Implement nominal class and interface types across declarations and calls

engine/memobj.c

@@ -394,6 +394,40 @@ PH7_PRIVATE sxi32 PH7_CheckVarCompat(ph7_value *pObj, int nType) {
 	}
 	return SXERR_NOMATCH;
 }
+/* Apply only to owned storage. Array copies are made before this walk, so a
+ * wider destination never weakens the source array's leaf contracts. */
+PH7_PRIVATE void PH7_MemObjSetDeclaredType(ph7_value *pValue, sxu32 nType) {
+	ph7_hashmap_node *pNode;
+	ph7_hashmap *pMap;
+	if(nType & MEMOBJ_NAMED) {
+		PH7_VmTypeClass(pValue->pVm, nType, TRUE);
+	} else {
+		nType = 0;
+	}
+	pValue->nDeclaredType = nType;
+	if(nType) {
+		pValue->iFlags = MEMOBJ_VARIABLE;
+	}
+	if(nType && MemObjIsNullReference(pValue)) {
+		pValue->nType = nType & MEMOBJ_TYPEMASK;
+		pValue->x.pOther = 0;
+		if(nType & MEMOBJ_HASHMAP) {
+			pValue->x.pOther = PH7_NewHashmap(pValue->pVm, 0, 0);
+			if(pValue->x.pOther == 0) {
+				PH7_VmMemoryError(pValue->pVm);
+			}
+		}
+	}
+	if((pValue->nType & MEMOBJ_HASHMAP) == 0 || pValue->x.pOther == 0) {
+		return;
+	}
+	pMap = (ph7_hashmap *)pValue->x.pOther;
+	pMap->nDeclaredType = nType & ~MEMOBJ_HASHMAP;
+	for(pNode = pMap->pFirst; pNode; pNode = pNode->pPrev) {
+		ph7_value *pLeaf = (ph7_value *)SySetAt(&pValue->pVm->aMemObj, pNode->nValIdx);
+		PH7_MemObjSetDeclaredType(pLeaf, nType ? pMap->nDeclaredType | (pLeaf->nType & MEMOBJ_HASHMAP) : 0);
+	}
+}
 /*
  * Duplicate safely the contents of a ph7_value if source and
  * destination are of the compatible data types.
@@ -403,6 +437,38 @@ PH7_PRIVATE sxi32 PH7_MemObjSafeStore(ph7_value *pSrc, ph7_value *pDest) {
 	ph7_vm *pVm = (pSrc->nType & MEMOBJ_HASHMAP) ? pDest->pVm : 0;
 	sxu32 nDest = pVm ? pDest->nIdx : SXU32_HIGH;
 	sxi32 bArena = pVm && SySetAt(&pVm->aMemObj, nDest) == pDest;
+	if(pDest->nDeclaredType & MEMOBJ_NAMED) {
+		sxu32 nDeclared = pDest->nDeclaredType;
+		sxi32 iFlags = pDest->iFlags;
+		ph7_value sValue, sPrevious;
+		sxi32 rc;
+		if(PH7_VmTypeCheck(pSrc, nDeclared) != SXRET_OK) {
+			return SXERR_NOMATCH;
+		}
+		/* Retain both payloads until storage has its contract again. Releasing
+		 * the old object/map may invoke a destructor which writes through an
+		 * alias of this binding. The source can also be the destination itself. */
+		PH7_MemObjInit(pDest->pVm, &sValue);
+		PH7_MemObjInit(pDest->pVm, &sPrevious);
+		PH7_MemObjLoad(pSrc, &sValue);
+		PH7_MemObjLoad(pDest, &sPrevious);
+		PH7_MemObjRelease(pDest);
+		pDest->x.pOther = 0;
+		if(MemObjIsNullReference(&sValue)) {
+			rc = SXRET_OK;
+		} else {
+			rc = PH7_MemObjStore(&sValue, pDest);
+			if(bArena) {
+				pDest = (ph7_value *)SySetAt(&pVm->aMemObj, nDest);
+			}
+			pDest->nType = nDeclared & MEMOBJ_TYPEMASK;
+		}
+		PH7_MemObjSetDeclaredType(pDest, nDeclared);
+		pDest->iFlags = iFlags;
+		PH7_MemObjRelease(&sValue);
+		PH7_MemObjRelease(&sPrevious);
+		return rc;
+	}
 	if(pDest->nType == 0 || pDest->nType == MEMOBJ_NULL || pDest->nType == pSrc->nType) {
 		sxu32 nType = pSrc->nType;
 		PH7_MemObjStore(pSrc, pDest);
@@ -465,6 +531,10 @@ PH7_PRIVATE sxi32 PH7_MemObjSafeStore(ph7_value *pSrc, ph7_value *pDest) {
 	} else {
 		return SXERR_NOMATCH;
 	}
+	if(bArena) {
+		pDest = (ph7_value *)SySetAt(&pVm->aMemObj, nDest);
+	}
+	PH7_MemObjSetDeclaredType(pDest, 0);
 	return SXRET_OK;
 }
 /*
@@ -957,7 +1027,10 @@ PH7_PRIVATE sxi32 PH7_MemObjStore(ph7_value *pSrc, ph7_value *pDest) {
 	if((pDest->nType & (MEMOBJ_OBJ | MEMOBJ_HASHMAP)) == MEMOBJ_OBJ) {
 		pObj = (ph7_class_instance *)pDest->x.pOther;
 	}
-	SyMemcpy((const void *) & (*pSrc), &(*pDest), sizeof(ph7_value) - (sizeof(ph7_vm *) + sizeof(SyBlob) + sizeof(sxu32)));
+	pDest->x = pSrc->x;
+	pDest->iFlags = pSrc->iFlags;
+	pDest->nType = pSrc->nType;
+	pDest->nDeclaredType = pSrc->nDeclaredType;
 	rc = SXRET_OK;
 	if(SyBlobLength(&pSrc->sBlob) > 0) {
 		SyBlobReset(&pDest->sBlob);
@@ -976,6 +1049,7 @@ PH7_PRIVATE sxi32 PH7_MemObjStore(ph7_value *pSrc, ph7_value *pDest) {
 		 * Stack destinations have no arena slot and must not be rebound. */
 		pMap = PH7_NewHashmap(pVm, 0, 0);
 		PH7_HashmapDup(pSrcMap, pMap);
+		pMap->nDeclaredType = pSrcMap->nDeclaredType;
 		if(bArena) {
 			pDest = (ph7_value *)SySetAt(&pVm->aMemObj, nDest);
 		}
@@ -991,8 +1065,10 @@ PH7_PRIVATE sxi32 PH7_MemObjStore(ph7_value *pSrc, ph7_value *pDest) {
  * buffer contents,simply point to it.
  */
 PH7_PRIVATE sxi32 PH7_MemObjLoad(ph7_value *pSrc, ph7_value *pDest) {
-	SyMemcpy((const void *) & (*pSrc), &(*pDest),
-			 sizeof(ph7_value) - (sizeof(ph7_vm *) + sizeof(SyBlob) + sizeof(sxu32)));
+	pDest->x = pSrc->x;
+	pDest->iFlags = pSrc->iFlags;
+	pDest->nType = pSrc->nType;
+	pDest->nDeclaredType = pSrc->nDeclaredType;
 	if(pSrc->x.pOther) {
 		if(pSrc->nType & MEMOBJ_HASHMAP) {
 			/* Increment reference count */
@@ -1014,6 +1090,7 @@ PH7_PRIVATE sxi32 PH7_MemObjLoad(ph7_value *pSrc, ph7_value *pDest) {
  * Invalidate any prior representation of a given ph7_value.
  */
 PH7_PRIVATE sxi32 PH7_MemObjRelease(ph7_value *pObj) {
+	pObj->nDeclaredType = 0;
 	if((pObj->nType & MEMOBJ_NULL) == 0) {
 		if(pObj->x.pOther) {
 			if(pObj->nType & MEMOBJ_HASHMAP) {