Author: Younan Zhang Date: 2024-07-16T18:53:48+08:00 New Revision: 862715ea813d8ffa73050ada17567b45c41a1023
URL: https://github.com/llvm/llvm-project/commit/862715ea813d8ffa73050ada17567b45c41a1023 DIFF: https://github.com/llvm/llvm-project/commit/862715ea813d8ffa73050ada17567b45c41a1023.diff LOG: Revert "[Clang] Instantiate local constexpr functions eagerly (#95660)" (#98991) Unfortunately, #95660 has caused a regression in DeduceReturnType(), where some of the local recursive lambdas are getting incorrectly rejected. This reverts commit 5548ea34341e9d0ae645719c34b466ca3b9eaa5a. Also, this adds an offending case to the test. Closes #98526 Added: Modified: clang/docs/ReleaseNotes.rst clang/lib/Sema/SemaExpr.cpp clang/test/SemaTemplate/instantiate-local-class.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 969856a8f978c..615e8879ac474 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -1017,7 +1017,6 @@ Bug Fixes to C++ Support (#GH88081), (#GH89496), (#GH90669), (#GH91633) and (#GH97453). - Fixed a crash in constraint instantiation under nested lambdas with dependent parameters. - Fixed handling of brace ellison when building deduction guides. (#GH64625), (#GH83368). -- Clang now instantiates local constexpr functions eagerly for constant evaluators. (#GH35052), (#GH94849) - Fixed a failed assertion when attempting to convert an integer representing the diff erence between the addresses of two labels (a GNU extension) to a pointer within a constant expression. (#GH95366). - Fix immediate escalation bugs in the presence of dependent call arguments. (#GH94935) diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp index d6b85cbcaf56b..b0f953ea0a13a 100644 --- a/clang/lib/Sema/SemaExpr.cpp +++ b/clang/lib/Sema/SemaExpr.cpp @@ -17958,17 +17958,16 @@ void Sema::MarkFunctionReferenced(SourceLocation Loc, FunctionDecl *Func, if (FirstInstantiation || TSK != TSK_ImplicitInstantiation || Func->isConstexpr()) { - if (Func->isConstexpr()) + if (isa<CXXRecordDecl>(Func->getDeclContext()) && + cast<CXXRecordDecl>(Func->getDeclContext())->isLocalClass() && + CodeSynthesisContexts.size()) + PendingLocalImplicitInstantiations.push_back( + std::make_pair(Func, PointOfInstantiation)); + else if (Func->isConstexpr()) // Do not defer instantiations of constexpr functions, to avoid the // expression evaluator needing to call back into Sema if it sees a // call to such a function. InstantiateFunctionDefinition(PointOfInstantiation, Func); - else if (isa<CXXRecordDecl>(Func->getDeclContext()) && - cast<CXXRecordDecl>(Func->getDeclContext()) - ->isLocalClass() && - CodeSynthesisContexts.size()) - PendingLocalImplicitInstantiations.push_back( - std::make_pair(Func, PointOfInstantiation)); else { Func->setInstantiationIsPending(true); PendingInstantiations.push_back( diff --git a/clang/test/SemaTemplate/instantiate-local-class.cpp b/clang/test/SemaTemplate/instantiate-local-class.cpp index 7eee131e28d60..298233739900f 100644 --- a/clang/test/SemaTemplate/instantiate-local-class.cpp +++ b/clang/test/SemaTemplate/instantiate-local-class.cpp @@ -512,24 +512,26 @@ namespace LambdaInDefaultMemberInitializer { } #if __cplusplus >= 201703L -namespace GH35052 { -template <typename F> constexpr int func(F f) { - if constexpr (f(1UL)) { - return 1; +// Reduced from https://github.com/llvm/llvm-project/issues/98526 +// This relies on the deferral instantiation of the local lambda, otherwise we would fail in DeduceReturnType(). +namespace local_recursive_lambda { + +template <typename F> struct recursive_lambda { + template <typename... Args> auto operator()(Args &&...args) const { + return fn(*this, args...); } - return 0; -} + F fn; +}; -int main() { - auto predicate = [](auto v) /*implicit constexpr*/ -> bool { - return v == 1; - }; +template <typename F> recursive_lambda(F) -> recursive_lambda<F>; - static_assert(predicate(1)); - return func(predicate); +void foo() { + recursive_lambda{[&](auto &self_fn, int) -> int { + return self_fn(0); + }}(0); } -} // namespace GH35052 +} // namespace local_recursive_lambda #endif _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
