better constant_expression

1 files changed, 31 insertions, 16 deletions

diff --git a/switch.c b/switch.c
index 868a4f2..305914c 100644
--- a/switch.c
+++ b/switch.c
@@ -50,23 +50,22 @@ compare_cases (const void *a,
 }
 
 static gboolean
-constant_expression (ast_t *ast)
+constant_expression (ast_expression_t *expr)
 {
-    GList *list;
-    
-    if (ast->common.type != AST_EXPRESSION)
-	return FALSE;
-
-    switch (ast->expression.common.type)
+    g_assert (((ast_t *)expr)->common.type == AST_EXPRESSION);
+	
+    switch (expr->common.type)
     {
     case AST_INT_LITERAL_EXPRESSION:
     case AST_BOOL_LITERAL_EXPRESSION:
     case AST_NULL_EXPRESSION:
 	return TRUE;
-
+	break;
+	
     case AST_IDENTIFIER_EXPRESSION:
 	/* FIXME: should check if it's a constant */
 	return FALSE;
+	break;
 	
     case AST_LAMBDA_EXPRESSION:
     case AST_CALL_EXPRESSION:
@@ -76,20 +75,36 @@ constant_expression (ast_t *ast)
     case AST_THIS_EXPRESSION:
     case AST_VOID_EXPRESSION:
 	return FALSE;
+	break;
 	
     case AST_UNARY_EXPRESSION:
+	if (!constant_expression (expr->unary.expr))
+	    return FALSE;
+	break;
+	
     case AST_BINARY_EXPRESSION:
+	if (!constant_expression (expr->binary.left))
+	    return FALSE;
+
+	if (!constant_expression (expr->binary.right))
+	    return FALSE;
+	break;
+	
     case AST_TERNARY_EXPRESSION:
-	for (list = ast->common.children->head; list; list = list->next)
-	{
-	    if (!constant_expression (list->data))
-		return FALSE;
-	}
+	if (!constant_expression (expr->ternary.cond))
+	    return FALSE;
 
-	return TRUE;
+	/* FIXME: we could require only the taken branch to be constant */
+	
+	if (!constant_expression (expr->ternary.then_expr))
+	    return FALSE;
+
+	if (!constant_expression (expr->ternary.else_expr))
+	    return FALSE;
+	break;
     }
 
-    return FALSE;
+    return TRUE;
 }
 
 static gboolean
@@ -108,7 +123,7 @@ check_constant_case_expressions (ast_t *ast)
 	/* FIXME: check that we are dealing with a constant expression,
 	 * and store the value of that expression in the case clause
 	 */
-	if (!constant_expression ((ast_t *)ast->case_.expression.expression))
+	if (!constant_expression (ast->case_.expression.expression))
 	{
 	    g_print ("Expression in case clause must be constant\n");