vbscript: Added empty literal support.

dlls/vbscript/compile.c

@@ -196,6 +196,8 @@ static HRESULT compile_expression(compile_ctx_t *ctx, expression_t *expr)
     switch(expr->type) {
     case EXPR_BOOL:
         return push_instr_int(ctx, OP_bool, ((bool_expression_t*)expr)->value);
+    case EXPR_EMPTY:
+        return push_instr(ctx, OP_empty) != -1 ? S_OK : E_OUTOFMEMORY;
     case EXPR_EQUAL:
         return compile_binary_expression(ctx, (binary_expression_t*)expr, OP_equal);
     case EXPR_MEMBER:

dlls/vbscript/interp.c

@@ -251,6 +251,16 @@ static HRESULT interp_string(exec_ctx_t *ctx)
     return stack_push(ctx, &v);
 }
 
+static HRESULT interp_empty(exec_ctx_t *ctx)
+{
+    VARIANT v;
+
+    TRACE("\n");
+
+    V_VT(&v) = VT_EMPTY;
+    return stack_push(ctx, &v);
+}
+
 static HRESULT interp_not(exec_ctx_t *ctx)
 {
     variant_val_t val;

dlls/vbscript/parse.h

@@ -18,6 +18,7 @@
 
 typedef enum {
     EXPR_BOOL,
+    EXPR_EMPTY,
     EXPR_EQUAL,
     EXPR_MEMBER,
     EXPR_NOT,

dlls/vbscript/parser.y

@@ -35,6 +35,7 @@ static int parser_error(const char*);
 
 static void source_add_statement(parser_ctx_t*,statement_t*);
 
+static void *new_expression(parser_ctx_t*,expression_type_t,size_t);
 static expression_t *new_bool_expression(parser_ctx_t*,VARIANT_BOOL);
 static expression_t *new_string_expression(parser_ctx_t*,const WCHAR*);
 static expression_t *new_unary_expression(parser_ctx_t*,expression_type_t,expression_t*);
@@ -145,6 +146,7 @@ LiteralExpression
     : tTRUE                         { $$ = new_bool_expression(ctx, VARIANT_TRUE); CHECK_ERROR; }
     | tFALSE                        { $$ = new_bool_expression(ctx, VARIANT_FALSE); CHECK_ERROR; }
     | tString                       { $$ = new_string_expression(ctx, $1); CHECK_ERROR; }
+    | tEMPTY                        { $$ = new_expression(ctx, EXPR_EMPTY, 0); CHECK_ERROR; }
 
 PrimaryExpression
     : '(' Expression ')'            { $$ = $2; }
@@ -172,7 +174,7 @@ static void parse_complete(parser_ctx_t *ctx, BOOL option_explicit)
     ctx->option_explicit = option_explicit;
 }
 
-static void *new_expression(parser_ctx_t *ctx, expression_type_t type, unsigned size)
+static void *new_expression(parser_ctx_t *ctx, expression_type_t type, size_t size)
 {
     expression_t *expr;
 

dlls/vbscript/tests/lang.vbs

@@ -29,10 +29,13 @@ Call ok(true = true, "true = true is false")
 Call ok(false = false, "false = false is false")
 Call ok(not (true = false), "true = false is true")
 Call ok("x" = "x", """x"" = ""x"" is false")
+Call ok(empty = empty, "empty = empty is false")
+Call ok(empty = "", "empty = """" is false")
 
 Call ok(getVT(false) = "VT_BOOL", "getVT(false) is not VT_BOOL")
 Call ok(getVT(true) = "VT_BOOL", "getVT(true) is not VT_BOOL")
 Call ok(getVT("") = "VT_BSTR", "getVT("""") is not VT_BSTR")
 Call ok(getVT("test") = "VT_BSTR", "getVT(""test"") is not VT_BSTR")
+Call ok(getVT(Empty) = "VT_EMPTY", "getVT(Empty) is not VT_EMPTY")
 
 reportSuccess()

dlls/vbscript/vbscript.h

@@ -76,6 +76,7 @@ typedef enum {
 
 #define OP_LIST                                   \
     X(bool,           1, ARG_INT,     0)          \
+    X(empty,          1, 0,           0)          \
     X(equal,          1, 0,           0)          \
     X(icall,          1, ARG_BSTR,    ARG_UINT)   \
     X(icallv,         1, ARG_BSTR,    ARG_UINT)   \