[clang] [clang-format] Don't skip stringizing when determining brace kind (PR #73886)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-format

Author: Emilia Kond (rymiel)

<details>
<summary>Changes</summary>

PR #<!-- -->69473 introduced skipping PP directives when determining the brace kind of an lbrace. However, it did so by skipping to the end of the line when encountering a hash character. This means it also skipped to the end of line when encountering a macro stringizing operator, which, unlike PP directives, don't have effect until the end of line.

This led to cases where the rbrace could be completely skipped if it was on the same line as a stringizing operator.

This patch skips hash characters if we're already in a PP directive, as you can't define a macro inside of a macro

Fixes https://github.com/llvm/llvm-project/issues/72662

---
Full diff: https://github.com/llvm/llvm-project/pull/73886.diff


2 Files Affected:

- (modified) clang/lib/Format/UnwrappedLineParser.cpp (+1-1) 
- (modified) clang/unittests/Format/TokenAnnotatorTest.cpp (+16) 


``````````diff
diff --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp
index a5a4419b98239e6..5f574dfeafc874b 100644
--- a/clang/lib/Format/UnwrappedLineParser.cpp
+++ b/clang/lib/Format/UnwrappedLineParser.cpp
@@ -496,7 +496,7 @@ void UnwrappedLineParser::calculateBraceTypes(bool ExpectClassBody) {
     do {
       NextTok = Tokens->getNextToken();
     } while (NextTok->is(tok::comment));
-    while (NextTok->is(tok::hash)) {
+    while (NextTok->is(tok::hash) && !Line->InPPDirective) {
       NextTok = Tokens->getNextToken();
       do {
         NextTok = Tokens->getNextToken();
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index bc734573ce0cb4d..8ad6a585d004593 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -1851,6 +1851,22 @@ TEST_F(TokenAnnotatorTest, UnderstandsTrailingReturnArrow) {
   EXPECT_TOKEN(Tokens[13], tok::arrow, TT_Unknown);
 }
 
+TEST_F(TokenAnnotatorTest, UnderstandHashInMacro) {
+  auto Tokens = annotate("#define Foo(Bar) \\\n"
+                         "  { \\\n"
+                         "    #Bar \\\n"
+                         "  }\n");
+  ASSERT_EQ(Tokens.size(), 11u) << Tokens;
+  EXPECT_BRACE_KIND(Tokens[6], BK_Block);
+  EXPECT_BRACE_KIND(Tokens[9], BK_Block);
+
+  Tokens = annotate("#define Foo(Bar) \\\n"
+                    "  { #Bar }\n");
+  ASSERT_EQ(Tokens.size(), 11u) << Tokens;
+  EXPECT_BRACE_KIND(Tokens[6], BK_Block);
+  EXPECT_BRACE_KIND(Tokens[9], BK_Block);
+}
+
 TEST_F(TokenAnnotatorTest, UnderstandsAttributeMacros) {
   // '__attribute__' has special handling.
   auto Tokens = annotate("__attribute__(X) void Foo(void);");

``````````

</details>


https://github.com/llvm/llvm-project/pull/73886