[clang] [clang-format] Separate License text and include blocks (PR #77918)

[Björn Schäpers via cfe-commits]

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@@ -0,0 +1,70 @@
+//===--- TopLevelCommentSeparator.cpp ---------------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file implements TopLevelCommentSeparator, a TokenAnalyzer that inserts
+/// new lines or removes empty lines after the top level comment (i.e. comment
+/// block at the top of the source file), usually license text or documentation.
+///
+//===----------------------------------------------------------------------===//
+
+#include "TopLevelCommentSeparator.h"
+#define DEBUG_TYPE "top-level-comment-separator"
+
+namespace clang {
+namespace format {
+std::pair<tooling::Replacements, unsigned> TopLevelCommentSeparator::analyze(
+    TokenAnnotator &Annotator, SmallVectorImpl<AnnotatedLine *> &AnnotatedLines,
+    FormatTokenLexer &Tokens) {
+  assert(Style.EmptyLinesAfterTopLevelComment.has_value());
+  AffectedRangeMgr.computeAffectedLines(AnnotatedLines);
+  tooling::Replacements Result;
+  separateTopLevelComment(AnnotatedLines, Result, Tokens);
+  return {Result, 0};
+}
+
+void TopLevelCommentSeparator::separateTopLevelComment(
+    SmallVectorImpl<AnnotatedLine *> &Lines, tooling::Replacements &Result,
+    FormatTokenLexer &Tokens) {
+  unsigned NewlineCount = std::min(Style.MaxEmptyLinesToKeep,
+                                   *Style.EmptyLinesAfterTopLevelComment) +
+                          1;
+  WhitespaceManager Whitespaces(
+      Env.getSourceManager(), Style,
+      Style.LineEnding > FormatStyle::LE_CRLF
+          ? WhitespaceManager::inputUsesCRLF(
+                Env.getSourceManager().getBufferData(Env.getFileID()),
+                Style.LineEnding == FormatStyle::LE_DeriveCRLF)
+          : Style.LineEnding == FormatStyle::LE_CRLF);
+
+  bool InTopLevelComment = false;
+  for (unsigned I = 0; I < Lines.size(); ++I) {
+    const auto &CurrentLine = Lines[I];
+    if (CurrentLine->isComment()) {
+      InTopLevelComment = true;
+    } else if (InTopLevelComment) {
+      // Do not handle EOF newlines.
+      if (!CurrentLine->First->is(tok::eof) && CurrentLine->Affected) {
+        Whitespaces.replaceWhitespace(*CurrentLine->First, NewlineCount,
+                                      CurrentLine->First->OriginalColumn,
+                                      CurrentLine->First->OriginalColumn);
+      }
+      break;
+    }
----------------
HazardyKnusperkeks wrote:

Another one
```c++
int foo() {
  // Comment
  return 5;
}
```

https://github.com/llvm/llvm-project/pull/77918