LibCMake+LibSyntax: Add a CMake syntax highlighter

Userland/Libraries/LibCMake/CMakeLists.txt

@@ -1,5 +1,6 @@
 set(SOURCES
     Lexer.cpp
+    SyntaxHighlighter.cpp
     Token.cpp
 )
 

Userland/Libraries/LibCMake/SyntaxHighlighter.cpp

@@ -0,0 +1,112 @@
+/*
+ * Copyright (c) 2023, Sam Atkins <atkinssj@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "SyntaxHighlighter.h"
+#include <LibCMake/Lexer.h>
+#include <LibCMake/Token.h>
+
+namespace CMake {
+
+static Syntax::TextStyle style_for_token_type(Gfx::Palette const& palette, Token::Type type)
+{
+    switch (type) {
+    case Token::Type::BracketComment:
+    case Token::Type::LineComment:
+        return { palette.syntax_comment() };
+    case Token::Type::Identifier:
+        return { palette.syntax_function() };
+    case Token::Type::ControlKeyword:
+        return { palette.syntax_control_keyword() };
+    case Token::Type::OpenParen:
+    case Token::Type::CloseParen:
+        return { palette.syntax_punctuation() };
+    case Token::Type::BracketArgument:
+        return { palette.syntax_parameter() };
+    case Token::Type::QuotedArgument:
+        return { palette.syntax_string() };
+    case Token::Type::UnquotedArgument:
+        return { palette.syntax_parameter() };
+    case Token::Type::Garbage:
+        return { palette.red() };
+    case Token::Type::VariableReference:
+        // This is a bit arbitrary, since we don't have a color specifically for this.
+        return { palette.syntax_preprocessor_value() };
+    default:
+        return { palette.base_text() };
+    }
+}
+
+bool SyntaxHighlighter::is_identifier(u64 token_type) const
+{
+    auto cmake_token = static_cast<Token::Type>(token_type);
+    return cmake_token == Token::Type::Identifier;
+}
+
+void SyntaxHighlighter::rehighlight(Gfx::Palette const& palette)
+{
+    auto text = m_client->get_text();
+    auto tokens = Lexer::lex(text).release_value_but_fixme_should_propagate_errors();
+
+    Vector<GUI::TextDocumentSpan> spans;
+    auto highlight_span = [&](Token::Type type, Position const& start, Position const& end) {
+        GUI::TextDocumentSpan span;
+        span.range.set_start({ start.line, start.column });
+        span.range.set_end({ end.line, end.column });
+        if (!span.range.is_valid())
+            return;
+
+        auto style = style_for_token_type(palette, type);
+        span.attributes.color = style.color;
+        span.attributes.bold = style.bold;
+        if (type == Token::Type::Garbage) {
+            span.attributes.underline = true;
+            span.attributes.underline_color = palette.red();
+            span.attributes.underline_style = Gfx::TextAttributes::UnderlineStyle::Wavy;
+        }
+        span.is_skippable = false;
+        span.data = static_cast<u64>(type);
+        spans.append(move(span));
+    };
+
+    for (auto const& token : tokens) {
+        if (token.type == Token::Type::QuotedArgument || token.type == Token::Type::UnquotedArgument) {
+            // Alternately highlight the regular/variable-reference parts.
+            // 0-length ranges are caught in highlight_span() so we don't have to worry about them.
+            Position previous_position = token.start;
+            for (auto const& reference : token.variable_references) {
+                highlight_span(token.type, previous_position, reference.start);
+                highlight_span(Token::Type::VariableReference, reference.start, reference.end);
+                previous_position = reference.end;
+            }
+            highlight_span(token.type, previous_position, token.end);
+            continue;
+        }
+
+        highlight_span(token.type, token.start, token.end);
+    }
+    m_client->do_set_spans(move(spans));
+
+    m_has_brace_buddies = false;
+    highlight_matching_token_pair();
+
+    m_client->do_update();
+}
+
+Vector<SyntaxHighlighter::MatchingTokenPair> SyntaxHighlighter::matching_token_pairs_impl() const
+{
+    static Vector<MatchingTokenPair> pairs;
+    if (pairs.is_empty()) {
+        pairs.append({ static_cast<u64>(Token::Type::OpenParen), static_cast<u64>(Token::Type::CloseParen) });
+    }
+    return pairs;
+}
+
+bool SyntaxHighlighter::token_types_equal(u64 token1, u64 token2) const
+{
+    return static_cast<Token::Type>(token1) == static_cast<Token::Type>(token2);
+}
+
+}

Userland/Libraries/LibCMake/SyntaxHighlighter.h

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2023, Sam Atkins <atkinssj@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibSyntax/Highlighter.h>
+
+namespace CMake {
+
+class SyntaxHighlighter final : public Syntax::Highlighter {
+public:
+    SyntaxHighlighter() = default;
+    virtual ~SyntaxHighlighter() override = default;
+
+    virtual bool is_identifier(u64) const override;
+
+    virtual Syntax::Language language() const override { return Syntax::Language::CMake; }
+    virtual Optional<StringView> comment_prefix() const override { return "#"sv; }
+    virtual Optional<StringView> comment_suffix() const override { return {}; }
+    virtual void rehighlight(Palette const&) override;
+
+protected:
+    virtual Vector<MatchingTokenPair> matching_token_pairs_impl() const override;
+    virtual bool token_types_equal(u64, u64) const override;
+};
+
+}

Userland/Libraries/LibSyntax/Highlighter.cpp

@@ -141,6 +141,8 @@ void Highlighter::register_nested_token_pairs(Vector<MatchingTokenPair> pairs)
 StringView language_to_string(Language language)
 {
     switch (language) {
+    case Language::CMake:
+        return "CMake"sv;
     case Language::Cpp:
         return "C++"sv;
     case Language::CSS:
@@ -168,6 +170,8 @@ StringView language_to_string(Language language)
 StringView common_language_extension(Language language)
 {
     switch (language) {
+    case Language::CMake:
+        return "cmake"sv;
     case Language::Cpp:
         return "cpp"sv;
     case Language::CSS:

Userland/Libraries/LibSyntax/Highlighter.h

@@ -15,6 +15,7 @@
 namespace Syntax {
 
 enum class Language {
+    CMake,
     Cpp,
     CSS,
     GitCommit,