have Z_IsMobjValid2 print an error in console

if mobj pointer is invalid
the callee should handle the behavior

src/core/memory.cpp

@@ -149,6 +149,30 @@ void PoolAllocator::release()
 	allocated_blocks_ = 0;
 }
 
+bool PoolAllocator::ptrcheck(const void* p) const
+{
+	const uintptr_t paddr = reinterpret_cast<uintptr_t>(p);
+
+	ChunkFooter* next = nullptr;
+	for (ChunkFooter* chunk = first_chunk_; chunk != nullptr; chunk = next)
+	{
+		const uintptr_t blockstart = reinterpret_cast<uintptr_t>(chunk->start);
+		const uintptr_t blockend = blockstart + blocks_ * block_size_;
+
+		//CONS_Printf("mobj ptr %lu, block start %lu end %lu\n", paddr, blockstart, blockend);
+
+		if (paddr >= blockstart && paddr < blockend)
+		{
+			return true;
+		}
+
+		next = chunk->next;
+	}
+
+	return false;
+}
+
+
 static LinearMemory g_frame_memory {4 * 1024 * 1024};
 
 void* Z_Frame_Alloc(size_t size)

src/core/memory.h

@@ -65,6 +65,7 @@ public:
 	constexpr size_t allocated_bytes() const noexcept { return allocated_blocks_ * block_size_; };
 
 	void release();
+	bool ptrcheck(const void* p) const;
 };
 
 } // namespace srb2

src/z_zone.cpp

@@ -804,6 +804,27 @@ void* Z_LevelPoolMalloc(size_t size)
 	return p;
 }
 
+boolean Z_IsMobjValid2(void *p, const char *file, INT32 line)
+{
+	//(void)file;
+	//(void)line;
+
+	// mobj was removed
+	// no need to worry here
+	if (p == NULL)
+		return false;
+
+	// mobjs reside in the large pool
+	if (!g_level_large_pool.ptrcheck(p))
+	{
+		//I_Error("invalid mobj! at %s:%d", file, line);
+		CONS_Alert(CONS_ERROR, "invalid mobj! at %s:%d", file, line);
+		return false;
+	}
+
+	return true;
+}
+
 void* Z_LevelPoolCalloc(size_t size)
 {
 	void* p = Z_LevelPoolMalloc(size);

src/z_zone.h

@@ -173,6 +173,8 @@ char *Z_StrDup(const char *in);
 size_t Z_LevelPoolUsage(void);
 void *Z_LevelPoolMalloc(size_t size);
 void *Z_LevelPoolCalloc(size_t size);
+#define Z_IsMobjValid(p) Z_IsMobjValid2(p, __FILE__, __LINE__)
+boolean Z_IsMobjValid2(void *p, const char *file, INT32 line);
 void Z_LevelPoolFree(void *p, size_t size);
 
 // for use with CLEANUP macro