[clang] [clang][Diagnostics] Highlight code snippets (PR #66514)
Timm Baeder via cfe-commits
cfe-commits at lists.llvm.org
Tue Nov 7 21:08:06 PST 2023
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>,
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>,
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>,
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>,
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>,
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>,
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>,
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>,
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>,
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>,
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>,
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>,
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>,
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>,
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>,
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>,
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>,
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>,
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>,
Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>
Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/66514 at github.com>
================
@@ -0,0 +1,187 @@
+//===-- 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/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;
+
+static constexpr raw_ostream::Colors CommentColor = raw_ostream::GREEN;
+static constexpr raw_ostream::Colors LiteralColor = raw_ostream::CYAN;
+static constexpr raw_ostream::Colors KeywordColor = raw_ostream::BLUE;
+
+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 {};
+
+ // Might cause emission of another diagnostic.
+ if (PP->getIdentifierTable().getExternalIdentifierLookup())
+ return {};
+
+ size_t NTokens = 0;
+ // Classify the given token and append it to the given vector.
+ auto appendStyle = [PP, &LangOpts](llvm::SmallVector<StyleRange> &Vec,
+ const Token &T, unsigned Start,
+ unsigned Length) -> void {
+ if (T.is(tok::raw_identifier)) {
+ StringRef RawIdent = T.getRawIdentifier();
+ // Special case true/false/nullptr literals, since they will otherwise be
+ // treated as keywords.
+ if (RawIdent == "true" || RawIdent == "false" || RawIdent == "nullptr") {
+ Vec.push_back(StyleRange{Start, Start + Length, LiteralColor});
+ } else {
+ const IdentifierInfo *II = PP->getIdentifierInfo(RawIdent);
+ assert(II);
+ if (II->isKeyword(LangOpts))
+ Vec.push_back(StyleRange{Start, Start + Length, KeywordColor});
+ }
+ } else if (tok::isLiteral(T.getKind())) {
+ Vec.push_back(StyleRange{Start, Start + Length, LiteralColor});
+ } else {
+ assert(T.is(tok::comment));
+ Vec.push_back(StyleRange{Start, Start + Length, CommentColor});
+ }
+ };
+
+ // Figure out where to start lexing from.
+ auto Buff = SM.getBufferOrNone(FID);
+ assert(Buff);
+ Lexer L = Lexer(FID, *Buff, SM, LangOpts);
+ L.SetKeepWhitespaceMode(true);
+
+ // Seek to the last save point before the start of the line.
+ if (const char *Save = PP->getSaveFor(LineStart);
+ Buff->getBufferStart() <= Save && Save < Buff->getBufferEnd()) {
+ size_t Offset = Save - Buff->getBufferStart();
+ assert(Save >= Buff->getBufferStart());
+ assert(Save <= Buff->getBufferEnd());
+
+ L.seek(Offset, /*IsAtStartOfLine=*/true);
+ }
+
+ llvm::SmallVector<StyleRange> LineRanges;
+ bool Stop = false;
+ while (!Stop) {
+ ++NTokens;
+ Token T;
+ Stop = L.LexFromRawLexer(T);
+ if (T.is(tok::unknown))
+ continue;
+
+ // We are only interested in identifiers, literals and comments.
+ if (!T.is(tok::raw_identifier) && !T.is(tok::comment) &&
+ !tok::isLiteral(T.getKind()))
+ continue;
+
+ bool Invalid = false;
+ unsigned EndLine = SM.getSpellingLineNumber(T.getEndLoc(), &Invalid) - 1;
+ if (Invalid)
+ continue;
+
+ if (EndLine < LineNumber)
+ continue;
+ unsigned StartLine =
+ SM.getSpellingLineNumber(T.getLocation(), &Invalid) - 1;
+ if (Invalid)
+ continue;
+ if (StartLine > LineNumber)
+ break;
+
+ // Must have an intersection at this point
+ assert(StartLine <= LineNumber && EndLine >= LineNumber);
+
+ unsigned StartCol =
+ SM.getSpellingColumnNumber(T.getLocation(), &Invalid) - 1;
+ if (Invalid)
+ continue;
+
+ // Simple tokens.
+ if (StartLine == EndLine) {
+ appendStyle(LineRanges, T, StartCol, T.getLength());
+ continue;
+ }
+ unsigned NumLines = EndLine - StartLine;
+ assert(NumLines >= 1);
+
+ // For tokens that span multiple lines (think multiline comments), we
+ // divide them into multiple StyleRanges.
+ unsigned EndCol = SM.getSpellingColumnNumber(T.getEndLoc(), &Invalid) - 1;
+ if (Invalid)
+ continue;
+
+ std::string Spelling = Lexer::getSpelling(T, SM, LangOpts);
+
+ unsigned L = 0;
+ unsigned LineLength = 0;
+ for (unsigned I = 0; I <= Spelling.size(); ++I) {
+ // This line is done.
+ if (Spelling[I] == '\n' || Spelling[I] == '\r' || I == Spelling.size()) {
+ if (StartLine + L == LineNumber) {
+ if (L == 0) // First line
+ appendStyle(LineRanges, T, StartCol, LineLength);
+ else if (L == NumLines) // Last line
+ appendStyle(LineRanges, T, 0, EndCol);
+ else
+ appendStyle(LineRanges, T, 0, LineLength);
+
+ // We only do one line, so we're done.
+ break;
+ }
+ ++L;
+ LineLength = 0;
+ continue;
+ }
+ ++LineLength;
+ }
+ }
+
+#if 0
+ llvm::errs() << "--\nLine Style info: \n";
+ //int I = 0;
+ //for (std::vector<StyleRange> &Line : Lines) {
+ //llvm::errs() << I << ": ";
+ for (const auto &R : LineRanges) {
+ llvm::errs() << "{" << R.Start << ", " << R.End << "}, ";
+ }
+ llvm::errs() << "\n";
+
+ //++I;
+ //}
+#endif
+
+#if 0
+ std::chrono::steady_clock::time_point end = std::chrono::steady_clock::now();
+ llvm::errs() << "Lexed " << NTokens << " Tokens\n";
+ llvm::errs() << "That took "
+ << std::chrono::duration_cast<std::chrono::microseconds>(end -
+ begin)
+ .count()
+ << " microseconds\n";
+ llvm::errs() << "That took "
+ << std::chrono::duration_cast<std::chrono::milliseconds>(end -
+ begin)
+ .count()
+ << " milliseconds\n";
+ llvm::errs()
+ << "That took "
+ << std::chrono::duration_cast<std::chrono::seconds>(end - begin).count()
+ << " seconds\n";
+#endif
----------------
tbaederr wrote:
Yeah, I'll remove it once we've decided what to do about performance, i.e. are we now going to add checkpoints to the lexer or only deciding whether to highlight snippets based on file size? (I also want to change the `SnippetHighlighter` API based on that, i.e. generate the highlighting info for all requested lines instead of just one).
https://github.com/llvm/llvm-project/pull/66514
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