From a7a74ece1d6b8dc95bf6fb0b7e06b8e0ba9b9559 Mon Sep 17 00:00:00 2001
From: cor3ntin <corentinjabot@gmail.com>
Date: Wed, 21 Feb 2024 20:53:44 +0100
Subject: [Clang] Fixes to immediate-escalating functions (#82281)

* Consider that immediate escalating function can appear at global
scope, fixing a crash

* Lambda conversion to function pointer was sometimes not performed in
an immediate function context when it should be.

Fixes #82258

(cherry picked from commit baf6bd303bd58a521809d456dd9b179636982fc5)
---
 clang/docs/ReleaseNotes.rst                      |  5 +++++
 clang/include/clang/Sema/Sema.h                  |  4 +++-
 clang/lib/Sema/SemaExpr.cpp                      |  4 ++--
 clang/test/SemaCXX/cxx2b-consteval-propagate.cpp | 26 ++++++++++++++++++++++++
 4 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 2411e97..fc27297 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -1099,6 +1099,11 @@ Bug Fixes to C++ Support
 - Fix incorrect code generation caused by the object argument of ``static operator()`` and ``static operator[]`` calls not being evaluated.
   Fixes (`#67976 <https://github.com/llvm/llvm-project/issues/67976>`_)
 
+- Fix crash when using an immediate-escalated function at global scope.
+  (`#82258 <https://github.com/llvm/llvm-project/issues/82258>`_)
+- Correctly immediate-escalate lambda conversion functions.
+  (`#82258 <https://github.com/llvm/llvm-project/issues/82258>`_)
+
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^
 - Fixed an import failure of recursive friend class template.
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 1f1cbd1..6adb8fb 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -1090,7 +1090,9 @@ public:
       if (FD) {
         FD->setWillHaveBody(true);
         S.ExprEvalContexts.back().InImmediateFunctionContext =
-            FD->isImmediateFunction();
+            FD->isImmediateFunction() ||
+            S.ExprEvalContexts[S.ExprEvalContexts.size() - 2]
+                .isConstantEvaluated();
         S.ExprEvalContexts.back().InImmediateEscalatingFunctionContext =
             S.getLangOpts().CPlusPlus20 && FD->isImmediateEscalating();
       } else
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 0d9c087..4cce0ab 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -18294,7 +18294,6 @@ void Sema::CheckUnusedVolatileAssignment(Expr *E) {
 }
 
 void Sema::MarkExpressionAsImmediateEscalating(Expr *E) {
-  assert(!FunctionScopes.empty() && "Expected a function scope");
   assert(getLangOpts().CPlusPlus20 &&
          ExprEvalContexts.back().InImmediateEscalatingFunctionContext &&
          "Cannot mark an immediate escalating expression outside of an "
@@ -18311,7 +18310,8 @@ void Sema::MarkExpressionAsImmediateEscalating(Expr *E) {
   } else {
     assert(false && "expected an immediately escalating expression");
   }
-  getCurFunction()->FoundImmediateEscalatingExpression = true;
+  if (FunctionScopeInfo *FI = getCurFunction())
+    FI->FoundImmediateEscalatingExpression = true;
 }
 
 ExprResult Sema::CheckForImmediateInvocation(ExprResult E, FunctionDecl *Decl) {
diff --git a/clang/test/SemaCXX/cxx2b-consteval-propagate.cpp b/clang/test/SemaCXX/cxx2b-consteval-propagate.cpp
index 531a626..4a75392 100644
--- a/clang/test/SemaCXX/cxx2b-consteval-propagate.cpp
+++ b/clang/test/SemaCXX/cxx2b-consteval-propagate.cpp
@@ -368,3 +368,29 @@ vector<void> v{};
 // expected-note@-2 {{in call to 'vector()'}}
 
 }
+
+
+namespace GH82258 {
+
+template <class R, class Pred>
+constexpr auto none_of(R&& r, Pred pred) -> bool { return true; }
+
+struct info { int value; };
+consteval auto is_invalid(info i) -> bool { return false; }
+constexpr info types[] = { {1}, {3}, {5}};
+
+static_assert(none_of(
+    types,
+    +[](info i) consteval {
+        return is_invalid(i);
+    }
+));
+
+static_assert(none_of(
+    types,
+    []{
+        return is_invalid;
+    }()
+));
+
+}
-- 
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