From 50f905b82168a1ca2689823dce23e6f80b0cfb47 Mon Sep 17 00:00:00 2001
From: Wolfgang Bumiller <wry.git@bumiller.com>
Date: Fri, 6 Dec 2013 22:41:15 +0100
Subject: [PATCH] adding 'final'

---
 ast.h            |  2 ++
 parser.c         | 21 +++++++++++++++++++++
 tests/final.qc   |  3 +++
 tests/final.tmpl |  5 +++++
 4 files changed, 31 insertions(+)
 create mode 100644 tests/final.qc
 create mode 100644 tests/final.tmpl

diff --git a/ast.h b/ast.h
index 2643413..936a587 100644
--- a/ast.h
+++ b/ast.h
@@ -73,6 +73,8 @@ enum {
      */
     AST_FLAG_ARRAY_INIT    = 1 << 10,
 
+    AST_FLAG_FINAL_DECL    = 1 << 11,
+
     AST_FLAG_LAST,
     AST_FLAG_TYPE_MASK     = (AST_FLAG_VARIADIC | AST_FLAG_NORETURN)
 };
diff --git a/parser.c b/parser.c
index 0e43f50..f531161 100644
--- a/parser.c
+++ b/parser.c
@@ -2862,6 +2862,14 @@ static bool parse_qualifiers(parser_t *parser, bool with_local, int *cvq, bool *
                     return false;
                 }
             }
+            else if (!strcmp(parser_tokval(parser), "final")) {
+                flags |= AST_FLAG_FINAL_DECL;
+                if (!parser_next(parser) || parser->tok != TOKEN_ATTRIBUTE_CLOSE) {
+                    parseerror(parser, "`final` attribute has no parameters, expected `]]`");
+                    *cvq = CV_WRONG;
+                    return false;
+                }
+            }
             else if (!strcmp(parser_tokval(parser), "alias") && !(flags & AST_FLAG_ALIAS)) {
                 flags   |= AST_FLAG_ALIAS;
                 *message = NULL;
@@ -2966,6 +2974,8 @@ static bool parse_qualifiers(parser_t *parser, bool with_local, int *cvq, bool *
             had_var = true;
         else if (!strcmp(parser_tokval(parser), "noref"))
             had_noref = true;
+        else if (!strcmp(parser_tokval(parser), "final"))
+            flags |= AST_FLAG_FINAL_DECL;
         else if (!had_const && !had_var && !had_noref && !had_attrib && !had_static && !flags) {
             return false;
         }
@@ -5289,6 +5299,12 @@ static bool parse_variable(parser_t *parser, ast_block *localblock, bool nofield
                             retval = false;
                             goto cleanup;
                         }
+                        if (old->flags & AST_FLAG_FINAL_DECL) {
+                            parseerror(parser, "cannot redeclare variable `%s`, declared final here: %s:%i",
+                                       var->name, ast_ctx(old).file, ast_ctx(old).line);
+                            retval = false;
+                            goto cleanup;
+                        }
                         proto = (ast_value*)old;
                         if (!ast_istype(old, ast_value)) {
                             parseerror(parser, "internal error: not an ast_value");
@@ -5302,6 +5318,11 @@ static bool parse_variable(parser_t *parser, ast_block *localblock, bool nofield
                             goto cleanup;
                         }
                         proto->expression.flags |= var->expression.flags;
+                        /* copy the context for finals,
+                         * so the error can show where it was actually made 'final'
+                         */
+                        if (proto->expression.flags & AST_FLAG_FINAL_DECL)
+                            ast_ctx(old) = ast_ctx(var);
                         ast_delete(var);
                         var = proto;
                     }
diff --git a/tests/final.qc b/tests/final.qc
new file mode 100644
index 0000000..e55599a
--- /dev/null
+++ b/tests/final.qc
@@ -0,0 +1,3 @@
+float here;
+final float here;
+float here;
diff --git a/tests/final.tmpl b/tests/final.tmpl
new file mode 100644
index 0000000..b754123
--- /dev/null
+++ b/tests/final.tmpl
@@ -0,0 +1,5 @@
+I: final.qc
+D: final keyword
+T: -fail
+C: -std=gmqcc
+F: -no-defs
-- 
2.39.2