tests/capi: support bitwise operations in luaL_loadbuffer_proto

The `bit32` library has been deprecated in PUC Rio Lua 5.3 [1].
Missed bitwise functions have been replaced by appropriate bitwise
operations [2]. The patch adds support of bitwise operations to
the test `luaL_loadbuffer_proto`.

Bitwise operators introduced in Lua 5.3 breaks parsing in Lua 5.1
and 5.2, to avoid this metamethods in preamble.lua uses a function
`bitwise_op`. It was implemented for bitwise tests added in the
commit d4b91f6 ("tests/lapi: add bitop tests").

1. https://www.lua.org/manual/5.3/manual.html#8.2
2. https://www.lua.org/manual/5.3/manual.html#3.4.2

Author: ligurio

tests/capi/luaL_loadbuffer_proto/lua_grammar.proto

@@ -386,6 +386,13 @@ message BinaryOperator {
 
         /* Arithmetic operators (5.3+). */
         uint32 idiv = 16;
+
+        /* Bitwise operators (5.3+). */
+        uint32 band = 17;
+        uint32 bor = 18;
+        uint32 bxor = 19;
+        uint32 shl = 20;
+        uint32 shr = 21;
     }
 }
 
@@ -395,6 +402,9 @@ message UnaryOperator {
         uint32 negate = 1;
         uint32 not = 2;
         uint32 length = 3;
+
+        /* Bitwise operators (5.3+). */
+        uint32 bnot = 4;
     }
 }
 

tests/capi/luaL_loadbuffer_proto/preamble.lua

@@ -8,6 +8,26 @@ local not_nan_and_nil = function(val)
     return (val ~= val or val == nil) and DEFAULT_NUMBER or val
 end
 
+local function bitwise_op(op_name)
+    return function(...)
+        local n = select('#', ...)
+        local chunk
+        -- Bitwise exclusive OR and bitwise NOT have the same
+        -- operator.
+        if (op_name == '&' or op_name == '|') then
+            assert(n > 1)
+        end
+        if n == 1 then
+            local x = ...
+            chunk = ('return %s %d'):format(op_name, x)
+        else
+            local op_name_ws = (' %s '):format(op_name)
+            chunk = 'return ' .. table.concat({...}, op_name_ws)
+        end
+        return assert(load(chunk))()
+    end
+end
+
 local __add = function(v1, v2)
     return always_number(v1) + always_number(v2)
 end
@@ -76,6 +96,30 @@ local __idiv = function(v1, v2)
     local chunk = ('%d // %d'):format(always_number(v1), always_number(v2))
     return assert(loadstring(chunk))()
 end
+local __band = function(v1, v2)
+    local band = bitwise_op('&')
+    return band(always_number(v1), always_number(v2))
+end
+local __bor = function(v1, v2)
+    local bor = bitwise_op('|')
+    return bor(always_number(v1), always_number(v2))
+end
+local __bxor = function(v1, v2)
+    local bxor = bitwise_op('~')
+    return bxor(always_number(v1), always_number(v2))
+end
+local __bnot = function(v)
+    local bnot = bitwise_op('~')
+    return bnot(always_number(v))
+end
+local __shl = function(v1, v2)
+    local shl = bitwise_op('<<')
+    return shl(always_number(v1), always_number(v2))
+end
+local __shr = function(v1, v2)
+    local shr = bitwise_op('>>')
+    return shr(always_number(v1), always_number(v2))
+end
 
 debug.setmetatable('string', {
     __add = __add,
@@ -89,6 +133,12 @@ debug.setmetatable('string', {
     __pow = __pow,
     __sub = __sub,
     __unm = __unm,
+    __band = __band,
+    __bor= __bor,
+    __bxor = __bxor,
+    __bnot = __bnot,
+    __shl = __shl,
+    __shr = __shr,
 })
 debug.setmetatable(0, {
     __add = __add,

tests/capi/luaL_loadbuffer_proto/serializer.cc

@@ -1185,6 +1185,19 @@ PROTO_TOSTRING(BinaryOperator, op)
 		return "and";
 	case BinopType::kOr:
 		return "or";
+
+#if LUA_VERSION_NUM >= 503
+	case BinopType::kBAnd:
+		return "&";
+	case BinopType::kBOr:
+		return "|";
+	case BinopType::kBXor:
+		return "~";
+	case BinopType::kBShl:
+		return "<<";
+	case BinopType::kBShr:
+		return ">>";
+#endif
 	default:
 		/* Works in most cases. */
 		return "==";
@@ -1201,6 +1214,10 @@ PROTO_TOSTRING(UnaryOperator, op)
 		return "not ";
 	case UnaryopType::kLength:
 		return "#";
+#if LUA_VERSION_NUM >= 503
+	case UnaryopType::kBNot:
+		return "~";
+#endif
 	default:
 		/* Works in most cases. */
 		return "not ";