccessor(boolean match) { match in [false, true] } or
-    TFallthroughSuccessor() or
-    TEmptinessSuccessor(boolean isEmpty) { isEmpty in [false, true] } or
-    TExceptionSuccessor()
 }
 
 import Cached

swift/ql/lib/codeql/swift/controlflow/internal/ControlFlowGraphImplSpecific.qll

@@ -57,22 +57,18 @@ 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::SuccessorTypes::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) {
-    t instanceof Cfg::SuccessorTypes::ExceptionSuccessor
-  }
+  predicate isAbnormalExitType(SuccessorType t) { t instanceof Cfg::ExceptionSuccessor }
 
   /** Hold if `t` represents a conditional successor type. */
   predicate successorTypeIsCondition(SuccessorType t) {
-    t instanceof Cfg::SuccessorTypes::BooleanSuccessor or
-    t instanceof Cfg::SuccessorTypes::BreakSuccessor or
-    t instanceof Cfg::SuccessorTypes::ContinueSuccessor or
-    t instanceof Cfg::SuccessorTypes::MatchingSuccessor or
-    t instanceof Cfg::SuccessorTypes::EmptinessSuccessor
+    t instanceof Cfg::BooleanSuccessor or
+    t instanceof Cfg::BreakSuccessor or
+    t instanceof Cfg::ContinueSuccessor or
+    t instanceof Cfg::MatchingSuccessor or
+    t instanceof Cfg::EmptinessSuccessor
   }
 
   /** Holds if `first` is first executed when entering `scope`. */

swift/ql/lib/codeql/swift/security/PathInjectionExtensions.qll

@@ -108,7 +108,7 @@ private class DefaultPathInjectionBarrier extends PathInjectionBarrier {
       TaintTracking::localTaint(validated, DataFlow::exprNode(normalize.getQualifier())) and
       DataFlow::localExprFlow(normalize, starts.getQualifier()) and
       DataFlow::localFlow(validated, this) and
-      exists(ConditionBlock bb, SuccessorTypes::BooleanSuccessor b |
+      exists(ConditionBlock bb, BooleanSuccessor b |
         bb.getANode().getNode().asAstNode().(IfStmt).getACondition() = getImmediateParent*(starts) and
         b.getValue() = true
       |