[clang] [clang-format] Add TT_AfterPPDirective for better annotation (PR #121622)

[Owen Pan via cfe-commits]

https://github.com/owenca created https://github.com/llvm/llvm-project/pull/121622

For now, we only need to annotate the token after #error or #warning.

Fixes #117706.

>From 9daceef16b0a387257713d1a379782598d537fd9 Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Tue, 3 Dec 2024 01:40:56 -0800
Subject: [PATCH] [clang-format] Add TT_AfterPPDirective for better annotation

For now, we only need to annotate the token after #error or #warning.

Fixes #117706.
---
 clang/lib/Format/FormatToken.h                | 1 +
 clang/lib/Format/TokenAnnotator.cpp           | 4 ++++
 clang/lib/Format/UnwrappedLineParser.cpp      | 9 +++++++--
 clang/unittests/Format/TokenAnnotatorTest.cpp | 7 +++++++
 4 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Format/FormatToken.h b/clang/lib/Format/FormatToken.h
index 8917049cefb865..0fd3a49c71f9d1 100644
--- a/clang/lib/Format/FormatToken.h
+++ b/clang/lib/Format/FormatToken.h
@@ -25,6 +25,7 @@ namespace clang {
 namespace format {
 
 #define LIST_TOKEN_TYPES                                                       \
+  TYPE(AfterPPDirective)                                                       \
   TYPE(ArrayInitializerLSquare)                                                \
   TYPE(ArraySubscriptLSquare)                                                  \
   TYPE(AttributeColon)                                                         \
diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index b0f570966a63f3..fad375733ef845 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -4941,6 +4941,10 @@ bool TokenAnnotator::spaceRequiredBefore(const AnnotatedLine &Line,
         Right.is(TT_ModulePartitionColon)) {
       return true;
     }
+
+    if (Right.is(TT_AfterPPDirective))
+      return true;
+
     // No space between import foo:bar but keep a space between import :bar;
     if (Left.is(tok::identifier) && Right.is(TT_ModulePartitionColon))
       return false;
diff --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp
index 654148a161bd7f..724b99a0bc7ab7 100644
--- a/clang/lib/Format/UnwrappedLineParser.cpp
+++ b/clang/lib/Format/UnwrappedLineParser.cpp
@@ -1032,6 +1032,12 @@ void UnwrappedLineParser::parsePPDirective() {
   case tok::pp_pragma:
     parsePPPragma();
     break;
+  case tok::pp_error:
+  case tok::pp_warning:
+    nextToken();
+    if (!eof() && Style.isCpp())
+      FormatTok->setFinalizedType(TT_AfterPPDirective);
+    [[fallthrough]];
   default:
     parsePPUnknown();
     break;
@@ -1211,9 +1217,8 @@ void UnwrappedLineParser::parsePPPragma() {
 }
 
 void UnwrappedLineParser::parsePPUnknown() {
-  do {
+  while (!eof())
     nextToken();
-  } while (!eof());
   if (Style.IndentPPDirectives != FormatStyle::PPDIS_None)
     Line->Level += PPBranchLevel + 1;
   addUnwrappedLine();
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index d61b9adf4f58c6..875feff3d54202 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -3635,6 +3635,13 @@ TEST_F(TokenAnnotatorTest, SwitchInMacroArgument) {
   EXPECT_TOKEN(Tokens[9], tok::l_brace, TT_FunctionLBrace);
 }
 
+TEST_F(TokenAnnotatorTest, AfterPPDirective) {
+  auto Tokens = annotate("#error -- My error message");
+
+  ASSERT_EQ(Tokens.size(), 7u) << Tokens;
+  EXPECT_TOKEN(Tokens[2], tok::minusminus, TT_AfterPPDirective);
+}
+
 } // namespace
 } // namespace format
 } // namespace clang