codeql: implicit void promotion dev lints

Added to dev only for now since they are spammy.
Also fixed severity annotations for some low prio nightly warnings.

Co-authored-by: Richard Patel <[email protected]>

Author: 2 people

contrib/codeql/dev/ImplicitVoidPromotion.ql

@@ -0,0 +1,46 @@
+/**
+ * @name Implicit Void Ptr to Typed Ptr promotion
+ * @description Implicit conversion from void* to a typed pointer
+ * @kind problem
+ * @problem.severity recommendation
+ * @precision high
+ * @id firedancer-io/implicit-void-promotion
+ */
+
+import cpp
+
+class VoidPointer extends PointerType {
+  VoidPointer() { this.getBaseType().getUnspecifiedType() instanceof VoidType }
+}
+
+predicate implicitVoidPromotion(Type lvalue, Type rvalue) {
+  not lvalue.getUnderlyingType() instanceof VoidPointer and
+  rvalue.getUnderlyingType() instanceof VoidPointer
+}
+
+predicate allowedSourceFile(File file) { file.getBaseName() != "fd_types.c" }
+
+class BroadAssign extends Locatable {
+  BroadAssign() { this instanceof Variable or this instanceof AssignExpr }
+
+  Expr getRExpr() {
+    result = this.(Variable).getInitializer().getExpr() or
+    result = this.(AssignExpr).getRValue()
+  }
+
+  Type getLType() {
+    result = this.(Variable).getType() or
+    result = this.(AssignExpr).getLValue().getType()
+  }
+
+  Type getRType() { result = this.getRExpr().getType() }
+}
+
+from BroadAssign assign
+where
+  implicitVoidPromotion(assign.getLType(), assign.getRType()) and
+  allowedSourceFile(assign.getLocation().getFile()) and
+  not assign.getRExpr().isInMacroExpansion() and
+  not assign.getRExpr().hasExplicitConversion() and
+  not assign.getRExpr().(FunctionCall).getTarget().getName().matches("fd_type_pun%")
+select assign, "Implicit conversion from void * to " + assign.getLType()

contrib/codeql/nightly/TrivialMemcpy.ql

@@ -6,7 +6,7 @@
                 to weaker typing.
  * @kind problem
  * @id firedancer-io/trivial-memcpy
- * @problem.severity none
+ * @problem.severity recommendation
  * @precision high
  * @tags maintainability
  *       readability

contrib/codeql/nightly/WrongUnused.ql

@@ -4,7 +4,7 @@
  * @id asymmetric-research/used-unused-param
  * @kind problem
  * @precision high
- * @problem.severity none
+ * @problem.severity recommendation
  */
 
 import cpp