Add range checks to emulate same C# behaviour on IL2CPP

Author: yutopp

Packages/net.yutopp.vjson/Runtime/TypeHelper.g.cs

@@ -85,6 +85,10 @@ private static bool ConvertFromDoubleToFloat(double i, out object o) {
         private static bool ConvertFromLongToByte(long i, out object o) {
             try
             {
+                if ( i < 0 )
+                {
+                    throw new OverflowException();
+                }
                 o = checked((byte)i);
                 return true;
             }
@@ -111,6 +115,10 @@ private static bool ConvertFromLongToSbyte(long i, out object o) {
         private static bool ConvertFromLongToChar(long i, out object o) {
             try
             {
+                if ( i < 0 )
+                {
+                    throw new OverflowException();
+                }
                 o = checked((char)i);
                 return true;
             }
@@ -176,6 +184,10 @@ private static bool ConvertFromLongToInt(long i, out object o) {
         private static bool ConvertFromLongToUint(long i, out object o) {
             try
             {
+                if ( i < 0 )
+                {
+                    throw new OverflowException();
+                }
                 o = checked((uint)i);
                 return true;
             }
@@ -189,6 +201,10 @@ private static bool ConvertFromLongToUint(long i, out object o) {
         private static bool ConvertFromLongToUlong(long i, out object o) {
             try
             {
+                if ( i < 0 )
+                {
+                    throw new OverflowException();
+                }
                 o = checked((ulong)i);
                 return true;
             }
@@ -215,6 +231,10 @@ private static bool ConvertFromLongToShort(long i, out object o) {
         private static bool ConvertFromLongToUshort(long i, out object o) {
             try
             {
+                if ( i < 0 )
+                {
+                    throw new OverflowException();
+                }
                 o = checked((ushort)i);
                 return true;
             }

pre-process/generator.py

@@ -2,7 +2,10 @@
 import textwrap
 from string import Template
 
-def is_convertible(from_kind, to_kind):
+def is_convertible(from_kind_tup, to_kind_tup):
+    (from_kind, _) = from_kind_tup
+    (to_kind, _) = to_kind_tup
+
     if from_kind == to_kind:
         return True
 
@@ -11,6 +14,15 @@ def is_convertible(from_kind, to_kind):
 
     return False
 
+def is_signed_to_unsigned(from_kind_tup, to_kind_tup):
+    (_, from_signed) = from_kind_tup
+    (_, to_signed) = to_kind_tup
+
+    if from_signed == "s" and to_signed == "u":
+        return True
+
+    return False
+
 def mk_indent(num):
     return ' ' * (4 * num)
 
@@ -35,20 +47,20 @@ def main(args):
         "string",
     ]
     kinds = {
-        "bool": "bool",
-        "byte": "integer",
-        "sbyte": "integer",
-        "char": "integer",
-        "decimal": "number",
-        "double": "number",
-        "float": "number",
-        "int": "integer",
-        "uint": "integer",
-        "long": "integer",
-        "ulong": "integer",
-        "short": "integer",
-        "ushort": "integer",
-        "string": "string",
+        "bool":    ("bool", "_"),
+        "byte":    ("integer", "u"),
+        "sbyte":   ("integer", "s"),
+        "char":    ("integer", "u"),
+        "decimal": ("number", "_"),
+        "double":  ("number", "_"),
+        "float":   ("number", "_"),
+        "int":     ("integer", "s"),
+        "uint":    ("integer", "u"),
+        "long":    ("integer", "s"),
+        "ulong":   ("integer", "u"),
+        "short":   ("integer", "s"),
+        "ushort":  ("integer", "u"),
+        "string":  ("string", "_"),
     }
 
     from_types = ["bool", "long", "double", "string"]
@@ -108,10 +120,21 @@ def main(args):
             if from_ty == to_ty:
                 continue
 
+            need_signed_check = is_signed_to_unsigned(kinds[from_ty], kinds[to_ty])
+
             output_funcs += textwrap.indent("""
 private static bool ConvertFrom{2}To{3}({0} i, out object o) {{
     try
-    {{
+    {{""".format(from_ty, to_ty, from_ty.capitalize(), to_ty.capitalize()), mk_indent(2))
+
+            if need_signed_check:
+                output_funcs += textwrap.indent("""
+        if ( i < 0 )
+        {{
+            throw new OverflowException();
+        }}""".format(), mk_indent(2))
+
+            output_funcs += textwrap.indent("""
         o = checked(({1})i);
         return true;
     }}