[clang] [clang][Diagnostics] Highlight code snippets (PR #66514)

[Aaron Ballman via cfe-commits]

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Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/66514 at github.com>


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@@ -0,0 +1,185 @@
+//===-- CodeSnippetHighlighter.cpp - Code snippet highlighting --*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/CodeSnippetHighlighter.h"
+#include "clang/Basic/CharInfo.h"
+#include "clang/Basic/DiagnosticOptions.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Lex/PreprocessorOptions.h"
+#include "llvm/Support/raw_ostream.h"
+#include <chrono>
+
+using namespace clang;
+
+// Magenta is taken for 'warning'. Red is already 'error' and 'cyan'
+// is already taken for 'note'. Green is already used to underline
+// source ranges. White and black are bad because of the usual
+// terminal backgrounds. Which leaves us only with TWO options.
+static constexpr raw_ostream::Colors CommentColor = raw_ostream::YELLOW;
+static constexpr raw_ostream::Colors LiteralColor = raw_ostream::GREEN;
+static constexpr raw_ostream::Colors KeywordColor = raw_ostream::BLUE;
+/// Maximum size of file we still highlight.
+static constexpr size_t MaxBufferSize = 1024 * 1024; // 1MB.
+
+llvm::SmallVector<StyleRange> CodeSnippetHighlighter::highlightLine(
+    unsigned LineNumber, const Preprocessor *PP, const LangOptions &LangOpts,
+    FileID FID, const SourceManager &SM, const char *LineStart) {
+  std::chrono::steady_clock::time_point begin =
+      std::chrono::steady_clock::now();
+
+  if (!PP)
+    return {};
+
----------------
AaronBallman wrote:

Under what circumstances is `PP` null? Can we turn this into an assert? Or better yet, can we turn it into a const reference?

https://github.com/llvm/llvm-project/pull/66514