From a53551a7f5896106e856c32dceecf83c126607f6 Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Mon, 27 Nov 2017 21:39:16 +0000 Subject: [PATCH] [WebAssemby] Enable "-mthread-model single" by default, for now. The WebAssembly standard does not yet have threads, and while it's in the process of being standardized, it'll take some time for it to make it through and be available in all popular implementations. With increasing numbers of people using the LLVM wasm backend through LLVM directly rather than through Emscripten, it's increasingly important to have friendly defaults. See also https://bugs.llvm.org/show_bug.cgi?id=35411 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@319101 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Driver/ToolChains/WebAssembly.cpp | 8 ++++++++ lib/Driver/ToolChains/WebAssembly.h | 1 + 2 files changed, 9 insertions(+) diff --git a/lib/Driver/ToolChains/WebAssembly.cpp b/lib/Driver/ToolChains/WebAssembly.cpp index 1464c150c9..d00d833fbb 100644 --- a/lib/Driver/ToolChains/WebAssembly.cpp +++ b/lib/Driver/ToolChains/WebAssembly.cpp @@ -135,6 +135,14 @@ void WebAssembly::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs, getDriver().SysRoot + "/include/c++/v1"); } +std::string WebAssembly::getThreadModel() const { + // The WebAssembly MVP does not yet support threads; for now, use the + // "single" threading model, which lowers atomics to non-atomic operations. + // When threading support is standardized and implemented in popular engines, + // this override should be removed. + return "single"; +} + Tool *WebAssembly::buildLinker() const { return new tools::wasm::Linker(*this); } diff --git a/lib/Driver/ToolChains/WebAssembly.h b/lib/Driver/ToolChains/WebAssembly.h index 7524361d51..8784e12dfb 100644 --- a/lib/Driver/ToolChains/WebAssembly.h +++ b/lib/Driver/ToolChains/WebAssembly.h @@ -62,6 +62,7 @@ private: void AddClangCXXStdlibIncludeArgs( const llvm::opt::ArgList &DriverArgs, llvm::opt::ArgStringList &CC1Args) const override; + std::string getThreadModel() const override; const char *getDefaultLinker() const override { return "lld"; -- 2.50.1