diff --git a/src/compiler/build_tables/lookahead_set.cc b/src/compiler/build_tables/lookahead_set.cc
index 443ba0cd..7b33cca2 100644
--- a/src/compiler/build_tables/lookahead_set.cc
+++ b/src/compiler/build_tables/lookahead_set.cc
@@ -29,7 +29,7 @@ bool LookaheadSet::operator==(const LookaheadSet &other) const {
 bool LookaheadSet::contains(const Symbol &symbol) const {
   if (symbol == rules::END_OF_INPUT()) return eof;
   auto &bits = symbol.is_external() ? external_bits : terminal_bits;
-  return bits.size() > symbol.index && bits[symbol.index];
+  return bits.size() > static_cast<size_t>(symbol.index) && bits[symbol.index];
 }
 
 size_t LookaheadSet::size() const {
@@ -95,7 +95,7 @@ bool LookaheadSet::insert(const Symbol &symbol) {
   }
 
   auto &bits = symbol.is_external() ? external_bits : terminal_bits;
-  if (bits.size() <= symbol.index) {
+  if (bits.size() <= static_cast<size_t>(symbol.index)) {
     bits.resize(symbol.index + 1);
   }
   if (!bits[symbol.index]) {
diff --git a/src/runtime/stack.c b/src/runtime/stack.c
index 6bb59095..92e90661 100644
--- a/src/runtime/stack.c
+++ b/src/runtime/stack.c
@@ -86,15 +86,14 @@ recur:
   self->ref_count--;
   if (self->ref_count > 0) return;
 
-  StackNode *last_predecessor = NULL;
+  StackNode *first_predecessor = NULL;
   if (self->link_count > 0) {
-    unsigned i = 0;
-    for (; i < self->link_count - 1; i++) {
+    for (unsigned i = self->link_count - 1; i > 0; i--) {
       if (self->links[i].tree) ts_tree_release(self->links[i].tree);
       stack_node_release(self->links[i].node, pool);
     }
-    if (self->links[i].tree) ts_tree_release(self->links[i].tree);
-    last_predecessor = self->links[i].node;
+    if (self->links[0].tree) ts_tree_release(self->links[0].tree);
+    first_predecessor = self->links[0].node;
   }
 
   if (pool->size < MAX_NODE_POOL_SIZE) {
@@ -103,8 +102,8 @@ recur:
     ts_free(self);
   }
 
-  if (last_predecessor) {
-    self = last_predecessor;
+  if (first_predecessor) {
+    self = first_predecessor;
     goto recur;
   }
 }
diff --git a/test/compiler/build_tables/parse_item_set_builder_test.cc b/test/compiler/build_tables/parse_item_set_builder_test.cc
index 2884c523..4e2b28e6 100644
--- a/test/compiler/build_tables/parse_item_set_builder_test.cc
+++ b/test/compiler/build_tables/parse_item_set_builder_test.cc
@@ -46,7 +46,7 @@ describe("ParseItemSetBuilder", []() {
           {Symbol::terminal(15), 0, AssociativityNone},
         }, 0}
       }},
-    }, {}, {}, {}};
+    }, {}, {}, {}, {}};
 
     auto production = [&](int variable_index, int production_index) -> const Production & {
       return grammar.variables[variable_index].productions[production_index];
@@ -97,7 +97,7 @@ describe("ParseItemSetBuilder", []() {
         }, 0},
         Production{{}, 0}
       }},
-    }, {}, {}, {}};
+    }, {}, {}, {}, {}};
 
     auto production = [&](int variable_index, int production_index) -> const Production & {
       return grammar.variables[variable_index].productions[production_index];
diff --git a/test/compiler/prepare_grammar/expand_repeats_test.cc b/test/compiler/prepare_grammar/expand_repeats_test.cc
index 244e5c5f..87c8b879 100644
--- a/test/compiler/prepare_grammar/expand_repeats_test.cc
+++ b/test/compiler/prepare_grammar/expand_repeats_test.cc
@@ -15,7 +15,7 @@ describe("expand_repeats", []() {
       {
         Variable{"rule0", VariableTypeNamed, Repeat{Symbol::terminal(0)}},
       },
-      {}, {}, {}
+      {}, {}, {}, {}
     };
 
     auto result = expand_repeats(grammar);
@@ -37,7 +37,7 @@ describe("expand_repeats", []() {
           Repeat{Symbol::terminal(11)},
         })},
       },
-      {}, {}, {}
+      {}, {}, {}, {}
     };
 
     auto result = expand_repeats(grammar);
@@ -62,7 +62,7 @@ describe("expand_repeats", []() {
           Repeat{Symbol::terminal(11)}
         })},
       },
-      {}, {}, {}
+      {}, {}, {}, {}
     };
 
     auto result = expand_repeats(grammar);
@@ -91,7 +91,7 @@ describe("expand_repeats", []() {
           Repeat{Symbol::terminal(4)}
         })},
       },
-      {}, {}, {}
+      {}, {}, {}, {}
     };
 
     auto result = expand_repeats(grammar);
@@ -120,7 +120,7 @@ describe("expand_repeats", []() {
           Repeat{Symbol::terminal(11)},
         })},
       },
-      {}, {}, {}
+      {}, {}, {}, {}
     };
 
     auto result = expand_repeats(grammar);
@@ -147,7 +147,7 @@ describe("expand_repeats", []() {
         Variable{"rule0", VariableTypeNamed, Repeat{Symbol::terminal(10)}},
         Variable{"rule1", VariableTypeNamed, Repeat{Symbol::terminal(11)}},
       },
-      {}, {}, {}
+      {}, {}, {}, {}
     };
 
     auto result = expand_repeats(grammar);
diff --git a/test/compiler/prepare_grammar/extract_tokens_test.cc b/test/compiler/prepare_grammar/extract_tokens_test.cc
index e720ec3c..2e515e89 100644
--- a/test/compiler/prepare_grammar/extract_tokens_test.cc
+++ b/test/compiler/prepare_grammar/extract_tokens_test.cc
@@ -48,9 +48,7 @@ describe("extract_tokens", []() {
           Repeat{Symbol::non_terminal(3)}
         },
       },
-      {},
-      {},
-      {}
+      {}, {}, {}, {}
     });
 
     InitialSyntaxGrammar &syntax_grammar = get<0>(result);
@@ -158,9 +156,7 @@ describe("extract_tokens", []() {
           })
         },
       },
-      {},
-      {},
-      {}
+      {}, {}, {}, {}
     });
 
     InitialSyntaxGrammar &syntax_grammar = get<0>(result);
@@ -189,23 +185,26 @@ describe("extract_tokens", []() {
   });
 
   it("does not move entire rules into the lexical grammar if their content is used elsewhere in the grammar", [&]() {
-    auto result = extract_tokens(InternedGrammar{{
-      Variable{
-        "rule_A",
-        VariableTypeNamed,
-        Rule::seq({ Symbol::non_terminal(1), String{"ab"} })
+    auto result = extract_tokens(InternedGrammar{
+      {
+        Variable{
+          "rule_A",
+          VariableTypeNamed,
+          Rule::seq({ Symbol::non_terminal(1), String{"ab"} })
+        },
+        Variable{
+          "rule_B",
+          VariableTypeNamed,
+          String{"cd"}
+        },
+        Variable{
+          "rule_C",
+          VariableTypeNamed,
+          Rule::seq({ String{"ef"}, String{"cd"} })
+        },
       },
-      Variable{
-        "rule_B",
-        VariableTypeNamed,
-        String{"cd"}
-      },
-      Variable{
-        "rule_C",
-        VariableTypeNamed,
-        Rule::seq({ String{"ef"}, String{"cd"} })
-      },
-    }, {}, {}, {}});
+      {}, {}, {}, {}
+    });
 
     InitialSyntaxGrammar &syntax_grammar = get<0>(result);
     LexicalGrammar &lexical_grammar = get<1>(result);
@@ -275,7 +274,7 @@ describe("extract_tokens", []() {
       {
         { Symbol::non_terminal(1), Symbol::non_terminal(2) }
       },
-      {}
+      {}, {}
     });
 
     InitialSyntaxGrammar &syntax_grammar = get<0>(result);
@@ -296,8 +295,7 @@ describe("extract_tokens", []() {
           String{"y"},
           Pattern{" "},
         },
-        {},
-        {}
+        {}, {}, {}
       });
 
       AssertThat(get<2>(result), Equals(CompileError::none()));
@@ -318,8 +316,7 @@ describe("extract_tokens", []() {
         {
           String{"y"},
         },
-        {},
-        {}
+        {}, {}, {}
       });
 
       AssertThat(get<2>(result), Equals(CompileError::none()));
@@ -349,8 +346,7 @@ describe("extract_tokens", []() {
         {
           Symbol::non_terminal(2),
         },
-        {},
-        {}
+        {}, {}, {}
       });
 
       AssertThat(get<2>(result), Equals(CompileError::none()));
@@ -379,8 +375,7 @@ describe("extract_tokens", []() {
         {
           Symbol::non_terminal(1)
         },
-        {},
-        {}
+        {}, {}, {}
       });
 
       AssertThat(get<2>(result), Equals(CompileError(
@@ -398,8 +393,7 @@ describe("extract_tokens", []() {
         {
           Rule::choice({ Symbol::non_terminal(1), Blank{} })
         },
-        {},
-        {}
+        {}, {}, {}
       });
 
       AssertThat(get<2>(result), Equals(CompileError(
@@ -427,7 +421,8 @@ describe("extract_tokens", []() {
       {},
       {
         Variable{"rule_A", VariableTypeNamed, Symbol::non_terminal(0)}
-      }
+      },
+      {}
     });
 
     AssertThat(get<2>(result), Equals(CompileError(
diff --git a/test/compiler/prepare_grammar/intern_symbols_test.cc b/test/compiler/prepare_grammar/intern_symbols_test.cc
index a0097544..22944f53 100644
--- a/test/compiler/prepare_grammar/intern_symbols_test.cc
+++ b/test/compiler/prepare_grammar/intern_symbols_test.cc
@@ -16,7 +16,8 @@ describe("intern_symbols", []() {
         {"x", VariableTypeNamed, Rule::choice({ NamedSymbol{"y"}, NamedSymbol{"_z"} })},
         {"y", VariableTypeNamed, NamedSymbol{"_z"}},
         {"_z", VariableTypeNamed, String{"stuff"}}
-      }, {}, {}, {}
+      },
+      {}, {}, {}, {}
     };
 
     auto result = intern_symbols(grammar);
@@ -35,7 +36,7 @@ describe("intern_symbols", []() {
         {
           {"x", VariableTypeNamed, NamedSymbol{"y"}},
         },
-        {}, {}, {}
+        {}, {}, {}, {}
       };
 
       auto result = intern_symbols(grammar);
@@ -54,7 +55,7 @@ describe("intern_symbols", []() {
       {
         NamedSymbol{"z"}
       },
-      {}, {}
+      {}, {}, {}
     };
 
     auto result = intern_symbols(grammar);
@@ -84,7 +85,8 @@ describe("intern_symbols", []() {
           VariableTypeNamed,
           NamedSymbol{"z"}
         },
-      }
+      },
+      {}
     };
 
     auto result = intern_symbols(grammar);