[clang] [Clang] Rework creating offloading toolchains (PR #125556)

[Joseph Huber via cfe-commits]

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@@ -458,6 +400,44 @@ phases::ID Driver::getFinalPhase(const DerivedArgList &DAL,
   return FinalPhase;
 }
 
+llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>>
+Driver::executeProgram(llvm::ArrayRef<llvm::StringRef> Args) const {
+  llvm::SmallString<64> OutputFile;
+  llvm::sys::fs::createTemporaryFile("driver-program", "txt", OutputFile,
+                                     llvm::sys::fs::OF_Text);
+  llvm::FileRemover OutputRemover(OutputFile.c_str());
+  std::optional<llvm::StringRef> Redirects[] = {
+      {""},
+      OutputFile.str(),
+      {""},
+  };
+
+  std::string ErrorMessage;
+  int SecondsToWait = 60;
+  if (std::optional<std::string> Str =
+          llvm::sys::Process::GetEnv("CLANG_TOOLCHAIN_PROGRAM_TIMEOUT")) {
+    if (!llvm::to_integer(*Str, SecondsToWait))
+      return llvm::createStringError(std::error_code(),
+                                     "CLANG_TOOLCHAIN_PROGRAM_TIMEOUT expected "
+                                     "an integer, got '" +
+                                         *Str + "'");
+    SecondsToWait = std::max(SecondsToWait, 0); // infinite
+  }
+  StringRef Executable = Args[0];
+  if (llvm::sys::ExecuteAndWait(Executable, Args, {}, Redirects, SecondsToWait,
+                                /*MemoryLimit=*/0, &ErrorMessage))
+    return llvm::createStringError(std::error_code(),
+                                   Executable + ": " + ErrorMessage);
+
+  llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> OutputBuf =
+      llvm::MemoryBuffer::getFile(OutputFile.c_str());
+  if (!OutputBuf)
+    return llvm::createStringError(OutputBuf.getError(),
+                                   "Failed to read stdout of " + Executable +
----------------
jhuber6 wrote:

These were already here, could we move changing them into a follow-up?

https://github.com/llvm/llvm-project/pull/125556