[clang] [clang-format] Fix handling of C-Style variable definition of a struct (PR #76344)

[via cfe-commits]

https://github.com/XDeme updated https://github.com/llvm/llvm-project/pull/76344

>From a55c720f344645bdad3838aaa39b136c8b8ee6dc Mon Sep 17 00:00:00 2001
From: XDeme <fernando.tagawa.gamail.com at gmail.com>
Date: Sun, 24 Dec 2023 20:18:02 -0300
Subject: [PATCH 1/2] [clang-format] Fix handling of C-Style variable
 definition of a struct

---
 clang/lib/Format/UnwrappedLineParser.cpp      | 8 ++++++++
 clang/unittests/Format/FormatTest.cpp         | 1 +
 clang/unittests/Format/TokenAnnotatorTest.cpp | 6 ++++++
 3 files changed, 15 insertions(+)

diff --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp
index 684609747a5513..9cacb0d175adae 100644
--- a/clang/lib/Format/UnwrappedLineParser.cpp
+++ b/clang/lib/Format/UnwrappedLineParser.cpp
@@ -3873,6 +3873,7 @@ void UnwrappedLineParser::parseRecord(bool ParseAsExpr) {
   const FormatToken &InitialToken = *FormatTok;
   nextToken();
 
+  int NonMacroIdentifierCount = 0;
   // The actual identifier can be a nested name specifier, and in macros
   // it is often token-pasted.
   // An [[attribute]] can be before the identifier.
@@ -3898,6 +3899,8 @@ void UnwrappedLineParser::parseRecord(bool ParseAsExpr) {
         FormatTok->is(tok::identifier) &&
         FormatTok->TokenText != FormatTok->TokenText.upper();
     nextToken();
+    if (IsNonMacroIdentifier)
+      ++NonMacroIdentifierCount;
     // We can have macros in between 'class' and the class name.
     if (!IsNonMacroIdentifier && FormatTok->is(tok::l_paren))
       parseParens();
@@ -3960,6 +3963,11 @@ void UnwrappedLineParser::parseRecord(bool ParseAsExpr) {
     }
   };
   if (FormatTok->is(tok::l_brace)) {
+    // Handles C-Style variable declaration of a struct
+    if (Style.isCpp() && NonMacroIdentifierCount == 2) {
+      parseBracedList();
+      return;
+    }
     auto [OpenBraceType, ClosingBraceType] = GetBraceTypes(InitialToken);
     FormatTok->setFinalizedType(OpenBraceType);
     if (ParseAsExpr) {
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 762fc8254bdfc9..d37d1f58b51a4a 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -14548,6 +14548,7 @@ TEST_F(FormatTest, UnderstandContextOfRecordTypeKeywords) {
   verifyFormat("struct foo f() {}\nint n;");
   verifyFormat("class foo f() {}\nint n;");
   verifyFormat("union foo f() {}\nint n;");
+  verifyFormat("struct MACRO foo f{};");
 
   // Templates.
   verifyFormat("template <class X> void f() {}\nint n;");
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index 2cafc0438ffb46..568574bf73a872 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -503,6 +503,12 @@ TEST_F(TokenAnnotatorTest, UnderstandsVariables) {
       annotate("inline bool var = is_integral_v<int> && is_signed_v<int>;");
   EXPECT_EQ(Tokens.size(), 15u) << Tokens;
   EXPECT_TOKEN(Tokens[8], tok::ampamp, TT_BinaryOperator);
+
+  Tokens = annotate("struct Foo f{};");
+  EXPECT_EQ(Tokens.size(), 7u) << Tokens;
+  EXPECT_TOKEN(Tokens[1], tok::identifier, TT_Unknown);
+  EXPECT_TOKEN(Tokens[2], tok::identifier, TT_StartOfName);
+  EXPECT_TOKEN(Tokens[3], tok::l_brace, TT_Unknown);
 }
 
 TEST_F(TokenAnnotatorTest, UnderstandsVariableTemplates) {

>From 9e2e88495e86f040aeca2a0f0bc69bff3e6986e4 Mon Sep 17 00:00:00 2001
From: XDeme <fernando.tagawa.gamail.com at gmail.com>
Date: Tue, 26 Dec 2023 14:11:09 -0300
Subject: [PATCH 2/2] Added support for templated structs

---
 clang/lib/Format/UnwrappedLineParser.cpp      | 13 +++++++++++++
 clang/unittests/Format/FormatTest.cpp         |  3 ++-
 clang/unittests/Format/TokenAnnotatorTest.cpp |  6 ++++++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp
index 9cacb0d175adae..e79eefd530451b 100644
--- a/clang/lib/Format/UnwrappedLineParser.cpp
+++ b/clang/lib/Format/UnwrappedLineParser.cpp
@@ -3917,6 +3917,8 @@ void UnwrappedLineParser::parseRecord(bool ParseAsExpr) {
   // (this would still leave us with an ambiguity between template function
   // and class declarations).
   if (FormatTok->isOneOf(tok::colon, tok::less)) {
+    int AngleNestingLevel = 0;
+    bool ColonFound = false;
     do {
       if (FormatTok->is(tok::l_brace)) {
         calculateBraceTypes(/*ExpectClassBody=*/true);
@@ -3944,6 +3946,17 @@ void UnwrappedLineParser::parseRecord(bool ParseAsExpr) {
         parseCSharpGenericTypeConstraint();
         break;
       }
+      // Do not count identifiers inside a template angle brackets
+      if(FormatTok->is(tok::colon))
+        ColonFound = true;
+      if (FormatTok->is(tok::less))
+        ++AngleNestingLevel;
+      else if (FormatTok->is(tok::greater))
+        --AngleNestingLevel;
+      if (AngleNestingLevel == 0 && !ColonFound && FormatTok->is(tok::identifier) &&
+          FormatTok->TokenText != FormatTok->TokenText.upper()) {
+        ++NonMacroIdentifierCount;
+      }
       nextToken();
     } while (!eof());
   }
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index d37d1f58b51a4a..04505e25b00c03 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -14543,12 +14543,13 @@ TEST_F(FormatTest, UnderstandContextOfRecordTypeKeywords) {
   verifyFormat("struct foo a = {bar};\nint n;");
   verifyFormat("class foo a = {bar};\nint n;");
   verifyFormat("union foo a = {bar};\nint n;");
+  verifyFormat("struct MACRO foo f{};");
+  verifyFormat("struct MACRO foo<int> f{};");
 
   // Elaborate types inside function definitions.
   verifyFormat("struct foo f() {}\nint n;");
   verifyFormat("class foo f() {}\nint n;");
   verifyFormat("union foo f() {}\nint n;");
-  verifyFormat("struct MACRO foo f{};");
 
   // Templates.
   verifyFormat("template <class X> void f() {}\nint n;");
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index 568574bf73a872..a78d9a4df16025 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -509,6 +509,12 @@ TEST_F(TokenAnnotatorTest, UnderstandsVariables) {
   EXPECT_TOKEN(Tokens[1], tok::identifier, TT_Unknown);
   EXPECT_TOKEN(Tokens[2], tok::identifier, TT_StartOfName);
   EXPECT_TOKEN(Tokens[3], tok::l_brace, TT_Unknown);
+
+  Tokens = annotate("struct Foo<int> f{};");
+  EXPECT_EQ(Tokens.size(), 10u) << Tokens;
+  EXPECT_TOKEN(Tokens[1], tok::identifier, TT_Unknown);
+  EXPECT_TOKEN(Tokens[5], tok::identifier, TT_StartOfName);
+  EXPECT_TOKEN(Tokens[6], tok::l_brace, TT_Unknown);
 }
 
 TEST_F(TokenAnnotatorTest, UnderstandsVariableTemplates) {