Future-proofing for CUnit-derived class sizing

beyond-all-reason · Jan 12, 2025 · ed18f16 · ed18f16
1 parent 6cde9cd
commit ed18f16
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Showing 2 changed files with 15 additions and 8 deletions.
diff --git a/rts/Sim/Units/UnitHandler.cpp b/rts/Sim/Units/UnitHandler.cpp
@@ -100,11 +100,6 @@ void CUnitHandler::Init() {
 	GeneralMoveSystem::Init();
 	UnitTrapCheckSystem::Init();
 
-	static_assert(sizeof(CBuilder) >= sizeof(CUnit             ), "");
-	static_assert(sizeof(CBuilder) >= sizeof(CBuilding         ), "");
-	static_assert(sizeof(CBuilder) >= sizeof(CExtractorBuilding), "");
-	static_assert(sizeof(CBuilder) >= sizeof(CFactory          ), "");
-
 	{
 		// set the global (runtime-constant) unit-limit as the sum
 		// of  all team unit-limits, which is *always* <= MAX_UNITS

diff --git a/rts/Sim/Units/UnitMemPool.h b/rts/Sim/Units/UnitMemPool.h
@@ -4,14 +4,26 @@
 #define UNIT_MEMPOOL_H
 
 #include "UnitTypes/Builder.h"
+#include "UnitTypes/Building.h"
+#include "UnitTypes/ExtractorBuilding.h"
+#include "UnitTypes/Factory.h"
+
 #include "Sim/Misc/GlobalConstants.h"
 #include "System/MemPoolTypes.h"
 
+/* Needs manually listing all derived classes to find the biggest,
+ * but we probably can't do better, at least without reflection */
+union LargestDerivedFromCUnit {
+	CBuilder builder;
+	CFactory factory;
+	CBuilding building;
+	CExtractorBuilding extractorBuilding;
+};
+
 #if (defined(__x86_64) || defined(__x86_64__) || defined(_M_X64))
-// CBuilder is (currently) the largest derived unit-type
-typedef StaticMemPoolT<MAX_UNITS, CBuilder> UnitMemPool;
+typedef StaticMemPoolT<MAX_UNITS, LargestDerivedFromCUnit> UnitMemPool;
 #else
-typedef FixedDynMemPoolT<MAX_UNITS / 1000, MAX_UNITS / 32, CBuilder> UnitMemPool;
+typedef FixedDynMemPoolT<MAX_UNITS / 1000, MAX_UNITS / 32, LargestDerivedFromCUnit> UnitMemPool;
 #endif
 
 extern UnitMemPool unitMemPool;