From 98aff7d4fcf8aa2f63643915dad08df4c4c557a6 Mon Sep 17 00:00:00 2001
From: Younan Zhang <zyn7109@gmail.com>
Date: Mon, 7 Oct 2024 09:38:19 +0800
Subject: [PATCH] [Clang] Remove the special-casing for RequiresExprBodyDecl in
 BuildResolvedCallExpr() after fd87d765c0 (#111277)

The special-casing for RequiresExprBodyDecl caused a regression, as
reported in #110785.

The original fix for #84020 has been superseded by fd87d765c0, which
establishes a `DependentScopeDeclRefExpr` instead of a
`CXXDependentScopeMemberExpr` for the case in issue. So the spurious
diagnostic in #84020 would no longer occur.

This also merges the test for #84020 together with that for #110785 into
clang/test/SemaTemplate/instantiate-requires-expr.cpp.

No release note because I think this merits a backport.

Fixes #110785

(cherry picked from commit 8c1547055eaf65003f3e6fd024195f4926ff2356)
---
 clang/lib/Sema/SemaExpr.cpp                   |  3 +-
 clang/lib/Sema/TreeTransform.h                |  2 +-
 clang/test/SemaCXX/PR84020.cpp                | 23 --------------
 .../instantiate-requires-expr.cpp             | 31 +++++++++++++++++++
 4 files changed, 33 insertions(+), 26 deletions(-)
 delete mode 100644 clang/test/SemaCXX/PR84020.cpp

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index f56ca398cda81c..687b1be9459219 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -6922,8 +6922,7 @@ ExprResult Sema::BuildResolvedCallExpr(Expr *Fn, NamedDecl *NDecl,
   }
 
   if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(FDecl))
-    if (!isa<RequiresExprBodyDecl>(CurContext) &&
-        Method->isImplicitObjectMemberFunction())
+    if (Method->isImplicitObjectMemberFunction())
       return ExprError(Diag(LParenLoc, diag::err_member_call_without_object)
                        << Fn->getSourceRange() << 0);
 
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 51e6a4845bf6fd..0ae393524fe03a 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -13608,7 +13608,7 @@ bool TreeTransform<Derived>::TransformOverloadExprDecls(OverloadExpr *Old,
     }
 
     AllEmptyPacks &= Decls.empty();
-  };
+  }
 
   // C++ [temp.res]/8.4.2:
   //   The program is ill-formed, no diagnostic required, if [...] lookup for
diff --git a/clang/test/SemaCXX/PR84020.cpp b/clang/test/SemaCXX/PR84020.cpp
deleted file mode 100644
index 8ea5dcc4527ae7..00000000000000
--- a/clang/test/SemaCXX/PR84020.cpp
+++ /dev/null
@@ -1,23 +0,0 @@
-// RUN: %clang_cc1 -std=c++20 -verify %s
-// RUN: %clang_cc1 -std=c++23 -verify %s
-// expected-no-diagnostics
-
-struct B {
-    template <typename S>
-    void foo();
-
-    void bar();
-};
-
-template <typename T, typename S>
-struct A : T {
-    auto foo() {
-        static_assert(requires { T::template foo<S>(); });
-        static_assert(requires { T::bar(); });
-    }
-};
-
-int main() {
-    A<B, double> a;
-    a.foo();
-}
diff --git a/clang/test/SemaTemplate/instantiate-requires-expr.cpp b/clang/test/SemaTemplate/instantiate-requires-expr.cpp
index 20a19d731ae169..a1f5456156a06f 100644
--- a/clang/test/SemaTemplate/instantiate-requires-expr.cpp
+++ b/clang/test/SemaTemplate/instantiate-requires-expr.cpp
@@ -237,3 +237,34 @@ constexpr bool e_v = true;
 static_assert(e_v<bool>);
 
 } // namespace GH73885
+
+namespace GH84020 {
+
+struct B {
+  template <typename S> void foo();
+  void bar();
+};
+
+template <typename T, typename S> struct A : T {
+  void foo() {
+    static_assert(requires { T::template foo<S>(); });
+    static_assert(requires { T::bar(); });
+  }
+};
+
+template class A<B, double>;
+
+} // namespace GH84020
+
+namespace GH110785 {
+
+struct Foo {
+  static void f(auto) requires(false) {}
+  void f(int) {}
+
+  static_assert([](auto v) {
+    return requires { f(v); };
+  } (0) == false);
+};
+
+} // namespace GH110785