[PATCH 0/1] MR10496: vbscript: Return error 1045 for non-literal constant expressions.

[Francis De Brabandere (＠francisdb)]

When a Const declaration uses a non-literal expression (e.g.
"Const x = 1 + \"a\""), Windows parses the full expression and then
rejects it with error 1045 ("expected literal constant").

Change ConstDecl to accept Expression instead of ConstExpression, and
validate in new_const_decl() that the expression is a literal or
negated numeric literal. Remove the now-unused ConstExpression rule.

This fixes both the error code (was generic E_FAIL/16389) and the
error character position (now points to the end of the expression).

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10496

[PATCH 1/1] vbscript: Return error 1045 for non-literal constant expressions.

[Francis De Brabandere]

From: Francis De Brabandere <[e-mail]>

When a Const declaration uses a non-literal expression (e.g.
"Const x = 1 + \"a\""), Windows parses the full expression and then
rejects it with error 1045 ("expected literal constant").

Change ConstDecl to accept Expression instead of ConstExpression, and
validate in new_const_decl() that the expression is a literal or
negated numeric literal. Remove the now-unused ConstExpression rule.

This fixes both the error code (was generic E_FAIL/16389) and the
error character position (now points to the end of the expression).
---
 dlls/vbscript/parser.y    | 35 +++++++++++++++++++++++++++++------
 dlls/vbscript/tests/run.c |  4 ++--
 2 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/dlls/vbscript/parser.y b/dlls/vbscript/parser.y
index c1a5b944268..b332c21ef57 100644
--- a/dlls/vbscript/parser.y
+++ b/dlls/vbscript/parser.y
@@ -144,7 +144,7 @@ static statement_t *link_statements(statement_t*,statement_t*);
 %type <expression> Expression LiteralExpression PrimaryExpression EqualityExpression CallExpression ExpressionNl_opt
 %type <expression> ConcatExpression AdditiveExpression ModExpression IntdivExpression MultiplicativeExpression ExpExpression
 %type <expression> UnaryExpression AndExpression OrExpression XorExpression EqvExpression SignExpression
-%type <expression> ConstExpression NumericLiteralExpression
+%type <expression> NumericLiteralExpression
 %type <member> MemberExpression
 %type <expression> Arguments ArgumentList ArgumentList_opt Step_opt ExpressionList
 %type <boolean> DoType Preserve_opt
@@ -294,11 +294,7 @@ ConstDeclList
     | ConstDecl ',' ConstDeclList           { $1->next = $3; $$ = $1; }
 
 ConstDecl
-    : Identifier '=' ConstExpression        { $$ = new_const_decl(ctx, $1, $3); CHECK_ERROR; }
-
-ConstExpression
-    : LiteralExpression                     { $$ = $1; }
-    | '-' NumericLiteralExpression          { $$ = new_unary_expression(ctx, EXPR_NEG, $2); CHECK_ERROR; }
+    : Identifier '=' Expression             { $$ = new_const_decl(ctx, $1, $3); CHECK_ERROR; }
 
 DoType
     : tWHILE        { $$ = TRUE; }
@@ -1182,10 +1178,37 @@ static class_decl_t *add_dim_prop(parser_ctx_t *ctx, class_decl_t *class_decl, d
     return class_decl;
 }
 
+static BOOL is_const_expression(expression_t *expr)
+{
+    switch(expr->type) {
+    case EXPR_INT:
+    case EXPR_DOUBLE:
+    case EXPR_STRING:
+    case EXPR_BOOL:
+    case EXPR_DATE:
+    case EXPR_EMPTY:
+    case EXPR_NULL:
+    case EXPR_NOTHING:
+        return TRUE;
+    case EXPR_NEG: {
+        unary_expression_t *unary = (unary_expression_t*)expr;
+        return unary->subexpr->type == EXPR_INT || unary->subexpr->type == EXPR_DOUBLE;
+    }
+    default:
+        return FALSE;
+    }
+}
+
 static const_decl_t *new_const_decl(parser_ctx_t *ctx, const WCHAR *name, expression_t *expr)
 {
     const_decl_t *decl;
 
+    if(!is_const_expression(expr)) {
+        ctx->hres = MAKE_VBSERROR(VBSE_EXPECTED_LITERAL_CONSTANT);
+        ctx->error_loc = ctx->ptr - ctx->code - 1;
+        return NULL;
+    }
+
     decl = parser_alloc(ctx, sizeof(*decl));
     if(!decl)
         return NULL;
diff --git a/dlls/vbscript/tests/run.c b/dlls/vbscript/tests/run.c
index d3aebff098a..d977fb5cd70 100644
--- a/dlls/vbscript/tests/run.c
+++ b/dlls/vbscript/tests/run.c
@@ -2908,8 +2908,8 @@ static void test_parse_errors(void)
         {
             /* Expected literal constant - error 1045 */
             L"Const x = 1 + \"a\"\n",
-            0, -17,
-            NULL, S_OK, -1045
+            0, 17,
+            NULL, S_OK, 1045
         },
         {
             /* Expected '(' - error 1005 */
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/10496