[llvm] Support decompressing the SHT_LLVM_BB_ADDR_MAP section. (PR #142825)

[Aiden Grossman via llvm-commits]

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@@ -782,6 +783,26 @@ decodeBBAddrMapImpl(const ELFFile<ELFT> &EF,
   if (!ContentsOrErr)
     return ContentsOrErr.takeError();
   ArrayRef<uint8_t> Content = *ContentsOrErr;
+
+  // Decompress the section if needed.
+  std::unique_ptr<uint8_t[]> DecompressedContent;
+  if (Sec.sh_flags & llvm::ELF::SHF_COMPRESSED) {
+    Expected<StringRef> SectionNameOrErr = EF.getSectionName(Sec);
+    if (!SectionNameOrErr)
+      return SectionNameOrErr.takeError();
+    auto DecompressorOrErr =
+        Decompressor::create(*SectionNameOrErr, toStringRef(*ContentsOrErr),
+                             EF.isLE(), ELFT::Is64Bits);
+    if (!DecompressorOrErr)
+      return DecompressorOrErr.takeError();
+    size_t DecompressedSize = DecompressorOrErr->getDecompressedSize();
+    DecompressedContent = std::make_unique<uint8_t[]>(DecompressedSize);
+    if (Error Err = DecompressorOrErr->decompress(
+            {DecompressedContent.get(), size_t(DecompressedSize)}))
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boomanaiden154 wrote:

The `size_t` cast seems unnecessary here given `DecompressedSize` is already `size_t`?

https://github.com/llvm/llvm-project/pull/142825