Merge pull request #20300 from aschackmull/cfg/successortype

Shared: Add a shared SuccessorType implementation

java/ql/lib/semmle/code/java/controlflow/BasicBlocks.qll

@@ -7,10 +7,9 @@ module;
 import java
 import Dominance
 private import codeql.controlflow.BasicBlock as BB
+private import codeql.controlflow.SuccessorType
 
 private module Input implements BB::InputSig<Location> {
-  import SuccessorType
-
   /** Hold if `t` represents a conditional successor type. */
   predicate successorTypeIsCondition(SuccessorType t) { none() }
 
@@ -34,7 +33,7 @@ private module Input implements BB::InputSig<Location> {
     result = getASpecificSuccessor(node, t)
     or
     node.getASuccessor() = result and
-    t instanceof NormalSuccessor and
+    t instanceof DirectSuccessor and
     not result = getASpecificSuccessor(node, _)
   }
 
@@ -96,7 +95,7 @@ class BasicBlock extends BbImpl::BasicBlock {
   predicate strictlyDominates(BasicBlock bb) { super.strictlyDominates(bb) }
 
   /** Gets an immediate successor of this basic block of a given type, if any. */
-  BasicBlock getASuccessor(Input::SuccessorType t) { result = super.getASuccessor(t) }
+  BasicBlock getASuccessor(SuccessorType t) { result = super.getASuccessor(t) }
 
   BasicBlock getASuccessor() { result = super.getASuccessor() }
 
@@ -161,8 +160,6 @@ private class BasicBlockAlias = BasicBlock;
 module Cfg implements BB::CfgSig<Location> {
   class ControlFlowNode = BbImpl::ControlFlowNode;
 
-  class SuccessorType = BbImpl::SuccessorType;
-
   class BasicBlock = BasicBlockAlias;
 
   class EntryBasicBlock extends BasicBlock instanceof BbImpl::EntryBasicBlock { }

java/ql/lib/semmle/code/java/controlflow/Guards.qll

@@ -139,10 +139,6 @@ private predicate isNonFallThroughPredecessor(SwitchCase sc, ControlFlowNode pre
   )
 }
 
-private module SuccessorTypes implements SharedGuards::SuccessorTypesSig<SuccessorType> {
-  import SuccessorType
-}
-
 private module GuardsInput implements SharedGuards::InputSig<Location, ControlFlowNode, BasicBlock> {
   private import java as J
   private import semmle.code.java.dataflow.internal.BaseSSA
@@ -379,7 +375,7 @@ private module GuardsInput implements SharedGuards::InputSig<Location, ControlFl
   }
 }
 
-private module GuardsImpl = SharedGuards::Make<Location, Cfg, SuccessorTypes, GuardsInput>;
+private module GuardsImpl = SharedGuards::Make<Location, Cfg, GuardsInput>;
 
 private module LogicInputCommon {
   private import semmle.code.java.dataflow.NullGuards as NullGuards

java/ql/lib/semmle/code/java/controlflow/SuccessorType.qll

@@ -1,74 +0,0 @@
-/**
- * Provides different types of control flow successor types.
- */
-overlay[local?]
-module;
-
-import java
-private import codeql.util.Boolean
-
-private newtype TSuccessorType =
-  TNormalSuccessor() or
-  TBooleanSuccessor(Boolean branch) or
-  TExceptionSuccessor()
-
-/** The type of a control flow successor. */
-class SuccessorType extends TSuccessorType {
-  /** Gets a textual representation of successor type. */
-  string toString() { result = "SuccessorType" }
-}
-
-/** A normal control flow successor. */
-class NormalSuccessor extends SuccessorType, TNormalSuccessor { }
-
-/**
- * An exceptional control flow successor.
- *
- * This marks control flow edges that are taken when an exception is thrown.
- */
-class ExceptionSuccessor extends SuccessorType, TExceptionSuccessor { }
-
-/**
- * A conditional control flow successor.
- *
- * This currently only includes boolean successors (`BooleanSuccessor`).
- */
-class ConditionalSuccessor extends SuccessorType, TBooleanSuccessor {
-  /** Gets the Boolean value of this successor. */
-  boolean getValue() { this = TBooleanSuccessor(result) }
-}
-
-/**
- * A Boolean control flow successor.
- *
- * For example, this program fragment:
- *
- * ```java
- * if (x < 0)
- *     return 0;
- * else
- *     return 1;
- * ```
- *
- * has a control flow graph containing Boolean successors:
- *
- * ```
- *        if
- *        |
- *      x < 0
- *       / \
- *      /   \
- *     /     \
- *  true    false
- *    |        \
- * return 0   return 1
- * ```
- */
-class BooleanSuccessor = ConditionalSuccessor;
-
-/**
- * A nullness control flow successor. This is currently unused for Java.
- */
-class NullnessSuccessor extends ConditionalSuccessor {
-  NullnessSuccessor() { none() }
-}