From 9b2fe56d149fa23b03b678de2eb51c4f599d2711 Mon Sep 17 00:00:00 2001
From: Tetralux <tetralux@teknik.io>
Date: Sat, 25 Dec 2021 18:53:20 +0000
Subject: [PATCH] Parse #no_nil on unions

---
 core/odin/ast/ast.odin       | 1 +
 core/odin/parser/parser.odin | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/core/odin/ast/ast.odin b/core/odin/ast/ast.odin
index 260979d89..9db57541b 100644
--- a/core/odin/ast/ast.odin
+++ b/core/odin/ast/ast.odin
@@ -711,6 +711,7 @@ Union_Type :: struct {
 	poly_params:   ^Field_List,
 	align:         ^Expr,
 	is_maybe:      bool,
+	is_no_nil:     bool,
 	where_token:   tokenizer.Token,
 	where_clauses: []^Expr,
 	variants:      []^Expr,
diff --git a/core/odin/parser/parser.odin b/core/odin/parser/parser.odin
index 52d4b5e5a..aade2051a 100644
--- a/core/odin/parser/parser.odin
+++ b/core/odin/parser/parser.odin
@@ -2600,6 +2600,7 @@ parse_operand :: proc(p: ^Parser, lhs: bool) -> ^ast.Expr {
 		poly_params: ^ast.Field_List
 		align:       ^ast.Expr
 		is_maybe:    bool
+		is_no_nil:   bool
 
 		if allow_token(p, .Open_Paren) {
 			param_count: int
@@ -2626,6 +2627,11 @@ parse_operand :: proc(p: ^Parser, lhs: bool) -> ^ast.Expr {
 					error(p, tag.pos, "duplicate union tag '#%s'", tag.text)
 				}
 				is_maybe = true
+			case "no_nil":
+				if is_no_nil {
+					error(p, tag.pos, "duplicate union tag '#%s'", tag.text)
+				}
+				is_no_nil = true
 			case:
 				error(p, tag.pos, "invalid union tag '#%s", tag.text)
 			}
@@ -2669,6 +2675,7 @@ parse_operand :: proc(p: ^Parser, lhs: bool) -> ^ast.Expr {
 		ut.where_token   = where_token
 		ut.where_clauses = where_clauses
 		ut.is_maybe      = is_maybe
+		ut.is_no_nil     = is_no_nil
 
 		return ut