Squirrel: Change SQRefCounted allocator to avoid undefined behaviour

src/3rdparty/squirrel/squirrel/sqapi.cpp

@@ -57,13 +57,12 @@ HSQUIRRELVM sq_open(SQInteger initialstacksize)
 	SQSharedState *ss;
 	SQVM *v;
 	sq_new(ss, SQSharedState);
-	v = (SQVM *)SQ_MALLOC(sizeof(SQVM));
-	new (v) SQVM(ss);
+	v = new (SQAllocationTag{}) SQVM(ss);
 	ss->_root_vm = v;
 	if(v->Init(nullptr, initialstacksize)) {
 		return v;
 	} else {
-		sq_delete(v, SQVM);
+		sq_delete_refcounted(v, SQVM);
 		return nullptr;
 	}
 	return v;
@@ -75,14 +74,13 @@ HSQUIRRELVM sq_newthread(HSQUIRRELVM friendvm, SQInteger initialstacksize)
 	SQVM *v;
 	ss=_ss(friendvm);
 
-	v= (SQVM *)SQ_MALLOC(sizeof(SQVM));
-	new (v) SQVM(ss);
+	v = new (SQAllocationTag{}) SQVM(ss);
 
 	if(v->Init(friendvm, initialstacksize)) {
 		friendvm->Push(v);
 		return v;
 	} else {
-		sq_delete(v, SQVM);
+		sq_delete_refcounted(v, SQVM);
 		return nullptr;
 	}
 }

src/3rdparty/squirrel/squirrel/sqarray.h

@@ -12,8 +12,7 @@ private:
 	}
 public:
 	static SQArray* Create(SQSharedState *ss,SQInteger nInitialSize){
-		SQArray *newarray=(SQArray*)SQ_MALLOC(sizeof(SQArray));
-		new (newarray) SQArray(ss,nInitialSize);
+		SQArray *newarray = new (SQAllocationTag{}) SQArray(ss,nInitialSize);
 		return newarray;
 	}
 #ifndef NO_GARBAGE_COLLECTOR
@@ -84,7 +83,7 @@ public:
 	}
 	void FinalFree() override
 	{
-		sq_delete(this, SQArray);
+		sq_delete_refcounted(this, SQArray);
 	}
 	SQObjectPtrVec _values;
 };

src/3rdparty/squirrel/squirrel/sqclass.cpp

@@ -147,9 +147,8 @@ void SQInstance::Init(SQSharedState *ss)
 	ADD_TO_CHAIN(&_sharedstate->_gc_chain, this);
 }
 
-SQInstance::SQInstance(SQSharedState *ss, SQClass *c, SQInteger memsize)
+SQInstance::SQInstance(SQSharedState *ss, SQClass *c)
 {
-	_memsize = memsize;
 	_class = c;
 	SQUnsignedInteger nvalues = _class->_defaultvalues.size();
 	for(SQUnsignedInteger n = 0; n < nvalues; n++) {
@@ -158,9 +157,8 @@ SQInstance::SQInstance(SQSharedState *ss, SQClass *c, SQInteger memsize)
 	Init(ss);
 }
 
-SQInstance::SQInstance(SQSharedState *ss, SQInstance *i, SQInteger memsize)
+SQInstance::SQInstance(SQSharedState *ss, SQInstance *i)
 {
-	_memsize = memsize;
 	_class = i->_class;
 	SQUnsignedInteger nvalues = _class->_defaultvalues.size();
 	for(SQUnsignedInteger n = 0; n < nvalues; n++) {

src/3rdparty/squirrel/squirrel/sqclass.h

@@ -31,8 +31,7 @@ struct SQClass : public CHAINABLE_OBJ
 	SQClass(SQSharedState *ss,SQClass *base);
 public:
 	static SQClass* Create(SQSharedState *ss,SQClass *base) {
-		SQClass *newclass = (SQClass *)SQ_MALLOC(sizeof(SQClass));
-		new (newclass) SQClass(ss, base);
+		SQClass *newclass = new (SQAllocationTag{}) SQClass(ss, base);
 		return newclass;
 	}
 	~SQClass();
@@ -55,7 +54,7 @@ public:
 	void Lock() { _locked = true; if(_base) _base->Lock(); }
 	void Release() {
 		if (_hook) { _hook(_typetag,0);}
-		sq_delete(this, SQClass);
+		sq_delete_refcounted(this, SQClass);
 	}
 	void Finalize();
 #ifndef NO_GARBAGE_COLLECTOR
@@ -81,14 +80,13 @@ public:
 struct SQInstance : public SQDelegable
 {
 	void Init(SQSharedState *ss);
-	SQInstance(SQSharedState *ss, SQClass *c, SQInteger memsize);
-	SQInstance(SQSharedState *ss, SQInstance *c, SQInteger memsize);
+	SQInstance(SQSharedState *ss, SQClass *c);
+	SQInstance(SQSharedState *ss, SQInstance *c);
 public:
 	static SQInstance* Create(SQSharedState *ss,SQClass *theclass) {
 
 		SQInteger size = calcinstancesize(theclass);
-		SQInstance *newinst = (SQInstance *)SQ_MALLOC(size);
-		new (newinst) SQInstance(ss, theclass,size);
+		SQInstance *newinst = new (SQSizedAllocationTag(size)) SQInstance(ss, theclass);
 		if(theclass->_udsize) {
 			newinst->_userpointer = ((unsigned char *)newinst) + (size - theclass->_udsize);
 		}
@@ -97,8 +95,7 @@ public:
 	SQInstance *Clone(SQSharedState *ss)
 	{
 		SQInteger size = calcinstancesize(_class);
-		SQInstance *newinst = (SQInstance *)SQ_MALLOC(size);
-		new (newinst) SQInstance(ss, this,size);
+		SQInstance *newinst = new (SQSizedAllocationTag(size)) SQInstance(ss, this);
 		if(_class->_udsize) {
 			newinst->_userpointer = ((unsigned char *)newinst) + (size - _class->_udsize);
 		}
@@ -143,9 +140,7 @@ public:
 	}
 	void FinalFree() override
 	{
-		SQInteger size = _memsize;
-		this->~SQInstance();
-		SQ_FREE(this, size);
+		sq_delete_refcounted(this, SQInstance);
 	}
 	void Finalize() override;
 #ifndef NO_GARBAGE_COLLECTOR
@@ -157,7 +152,6 @@ public:
 	SQClass *_class;
 	SQUserPointer _userpointer;
 	SQRELEASEHOOK _hook;
-	SQInteger _memsize;
 	SQObjectPtr _values[1];
 };
 

src/3rdparty/squirrel/squirrel/sqclosure.h

@@ -10,12 +10,11 @@ private:
 	SQClosure(SQSharedState *ss,SQFunctionProto *func){_function=func; INIT_CHAIN();ADD_TO_CHAIN(&_ss(this)->_gc_chain,this);}
 public:
 	static SQClosure *Create(SQSharedState *ss,SQFunctionProto *func){
-		SQClosure *nc=(SQClosure*)SQ_MALLOC(sizeof(SQClosure));
-		new (nc) SQClosure(ss,func);
+		SQClosure *nc = new (SQAllocationTag{}) SQClosure(ss,func);
 		return nc;
 	}
 	void Release(){
-		sq_delete(this,SQClosure);
+		sq_delete_refcounted(this,SQClosure);
 	}
 	SQClosure *Clone()
 	{
@@ -48,8 +47,7 @@ private:
 	SQGenerator(SQSharedState *ss,SQClosure *closure){_closure=closure;_state=eRunning;_ci._generator=nullptr;INIT_CHAIN();ADD_TO_CHAIN(&_ss(this)->_gc_chain,this);}
 public:
 	static SQGenerator *Create(SQSharedState *ss,SQClosure *closure){
-		SQGenerator *nc=(SQGenerator*)SQ_MALLOC(sizeof(SQGenerator));
-		new (nc) SQGenerator(ss,closure);
+		SQGenerator *nc = new (SQAllocationTag{}) SQGenerator(ss,closure);
 		return nc;
 	}
 	~SQGenerator()
@@ -61,7 +59,7 @@ public:
 		_stack.resize(0);
 		_closure=_null_;}
 	void Release(){
-		sq_delete(this,SQGenerator);
+		sq_delete_refcounted(this,SQGenerator);
 	}
 	bool Yield(SQVM *v);
 	bool Resume(SQVM *v,SQInteger target);
@@ -84,8 +82,7 @@ private:
 public:
 	static SQNativeClosure *Create(SQSharedState *ss,SQFUNCTION func)
 	{
-		SQNativeClosure *nc=(SQNativeClosure*)SQ_MALLOC(sizeof(SQNativeClosure));
-		new (nc) SQNativeClosure(ss,func);
+		SQNativeClosure *nc = new (SQAllocationTag{}) SQNativeClosure(ss,func);
 		return nc;
 	}
 	SQNativeClosure *Clone()
@@ -103,7 +100,7 @@ public:
 		REMOVE_FROM_CHAIN(&_ss(this)->_gc_chain,this);
 	}
 	void Release(){
-		sq_delete(this,SQNativeClosure);
+		sq_delete_refcounted(this,SQNativeClosure);
 	}
 #ifndef NO_GARBAGE_COLLECTOR
 	void EnqueueMarkObjectForChildren(SQGCMarkerQueue &queue);

src/3rdparty/squirrel/squirrel/sqfuncproto.h

@@ -97,10 +97,9 @@ public:
 		SQInteger nfunctions,SQInteger noutervalues,
 		SQInteger nlineinfos,SQInteger nlocalvarinfos,SQInteger ndefaultparams)
 	{
-		SQFunctionProto *f;
 		//I compact the whole class and members in a single memory allocation
-		f = (SQFunctionProto *)sq_vm_malloc(_FUNC_SIZE(ninstructions,nliterals,nparameters,nfunctions,noutervalues,nlineinfos,nlocalvarinfos,ndefaultparams));
-		new (f) SQFunctionProto(ninstructions, nliterals, nparameters, nfunctions, noutervalues, nlineinfos, nlocalvarinfos, ndefaultparams);
+		size_t size = _FUNC_SIZE(ninstructions,nliterals,nparameters,nfunctions,noutervalues,nlineinfos,nlocalvarinfos,ndefaultparams);
+		SQFunctionProto *f = new (SQSizedAllocationTag(size)) SQFunctionProto(ninstructions, nliterals, nparameters, nfunctions, noutervalues, nlineinfos, nlocalvarinfos, ndefaultparams);
 		return f;
 	}
 	void Release(){
@@ -110,9 +109,8 @@ public:
 		_DESTRUCT_VECTOR(SQOuterVar,_noutervalues,_outervalues);
 		//_DESTRUCT_VECTOR(SQLineInfo,_nlineinfos,_lineinfos); //not required are 2 integers
 		_DESTRUCT_VECTOR(SQLocalVarInfo,_nlocalvarinfos,_localvarinfos);
-		SQInteger size = _FUNC_SIZE(_ninstructions,_nliterals,_nparameters,_nfunctions,_noutervalues,_nlineinfos,_nlocalvarinfos,_ndefaultparams);
 		this->~SQFunctionProto();
-		sq_vm_free(this,size);
+		SQFunctionProto::SQDeallocate(this);
 	}
 	const SQChar* GetLocal(SQVM *v,SQUnsignedInteger stackbase,SQUnsignedInteger nseq,SQUnsignedInteger nop);
 	SQInteger GetLine(SQInstruction *curr);

src/3rdparty/squirrel/squirrel/sqobject.cpp

@@ -90,7 +90,7 @@ SQUnsignedInteger TranslateIndex(const SQObjectPtr &idx)
 SQWeakRef *SQRefCounted::GetWeakRef(SQObjectType type)
 {
 	if(!_weakref) {
-		sq_new(_weakref,SQWeakRef);
+		_weakref = new (SQAllocationTag{}) SQWeakRef();
 		_weakref->_obj._type = type;
 		_weakref->_obj._unVal.pRefCounted = this;
 	}
@@ -109,7 +109,7 @@ void SQWeakRef::Release() {
 	if(ISREFCOUNTED(_obj._type)) {
 		_obj._unVal.pRefCounted->_weakref = nullptr;
 	}
-	sq_delete(this,SQWeakRef);
+	sq_delete_refcounted(this,SQWeakRef);
 }
 
 bool SQDelegable::GetMetaMethod(SQVM *v,SQMetaMethod mm,SQObjectPtr &res) {

src/3rdparty/squirrel/squirrel/sqobject.h

@@ -54,6 +54,14 @@ enum SQMetaMethod{
 
 #define MINPOWER2 4
 
+struct SQAllocationTag{};
+
+struct SQSizedAllocationTag {
+	size_t alloc_size;
+
+	SQSizedAllocationTag(size_t alloc_size) : alloc_size(alloc_size) {}
+};
+
 struct SQRefCounted
 {
 	SQRefCounted() { _uiRef = 0; _weakref = nullptr; }
@@ -63,23 +71,44 @@ struct SQRefCounted
 	struct SQWeakRef *_weakref;
 	virtual void Release()=0;
 
+	inline void *operator new(size_t size, SQRefCounted *place) = delete;
+	inline void operator delete(void *ptr, SQRefCounted *place) = delete;
+
 	/* Placement new/delete to prevent memory leaks if constructor throws an exception. */
-	inline void *operator new(size_t size, SQRefCounted *place)
+	inline void *operator new(size_t size, SQAllocationTag tag)
+	{
+		size += sizeof(size_t);
+		size_t *ptr = (size_t *)SQ_MALLOC(size);
+		*ptr = size;
+		return ptr + 1;
+	}
+
+	inline static void SQDeallocate(void *ptr)
 	{
-		place->size = size;
-		return place;
+		size_t *base = static_cast<size_t *>(ptr) - 1;
+		SQ_FREE(base, *base);
 	}
 
-	inline void operator delete(void *ptr, SQRefCounted *place)
+	inline void operator delete(void *ptr, SQAllocationTag tag)
 	{
-		SQ_FREE(ptr, place->size);
+		SQDeallocate(ptr);
+	}
+
+	inline void *operator new(size_t size, SQSizedAllocationTag sized_tag)
+	{
+		size_t alloc_size = sized_tag.alloc_size + sizeof(size_t);
+		size_t *ptr = (size_t *)SQ_MALLOC(alloc_size);
+		*ptr = alloc_size;
+		return ptr + 1;
+	}
+
+	inline void operator delete(void *ptr, SQSizedAllocationTag sized_tag)
+	{
+		SQDeallocate(ptr);
 	}
 
 	/* Never used but required. */
 	inline void operator delete(void *ptr) { NOT_REACHED(); }
-
-private:
-	size_t size;
 };
 
 struct SQWeakRef : SQRefCounted

src/3rdparty/squirrel/squirrel/sqstate.cpp

@@ -564,8 +564,7 @@ SQString *SQStringTable::Add(const SQChar *news,SQInteger len)
 			return s; //found
 	}
 
-	SQString *t=(SQString *)SQ_MALLOC(len+sizeof(SQString));
-	new (t) SQString(news, len);
+	SQString *t = new (SQSizedAllocationTag(len + sizeof(SQString))) SQString(news, len);
 	t->_next = _strings[h];
 	_strings[h] = t;
 	_slotused++;
@@ -615,9 +614,7 @@ void SQStringTable::Remove(SQString *bs)
 			else
 				_strings[h] = s->_next;
 			_slotused--;
-			SQInteger slen = s->_len;
-			s->~SQString();
-			SQ_FREE(s,sizeof(SQString) + slen);
+			sq_delete_refcounted(s, SQString);
 			return;
 		}
 		prev = s;

src/3rdparty/squirrel/squirrel/sqtable.h

@@ -45,8 +45,7 @@ private:
 public:
 	static SQTable* Create(SQSharedState *ss,SQInteger nInitialSize)
 	{
-		SQTable *newtable = (SQTable*)SQ_MALLOC(sizeof(SQTable));
-		new (newtable) SQTable(ss, nInitialSize);
+		SQTable *newtable = new (SQAllocationTag{}) SQTable(ss, nInitialSize);
 		newtable->_delegate = nullptr;
 		return newtable;
 	}
@@ -87,7 +86,7 @@ public:
 	}
 	void FinalFree() override
 	{
-		sq_delete(this, SQTable);
+		sq_delete_refcounted(this, SQTable);
 	}
 
 };

src/3rdparty/squirrel/squirrel/squserdata.h

@@ -13,8 +13,7 @@ struct SQUserData : SQDelegable
 	}
 	static SQUserData* Create(SQSharedState *ss, SQInteger size)
 	{
-		SQUserData* ud = (SQUserData*)SQ_MALLOC(sizeof(SQUserData)+(size-1));
-		new (ud) SQUserData(ss, size);
+		SQUserData *ud = new (SQSizedAllocationTag(sizeof(SQUserData)+(size-1))) SQUserData(ss, size);
 		return ud;
 	}
 #ifndef NO_GARBAGE_COLLECTOR
@@ -23,9 +22,7 @@ struct SQUserData : SQDelegable
 #endif
 	void Release() {
 		if (_hook) _hook(_val,_size);
-		SQInteger tsize = _size - 1;
-		this->~SQUserData();
-		SQ_FREE(this, sizeof(SQUserData) + tsize);
+		sq_delete_refcounted(this, SQUserData);
 	}
 
 	SQInteger _size;

src/3rdparty/squirrel/squirrel/squtils.h

@@ -2,14 +2,17 @@
 #ifndef _SQUTILS_H_
 #define _SQUTILS_H_
 
+#include <type_traits>
+
 void *sq_vm_malloc(SQUnsignedInteger size);
 void *sq_vm_realloc(void *p,SQUnsignedInteger oldsize,SQUnsignedInteger size);
 void sq_vm_free(void *p,SQUnsignedInteger size);
 
 #define sq_new(__ptr,__type) {__ptr=(__type *)sq_vm_malloc(sizeof(__type));new (__ptr) __type;}
-#define sq_delete(__ptr,__type) {__ptr->~__type();sq_vm_free(__ptr,sizeof(__type));}
+#define sq_delete(__ptr,__type) {__ptr->~__type();sq_vm_free(__ptr,sizeof(__type));static_assert(!std::is_base_of<SQRefCounted,__type>());}
+#define sq_delete_refcounted(__ptr,__type) {__ptr->~__type();__ptr->SQDeallocate(__ptr);}
 #define SQ_MALLOC(__size) sq_vm_malloc((__size));
-#define SQ_FREE(__ptr,__size) sq_vm_free((__ptr),(__size));
+#define SQ_FREE(__ptr,__size) {sq_vm_free((__ptr),(__size));static_assert(!std::is_base_of<SQRefCounted,std::remove_pointer_t<decltype(__ptr)>>());}
 #define SQ_REALLOC(__ptr,__oldsize,__size) sq_vm_realloc((__ptr),(__oldsize),(__size));
 
 //sqvector mini vector class, supports objects by value

src/3rdparty/squirrel/squirrel/sqvm.h

@@ -122,7 +122,7 @@ public:
 		_callsstack = &_callstackdata[0];
 		_alloccallsstacksize = newsize;
 	}
-	void Release(){ sq_delete(this,SQVM); } //does nothing
+	void Release(){ sq_delete_refcounted(this,SQVM); } //does nothing
 ////////////////////////////////////////////////////////////////////////////
 	//stack functions for the api
 	void Remove(SQInteger n);