[clang-format] Fix template arguments in macros

Fixes https://github.com/llvm/llvm-project/issues/57738

old
```
#define FOO(typeName, realClass)                               \
  {                                                            \
#typeName, foo < FooType>(new foo <realClass>(#typeName))  \
  }
```
new
```
#define FOO(typeName, realClass)                                \
  { #typeName, foo<FooType>(new foo<realClass>(#typeName)) }
```

Previously, when an UnwrappedLine began with a hash in a macro
definition, the program incorrectly assumed the line was a preprocessor
directive.  It should be stringification.

The rule in spaceRequiredBefore was added in 8b5297117b.  Its purpose is
to add a space in an include directive.  It also added a space to a
template opener when the line began with a stringification hash.  So we
changed it.

Reviewed By: HazardyKnusperkeks, owenpan

Differential Revision: https://reviews.llvm.org/D133954

clang/lib/Format/TokenAnnotator.cpp

@@ -1427,7 +1427,7 @@ public:
     if (!CurrentToken)
       return LT_Invalid;
     NonTemplateLess.clear();
-    if (CurrentToken->is(tok::hash)) {
+    if (!Line.InMacroBody && CurrentToken->is(tok::hash)) {
       // We were not yet allowed to use C++17 optional when this was being
       // written. So we used LT_Invalid to mark that the line is not a
       // preprocessor directive.
@@ -4241,7 +4241,7 @@ bool TokenAnnotator::spaceRequiredBefore(const AnnotatedLine &Line,
     return false;
   }
   if (Right.is(tok::less) && Left.isNot(tok::l_paren) &&
-      Line.startsWith(tok::hash)) {
+      Line.Type == LT_ImportStatement) {
     return true;
   }
   if (Right.is(TT_TrailingUnaryOperator))

clang/lib/Format/TokenAnnotator.h

@@ -40,7 +40,7 @@ public:
       : First(Line.Tokens.front().Tok), Level(Line.Level),
         MatchingOpeningBlockLineIndex(Line.MatchingOpeningBlockLineIndex),
         MatchingClosingBlockLineIndex(Line.MatchingClosingBlockLineIndex),
-        InPPDirective(Line.InPPDirective),
+        InPPDirective(Line.InPPDirective), InMacroBody(Line.InMacroBody),
         MustBeDeclaration(Line.MustBeDeclaration), MightBeFunctionDecl(false),
         IsMultiVariableDeclStmt(false), Affected(false),
         LeadingEmptyLinesAffected(false), ChildrenAffected(false),
@@ -130,6 +130,7 @@ public:
   size_t MatchingOpeningBlockLineIndex;
   size_t MatchingClosingBlockLineIndex;
   bool InPPDirective;
+  bool InMacroBody;
   bool MustBeDeclaration;
   bool MightBeFunctionDecl;
   bool IsMultiVariableDeclStmt;

clang/lib/Format/UnwrappedLineParser.cpp

@@ -116,12 +116,14 @@ public:
     TokenSource = this;
     Line.Level = 0;
     Line.InPPDirective = true;
+    // InMacroBody gets set after the `#define x` part.
   }
 
   ~ScopedMacroState() override {
     TokenSource = PreviousTokenSource;
     ResetToken = Token;
     Line.InPPDirective = false;
+    Line.InMacroBody = false;
     Line.Level = PreviousLineLevel;
   }
 
@@ -196,6 +198,7 @@ public:
     Parser.Line = std::make_unique<UnwrappedLine>();
     Parser.Line->Level = PreBlockLine->Level;
     Parser.Line->InPPDirective = PreBlockLine->InPPDirective;
+    Parser.Line->InMacroBody = PreBlockLine->InMacroBody;
   }
 
   ~ScopedLineState() {
@@ -1253,6 +1256,7 @@ void UnwrappedLineParser::parsePPDefine() {
     Line->Level += PPBranchLevel + 1;
   addUnwrappedLine();
   ++Line->Level;
+  Line->InMacroBody = true;
 
   // Errors during a preprocessor directive can only affect the layout of the
   // preprocessor directive, and thus we ignore them. An alternative approach

clang/lib/Format/UnwrappedLineParser.h

@@ -46,6 +46,8 @@ struct UnwrappedLine {
 
   /// Whether this \c UnwrappedLine is part of a preprocessor directive.
   bool InPPDirective;
+  /// Whether it is part of a macro body.
+  bool InMacroBody;
 
   bool MustBeDeclaration;
 
@@ -353,8 +355,8 @@ struct UnwrappedLineNode {
 };
 
 inline UnwrappedLine::UnwrappedLine()
-    : Level(0), InPPDirective(false), MustBeDeclaration(false),
-      MatchingOpeningBlockLineIndex(kInvalidIndex) {}
+    : Level(0), InPPDirective(false), InMacroBody(false),
+      MustBeDeclaration(false), MatchingOpeningBlockLineIndex(kInvalidIndex) {}
 
 } // end namespace format
 } // end namespace clang

clang/unittests/Format/FormatTest.cpp

@@ -9864,6 +9864,10 @@ TEST_F(FormatTest, UnderstandsTemplateParameters) {
   verifyFormat("Constructor(A... a) : a_(X<A>{std::forward<A>(a)}...) {}");
   verifyFormat("< < < < < < < < < < < < < < < < < < < < < < < < < < < < < <");
   verifyFormat("some_templated_type<decltype([](int i) { return i; })>");
+
+  verifyFormat("#define FOO(typeName, realClass)                           \\\n"
+               "  { #typeName, foo<FooType>(new foo<realClass>(#typeName)) }",
+               getLLVMStyleWithColumns(60));
 }
 
 TEST_F(FormatTest, UnderstandsShiftOperators) {

clang/unittests/Format/TokenAnnotatorTest.cpp

@@ -284,6 +284,17 @@ TEST_F(TokenAnnotatorTest, UnderstandsVariableTemplates) {
   EXPECT_TOKEN(Tokens[13], tok::ampamp, TT_BinaryOperator);
 }
 
+TEST_F(TokenAnnotatorTest, UnderstandsTemplatesInMacros) {
+  auto Tokens =
+      annotate("#define FOO(typeName) \\\n"
+               "  { #typeName, foo<FooType>(new foo<realClass>(#typeName)) }");
+  ASSERT_EQ(Tokens.size(), 27u) << Tokens;
+  EXPECT_TOKEN(Tokens[11], tok::less, TT_TemplateOpener);
+  EXPECT_TOKEN(Tokens[13], tok::greater, TT_TemplateCloser);
+  EXPECT_TOKEN(Tokens[17], tok::less, TT_TemplateOpener);
+  EXPECT_TOKEN(Tokens[19], tok::greater, TT_TemplateCloser);
+}
+
 TEST_F(TokenAnnotatorTest, UnderstandsWhitespaceSensitiveMacros) {
   FormatStyle Style = getLLVMStyle();
   Style.WhitespaceSensitiveMacros.push_back("FOO");