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

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

Fixes #121675.

Author: owenca

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 +2027,11 @@ class AnnotatingParser {
       if (!consumeToken())
         return LT_Invalid;
     }
-    if (Line.Type == LT_AccessModifier)
-      return LT_AccessModifier;
+    if (const auto Type = Line.Type; Type == LT_AccessModifier ||
+                                     Type == LT_RequiresExpression ||
+                                     Type == LT_SimpleRequirement) {
+      return Type;
+    }
     if (KeywordVirtualFound)
       return LT_VirtualFunctionDecl;
     if (ImportStatement)
@@ -3102,8 +3108,10 @@ 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 +3701,15 @@ 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();

clang/lib/Format/TokenAnnotator.h

@@ -33,6 +33,8 @@ enum LineType {
   LT_VirtualFunctionDecl,
   LT_ArrayOfStructInitializer,
   LT_CommentAbovePPDirective,
+  LT_RequiresExpression,
+  LT_SimpleRequirement,
 };
 
 enum ScopeType {

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)");