From 89bfde29dc2d9fd27fceb5b1de9cdd7bb5389f3a Mon Sep 17 00:00:00 2001
From: Sam Atkins <atkinssj@gmail.com>
Date: Thu, 1 Jul 2021 14:13:48 +0100
Subject: [PATCH] LibWeb: Convert some CSS parser *Rule classes to using
 pointers

Previously these were all passed around by value, but some of them
(StyleComponentValueRule and StyleBlockRule) want to include each
other as fields, so this had to change.
---
 .../Libraries/LibWeb/CSS/Parser/Parser.cpp    | 21 ++++++++---------
 Userland/Libraries/LibWeb/CSS/Parser/Parser.h |  4 ++--
 .../LibWeb/CSS/Parser/QualifiedStyleRule.h    |  7 +++++-
 .../LibWeb/CSS/Parser/StyleBlockRule.h        |  4 ++--
 .../CSS/Parser/StyleComponentValueRule.h      | 23 ++++++++++++++-----
 .../LibWeb/CSS/Parser/StyleFunctionRule.h     |  6 ++---
 .../LibWeb/CSS/Parser/StyleRules.cpp          | 11 +++++----
 7 files changed, 47 insertions(+), 29 deletions(-)

diff --git a/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp b/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
index 6e9f947e1e..4411a6ee32 100644
--- a/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
+++ b/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
@@ -74,7 +74,7 @@ Vector<QualifiedStyleRule> Parser::parse_as_stylesheet()
             dbgln("{}", pre.to_string());
         }
         dbgln("BLOCK:");
-        dbgln("{}", rule.m_block.to_string());
+        dbgln("{}", rule.block().to_string());
         dbgln("");
 
         auto selectors = parse_selectors(rule.m_prelude);
@@ -95,7 +95,7 @@ Vector<CSS::Selector::ComplexSelector> Parser::parse_selectors(Vector<StyleCompo
         if (index >= parts.size())
             return {};
 
-        auto current_value = parts.at(index);
+        auto& current_value = parts.at(index);
         index++;
 
         CSS::Selector::SimpleSelector::Type type;
@@ -246,7 +246,7 @@ Vector<CSS::Selector::ComplexSelector> Parser::parse_selectors(Vector<StyleCompo
                     return simple_selector;
                 }
             } else if (current_value.is_function()) {
-                auto pseudo_function = current_value.function();
+                auto& pseudo_function = current_value.function();
                 if (pseudo_function.name().equals_ignoring_case("nth-child")) {
                     simple_selector.pseudo_class = CSS::Selector::SimpleSelector::PseudoClass::NthChild;
                     simple_selector.nth_child_pattern = CSS::Selector::SimpleSelector::NthChildPattern::parse(pseudo_function.values_as_string());
@@ -469,12 +469,12 @@ StyleComponentValueRule Parser::consume_a_component_value()
     return component;
 }
 
-StyleBlockRule Parser::consume_a_simple_block()
+NonnullRefPtr<StyleBlockRule> Parser::consume_a_simple_block()
 {
     auto ending_token = current_token().mirror_variant();
 
-    StyleBlockRule block;
-    block.m_token = current_token();
+    NonnullRefPtr<StyleBlockRule> block = create<StyleBlockRule>();
+    block->m_token = current_token();
 
     for (;;) {
         auto token = next_token();
@@ -495,14 +495,13 @@ StyleBlockRule Parser::consume_a_simple_block()
                 continue;
             }
         }
-        block.m_values.append(value.to_string());
+        block->m_values.append(value.to_string());
     }
 }
 
-StyleFunctionRule Parser::consume_a_function()
+NonnullRefPtr<StyleFunctionRule> Parser::consume_a_function()
 {
-    StyleFunctionRule function;
-    function.m_name = current_token().m_value.to_string();
+    NonnullRefPtr<StyleFunctionRule> function = create<StyleFunctionRule>(current_token().m_value.to_string());
 
     for (;;) {
         auto token = next_token();
@@ -522,7 +521,7 @@ StyleFunctionRule Parser::consume_a_function()
                 continue;
             }
         }
-        function.m_values.append(value.to_string());
+        function->m_values.append(value.to_string());
     }
 
     return function;
diff --git a/Userland/Libraries/LibWeb/CSS/Parser/Parser.h b/Userland/Libraries/LibWeb/CSS/Parser/Parser.h
index 1aadf31211..10e7d433ae 100644
--- a/Userland/Libraries/LibWeb/CSS/Parser/Parser.h
+++ b/Userland/Libraries/LibWeb/CSS/Parser/Parser.h
@@ -78,8 +78,8 @@ private:
     Optional<StyleDeclarationRule> consume_a_declaration(Vector<StyleComponentValueRule>);
     Optional<StyleDeclarationRule> consume_a_declaration();
     StyleComponentValueRule consume_a_component_value();
-    StyleBlockRule consume_a_simple_block();
-    StyleFunctionRule consume_a_function();
+    NonnullRefPtr<StyleBlockRule> consume_a_simple_block();
+    NonnullRefPtr<StyleFunctionRule> consume_a_function();
 
     Tokenizer m_tokenizer;
     Vector<Token> m_tokens;
diff --git a/Userland/Libraries/LibWeb/CSS/Parser/QualifiedStyleRule.h b/Userland/Libraries/LibWeb/CSS/Parser/QualifiedStyleRule.h
index da2f3c2e98..81e6b61533 100644
--- a/Userland/Libraries/LibWeb/CSS/Parser/QualifiedStyleRule.h
+++ b/Userland/Libraries/LibWeb/CSS/Parser/QualifiedStyleRule.h
@@ -8,6 +8,7 @@
 #pragma once
 
 #include <AK/Vector.h>
+#include <LibWeb/CSS/Parser/StyleBlockRule.h>
 #include <LibWeb/CSS/Parser/StyleComponentValueRule.h>
 
 namespace Web::CSS {
@@ -18,11 +19,15 @@ class QualifiedStyleRule {
 public:
     QualifiedStyleRule();
     ~QualifiedStyleRule();
+
+    Vector<StyleComponentValueRule> const& prelude() const { return m_prelude; }
+    StyleBlockRule const& block() const { return *m_block; }
+
     String to_string() const;
 
 private:
     Vector<StyleComponentValueRule> m_prelude;
-    StyleBlockRule m_block;
+    RefPtr<StyleBlockRule> m_block;
 };
 
 }
diff --git a/Userland/Libraries/LibWeb/CSS/Parser/StyleBlockRule.h b/Userland/Libraries/LibWeb/CSS/Parser/StyleBlockRule.h
index 84ba7d3ee6..a270351671 100644
--- a/Userland/Libraries/LibWeb/CSS/Parser/StyleBlockRule.h
+++ b/Userland/Libraries/LibWeb/CSS/Parser/StyleBlockRule.h
@@ -7,12 +7,13 @@
 
 #pragma once
 
+#include <AK/RefCounted.h>
 #include <AK/Vector.h>
 #include <LibWeb/CSS/Parser/Token.h>
 
 namespace Web::CSS {
 
-class StyleBlockRule {
+class StyleBlockRule : public RefCounted<StyleBlockRule> {
     friend class Parser;
 
 public:
@@ -31,5 +32,4 @@ private:
     Token m_token;
     Vector<String> m_values;
 };
-
 }
diff --git a/Userland/Libraries/LibWeb/CSS/Parser/StyleComponentValueRule.h b/Userland/Libraries/LibWeb/CSS/Parser/StyleComponentValueRule.h
index f03265dbef..1510bbcdb3 100644
--- a/Userland/Libraries/LibWeb/CSS/Parser/StyleComponentValueRule.h
+++ b/Userland/Libraries/LibWeb/CSS/Parser/StyleComponentValueRule.h
@@ -7,12 +7,15 @@
 
 #pragma once
 
-#include <LibWeb/CSS/Parser/StyleBlockRule.h>
-#include <LibWeb/CSS/Parser/StyleFunctionRule.h>
+#include <AK/NonnullRefPtr.h>
+#include <AK/RefPtr.h>
 #include <LibWeb/CSS/Parser/Token.h>
 
 namespace Web::CSS {
 
+class StyleBlockRule;
+class StyleFunctionRule;
+
 class StyleComponentValueRule {
     friend class Parser;
 
@@ -27,10 +30,18 @@ public:
     ~StyleComponentValueRule();
 
     bool is_block() const { return m_type == ComponentType::Block; }
-    StyleBlockRule const& block() const { return m_block; }
+    StyleBlockRule const& block() const
+    {
+        VERIFY(is_block());
+        return *m_block;
+    }
 
     bool is_function() const { return m_type == ComponentType::Function; }
-    StyleFunctionRule const& function() const { return m_function; }
+    StyleFunctionRule const& function() const
+    {
+        VERIFY(is_function());
+        return *m_function;
+    }
 
     bool is(Token::TokenType type) const
     {
@@ -44,7 +55,7 @@ public:
 private:
     ComponentType m_type;
     Token m_token;
-    StyleFunctionRule m_function;
-    StyleBlockRule m_block;
+    RefPtr<StyleFunctionRule> m_function;
+    RefPtr<StyleBlockRule> m_block;
 };
 }
diff --git a/Userland/Libraries/LibWeb/CSS/Parser/StyleFunctionRule.h b/Userland/Libraries/LibWeb/CSS/Parser/StyleFunctionRule.h
index 82de57c3e8..25c4bd2aa5 100644
--- a/Userland/Libraries/LibWeb/CSS/Parser/StyleFunctionRule.h
+++ b/Userland/Libraries/LibWeb/CSS/Parser/StyleFunctionRule.h
@@ -7,6 +7,7 @@
 
 #pragma once
 
+#include <AK/RefCounted.h>
 #include <AK/String.h>
 #include <AK/Vector.h>
 
@@ -14,11 +15,11 @@ namespace Web::CSS {
 
 class StyleComponentValueRule;
 
-class StyleFunctionRule {
+class StyleFunctionRule : public RefCounted<StyleFunctionRule> {
     friend class Parser;
 
 public:
-    StyleFunctionRule();
+    StyleFunctionRule(String name);
     ~StyleFunctionRule();
 
     String const& name() const { return m_name; }
@@ -38,5 +39,4 @@ private:
     String m_name;
     Vector<String> m_values;
 };
-
 }
diff --git a/Userland/Libraries/LibWeb/CSS/Parser/StyleRules.cpp b/Userland/Libraries/LibWeb/CSS/Parser/StyleRules.cpp
index e9457f9d63..3c21c712d0 100644
--- a/Userland/Libraries/LibWeb/CSS/Parser/StyleRules.cpp
+++ b/Userland/Libraries/LibWeb/CSS/Parser/StyleRules.cpp
@@ -45,7 +45,10 @@ StyleComponentValueRule::~StyleComponentValueRule() { }
 StyleDeclarationRule::StyleDeclarationRule() { }
 StyleDeclarationRule::~StyleDeclarationRule() { }
 
-StyleFunctionRule::StyleFunctionRule() { }
+StyleFunctionRule::StyleFunctionRule(String name)
+    : m_name(name)
+{
+}
 StyleFunctionRule::~StyleFunctionRule() { }
 
 template<class SeparatorType, class CollectionType>
@@ -106,7 +109,7 @@ String QualifiedStyleRule::to_string() const
     StringBuilder builder;
 
     append_with_to_string(builder, " ", m_prelude);
-    builder.append(m_block.to_string());
+    builder.append(m_block->to_string());
 
     return builder.to_string();
 }
@@ -131,10 +134,10 @@ String StyleComponentValueRule::to_string() const
         builder.append(m_token.to_string());
         break;
     case ComponentType::Function:
-        builder.append(m_function.to_string());
+        builder.append(m_function->to_string());
         break;
     case ComponentType::Block:
-        builder.append(m_block.to_string());
+        builder.append(m_block->to_string());
         break;
     }