Cuda.cpp revision 360784 
1//===--- Cuda.cpp - Cuda Tool and ToolChain Implementations -----*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "Cuda.h"
10#include "CommonArgs.h"
11#include "InputInfo.h"
12#include "clang/Basic/Cuda.h"
13#include "clang/Config/config.h"
14#include "clang/Driver/Compilation.h"
15#include "clang/Driver/Distro.h"
16#include "clang/Driver/Driver.h"
17#include "clang/Driver/DriverDiagnostic.h"
18#include "clang/Driver/Options.h"
19#include "llvm/Option/ArgList.h"
20#include "llvm/Support/FileSystem.h"
21#include "llvm/Support/Path.h"
22#include "llvm/Support/Process.h"
23#include "llvm/Support/Program.h"
24#include "llvm/Support/VirtualFileSystem.h"
25#include <system_error>
26
27using namespace clang::driver;
28using namespace clang::driver::toolchains;
29using namespace clang::driver::tools;
30using namespace clang;
31using namespace llvm::opt;
32
33// Parses the contents of version.txt in an CUDA installation.  It should
34// contain one line of the from e.g. "CUDA Version 7.5.2".
35void CudaInstallationDetector::ParseCudaVersionFile(llvm::StringRef V) {
36  Version = CudaVersion::UNKNOWN;
37  if (!V.startswith("CUDA Version "))
38    return;
39  V = V.substr(strlen("CUDA Version "));
40  SmallVector<StringRef,4> VersionParts;
41  V.split(VersionParts, '.');
42  if (VersionParts.size() < 2)
43    return;
44  DetectedVersion = join_items(".", VersionParts[0], VersionParts[1]);
45  Version = CudaStringToVersion(DetectedVersion);
46  if (Version != CudaVersion::UNKNOWN)
47    return;
48
49  Version = CudaVersion::LATEST;
50  DetectedVersionIsNotSupported = true;
51}
52
53void CudaInstallationDetector::WarnIfUnsupportedVersion() {
54  if (DetectedVersionIsNotSupported)
55    D.Diag(diag::warn_drv_unknown_cuda_version)
56        << DetectedVersion << CudaVersionToString(Version);
57}
58
59CudaInstallationDetector::CudaInstallationDetector(
60    const Driver &D, const llvm::Triple &HostTriple,
61    const llvm::opt::ArgList &Args)
62    : D(D) {
63  struct Candidate {
64    std::string Path;
65    bool StrictChecking;
66
67    Candidate(std::string Path, bool StrictChecking = false)
68        : Path(Path), StrictChecking(StrictChecking) {}
69  };
70  SmallVector<Candidate, 4> Candidates;
71
72  // In decreasing order so we prefer newer versions to older versions.
73  std::initializer_list<const char *> Versions = {"8.0", "7.5", "7.0"};
74
75  if (Args.hasArg(clang::driver::options::OPT_cuda_path_EQ)) {
76    Candidates.emplace_back(
77        Args.getLastArgValue(clang::driver::options::OPT_cuda_path_EQ).str());
78  } else if (HostTriple.isOSWindows()) {
79    for (const char *Ver : Versions)
80      Candidates.emplace_back(
81          D.SysRoot + "/Program Files/NVIDIA GPU Computing Toolkit/CUDA/v" +
82          Ver);
83  } else {
84    if (!Args.hasArg(clang::driver::options::OPT_cuda_path_ignore_env)) {
85      // Try to find ptxas binary. If the executable is located in a directory
86      // called 'bin/', its parent directory might be a good guess for a valid
87      // CUDA installation.
88      // However, some distributions might installs 'ptxas' to /usr/bin. In that
89      // case the candidate would be '/usr' which passes the following checks
90      // because '/usr/include' exists as well. To avoid this case, we always
91      // check for the directory potentially containing files for libdevice,
92      // even if the user passes -nocudalib.
93      if (llvm::ErrorOr<std::string> ptxas =
94              llvm::sys::findProgramByName("ptxas")) {
95        SmallString<256> ptxasAbsolutePath;
96        llvm::sys::fs::real_path(*ptxas, ptxasAbsolutePath);
97
98        StringRef ptxasDir = llvm::sys::path::parent_path(ptxasAbsolutePath);
99        if (llvm::sys::path::filename(ptxasDir) == "bin")
100          Candidates.emplace_back(llvm::sys::path::parent_path(ptxasDir),
101                                  /*StrictChecking=*/true);
102      }
103    }
104
105    Candidates.emplace_back(D.SysRoot + "/usr/local/cuda");
106    for (const char *Ver : Versions)
107      Candidates.emplace_back(D.SysRoot + "/usr/local/cuda-" + Ver);
108
109    Distro Dist(D.getVFS(), llvm::Triple(llvm::sys::getProcessTriple()));
110    if (Dist.IsDebian() || Dist.IsUbuntu())
111      // Special case for Debian to have nvidia-cuda-toolkit work
112      // out of the box. More info on http://bugs.debian.org/882505
113      Candidates.emplace_back(D.SysRoot + "/usr/lib/cuda");
114  }
115
116  bool NoCudaLib = Args.hasArg(options::OPT_nogpulib);
117
118  for (const auto &Candidate : Candidates) {
119    InstallPath = Candidate.Path;
120    if (InstallPath.empty() || !D.getVFS().exists(InstallPath))
121      continue;
122
123    BinPath = InstallPath + "/bin";
124    IncludePath = InstallPath + "/include";
125    LibDevicePath = InstallPath + "/nvvm/libdevice";
126
127    auto &FS = D.getVFS();
128    if (!(FS.exists(IncludePath) && FS.exists(BinPath)))
129      continue;
130    bool CheckLibDevice = (!NoCudaLib || Candidate.StrictChecking);
131    if (CheckLibDevice && !FS.exists(LibDevicePath))
132      continue;
133
134    // On Linux, we have both lib and lib64 directories, and we need to choose
135    // based on our triple.  On MacOS, we have only a lib directory.
136    //
137    // It's sufficient for our purposes to be flexible: If both lib and lib64
138    // exist, we choose whichever one matches our triple.  Otherwise, if only
139    // lib exists, we use it.
140    if (HostTriple.isArch64Bit() && FS.exists(InstallPath + "/lib64"))
141      LibPath = InstallPath + "/lib64";
142    else if (FS.exists(InstallPath + "/lib"))
143      LibPath = InstallPath + "/lib";
144    else
145      continue;
146
147    llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> VersionFile =
148        FS.getBufferForFile(InstallPath + "/version.txt");
149    if (!VersionFile) {
150      // CUDA 7.0 doesn't have a version.txt, so guess that's our version if
151      // version.txt isn't present.
152      Version = CudaVersion::CUDA_70;
153    } else {
154      ParseCudaVersionFile((*VersionFile)->getBuffer());
155    }
156
157    if (Version >= CudaVersion::CUDA_90) {
158      // CUDA-9+ uses single libdevice file for all GPU variants.
159      std::string FilePath = LibDevicePath + "/libdevice.10.bc";
160      if (FS.exists(FilePath)) {
161        for (const char *GpuArchName :
162             {"sm_30", "sm_32", "sm_35", "sm_37", "sm_50", "sm_52", "sm_53",
163              "sm_60", "sm_61", "sm_62", "sm_70", "sm_72", "sm_75"}) {
164          const CudaArch GpuArch = StringToCudaArch(GpuArchName);
165          if (Version >= MinVersionForCudaArch(GpuArch) &&
166              Version <= MaxVersionForCudaArch(GpuArch))
167            LibDeviceMap[GpuArchName] = FilePath;
168        }
169      }
170    } else {
171      std::error_code EC;
172      for (llvm::sys::fs::directory_iterator LI(LibDevicePath, EC), LE;
173           !EC && LI != LE; LI = LI.increment(EC)) {
174        StringRef FilePath = LI->path();
175        StringRef FileName = llvm::sys::path::filename(FilePath);
176        // Process all bitcode filenames that look like
177        // libdevice.compute_XX.YY.bc
178        const StringRef LibDeviceName = "libdevice.";
179        if (!(FileName.startswith(LibDeviceName) && FileName.endswith(".bc")))
180          continue;
181        StringRef GpuArch = FileName.slice(
182            LibDeviceName.size(), FileName.find('.', LibDeviceName.size()));
183        LibDeviceMap[GpuArch] = FilePath.str();
184        // Insert map entries for specific devices with this compute
185        // capability. NVCC's choice of the libdevice library version is
186        // rather peculiar and depends on the CUDA version.
187        if (GpuArch == "compute_20") {
188          LibDeviceMap["sm_20"] = FilePath;
189          LibDeviceMap["sm_21"] = FilePath;
190          LibDeviceMap["sm_32"] = FilePath;
191        } else if (GpuArch == "compute_30") {
192          LibDeviceMap["sm_30"] = FilePath;
193          if (Version < CudaVersion::CUDA_80) {
194            LibDeviceMap["sm_50"] = FilePath;
195            LibDeviceMap["sm_52"] = FilePath;
196            LibDeviceMap["sm_53"] = FilePath;
197          }
198          LibDeviceMap["sm_60"] = FilePath;
199          LibDeviceMap["sm_61"] = FilePath;
200          LibDeviceMap["sm_62"] = FilePath;
201        } else if (GpuArch == "compute_35") {
202          LibDeviceMap["sm_35"] = FilePath;
203          LibDeviceMap["sm_37"] = FilePath;
204        } else if (GpuArch == "compute_50") {
205          if (Version >= CudaVersion::CUDA_80) {
206            LibDeviceMap["sm_50"] = FilePath;
207            LibDeviceMap["sm_52"] = FilePath;
208            LibDeviceMap["sm_53"] = FilePath;
209          }
210        }
211      }
212    }
213
214    // Check that we have found at least one libdevice that we can link in if
215    // -nocudalib hasn't been specified.
216    if (LibDeviceMap.empty() && !NoCudaLib)
217      continue;
218
219    IsValid = true;
220    break;
221  }
222}
223
224void CudaInstallationDetector::AddCudaIncludeArgs(
225    const ArgList &DriverArgs, ArgStringList &CC1Args) const {
226  if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
227    // Add cuda_wrappers/* to our system include path.  This lets us wrap
228    // standard library headers.
229    SmallString<128> P(D.ResourceDir);
230    llvm::sys::path::append(P, "include");
231    llvm::sys::path::append(P, "cuda_wrappers");
232    CC1Args.push_back("-internal-isystem");
233    CC1Args.push_back(DriverArgs.MakeArgString(P));
234  }
235
236  if (DriverArgs.hasArg(options::OPT_nocudainc))
237    return;
238
239  if (!isValid()) {
240    D.Diag(diag::err_drv_no_cuda_installation);
241    return;
242  }
243
244  CC1Args.push_back("-internal-isystem");
245  CC1Args.push_back(DriverArgs.MakeArgString(getIncludePath()));
246  CC1Args.push_back("-include");
247  CC1Args.push_back("__clang_cuda_runtime_wrapper.h");
248}
249
250void CudaInstallationDetector::CheckCudaVersionSupportsArch(
251    CudaArch Arch) const {
252  if (Arch == CudaArch::UNKNOWN || Version == CudaVersion::UNKNOWN ||
253      ArchsWithBadVersion.count(Arch) > 0)
254    return;
255
256  auto MinVersion = MinVersionForCudaArch(Arch);
257  auto MaxVersion = MaxVersionForCudaArch(Arch);
258  if (Version < MinVersion || Version > MaxVersion) {
259    ArchsWithBadVersion.insert(Arch);
260    D.Diag(diag::err_drv_cuda_version_unsupported)
261        << CudaArchToString(Arch) << CudaVersionToString(MinVersion)
262        << CudaVersionToString(MaxVersion) << InstallPath
263        << CudaVersionToString(Version);
264  }
265}
266
267void CudaInstallationDetector::print(raw_ostream &OS) const {
268  if (isValid())
269    OS << "Found CUDA installation: " << InstallPath << ", version "
270       << CudaVersionToString(Version) << "\n";
271}
272
273namespace {
274/// Debug info level for the NVPTX devices. We may need to emit different debug
275/// info level for the host and for the device itselfi. This type controls
276/// emission of the debug info for the devices. It either prohibits disable info
277/// emission completely, or emits debug directives only, or emits same debug
278/// info as for the host.
279enum DeviceDebugInfoLevel {
280  DisableDebugInfo,        /// Do not emit debug info for the devices.
281  DebugDirectivesOnly,     /// Emit only debug directives.
282  EmitSameDebugInfoAsHost, /// Use the same debug info level just like for the
283                           /// host.
284};
285} // anonymous namespace
286
287/// Define debug info level for the NVPTX devices. If the debug info for both
288/// the host and device are disabled (-g0/-ggdb0 or no debug options at all). If
289/// only debug directives are requested for the both host and device
290/// (-gline-directvies-only), or the debug info only for the device is disabled
291/// (optimization is on and --cuda-noopt-device-debug was not specified), the
292/// debug directves only must be emitted for the device. Otherwise, use the same
293/// debug info level just like for the host (with the limitations of only
294/// supported DWARF2 standard).
295static DeviceDebugInfoLevel mustEmitDebugInfo(const ArgList &Args) {
296  const Arg *A = Args.getLastArg(options::OPT_O_Group);
297  bool IsDebugEnabled = !A || A->getOption().matches(options::OPT_O0) ||
298                        Args.hasFlag(options::OPT_cuda_noopt_device_debug,
299                                     options::OPT_no_cuda_noopt_device_debug,
300                                     /*Default=*/false);
301  if (const Arg *A = Args.getLastArg(options::OPT_g_Group)) {
302    const Option &Opt = A->getOption();
303    if (Opt.matches(options::OPT_gN_Group)) {
304      if (Opt.matches(options::OPT_g0) || Opt.matches(options::OPT_ggdb0))
305        return DisableDebugInfo;
306      if (Opt.matches(options::OPT_gline_directives_only))
307        return DebugDirectivesOnly;
308    }
309    return IsDebugEnabled ? EmitSameDebugInfoAsHost : DebugDirectivesOnly;
310  }
311  return DisableDebugInfo;
312}
313
314void NVPTX::Assembler::ConstructJob(Compilation &C, const JobAction &JA,
315                                    const InputInfo &Output,
316                                    const InputInfoList &Inputs,
317                                    const ArgList &Args,
318                                    const char *LinkingOutput) const {
319  const auto &TC =
320      static_cast<const toolchains::CudaToolChain &>(getToolChain());
321  assert(TC.getTriple().isNVPTX() && "Wrong platform");
322
323  StringRef GPUArchName;
324  // If this is an OpenMP action we need to extract the device architecture
325  // from the -march=arch option. This option may come from -Xopenmp-target
326  // flag or the default value.
327  if (JA.isDeviceOffloading(Action::OFK_OpenMP)) {
328    GPUArchName = Args.getLastArgValue(options::OPT_march_EQ);
329    assert(!GPUArchName.empty() && "Must have an architecture passed in.");
330  } else
331    GPUArchName = JA.getOffloadingArch();
332
333  // Obtain architecture from the action.
334  CudaArch gpu_arch = StringToCudaArch(GPUArchName);
335  assert(gpu_arch != CudaArch::UNKNOWN &&
336         "Device action expected to have an architecture.");
337
338  // Check that our installation's ptxas supports gpu_arch.
339  if (!Args.hasArg(options::OPT_no_cuda_version_check)) {
340    TC.CudaInstallation.CheckCudaVersionSupportsArch(gpu_arch);
341  }
342
343  ArgStringList CmdArgs;
344  CmdArgs.push_back(TC.getTriple().isArch64Bit() ? "-m64" : "-m32");
345  DeviceDebugInfoLevel DIKind = mustEmitDebugInfo(Args);
346  if (DIKind == EmitSameDebugInfoAsHost) {
347    // ptxas does not accept -g option if optimization is enabled, so
348    // we ignore the compiler's -O* options if we want debug info.
349    CmdArgs.push_back("-g");
350    CmdArgs.push_back("--dont-merge-basicblocks");
351    CmdArgs.push_back("--return-at-end");
352  } else if (Arg *A = Args.getLastArg(options::OPT_O_Group)) {
353    // Map the -O we received to -O{0,1,2,3}.
354    //
355    // TODO: Perhaps we should map host -O2 to ptxas -O3. -O3 is ptxas's
356    // default, so it may correspond more closely to the spirit of clang -O2.
357
358    // -O3 seems like the least-bad option when -Osomething is specified to
359    // clang but it isn't handled below.
360    StringRef OOpt = "3";
361    if (A->getOption().matches(options::OPT_O4) ||
362        A->getOption().matches(options::OPT_Ofast))
363      OOpt = "3";
364    else if (A->getOption().matches(options::OPT_O0))
365      OOpt = "0";
366    else if (A->getOption().matches(options::OPT_O)) {
367      // -Os, -Oz, and -O(anything else) map to -O2, for lack of better options.
368      OOpt = llvm::StringSwitch<const char *>(A->getValue())
369                 .Case("1", "1")
370                 .Case("2", "2")
371                 .Case("3", "3")
372                 .Case("s", "2")
373                 .Case("z", "2")
374                 .Default("2");
375    }
376    CmdArgs.push_back(Args.MakeArgString(llvm::Twine("-O") + OOpt));
377  } else {
378    // If no -O was passed, pass -O0 to ptxas -- no opt flag should correspond
379    // to no optimizations, but ptxas's default is -O3.
380    CmdArgs.push_back("-O0");
381  }
382  if (DIKind == DebugDirectivesOnly)
383    CmdArgs.push_back("-lineinfo");
384
385  // Pass -v to ptxas if it was passed to the driver.
386  if (Args.hasArg(options::OPT_v))
387    CmdArgs.push_back("-v");
388
389  CmdArgs.push_back("--gpu-name");
390  CmdArgs.push_back(Args.MakeArgString(CudaArchToString(gpu_arch)));
391  CmdArgs.push_back("--output-file");
392  CmdArgs.push_back(Args.MakeArgString(TC.getInputFilename(Output)));
393  for (const auto& II : Inputs)
394    CmdArgs.push_back(Args.MakeArgString(II.getFilename()));
395
396  for (const auto& A : Args.getAllArgValues(options::OPT_Xcuda_ptxas))
397    CmdArgs.push_back(Args.MakeArgString(A));
398
399  bool Relocatable = false;
400  if (JA.isOffloading(Action::OFK_OpenMP))
401    // In OpenMP we need to generate relocatable code.
402    Relocatable = Args.hasFlag(options::OPT_fopenmp_relocatable_target,
403                               options::OPT_fnoopenmp_relocatable_target,
404                               /*Default=*/true);
405  else if (JA.isOffloading(Action::OFK_Cuda))
406    Relocatable = Args.hasFlag(options::OPT_fgpu_rdc,
407                               options::OPT_fno_gpu_rdc, /*Default=*/false);
408
409  if (Relocatable)
410    CmdArgs.push_back("-c");
411
412  const char *Exec;
413  if (Arg *A = Args.getLastArg(options::OPT_ptxas_path_EQ))
414    Exec = A->getValue();
415  else
416    Exec = Args.MakeArgString(TC.GetProgramPath("ptxas"));
417  C.addCommand(std::make_unique<Command>(JA, *this, Exec, CmdArgs, Inputs));
418}
419
420static bool shouldIncludePTX(const ArgList &Args, const char *gpu_arch) {
421  bool includePTX = true;
422  for (Arg *A : Args) {
423    if (!(A->getOption().matches(options::OPT_cuda_include_ptx_EQ) ||
424          A->getOption().matches(options::OPT_no_cuda_include_ptx_EQ)))
425      continue;
426    A->claim();
427    const StringRef ArchStr = A->getValue();
428    if (ArchStr == "all" || ArchStr == gpu_arch) {
429      includePTX = A->getOption().matches(options::OPT_cuda_include_ptx_EQ);
430      continue;
431    }
432  }
433  return includePTX;
434}
435
436// All inputs to this linker must be from CudaDeviceActions, as we need to look
437// at the Inputs' Actions in order to figure out which GPU architecture they
438// correspond to.
439void NVPTX::Linker::ConstructJob(Compilation &C, const JobAction &JA,
440                                 const InputInfo &Output,
441                                 const InputInfoList &Inputs,
442                                 const ArgList &Args,
443                                 const char *LinkingOutput) const {
444  const auto &TC =
445      static_cast<const toolchains::CudaToolChain &>(getToolChain());
446  assert(TC.getTriple().isNVPTX() && "Wrong platform");
447
448  ArgStringList CmdArgs;
449  if (TC.CudaInstallation.version() <= CudaVersion::CUDA_100)
450    CmdArgs.push_back("--cuda");
451  CmdArgs.push_back(TC.getTriple().isArch64Bit() ? "-64" : "-32");
452  CmdArgs.push_back(Args.MakeArgString("--create"));
453  CmdArgs.push_back(Args.MakeArgString(Output.getFilename()));
454  if (mustEmitDebugInfo(Args) == EmitSameDebugInfoAsHost)
455    CmdArgs.push_back("-g");
456
457  for (const auto& II : Inputs) {
458    auto *A = II.getAction();
459    assert(A->getInputs().size() == 1 &&
460           "Device offload action is expected to have a single input");
461    const char *gpu_arch_str = A->getOffloadingArch();
462    assert(gpu_arch_str &&
463           "Device action expected to have associated a GPU architecture!");
464    CudaArch gpu_arch = StringToCudaArch(gpu_arch_str);
465
466    if (II.getType() == types::TY_PP_Asm &&
467        !shouldIncludePTX(Args, gpu_arch_str))
468      continue;
469    // We need to pass an Arch of the form "sm_XX" for cubin files and
470    // "compute_XX" for ptx.
471    const char *Arch =
472        (II.getType() == types::TY_PP_Asm)
473            ? CudaVirtualArchToString(VirtualArchForCudaArch(gpu_arch))
474            : gpu_arch_str;
475    CmdArgs.push_back(Args.MakeArgString(llvm::Twine("--image=profile=") +
476                                         Arch + ",file=" + II.getFilename()));
477  }
478
479  for (const auto& A : Args.getAllArgValues(options::OPT_Xcuda_fatbinary))
480    CmdArgs.push_back(Args.MakeArgString(A));
481
482  const char *Exec = Args.MakeArgString(TC.GetProgramPath("fatbinary"));
483  C.addCommand(std::make_unique<Command>(JA, *this, Exec, CmdArgs, Inputs));
484}
485
486void NVPTX::OpenMPLinker::ConstructJob(Compilation &C, const JobAction &JA,
487                                       const InputInfo &Output,
488                                       const InputInfoList &Inputs,
489                                       const ArgList &Args,
490                                       const char *LinkingOutput) const {
491  const auto &TC =
492      static_cast<const toolchains::CudaToolChain &>(getToolChain());
493  assert(TC.getTriple().isNVPTX() && "Wrong platform");
494
495  ArgStringList CmdArgs;
496
497  // OpenMP uses nvlink to link cubin files. The result will be embedded in the
498  // host binary by the host linker.
499  assert(!JA.isHostOffloading(Action::OFK_OpenMP) &&
500         "CUDA toolchain not expected for an OpenMP host device.");
501
502  if (Output.isFilename()) {
503    CmdArgs.push_back("-o");
504    CmdArgs.push_back(Output.getFilename());
505  } else
506    assert(Output.isNothing() && "Invalid output.");
507  if (mustEmitDebugInfo(Args) == EmitSameDebugInfoAsHost)
508    CmdArgs.push_back("-g");
509
510  if (Args.hasArg(options::OPT_v))
511    CmdArgs.push_back("-v");
512
513  StringRef GPUArch =
514      Args.getLastArgValue(options::OPT_march_EQ);
515  assert(!GPUArch.empty() && "At least one GPU Arch required for ptxas.");
516
517  CmdArgs.push_back("-arch");
518  CmdArgs.push_back(Args.MakeArgString(GPUArch));
519
520  // Assume that the directory specified with --libomptarget_nvptx_path
521  // contains the static library libomptarget-nvptx.a.
522  if (const Arg *A = Args.getLastArg(options::OPT_libomptarget_nvptx_path_EQ))
523    CmdArgs.push_back(Args.MakeArgString(Twine("-L") + A->getValue()));
524
525  // Add paths specified in LIBRARY_PATH environment variable as -L options.
526  addDirectoryList(Args, CmdArgs, "-L", "LIBRARY_PATH");
527
528  // Add paths for the default clang library path.
529  SmallString<256> DefaultLibPath =
530      llvm::sys::path::parent_path(TC.getDriver().Dir);
531  llvm::sys::path::append(DefaultLibPath, "lib" CLANG_LIBDIR_SUFFIX);
532  CmdArgs.push_back(Args.MakeArgString(Twine("-L") + DefaultLibPath));
533
534  // Add linking against library implementing OpenMP calls on NVPTX target.
535  CmdArgs.push_back("-lomptarget-nvptx");
536
537  for (const auto &II : Inputs) {
538    if (II.getType() == types::TY_LLVM_IR ||
539        II.getType() == types::TY_LTO_IR ||
540        II.getType() == types::TY_LTO_BC ||
541        II.getType() == types::TY_LLVM_BC) {
542      C.getDriver().Diag(diag::err_drv_no_linker_llvm_support)
543          << getToolChain().getTripleString();
544      continue;
545    }
546
547    // Currently, we only pass the input files to the linker, we do not pass
548    // any libraries that may be valid only for the host.
549    if (!II.isFilename())
550      continue;
551
552    const char *CubinF = C.addTempFile(
553        C.getArgs().MakeArgString(getToolChain().getInputFilename(II)));
554
555    CmdArgs.push_back(CubinF);
556  }
557
558  const char *Exec =
559      Args.MakeArgString(getToolChain().GetProgramPath("nvlink"));
560  C.addCommand(std::make_unique<Command>(JA, *this, Exec, CmdArgs, Inputs));
561}
562
563/// CUDA toolchain.  Our assembler is ptxas, and our "linker" is fatbinary,
564/// which isn't properly a linker but nonetheless performs the step of stitching
565/// together object files from the assembler into a single blob.
566
567CudaToolChain::CudaToolChain(const Driver &D, const llvm::Triple &Triple,
568                             const ToolChain &HostTC, const ArgList &Args,
569                             const Action::OffloadKind OK)
570    : ToolChain(D, Triple, Args), HostTC(HostTC),
571      CudaInstallation(D, HostTC.getTriple(), Args), OK(OK) {
572  if (CudaInstallation.isValid()) {
573    CudaInstallation.WarnIfUnsupportedVersion();
574    getProgramPaths().push_back(CudaInstallation.getBinPath());
575  }
576  // Lookup binaries into the driver directory, this is used to
577  // discover the clang-offload-bundler executable.
578  getProgramPaths().push_back(getDriver().Dir);
579}
580
581std::string CudaToolChain::getInputFilename(const InputInfo &Input) const {
582  // Only object files are changed, for example assembly files keep their .s
583  // extensions. CUDA also continues to use .o as they don't use nvlink but
584  // fatbinary.
585  if (!(OK == Action::OFK_OpenMP && Input.getType() == types::TY_Object))
586    return ToolChain::getInputFilename(Input);
587
588  // Replace extension for object files with cubin because nvlink relies on
589  // these particular file names.
590  SmallString<256> Filename(ToolChain::getInputFilename(Input));
591  llvm::sys::path::replace_extension(Filename, "cubin");
592  return Filename.str();
593}
594
595void CudaToolChain::addClangTargetOptions(
596    const llvm::opt::ArgList &DriverArgs,
597    llvm::opt::ArgStringList &CC1Args,
598    Action::OffloadKind DeviceOffloadingKind) const {
599  HostTC.addClangTargetOptions(DriverArgs, CC1Args, DeviceOffloadingKind);
600
601  StringRef GpuArch = DriverArgs.getLastArgValue(options::OPT_march_EQ);
602  assert(!GpuArch.empty() && "Must have an explicit GPU arch.");
603  assert((DeviceOffloadingKind == Action::OFK_OpenMP ||
604          DeviceOffloadingKind == Action::OFK_Cuda) &&
605         "Only OpenMP or CUDA offloading kinds are supported for NVIDIA GPUs.");
606
607  if (DeviceOffloadingKind == Action::OFK_Cuda) {
608    CC1Args.push_back("-fcuda-is-device");
609
610    if (DriverArgs.hasFlag(options::OPT_fcuda_flush_denormals_to_zero,
611                           options::OPT_fno_cuda_flush_denormals_to_zero, false))
612      CC1Args.push_back("-fcuda-flush-denormals-to-zero");
613
614    if (DriverArgs.hasFlag(options::OPT_fcuda_approx_transcendentals,
615                           options::OPT_fno_cuda_approx_transcendentals, false))
616      CC1Args.push_back("-fcuda-approx-transcendentals");
617
618    if (DriverArgs.hasFlag(options::OPT_fgpu_rdc, options::OPT_fno_gpu_rdc,
619                           false))
620      CC1Args.push_back("-fgpu-rdc");
621  }
622
623  if (DriverArgs.hasArg(options::OPT_nogpulib))
624    return;
625
626  std::string LibDeviceFile = CudaInstallation.getLibDeviceFile(GpuArch);
627
628  if (LibDeviceFile.empty()) {
629    if (DeviceOffloadingKind == Action::OFK_OpenMP &&
630        DriverArgs.hasArg(options::OPT_S))
631      return;
632
633    getDriver().Diag(diag::err_drv_no_cuda_libdevice) << GpuArch;
634    return;
635  }
636
637  CC1Args.push_back("-mlink-builtin-bitcode");
638  CC1Args.push_back(DriverArgs.MakeArgString(LibDeviceFile));
639
640  // New CUDA versions often introduce new instructions that are only supported
641  // by new PTX version, so we need to raise PTX level to enable them in NVPTX
642  // back-end.
643  const char *PtxFeature = nullptr;
644  switch(CudaInstallation.version()) {
645    case CudaVersion::CUDA_101:
646      PtxFeature = "+ptx64";
647      break;
648    case CudaVersion::CUDA_100:
649      PtxFeature = "+ptx63";
650      break;
651    case CudaVersion::CUDA_92:
652      PtxFeature = "+ptx61";
653      break;
654    case CudaVersion::CUDA_91:
655      PtxFeature = "+ptx61";
656      break;
657    case CudaVersion::CUDA_90:
658      PtxFeature = "+ptx60";
659      break;
660    default:
661      PtxFeature = "+ptx42";
662  }
663  CC1Args.append({"-target-feature", PtxFeature});
664  if (DriverArgs.hasFlag(options::OPT_fcuda_short_ptr,
665                         options::OPT_fno_cuda_short_ptr, false))
666    CC1Args.append({"-mllvm", "--nvptx-short-ptr"});
667
668  if (CudaInstallation.version() >= CudaVersion::UNKNOWN)
669    CC1Args.push_back(DriverArgs.MakeArgString(
670        Twine("-target-sdk-version=") +
671        CudaVersionToString(CudaInstallation.version())));
672
673  if (DeviceOffloadingKind == Action::OFK_OpenMP) {
674    SmallVector<StringRef, 8> LibraryPaths;
675    if (const Arg *A = DriverArgs.getLastArg(options::OPT_libomptarget_nvptx_path_EQ))
676      LibraryPaths.push_back(A->getValue());
677
678    // Add user defined library paths from LIBRARY_PATH.
679    llvm::Optional<std::string> LibPath =
680        llvm::sys::Process::GetEnv("LIBRARY_PATH");
681    if (LibPath) {
682      SmallVector<StringRef, 8> Frags;
683      const char EnvPathSeparatorStr[] = {llvm::sys::EnvPathSeparator, '\0'};
684      llvm::SplitString(*LibPath, Frags, EnvPathSeparatorStr);
685      for (StringRef Path : Frags)
686        LibraryPaths.emplace_back(Path.trim());
687    }
688
689    // Add path to lib / lib64 folder.
690    SmallString<256> DefaultLibPath =
691        llvm::sys::path::parent_path(getDriver().Dir);
692    llvm::sys::path::append(DefaultLibPath, Twine("lib") + CLANG_LIBDIR_SUFFIX);
693    LibraryPaths.emplace_back(DefaultLibPath.c_str());
694
695    std::string LibOmpTargetName =
696      "libomptarget-nvptx-" + GpuArch.str() + ".bc";
697    bool FoundBCLibrary = false;
698    for (StringRef LibraryPath : LibraryPaths) {
699      SmallString<128> LibOmpTargetFile(LibraryPath);
700      llvm::sys::path::append(LibOmpTargetFile, LibOmpTargetName);
701      if (llvm::sys::fs::exists(LibOmpTargetFile)) {
702        CC1Args.push_back("-mlink-builtin-bitcode");
703        CC1Args.push_back(DriverArgs.MakeArgString(LibOmpTargetFile));
704        FoundBCLibrary = true;
705        break;
706      }
707    }
708    if (!FoundBCLibrary)
709      getDriver().Diag(diag::warn_drv_omp_offload_target_missingbcruntime)
710          << LibOmpTargetName;
711  }
712}
713
714bool CudaToolChain::supportsDebugInfoOption(const llvm::opt::Arg *A) const {
715  const Option &O = A->getOption();
716  return (O.matches(options::OPT_gN_Group) &&
717          !O.matches(options::OPT_gmodules)) ||
718         O.matches(options::OPT_g_Flag) ||
719         O.matches(options::OPT_ggdbN_Group) || O.matches(options::OPT_ggdb) ||
720         O.matches(options::OPT_gdwarf) || O.matches(options::OPT_gdwarf_2) ||
721         O.matches(options::OPT_gdwarf_3) || O.matches(options::OPT_gdwarf_4) ||
722         O.matches(options::OPT_gdwarf_5) ||
723         O.matches(options::OPT_gcolumn_info);
724}
725
726void CudaToolChain::adjustDebugInfoKind(
727    codegenoptions::DebugInfoKind &DebugInfoKind, const ArgList &Args) const {
728  switch (mustEmitDebugInfo(Args)) {
729  case DisableDebugInfo:
730    DebugInfoKind = codegenoptions::NoDebugInfo;
731    break;
732  case DebugDirectivesOnly:
733    DebugInfoKind = codegenoptions::DebugDirectivesOnly;
734    break;
735  case EmitSameDebugInfoAsHost:
736    // Use same debug info level as the host.
737    break;
738  }
739}
740
741void CudaToolChain::AddCudaIncludeArgs(const ArgList &DriverArgs,
742                                       ArgStringList &CC1Args) const {
743  // Check our CUDA version if we're going to include the CUDA headers.
744  if (!DriverArgs.hasArg(options::OPT_nocudainc) &&
745      !DriverArgs.hasArg(options::OPT_no_cuda_version_check)) {
746    StringRef Arch = DriverArgs.getLastArgValue(options::OPT_march_EQ);
747    assert(!Arch.empty() && "Must have an explicit GPU arch.");
748    CudaInstallation.CheckCudaVersionSupportsArch(StringToCudaArch(Arch));
749  }
750  CudaInstallation.AddCudaIncludeArgs(DriverArgs, CC1Args);
751}
752
753llvm::opt::DerivedArgList *
754CudaToolChain::TranslateArgs(const llvm::opt::DerivedArgList &Args,
755                             StringRef BoundArch,
756                             Action::OffloadKind DeviceOffloadKind) const {
757  DerivedArgList *DAL =
758      HostTC.TranslateArgs(Args, BoundArch, DeviceOffloadKind);
759  if (!DAL)
760    DAL = new DerivedArgList(Args.getBaseArgs());
761
762  const OptTable &Opts = getDriver().getOpts();
763
764  // For OpenMP device offloading, append derived arguments. Make sure
765  // flags are not duplicated.
766  // Also append the compute capability.
767  if (DeviceOffloadKind == Action::OFK_OpenMP) {
768    for (Arg *A : Args) {
769      bool IsDuplicate = false;
770      for (Arg *DALArg : *DAL) {
771        if (A == DALArg) {
772          IsDuplicate = true;
773          break;
774        }
775      }
776      if (!IsDuplicate)
777        DAL->append(A);
778    }
779
780    StringRef Arch = DAL->getLastArgValue(options::OPT_march_EQ);
781    if (Arch.empty())
782      DAL->AddJoinedArg(nullptr, Opts.getOption(options::OPT_march_EQ),
783                        CLANG_OPENMP_NVPTX_DEFAULT_ARCH);
784
785    return DAL;
786  }
787
788  for (Arg *A : Args) {
789    if (A->getOption().matches(options::OPT_Xarch__)) {
790      // Skip this argument unless the architecture matches BoundArch
791      if (BoundArch.empty() || A->getValue(0) != BoundArch)
792        continue;
793
794      unsigned Index = Args.getBaseArgs().MakeIndex(A->getValue(1));
795      unsigned Prev = Index;
796      std::unique_ptr<Arg> XarchArg(Opts.ParseOneArg(Args, Index));
797
798      // If the argument parsing failed or more than one argument was
799      // consumed, the -Xarch_ argument's parameter tried to consume
800      // extra arguments. Emit an error and ignore.
801      //
802      // We also want to disallow any options which would alter the
803      // driver behavior; that isn't going to work in our model. We
804      // use isDriverOption() as an approximation, although things
805      // like -O4 are going to slip through.
806      if (!XarchArg || Index > Prev + 1) {
807        getDriver().Diag(diag::err_drv_invalid_Xarch_argument_with_args)
808            << A->getAsString(Args);
809        continue;
810      } else if (XarchArg->getOption().hasFlag(options::DriverOption)) {
811        getDriver().Diag(diag::err_drv_invalid_Xarch_argument_isdriver)
812            << A->getAsString(Args);
813        continue;
814      }
815      XarchArg->setBaseArg(A);
816      A = XarchArg.release();
817      DAL->AddSynthesizedArg(A);
818    }
819    DAL->append(A);
820  }
821
822  if (!BoundArch.empty()) {
823    DAL->eraseArg(options::OPT_march_EQ);
824    DAL->AddJoinedArg(nullptr, Opts.getOption(options::OPT_march_EQ), BoundArch);
825  }
826  return DAL;
827}
828
829Tool *CudaToolChain::buildAssembler() const {
830  return new tools::NVPTX::Assembler(*this);
831}
832
833Tool *CudaToolChain::buildLinker() const {
834  if (OK == Action::OFK_OpenMP)
835    return new tools::NVPTX::OpenMPLinker(*this);
836  return new tools::NVPTX::Linker(*this);
837}
838
839void CudaToolChain::addClangWarningOptions(ArgStringList &CC1Args) const {
840  HostTC.addClangWarningOptions(CC1Args);
841}
842
843ToolChain::CXXStdlibType
844CudaToolChain::GetCXXStdlibType(const ArgList &Args) const {
845  return HostTC.GetCXXStdlibType(Args);
846}
847
848void CudaToolChain::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
849                                              ArgStringList &CC1Args) const {
850  HostTC.AddClangSystemIncludeArgs(DriverArgs, CC1Args);
851}
852
853void CudaToolChain::AddClangCXXStdlibIncludeArgs(const ArgList &Args,
854                                                 ArgStringList &CC1Args) const {
855  HostTC.AddClangCXXStdlibIncludeArgs(Args, CC1Args);
856}
857
858void CudaToolChain::AddIAMCUIncludeArgs(const ArgList &Args,
859                                        ArgStringList &CC1Args) const {
860  HostTC.AddIAMCUIncludeArgs(Args, CC1Args);
861}
862
863SanitizerMask CudaToolChain::getSupportedSanitizers() const {
864  // The CudaToolChain only supports sanitizers in the sense that it allows
865  // sanitizer arguments on the command line if they are supported by the host
866  // toolchain. The CudaToolChain will actually ignore any command line
867  // arguments for any of these "supported" sanitizers. That means that no
868  // sanitization of device code is actually supported at this time.
869  //
870  // This behavior is necessary because the host and device toolchains
871  // invocations often share the command line, so the device toolchain must
872  // tolerate flags meant only for the host toolchain.
873  return HostTC.getSupportedSanitizers();
874}
875
876VersionTuple CudaToolChain::computeMSVCVersion(const Driver *D,
877                                               const ArgList &Args) const {
878  return HostTC.computeMSVCVersion(D, Args);
879}
880