Java/C++: Move SsaReadPosition to shared qlpack.

java/ql/lib/semmle/code/java/dataflow/RangeAnalysis.qll

@@ -66,7 +66,6 @@
 import java
 private import SSA
 private import RangeUtils
-private import semmle.code.java.dataflow.internal.rangeanalysis.SsaReadPositionCommon
 private import semmle.code.java.controlflow.internal.GuardsLogic
 private import semmle.code.java.security.RandomDataSource
 private import SignAnalysis
@@ -80,7 +79,6 @@ module Sem implements Semantic {
   private import java as J
   private import SSA as SSA
   private import RangeUtils as RU
-  private import semmle.code.java.dataflow.internal.rangeanalysis.SsaReadPositionCommon as SsaReadPos
   private import semmle.code.java.controlflow.internal.GuardsLogic as GL
 
   class Expr = J::Expr;
@@ -213,6 +211,12 @@ module Sem implements Semantic {
 
   BasicBlock getABasicBlockSuccessor(BasicBlock bb) { result = bb.getABBSuccessor() }
 
+  private predicate id(BasicBlock x, BasicBlock y) { x = y }
+
+  private predicate idOf(BasicBlock x, int y) = equivalenceRelation(id/2)(x, y)
+
+  int getBlockId1(BasicBlock bb) { idOf(bb, result) }
+
   final private class FinalGuard = GL::Guard;
 
   class Guard extends FinalGuard {
@@ -243,31 +247,14 @@ module Sem implements Semantic {
     Expr getAUse() { result = super.getAUse() }
   }
 
-  class SsaPhiNode extends SsaVariable instanceof SSA::SsaPhiNode { }
+  class SsaPhiNode extends SsaVariable instanceof SSA::SsaPhiNode {
+    predicate hasInputFromBlock(SsaVariable inp, BasicBlock bb) { super.hasInputFromBlock(inp, bb) }
+  }
 
   class SsaExplicitUpdate extends SsaVariable instanceof SSA::SsaExplicitUpdate {
     Expr getDefiningExpr() { result = super.getDefiningExpr() }
   }
 
-  final private class FinalSsaReadPosition = SsaReadPos::SsaReadPosition;
-
-  class SsaReadPosition extends FinalSsaReadPosition {
-    predicate hasReadOfVar(SsaVariable v) { super.hasReadOfVar(v) }
-  }
-
-  class SsaReadPositionPhiInputEdge extends SsaReadPosition instanceof SsaReadPos::SsaReadPositionPhiInputEdge
-  {
-    BasicBlock getOrigBlock() { result = super.getOrigBlock() }
-
-    BasicBlock getPhiBlock() { result = super.getPhiBlock() }
-
-    predicate phiInput(SsaPhiNode phi, SsaVariable inp) { super.phiInput(phi, inp) }
-  }
-
-  class SsaReadPositionBlock extends SsaReadPosition instanceof SsaReadPos::SsaReadPositionBlock {
-    BasicBlock getBlock() { result = super.getBlock() }
-  }
-
   predicate conversionCannotOverflow = safeCast/2;
 }
 
@@ -384,7 +371,6 @@ module JavaLangImpl implements LangSig<Sem, IntDelta> {
 
 module Utils implements UtilSig<Sem, IntDelta> {
   private import RangeUtils as RU
-  private import semmle.code.java.dataflow.internal.rangeanalysis.SsaReadPositionCommon as SsaReadPos
 
   Sem::Guard semEqFlowCond(
     Sem::SsaVariable v, Sem::Expr e, int delta, boolean isEq, boolean testIsTrue
@@ -403,14 +389,6 @@ module Utils implements UtilSig<Sem, IntDelta> {
   }
 
   Sem::Type getTrackedType(Sem::Expr e) { result = e.getType() }
-
-  predicate rankedPhiInput(
-    Sem::SsaPhiNode phi, Sem::SsaVariable inp, Sem::SsaReadPositionPhiInputEdge edge, int r
-  ) {
-    SsaReadPos::rankedPhiInput(phi, inp, edge, r)
-  }
-
-  predicate maxPhiInputRank(Sem::SsaPhiNode phi, int rix) { SsaReadPos::maxPhiInputRank(phi, rix) }
 }
 
 module Bounds implements BoundSig<Location, Sem, IntDelta> {

java/ql/lib/semmle/code/java/dataflow/RangeUtils.qll

@@ -5,7 +5,6 @@
 import java
 private import SSA
 private import semmle.code.java.controlflow.internal.GuardsLogic
-private import semmle.code.java.dataflow.internal.rangeanalysis.SsaReadPositionCommon
 private import semmle.code.java.Constants
 private import semmle.code.java.dataflow.RangeAnalysis
 private import codeql.rangeanalysis.internal.RangeUtils

java/ql/lib/semmle/code/java/dataflow/internal/rangeanalysis/SignAnalysisSpecific.qll

@@ -6,6 +6,8 @@ module Private {
   import semmle.code.java.dataflow.RangeUtils as RU
   private import semmle.code.java.dataflow.SSA as Ssa
   private import semmle.code.java.controlflow.Guards as G
+  private import SsaReadPositionCommon
+  private import semmle.code.java.controlflow.internal.GuardsLogic as GL
   private import Sign
   import Impl
 
@@ -168,7 +170,33 @@ module Private {
 
   predicate ssaRead = RU::ssaRead/2;
 
-  predicate guardControlsSsaRead = RU::guardControlsSsaRead/3;
+  /**
+   * Holds if `guard` directly controls the position `controlled` with the
+   * value `testIsTrue`.
+   */
+  pragma[nomagic]
+  private predicate guardDirectlyControlsSsaRead(
+    Guard guard, SsaReadPosition controlled, boolean testIsTrue
+  ) {
+    guard.directlyControls(controlled.(SsaReadPositionBlock).getBlock(), testIsTrue)
+    or
+    exists(SsaReadPositionPhiInputEdge controlledEdge | controlledEdge = controlled |
+      guard.directlyControls(controlledEdge.getOrigBlock(), testIsTrue) or
+      guard.hasBranchEdge(controlledEdge.getOrigBlock(), controlledEdge.getPhiBlock(), testIsTrue)
+    )
+  }
+
+  /**
+   * Holds if `guard` controls the position `controlled` with the value `testIsTrue`.
+   */
+  predicate guardControlsSsaRead(Guard guard, SsaReadPosition controlled, boolean testIsTrue) {
+    guardDirectlyControlsSsaRead(guard, controlled, testIsTrue)
+    or
+    exists(Guard guard0, boolean testIsTrue0 |
+      GL::implies_v2(guard0, testIsTrue0, guard, testIsTrue) and
+      guardControlsSsaRead(guard0, controlled, testIsTrue0)
+    )
+  }
 }
 
 private module Impl {