From 7f569b7c4f39881a1e4843f4f44ae413e67da65b Mon Sep 17 00:00:00 2001 From: Kristina Brooks Date: Thu, 18 Oct 2018 14:07:02 +0000 Subject: [PATCH] Add support for -mno-tls-direct-seg-refs to Clang This patch exposes functionality added in rL344723 to the Clang driver/frontend as a flag and adds appropriate metadata. Driver tests pass: ``` ninja check-clang-driver -snip- Expected Passes : 472 Expected Failures : 3 Unsupported Tests : 65 ``` Odd failure in CodeGen tests but unrelated to this: ``` ninja check-clang-codegen -snip- /SourceCache/llvm-trunk-8.0/tools/clang/test/CodeGen/builtins-wasm.c:87:10: error: cannot compile this builtin function yet -snip- Failing Tests (1): Clang :: CodeGen/builtins-wasm.c Expected Passes : 1250 Expected Failures : 2 Unsupported Tests : 120 Unexpected Failures: 1 ``` Original commit: [X86] Support for the mno-tls-direct-seg-refs flag Allows to disable direct TLS segment access (%fs or %gs). GCC supports a similar flag, it can be useful in some circumstances, e.g. when a thread context block needs to be updated directly from user space. More info and specific use cases: https://bugs.llvm.org/show_bug.cgi?id=16145 Patch by nruslan (Ruslan Nikolaev). Differential Revision: https://reviews.llvm.org/D53102 llvm-svn: 344739 --- clang/include/clang/Driver/Options.td | 4 ++++ clang/include/clang/Frontend/CodeGenOptions.def | 2 ++ clang/lib/CodeGen/CGCall.cpp | 2 ++ clang/lib/Driver/ToolChains/Clang.cpp | 4 ++++ clang/lib/Frontend/CompilerInvocation.cpp | 1 + clang/test/CodeGen/indirect-tls-seg-refs.c | 8 ++++++++ clang/test/Driver/indirect-tls-seg-refs.c | 7 +++++++ 7 files changed, 28 insertions(+) create mode 100644 clang/test/CodeGen/indirect-tls-seg-refs.c create mode 100644 clang/test/Driver/indirect-tls-seg-refs.c diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td index bc2d935..ca65428 100644 --- a/clang/include/clang/Driver/Options.td +++ b/clang/include/clang/Driver/Options.td @@ -2011,6 +2011,8 @@ def mno_global_merge : Flag<["-"], "mno-global-merge">, Group, Flags<[C def mno_pascal_strings : Flag<["-"], "mno-pascal-strings">, Alias; def mno_red_zone : Flag<["-"], "mno-red-zone">, Group; +def mno_tls_direct_seg_refs : Flag<["-"], "mno-tls-direct-seg-refs">, Group, Flags<[CC1Option]>, + HelpText<"Disable direct TLS access through segment registers">; def mno_relax_all : Flag<["-"], "mno-relax-all">, Group; def mno_rtd: Flag<["-"], "mno-rtd">, Group; def mno_soft_float : Flag<["-"], "mno-soft-float">, Group; @@ -2171,6 +2173,8 @@ def momit_leaf_frame_pointer : Flag<["-"], "momit-leaf-frame-pointer">, Group, Alias; def mred_zone : Flag<["-"], "mred-zone">, Group; +def mtls_direct_seg_refs : Flag<["-"], "mtls-direct-seg-refs">, Group, + HelpText<"Enable direct TLS access through segment registers (default)">; def mregparm_EQ : Joined<["-"], "mregparm=">, Group; def mrelax_all : Flag<["-"], "mrelax-all">, Group, Flags<[CC1Option,CC1AsOption]>, HelpText<"(integrated-as) Relax all machine instructions">; diff --git a/clang/include/clang/Frontend/CodeGenOptions.def b/clang/include/clang/Frontend/CodeGenOptions.def index f94979c..74193ab 100644 --- a/clang/include/clang/Frontend/CodeGenOptions.def +++ b/clang/include/clang/Frontend/CodeGenOptions.def @@ -62,6 +62,8 @@ CODEGENOPT(ExperimentalNewPassManager, 1, 0) ///< Enables the new, experimental CODEGENOPT(DebugPassManager, 1, 0) ///< Prints debug information for the new ///< pass manager. CODEGENOPT(DisableRedZone , 1, 0) ///< Set when -mno-red-zone is enabled. +CODEGENOPT(IndirectTlsSegRefs, 1, 0) ///< Set when -mno-tls-direct-seg-refs + ///< is specified. CODEGENOPT(DisableTailCalls , 1, 0) ///< Do not emit tail calls. CODEGENOPT(NoEscapingBlockTailCalls, 1, 0) ///< Do not emit tail calls from ///< escaping blocks. diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp index 8857ffd..8edf7f4 100644 --- a/clang/lib/CodeGen/CGCall.cpp +++ b/clang/lib/CodeGen/CGCall.cpp @@ -1709,6 +1709,8 @@ void CodeGenModule::ConstructDefaultFnAttrList(StringRef Name, bool HasOptnone, if (CodeGenOpts.DisableRedZone) FuncAttrs.addAttribute(llvm::Attribute::NoRedZone); + if (CodeGenOpts.IndirectTlsSegRefs) + FuncAttrs.addAttribute("indirect-tls-seg-refs"); if (CodeGenOpts.NoImplicitFloat) FuncAttrs.addAttribute(llvm::Attribute::NoImplicitFloat); diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp index 322a02d..e15c9ad 100644 --- a/clang/lib/Driver/ToolChains/Clang.cpp +++ b/clang/lib/Driver/ToolChains/Clang.cpp @@ -1739,6 +1739,10 @@ void Clang::AddX86TargetArgs(const ArgList &Args, Args.hasArg(options::OPT_fapple_kext)) CmdArgs.push_back("-disable-red-zone"); + if (!Args.hasFlag(options::OPT_mtls_direct_seg_refs, + options::OPT_mno_tls_direct_seg_refs, true)) + CmdArgs.push_back("-mno-tls-direct-seg-refs"); + // Default to avoid implicit floating-point for kernel/kext code, but allow // that to be overridden with -mno-soft-float. bool NoImplicitFloat = (Args.hasArg(options::OPT_mkernel) || diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp index 5dcd23e..267b347 100644 --- a/clang/lib/Frontend/CompilerInvocation.cpp +++ b/clang/lib/Frontend/CompilerInvocation.cpp @@ -614,6 +614,7 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK, Opts.DisableLifetimeMarkers = Args.hasArg(OPT_disable_lifetimemarkers); Opts.DisableO0ImplyOptNone = Args.hasArg(OPT_disable_O0_optnone); Opts.DisableRedZone = Args.hasArg(OPT_disable_red_zone); + Opts.IndirectTlsSegRefs = Args.hasArg(OPT_mno_tls_direct_seg_refs); Opts.ForbidGuardVariables = Args.hasArg(OPT_fforbid_guard_variables); Opts.UseRegisterSizedBitfieldAccess = Args.hasArg( OPT_fuse_register_sized_bitfield_access); diff --git a/clang/test/CodeGen/indirect-tls-seg-refs.c b/clang/test/CodeGen/indirect-tls-seg-refs.c new file mode 100644 index 0000000..2680680 --- /dev/null +++ b/clang/test/CodeGen/indirect-tls-seg-refs.c @@ -0,0 +1,8 @@ +// RUN: %clang_cc1 %s -emit-llvm -o - -mno-tls-direct-seg-refs | FileCheck %s -check-prefix=NO-TLSDIRECT +// RUN: %clang_cc1 %s -emit-llvm -o - | FileCheck %s -check-prefix=TLSDIRECT + +// NO-TLSDIRECT: attributes #{{[0-9]+}} = {{{.*}} "indirect-tls-seg-refs" +// TLSDIRECT-NOT: attributes #{{[0-9]+}} = {{{.*}} "indirect-tls-seg-refs" + +void test1() { +} diff --git a/clang/test/Driver/indirect-tls-seg-refs.c b/clang/test/Driver/indirect-tls-seg-refs.c new file mode 100644 index 0000000..e15e874 --- /dev/null +++ b/clang/test/Driver/indirect-tls-seg-refs.c @@ -0,0 +1,7 @@ +// RUN: %clang -### %s 2>&1 | FileCheck %s -check-prefix=TLSDIRECT +// RUN: %clang -### -mno-tls-direct-seg-refs -mtls-direct-seg-refs %s 2>&1 | FileCheck %s -check-prefix=TLSDIRECT +// RUN: %clang -### -mtls-direct-seg-refs -mno-tls-direct-seg-refs %s 2>&1 | FileCheck %s -check-prefix=NO-TLSDIRECT +// REQUIRES: clang-driver + +// NO-TLSDIRECT: -mno-tls-direct-seg-refs +// TLSDIRECT-NOT: -mno-tls-direct-seg-refs -- 2.7.4