Author: Utkarsh Saxena Date: 2024-01-19T08:23:25+01:00 New Revision: 498e1c2257da552abc58aa75f6b9f776bf826f86
URL: https://github.com/llvm/llvm-project/commit/498e1c2257da552abc58aa75f6b9f776bf826f86 DIFF: https://github.com/llvm/llvm-project/commit/498e1c2257da552abc58aa75f6b9f776bf826f86.diff LOG: [coroutine] Create coroutine body in the correct eval context (#78589) Fixes: https://github.com/llvm/llvm-project/issues/78290 See the bug for more context. ```cpp Gen ACoroutine() { if constexpr (0) // remove it make clang compile. co_return; co_await Gen{}; } ``` We miss symbol of ctor of promise_type if the first coroutine statement happens to be inside the disabled branch of `if constexpr`. This happens because the promise object is built when we see the first coroutine statement which is present in `ExpressionEvaluationContext::DiscardedStatement` context due to `if constexpr (0)`. This makes clang believe that the promise constructor is only odr-used and not really "used". The expr evaluation context for the coroutine body should not be related to the context in which the first coroutine statement appears. We override the context to `PotentiallyEvaluated`. --------- Co-authored-by: cor3ntin <corentinja...@gmail.com> Added: clang/test/SemaCXX/coroutine-promise-ctor.cpp Modified: clang/docs/ReleaseNotes.rst clang/lib/Sema/SemaCoroutine.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index b400d75095421c7..63f756f30873c64 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -804,6 +804,9 @@ Bug Fixes in This Version Objective-C++ property accesses to not be converted to a function call to the getter in the placement-args of new-expressions. Fixes (`#65053 <https://github.com/llvm/llvm-project/issues/65053>`_) +- Fix an issue with missing symbol definitions when the first coroutine + statement appears in a discarded ``if constexpr`` branch. + Fixes (`#78290 <https://github.com/llvm/llvm-project/issues/78290>`_) Bug Fixes to Compiler Builtins ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/Sema/SemaCoroutine.cpp b/clang/lib/Sema/SemaCoroutine.cpp index 0e0f8f67dcd73e1..4e600fd29ee7395 100644 --- a/clang/lib/Sema/SemaCoroutine.cpp +++ b/clang/lib/Sema/SemaCoroutine.cpp @@ -21,6 +21,7 @@ #include "clang/AST/StmtCXX.h" #include "clang/Basic/Builtins.h" #include "clang/Lex/Preprocessor.h" +#include "clang/Sema/EnterExpressionEvaluationContext.h" #include "clang/Sema/Initialization.h" #include "clang/Sema/Overload.h" #include "clang/Sema/ScopeInfo.h" @@ -773,6 +774,9 @@ bool Sema::checkFinalSuspendNoThrow(const Stmt *FinalSuspend) { bool Sema::ActOnCoroutineBodyStart(Scope *SC, SourceLocation KWLoc, StringRef Keyword) { + // Ignore previous expr evaluation contexts. + EnterExpressionEvaluationContext PotentiallyEvaluated( + *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated); if (!checkCoroutineContext(*this, KWLoc, Keyword)) return false; auto *ScopeInfo = getCurFunction(); diff --git a/clang/test/SemaCXX/coroutine-promise-ctor.cpp b/clang/test/SemaCXX/coroutine-promise-ctor.cpp new file mode 100644 index 000000000000000..7a06299712cb774 --- /dev/null +++ b/clang/test/SemaCXX/coroutine-promise-ctor.cpp @@ -0,0 +1,34 @@ +// RUN: %clang_cc1 -std=c++20 -ast-dump %s | FileCheck %s +#include "Inputs/std-coroutine.h" + +// Github issue: https://github.com/llvm/llvm-project/issues/78290 +namespace GH78290 { +class Gen { + public: + class promise_type { + public: + template<typename... Args> + explicit promise_type(Args...) {} + // CHECK: CXXConstructorDecl {{.*}} used promise_type 'void ()' {{.*}} + // CHECK-NEXT: TemplateArgument pack + // CHECK-NEXT: CompoundStmt {{.*}} + Gen get_return_object() { return {}; } + + void unhandled_exception() {} + void return_void() {} + std::suspend_always await_transform(Gen gen) { return {}; } + + std::suspend_always initial_suspend() { return {}; } + // CHECK: CXXMethodDecl {{.*}} used initial_suspend {{.*}} + std::suspend_always final_suspend() noexcept { return {}; } + // CHECK: CXXMethodDecl {{.*}} used final_suspend {{.*}} + }; +}; + +Gen CoroutineBody() { + if constexpr (0) { + co_await Gen{}; + } + co_await Gen{}; +} +} // namespace GH78290 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
