Java: Switch from ssaDefAssigns/ssaDefInitializesParam to ssaDefHasSource.

Author: aschackmull

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

@@ -26,14 +26,27 @@ private predicate deadcode(Expr e) {
 module SsaFlow {
   module Impl = SsaImpl::DataFlowIntegration;
 
+  private predicate ssaDefAssigns(SsaExplicitUpdate def, Expr value) {
+    exists(VariableUpdate upd | upd = def.getDefiningExpr() |
+      value = upd.(VariableAssign).getSource() or
+      value = upd.(AssignOp) or
+      value = upd.(RecordBindingVariableExpr)
+    )
+  }
+
   Impl::Node asNode(Node n) {
     n = TSsaNode(result)
     or
     result.(Impl::ExprNode).getExpr() = n.asExpr()
     or
     result.(Impl::ExprPostUpdateNode).getExpr() = n.(PostUpdateNode).getPreUpdateNode().asExpr()
     or
-    TExplicitParameterNode(result.(Impl::ParameterNode).getParameter()) = n
+    exists(Parameter p |
+      n = TExplicitParameterNode(p) and
+      result.(Impl::WriteDefSourceNode).getDefinition().(SsaImplicitInit).isParameterDefinition(p)
+    )
+    or
+    ssaDefAssigns(result.(Impl::WriteDefSourceNode).getDefinition(), n.asExpr())
   }
 
   predicate localFlowStep(SsaSourceVariable v, Node nodeFrom, Node nodeTo, boolean isUseStep) {

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

@@ -649,21 +649,13 @@ private module DataFlowIntegrationInput implements Impl::DataFlowIntegrationInpu
 
   class Parameter = J::Parameter;
 
-  predicate ssaDefAssigns(Impl::WriteDefinition def, Expr value) {
-    exists(VariableUpdate upd | upd = def.(SsaExplicitUpdate).getDefiningExpr() |
-      value = upd.(VariableAssign).getSource() or
-      value = upd.(AssignOp) or
-      value = upd.(RecordBindingVariableExpr)
-    )
+  predicate ssaDefHasSource(WriteDefinition def) {
+    def instanceof SsaExplicitUpdate or def.(SsaImplicitInit).isParameterDefinition(_)
   }
 
-  predicate ssaDefInitializesParam(Impl::WriteDefinition def, Parameter p) {
-    def.(SsaImplicitInit).getSourceVariable() =
-      any(SsaSourceVariable v |
-        v.getVariable() = p and
-        v.getEnclosingCallable() = p.getCallable()
-      )
-  }
+  predicate ssaDefAssigns(Impl::WriteDefinition def, Expr value) { none() }
+
+  predicate ssaDefInitializesParam(Impl::WriteDefinition def, Parameter p) { none() }
 
   predicate allowFlowIntoUncertainDef(UncertainWriteDefinition def) {
     def instanceof SsaUncertainImplicitUpdate