From 8c01b70ce75af86644246c21875e13a2430e25d0 Mon Sep 17 00:00:00 2001
From: Max Brunsfeld <maxbrunsfeld@gmail.com>
Date: Sat, 13 Feb 2016 14:01:42 -0800
Subject: [PATCH] Don't skip tokens that are not the start of any non-terminal

---
 .../build_tables/symbols_by_first_symbol_spec.cc       | 10 ++++++++++
 src/compiler/build_tables/symbols_by_first_symbol.cc   |  5 ++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/spec/compiler/build_tables/symbols_by_first_symbol_spec.cc b/spec/compiler/build_tables/symbols_by_first_symbol_spec.cc
index 19508063..b0059212 100644
--- a/spec/compiler/build_tables/symbols_by_first_symbol_spec.cc
+++ b/spec/compiler/build_tables/symbols_by_first_symbol_spec.cc
@@ -61,6 +61,11 @@ describe("symbols_by_first_symbol", [&]() {
           Symbol(2),
         }
       },
+      {
+        Symbol(12, true), {
+          Symbol(12, true),
+        }
+      },
       {
         Symbol(13, true), {
           Symbol(13, true),
@@ -69,6 +74,11 @@ describe("symbols_by_first_symbol", [&]() {
           Symbol(2),
         }
       },
+      {
+        Symbol(14, true), {
+          Symbol(14, true),
+        }
+      },
       {
         Symbol(15, true), {
           Symbol(15, true),
diff --git a/src/compiler/build_tables/symbols_by_first_symbol.cc b/src/compiler/build_tables/symbols_by_first_symbol.cc
index f1da78b4..3c2a7c56 100644
--- a/src/compiler/build_tables/symbols_by_first_symbol.cc
+++ b/src/compiler/build_tables/symbols_by_first_symbol.cc
@@ -21,7 +21,10 @@ map<Symbol, set<Symbol>> symbols_by_first_symbol(const SyntaxGrammar &grammar) {
       if (!production.empty()) {
         Symbol first_symbol = production[0].symbol;
         result[first_symbol].insert(symbol);
-        result[first_symbol].insert(first_symbol);
+
+        for (const ProductionStep &step : production) {
+          result[step.symbol].insert(step.symbol);
+        }
       }
   }