Java: Simplify instantiation of Guards and ControlFlowReachability.

Author: aschackmull

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

@@ -6,11 +6,12 @@ module;
 
 import java
 private import codeql.controlflow.ControlFlowReachability
-private import semmle.code.java.dataflow.SSA as SSA
+private import semmle.code.java.dataflow.SSA
 private import semmle.code.java.controlflow.Guards as Guards
 
 private module ControlFlowInput implements InputSig<Location, ControlFlowNode, BasicBlock> {
   private import java as J
+  import Ssa
 
   AstNode getEnclosingAstNode(ControlFlowNode node) { node.getAstNode() = result }
 
@@ -27,23 +28,6 @@ private module ControlFlowInput implements InputSig<Location, ControlFlowNode, B
 
   class Expr = J::Expr;
 
-  class SourceVariable = SSA::SsaSourceVariable;
-
-  class SsaDefinition = SSA::SsaVariable;
-
-  class SsaExplicitWrite extends SsaDefinition instanceof SSA::SsaExplicitUpdate {
-    Expr getValue() {
-      super.getDefiningExpr().(VariableAssign).getSource() = result or
-      super.getDefiningExpr().(AssignOp) = result
-    }
-  }
-
-  class SsaPhiDefinition = SSA::SsaPhiNode;
-
-  class SsaUncertainWrite extends SsaDefinition instanceof SSA::SsaUncertainImplicitUpdate {
-    SsaDefinition getPriorDefinition() { result = super.getPriorDef() }
-  }
-
   class GuardValue = Guards::GuardValue;
 
   predicate ssaControlsBranchEdge(SsaDefinition def, BasicBlock bb1, BasicBlock bb2, GuardValue v) {

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

@@ -416,30 +416,8 @@ private module LogicInput_v1 implements GuardsImpl::LogicInputSig {
 }
 
 private module LogicInput_v2 implements GuardsImpl::LogicInputSig {
-  private import semmle.code.java.dataflow.SSA as SSA
-
-  final private class FinalSsaVariable = SSA::SsaVariable;
-
-  class SsaDefinition extends FinalSsaVariable {
-    GuardsInput::Expr getARead() { result = this.getAUse() }
-  }
-
-  class SsaExplicitWrite extends SsaDefinition instanceof SSA::SsaExplicitUpdate {
-    GuardsInput::Expr getValue() {
-      super.getDefiningExpr().(VariableAssign).getSource() = result or
-      super.getDefiningExpr().(AssignOp) = result
-    }
-  }
-
-  class SsaPhiDefinition extends SsaDefinition instanceof SSA::SsaPhiNode {
-    predicate hasInputFromBlock(SsaDefinition inp, BasicBlock bb) {
-      super.hasInputFromBlock(inp, bb)
-    }
-  }
-
-  class SsaParameterInit extends SsaDefinition instanceof SSA::SsaImplicitInit {
-    Parameter getParameter() { super.isParameterDefinition(result) }
-  }
+  private import semmle.code.java.dataflow.SSA
+  import Ssa
 
   predicate additionalNullCheck = LogicInputCommon::additionalNullCheck/4;
 

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

@@ -249,9 +249,9 @@ private predicate impossibleEdge(BasicBlock bb1, BasicBlock bb2) {
 }
 
 private module NullnessConfig implements ControlFlowReachability::ConfigSig {
-  predicate source(ControlFlowNode node, SsaVariable def) { varMaybeNull(def, node, _, _) }
+  predicate source(ControlFlowNode node, SsaDefinition def) { varMaybeNull(def, node, _, _) }
 
-  predicate sink(ControlFlowNode node, SsaVariable def) { varDereference(def, _) = node }
+  predicate sink(ControlFlowNode node, SsaDefinition def) { varDereference(def, _) = node }
 
   predicate barrierValue(GuardValue gv) { gv.isNullness(false) }