1 files changed, 159 insertions, 0 deletions
diff --git a/clang/lib/Driver/ToolChains/AVR.cpp b/clang/lib/Driver/ToolChains/AVR.cpp
new file mode 100644
index 000000000000..e8a3a7b38c31
--- /dev/null
+++ b/clang/lib/Driver/ToolChains/AVR.cpp
@@ -0,0 +1,159 @@
+//===--- AVR.cpp - AVR 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 "AVR.h"
+#include "CommonArgs.h"
+#include "InputInfo.h"
+#include "clang/Driver/Compilation.h"
+#include "clang/Driver/DriverDiagnostic.h"
+#include "clang/Driver/Options.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/MC/SubtargetFeature.h"
+#include "llvm/Option/ArgList.h"
+#include "llvm/Support/FileSystem.h"
+
+using namespace clang::driver;
+using namespace clang::driver::toolchains;
+using namespace clang::driver::tools;
+using namespace clang;
+using namespace llvm::opt;
+
+namespace {
+
+// TODO: Consider merging this into the AVR device table
+// array in Targets/AVR.cpp.
+llvm::Optional<StringRef> GetMcuFamilyName(StringRef MCU) {
+  return llvm::StringSwitch<llvm::Optional<StringRef>>(MCU)
+      .Case("atmega328", Optional<StringRef>("avr5"))
+      .Case("atmega328p", Optional<StringRef>("avr5"))
+      .Default(Optional<StringRef>());
+}
+
+const StringRef PossibleAVRLibcLocations[] = {
+    "/usr/avr",
+    "/usr/lib/avr",
+};
+
+} // end anonymous namespace
+
+/// AVR Toolchain
+AVRToolChain::AVRToolChain(const Driver &D, const llvm::Triple &Triple,
+                           const ArgList &Args)
+    : Generic_ELF(D, Triple, Args), LinkStdlib(false) {
+  GCCInstallation.init(Triple, Args);
+
+  // Only add default libraries if the user hasn't explicitly opted out.
+  if (!Args.hasArg(options::OPT_nostdlib) &&
+      !Args.hasArg(options::OPT_nodefaultlibs) &&
+      !Args.hasArg(options::OPT_c /* does not apply when not linking */)) {
+    std::string CPU = getCPUName(Args, Triple);
+
+    if (CPU.empty()) {
+      // We cannot link any standard libraries without an MCU specified.
+      D.Diag(diag::warn_drv_avr_mcu_not_specified);
+    } else {
+      Optional<StringRef> FamilyName = GetMcuFamilyName(CPU);
+      Optional<std::string> AVRLibcRoot = findAVRLibcInstallation();
+
+      if (!FamilyName.hasValue()) {
+        // We do not have an entry for this CPU in the family
+        // mapping table yet.
+        D.Diag(diag::warn_drv_avr_family_linking_stdlibs_not_implemented)
+            << CPU;
+      } else if (!GCCInstallation.isValid()) {
+        // No avr-gcc found and so no runtime linked.
+        D.Diag(diag::warn_drv_avr_gcc_not_found);
+      } else if (!AVRLibcRoot.hasValue()) {
+        // No avr-libc found and so no runtime linked.
+        D.Diag(diag::warn_drv_avr_libc_not_found);
+      } else { // We have enough information to link stdlibs
+        std::string GCCRoot = GCCInstallation.getInstallPath();
+        std::string LibcRoot = AVRLibcRoot.getValue();
+
+        getFilePaths().push_back(LibcRoot + std::string("/lib/") +
+                                 std::string(*FamilyName));
+        getFilePaths().push_back(LibcRoot + std::string("/lib/") +
+                                 std::string(*FamilyName));
+        getFilePaths().push_back(GCCRoot + std::string("/") +
+                                 std::string(*FamilyName));
+
+        LinkStdlib = true;
+      }
+    }
+
+    if (!LinkStdlib)
+      D.Diag(diag::warn_drv_avr_stdlib_not_linked);
+  }
+}
+
+Tool *AVRToolChain::buildLinker() const {
+  return new tools::AVR::Linker(getTriple(), *this, LinkStdlib);
+}
+
+void AVR::Linker::ConstructJob(Compilation &C, const JobAction &JA,
+                               const InputInfo &Output,
+                               const InputInfoList &Inputs,
+                               const ArgList &Args,
+                               const char *LinkingOutput) const {
+  // Compute information about the target AVR.
+  std::string CPU = getCPUName(Args, getToolChain().getTriple());
+  llvm::Optional<StringRef> FamilyName = GetMcuFamilyName(CPU);
+
+  std::string Linker = getToolChain().GetProgramPath(getShortName());
+  ArgStringList CmdArgs;
+  AddLinkerInputs(getToolChain(), Inputs, Args, CmdArgs, JA);
+
+  CmdArgs.push_back("-o");
+  CmdArgs.push_back(Output.getFilename());
+
+  // Enable garbage collection of unused sections.
+  CmdArgs.push_back("--gc-sections");
+
+  // Add library search paths before we specify libraries.
+  Args.AddAllArgs(CmdArgs, options::OPT_L);
+  getToolChain().AddFilePathLibArgs(Args, CmdArgs);
+
+  // If the family name is known, we can link with the device-specific libgcc.
+  // Without it, libgcc will simply not be linked. This matches avr-gcc
+  // behavior.
+  if (LinkStdlib) {
+    assert(!CPU.empty() && "CPU name must be known in order to link stdlibs");
+
+    // Add the object file for the CRT.
+    std::string CrtFileName = std::string("-l:crt") + CPU + std::string(".o");
+    CmdArgs.push_back(Args.MakeArgString(CrtFileName));
+
+    CmdArgs.push_back("-lgcc");
+    CmdArgs.push_back("-lm");
+    CmdArgs.push_back("-lc");
+
+    // Add the link library specific to the MCU.
+    CmdArgs.push_back(Args.MakeArgString(std::string("-l") + CPU));
+
+    // Specify the family name as the emulation mode to use.
+    // This is almost always required because otherwise avr-ld
+    // will assume 'avr2' and warn about the program being larger
+    // than the bare minimum supports.
+    CmdArgs.push_back(Args.MakeArgString(std::string("-m") + *FamilyName));
+  }
+
+  C.addCommand(std::make_unique<Command>(JA, *this, Args.MakeArgString(Linker),
+                                          CmdArgs, Inputs));
+}
+
+llvm::Optional<std::string> AVRToolChain::findAVRLibcInstallation() const {
+  for (StringRef PossiblePath : PossibleAVRLibcLocations) {
+    // Return the first avr-libc installation that exists.
+    if (llvm::sys::fs::is_directory(PossiblePath))
+      return Optional<std::string>(std::string(PossiblePath));
+  }
+
+  return llvm::None;
+}