1 files changed, 259 insertions, 0 deletions
diff --git a/contrib/llvm-project/lldb/source/Plugins/Language/ClangCommon/ClangHighlighter.cpp b/contrib/llvm-project/lldb/source/Plugins/Language/ClangCommon/ClangHighlighter.cpp
new file mode 100644
index 000000000000..6e56e29f8c31
--- /dev/null
+++ b/contrib/llvm-project/lldb/source/Plugins/Language/ClangCommon/ClangHighlighter.cpp
@@ -0,0 +1,259 @@
+//===-- ClangHighlighter.cpp ----------------------------------------------===//
+//
+// 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 "ClangHighlighter.h"
+
+#include "lldb/Host/FileSystem.h"
+#include "lldb/Target/Language.h"
+#include "lldb/Utility/AnsiTerminal.h"
+#include "lldb/Utility/StreamString.h"
+
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Lex/Lexer.h"
+#include "llvm/ADT/StringSet.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include <optional>
+
+using namespace lldb_private;
+
+bool ClangHighlighter::isKeyword(llvm::StringRef token) const {
+  return keywords.contains(token);
+}
+
+ClangHighlighter::ClangHighlighter() {
+#define KEYWORD(X, N) keywords.insert(#X);
+#include "clang/Basic/TokenKinds.def"
+}
+
+/// Determines which style should be applied to the given token.
+/// \param highlighter
+///     The current highlighter that should use the style.
+/// \param token
+///     The current token.
+/// \param tok_str
+///     The string in the source code the token represents.
+/// \param options
+///     The style we use for coloring the source code.
+/// \param in_pp_directive
+///     If we are currently in a preprocessor directive. NOTE: This is
+///     passed by reference and will be updated if the current token starts
+///     or ends a preprocessor directive.
+/// \return
+///     The ColorStyle that should be applied to the token.
+static HighlightStyle::ColorStyle
+determineClangStyle(const ClangHighlighter &highlighter,
+                    const clang::Token &token, llvm::StringRef tok_str,
+                    const HighlightStyle &options, bool &in_pp_directive) {
+  using namespace clang;
+
+  if (token.is(tok::comment)) {
+    // If we were in a preprocessor directive before, we now left it.
+    in_pp_directive = false;
+    return options.comment;
+  } else if (in_pp_directive || token.getKind() == tok::hash) {
+    // Let's assume that the rest of the line is a PP directive.
+    in_pp_directive = true;
+    // Preprocessor directives are hard to match, so we have to hack this in.
+    return options.pp_directive;
+  } else if (tok::isStringLiteral(token.getKind()))
+    return options.string_literal;
+  else if (tok::isLiteral(token.getKind()))
+    return options.scalar_literal;
+  else if (highlighter.isKeyword(tok_str))
+    return options.keyword;
+  else
+    switch (token.getKind()) {
+    case tok::raw_identifier:
+    case tok::identifier:
+      return options.identifier;
+    case tok::l_brace:
+    case tok::r_brace:
+      return options.braces;
+    case tok::l_square:
+    case tok::r_square:
+      return options.square_brackets;
+    case tok::l_paren:
+    case tok::r_paren:
+      return options.parentheses;
+    case tok::comma:
+      return options.comma;
+    case tok::coloncolon:
+    case tok::colon:
+      return options.colon;
+
+    case tok::amp:
+    case tok::ampamp:
+    case tok::ampequal:
+    case tok::star:
+    case tok::starequal:
+    case tok::plus:
+    case tok::plusplus:
+    case tok::plusequal:
+    case tok::minus:
+    case tok::arrow:
+    case tok::minusminus:
+    case tok::minusequal:
+    case tok::tilde:
+    case tok::exclaim:
+    case tok::exclaimequal:
+    case tok::slash:
+    case tok::slashequal:
+    case tok::percent:
+    case tok::percentequal:
+    case tok::less:
+    case tok::lessless:
+    case tok::lessequal:
+    case tok::lesslessequal:
+    case tok::spaceship:
+    case tok::greater:
+    case tok::greatergreater:
+    case tok::greaterequal:
+    case tok::greatergreaterequal:
+    case tok::caret:
+    case tok::caretequal:
+    case tok::pipe:
+    case tok::pipepipe:
+    case tok::pipeequal:
+    case tok::question:
+    case tok::equal:
+    case tok::equalequal:
+      return options.operators;
+    default:
+      break;
+    }
+  return HighlightStyle::ColorStyle();
+}
+
+void ClangHighlighter::Highlight(const HighlightStyle &options,
+                                 llvm::StringRef line,
+                                 std::optional<size_t> cursor_pos,
+                                 llvm::StringRef previous_lines,
+                                 Stream &result) const {
+  using namespace clang;
+
+  FileSystemOptions file_opts;
+  FileManager file_mgr(file_opts,
+                       FileSystem::Instance().GetVirtualFileSystem());
+
+  // The line might end in a backslash which would cause Clang to drop the
+  // backslash and the terminating new line. This makes sense when parsing C++,
+  // but when highlighting we care about preserving the backslash/newline. To
+  // not lose this information we remove the new line here so that Clang knows
+  // this is just a single line we are highlighting. We add back the newline
+  // after tokenizing.
+  llvm::StringRef line_ending = "";
+  // There are a few legal line endings Clang recognizes and we need to
+  // temporarily remove from the string.
+  if (line.consume_back("\r\n"))
+    line_ending = "\r\n";
+  else if (line.consume_back("\n"))
+    line_ending = "\n";
+  else if (line.consume_back("\r"))
+    line_ending = "\r";
+
+  unsigned line_number = previous_lines.count('\n') + 1U;
+
+  // Let's build the actual source code Clang needs and setup some utility
+  // objects.
+  std::string full_source = previous_lines.str() + line.str();
+  llvm::IntrusiveRefCntPtr<DiagnosticIDs> diag_ids(new DiagnosticIDs());
+  llvm::IntrusiveRefCntPtr<DiagnosticOptions> diags_opts(
+      new DiagnosticOptions());
+  DiagnosticsEngine diags(diag_ids, diags_opts);
+  clang::SourceManager SM(diags, file_mgr);
+  auto buf = llvm::MemoryBuffer::getMemBuffer(full_source);
+
+  FileID FID = SM.createFileID(buf->getMemBufferRef());
+
+  // Let's just enable the latest ObjC and C++ which should get most tokens
+  // right.
+  LangOptions Opts;
+  Opts.ObjC = true;
+  // FIXME: This should probably set CPlusPlus, CPlusPlus11, ... too
+  Opts.CPlusPlus17 = true;
+  Opts.LineComment = true;
+
+  Lexer lex(FID, buf->getMemBufferRef(), SM, Opts);
+  // The lexer should keep whitespace around.
+  lex.SetKeepWhitespaceMode(true);
+
+  // Keeps track if we have entered a PP directive.
+  bool in_pp_directive = false;
+
+  // True once we actually lexed the user provided line.
+  bool found_user_line = false;
+
+  // True if we already highlighted the token under the cursor, false otherwise.
+  bool highlighted_cursor = false;
+  Token token;
+  bool exit = false;
+  while (!exit) {
+    // Returns true if this is the last token we get from the lexer.
+    exit = lex.LexFromRawLexer(token);
+
+    bool invalid = false;
+    unsigned current_line_number =
+        SM.getSpellingLineNumber(token.getLocation(), &invalid);
+    if (current_line_number != line_number)
+      continue;
+    found_user_line = true;
+
+    // We don't need to print any tokens without a spelling line number.
+    if (invalid)
+      continue;
+
+    // Same as above but with the column number.
+    invalid = false;
+    unsigned start = SM.getSpellingColumnNumber(token.getLocation(), &invalid);
+    if (invalid)
+      continue;
+    // Column numbers start at 1, but indexes in our string start at 0.
+    --start;
+
+    // Annotations don't have a length, so let's skip them.
+    if (token.isAnnotation())
+      continue;
+
+    // Extract the token string from our source code.
+    llvm::StringRef tok_str = line.substr(start, token.getLength());
+
+    // If the token is just an empty string, we can skip all the work below.
+    if (tok_str.empty())
+      continue;
+
+    // If the cursor is inside this token, we have to apply the 'selected'
+    // highlight style before applying the actual token color.
+    llvm::StringRef to_print = tok_str;
+    StreamString storage;
+    auto end = start + token.getLength();
+    if (cursor_pos && end > *cursor_pos && !highlighted_cursor) {
+      highlighted_cursor = true;
+      options.selected.Apply(storage, tok_str);
+      to_print = storage.GetString();
+    }
+
+    // See how we are supposed to highlight this token.
+    HighlightStyle::ColorStyle color =
+        determineClangStyle(*this, token, tok_str, options, in_pp_directive);
+
+    color.Apply(result, to_print);
+  }
+
+  // Add the line ending we trimmed before tokenizing.
+  result << line_ending;
+
+  // If we went over the whole file but couldn't find our own file, then
+  // somehow our setup was wrong. When we're in release mode we just give the
+  // user the normal line and pretend we don't know how to highlight it. In
+  // debug mode we bail out with an assert as this should never happen.
+  if (!found_user_line) {
+    result << line;
+    assert(false && "We couldn't find the user line in the input file?");
+  }
+}