Author: djg Date: Mon Nov 27 13:39:16 2017 New Revision: 319101 URL: http://llvm.org/viewvc/llvm-project?rev=319101&view=rev Log: [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 Modified: cfe/trunk/lib/Driver/ToolChains/WebAssembly.cpp cfe/trunk/lib/Driver/ToolChains/WebAssembly.h Modified: cfe/trunk/lib/Driver/ToolChains/WebAssembly.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/ToolChains/WebAssembly.cpp?rev=319101&r1=319100&r2=319101&view=diff ============================================================================== --- cfe/trunk/lib/Driver/ToolChains/WebAssembly.cpp (original) +++ cfe/trunk/lib/Driver/ToolChains/WebAssembly.cpp Mon Nov 27 13:39:16 2017 @@ -135,6 +135,14 @@ void WebAssembly::AddClangCXXStdlibInclu 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); } Modified: cfe/trunk/lib/Driver/ToolChains/WebAssembly.h URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/ToolChains/WebAssembly.h?rev=319101&r1=319100&r2=319101&view=diff ============================================================================== --- cfe/trunk/lib/Driver/ToolChains/WebAssembly.h (original) +++ cfe/trunk/lib/Driver/ToolChains/WebAssembly.h Mon Nov 27 13:39:16 2017 @@ -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"; _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits