Implement deterministic int64 wrapping arithmetic

engine/memobj.c

@@ -1259,7 +1259,7 @@ PH7_PRIVATE sxi32 PH7_MemObjAdd(ph7_value *pObj1, ph7_value *pObj2, int bAddStor
 			sxi64 a, b;
 			a = pObj1->x.iVal;
 			b = pObj2->x.iVal;
-			pObj1->x.iVal = a + b;
+			pObj1->x.iVal = PH7_Int64Add(a, b);
 			MemObjSetType(pObj1, MEMOBJ_INT);
 		}
 	} else {

engine/vm.c

@@ -3775,7 +3775,7 @@ Resume:
 							if(pObj->nType & MEMOBJ_REAL) {
 								pObj->x.rVal++;
 							} else {
-								pObj->x.iVal++;
+								pObj->x.iVal = PH7_Int64Add(pObj->x.iVal, 1);
 							}
 							if(pInstr->iP1) {
 								/* Pre-increment */
@@ -3788,7 +3788,7 @@ Resume:
 							if(pTos->nType & MEMOBJ_REAL) {
 								pTos->x.rVal++;
 							} else {
-								pTos->x.iVal++;
+								pTos->x.iVal = PH7_Int64Add(pTos->x.iVal, 1);
 								MemObjSetType(pTos, MEMOBJ_INT);
 							}
 						}
@@ -3816,7 +3816,7 @@ Resume:
 							if(pObj->nType & MEMOBJ_REAL) {
 								pObj->x.rVal--;
 							} else {
-								pObj->x.iVal--;
+								pObj->x.iVal = PH7_Int64Sub(pObj->x.iVal, 1);
 							}
 							if(pInstr->iP1) {
 								/* Pre-decrement */
@@ -3829,7 +3829,7 @@ Resume:
 							if(pTos->nType & MEMOBJ_REAL) {
 								pTos->x.rVal--;
 							} else {
-								pTos->x.iVal--;
+								pTos->x.iVal = PH7_Int64Sub(pTos->x.iVal, 1);
 								MemObjSetType(pTos, MEMOBJ_INT);
 							}
 						}
@@ -3854,7 +3854,7 @@ Resume:
 					pTos->x.rVal = -pTos->x.rVal;
 				}
 				if(pTos->nType & MEMOBJ_INT) {
-					pTos->x.iVal = -pTos->x.iVal;
+					pTos->x.iVal = PH7_Int64Neg(pTos->x.iVal);
 				}
 				break;
 			/*
@@ -3905,7 +3905,7 @@ Resume:
 				if((pTos->nType & MEMOBJ_INT) == 0) {
 					PH7_MemObjToInteger(pTos);
 				}
-				pTos->x.iVal = ~pTos->x.iVal;
+				pTos->x.iVal = PH7_Int64FromUnsigned(~(sxu64)pTos->x.iVal);
 				break;
 			/* OP_MUL * * *
 			 * OP_MUL_STORE * * *
@@ -3944,7 +3944,7 @@ Resume:
 						sxi64 a, b, r;
 						a = pNos->x.iVal;
 						b = pTos->x.iVal;
-						r = a * b;
+						r = PH7_Int64Mul(a, b);
 						/* Push the result */
 						pNos->x.iVal = r;
 						MemObjSetType(pNos, MEMOBJ_INT);
@@ -4000,7 +4000,23 @@ Resume:
 						sxi64 a, b, r;
 						a = pNos->x.iVal;
 						b = pTos->x.iVal;
-						r = (sxi64)pow((double)b, (double)a);
+						/* The parser emits the exponent before the base. */
+						if(a < 0) {
+							if(b == 0) {
+								PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Division by zero");
+							}
+							r = b == 1 ? 1 : b == -1 ? ((sxu64)a & 1 ? -1 : 1) : 0;
+						} else {
+							sxu64 base = (sxu64)b, exponent = (sxu64)a, result = 1;
+							while(exponent != 0) {
+								if(exponent & 1) {
+									result *= base;
+								}
+								base *= base;
+								exponent >>= 1;
+							}
+							r = PH7_Int64FromUnsigned(result);
+						}
 						/* Push the result */
 						pNos->x.iVal = r;
 						MemObjSetType(pNos, MEMOBJ_INT);
@@ -4131,7 +4147,7 @@ Resume:
 						sxi64 a, b, r;
 						a = pNos->x.iVal;
 						b = pTos->x.iVal;
-						r = a - b;
+						r = PH7_Int64Sub(a, b);
 						/* Push the result */
 						pNos->x.iVal = r;
 						MemObjSetType(pNos, MEMOBJ_INT);
@@ -4172,7 +4188,7 @@ Resume:
 						sxi64 a, b, r;
 						a = pTos->x.iVal;
 						b = pNos->x.iVal;
-						r = a - b;
+						r = PH7_Int64Sub(a, b);
 						/* Push the result */
 						pNos->x.iVal = r;
 						MemObjSetType(pNos, MEMOBJ_INT);
@@ -4217,7 +4233,7 @@ Resume:
 					if(b == 0) {
 						PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Division by zero %qd%%0", a);
 					} else {
-						r = a % b;
+						r = b == -1 ? 0 : a % b;
 					}
 					/* Push the result */
 					pNos->x.iVal = r;
@@ -4256,7 +4272,7 @@ Resume:
 					if(b == 0) {
 						PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Division by zero %qd%%0", a);
 					} else {
-						r = a % b;
+						r = b == -1 ? 0 : a % b;
 					}
 					/* Push the result */
 					pNos->x.iVal = r;
@@ -4392,16 +4408,16 @@ Resume:
 					switch(pInstr->iOp) {
 						case PH7_OP_BOR_STORE:
 						case PH7_OP_BOR:
-							r = a | b;
+							r = PH7_Int64FromUnsigned((sxu64)a | (sxu64)b);
 							break;
 						case PH7_OP_BXOR_STORE:
 						case PH7_OP_BXOR:
-							r = a ^ b;
+							r = PH7_Int64FromUnsigned((sxu64)a ^ (sxu64)b);
 							break;
 						case PH7_OP_BAND_STORE:
 						case PH7_OP_BAND:
 						default:
-							r = a & b;
+							r = PH7_Int64FromUnsigned((sxu64)a & (sxu64)b);
 							break;
 					}
 					/* Push the result */
@@ -4450,16 +4466,16 @@ Resume:
 					switch(pInstr->iOp) {
 						case PH7_OP_BOR_STORE:
 						case PH7_OP_BOR:
-							r = a | b;
+							r = PH7_Int64FromUnsigned((sxu64)a | (sxu64)b);
 							break;
 						case PH7_OP_BXOR_STORE:
 						case PH7_OP_BXOR:
-							r = a ^ b;
+							r = PH7_Int64FromUnsigned((sxu64)a ^ (sxu64)b);
 							break;
 						case PH7_OP_BAND_STORE:
 						case PH7_OP_BAND:
 						default:
-							r = a & b;
+							r = PH7_Int64FromUnsigned((sxu64)a & (sxu64)b);
 							break;
 					}
 					/* Push the result */
@@ -4506,9 +4522,9 @@ Resume:
 					a = pNos->x.iVal;
 					b = (sxi32)pTos->x.iVal;
 					if(pInstr->iOp == PH7_OP_SHL) {
-						r = a << b;
+						r = PH7_Int64FromUnsigned((sxu64)a << b);
 					} else {
-						r = a >> b;
+						r = PH7_Int64ShiftRight(a, b);
 					}
 					/* Push the result */
 					pNos->x.iVal = r;
@@ -4550,9 +4566,9 @@ Resume:
 					a = pTos->x.iVal;
 					b = (sxi32)pNos->x.iVal;
 					if(pInstr->iOp == PH7_OP_SHL_STORE) {
-						r = a << b;
+						r = PH7_Int64FromUnsigned((sxu64)a << b);
 					} else {
-						r = a >> b;
+						r = PH7_Int64ShiftRight(a, b);
 					}
 					/* Push the result */
 					pNos->x.iVal = r;

include/ph7int.h

@@ -1642,6 +1642,28 @@ enum json_err_code {
 	JSON_ERROR_SYNTAX,    /* Syntax error. */
 	JSON_ERROR_UTF8       /* Malformed UTF-8 characters */
 };
+/* Integer operators retain the low 64 bits, interpreted as two's complement.
+ * Convert only representable unsigned values to signed; arithmetic wraps unsigned.
+ */
+static inline sxi64 PH7_Int64FromUnsigned(sxu64 u) {
+	return u <= (sxu64)SXI64_HIGH ? (sxi64)u : -1 - (sxi64)~u;
+}
+static inline sxi64 PH7_Int64Add(sxi64 a, sxi64 b) {
+	return PH7_Int64FromUnsigned((sxu64)a + (sxu64)b);
+}
+static inline sxi64 PH7_Int64Sub(sxi64 a, sxi64 b) {
+	return PH7_Int64FromUnsigned((sxu64)a - (sxu64)b);
+}
+static inline sxi64 PH7_Int64Mul(sxi64 a, sxi64 b) {
+	return PH7_Int64FromUnsigned((sxu64)a * (sxu64)b);
+}
+static inline sxi64 PH7_Int64Neg(sxi64 a) {
+	return PH7_Int64FromUnsigned((sxu64)0 - (sxu64)a);
+}
+/* The caller supplies a valid shift count (0..63). Avoid signed right shift. */
+static inline sxi64 PH7_Int64ShiftRight(sxi64 a, sxi32 b) {
+	return a < 0 ? -1 - (sxi64)((~(sxu64)a) >> b) : (sxi64)((sxu64)a >> b);
+}
 /* memobj.c function prototypes */
 PH7_PRIVATE sxi32 PH7_MemObjDump(SyBlob *pOut, ph7_value *pObj, int ShowType, int nTab, int nDepth);
 PH7_PRIVATE const char *PH7_MemObjTypeDump(ph7_value *pVal);

modules/json/json.h

@@ -22,7 +22,7 @@
 #define JSON_HEX_QUOT          0x08  /* All " are converted to \u0022. */
 #define JSON_FORCE_OBJECT      0x10  /* Outputs an object rather than an array */
 #define JSON_NUMERIC_CHECK     0x20  /* Encodes numeric strings as numbers. */
-#define JSON_BIGINT_AS_STRING  0x40  /* Not used */
+#define JSON_BIGINT_AS_STRING  0x40  /* Decode big integers as strings. */
 #define JSON_PRETTY_PRINT      0x80  /* Use whitespace in returned data to format it.*/
 #define JSON_UNESCAPED_SLASHES 0x100 /* Don't escape '/' */
 #define JSON_UNESCAPED_UNICODE 0x200 /* Not used */
@@ -54,6 +54,8 @@ struct json_private_data {
 	int isFirst;       /* True if first encoded entry */
 	int iFlags;        /* JSON encoding flags */
 	int nRecCount;     /* Recursion count */
+	sxi32 bObject;     /* True if the current container is encoded as an object */
+	sxi32 bAbort;      /* True if the encoding process was aborted */
 };
 
 /*
@@ -127,4 +129,4 @@ static const ph7_builtin_func jsonFuncList[] = {
 	{"json_decode",    vm_builtin_json_decode }
 };
 
-#endif
+#endif