https://github.com/babadany2999 updated https://github.com/llvm/llvm-project/pull/213449
>From db3e8ab18e94e552c4e48dc128373c66b9551491 Mon Sep 17 00:00:00 2001 From: Baba Dan Constantin <[email protected]> Date: Sat, 1 Aug 2026 17:09:50 +0300 Subject: [PATCH 1/3] [clang][constexpr] Allow IndirectGotoStmt in constexpr functions for C++23 P2242R3 ("More Relaxed Constexpr Functions") permitted jump statements such as `goto` and labels inside `constexpr` functions starting in C++23. When handling `GotoStmtClass` and `LabelStmtClass` in `CheckConstexprFunctionStmt`, `IndirectGotoStmtClass` (GNU computed goto) was inadvertently omitted. As a result, any indirect goto inside a `constexpr` function body hit the default case in `CheckConstexprFunctionStmt` and triggered an unrecoverable hard error (`err_constexpr_body_invalid_stmt`), even when placed in unexecuted branches (e.g. behind `if consteval`). This commit adds `case Stmt::IndirectGotoStmtClass:` alongside `GotoStmtClass` so that indirect gotos are treated consistently: - Permitted in C++23 `constexpr` functions. - Allowed in earlier standard dialects (C++11/14/17/20) as a C++23 extension warning. - Evaluated properly by constant evaluation (which rejects actual compile-time execution of computed gotos if reached). Regression test added to `clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p3.cpp`. --- clang/lib/Sema/SemaDeclCXX.cpp | 1 + clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p3.cpp | 8 ++++++++ 2 files changed, 9 insertions(+) diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp index 47b01b913b428..76b3d8cca9701 100644 --- a/clang/lib/Sema/SemaDeclCXX.cpp +++ b/clang/lib/Sema/SemaDeclCXX.cpp @@ -2343,6 +2343,7 @@ CheckConstexprFunctionStmt(Sema &SemaRef, const FunctionDecl *Dcl, Stmt *S, case Stmt::LabelStmtClass: case Stmt::GotoStmtClass: + case Stmt::IndirectGotoStmtClass: if (Cxx2bLoc.isInvalid()) Cxx2bLoc = S->getBeginLoc(); for (Stmt *SubStmt : S->children()) { diff --git a/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p3.cpp b/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p3.cpp index 51990ee4341d2..508941ae0429d 100644 --- a/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p3.cpp +++ b/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p3.cpp @@ -167,6 +167,14 @@ constexpr int DisallowedStmtsCXX14_7() { int n; // beforecxx20-warning {{uninitialized variable in a constexpr function}} } +constexpr int DisallowedStmtsCXX14_8() { + return 0; // beforecxx14-note {{previous}} + // - an indirect goto statement + goto *(&&x); // beforecxx23-warning {{use of this statement in a constexpr function is a C++23 extension}} + x:; + return 0; // beforecxx14-warning {{multiple return}} +} + constexpr int ForStmt() { for (int n = 0; n < 10; ++n) {} // beforecxx14-error {{statement not allowed in constexpr function}} return 0; >From 08b3e6677f1b522f31a6222bdd16833533053cc6 Mon Sep 17 00:00:00 2001 From: Baba Dan Constantin <[email protected]> Date: Sat, 1 Aug 2026 20:53:59 +0300 Subject: [PATCH 2/3] [clang][docs] Add release note for GNU computed `goto` extension fix (#213449) --- clang/docs/ReleaseNotes.md | 2 ++ 1 file changed, 2 insertions(+) diff --git a/clang/docs/ReleaseNotes.md b/clang/docs/ReleaseNotes.md index a38b99ff8e075..a1a8405a2b888 100644 --- a/clang/docs/ReleaseNotes.md +++ b/clang/docs/ReleaseNotes.md @@ -117,6 +117,8 @@ features cannot lower the translation-unit ABI level; #### C++23 Feature Support +- Clang now allows indirect goto statements in `constexpr` functions in C++23 ([P2242R3](https://wg21.link/p2242r3)). (#213449) + #### C++20 Feature Support #### C++17 Feature Support >From be10860f03bd52fcc2f4b1dc22b4fa6d64733229 Mon Sep 17 00:00:00 2001 From: Baba Dan Constantin <[email protected]> Date: Mon, 3 Aug 2026 10:24:22 +0300 Subject: [PATCH 3/3] [clang][constexpr] Move GNU computed goto constexpr test to dedicated file and fix release note --- clang/docs/ReleaseNotes.md | 3 ++- clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p3.cpp | 8 -------- clang/test/SemaCXX/gnu-constexpr-computed-goto.cpp | 12 ++++++++++++ 3 files changed, 14 insertions(+), 9 deletions(-) create mode 100644 clang/test/SemaCXX/gnu-constexpr-computed-goto.cpp diff --git a/clang/docs/ReleaseNotes.md b/clang/docs/ReleaseNotes.md index a1a8405a2b888..8268e5b995c3d 100644 --- a/clang/docs/ReleaseNotes.md +++ b/clang/docs/ReleaseNotes.md @@ -117,7 +117,8 @@ features cannot lower the translation-unit ABI level; #### C++23 Feature Support -- Clang now allows indirect goto statements in `constexpr` functions in C++23 ([P2242R3](https://wg21.link/p2242r3)). (#213449) +- Clang now allows GNU computed `goto` extension in `constexpr` functions, matching the relaxed + `constexpr` function body rules introduced in C++23. #### C++20 Feature Support diff --git a/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p3.cpp b/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p3.cpp index 508941ae0429d..51990ee4341d2 100644 --- a/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p3.cpp +++ b/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p3.cpp @@ -167,14 +167,6 @@ constexpr int DisallowedStmtsCXX14_7() { int n; // beforecxx20-warning {{uninitialized variable in a constexpr function}} } -constexpr int DisallowedStmtsCXX14_8() { - return 0; // beforecxx14-note {{previous}} - // - an indirect goto statement - goto *(&&x); // beforecxx23-warning {{use of this statement in a constexpr function is a C++23 extension}} - x:; - return 0; // beforecxx14-warning {{multiple return}} -} - constexpr int ForStmt() { for (int n = 0; n < 10; ++n) {} // beforecxx14-error {{statement not allowed in constexpr function}} return 0; diff --git a/clang/test/SemaCXX/gnu-constexpr-computed-goto.cpp b/clang/test/SemaCXX/gnu-constexpr-computed-goto.cpp new file mode 100644 index 0000000000000..89d101cbfc48a --- /dev/null +++ b/clang/test/SemaCXX/gnu-constexpr-computed-goto.cpp @@ -0,0 +1,12 @@ +// RUN: %clang_cc1 -fcxx-exceptions -verify=beforecxx14,beforecxx20,beforecxx23 -std=c++11 %s +// RUN: %clang_cc1 -fcxx-exceptions -verify=beforecxx20,beforecxx23 -std=c++14 %s +// RUN: %clang_cc1 -fcxx-exceptions -verify=beforecxx23 -std=c++20 %s +// RUN: %clang_cc1 -fcxx-exceptions -std=c++23 %s + +constexpr int GNUConstexprComputedGoto() { + return 0; // beforecxx14-note {{previous}} + // - an indirect goto statement + goto *(&&x); // beforecxx23-warning {{use of this statement in a constexpr function is a C++23 extension}} + x:; + return 0; // beforecxx14-warning {{multiple return}} +} _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
