[clang] [clang-format] Fix a bug in aligning comments above PPDirective (PR #72791)

[Owen Pan via cfe-commits]

https://github.com/owenca created https://github.com/llvm/llvm-project/pull/72791

Fixed #72785.

>From 0aadd3c1e458f1137c4d45bc14dfae7db9b0446f Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Sun, 19 Nov 2023 03:41:58 -0800
Subject: [PATCH] [clang-format] Fix a bug in aligning comments above
 PPDirective

Fixed #72785.
---
 clang/lib/Format/TokenAnnotator.cpp           |  4 ++--
 clang/unittests/Format/FormatTestComments.cpp | 11 +++++++++++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index 1d376cd8b5794dd..d1b3045ab63a87a 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -3123,8 +3123,8 @@ void TokenAnnotator::setCommentLineLevels(
 
     // If the comment is currently aligned with the line immediately following
     // it, that's probably intentional and we should keep it.
-    if (NextNonCommentLine && !NextNonCommentLine->First->Finalized &&
-        Line->isComment() && NextNonCommentLine->First->NewlinesBefore <= 1 &&
+    if (NextNonCommentLine && NextNonCommentLine->First->NewlinesBefore < 2 &&
+        Line->isComment() && !isClangFormatOff(Line->First->TokenText) &&
         NextNonCommentLine->First->OriginalColumn ==
             Line->First->OriginalColumn) {
       const bool PPDirectiveOrImportStmt =
diff --git a/clang/unittests/Format/FormatTestComments.cpp b/clang/unittests/Format/FormatTestComments.cpp
index 967ffa32db79c75..9770d5090703c77 100644
--- a/clang/unittests/Format/FormatTestComments.cpp
+++ b/clang/unittests/Format/FormatTestComments.cpp
@@ -1069,6 +1069,17 @@ TEST_F(FormatTestComments, KeepsLevelOfCommentBeforePPDirective) {
                        "  // clang-format on\n"
                        "}");
   verifyNoChange(Code);
+
+  auto Style = getLLVMStyle();
+  Style.IndentPPDirectives = FormatStyle::PPDIS_BeforeHash;
+  verifyFormat("#ifdef FOO\n"
+               "  // Foo\n"
+               "  #define Foo foo\n"
+               "#else\n"
+               "  // Bar\n"
+               "  #define Bar bar\n"
+               "#endif",
+               Style);
 }
 
 TEST_F(FormatTestComments, SplitsLongLinesInComments) {