[LFI] Introduce AArch64 LFI Target

clang/lib/Basic/Targets/AArch64.cpp

@@ -412,6 +412,9 @@ void AArch64TargetInfo::getTargetDefines(const LangOptions &Opts,
     Builder.defineMacro("__aarch64__");
   }
 
+  if (getTriple().isLFI())
+    Builder.defineMacro("__LFI__");
+
   // Inline assembly supports AArch64 flag outputs.
   Builder.defineMacro("__GCC_ASM_FLAG_OUTPUTS__");
 

clang/lib/Driver/CMakeLists.txt

@@ -63,6 +63,7 @@ add_clang_library(clangDriver
   ToolChains/Hexagon.cpp
   ToolChains/HLSL.cpp
   ToolChains/Hurd.cpp
+  ToolChains/LFILinux.cpp
   ToolChains/Linux.cpp
   ToolChains/Managarm.cpp
   ToolChains/MipsLinux.cpp

clang/lib/Driver/Driver.cpp

@@ -29,6 +29,7 @@
 #include "ToolChains/Haiku.h"
 #include "ToolChains/Hexagon.h"
 #include "ToolChains/Hurd.h"
+#include "ToolChains/LFILinux.h"
 #include "ToolChains/Lanai.h"
 #include "ToolChains/Linux.h"
 #include "ToolChains/MSP430.h"
@@ -6864,6 +6865,9 @@ const ToolChain &Driver::getToolChain(const ArgList &Args,
         TC = std::make_unique<toolchains::OHOS>(*this, Target, Args);
       else if (Target.isWALI())
         TC = std::make_unique<toolchains::WebAssembly>(*this, Target, Args);
+      else if (Target.isLFI())
+        TC = std::make_unique<toolchains::LFILinuxToolChain>(*this, Target,
+                                                             Args);
       else
         TC = std::make_unique<toolchains::Linux>(*this, Target, Args);
       break;

clang/lib/Driver/ToolChains/LFILinux.cpp

@@ -0,0 +1,27 @@
+//===-- LFILinux.cpp - LFI ToolChain Implementations ------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "LFILinux.h"
+
+using namespace clang::driver::toolchains;
+using namespace llvm::opt;
+
+void LFILinuxToolChain::AddCXXStdlibLibArgs(const ArgList &Args,
+                                            ArgStringList &CmdArgs) const {
+  switch (GetCXXStdlibType(Args)) {
+  case ToolChain::CST_Libcxx:
+    CmdArgs.push_back("-lc++");
+    if (Args.hasArg(options::OPT_fexperimental_library))
+      CmdArgs.push_back("-lc++experimental");
+    CmdArgs.push_back("-lc++abi");
+    break;
+  case ToolChain::CST_Libstdcxx:
+    CmdArgs.push_back("-lstdc++");
+    break;
+  }
+}

clang/lib/Driver/ToolChains/LFILinux.h

@@ -0,0 +1,35 @@
+//===--- LFILinux.h - LFI ToolChain Implementations -------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_LFI_LINUX_H
+#define LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_LFI_LINUX_H
+
+#include "Linux.h"
+
+namespace clang {
+namespace driver {
+namespace toolchains {
+
+class LLVM_LIBRARY_VISIBILITY LFILinuxToolChain : public Linux {
+public:
+  LFILinuxToolChain(const Driver &D, const llvm::Triple &Triple,
+                    const llvm::opt::ArgList &Args)
+      : Linux(D, Triple, Args) {
+    ExtraOpts.push_back("-z");
+    ExtraOpts.push_back("separate-code");
+  }
+
+  void AddCXXStdlibLibArgs(const llvm::opt::ArgList &Args,
+                           llvm::opt::ArgStringList &CmdArgs) const override;
+};
+
+} // end namespace toolchains
+} // end namespace driver
+} // end namespace clang
+
+#endif // LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_LFI_LINUX_H

compiler-rt/cmake/builtin-config-ix.cmake

@@ -78,7 +78,7 @@ else()
 endif()
 
 set(AMDGPU amdgcn)
-set(ARM64 aarch64 arm64ec)
+set(ARM64 aarch64 arm64ec aarch64_lfi)
 set(ARM32 arm armhf armv4t armv5te armv6 armv6m armv7m armv7em armv7 armv7s armv7k armv8m.base armv8m.main armv8.1m.main)
 set(AVR avr)
 set(HEXAGON hexagon)

compiler-rt/lib/builtins/CMakeLists.txt

@@ -692,6 +692,7 @@ set(arm64_SOURCES ${aarch64_SOURCES})
 set(arm64e_SOURCES ${aarch64_SOURCES})
 set(arm64_32_SOURCES ${aarch64_SOURCES})
 set(arm64ec_SOURCES ${aarch64_SOURCES})
+set(aarch64_lfi_SOURCES ${aarch64_SOURCES})
 
 # macho_embedded archs
 set(armv6m_SOURCES ${thumb1_SOURCES})

llvm/docs/CodeGenerator.rst

@@ -2492,3 +2492,10 @@ The AMDGPU backend
 The AMDGPU code generator lives in the ``lib/Target/AMDGPU``
 directory. This code generator is capable of targeting a variety of
 AMD GPU processors. Refer to :doc:`AMDGPUUsage` for more information.
+
+The Lightweight Fault Isolation (LFI) backend
+---------------------------------------------
+
+LFI is a backend that allows programs compiled for the target to run in a
+sandboxed environment that is within the same address space as host code. Refer
+to :doc:`LFI` for more information about the LFI backend.