1 files changed, 61 insertions, 11 deletions

diff --git a/llvm/lib/Object/SFrameParser.cpp b/llvm/lib/Object/SFrameParser.cpp
index 2d74d1d..5863490 100644
--- a/llvm/lib/Object/SFrameParser.cpp
+++ b/llvm/lib/Object/SFrameParser.cpp
@@ -10,27 +10,41 @@
 #include "llvm/BinaryFormat/SFrame.h"
 #include "llvm/Object/Error.h"
 #include "llvm/Support/FormatVariadic.h"
+#include "llvm/Support/MathExtras.h"
 
 using namespace llvm;
 using namespace llvm::object;
 
-template <typename T>
-static Expected<const T &> getDataSliceAs(ArrayRef<uint8_t> Data,
-                                          uint64_t Offset) {
-  static_assert(std::is_trivial_v<T>);
-  if (Data.size() < Offset + sizeof(T)) {
+static Expected<ArrayRef<uint8_t>>
+getDataSlice(ArrayRef<uint8_t> Data, uint64_t Offset, uint64_t Size) {
+  uint64_t End = SaturatingAdd(Offset, Size);
+  // Data.size() cannot be UINT64_MAX, as it would occupy the whole address
+  // space.
+  if (End > Data.size()) {
     return createStringError(
         formatv("unexpected end of data at offset {0:x} while reading [{1:x}, "
                 "{2:x})",
-                Data.size(), Offset, Offset + sizeof(T))
+                Data.size(), Offset, End)
             .str(),
         object_error::unexpected_eof);
   }
-  return *reinterpret_cast<const T *>(Data.data() + Offset);
+  return Data.slice(Offset, Size);
+}
+
+template <typename T>
+static Expected<const T &> getDataSliceAs(ArrayRef<uint8_t> Data,
+                                          uint64_t Offset) {
+  static_assert(std::is_trivial_v<T>);
+  Expected<ArrayRef<uint8_t>> Slice = getDataSlice(Data, Offset, sizeof(T));
+  if (!Slice)
+    return Slice.takeError();
+
+  return *reinterpret_cast<const T *>(Slice->data());
 }
 
 template <endianness E>
-Expected<SFrameParser<E>> SFrameParser<E>::create(ArrayRef<uint8_t> Contents) {
+Expected<SFrameParser<E>> SFrameParser<E>::create(ArrayRef<uint8_t> Contents,
+                                                  uint64_t SectionAddress) {
   Expected<const sframe::Preamble<E> &> Preamble =
       getDataSliceAs<sframe::Preamble<E>>(Contents, 0);
   if (!Preamble)
@@ -48,8 +62,44 @@ Expected<SFrameParser<E>> SFrameParser<E>::create(ArrayRef<uint8_t> Contents) {
       getDataSliceAs<sframe::Header<E>>(Contents, 0);
   if (!Header)
     return Header.takeError();
-  return SFrameParser(Contents, *Header);
+  return SFrameParser(Contents, SectionAddress, *Header);
+}
+
+template <endianness E>
+Expected<ArrayRef<uint8_t>> SFrameParser<E>::getAuxHeader() const {
+  return getDataSlice(Data, sizeof(Header), Header.AuxHdrLen);
+}
+
+template <endianness E>
+Expected<ArrayRef<sframe::FuncDescEntry<E>>> SFrameParser<E>::fdes() const {
+  Expected<ArrayRef<uint8_t>> Slice = getDataSlice(
+      Data, getFDEBase(), Header.NumFDEs * sizeof(sframe::FuncDescEntry<E>));
+  if (!Slice)
+    return Slice.takeError();
+  return ArrayRef(
+      reinterpret_cast<const sframe::FuncDescEntry<E> *>(Slice->data()),
+      Header.NumFDEs);
+}
+
+template <endianness E>
+uint64_t SFrameParser<E>::getAbsoluteStartAddress(
+    typename FDERange::iterator FDE) const {
+  uint64_t Result = SectionAddress + FDE->StartAddress;
+
+  if ((getPreamble().Flags.value() & sframe::Flags::FDEFuncStartPCRel) ==
+      sframe::Flags::FDEFuncStartPCRel) {
+    uintptr_t DataPtr = reinterpret_cast<uintptr_t>(Data.data());
+    uintptr_t FDEPtr = reinterpret_cast<uintptr_t>(&*FDE);
+
+    assert(DataPtr <= FDEPtr && FDEPtr < DataPtr + Data.size() &&
+           "Iterator does not belong to this object!");
+
+    Result += FDEPtr - DataPtr;
+  }
+
+  return Result;
 }
 
-template class llvm::object::SFrameParser<endianness::big>;
-template class llvm::object::SFrameParser<endianness::little>;
+template class LLVM_EXPORT_TEMPLATE llvm::object::SFrameParser<endianness::big>;
+template class LLVM_EXPORT_TEMPLATE
+    llvm::object::SFrameParser<endianness::little>;