[clang] fix partial ordering of NTTP packs

clang/docs/ReleaseNotes.rst

@@ -385,6 +385,7 @@ Bug Fixes to C++ Support
 - Improved fix for an issue with pack expansions of type constraints, where this
   now also works if the constraint has non-type or template template parameters.
   (#GH131798)
+- Fixes to partial ordering of non-type template parameter packs. (#GH132562)
 - Fix crash when evaluating the trailing requires clause of generic lambdas which are part of
   a pack expansion.
 - Fixes matching of nested template template parameters. (#GH130362)

clang/include/clang/AST/ExprCXX.h

@@ -4209,10 +4209,10 @@ class PackExpansionExpr : public Expr {
   Stmt *Pattern;
 
 public:
-  PackExpansionExpr(QualType T, Expr *Pattern, SourceLocation EllipsisLoc,
+  PackExpansionExpr(Expr *Pattern, SourceLocation EllipsisLoc,
                     UnsignedOrNone NumExpansions)
-      : Expr(PackExpansionExprClass, T, Pattern->getValueKind(),
-             Pattern->getObjectKind()),
+      : Expr(PackExpansionExprClass, Pattern->getType(),
+             Pattern->getValueKind(), Pattern->getObjectKind()),
         EllipsisLoc(EllipsisLoc),
         NumExpansions(NumExpansions ? *NumExpansions + 1 : 0),
         Pattern(Pattern) {

clang/include/clang/Sema/Sema.h

@@ -10126,13 +10126,14 @@ class Sema final : public SemaBase {
 
   /// Contexts in which a converted constant expression is required.
   enum CCEKind {
-    CCEK_CaseValue,    ///< Expression in a case label.
-    CCEK_Enumerator,   ///< Enumerator value with fixed underlying type.
-    CCEK_TemplateArg,  ///< Value of a non-type template parameter.
-    CCEK_InjectedTTP,  ///< Injected parameter of a template template parameter.
-    CCEK_ArrayBound,   ///< Array bound in array declarator or new-expression.
-    CCEK_ExplicitBool, ///< Condition in an explicit(bool) specifier.
-    CCEK_Noexcept,     ///< Condition in a noexcept(bool) specifier.
+    CCEK_CaseValue,     ///< Expression in a case label.
+    CCEK_Enumerator,    ///< Enumerator value with fixed underlying type.
+    CCEK_TemplateArg,   ///< Value of a non-type template parameter.
+    CCEK_TempArgStrict, ///< As above, but applies strict template checking
+                        ///< rules.
+    CCEK_ArrayBound,    ///< Array bound in array declarator or new-expression.
+    CCEK_ExplicitBool,  ///< Condition in an explicit(bool) specifier.
+    CCEK_Noexcept,      ///< Condition in a noexcept(bool) specifier.
     CCEK_StaticAssertMessageSize, ///< Call to size() in a static assert
                                   ///< message.
     CCEK_StaticAssertMessageData, ///< Call to data() in a static assert
@@ -11894,7 +11895,7 @@ class Sema final : public SemaBase {
                                    QualType InstantiatedParamType, Expr *Arg,
                                    TemplateArgument &SugaredConverted,
                                    TemplateArgument &CanonicalConverted,
-                                   bool MatchingTTP,
+                                   bool StrictCheck,
                                    CheckTemplateArgumentKind CTAK);
 
   /// Check a template argument against its corresponding

clang/lib/AST/ASTContext.cpp

@@ -5852,8 +5852,7 @@ TemplateArgument ASTContext::getInjectedTemplateArg(NamedDecl *Param) const {
                     T, VK, NTTP->getLocation());
 
     if (NTTP->isParameterPack())
-      E = new (*this)
-          PackExpansionExpr(DependentTy, E, NTTP->getLocation(), std::nullopt);
+      E = new (*this) PackExpansionExpr(E, NTTP->getLocation(), std::nullopt);
     Arg = TemplateArgument(E);
   } else {
     auto *TTP = cast<TemplateTemplateParmDecl>(Param);

clang/lib/AST/ASTImporter.cpp

@@ -8273,14 +8273,13 @@ ASTNodeImporter::VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E) {
 
 ExpectedStmt ASTNodeImporter::VisitPackExpansionExpr(PackExpansionExpr *E) {
   Error Err = Error::success();
-  auto ToType = importChecked(Err, E->getType());
-  auto ToPattern = importChecked(Err, E->getPattern());
+  auto *ToPattern = importChecked(Err, E->getPattern());
   auto ToEllipsisLoc = importChecked(Err, E->getEllipsisLoc());
   if (Err)
     return std::move(Err);
 
-  return new (Importer.getToContext()) PackExpansionExpr(
-      ToType, ToPattern, ToEllipsisLoc, E->getNumExpansions());
+  return new (Importer.getToContext())
+      PackExpansionExpr(ToPattern, ToEllipsisLoc, E->getNumExpansions());
 }
 
 ExpectedStmt ASTNodeImporter::VisitSizeOfPackExpr(SizeOfPackExpr *E) {

clang/lib/Sema/SemaOverload.cpp

@@ -6201,7 +6201,7 @@ static ExprResult BuildConvertedConstantExpression(Sema &S, Expr *From,
                                                    Sema::CCEKind CCE,
                                                    NamedDecl *Dest,
                                                    APValue &PreNarrowingValue) {
-  assert((S.getLangOpts().CPlusPlus11 || CCE == Sema::CCEK_InjectedTTP) &&
+  assert((S.getLangOpts().CPlusPlus11 || CCE == Sema::CCEK_TempArgStrict) &&
          "converted constant expression outside C++11 or TTP matching");
 
   if (checkPlaceholderForOverload(S, From))
@@ -6272,7 +6272,7 @@ static ExprResult BuildConvertedConstantExpression(Sema &S, Expr *From,
   // class type.
   ExprResult Result;
   bool IsTemplateArgument =
-      CCE == Sema::CCEK_TemplateArg || CCE == Sema::CCEK_InjectedTTP;
+      CCE == Sema::CCEK_TemplateArg || CCE == Sema::CCEK_TempArgStrict;
   if (T->isRecordType()) {
     assert(IsTemplateArgument &&
            "unexpected class type converted constant expr");
@@ -6325,7 +6325,7 @@ static ExprResult BuildConvertedConstantExpression(Sema &S, Expr *From,
     // value-dependent so we can't tell whether it's actually narrowing.
     // For matching the parameters of a TTP, the conversion is ill-formed
     // if it may narrow.
-    if (CCE != Sema::CCEK_InjectedTTP)
+    if (CCE != Sema::CCEK_TempArgStrict)
       break;
     [[fallthrough]];
   case NK_Type_Narrowing:
@@ -6400,7 +6400,7 @@ Sema::EvaluateConvertedConstantExpression(Expr *E, QualType T, APValue &Value,
   Expr::EvalResult Eval;
   Eval.Diag = &Notes;
 
-  assert(CCE != Sema::CCEK_InjectedTTP && "unnexpected CCE Kind");
+  assert(CCE != Sema::CCEK_TempArgStrict && "unnexpected CCE Kind");
 
   ConstantExprKind Kind;
   if (CCE == Sema::CCEK_TemplateArg && T->isRecordType())