[clang] [clang-format] Add LT_RequiresExpression and LT_SimpleRequirement (PR #121681)

[Owen Pan via cfe-commits]

https://github.com/owenca updated https://github.com/llvm/llvm-project/pull/121681

>From 14e26d9bb27724705e51fc134a4f3df2a09807e6 Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Sat, 4 Jan 2025 23:42:38 -0800
Subject: [PATCH 1/2] [clang-format] Add LT_RequiresExpression and
 LT_SimpleRequirement

The new line types help to annotate */&/&& in simple requirements as binary
operators.

Fixes #121675.
---
 clang/lib/Format/TokenAnnotator.cpp           | 24 +++++++++++++----
 clang/lib/Format/TokenAnnotator.h             |  2 ++
 clang/unittests/Format/TokenAnnotatorTest.cpp | 27 ++++++++++---------
 3 files changed, 36 insertions(+), 17 deletions(-)

diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index 945174ca9c5861..fa864f4c5e943d 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -1582,7 +1582,10 @@ class AnnotatingParser {
         return false;
       break;
     case tok::l_brace:
-      if (Style.Language == FormatStyle::LK_TextProto) {
+      if (IsCpp) {
+        if (Tok->is(TT_RequiresExpressionLBrace))
+          Line.Type = LT_RequiresExpression;
+      } else if (Style.Language == FormatStyle::LK_TextProto) {
         FormatToken *Previous = Tok->getPreviousNonComment();
         if (Previous && Previous->isNot(TT_DictLiteral))
           Previous->setType(TT_SelectorName);
@@ -2024,8 +2027,10 @@ class AnnotatingParser {
       if (!consumeToken())
         return LT_Invalid;
     }
-    if (Line.Type == LT_AccessModifier)
-      return LT_AccessModifier;
+    if (Line.Type == LT_AccessModifier || Line.Type == LT_RequiresExpression ||
+        Line.Type == LT_SimpleRequirement) {
+      return Line.Type;
+    }
     if (KeywordVirtualFound)
       return LT_VirtualFunctionDecl;
     if (ImportStatement)
@@ -3102,8 +3107,10 @@ class AnnotatingParser {
       }
     }
 
-    if (!Scopes.empty() && Scopes.back() == ST_CompoundRequirement)
+    if (Line.Type == LT_SimpleRequirement ||
+        (!Scopes.empty() && Scopes.back() == ST_CompoundRequirement)) {
       return TT_BinaryOperator;
+    }
 
     return TT_PointerOrReference;
   }
@@ -3693,8 +3700,15 @@ void TokenAnnotator::annotate(AnnotatedLine &Line) {
 
   if (!Line.Children.empty()) {
     ScopeStack.push_back(ST_ChildBlock);
-    for (auto &Child : Line.Children)
+    const bool InRequiresExpression = Line.Type == LT_RequiresExpression;
+    for (auto &Child : Line.Children) {
+      if (InRequiresExpression &&
+          !Child->First->isOneOf(tok::kw_typename, tok::kw_requires,
+                                 TT_CompoundRequirementLBrace)) {
+        Child->Type = LT_SimpleRequirement;
+      }
       annotate(*Child);
+    }
     // ScopeStack can become empty if Child has an unmatched `}`.
     if (!ScopeStack.empty())
       ScopeStack.pop_back();
diff --git a/clang/lib/Format/TokenAnnotator.h b/clang/lib/Format/TokenAnnotator.h
index 1a250e94d97c50..fa15517042f250 100644
--- a/clang/lib/Format/TokenAnnotator.h
+++ b/clang/lib/Format/TokenAnnotator.h
@@ -33,6 +33,8 @@ enum LineType {
   LT_VirtualFunctionDecl,
   LT_ArrayOfStructInitializer,
   LT_CommentAbovePPDirective,
+  LT_RequiresExpression,
+  LT_SimpleRequirement,
 };
 
 enum ScopeType {
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index a5b2d09a9f704d..0383780c2d84a2 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -370,6 +370,21 @@ TEST_F(TokenAnnotatorTest, UnderstandsUsesOfStarAndAmp) {
   ASSERT_EQ(Tokens.size(), 18u) << Tokens;
   EXPECT_TOKEN(Tokens[8], tok::r_paren, TT_CastRParen);
   EXPECT_TOKEN(Tokens[11], tok::star, TT_BinaryOperator);
+
+  Tokens = annotate("template <typename T>\n"
+                    "concept C = requires(T a, T b) { a && b; };");
+  ASSERT_EQ(Tokens.size(), 24u) << Tokens;
+  EXPECT_TOKEN(Tokens[16], tok::l_brace, TT_RequiresExpressionLBrace);
+  EXPECT_TOKEN(Tokens[18], tok::ampamp, TT_BinaryOperator);
+
+  Tokens = annotate("template <typename T, typename V>\n"
+                    "concept CheckMultiplicableBy = requires(T a, V b) {\n"
+                    "  { a * b } -> std::same_as<T>;\n"
+                    "};");
+  ASSERT_EQ(Tokens.size(), 36u) << Tokens;
+  EXPECT_TOKEN(Tokens[19], tok::l_brace, TT_RequiresExpressionLBrace);
+  EXPECT_TOKEN(Tokens[20], tok::l_brace, TT_CompoundRequirementLBrace);
+  EXPECT_TOKEN(Tokens[22], tok::star, TT_BinaryOperator);
 }
 
 TEST_F(TokenAnnotatorTest, UnderstandsUsesOfPlusAndMinus) {
@@ -1456,18 +1471,6 @@ TEST_F(TokenAnnotatorTest, UnderstandsRequiresExpressions) {
   EXPECT_TOKEN(Tokens[13], tok::l_brace, TT_RequiresExpressionLBrace);
 }
 
-TEST_F(TokenAnnotatorTest, CompoundRequirement) {
-  auto Tokens = annotate("template <typename T, typename V>\n"
-                         "concept CheckMultiplicableBy = requires(T a, V b) {\n"
-                         "  { a * b } -> std::same_as<T>;\n"
-                         "};");
-  ASSERT_EQ(Tokens.size(), 36u) << Tokens;
-
-  EXPECT_TOKEN(Tokens[19], tok::l_brace, TT_RequiresExpressionLBrace);
-  EXPECT_TOKEN(Tokens[20], tok::l_brace, TT_CompoundRequirementLBrace);
-  EXPECT_TOKEN(Tokens[22], tok::star, TT_BinaryOperator);
-}
-
 TEST_F(TokenAnnotatorTest, UnderstandsPragmaRegion) {
   // Everything after #pragma region should be ImplicitStringLiteral
   auto Tokens = annotate("#pragma region Foo(Bar: Hello)");

>From 5332319d9180238bb9d72f875b59c574effe691e Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Mon, 6 Jan 2025 01:15:37 -0800
Subject: [PATCH 2/2] NFC: use `Type` for `Line.Type`

---
 clang/lib/Format/TokenAnnotator.cpp | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index fa864f4c5e943d..e18e9a6fcd074b 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -2027,9 +2027,10 @@ class AnnotatingParser {
       if (!consumeToken())
         return LT_Invalid;
     }
-    if (Line.Type == LT_AccessModifier || Line.Type == LT_RequiresExpression ||
-        Line.Type == LT_SimpleRequirement) {
-      return Line.Type;
+    if (const auto Type = Line.Type; Type == LT_AccessModifier ||
+                                     Type == LT_RequiresExpression ||
+                                     Type == LT_SimpleRequirement) {
+      return Type;
     }
     if (KeywordVirtualFound)
       return LT_VirtualFunctionDecl;