[llvm-xray] Add AArch64 to llvm-xray extract

[ianlevesque]

Summary

This required adding support for resolving R_AARCH64_ABS64 relocations to
get accurate addresses for function names to resolve.

[dberris]

LGTM

llvm/lib/XRay/InstrumentationMap.cpp

104

I'd suggest a different name here, maybe SupportsRelocation?

[ianlevesque]

rename Supports

[ianlevesque]

I don't have commit access, can someone land it?

[smeenai]

It seems like the commit dropped the tests. I'm planning to re-add them, and try converting the binary to YAML in the process.

[smeenai]

I converted the test to YAML and committed it as rG56cd447eec8e.

llvm/lib/XRay/InstrumentationMap.cpp

 #include "llvm/ADT/None.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/Object/Binary.h"
 #include "llvm/Object/ELFObjectFile.h"
 #include "llvm/Object/ObjectFile.h"
+#include "llvm/Object/RelocationResolver.h"
 #include "llvm/Support/DataExtractor.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/YAMLTraits.h"
 #include <algorithm>
 #include <cstddef>
 #include <cstdint>
 #include <system_error>
loadObj(StringRef Filename, object::OwningBinary<object::ObjectFile> &ObjFile,
           InstrumentationMap::SledContainer &Sleds,
           InstrumentationMap::FunctionAddressMap &FunctionAddresses,
           InstrumentationMap::FunctionAddressReverseMap &FunctionIds) {
   InstrumentationMap Map;
 
   // Find the section named "xray_instr_map".
   if ((!ObjFile.getBinary()->isELF() && !ObjFile.getBinary()->isMachO()) ||
       !(ObjFile.getBinary()->getArch() == Triple::x86_64 ||
-        ObjFile.getBinary()->getArch() == Triple::ppc64le))
+        ObjFile.getBinary()->getArch() == Triple::ppc64le ||
+        ObjFile.getBinary()->getArch() == Triple::aarch64))
     return make_error<StringError>(
         "File format not supported (only does ELF and Mach-O little endian 64-bit).",
         std::make_error_code(std::errc::not_supported));
 
   StringRef Contents = "";
   const auto &Sections = ObjFile.getBinary()->sections();
   auto I = llvm::find_if(Sections, [&](object::SectionRef Section) {
     Expected<StringRef> NameOrErr = Section.getName();
uint32_t RelativeRelocation = [](object::ObjectFile *ObjFile) {
       else if (const auto *ELFObj = dyn_cast<object::ELF64LEObjectFile>(ObjFile))
         return ELFObj->getELFFile()->getRelativeRelocationType();
       else if (const auto *ELFObj = dyn_cast<object::ELF64BEObjectFile>(ObjFile))
         return ELFObj->getELFFile()->getRelativeRelocationType();
       else
         return static_cast<uint32_t>(0);
     }(ObjFile.getBinary());
 
+    bool (*SupportsRelocation)(uint64_t);
+    object::RelocationResolver Resolver;
+    std::tie(SupportsRelocation, Resolver) =
+        object::getRelocationResolver(*ObjFile.getBinary());
+
     for (const object::SectionRef &Section : Sections) {
       for (const object::RelocationRef &Reloc : Section.relocations()) {
-        if (Reloc.getType() != RelativeRelocation)
-          continue;
+        if (SupportsRelocation && SupportsRelocation(Reloc.getType())) {
+          auto AddendOrErr = object::ELFRelocationRef(Reloc).getAddend();
+          auto A = AddendOrErr ? *AddendOrErr : 0;
+          uint64_t resolved = Resolver(Reloc, Reloc.getSymbol()->getValue(), A);
+          Relocs.insert({Reloc.getOffset(), resolved});
+        } else if (Reloc.getType() == RelativeRelocation) {
           if (auto AddendOrErr = object::ELFRelocationRef(Reloc).getAddend())
             Relocs.insert({Reloc.getOffset(), *AddendOrErr});
         }
       }
     }
+  }
 
   // Copy the instrumentation map data into the Sleds data structure.
   auto C = Contents.bytes_begin();
   static constexpr size_t ELF64SledEntrySize = 32;
 
   if ((C - Contents.bytes_end()) % ELF64SledEntrySize != 0)
     return make_error<StringError>(
         Twine("Instrumentation map entries not evenly divisible by size of "