C++: Fix bug and accept test changes.

Author: MathiasVP

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

@@ -1064,8 +1064,15 @@ module BarrierGuardWithIntParam<guardChecksNodeSig/4 guardChecksNode> {
     DataFlowIntegrationInput::Guard g, SsaImpl::Definition def, IRGuards::GuardValue val,
     int indirectionIndex
   ) {
-    IRGuards::Guards_v1::ParameterizedValidationWrapper<int, guardChecksInstr/4>::guardChecksDef(g,
-      def, val, indirectionIndex)
+    exists(Instruction e |
+      IRGuards::Guards_v1::ParameterizedValidationWrapper<int, guardChecksInstr/4>::guardChecks(g,
+        e, val, indirectionIndex)
+    |
+      indirectionIndex = 0 and
+      def.(Definition).getAUse().getDef() = e
+      or
+      def.(Definition).getAnIndirectUse(indirectionIndex).getDef() = e
+    )
   }
 
   Node getABarrierNode(int indirectionIndex) {

cpp/ql/test/library-tests/dataflow/ir-barrier-guards/test.cpp

@@ -4,12 +4,12 @@ void sink(int);
 
 void testCheckArgument(int* p) {
   if (checkArgument(p)) {
-    sink(*p); // $ barrier=int indirect_barrier=int barrier=int* indirect_barrier=int*
+    sink(*p); // $ indirect_barrier=int barrier=int*
   }
 }
 
 void testCheckArgument(int p) {
   if (checkArgument(&p)) {
-    sink(p); // $ barrier=glval<int> indirect_barrier=glval<int> indirect_barrier=int
+    sink(p); // $ barrier=glval<int> indirect_barrier=int
   }
 }

shared/controlflow/codeql/controlflow/Guards.qll

@@ -1364,7 +1364,7 @@ module Make<
       /**
        * Holds if the guard `g` validates the expression `e` upon evaluating to `val`.
        */
-      private predicate guardChecks(Guard g, Expr e, GuardValue val, P par) {
+      predicate guardChecks(Guard g, Expr e, GuardValue val, P par) {
         guardChecks0(g, e, val, par)
         or
         exists(NonOverridableMethodCall call, ParameterPosition ppos, ArgumentPosition apos |