C#: Use the operation classes where applicable.

Author: michaelnebel

csharp/ql/lib/experimental/code/csharp/Cryptography/NonCryptographicHashes.qll

@@ -48,7 +48,7 @@ private predicate maybeUsedInElfHashFunction(Variable v, Operation xor, Operatio
     Expr e1, Expr e2, AssignExpr addAssign, AssignExpr xorAssign, Operation notOp,
     AssignExpr notAssign
   |
-    (add instanceof AddExpr or add instanceof AssignAddExpr) and
+    add instanceof AddOperation and
     e1.getAChild*() = add.getAnOperand() and
     e1 instanceof BinaryBitwiseOperation and
     e2 = e1.(BinaryBitwiseOperation).getLeftOperand() and

csharp/ql/lib/semmle/code/csharp/controlflow/internal/Completion.qll

@@ -344,7 +344,7 @@ private class TriedControlFlowElement extends ControlFlowElement {
     result instanceof SystemOutOfMemoryExceptionClass
     or
     this =
-      any(AddExpr ae |
+      any(AddOperation ae |
         ae.getType() instanceof StringType and
         result instanceof SystemOutOfMemoryExceptionClass
         or
@@ -353,24 +353,24 @@ private class TriedControlFlowElement extends ControlFlowElement {
       )
     or
     this =
-      any(SubExpr se |
+      any(SubOperation se |
         se.getType() instanceof IntegralType and
         result instanceof SystemOverflowExceptionClass
       )
     or
     this =
-      any(MulExpr me |
+      any(MulOperation me |
         me.getType() instanceof IntegralType and
         result instanceof SystemOverflowExceptionClass
       )
     or
     this =
-      any(DivExpr de |
+      any(DivOperation de |
         not de.getDenominator().getValue().toFloat() != 0 and
         result instanceof SystemDivideByZeroExceptionClass
       )
     or
-    this instanceof RemExpr and
+    this instanceof RemOperation and
     result instanceof SystemDivideByZeroExceptionClass
     or
     this instanceof DynamicExpr and

csharp/ql/src/Security Features/CWE-119/LocalUnvalidatedArithmetic.ql

@@ -18,7 +18,7 @@
 import csharp
 import semmle.code.csharp.controlflow.Guards
 
-from AddExpr add, VirtualMethodCall taintSrc
+from AddOperation add, VirtualMethodCall taintSrc
 where
   // `add` is performing pointer arithmetic
   add.getType() instanceof PointerType and

csharp/ql/src/experimental/CWE-918/RequestForgery.qll

@@ -211,7 +211,7 @@ module RequestForgery {
   }
 
   private predicate stringConcatStep(DataFlow::Node prev, DataFlow::Node succ) {
-    exists(AddExpr a |
+    exists(AddOperation a |
       a.getLeftOperand() = prev.asExpr()
       or
       a.getRightOperand() = prev.asExpr() and

csharp/ql/src/experimental/Security Features/CWE-759/HashWithoutSalt.ql

@@ -174,7 +174,7 @@ module HashWithoutSaltConfig implements DataFlow::ConfigSig {
       mc.getAnArgument() = node.asExpr()
     )
     or
-    exists(AddExpr e | node.asExpr() = e.getAnOperand()) // password+salt
+    exists(AddOperation e | node.asExpr() = e.getAnOperand()) // password+salt
     or
     exists(InterpolatedStringExpr e | node.asExpr() = e.getAnInsert())
     or