[llvm] Implements PGOBBAddrMap in Object and ObjectYAML with tests [1/5] (PR #71750)

[Micah Weston via llvm-commits]

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@@ -645,11 +645,39 @@ ELFFile<ELFT>::toMappedAddr(uint64_t VAddr, WarningHandler WarnHandler) const {
   return base() + Offset;
 }
 
-template <class ELFT>
-Expected<std::vector<BBAddrMap>>
-ELFFile<ELFT>::decodeBBAddrMap(const Elf_Shdr &Sec,
-                               const Elf_Shdr *RelaSec) const {
-  bool IsRelocatable = getHeader().e_type == ELF::ET_REL;
+// Helper to extract and decode the next ULEB128 value as unsigned int.
+// Returns zero and sets ULEBSizeErr if the ULEB128 value exceeds the unsigned
+// int limit.
+// Also returns zero if ULEBSizeErr is already in an error state.
+// ULEBSizeErr is an out variable if an error occurs.
+template <typename IntTy>
+static IntTy readULEB128As(DataExtractor &Data, DataExtractor::Cursor &Cur,
+                           Error &ULEBSizeErr) {
+  static_assert(std::is_unsigned_v<IntTy> &&
+                    (std::numeric_limits<IntTy>::radix == 2),
+                "only use unsigned radix 2");
+  // Bail out and do not extract data if ULEBSizeErr is already set.
+  if (ULEBSizeErr)
+    return 0;
+  uint64_t Offset = Cur.tell();
+  uint64_t Value = Data.getULEB128(Cur);
+  if (Value > std::numeric_limits<IntTy>::max()) {
+    ULEBSizeErr = createError("ULEB128 value at offset 0x" +
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red1bluelost wrote:

Yes, I this is already tested in the regular BBAddrMap tests. Found at ELFObjectFileTest.cpp:564

https://github.com/llvm/llvm-project/pull/71750