[llvm] Fix compress/decompress in LLVM Offloading API (PR #150064)

[James Henderson via llvm-commits]

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@@ -37,26 +37,63 @@ Error extractOffloadBundle(MemoryBufferRef Contents, uint64_t SectionOffset,
 
   size_t Offset = 0;
   size_t NextbundleStart = 0;
+  StringRef Magic;
+  std::unique_ptr<MemoryBuffer> Buffer;
 
   // There could be multiple offloading bundles stored at this section.
-  while (NextbundleStart != StringRef::npos) {
-    std::unique_ptr<MemoryBuffer> Buffer =
+  while ((NextbundleStart != StringRef::npos) &&
+         (Offset < Contents.getBuffer().size())) {
+    Buffer =
         MemoryBuffer::getMemBuffer(Contents.getBuffer().drop_front(Offset), "",
                                    /*RequiresNullTerminator=*/false);
 
-    // Create the FatBinBindle object. This will also create the Bundle Entry
-    // list info.
-    auto FatBundleOrErr =
-        OffloadBundleFatBin::create(*Buffer, SectionOffset + Offset, FileName);
-    if (!FatBundleOrErr)
-      return FatBundleOrErr.takeError();
-
-    // Add current Bundle to list.
-    Bundles.emplace_back(std::move(**FatBundleOrErr));
+    if (identify_magic((*Buffer).getBuffer()) ==
+        file_magic::offload_bundle_compressed) {
+      Magic = StringRef("CCOB");
+      // decompress this bundle first.
+      NextbundleStart = (*Buffer).getBuffer().find(Magic, Magic.size());
+      if (NextbundleStart == StringRef::npos) {
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jh7370 wrote:

Nit: don't need parentheses here.

https://github.com/llvm/llvm-project/pull/150064