[RISCV] Add the RISCV target and compiler driver

As RV64 codegen has not yet been upstreamed into LLVM, we focus on RV32 driver 
support (RV64 to follow).

Differential Revision: https://reviews.llvm.org/D39963

llvm-svn: 322276

7 files changed, 217 insertions, 1 deletions

diff --git a/clang/lib/Driver/CMakeLists.txt b/clang/lib/Driver/CMakeLists.txt
index 5bf91f2be98..afb1cdf3753 100644
--- a/clang/lib/Driver/CMakeLists.txt
+++ b/clang/lib/Driver/CMakeLists.txt
@@ -25,6 +25,7 @@ add_clang_library(clangDriver
   ToolChains/Arch/ARM.cpp
   ToolChains/Arch/Mips.cpp
   ToolChains/Arch/PPC.cpp
+  ToolChains/Arch/RISCV.cpp
   ToolChains/Arch/Sparc.cpp
   ToolChains/Arch/SystemZ.cpp
   ToolChains/Arch/X86.cpp
diff --git a/clang/lib/Driver/ToolChains/Arch/RISCV.cpp b/clang/lib/Driver/ToolChains/Arch/RISCV.cpp
new file mode 100644
index 00000000000..2b4ae88365a
--- /dev/null
+++ b/clang/lib/Driver/ToolChains/Arch/RISCV.cpp
@@ -0,0 +1,61 @@
+//===--- RISCV.cpp - RISCV Helpers for Tools --------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "RISCV.h"
+#include "clang/Driver/Driver.h"
+#include "clang/Driver/DriverDiagnostic.h"
+#include "clang/Driver/Options.h"
+#include "llvm/Option/ArgList.h"
+#include "llvm/Support/TargetParser.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace clang::driver;
+using namespace clang::driver::tools;
+using namespace clang;
+using namespace llvm::opt;
+
+void riscv::getRISCVTargetFeatures(const Driver &D, const ArgList &Args,
+                                   std::vector<StringRef> &Features) {
+  if (const Arg *A = Args.getLastArg(options::OPT_march_EQ)) {
+    StringRef MArch = A->getValue();
+    // TODO: handle rv64
+    std::pair<StringRef, StringRef> MArchSplit = StringRef(MArch).split("rv32");
+    if (!MArchSplit.second.size())
+      return;
+
+    for (char c : MArchSplit.second) {
+      switch (c) {
+      case 'i':
+        break;
+      case 'm':
+        Features.push_back("+m");
+        break;
+      case 'a':
+        Features.push_back("+a");
+        break;
+      case 'f':
+        Features.push_back("+f");
+        break;
+      case 'd':
+        Features.push_back("+d");
+        break;
+      case 'c':
+        Features.push_back("+c");
+        break;
+      }
+    }
+  }
+}
+
+StringRef riscv::getRISCVABI(const ArgList &Args, const llvm::Triple &Triple) {
+  if (Arg *A = Args.getLastArg(options::OPT_mabi_EQ))
+    return A->getValue();
+
+  return Triple.getArch() == llvm::Triple::riscv32 ? "ilp32" : "lp64";
+}
diff --git a/clang/lib/Driver/ToolChains/Arch/RISCV.h b/clang/lib/Driver/ToolChains/Arch/RISCV.h
new file mode 100644
index 00000000000..beda14979fa
--- /dev/null
+++ b/clang/lib/Driver/ToolChains/Arch/RISCV.h
@@ -0,0 +1,32 @@
+//===--- RISCV.h - RISCV-specific Tool Helpers ------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_ARCH_RISCV_H
+#define LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_ARCH_RISCV_H
+
+#include "clang/Driver/Driver.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Option/Option.h"
+#include <string>
+#include <vector>
+
+namespace clang {
+namespace driver {
+namespace tools {
+namespace riscv {
+void getRISCVTargetFeatures(const Driver &D, const llvm::opt::ArgList &Args,
+                            std::vector<llvm::StringRef> &Features);
+StringRef getRISCVABI(const llvm::opt::ArgList &Args,
+                      const llvm::Triple &Triple);
+} // end namespace riscv
+} // namespace tools
+} // end namespace driver
+} // end namespace clang
+
+#endif // LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_ARCH_RISCV_H
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 5c536575da9..3d374a4c6f5 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -12,6 +12,7 @@
 #include "Arch/ARM.h"
 #include "Arch/Mips.h"
 #include "Arch/PPC.h"
+#include "Arch/RISCV.h"
 #include "Arch/Sparc.h"
 #include "Arch/SystemZ.h"
 #include "Arch/X86.h"
@@ -327,6 +328,10 @@ static void getTargetFeatures(const ToolChain &TC, const llvm::Triple &Triple,
   case llvm::Triple::ppc64le:
     ppc::getPPCTargetFeatures(D, Triple, Args, Features);
     break;
+  case llvm::Triple::riscv32:
+  case llvm::Triple::riscv64:
+    riscv::getRISCVTargetFeatures(D, Args, Features);
+    break;
   case llvm::Triple::systemz:
     systemz::getSystemZTargetFeatures(Args, Features);
     break;
@@ -547,6 +552,14 @@ static bool useFramePointerForTargetByDefault(const ArgList &Args,
     }
   }
 
+  switch (Triple.getArch()) {
+    case llvm::Triple::riscv32:
+    case llvm::Triple::riscv64:
+      return !areOptimizationsEnabled(Args);
+    default:
+      break;
+  }
+
   if (Triple.isOSWindows()) {
     switch (Triple.getArch()) {
     case llvm::Triple::x86:
@@ -1282,6 +1295,8 @@ static bool isSignedCharDefault(const llvm::Triple &Triple) {
 
   case llvm::Triple::hexagon:
   case llvm::Triple::ppc64le:
+  case llvm::Triple::riscv32:
+  case llvm::Triple::riscv64:
   case llvm::Triple::systemz:
   case llvm::Triple::xcore:
     return false;
@@ -1391,6 +1406,11 @@ void Clang::RenderTargetOptions(const llvm::Triple &EffectiveTriple,
     AddPPCTargetArgs(Args, CmdArgs);
     break;
 
+  case llvm::Triple::riscv32:
+  case llvm::Triple::riscv64:
+    AddRISCVTargetArgs(Args, CmdArgs);
+    break;
+
   case llvm::Triple::sparc:
   case llvm::Triple::sparcel:
   case llvm::Triple::sparcv9:
@@ -1668,6 +1688,25 @@ void Clang::AddPPCTargetArgs(const ArgList &Args,
   }
 }
 
+void Clang::AddRISCVTargetArgs(const ArgList &Args,
+                               ArgStringList &CmdArgs) const {
+  // FIXME: currently defaults to the soft-float ABIs. Will need to be
+  // expanded to select ilp32f, ilp32d, lp64f, lp64d when appropiate.
+  const char *ABIName = nullptr;
+  const llvm::Triple &Triple = getToolChain().getTriple();
+  if (Arg *A = Args.getLastArg(options::OPT_mabi_EQ))
+    ABIName = A->getValue();
+  else if (Triple.getArch() == llvm::Triple::riscv32)
+    ABIName = "ilp32";
+  else if (Triple.getArch() == llvm::Triple::riscv64)
+    ABIName = "lp64";
+  else
+    llvm_unreachable("Unexpected triple!");
+
+  CmdArgs.push_back("-target-abi");
+  CmdArgs.push_back(ABIName);
+}
+
 void Clang::AddSparcTargetArgs(const ArgList &Args,
                                ArgStringList &CmdArgs) const {
   sparc::FloatABI FloatABI =
diff --git a/clang/lib/Driver/ToolChains/Clang.h b/clang/lib/Driver/ToolChains/Clang.h
index e23822b9c67..8893d88a8ca 100644
--- a/clang/lib/Driver/ToolChains/Clang.h
+++ b/clang/lib/Driver/ToolChains/Clang.h
@@ -60,6 +60,8 @@ private:
                         llvm::opt::ArgStringList &CmdArgs) const;
   void AddR600TargetArgs(const llvm::opt::ArgList &Args,
                          llvm::opt::ArgStringList &CmdArgs) const;
+  void AddRISCVTargetArgs(const llvm::opt::ArgList &Args,
+                          llvm::opt::ArgStringList &CmdArgs) const;
   void AddSparcTargetArgs(const llvm::opt::ArgList &Args,
                           llvm::opt::ArgStringList &CmdArgs) const;
   void AddSystemZTargetArgs(const llvm::opt::ArgList &Args,
diff --git a/clang/lib/Driver/ToolChains/Gnu.cpp b/clang/lib/Driver/ToolChains/Gnu.cpp
index 7845781f12c..d7cc101a60f 100644
--- a/clang/lib/Driver/ToolChains/Gnu.cpp
+++ b/clang/lib/Driver/ToolChains/Gnu.cpp
@@ -8,13 +8,14 @@
 //===----------------------------------------------------------------------===//
 
 #include "Gnu.h"
-#include "Linux.h"
 #include "Arch/ARM.h"
 #include "Arch/Mips.h"
 #include "Arch/PPC.h"
+#include "Arch/RISCV.h"
 #include "Arch/Sparc.h"
 #include "Arch/SystemZ.h"
 #include "CommonArgs.h"
+#include "Linux.h"
 #include "clang/Basic/VirtualFileSystem.h"
 #include "clang/Config/config.h" // for GCC_INSTALL_PREFIX
 #include "clang/Driver/Compilation.h"
@@ -271,6 +272,10 @@ static const char *getLDMOption(const llvm::Triple &T, const ArgList &Args) {
     return "elf64ppc";
   case llvm::Triple::ppc64le:
     return "elf64lppc";
+  case llvm::Triple::riscv32:
+    return "elf32lriscv";
+  case llvm::Triple::riscv64:
+    return "elf64lriscv";
   case llvm::Triple::sparc:
   case llvm::Triple::sparcel:
     return "elf32_sparc";
@@ -856,6 +861,10 @@ static bool isMicroMips(const ArgList &Args) {
   return A && A->getOption().matches(options::OPT_mmicromips);
 }
 
+static bool isRISCV(llvm::Triple::ArchType Arch) {
+  return Arch == llvm::Triple::riscv32 || Arch == llvm::Triple::riscv64;
+}
+
 static Multilib makeMultilib(StringRef commonSuffix) {
   return Multilib(commonSuffix, commonSuffix, commonSuffix);
 }
@@ -1401,6 +1410,41 @@ static void findAndroidArmMultilibs(const Driver &D,
     Result.Multilibs = AndroidArmMultilibs;
 }
 
+static void findRISCVMultilibs(const Driver &D,
+                               const llvm::Triple &TargetTriple, StringRef Path,
+                               const ArgList &Args, DetectedMultilibs &Result) {
+
+  FilterNonExistent NonExistent(Path, "/crtbegin.o", D.getVFS());
+  Multilib Ilp32 = makeMultilib("lib32/ilp32").flag("+m32").flag("+mabi=ilp32");
+  Multilib Ilp32f =
+      makeMultilib("lib32/ilp32f").flag("+m32").flag("+mabi=ilp32f");
+  Multilib Ilp32d =
+      makeMultilib("lib32/ilp32d").flag("+m32").flag("+mabi=ilp32d");
+  Multilib Lp64 = makeMultilib("lib64/lp64").flag("+m64").flag("+mabi=lp64");
+  Multilib Lp64f = makeMultilib("lib64/lp64f").flag("+m64").flag("+mabi=lp64f");
+  Multilib Lp64d = makeMultilib("lib64/lp64d").flag("+m64").flag("+mabi=lp64d");
+  MultilibSet RISCVMultilibs =
+      MultilibSet()
+          .Either({Ilp32, Ilp32f, Ilp32d, Lp64, Lp64f, Lp64d})
+          .FilterOut(NonExistent);
+
+  Multilib::flags_list Flags;
+  bool IsRV64 = TargetTriple.getArch() == llvm::Triple::riscv64;
+  StringRef ABIName = tools::riscv::getRISCVABI(Args, TargetTriple);
+
+  addMultilibFlag(!IsRV64, "m32", Flags);
+  addMultilibFlag(IsRV64, "m64", Flags);
+  addMultilibFlag(ABIName == "ilp32", "mabi=ilp32", Flags);
+  addMultilibFlag(ABIName == "ilp32f", "mabi=ilp32f", Flags);
+  addMultilibFlag(ABIName == "ilp32d", "mabi=ilp32d", Flags);
+  addMultilibFlag(ABIName == "lp64", "mabi=lp64", Flags);
+  addMultilibFlag(ABIName == "lp64f", "mabi=lp64f", Flags);
+  addMultilibFlag(ABIName == "lp64d", "mabi=lp64d", Flags);
+
+  if (RISCVMultilibs.select(Flags, Result.SelectedMultilib))
+    Result.Multilibs = RISCVMultilibs;
+}
+
 static bool findBiarchMultilibs(const Driver &D,
                                 const llvm::Triple &TargetTriple,
                                 StringRef Path, const ArgList &Args,
@@ -1783,6 +1827,10 @@ bool Generic_GCC::GCCInstallationDetector::getBiarchSibling(Multilib &M) const {
       "powerpc64le-linux-gnu", "powerpc64le-unknown-linux-gnu",
       "powerpc64le-suse-linux", "ppc64le-redhat-linux"};
 
+  static const char *const RISCV32LibDirs[] = {"/lib", "/lib32"};
+  static const char *const RISCVTriples[] = {"riscv32-unknown-linux-gnu",
+                                             "riscv64-unknown-linux-gnu"};
+
   static const char *const SPARCv8LibDirs[] = {"/lib32", "/lib"};
   static const char *const SPARCv8Triples[] = {"sparc-linux-gnu",
                                                "sparcv8-linux-gnu"};
@@ -1928,6 +1976,12 @@ bool Generic_GCC::GCCInstallationDetector::getBiarchSibling(Multilib &M) const {
     LibDirs.append(begin(PPC64LELibDirs), end(PPC64LELibDirs));
     TripleAliases.append(begin(PPC64LETriples), end(PPC64LETriples));
     break;
+  case llvm::Triple::riscv32:
+    LibDirs.append(begin(RISCV32LibDirs), end(RISCV32LibDirs));
+    BiarchLibDirs.append(begin(RISCV32LibDirs), end(RISCV32LibDirs));
+    TripleAliases.append(begin(RISCVTriples), end(RISCVTriples));
+    BiarchTripleAliases.append(begin(RISCVTriples), end(RISCVTriples));
+    break;
   case llvm::Triple::sparc:
   case llvm::Triple::sparcel:
     LibDirs.append(begin(SPARCv8LibDirs), end(SPARCv8LibDirs));
@@ -2025,6 +2079,8 @@ bool Generic_GCC::GCCInstallationDetector::ScanGCCForMultilibs(
   } else if (tools::isMipsArch(TargetArch)) {
     if (!findMIPSMultilibs(D, TargetTriple, Path, Args, Detected))
       return false;
+  } else if (isRISCV(TargetArch)) {
+    findRISCVMultilibs(D, TargetTriple, Path, Args, Detected);
   } else if (!findBiarchMultilibs(D, TargetTriple, Path, Args,
                                   NeedsBiarchSuffix, Detected)) {
     return false;
@@ -2240,6 +2296,8 @@ bool Generic_GCC::IsIntegratedAssemblerDefault() const {
   case llvm::Triple::ppc:
   case llvm::Triple::ppc64:
   case llvm::Triple::ppc64le:
+  case llvm::Triple::riscv32:
+  case llvm::Triple::riscv64:
   case llvm::Triple::systemz:
   case llvm::Triple::mips:
   case llvm::Triple::mipsel:
diff --git a/clang/lib/Driver/ToolChains/Linux.cpp b/clang/lib/Driver/ToolChains/Linux.cpp
index 1301cdf114a..9ce2407d991 100644
--- a/clang/lib/Driver/ToolChains/Linux.cpp
+++ b/clang/lib/Driver/ToolChains/Linux.cpp
@@ -11,6 +11,7 @@
 #include "Arch/ARM.h"
 #include "Arch/Mips.h"
 #include "Arch/PPC.h"
+#include "Arch/RISCV.h"
 #include "CommonArgs.h"
 #include "clang/Basic/VirtualFileSystem.h"
 #include "clang/Config/config.h"
@@ -176,6 +177,9 @@ static StringRef getOSLibDir(const llvm::Triple &Triple, const ArgList &Args) {
       Triple.getEnvironment() == llvm::Triple::GNUX32)
     return "libx32";
 
+  if (Triple.getArch() == llvm::Triple::riscv32)
+    return "lib32";
+
   return Triple.isArch32Bit() ? "lib" : "lib64";
 }
 
@@ -226,6 +230,8 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
   const bool IsAndroid = Triple.isAndroid();
   const bool IsMips = tools::isMipsArch(Arch);
   const bool IsHexagon = Arch == llvm::Triple::hexagon;
+  const bool IsRISCV =
+      Arch == llvm::Triple::riscv32 || Arch == llvm::Triple::riscv64;
 
   if (IsMips && !SysRoot.empty())
     ExtraOpts.push_back("--sysroot=" + SysRoot);
@@ -333,6 +339,11 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
   addPathIfExists(D, SysRoot + "/lib/../" + OSLibDir, Paths);
   addPathIfExists(D, SysRoot + "/usr/lib/" + MultiarchTriple, Paths);
   addPathIfExists(D, SysRoot + "/usr/lib/../" + OSLibDir, Paths);
+  if (IsRISCV) {
+    StringRef ABIName = tools::riscv::getRISCVABI(Args, Triple);
+    addPathIfExists(D, SysRoot + "/" + OSLibDir + "/" + ABIName, Paths);
+    addPathIfExists(D, SysRoot + "/usr/" + OSLibDir + "/" + ABIName, Paths);
+  }
 
   // Try walking via the GCC triple path in case of biarch or multiarch GCC
   // installations with strange symlinks.
@@ -511,6 +522,18 @@ std::string Linux::getDynamicLinker(const ArgList &Args) const {
     Loader =
         (tools::ppc::hasPPCAbiArg(Args, "elfv1")) ? "ld64.so.1" : "ld64.so.2";
     break;
+  case llvm::Triple::riscv32: {
+    StringRef ABIName = tools::riscv::getRISCVABI(Args, Triple);
+    LibDir = "lib";
+    Loader = ("ld-linux-riscv32-" + ABIName + ".so.1").str();
+    break;
+  }
+  case llvm::Triple::riscv64: {
+    StringRef ABIName = tools::riscv::getRISCVABI(Args, Triple);
+    LibDir = "lib";
+    Loader = ("ld-linux-riscv64-" + ABIName + ".so.1").str();
+    break;
+  }
   case llvm::Triple::sparc:
   case llvm::Triple::sparcel:
     LibDir = "lib";