[clang] [ClangLinkerWrapper] Use discrete steps in verbose mode (PR #204186)

[Joseph Huber via cfe-commits]

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@@ -1162,6 +1281,54 @@ std::optional<std::string> searchLibrary(StringRef Input, StringRef Root,
   return searchLibraryBaseName(Input, Root, SearchPaths);
 }
 
+/// In verbose mode we need to replay the extracted files so the user can
+/// reproduce the generated. This only prints the steps that would result in the
+/// same output files given the input.
+Error emitExtractCommands(
+    ArrayRef<SmallVector<OffloadFile>> InputsForTarget,
+    const DenseMap<StringRef, StringRef> &SourceForImage) {
+  Expected<std::string> OffloadBinaryPath = findProgram(
+      "llvm-offload-binary", {getExecutableDir("llvm-offload-binary")});
+  if (!OffloadBinaryPath)
+    return OffloadBinaryPath.takeError();
+
+  BumpPtrAllocator Alloc;
+  StringSaver Saver(Alloc);
+  MapVector<StringRef, SmallVector<StringRef>> Commands;
+  DenseSet<StringRef> Seen;
+  for (const auto &Input : InputsForTarget) {
+    for (const OffloadFile &File : Input) {
+      const OffloadBinary &Binary = *File.getBinary();
+      StringRef Identifier = Binary.getMemoryBufferRef().getBufferIdentifier();
+      StringRef Source = SourceForImage.lookup(Identifier);
+      if (Source.empty())
+        Source = Identifier;
+
+      StringRef TripleStr = Binary.getTriple();
+      StringRef Arch = Binary.getArch();
+      StringRef Kind = getOffloadKindName(Binary.getOffloadKind());
+
+      std::string ImageArg =
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jhuber6 wrote:

Yeah, this was mostly a workaround for a limitation in the `llvm-offload-binary` for archive files. Two options, either let `llvm-offload-binary` accept archive members and we extract  them all individually, or change the flow to extract it from a `.a`, turn it into a new `.a.` and pass it to the embedded job w/ `-Wl,--whole-archive`, then we can use the existing handling.

https://github.com/llvm/llvm-project/pull/204186