MEM53-CPP: Remove FP introduced by upgrade to 2.15.5

Flow through realloc was added in the standard library, so move
to barrier instead of node filter

Author: lcartey

cpp/cert/src/rules/MEM53-CPP/ManuallyManagedLifetime.qll

@@ -14,12 +14,15 @@ module AllocToStaticCastConfig implements DataFlow::ConfigSig {
   predicate isSource(DataFlow::Node source) {
     exists(AllocationExpr ae |
       ae.getType().getUnspecifiedType() instanceof VoidPointerType and
-      source.asExpr() = ae and
-      // Ignore realloc, as that memory may already be partially constructed
-      not ae.(FunctionCall).getTarget().getName().toLowerCase().matches("%realloc%")
+      source.asExpr() = ae
     )
   }
 
+  predicate isBarrier(DataFlow::Node sanitizer) {
+    // Ignore realloc, as that memory may already be partially constructed
+    sanitizer.asExpr().(FunctionCall).getTarget().getName().toLowerCase().matches("%realloc%")
+  }
+
   predicate isSink(DataFlow::Node sink) {
     exists(StaticOrCStyleCast sc, Class nonTrivialClass |
       sc.getExpr() = sink.asExpr() and

cpp/cert/test/rules/MEM53-CPP/MissingConstructorCallForManuallyManagedObject.expected

@@ -1,5 +1,4 @@
 edges
-| test.cpp:65:21:65:34 | call to operator new | test.cpp:67:26:67:32 | call to realloc |
 nodes
 | test.cpp:16:26:16:31 | call to malloc | semmle.label | call to malloc |
 | test.cpp:17:38:17:43 | call to malloc | semmle.label | call to malloc |
@@ -10,8 +9,6 @@ nodes
 | test.cpp:47:26:47:39 | call to operator new | semmle.label | call to operator new |
 | test.cpp:49:29:49:42 | call to operator new | semmle.label | call to operator new |
 | test.cpp:51:29:51:42 | call to operator new | semmle.label | call to operator new |
-| test.cpp:65:21:65:34 | call to operator new | semmle.label | call to operator new |
-| test.cpp:67:26:67:32 | call to realloc | semmle.label | call to realloc |
 subpaths
 #select
 | test.cpp:16:26:16:31 | call to malloc | test.cpp:16:26:16:31 | call to malloc | test.cpp:16:26:16:31 | call to malloc | Allocation to cast without constructor call |
@@ -23,4 +20,3 @@ subpaths
 | test.cpp:47:26:47:39 | call to operator new | test.cpp:47:26:47:39 | call to operator new | test.cpp:47:26:47:39 | call to operator new | Allocation to cast without constructor call |
 | test.cpp:49:29:49:42 | call to operator new | test.cpp:49:29:49:42 | call to operator new | test.cpp:49:29:49:42 | call to operator new | Allocation to cast without constructor call |
 | test.cpp:51:29:51:42 | call to operator new | test.cpp:51:29:51:42 | call to operator new | test.cpp:51:29:51:42 | call to operator new | Allocation to cast without constructor call |
-| test.cpp:67:26:67:32 | call to realloc | test.cpp:65:21:65:34 | call to operator new | test.cpp:67:26:67:32 | call to realloc | Allocation to cast without constructor call |

cpp/cert/test/rules/MEM53-CPP/test.cpp

@@ -63,7 +63,6 @@ void test_no_constructor_but_has_destructor() {
 
 void test_realloc() {
   void *goodAlloc = ::operator new(sizeof(ClassA));
-  ClassA *a1 = new (goodAlloc) ClassA{1}; // COMPLIANT
-  ClassA *a2 = (ClassA *)realloc(
-      goodAlloc, sizeof(ClassA) * 2); // COMPLIANT [FALSE_POSITIVE]
+  ClassA *a1 = new (goodAlloc) ClassA{1};                        // COMPLIANT
+  ClassA *a2 = (ClassA *)realloc(goodAlloc, sizeof(ClassA) * 2); // COMPLIANT
 }