[clang] CTAD alias: fix transformation for require-clause expr Part2. (#93533)

In the https://github.com/llvm/llvm-project/pull/90961 fix, we miss a
case where the undeduced template parameters of the underlying deduction
guide are not transformed, which leaves incorrect depth/index
information, and causes crashes when evaluating constraints.

This patch fix this missing case.

Fixes #92596
Fixes #92212

2 files changed, 53 insertions, 1 deletions

diff --git a/clang/test/AST/ast-dump-ctad-alias.cpp b/clang/test/AST/ast-dump-ctad-alias.cpp
index a4b6f06..6f07a62 100644
--- a/clang/test/AST/ast-dump-ctad-alias.cpp
+++ b/clang/test/AST/ast-dump-ctad-alias.cpp
@@ -53,6 +53,33 @@ Out2<double>::AInner t(1.0);
 // CHECK-NEXT: |       | `-BuiltinType {{.*}} 'double'
 // CHECK-NEXT: |       `-ParmVarDecl {{.*}} 'double'
 
+// GH92596
+template <typename T0>
+struct Out3 {
+  template<class T1, typename T2>
+  struct Foo {
+    // Deduction guide:
+    //   template <typename T1, typename T2, typename V>
+    //   Foo(V, T1) -> Foo<T1, T2>;
+    template<class V> requires Concept<T0, V> // V in require clause of Foo deduction guide: depth 1, index: 2
+    Foo(V, T1);
+  };
+};
+template<class T3>
+using AFoo3 = Out3<int>::Foo<T3, T3>;
+AFoo3 afoo3{0, 1};
+// Verify occurrence V in the require-clause is transformed (depth: 1 => 0, index: 2 => 1) correctly.
+
+// CHECK:      FunctionTemplateDecl {{.*}} implicit <deduction guide for AFoo3>
+// CHECK-NEXT: |-TemplateTypeParmDecl {{.*}} class depth 0 index 0 T3
+// CHECK-NEXT: |-TemplateTypeParmDecl {{.*}} class depth 0 index 1 V
+// CHECK-NEXT: |-BinaryOperator {{.*}} '<dependent type>' '&&'
+// CHECK-NEXT: | |-UnresolvedLookupExpr {{.*}} '<dependent type>' lvalue (no ADL) = 'Concept'
+// CHECK-NEXT: | | |-TemplateArgument type 'int'
+// CHECK-NEXT: | | | `-BuiltinType {{.*}} 'int'
+// CHECK-NEXT: | | `-TemplateArgument type 'type-parameter-0-1'
+// CHECK-NEXT: | |   `-TemplateTypeParmType {{.*}} 'type-parameter-0-1' dependent depth 0 index 1
+
 template <typename... T1>
 struct Foo {
   Foo(T1...);
diff --git a/clang/test/SemaCXX/cxx20-ctad-type-alias.cpp b/clang/test/SemaCXX/cxx20-ctad-type-alias.cpp
index 3dafe82..a369ce6 100644
--- a/clang/test/SemaCXX/cxx20-ctad-type-alias.cpp
+++ b/clang/test/SemaCXX/cxx20-ctad-type-alias.cpp
@@ -266,7 +266,7 @@ template <typename U>
 using Bar = Foo<U>; // expected-note {{could not match 'Foo<type-parameter-0-0>' against 'int'}} \
                     // expected-note {{implicit deduction guide declared as 'template <typename U> requires __is_deducible(test18::Bar, Foo<type-parameter-0-0>) Bar(Foo<type-parameter-0-0>) -> Foo<type-parameter-0-0>'}} \
                     // expected-note {{candidate template ignored: constraints not satisfied}} \
-                    // expected-note {{implicit deduction guide declared as 'template <typename T> requires False<T> && __is_deducible(test18::Bar, Foo<int>) Bar(type-parameter-0-0) -> Foo<int>'}} \
+                    // expected-note {{implicit deduction guide declared as 'template <typename T> requires False<type-parameter-0-0> && __is_deducible(test18::Bar, Foo<int>) Bar(type-parameter-0-0) -> Foo<int>'}} \
                     // expected-note {{candidate function template not viable}} \
                     // expected-note {{implicit deduction guide declared as 'template <typename U> requires __is_deducible(test18::Bar, Foo<type-parameter-0-0>) Bar() -> Foo<type-parameter-0-0>'}}
 
@@ -414,4 +414,29 @@ struct A1 {
 template <typename U>
 using AFoo = A1<int>::A2<int>::Foo<U>;
 AFoo case3(1);
+
+// Case4: crashes on the constexpr evaluator due to the mixed-up index for the
+// template parameters `V`.
+template<class T, typename T2>
+struct Case4 {
+  template<class V> requires C<V>
+  Case4(V, T);
+};
+
+template<class T2>
+using ACase4 = Case4<T2, T2>;
+ACase4 case4{0, 1};
+
 } // namespace test24
+
+namespace GH92212 {
+template<typename T, typename...Us>
+struct A{
+  template<typename V> requires __is_same(V, int)
+  A(V);
+};
+
+template<typename...TS>
+using AA = A<int, TS...>;
+AA a{0};
+}