Author: Paul Kirth Date: 2023-04-10T17:43:49Z New Revision: a78816a6b6debb548efbf1717aeeb490df42f401
URL: https://github.com/llvm/llvm-project/commit/a78816a6b6debb548efbf1717aeeb490df42f401 DIFF: https://github.com/llvm/llvm-project/commit/a78816a6b6debb548efbf1717aeeb490df42f401.diff LOG: [clang][driver] Pass `-femulated-tls` through to the linker in LTO mode Currently the driver does not propagate the `-f[no-]emulated-tls` flags to the linker under LTO. This can be surprising when the platform defaults differ from the flags being passed. A related discussion can be found in https://reviews.llvm.org/D143619. While the focus there was RISC-V support, the root cause was that setting `-femualted-tls` and `-flto` when compiling with Clang resulted in missing symbols because the platform defaults for Android differed from the flags being passed to Clang. This patch changes the Clang driver's behavior to pass the emulated-tls flags through to the linker when compiling with LTO/ThinLTO. Reviewed By: phosek, vit9696 Differential Revision: https://reviews.llvm.org/D147834 Added: Modified: clang/lib/Driver/ToolChains/CommonArgs.cpp clang/test/Driver/emulated-tls.cpp Removed: ################################################################################ diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp index 6190c9d65ddb..2f3450432ba2 100644 --- a/clang/lib/Driver/ToolChains/CommonArgs.cpp +++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp @@ -764,6 +764,13 @@ void tools::addLTOOptions(const ToolChain &ToolChain, const ArgList &Args, D.Diag(clang::diag::warn_drv_fjmc_for_elf_only); } + if (Arg *A = Args.getLastArg(options::OPT_femulated_tls, + options::OPT_fno_emulated_tls)) { + bool Enable = A->getOption().getID() == options::OPT_femulated_tls; + CmdArgs.push_back(Args.MakeArgString( + Twine(PluginOptPrefix) + "-emulated-tls=" + (Enable ? "1" : "0"))); + } + if (Args.hasFlag(options::OPT_fstack_size_section, options::OPT_fno_stack_size_section, false)) CmdArgs.push_back( diff --git a/clang/test/Driver/emulated-tls.cpp b/clang/test/Driver/emulated-tls.cpp index 20abad181128..edc68e0f29f5 100644 --- a/clang/test/Driver/emulated-tls.cpp +++ b/clang/test/Driver/emulated-tls.cpp @@ -29,6 +29,16 @@ // RUN: %clang -### -target i686-pc-openbsd %s -femulated-tls -fno-emulated-tls 2>&1 \ // RUN: | FileCheck -check-prefix=NOEMU %s +// Test that when lto is used any -emualted-tls flags are passed to the linker +// LINUX and Android have diff erent defaults for EmulatedTLS +// RUN: %clang -### -flto --target=riscv64-linux -fno-emulated-tls %s 2>&1 \ +// RUN: | FileCheck %s --check-prefix=LTO_NOEMUTLS +// RUN: %clang -### -flto --target=riscv64-linux-android10000 -femulated-tls %s 2>&1 \ +// RUN: | FileCheck %s --check-prefix=LTO_EMUTLS +// RUN: %clang -### -flto --target=riscv64-linux -femulated-tls %s 2>&1 \ +// RUN: | FileCheck %s --check-prefix=LTO_EMUTLS +// RUN: %clang -### -flto --target=riscv64-linux-android10000 -fno-emulated-tls %s 2>&1 \ +// RUN: | FileCheck %s --check-prefix=LTO_NOEMUTLS // Default without -f[no-]emulated-tls, will be decided by the target triple. // DEFAULT-NOT: "-cc1" {{.*}}"-femulated-tls" @@ -40,3 +50,10 @@ // NOEMU: "-cc1" {{.*}}"-fno-emulated-tls" // NOEMU-NOT: "-cc1" {{.*}}"-femulated-tls" + +// LTO related checks +// LTO_NOEMUTLS: plugin-opt=-emulated-tls=0 +// LTO_NOEMUTLS-NOT: plugin-opt=-emulated-tls=1 + +// LTO_EMUTLS: plugin-opt=-emulated-tls=1 +// LTO_EMUTLS-NOT: plugin-opt=-emulated-tls=0 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
