[clang-format] Correctly format variable templates.

Fixes https://github.com/llvm/llvm-project/issues/54257.

Reviewed By: MyDeveloperDay, HazardyKnusperkeks, owenpan

Differential Revision: https://reviews.llvm.org/D121456

diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index 0c760b5..f0a17af 100644 (file)
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -1526,8 +1526,36 @@ private:
       if (Current.getPrecedence() != prec::Assignment)
         return false;
 
-      if (Line.First->isOneOf(tok::kw_template, tok::kw_using, tok::kw_return))
+      if (Line.First->isOneOf(tok::kw_using, tok::kw_return))
         return false;
+      if (Line.First->is(tok::kw_template)) {
+        assert(Current.Previous);
+        if (Current.Previous->is(tok::kw_operator)) {
+          // `template ... operator=` cannot be an expression.
+          return false;
+        }
+
+        // `template` keyword can start a variable template.
+        const FormatToken *Tok = Line.First->getNextNonComment();
+        assert(Tok); // Current token is on the same line.
+        if (Tok->isNot(TT_TemplateOpener)) {
+          // Explicit template instantiations do not have `<>`.
+          return false;
+        }
+
+        Tok = Tok->MatchingParen;
+        if (!Tok)
+          return false;
+        Tok = Tok->getNextNonComment();
+        if (!Tok)
+          return false;
+
+        if (Tok->isOneOf(tok::kw_class, tok::kw_enum, tok::kw_concept,
+                         tok::kw_struct, tok::kw_using))
+          return false;
+
+        return true;
+      }
 
       // Type aliases use `type X = ...;` in TypeScript and can be exported
       // using `export type ...`.

diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 557438d..459cbf1 100644 (file)
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -25657,6 +25657,12 @@ TEST_F(FormatTest, AlignArrayOfStructuresRightAlignmentNonSquare) {
                Style);
 }
 
+TEST_F(FormatTest, FormatsVariableTemplates) {
+  verifyFormat("inline bool var = is_integral_v<int> && is_signed_v<int>;");
+  verifyFormat("template <typename T> "
+               "inline bool var = is_integral_v<T> && is_signed_v<T>;");
+}
+
 } // namespace
 } // namespace format
 } // namespace clang

diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index 9240e81..cc624d0 100644 (file)
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -131,6 +131,31 @@ TEST_F(TokenAnnotatorTest, UnderstandsEnums) {
   EXPECT_TOKEN(Tokens[2], tok::l_brace, TT_EnumLBrace);
 }
 
+TEST_F(TokenAnnotatorTest, UnderstandsDefaultedAndDeletedFunctions) {
+  auto Tokens = annotate("auto operator<=>(const T &) const & = default;");
+  EXPECT_EQ(Tokens.size(), 14u) << Tokens;
+  EXPECT_TOKEN(Tokens[9], tok::amp, TT_PointerOrReference);
+
+  Tokens = annotate("template <typename T> void F(T) && = delete;");
+  EXPECT_EQ(Tokens.size(), 15u) << Tokens;
+  EXPECT_TOKEN(Tokens[10], tok::ampamp, TT_PointerOrReference);
+}
+
+TEST_F(TokenAnnotatorTest, UnderstandsVariables) {
+  auto Tokens =
+      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);
+}
+
+TEST_F(TokenAnnotatorTest, UnderstandsVariableTemplates) {
+  auto Tokens =
+      annotate("template <typename T> "
+               "inline bool var = is_integral_v<int> && is_signed_v<int>;");
+  EXPECT_EQ(Tokens.size(), 20u) << Tokens;
+  EXPECT_TOKEN(Tokens[13], tok::ampamp, TT_BinaryOperator);
+}
+
 TEST_F(TokenAnnotatorTest, UnderstandsLBracesInMacroDefinition) {
   auto Tokens = annotate("#define BEGIN NS {");
   EXPECT_EQ(Tokens.size(), 6u) << Tokens;
@@ -164,17 +189,17 @@ TEST_F(TokenAnnotatorTest, UnderstandsFunctionRefQualifiers) {
   EXPECT_EQ(Tokens.size(), 7u) << Tokens;
   EXPECT_TOKEN(Tokens[4], tok::amp, TT_PointerOrReference);
 
-  Tokens = annotate("void operator=() &&;");
-  EXPECT_EQ(Tokens.size(), 8u) << Tokens;
-  EXPECT_TOKEN(Tokens[5], tok::ampamp, TT_PointerOrReference);
+  Tokens = annotate("void operator=(T) &&;");
+  EXPECT_EQ(Tokens.size(), 9u) << Tokens;
+  EXPECT_TOKEN(Tokens[6], tok::ampamp, TT_PointerOrReference);
 
   Tokens = annotate("template <typename T> void f() &;");
   EXPECT_EQ(Tokens.size(), 12u) << Tokens;
   EXPECT_TOKEN(Tokens[9], tok::amp, TT_PointerOrReference);
 
-  Tokens = annotate("template <typename T> void operator=() &;");
-  EXPECT_EQ(Tokens.size(), 13u) << Tokens;
-  EXPECT_TOKEN(Tokens[10], tok::amp, TT_PointerOrReference);
+  Tokens = annotate("template <typename T> void operator=(T) &;");
+  EXPECT_EQ(Tokens.size(), 14u) << Tokens;
+  EXPECT_TOKEN(Tokens[11], tok::amp, TT_PointerOrReference);
 }
 
 TEST_F(TokenAnnotatorTest, UnderstandsRequiresClausesAndConcepts) {