[Clang] Static member initializers are not immediate escalating context.

clang/docs/ReleaseNotes.rst

@@ -287,6 +287,9 @@ Bug Fixes to C++ Support
   a non-template inner-class between the function and the class template.
   (`#65810 <https://github.com/llvm/llvm-project/issues/65810>`_)
 
+- Fix a crash when calling a non-constant immediate function
+  in the initializer of a static data member.
+  (`#65985 <https://github.com/llvm/llvm-project/issues/65985>_`).
 - Clang now properly converts static lambda call operator to function
   pointers on win32.
   (`#62594 <https://github.com/llvm/llvm-project/issues/62594>`_)

clang/lib/Parse/ParseDeclCXX.cpp

@@ -3232,13 +3232,21 @@ ExprResult Parser::ParseCXXMemberInitializer(Decl *D, bool IsFunction,
   assert(Tok.isOneOf(tok::equal, tok::l_brace) &&
          "Data member initializer not starting with '=' or '{'");
 
+  bool IsFieldInitialization = isa_and_present<FieldDecl>(D);
+
   EnterExpressionEvaluationContext Context(
       Actions,
-      isa_and_present<FieldDecl>(D)
+      IsFieldInitialization
           ? Sema::ExpressionEvaluationContext::PotentiallyEvaluatedIfUsed
           : Sema::ExpressionEvaluationContext::PotentiallyEvaluated,
       D);
-  Actions.ExprEvalContexts.back().InImmediateEscalatingFunctionContext = true;
+
+  // CWG2760
+  // Default member initializers used to initialize a base or member subobject
+  // [...] are considered to be part of the function body
+  Actions.ExprEvalContexts.back().InImmediateEscalatingFunctionContext =
+      IsFieldInitialization;
+
   if (TryConsumeToken(tok::equal, EqualLoc)) {
     if (Tok.is(tok::kw_delete)) {
       // In principle, an initializer of '= delete p;' is legal, but it will

clang/test/SemaCXX/cxx2a-consteval.cpp

@@ -1126,4 +1126,53 @@ int  test2() { return h{nullptr}; }
 // expected-note@-2 {{subobject 'g' is not initialized}}
 
 
+}
+
+namespace GH65985 {
+
+int consteval operator""_foo(unsigned long long V) {
+    return 0;
+}
+int consteval operator""_bar(unsigned long long V); // expected-note 3{{here}}
+
+int consteval f() {
+  return 0;
+}
+
+int consteval g();  // expected-note {{here}}
+
+
+struct C {
+    static const int a = 1_foo;
+    static constexpr int b = 1_foo;
+    static const int c = 1_bar; // expected-error {{call to consteval function 'GH65985::operator""_bar' is not a constant expression}} \
+                                // expected-note {{undefined function 'operator""_bar' cannot be used in a constant expression}} \
+                                // expected-error {{in-class initializer for static data member is not a constant expression}}
+
+    // FIXME: remove duplicate diagnostics
+    static constexpr int d = 1_bar; // expected-error {{call to consteval function 'GH65985::operator""_bar' is not a constant expression}} \
+                                    // expected-note {{undefined function 'operator""_bar' cannot be used in a constant expression}} \
+                                    // expected-error {{constexpr variable 'd' must be initialized by a constant expression}}  \
+                                    // expected-note {{undefined function 'operator""_bar' cannot be used in a constant expression}}
+
+    static const int e = f();
+    static const int f = g(); // expected-error {{call to consteval function 'GH65985::g' is not a constant expression}} \
+                              // expected-error {{in-class initializer for static data member is not a constant expression}} \
+                              // expected-note  {{undefined function 'g' cannot be used in a constant expression}}
+};
+
+}
+
+namespace GH66562 {
+
+namespace ns
+{
+    consteval int foo(int x) { return 1; } // expected-note {{declared here}}
+}
+
+template <class A>
+struct T {
+    static constexpr auto xx = ns::foo(A{}); // expected-error {{cannot take address of consteval function 'foo' outside of an immediate invocation}}
+};
+
 }

clang/test/SemaCXX/cxx2b-consteval-propagate.cpp

@@ -331,6 +331,21 @@ S s(0); // expected-note {{in the default initializer of 'j'}}
 
 }
 
+namespace GH65985 {
+consteval int invalid(); // expected-note 2{{declared here}}
+constexpr int escalating(auto) {
+    return invalid();
+    // expected-note@-1 {{'escalating<int>' is an immediate function because its body contains a call to a consteval function 'invalid' and that call is not a constant expression}}
+    // expected-note@-2 2{{undefined function 'invalid' cannot be used in a constant expression}}
+}
+struct S {
+    static constexpr int a = escalating(0); // expected-note 2{{in call to}}
+    // expected-error@-1 {{call to immediate function 'GH65985::escalating<int>' is not a constant expression}}
+    // expected-error@-2 {{constexpr variable 'a' must be initialized by a constant expression}}
+};
+
+}
+
 namespace GH66324 {
 
 consteval int allocate();  // expected-note  2{{declared here}}