Ssa: Refactor DataFlowIntegration

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowPrivate.qll

@@ -2182,17 +2182,6 @@ module IteratorFlow {
   private module DataFlowIntegrationInput implements IteratorSsa::DataFlowIntegrationInputSig {
     private import codeql.util.Void
 
-    class Expr extends Instruction {
-      Expr() {
-        exists(IRBlock bb, int i |
-          SsaInput::variableRead(bb, i, _, true) and
-          this = bb.getInstruction(i)
-        )
-      }
-
-      predicate hasCfgNode(IRCfg::BasicBlock bb, int i) { bb.getInstruction(i) = this }
-    }
-
     predicate ssaDefHasSource(IteratorSsa::WriteDefinition def) { none() }
 
     predicate allowFlowIntoUncertainDef(IteratorSsa::UncertainWriteDefinition def) { any() }
@@ -2280,7 +2269,7 @@ module IteratorFlow {
     result = n.(SsaIteratorNode).getIteratorFlowNode()
     or
     exists(Ssa::UseImpl use, IRBlock bb, int i |
-      result.(DataFlowIntegrationImpl::ExprNode).getExpr().hasCfgNode(bb, i) and
+      result.(DataFlowIntegrationImpl::ReadNode).readsAt(bb, i, v) and
       use.hasIndexInBlock(bb, i, v) and
       use.getNode() = n
     )

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/SsaImpl.qll

@@ -1154,17 +1154,6 @@ private module SsaImpl = Ssa::Make<Location, IRCfg, SsaInput>;
 private module DataFlowIntegrationInput implements SsaImpl::DataFlowIntegrationInputSig {
   private import codeql.util.Boolean
 
-  class Expr extends Instruction {
-    Expr() {
-      exists(IRBlock bb, int i |
-        variableRead(bb, i, _, true) and
-        this = bb.getInstruction(i)
-      )
-    }
-
-    predicate hasCfgNode(IRCfg::BasicBlock bb, int i) { bb.getInstruction(i) = this }
-  }
-
   predicate ssaDefHasSource(SsaImpl::WriteDefinition def) { none() }
 
   predicate allowFlowIntoUncertainDef(SsaImpl::UncertainWriteDefinition def) { any() }

csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowPrivate.qll

@@ -494,9 +494,9 @@ module SsaFlow {
   Impl::Node asNode(Node n) {
     n = TSsaNode(result)
     or
-    result.(Impl::ExprNode).getExpr() = n.(ExprNode).getControlFlowNode()
+    result.(Impl::ReadNode).getControlFlowNode() = n.(ExprNode).getControlFlowNode()
     or
-    result.(Impl::ExprPostUpdateNode).getExpr() =
+    result.(Impl::PostUpdateReadNode).getControlFlowNode() =
       n.(PostUpdateNode).getPreUpdateNode().(ExprNode).getControlFlowNode()
     or
     result.(Impl::WriteDefSourceNode).getDefinition() = n.(ExplicitParameterNode).getSsaDefinition()

csharp/ql/lib/semmle/code/csharp/dataflow/internal/SsaImpl.qll

@@ -1012,10 +1012,6 @@ deprecated Definition uncertainWriteDefinitionInput(UncertainWriteDefinition def
 private module DataFlowIntegrationInput implements Impl::DataFlowIntegrationInputSig {
   private import codeql.util.Boolean
 
-  class Expr extends ControlFlowNode {
-    predicate hasCfgNode(BasicBlock bb, int i) { this = bb.getNode(i) }
-  }
-
   predicate ssaDefHasSource(Impl::WriteDefinition def) {
     // exclude flow directly from RHS to SSA definition, as we instead want to
     // go from RHS to matching assignable definition, and from there to SSA definition

java/ql/lib/semmle/code/java/dataflow/internal/DataFlowNodes.qll

@@ -40,9 +40,10 @@ module SsaFlow {
   Impl::Node asNode(Node n) {
     n = TSsaNode(result)
     or
-    result.(Impl::ExprNode).getExpr() = n.asExpr()
+    result.(Impl::ReadNode).getControlFlowNode() = n.asExpr().getControlFlowNode()
     or
-    result.(Impl::ExprPostUpdateNode).getExpr() = n.(PostUpdateNode).getPreUpdateNode().asExpr()
+    result.(Impl::PostUpdateReadNode).getControlFlowNode() =
+      n.(PostUpdateNode).getPreUpdateNode().asExpr().getControlFlowNode()
     or
     exists(Parameter p |
       n = TExplicitParameterNode(p) and

java/ql/lib/semmle/code/java/dataflow/internal/SsaImpl.qll

@@ -636,16 +636,6 @@ private class TrackedSsaDef extends Definition {
 private module DataFlowIntegrationInput implements Impl::DataFlowIntegrationInputSig {
   private import java as J
 
-  class Expr instanceof J::Expr {
-    string toString() { result = super.toString() }
-
-    Location getLocation() { result = super.getLocation() }
-
-    predicate hasCfgNode(BasicBlock bb, int i) {
-      super.getControlFlowNode() = bb.(J::BasicBlock).getNode(i)
-    }
-  }
-
   predicate ssaDefHasSource(WriteDefinition def) { def instanceof SsaExplicitWrite }
 
   predicate allowFlowIntoUncertainDef(UncertainWriteDefinition def) {

javascript/ql/lib/semmle/javascript/dataflow/internal/DataFlowPrivate.qll

@@ -1230,12 +1230,12 @@ private predicate samePhi(SsaPhiNode legacyPhi, Ssa2::PhiNode newPhi) {
 
 cached
 Node getNodeFromSsa2(Ssa2::Node node) {
-  result = TSsaUseNode(node.(Ssa2::ExprNode).getExpr())
+  result = TSsaUseNode(node.(Ssa2::ReadNode).getControlFlowNode())
   or
-  result = TExprPostUpdateNode(node.(Ssa2::ExprPostUpdateNode).getExpr())
+  result = TExprPostUpdateNode(node.(Ssa2::PostUpdateReadNode).getControlFlowNode())
   or
   exists(ImplicitThisUse use |
-    node.(Ssa2::ExprPostUpdateNode).getExpr() = use and
+    node.(Ssa2::PostUpdateReadNode).getControlFlowNode() = use and
     result = TImplicitThisUse(use, true)
   )
   or

javascript/ql/lib/semmle/javascript/dataflow/internal/sharedlib/Ssa.qll

@@ -56,12 +56,6 @@ js::ControlFlowNode getARead(Definition def) {
 module SsaDataflowInput implements DataFlowIntegrationInputSig {
   private import codeql.util.Boolean
 
-  class Expr extends js::ControlFlowNode {
-    Expr() { this = any(SsaConfig::SourceVariable v).getAUse() }
-
-    predicate hasCfgNode(js::Cfg::BasicBlock bb, int i) { this = bb.getNode(i) }
-  }
-
   predicate ssaDefHasSource(WriteDefinition def) {
     // This library only handles use-use flow after a post-update, there are no definitions, only uses.
     none()

ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowPrivate.qll

@@ -123,9 +123,10 @@ module SsaFlow {
   Impl::Node asNode(Node n) {
     n = TSsaNode(result)
     or
-    result.(Impl::ExprNode).getExpr() = n.asExpr()
+    result.(Impl::ReadNode).getControlFlowNode() = n.asExpr()
     or
-    result.(Impl::ExprPostUpdateNode).getExpr() = n.(PostUpdateNode).getPreUpdateNode().asExpr()
+    result.(Impl::PostUpdateReadNode).getControlFlowNode() =
+      n.(PostUpdateNode).getPreUpdateNode().asExpr()
     or
     exists(SsaImpl::ParameterExt p |
       n = toParameterNode(p) and

ruby/ql/lib/codeql/ruby/dataflow/internal/SsaImpl.qll

@@ -434,10 +434,6 @@ private module DataFlowIntegrationInput implements Impl::DataFlowIntegrationInpu
   private import codeql.ruby.controlflow.internal.Guards as Guards
   private import codeql.util.Boolean
 
-  class Expr extends Cfg::CfgNodes::ExprCfgNode {
-    predicate hasCfgNode(BasicBlock bb, int i) { this = bb.getNode(i) }
-  }
-
   predicate ssaDefHasSource(WriteDefinition def) {
     any(ParameterExt p).isInitializedBy(def) or def.(Ssa::WriteDefinition).assigns(_)
   }

rust/ql/lib/codeql/rust/dataflow/internal/DataFlowImpl.qll

@@ -123,9 +123,10 @@ module SsaFlow {
   SsaFlow::Node asNode(Node n) {
     n = TSsaNode(result)
     or
-    result.(SsaFlow::ExprNode).getExpr() = n.asExpr()
+    result.(SsaFlow::ReadNode).getControlFlowNode() = n.asExpr().getACfgNode()
     or
-    result.(SsaFlow::ExprPostUpdateNode).getExpr() = n.(PostUpdateNode).getPreUpdateNode().asExpr()
+    result.(SsaFlow::PostUpdateReadNode).getControlFlowNode() =
+      n.(PostUpdateNode).getPreUpdateNode().asExpr().getACfgNode()
   }
 
   predicate localFlowStep(

rust/ql/lib/codeql/rust/dataflow/internal/SsaImpl.qll

@@ -328,16 +328,10 @@ private module Cached {
 import Cached
 private import codeql.rust.dataflow.Ssa
 
-private class ExprAlias = Expr;
-
 private module DataFlowIntegrationInput implements Impl::DataFlowIntegrationInputSig {
   private import codeql.rust.dataflow.internal.DataFlowImpl as DataFlowImpl
   private import codeql.util.Boolean
 
-  class Expr extends ExprAlias {
-    predicate hasCfgNode(BasicBlock bb, int i) { this.getACfgNode() = bb.getNode(i) }
-  }
-
   predicate ssaDefHasSource(WriteDefinition def) { none() } // handled in `DataFlowImpl.qll` instead
 
   private predicate isArg(Call call, Expr e) {

shared/dataflow/codeql/dataflow/VariableCapture.qll

@@ -748,12 +748,6 @@ module Flow<
   private module DataFlowIntegrationInput implements CaptureSsa::DataFlowIntegrationInputSig {
     private import codeql.util.Void
 
-    class Expr instanceof Cfg::ControlFlowNode {
-      string toString() { result = super.toString() }
-
-      predicate hasCfgNode(Cfg::BasicBlock bb, int i) { bb.getNode(i) = this }
-    }
-
     class GuardValue = Void;
 
     class Guard extends Void {
@@ -982,12 +976,12 @@ module Flow<
     n = TSynthSsa(result)
     or
     exists(BasicBlock bb, int i |
-      result.(SsaFlow::ExprNode).getExpr().hasCfgNode(bb, i) and
+      result.(SsaFlow::ReadNode).readsAt(bb, i, cc) and
       ssaReadAt(n, cc, false, bb, i)
     )
     or
     exists(BasicBlock bb, int i |
-      result.(SsaFlow::ExprPostUpdateNode).getExpr().hasCfgNode(bb, i) and
+      result.(SsaFlow::PostUpdateReadNode).readsAt(bb, i, cc) and
       ssaReadAt(n, cc, true, bb, i)
     )
     or