[PATCH] D132031: Do not evaluate dependent immediate invocations

[Utkarsh Saxena via Phabricator via cfe-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rG0e0e8b65765e: Do not evaluate dependent immediate invocations (authored by usaxena95).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D132031/new/

https://reviews.llvm.org/D132031

Files:
  clang/docs/ReleaseNotes.rst
  clang/lib/Sema/SemaExpr.cpp
  clang/test/SemaCXX/cxx2a-consteval.cpp


Index: clang/test/SemaCXX/cxx2a-consteval.cpp
===================================================================
--- clang/test/SemaCXX/cxx2a-consteval.cpp
+++ clang/test/SemaCXX/cxx2a-consteval.cpp
@@ -648,9 +648,40 @@
 
 static_assert(bar<15>() == 15);
 static_assert(baz<int>() == sizeof(int));
-
 } // namespace value_dependent
 
+// https://github.com/llvm/llvm-project/issues/55601
+namespace issue_55601 {
+template<typename T>
+class Bar {
+  consteval static T x() { return 5; }  // expected-note {{non-constexpr constructor 'derp' cannot be used in a constant expression}}
+ public:
+  Bar() : a(x()) {} // expected-error {{call to consteval function 'issue_55601::Bar<issue_55601::derp>::x' is not a constant expression}}
+                    // expected-error at -1 {{call to consteval function 'issue_55601::derp::operator int' is not a constant expression}}
+                    // expected-note at -2 {{in call to 'x()'}}
+                    // expected-note at -3 {{non-literal type 'issue_55601::derp' cannot be used in a constant expression}}
+ private:
+  int a;
+};
+Bar<int> f;
+Bar<float> g;
+
+struct derp {
+  // Can't be used in a constant expression
+  derp(int); // expected-note {{declared here}}
+  consteval operator int() const { return 5; }
+};
+Bar<derp> a; // expected-note {{in instantiation of member function 'issue_55601::Bar<issue_55601::derp>::Bar' requested here}}
+
+struct constantDerp {
+  // Can be used in a constant expression.
+  consteval constantDerp(int) {} 
+  consteval operator int() const { return 5; }
+};
+Bar<constantDerp> b;
+
+} // namespace issue_55601
+
 namespace default_argument {
 
 // Previously calls of consteval functions in default arguments were rejected.
Index: clang/lib/Sema/SemaExpr.cpp
===================================================================
--- clang/lib/Sema/SemaExpr.cpp
+++ clang/lib/Sema/SemaExpr.cpp
@@ -19676,7 +19676,8 @@
 
   if (auto *FD = dyn_cast<FunctionDecl>(E->getDecl()))
     if (!isUnevaluatedContext() && !isConstantEvaluated() &&
-        FD->isConsteval() && !RebuildingImmediateInvocation)
+        FD->isConsteval() && !RebuildingImmediateInvocation &&
+        !FD->isDependentContext())
       ExprEvalContexts.back().ReferenceToConsteval.insert(E);
   MarkExprReferenced(*this, E->getLocation(), E->getDecl(), E, OdrUse,
                      RefsMinusAssignments);
Index: clang/docs/ReleaseNotes.rst
===================================================================
--- clang/docs/ReleaseNotes.rst
+++ clang/docs/ReleaseNotes.rst
@@ -159,6 +159,8 @@
   template instantiation to be constexpr/consteval even though a call to such
   a function cannot appear in a constant expression.
   (C++14 [dcl.constexpr]p6 (CWG DR647/CWG DR1358))
+- Correctly defer dependent immediate function invocations until template instantiation.
+  This fixes `GH55601 <https://github.com/llvm/llvm-project/issues/55601>`_.
 
 
 


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