Merge pull request #946 from github/lcartey/cpp-conversions2

Implement `Conversions2` rule package

Author: MichaelRFairhurst

change_notes/2025-08-15-m5-2-2-virtual-base.md

@@ -0,0 +1,5 @@
+ - `M5-2-2` - `PointerToAVirtualBaseClassCastToAPointer.ql`:
+   - Report casts where the from or to types are typedefs to virtual base classes or derived classes.
+   - Report casts to a reference type which is a derived type.
+   - Report casts where the base class is the parent of a virtual base class.
+   - The alert message has been updated to refer to the virtual base class derivation.

change_notes/2025-08-18-fix-alert-reporting.md

@@ -0,0 +1,3 @@
+ - `RULE-1-2`, `RULE-23-3`, `RULE-23-5`, `RULE-23-6`:
+   - Results that occur in nested macro invocations are now reported in the macro that defines the contravening code, rather than the macro which is first expanded.
+   - Results the occur in arguments to macro invocations are now reported in at the macro invocation site, instead of the macro definition site.

cpp/autosar/src/rules/A5-2-2/TraditionalCStyleCastsUsed.ql

@@ -16,6 +16,7 @@
 import cpp
 import codingstandards.cpp.autosar
 import codingstandards.cpp.Macro
+import codingstandards.cpp.CStyleCasts
 
 /**
  * Gets the macro (if any) that generated the given `CStyleCast`.
@@ -61,18 +62,10 @@ Macro getGeneratedFrom(CStyleCast c) {
  *    argument type is compatible with a single-argument constructor.
  */
 
-from CStyleCast c, string extraMessage, Locatable l, string supplementary
+from ExplicitUserDefinedCStyleCast c, string extraMessage, Locatable l, string supplementary
 where
   not isExcluded(c, BannedSyntaxPackage::traditionalCStyleCastsUsedQuery()) and
-  not c.isImplicit() and
-  not c.getType() instanceof UnknownType and
-  // For casts in templates that occur on types related to a template parameter, the copy of th
-  // cast in the uninstantiated template is represented as a `CStyleCast` even if in practice all
-  // the instantiations represent it as a `ConstructorCall`. To avoid the common false positive case
-  // of using the functional cast notation to call a constructor we exclude all `CStyleCast`s on
-  // uninstantiated templates, and instead rely on reporting results within instantiations.
-  not c.isFromUninstantiatedTemplate(_) and
-  // Exclude casts created from macro invocations of macros defined by third parties
+  // Not generated from a library macro
   not getGeneratedFrom(c) instanceof LibraryMacro and
   // If the cast was generated from a user-provided macro, then report the macro that generated the
   // cast, as the macro itself may have generated the cast

cpp/autosar/src/rules/M5-2-2/PointerToAVirtualBaseClassCastToAPointer.ql

@@ -15,14 +15,11 @@
 
 import cpp
 import codingstandards.cpp.autosar
+import codingstandards.cpp.rules.pointertoavirtualbaseclasscasttoapointer.PointerToAVirtualBaseClassCastToAPointer
 
-from Cast cast, VirtualBaseClass castFrom, Class castTo
-where
-  not isExcluded(cast, PointersPackage::pointerToAVirtualBaseClassCastToAPointerQuery()) and
-  not cast instanceof DynamicCast and
-  castFrom = cast.getExpr().getType().(PointerType).getBaseType() and
-  cast.getType().(PointerType).getBaseType() = castTo and
-  castTo = castFrom.getADerivedClass+()
-select cast,
-  "A pointer to virtual base class $@ is not cast to a pointer of derived class $@ using a dynamic_cast.",
-  castFrom, castFrom.getName(), castTo, castTo.getName()
+class PointerToAVirtualBaseClassCastToAPointerQuery extends PointerToAVirtualBaseClassCastToAPointerSharedQuery
+{
+  PointerToAVirtualBaseClassCastToAPointerQuery() {
+    this = PointersPackage::pointerToAVirtualBaseClassCastToAPointerQuery()
+  }
+}

cpp/autosar/test/rules/A5-2-2/test.cpp

@@ -2,7 +2,7 @@
 #include <string>
 #include <utility>
 int foo() { return 1; }
-
+// A copy of 8.2,2 test.cpp, but with different cases compliant/non-compliant
 void test_c_style_cast() {
   double f = 3.14;
   std::uint32_t n1 = (std::uint32_t)f; // NON_COMPLIANT - C-style cast

cpp/autosar/test/rules/M5-2-2/PointerToAVirtualBaseClassCastToAPointer.expected

@@ -14,15 +14,28 @@ module MacroUnwrapper<ResultType ResultElement> {
    * Gets a macro invocation that applies to the result element.
    */
   private MacroInvocation getAMacroInvocation(ResultElement re) {
-    result.getAnExpandedElement() = re
+    result.getAnAffectedElement() = re
+  }
+
+  private MacroInvocation getASubsumedMacroInvocation(ResultElement re) {
+    result = getAMacroInvocation(re) and
+    // Only report cases where the element is not located at the macro expansion site
+    // This means we'll report results in macro arguments in the macro argument
+    // location, not within the macro itself.
+    //
+    // Do not join start column values.
+    pragma[only_bind_out](result.getLocation().getStartColumn()) =
+      pragma[only_bind_out](re.getLocation().getStartColumn())
   }
 
   /**
    * Gets the primary macro invocation that generated the result element.
+   *
+   * Does not hold for cases where the result element is located at a macro argument site.
    */
   MacroInvocation getPrimaryMacroInvocation(ResultElement re) {
     exists(MacroInvocation mi |
-      mi = getAMacroInvocation(re) and
+      mi = getASubsumedMacroInvocation(re) and
       // No other more specific macro that expands to element
       not exists(MacroInvocation otherMi |
         otherMi = getAMacroInvocation(re) and otherMi.getParentInvocation() = mi

cpp/autosar/test/rules/M5-2-2/PointerToAVirtualBaseClassCastToAPointer.qlref

@@ -0,0 +1,18 @@
+import cpp
+import codingstandards.cpp.Macro
+
+/**
+ * A C-style cast that is explicitly user written and has a known target type.
+ */
+class ExplicitUserDefinedCStyleCast extends CStyleCast {
+  ExplicitUserDefinedCStyleCast() {
+    not this.isImplicit() and
+    not this.getType() instanceof UnknownType and
+    // For casts in templates that occur on types related to a template parameter, the copy of th
+    // cast in the uninstantiated template is represented as a `CStyleCast` even if in practice all
+    // the instantiations represent it as a `ConstructorCall`. To avoid the common false positive case
+    // of using the functional cast notation to call a constructor we exclude all `CStyleCast`s on
+    // uninstantiated templates, and instead rely on reporting results within instantiations.
+    not this.isFromUninstantiatedTemplate(_)
+  }
+}