From add16a8da9ccd07eabda2dffd0d32188f07da09c Mon Sep 17 00:00:00 2001 From: Eric Fiselier Date: Wed, 24 Apr 2019 02:23:30 +0000 Subject: [Builtins] Implement __builtin_is_constant_evaluated for use in C++2a Summary: This patch implements `__builtin_is_constant_evaluated` as specifier by [P0595R2](https://wg21.link/p0595r2). It is built on the back of Bill Wendling's work for `__builtin_constant_p()`. More tests to come, but early feedback is appreciated. I plan to implement warnings for common mis-usages like those belowe in a following patch: ``` void foo(int x) { if constexpr (std::is_constant_evaluated())) { // condition is always `true`. Should use plain `if` instead. foo_constexpr(x); } else { foo_runtime(x); } } ``` Reviewers: rsmith, MaskRay, bruno, void Reviewed By: rsmith Subscribers: dexonsmith, zoecarver, fdeazeve, kristina, cfe-commits Differential Revision: https://reviews.llvm.org/D55500 llvm-svn: 359067 --- clang/lib/Basic/Builtins.cpp | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'clang/lib/Basic/Builtins.cpp') diff --git a/clang/lib/Basic/Builtins.cpp b/clang/lib/Basic/Builtins.cpp index f04bc1f216b..cfc5927774a 100644 --- a/clang/lib/Basic/Builtins.cpp +++ b/clang/lib/Basic/Builtins.cpp @@ -75,9 +75,12 @@ bool Builtin::Context::builtinIsSupported(const Builtin::Info &BuiltinInfo, bool OclCUnsupported = !LangOpts.OpenCL && (BuiltinInfo.Langs & ALL_OCLC_LANGUAGES); bool OpenMPUnsupported = !LangOpts.OpenMP && BuiltinInfo.Langs == OMP_LANG; + bool CPlusPlusUnsupported = + !LangOpts.CPlusPlus && BuiltinInfo.Langs == CXX_LANG; return !BuiltinsUnsupported && !MathBuiltinsUnsupported && !OclCUnsupported && !OclC1Unsupported && !OclC2Unsupported && !OpenMPUnsupported && - !GnuModeUnsupported && !MSModeUnsupported && !ObjCUnsupported; + !GnuModeUnsupported && !MSModeUnsupported && !ObjCUnsupported && + !CPlusPlusUnsupported; } /// initializeBuiltins - Mark the identifiers for all the builtins with their -- cgit v1.2.3