JonChesterfield created this revision.
JonChesterfield added reviewers: jdoerfert, ye-luo, tianshilei1992, ABataev,
grokos.
JonChesterfield requested review of this revision.
Herald added subscribers: cfe-commits, sstefan1.
Herald added a project: clang.
[libomptarget] Try a fallback devicertl if the preferred one is missing
Clang may be used with a cuda version that is newer than the clang release.
This may fail in various ways, but there is also a credible chance it will
work OK, for sufficiently small version slip.
As discussed in the weekly call, this change adds a fallback path to clang
which looks for a devicertl library that doesn't have a specific cuda version
encoded in the name, specifically 'libomptarget-nvptx-unknown.bc'. It also
warns about this, and recommends the user specify a devicertl they expect to
work manually.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D96877
Files:
clang/include/clang/Basic/DiagnosticDriverKinds.td
clang/lib/Driver/ToolChains/CommonArgs.cpp
Index: clang/lib/Driver/ToolChains/CommonArgs.cpp
===================================================================
--- clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -1628,6 +1628,33 @@
}
}
+namespace {
+bool tryAppendBuiltinBitcode(const llvm::opt::ArgList &DriverArgs,
+ llvm::opt::ArgStringList &CC1Args, StringRef lib) {
+ if (llvm::sys::fs::exists(lib)) {
+ CC1Args.push_back("-mlink-builtin-bitcode");
+ CC1Args.push_back(DriverArgs.MakeArgString(lib));
+ return true;
+ } else {
+ return false;
+ }
+}
+
+bool tryAppendBuiltinBitcodeGivenPaths(
+ const SmallVector<StringRef, 8> &LibraryPaths,
+ const llvm::opt::ArgList &DriverArgs, llvm::opt::ArgStringList &CC1Args,
+ llvm::Twine lib) {
+ for (StringRef LibraryPath : LibraryPaths) {
+ SmallString<128> TargetFile(LibraryPath);
+ llvm::sys::path::append(TargetFile, lib);
+ if (tryAppendBuiltinBitcode(DriverArgs, CC1Args, TargetFile)) {
+ return true;
+ }
+ }
+ return false;
+}
+} // namespace
+
void tools::addOpenMPDeviceRTL(const Driver &D,
const llvm::opt::ArgList &DriverArgs,
llvm::opt::ArgStringList &CC1Args,
@@ -1658,32 +1685,31 @@
// First check whether user specifies bc library
if (const Arg *A = DriverArgs.getLastArg(LibomptargetBCPathOpt)) {
std::string LibOmpTargetName(A->getValue());
- if (llvm::sys::fs::exists(LibOmpTargetName)) {
- CC1Args.push_back("-mlink-builtin-bitcode");
- CC1Args.push_back(DriverArgs.MakeArgString(LibOmpTargetName));
- } else {
+ if (!tryAppendBuiltinBitcode(DriverArgs, CC1Args, LibOmpTargetName)) {
D.Diag(diag::err_drv_omp_offload_target_bcruntime_not_found)
<< LibOmpTargetName;
}
} else {
bool FoundBCLibrary = false;
- std::string LibOmpTargetName =
- "libomptarget-" + BitcodeSuffix.str() + ".bc";
-
- for (StringRef LibraryPath : LibraryPaths) {
- SmallString<128> LibOmpTargetFile(LibraryPath);
- llvm::sys::path::append(LibOmpTargetFile, LibOmpTargetName);
- if (llvm::sys::fs::exists(LibOmpTargetFile)) {
- CC1Args.push_back("-mlink-builtin-bitcode");
- CC1Args.push_back(DriverArgs.MakeArgString(LibOmpTargetFile));
- FoundBCLibrary = true;
- break;
+ llvm::Twine LibOmpTargetName = "libomptarget-" + BitcodeSuffix + ".bc";
+ llvm::Twine FallbackTargetName =
+ "libomptarget-" + ArchPrefix + "-unknown.bc";
+
+ FoundBCLibrary = tryAppendBuiltinBitcodeGivenPaths(
+ LibraryPaths, DriverArgs, CC1Args, LibOmpTargetName);
+
+ if (!FoundBCLibrary) {
+ FoundBCLibrary = tryAppendBuiltinBitcodeGivenPaths(
+ LibraryPaths, DriverArgs, CC1Args, FallbackTargetName);
+ if (FoundBCLibrary) {
+ D.Diag(diag::warn_drv_omp_offload_target_missingbcruntime)
+ << LibOmpTargetName.str() << FallbackTargetName.str() << ArchPrefix;
}
}
if (!FoundBCLibrary)
D.Diag(diag::err_drv_omp_offload_target_missingbcruntime)
- << LibOmpTargetName << ArchPrefix;
+ << LibOmpTargetName.str() << ArchPrefix;
}
}
Index: clang/include/clang/Basic/DiagnosticDriverKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticDriverKinds.td
+++ clang/include/clang/Basic/DiagnosticDriverKinds.td
@@ -262,6 +262,10 @@
"The option -fopenmp-targets must be used in conjunction with a -fopenmp option compatible with offloading, please use -fopenmp=libomp or -fopenmp=libiomp5.">;
def err_drv_omp_offload_target_missingbcruntime : Error<
"No library '%0' found in the default clang lib directory or in LIBRARY_PATH. Please use --libomptarget-%1-bc-path to specify %1 bitcode library.">;
+
+def warn_drv_omp_offload_target_missingbcruntime : Warning<"No library '%0' found in the default clang lib directory or in LIBRARY_PATH, using '%1' instead. Please use --libomptarget-%2-bc-path to specify %2 bitcode library.">;
+
+
def err_drv_omp_offload_target_bcruntime_not_found : Error<"Bitcode library '%0' does not exist.">;
def warn_drv_omp_offload_target_duplicate : Warning<
"The OpenMP offloading target '%0' is similar to target '%1' already specified - will be ignored.">,
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