From 93b5befe45b6464f30f7a9404d1db2d84edf201f Mon Sep 17 00:00:00 2001
From: gingerBill <bill@gingerbill.org>
Date: Sun, 22 Aug 2021 11:27:24 +0100
Subject: [PATCH] Improve error handling for missing semicolon separators in a
 `for` loop

---
 core/odin/parser/parser.odin | 24 ++++++++++++++++++------
 src/parser.cpp               | 26 ++++++++++++++++++--------
 2 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/core/odin/parser/parser.odin b/core/odin/parser/parser.odin
index 8bf159778..6bcb564fe 100644
--- a/core/odin/parser/parser.odin
+++ b/core/odin/parser/parser.odin
@@ -848,12 +848,24 @@ parse_for_stmt :: proc(p: ^Parser) -> ^ast.Stmt {
 		if !is_range && parse_control_statement_semicolon_separator(p) {
 			init = cond;
 			cond = nil;
-			if p.curr_tok.kind != .Semicolon {
-				cond = parse_simple_stmt(p, nil);
-			}
-			expect_semicolon(p, cond);
-			if p.curr_tok.kind != .Open_Brace && p.curr_tok.kind != .Do {
-				post = parse_simple_stmt(p, nil);
+
+
+			if f.curr_tok.kind == .Open_Brace || f.curr_tok.kind == .Do {
+				error(p, f.curr_tok.pos, "Expected ';', followed by a condition expression and post statement, got %s", token.tokens[f.curr_tok.kind]);
+			} else {
+				if p.curr_tok.kind != .Semicolon {
+					cond = parse_simple_stmt(p, nil);
+				}
+
+				if p.curr_tok.text != ";" {
+					error(p, p.curr_tok.pos, "Expected ';', got %s", tokenizer.token_to_string(p.curr_tok));
+				} else {
+					expect_semicolon(p, nil);
+				}
+
+				if p.curr_tok.kind != .Open_Brace && p.curr_tok.kind != .Do {
+					post = parse_simple_stmt(p, nil);
+				}
 			}
 		}
 	}
diff --git a/src/parser.cpp b/src/parser.cpp
index 6184a62ab..e9efd989a 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -4133,16 +4133,26 @@ Ast *parse_for_stmt(AstFile *f) {
 		if (!is_range && parse_control_statement_semicolon_separator(f)) {
 			init = cond;
 			cond = nullptr;
-			if (f->curr_token.kind != Token_Semicolon) {
-				cond = parse_simple_stmt(f, StmtAllowFlag_None);
-			}
-			expect_semicolon(f, cond);
-			if (f->curr_token.kind != Token_OpenBrace &&
-			    f->curr_token.kind != Token_do) {
-				post = parse_simple_stmt(f, StmtAllowFlag_None);
+
+			if (f->curr_token.kind == Token_OpenBrace || f->curr_token.kind == Token_do) {
+				syntax_error(f->curr_token, "Expected ';', followed by a condition expression and post statement, got %.*s", LIT(token_strings[f->curr_token.kind]));
+			} else {
+				if (f->curr_token.kind != Token_Semicolon) {
+					cond = parse_simple_stmt(f, StmtAllowFlag_None);
+				}
+
+				if (f->curr_token.string != ";") {
+					syntax_error(f->curr_token, "Expected ';', got %.*s", LIT(token_to_string(f->curr_token)));
+				} else {
+					expect_semicolon(f, nullptr);
+				}
+
+				if (f->curr_token.kind != Token_OpenBrace &&
+				    f->curr_token.kind != Token_do) {
+					post = parse_simple_stmt(f, StmtAllowFlag_None);
+				}
 			}
 		}
-
 	}