git merge main

Author: mingmingl-llvm

clang/docs/LanguageExtensions.rst

@@ -514,9 +514,7 @@ available in all language modes.
 __nullptr
 ---------
 
-``__nullptr`` is an alternate spelling for ``nullptr``, but is also available in
-C++ modes prior to C++11. Note that it's currently not availbale in C despite
-C23 having support for ``nullptr``.
+``__nullptr`` is an alternate spelling for ``nullptr``. It is available in all C and C++ language modes.
 
 __signed, __signed__
 --------------------

clang/docs/ReleaseNotes.rst

@@ -388,6 +388,7 @@ C Language Changes
 
 - Extend clang's ``<limits.h>`` to define ``LONG_LONG_*`` macros for Android's bionic.
 - Macro ``__STDC_NO_THREADS__`` is no longer necessary for MSVC 2022 1939 and later.
+- Exposed the the ``__nullptr`` keyword as an alias for ``nullptr`` in all C language modes.
 
 C2y Feature Support
 ^^^^^^^^^^^^^^^^^^^
@@ -1003,7 +1004,6 @@ Bug Fixes to C++ Support
 - Fixed assertions or false compiler diagnostics in the case of C++ modules for
   lambda functions or inline friend functions defined inside templates (#GH122493).
 - Clang now rejects declaring an alias template with the same name as its template parameter. (#GH123423)
-- Fix that some dependent immediate expressions did not cause immediate escalation (#GH119046)
 - Fixed the rejection of valid code when referencing an enumerator of an unscoped enum member with a prior declaration. (#GH124405)
 - Fixed immediate escalation of non-dependent expressions. (#GH123405)
 - Fix type of expression when calling a template which returns an ``__array_rank`` querying a type depending on a

clang/include/clang/Basic/TokenKinds.def

@@ -707,7 +707,7 @@ ALIAS("__decltype"       , decltype     , KEYCXX)
 ALIAS("__imag__"         , __imag       , KEYALL)
 ALIAS("__inline"         , inline       , KEYALL)
 ALIAS("__inline__"       , inline       , KEYALL)
-ALIAS("__nullptr"        , nullptr      , KEYCXX)
+ALIAS("__nullptr"        , nullptr      , KEYALL)
 ALIAS("__real__"         , __real       , KEYALL)
 ALIAS("__restrict"       , restrict     , KEYALL)
 ALIAS("__restrict__"     , restrict     , KEYALL)

clang/include/clang/Sema/Sema.h

@@ -13139,10 +13139,10 @@ class Sema final : public SemaBase {
     ~SynthesizedFunctionScope() {
       if (PushedCodeSynthesisContext)
         S.popCodeSynthesisContext();
-
-      if (auto *FD = dyn_cast<FunctionDecl>(S.CurContext))
+      if (auto *FD = dyn_cast<FunctionDecl>(S.CurContext)) {
         FD->setWillHaveBody(false);
-
+        S.CheckImmediateEscalatingFunctionDefinition(FD, S.getCurFunction());
+      }
       S.PopExpressionEvaluationContext();
       S.PopFunctionScopeInfo();
     }

clang/lib/Sema/SemaDecl.cpp

@@ -16019,6 +16019,7 @@ Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body,
       if (!FD->isDeletedAsWritten())
         FD->setBody(Body);
       FD->setWillHaveBody(false);
+      CheckImmediateEscalatingFunctionDefinition(FD, FSI);
 
       if (getLangOpts().CPlusPlus14) {
         if (!FD->isInvalidDecl() && Body && !FD->isDependentContext() &&

clang/lib/Sema/SemaExpr.cpp

@@ -17881,9 +17881,6 @@ void Sema::PopExpressionEvaluationContext() {
   WarnOnPendingNoDerefs(Rec);
   HandleImmediateInvocations(*this, Rec);
 
-  if (auto *FD = dyn_cast<FunctionDecl>(CurContext); FD && getCurFunction())
-    CheckImmediateEscalatingFunctionDefinition(FD, getCurFunction());
-
   // Warn on any volatile-qualified simple-assignments that are not discarded-
   // value expressions nor unevaluated operands (those cases get removed from
   // this list by CheckUnusedVolatileAssignment).

clang/test/CodeGenCXX/gh119046.cpp

@@ -6,3 +6,7 @@ int nullptr; // expected-warning {{'nullptr' is a keyword in C23}}
 
 nullptr_t val; // expected-error {{unknown type name 'nullptr_t'}}
 
+void foo(void *);
+void bar() { foo(__nullptr); } // Test that it converts properly to an arbitrary pointer type without warning
+_Static_assert(__nullptr == 0, "value of __nullptr"); // Test that its value matches that of NULL
+_Static_assert(_Generic(__typeof(__nullptr), int : 0, void * : 0, default : 1), "type of __nullptr"); // Test that it's type is not the same as what NULL would generally have.

clang/test/Sema/nullptr-prec2x.c

@@ -108,3 +108,10 @@ void test_f1() {
   int ir = (f1)(nullptr);
 }
 
+// __nullptr keyword in C
+void foo(void *);
+void bar() { foo(__nullptr); }
+static_assert(nullptr == __nullptr);
+static_assert(__nullptr == 0);  // Test that its value matches that of NULL
+static_assert(_Generic(typeof(__nullptr), nullptr_t: true, default: false));
+static_assert(_Generic(__typeof(__nullptr), int : 0, void * : 0, default : 1)); // Test that it's type is not the same as what NULL would generally have.

clang/test/Sema/nullptr.c

@@ -529,23 +529,6 @@ D d(0); // expected-note {{in implicit initialization for inherited constructor
 
 }
 
-namespace GH119046 {
-
-template <typename Cls> constexpr auto tfn(int) {
-  return (unsigned long long)(&Cls::sfn);
-  //expected-note@-1 {{'tfn<GH119046::S>' is an immediate function because its body evaluates the address of a consteval function 'sfn'}}
-};
-struct S { static consteval void sfn() {} };
-
-int f() {
-  int a = 0; // expected-note{{declared here}}
-  return tfn<S>(a);
-  //expected-error@-1 {{call to immediate function 'GH119046::tfn<GH119046::S>' is not a constant expression}}
-  //expected-note@-2 {{read of non-const variable 'a' is not allowed in a constant expression}}
-}
-
-}
-
 namespace GH123405 {
 
 consteval void fn() {}