[llvm-readobj] [Object] [NFC] Introduce inline helpers for chpe_range_entry.

[jacek]

Summary

As suggested in D149095.

[jhenderson]

llvm/include/llvm/Object/COFF.h

757–758

Possibly worth a unittest for each of these in ObjectTests?

[jacek]

Added a test.

[jhenderson]

LGTM.

llvm/include/llvm/Object/COFF.h

struct chpe_metadata {
   support::ulittle32_t GetX64InformationFunctionPointer;
   support::ulittle32_t SetX64InformationFunctionPointer;
   support::ulittle32_t ExtraRFETable;
   support::ulittle32_t ExtraRFETableSize;
   support::ulittle32_t __os_arm64x_dispatch_fptr;
   support::ulittle32_t AuxiliaryIATCopy;
 };
 
+enum chpe_range_type { Arm64 = 0, Arm64EC = 1, Amd64 = 2 };
+
 struct chpe_range_entry {
   support::ulittle32_t StartOffset;
   support::ulittle32_t Length;
-};
 
-enum chpe_range_type { CHPE_RANGE_ARM64, CHPE_RANGE_ARM64EC, CHPE_RANGE_AMD64 };
+  // The two low bits of StartOffset contain a range type.
+  static constexpr uint32_t TypeMask = 3;
+
+  uint32_t getStart() const { return StartOffset & ~TypeMask; }
+  uint16_t getType() const { return StartOffset & TypeMask; }
+};
 
 struct chpe_code_range_entry {
   support::ulittle32_t StartRva;
   support::ulittle32_t EndRva;
   support::ulittle32_t EntryPoint;
 };
 
 struct chpe_redirection_entry {

llvm/tools/llvm-readobj/COFFDumper.cpp

if (auto CHPE = Obj->getCHPEMetadata()) {
     if (CHPE->CodeMapCount) {
       ListScope CMLS(W, "CodeMap");
 
       uintptr_t CodeMapInt;
       if (Error E = Obj->getRvaPtr(CHPE->CodeMap, CodeMapInt))
         reportError(std::move(E), Obj->getFileName());
       auto CodeMap = reinterpret_cast<const chpe_range_entry *>(CodeMapInt);
       for (uint32_t i = 0; i < CHPE->CodeMapCount; i++) {
-        uint32_t Start = CodeMap[i].StartOffset & ~3;
+        uint32_t Start = CodeMap[i].getStart();
         W.startLine() << W.hex(Start) << " - "
                       << W.hex(Start + CodeMap[i].Length) << "  ";
-        switch (CodeMap[i].StartOffset & 3) {
-        case CHPE_RANGE_ARM64:
+        switch (CodeMap[i].getType()) {
+        case chpe_range_type::Arm64:
           W.getOStream() << "ARM64\n";
           break;
-        case CHPE_RANGE_ARM64EC:
+        case chpe_range_type::Arm64EC:
           W.getOStream() << "ARM64EC\n";
           break;
-        case CHPE_RANGE_AMD64:
+        case chpe_range_type::Amd64:
           W.getOStream() << "X64\n";
           break;
         default:
           W.getOStream() << W.hex(CodeMap[i].StartOffset & 3) << "\n";
           break;
         }
       }
     } else {

llvm/unittests/Object/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
   BinaryFormat
   Object
   ObjectYAML
   TargetParser
   )
 
 add_llvm_unittest(ObjectTests
   ArchiveTest.cpp
+  COFFObjectFileTest.cpp
   DXContainerTest.cpp
   ELFObjectFileTest.cpp
   ELFTypesTest.cpp
   ELFTest.cpp
   GOFFObjectFileTest.cpp
   MinidumpTest.cpp
   ObjectFileTest.cpp
   OffloadingTest.cpp

llvm/unittests/Object/COFFObjectFileTest.cpp

+//===- COFFObjectFileTest.cpp - Tests for COFFObjectFile ----------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Object/COFF.h"
+#include "gtest/gtest.h"
+
+using namespace llvm::object;
+
+TEST(COFFObjectFileTest, CHPERangeEntry) {
+  chpe_range_entry range;
+
+  range.StartOffset = 0x1000;
+  EXPECT_EQ(range.getStart(), 0x1000u);
+  EXPECT_EQ(range.getType(), chpe_range_type::Arm64);
+
+  range.StartOffset = 0x2000 | chpe_range_type::Arm64EC;
+  EXPECT_EQ(range.getStart(), 0x2000u);
+  EXPECT_EQ(range.getType(), chpe_range_type::Arm64EC);
+
+  range.StartOffset = 0x3000 | chpe_range_type::Amd64;
+  EXPECT_EQ(range.getStart(), 0x3000u);
+  EXPECT_EQ(range.getType(), chpe_range_type::Amd64);
+}