[RISCV] Add driver for riscv32-unknown-elf baremetal target

Summary:
This patch adds a driver for the baremetal RISC-V target (i.e. riscv32-unknown-elf). For reference, D39963 added basic target info and added support for riscv32-linux-unknown-elf.

Patch by: asb (Alex Bradbury)

Reviewers: efriedma, phosek, apazos, espindola, mgrang

Reviewed By: mgrang

Subscribers: jrtc27, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, emaste, mgorny, arichardson, rbar, johnrusso, simoncook, jordy.potman.lists, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, mgrang, cfe-commits

Differential Revision: https://reviews.llvm.org/D46822

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@338385 91177308-0d34-0410-b5e6-96231b3b80d8

11 files changed, 213 insertions, 1 deletions

diff --git a/lib/Driver/CMakeLists.txt b/lib/Driver/CMakeLists.txt
index 471ffe0f1b..2b03c9f700 100644
--- a/lib/Driver/CMakeLists.txt
+++ b/lib/Driver/CMakeLists.txt
@@ -57,6 +57,7 @@ add_clang_library(clangDriver
   ToolChains/NetBSD.cpp
   ToolChains/OpenBSD.cpp
   ToolChains/PS4CPU.cpp
+  ToolChains/RISCV.cpp
   ToolChains/Solaris.cpp
   ToolChains/TCE.cpp
   ToolChains/WebAssembly.cpp
diff --git a/lib/Driver/Driver.cpp b/lib/Driver/Driver.cpp
index 1dfcacc75e..952a716cb6 100644
--- a/lib/Driver/Driver.cpp
+++ b/lib/Driver/Driver.cpp
@@ -37,6 +37,7 @@
 #include "ToolChains/NetBSD.h"
 #include "ToolChains/OpenBSD.h"
 #include "ToolChains/PS4CPU.h"
+#include "ToolChains/RISCV.h"
 #include "ToolChains/Solaris.h"
 #include "ToolChains/TCE.h"
 #include "ToolChains/WebAssembly.h"
@@ -4399,6 +4400,10 @@ const ToolChain &Driver::getToolChain(const ArgList &Args,
       case llvm::Triple::avr:
         TC = llvm::make_unique<toolchains::AVRToolChain>(*this, Target, Args);
         break;
+      case llvm::Triple::riscv32:
+      case llvm::Triple::riscv64:
+        TC = llvm::make_unique<toolchains::RISCVToolChain>(*this, Target, Args);
+        break;
       default:
         if (Target.getVendor() == llvm::Triple::Myriad)
           TC = llvm::make_unique<toolchains::MyriadToolChain>(*this, Target,
diff --git a/lib/Driver/ToolChains/Gnu.cpp b/lib/Driver/ToolChains/Gnu.cpp
index ad702b6d06..3755673250 100644
--- a/lib/Driver/ToolChains/Gnu.cpp
+++ b/lib/Driver/ToolChains/Gnu.cpp
@@ -1877,7 +1877,8 @@ void Generic_GCC::GCCInstallationDetector::AddDefaultGCCPrefixes(
 
   static const char *const RISCV32LibDirs[] = {"/lib", "/lib32"};
   static const char *const RISCVTriples[] = {"riscv32-unknown-linux-gnu",
-                                             "riscv64-unknown-linux-gnu"};
+                                             "riscv64-unknown-linux-gnu",
+                                             "riscv32-unknown-elf"};
 
   static const char *const SPARCv8LibDirs[] = {"/lib32", "/lib"};
   static const char *const SPARCv8Triples[] = {"sparc-linux-gnu",
diff --git a/lib/Driver/ToolChains/RISCV.cpp b/lib/Driver/ToolChains/RISCV.cpp
new file mode 100644
index 0000000000..31996fc588
--- /dev/null
+++ b/lib/Driver/ToolChains/RISCV.cpp
@@ -0,0 +1,117 @@
+//===--- RISCV.cpp - RISCV ToolChain Implementations ------------*- 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 "CommonArgs.h"
+#include "InputInfo.h"
+#include "clang/Driver/Compilation.h"
+#include "clang/Driver/Options.h"
+#include "llvm/Option/ArgList.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace clang::driver;
+using namespace clang::driver::toolchains;
+using namespace clang::driver::tools;
+using namespace clang;
+using namespace llvm::opt;
+
+/// RISCV Toolchain
+RISCVToolChain::RISCVToolChain(const Driver &D, const llvm::Triple &Triple,
+                               const ArgList &Args)
+    : Generic_ELF(D, Triple, Args) {
+  GCCInstallation.init(Triple, Args);
+  getFilePaths().push_back(D.SysRoot + "/lib");
+  if (GCCInstallation.isValid()) {
+    getFilePaths().push_back(GCCInstallation.getInstallPath().str());
+    getProgramPaths().push_back(
+        (GCCInstallation.getParentLibPath() + "/../bin").str());
+  }
+}
+
+Tool *RISCVToolChain::buildLinker() const {
+  return new tools::RISCV::Linker(*this);
+}
+
+void RISCVToolChain::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
+                                               ArgStringList &CC1Args) const {
+  if (DriverArgs.hasArg(options::OPT_nostdinc))
+    return;
+
+  if (!DriverArgs.hasArg(options::OPT_nostdlibinc)) {
+    SmallString<128> Dir(getDriver().SysRoot);
+    llvm::sys::path::append(Dir, "include");
+    addSystemInclude(DriverArgs, CC1Args, Dir.str());
+  }
+}
+
+void RISCVToolChain::addLibStdCxxIncludePaths(
+    const llvm::opt::ArgList &DriverArgs,
+    llvm::opt::ArgStringList &CC1Args) const {
+  StringRef LibDir = GCCInstallation.getParentLibPath();
+  const GCCVersion &Version = GCCInstallation.getVersion();
+  StringRef TripleStr = GCCInstallation.getTriple().str();
+  const Multilib &Multilib = GCCInstallation.getMultilib();
+  addLibStdCXXIncludePaths(
+      LibDir.str() + "/../" + TripleStr.str() + "/include/c++/" + Version.Text,
+      "", TripleStr, "", "", Multilib.includeSuffix(), DriverArgs, CC1Args);
+}
+
+void RISCV::Linker::ConstructJob(Compilation &C, const JobAction &JA,
+                                 const InputInfo &Output,
+                                 const InputInfoList &Inputs,
+                                 const ArgList &Args,
+                                 const char *LinkingOutput) const {
+  const ToolChain &ToolChain = getToolChain();
+  const Driver &D = ToolChain.getDriver();
+  ArgStringList CmdArgs;
+
+  if (!D.SysRoot.empty())
+    CmdArgs.push_back(Args.MakeArgString("--sysroot=" + D.SysRoot));
+
+  std::string Linker = getToolChain().GetProgramPath(getShortName());
+
+  bool WantCRTs =
+      !Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles);
+
+  if (WantCRTs) {
+    CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crt0.o")));
+    CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crtbegin.o")));
+  }
+
+  Args.AddAllArgs(CmdArgs, options::OPT_L);
+  ToolChain.AddFilePathLibArgs(Args, CmdArgs);
+  Args.AddAllArgs(CmdArgs,
+                  {options::OPT_T_Group, options::OPT_e, options::OPT_s,
+                   options::OPT_t, options::OPT_Z_Flag, options::OPT_r});
+
+  AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
+
+  // TODO: add C++ includes and libs if compiling C++.
+
+  if (!Args.hasArg(options::OPT_nostdlib) &&
+      !Args.hasArg(options::OPT_nodefaultlibs)) {
+    if (ToolChain.ShouldLinkCXXStdlib(Args))
+      ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
+    CmdArgs.push_back("--start-group");
+    CmdArgs.push_back("-lc");
+    CmdArgs.push_back("-lgloss");
+    CmdArgs.push_back("--end-group");
+    CmdArgs.push_back("-lgcc");
+  }
+
+  if (WantCRTs)
+    CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crtend.o")));
+
+  CmdArgs.push_back("-o");
+  CmdArgs.push_back(Output.getFilename());
+  C.addCommand(llvm::make_unique<Command>(JA, *this, Args.MakeArgString(Linker),
+                                          CmdArgs, Inputs));
+}
+// RISCV tools end.
diff --git a/lib/Driver/ToolChains/RISCV.h b/lib/Driver/ToolChains/RISCV.h
new file mode 100644
index 0000000000..6f59d84020
--- /dev/null
+++ b/lib/Driver/ToolChains/RISCV.h
@@ -0,0 +1,57 @@
+//===--- RISCV.h - RISCV ToolChain Implementations --------------*- 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_RISCV_H
+#define LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_RISCV_H
+
+#include "Gnu.h"
+#include "clang/Driver/ToolChain.h"
+
+namespace clang {
+namespace driver {
+namespace toolchains {
+
+class LLVM_LIBRARY_VISIBILITY RISCVToolChain : public Generic_ELF {
+public:
+  RISCVToolChain(const Driver &D, const llvm::Triple &Triple,
+                 const llvm::opt::ArgList &Args);
+
+  bool IsIntegratedAssemblerDefault() const override { return true; }
+  void
+  AddClangSystemIncludeArgs(const llvm::opt::ArgList &DriverArgs,
+                            llvm::opt::ArgStringList &CC1Args) const override;
+  void
+  addLibStdCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
+                           llvm::opt::ArgStringList &CC1Args) const override;
+
+protected:
+  Tool *buildLinker() const override;
+};
+
+} // end namespace toolchains
+
+namespace tools {
+namespace RISCV {
+class LLVM_LIBRARY_VISIBILITY Linker : public GnuTool {
+public:
+  Linker(const ToolChain &TC) : GnuTool("RISCV::Linker", "ld", TC) {}
+  bool hasIntegratedCPP() const override { return false; }
+  bool isLinkJob() const override { return true; }
+  void ConstructJob(Compilation &C, const JobAction &JA,
+                    const InputInfo &Output, const InputInfoList &Inputs,
+                    const llvm::opt::ArgList &TCArgs,
+                    const char *LinkingOutput) const override;
+};
+} // end namespace RISCV
+} // end namespace tools
+
+} // end namespace driver
+} // end namespace clang
+
+#endif // LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_RISCV_H
diff --git a/test/Driver/Inputs/basic_riscv32_tree/bin/riscv32-unknown-elf-ld b/test/Driver/Inputs/basic_riscv32_tree/bin/riscv32-unknown-elf-ld
new file mode 100755
index 0000000000..b23e55619b
--- /dev/null
+++ b/test/Driver/Inputs/basic_riscv32_tree/bin/riscv32-unknown-elf-ld
@@ -0,0 +1 @@
+#!/bin/true
diff --git a/test/Driver/Inputs/basic_riscv32_tree/lib/gcc/riscv32-unknown-elf/8.0.1/crtbegin.o b/test/Driver/Inputs/basic_riscv32_tree/lib/gcc/riscv32-unknown-elf/8.0.1/crtbegin.o
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/test/Driver/Inputs/basic_riscv32_tree/lib/gcc/riscv32-unknown-elf/8.0.1/crtbegin.o
diff --git a/test/Driver/Inputs/basic_riscv32_tree/lib/gcc/riscv32-unknown-elf/8.0.1/crtend.o b/test/Driver/Inputs/basic_riscv32_tree/lib/gcc/riscv32-unknown-elf/8.0.1/crtend.o
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/test/Driver/Inputs/basic_riscv32_tree/lib/gcc/riscv32-unknown-elf/8.0.1/crtend.o
diff --git a/test/Driver/Inputs/basic_riscv32_tree/riscv32-unknown-elf/include/c++/8.0.1/.keep b/test/Driver/Inputs/basic_riscv32_tree/riscv32-unknown-elf/include/c++/8.0.1/.keep
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/test/Driver/Inputs/basic_riscv32_tree/riscv32-unknown-elf/include/c++/8.0.1/.keep
diff --git a/test/Driver/Inputs/basic_riscv32_tree/riscv32-unknown-elf/lib/crt0.o b/test/Driver/Inputs/basic_riscv32_tree/riscv32-unknown-elf/lib/crt0.o
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/test/Driver/Inputs/basic_riscv32_tree/riscv32-unknown-elf/lib/crt0.o
diff --git a/test/Driver/riscv32-toolchain.c b/test/Driver/riscv32-toolchain.c
index 1e93e97c53..77d945b046 100644
--- a/test/Driver/riscv32-toolchain.c
+++ b/test/Driver/riscv32-toolchain.c
@@ -3,6 +3,36 @@
 // RUN: %clang %s -### -no-canonical-prefixes -target riscv32 2>&1 | FileCheck -check-prefix=CC1 %s
 // CC1: clang{{.*}} "-cc1" "-triple" "riscv32"
 
+// RUN: %clang %s -### -no-canonical-prefixes \
+// RUN:   -target riscv32-unknown-elf \
+// RUN:   --gcc-toolchain=%S/Inputs/basic_riscv32_tree \
+// RUN:   --sysroot=%S/Inputs/basic_riscv32_tree/riscv32-unknown-elf 2>&1 \
+// RUN:   | FileCheck -check-prefix=C-RV32-BAREMETAL-ILP32 %s
+
+// C-RV32-BAREMETAL-ILP32: "{{.*}}Inputs/basic_riscv32_tree/lib/gcc/riscv32-unknown-elf/8.0.1/../../../../bin{{/|\\\\}}riscv32-unknown-elf-ld"
+// C-RV32-BAREMETAL-ILP32: "--sysroot={{.*}}/Inputs/basic_riscv32_tree/riscv32-unknown-elf"
+// C-RV32-BAREMETAL-ILP32: "{{.*}}/Inputs/basic_riscv32_tree/riscv32-unknown-elf/lib{{/|\\\\}}crt0.o"
+// C-RV32-BAREMETAL-ILP32: "{{.*}}/Inputs/basic_riscv32_tree/lib/gcc/riscv32-unknown-elf/8.0.1{{/|\\\\}}crtbegin.o"
+// C-RV32-BAREMETAL-ILP32: "-L{{.*}}/Inputs/basic_riscv32_tree/riscv32-unknown-elf/lib"
+// C-RV32-BAREMETAL-ILP32: "-L{{.*}}/Inputs/basic_riscv32_tree/lib/gcc/riscv32-unknown-elf/8.0.1"
+// C-RV32-BAREMETAL-ILP32: "--start-group" "-lc" "-lgloss" "--end-group" "-lgcc"
+// C-RV32-BAREMETAL-ILP32: "{{.*}}/Inputs/basic_riscv32_tree/lib/gcc/riscv32-unknown-elf/8.0.1{{/|\\\\}}crtend.o"
+
+// RUN: %clangxx %s -### -no-canonical-prefixes \
+// RUN:   -target riscv32-unknown-elf \
+// RUN:   --gcc-toolchain=%S/Inputs/basic_riscv32_tree \
+// RUN:   --sysroot=%S/Inputs/basic_riscv32_tree/riscv32-unknown-elf 2>&1 \
+// RUN:   | FileCheck -check-prefix=CXX-RV32-BAREMETAL-ILP32 %s
+
+// CXX-RV32-BAREMETAL-ILP32: "-internal-isystem" "{{.*}}Inputs/basic_riscv32_tree/lib/gcc/riscv32-unknown-elf/8.0.1/../../../../riscv32-unknown-elf/include/c++{{/|\\\\}}8.0.1"
+// CXX-RV32-BAREMETAL-ILP32: "{{.*}}Inputs/basic_riscv32_tree/lib/gcc/riscv32-unknown-elf/8.0.1/../../../../bin{{/|\\\\}}riscv32-unknown-elf-ld"
+// CXX-RV32-BAREMETAL-ILP32: "--sysroot={{.*}}/Inputs/basic_riscv32_tree/riscv32-unknown-elf"
+// CXX-RV32-BAREMETAL-ILP32: "{{.*}}/Inputs/basic_riscv32_tree/riscv32-unknown-elf/lib{{/|\\\\}}crt0.o"
+// CXX-RV32-BAREMETAL-ILP32: "{{.*}}/Inputs/basic_riscv32_tree/lib/gcc/riscv32-unknown-elf/8.0.1{{/|\\\\}}crtbegin.o"
+// CXX-RV32-BAREMETAL-ILP32: "-L{{.*}}/Inputs/basic_riscv32_tree/riscv32-unknown-elf/lib"
+// CXX-RV32-BAREMETAL-ILP32: "-L{{.*}}/Inputs/basic_riscv32_tree/lib/gcc/riscv32-unknown-elf/8.0.1"
+// CXX-RV32-BAREMETAL-ILP32: "-lstdc++" "--start-group" "-lc" "-lgloss" "--end-group" "-lgcc"
+// CXX-RV32-BAREMETAL-ILP32: "{{.*}}/Inputs/basic_riscv32_tree/lib/gcc/riscv32-unknown-elf/8.0.1{{/|\\\\}}crtend.o"
 
 // RUN: %clang %s -### -no-canonical-prefixes -fuse-ld=ld \
 // RUN:   -target riscv32-linux-unknown-elf \