[clang-format] QualifierOrder does not reorder template arguments

https://github.com/llvm/llvm-project/issues/53981

Reorder the qualifiers inside the template argument. This should handle the simple cases of

```
<const T>
<T const>
```

But only by relaxing that single letter capital variables are not possible macros

Fixes: #53981

Reviewed By: HazardyKnusperkeks, curdeius

Differential Revision: https://reviews.llvm.org/D120710

1 files changed, 18 insertions, 2 deletions

diff --git a/clang/lib/Format/QualifierAlignmentFixer.cpp b/clang/lib/Format/QualifierAlignmentFixer.cpp
index aff5562..7480202 100644
--- a/clang/lib/Format/QualifierAlignmentFixer.cpp
+++ b/clang/lib/Format/QualifierAlignmentFixer.cpp
@@ -224,6 +224,12 @@ const FormatToken *LeftRightQualifierAlignmentFixer::analyzeRight(
     rotateTokens(SourceMgr, Fixes, Tok, LastQual, /*Left=*/false);
     Tok = LastQual;
   } else if (Tok->startsSequence(QualifierType, tok::identifier,
+                                 TT_TemplateCloser)) {
+    FormatToken *Closer = Tok->Next->Next;
+    rotateTokens(SourceMgr, Fixes, Tok, Tok->Next, /*Left=*/false);
+    Tok = Closer;
+    return Tok;
+  } else if (Tok->startsSequence(QualifierType, tok::identifier,
                                  TT_TemplateOpener)) {
     // Read from the TemplateOpener to
     // TemplateCloser as in const ArrayRef<int> a; const ArrayRef<int> &a;
@@ -307,6 +313,11 @@ const FormatToken *LeftRightQualifierAlignmentFixer::analyzeLeft(
         rotateTokens(SourceMgr, Fixes, Tok, Tok->Next, /*Left=*/true);
         Tok = Tok->Next;
       }
+    } else if (Tok->startsSequence(tok::identifier, QualifierType,
+                                   TT_TemplateCloser)) {
+      FormatToken *Closer = Tok->Next->Next;
+      rotateTokens(SourceMgr, Fixes, Tok, Tok->Next, /*Left=*/true);
+      Tok = Closer;
     }
   }
   if (Tok->is(TT_TemplateOpener) && Tok->Next &&
@@ -329,8 +340,12 @@ const FormatToken *LeftRightQualifierAlignmentFixer::analyzeLeft(
         Next = Next->getNextNonComment();
       assert(Next->MatchingParen && "Missing template closer");
       Next = Next->MatchingParen;
+
+      // If the template closer is closing the requires clause,
+      // then stop and go back to the TemplateOpener and do whatever is
+      // inside the <>.
       if (Next->ClosesRequiresClause)
-        return Next;
+        return Next->MatchingParen;
       Next = Next->Next;
 
       // Move to the end of any template class members e.g.
@@ -461,7 +476,8 @@ bool LeftRightQualifierAlignmentFixer::isPossibleMacro(const FormatToken *Tok) {
   if (!Tok->is(tok::identifier))
     return false;
   if (Tok->TokenText.upper() == Tok->TokenText.str())
-    return true;
+    // T,K,U,V likely could be template arguments
+    return (Tok->TokenText.size() != 1);
   return false;
 }