Improve PointerSize in ImageHeader

We were saving it as a raw uint32 which meant that we were having
unnecessary conversion and checks.

Bug: 329379384
Bug: 329378408
Test: art/test/testrunner/testrunner.py --host --64 --optimizing -b
Test: m test-art-host-gtest
Change-Id: Ib6d9a9abfec7588dad4ff345cc6b569df7144782

10 files changed, 23 insertions, 35 deletions

diff --git a/dex2oat/linker/image_test.cc b/dex2oat/linker/image_test.cc
index f64462e614..959264d634 100644
--- a/dex2oat/linker/image_test.cc
+++ b/dex2oat/linker/image_test.cc
@@ -19,6 +19,7 @@
 
 #include "image_test.h"
 
+#include "base/enums.h"
 #include "oat/image.h"
 #include "scoped_thread_state_change-inl.h"
 #include "thread.h"
@@ -89,8 +90,7 @@ TEST_F(ImageTest, ImageHeaderIsValid) {
                            /*boot_image_size=*/ 0u,
                            /*boot_image_component_count=*/ 0u,
                            /*boot_image_checksum=*/ 0u,
-                           sizeof(void*));
-
+                           kRuntimePointerSize);
   ASSERT_TRUE(image_header.IsValid());
 
   // Please note that for the following condition to be true, the above values should be chosen in
@@ -239,7 +239,7 @@ TEST_F(ImageTest, ImageChecksum) {
                            /*boot_image_size=*/ 0u,
                            /*boot_image_component_count=*/ 0u,
                            /*boot_image_checksum=*/ 0u,
-                           sizeof(void*));
+                           kRuntimePointerSize);
     ASSERT_TRUE(image_header.IsValid());
 
     std::string error_msg;
diff --git a/dex2oat/linker/image_writer.cc b/dex2oat/linker/image_writer.cc
index 78d5eca68f..998b48b87a 100644
--- a/dex2oat/linker/image_writer.cc
+++ b/dex2oat/linker/image_writer.cc
@@ -2808,7 +2808,7 @@ void ImageWriter::CreateHeader(size_t oat_index, size_t component_count) {
       boot_image_size_,
       boot_image_components,
       boot_image_checksums,
-      static_cast<uint32_t>(target_ptr_size_));
+      target_ptr_size_);
 }
 
 ArtMethod* ImageWriter::GetImageMethodAddress(ArtMethod* method) {
diff --git a/libartbase/base/enums.h b/libartbase/base/enums.h
index c5fb880ba5..6f4405d7b6 100644
--- a/libartbase/base/enums.h
+++ b/libartbase/base/enums.h
@@ -18,11 +18,12 @@
 #define ART_LIBARTBASE_BASE_ENUMS_H_
 
 #include <cstddef>
+#include <cstdint>
 #include <iosfwd>
 
 namespace art {
 
-enum class PointerSize : size_t {
+enum class PointerSize : uint32_t {
   k32 = 4,
   k64 = 8
 };
diff --git a/libartbase/base/utils.h b/libartbase/base/utils.h
index 5e04cb0074..106c65a2ca 100644
--- a/libartbase/base/utils.h
+++ b/libartbase/base/utils.h
@@ -88,10 +88,6 @@ inline bool TestBitmap(size_t idx, const uint8_t* bitmap) {
   return ((bitmap[idx / kBitsPerByte] >> (idx % kBitsPerByte)) & 0x01) != 0;
 }
 
-static inline constexpr bool ValidPointerSize(size_t pointer_size) {
-  return pointer_size == 4 || pointer_size == 8;
-}
-
 static inline const void* EntryPointToCodePointer(const void* entry_point) {
   uintptr_t code = reinterpret_cast<uintptr_t>(entry_point);
   // TODO: Make this Thumb2 specific. It is benign on other architectures as code is always at
@@ -133,16 +129,6 @@ bool IsKernelVersionAtLeast(int reqd_major, int reqd_minor);
 // On some old kernels, a cache operation may segfault.
 WARN_UNUSED bool CacheOperationsMaySegFault();
 
-template <typename T>
-constexpr PointerSize ConvertToPointerSize(T any) {
-  if (any == 4 || any == 8) {
-    return static_cast<PointerSize>(any);
-  } else {
-    LOG(FATAL);
-    UNREACHABLE();
-  }
-}
-
 // Return -1 if <, 0 if ==, 1 if >.
 template <typename T>
 inline static int32_t Compare(T lhs, T rhs) {
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index ff5803e69f..ecd15ba8f0 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -32,6 +32,7 @@
 #include <utility>
 #include <vector>
 
+#include "android-base/macros.h"
 #include "android-base/stringprintf.h"
 #include "android-base/strings.h"
 #include "art_field-inl.h"
@@ -40,6 +41,7 @@
 #include "base/arena_allocator.h"
 #include "base/arena_bit_vector.h"
 #include "base/casts.h"
+#include "base/enums.h"
 #include "base/file_utils.h"
 #include "base/hash_map.h"
 #include "base/hash_set.h"
@@ -1301,12 +1303,13 @@ bool ClassLinker::InitFromBootImage(std::string* error_msg) {
   std::vector<gc::space::ImageSpace*> spaces = heap->GetBootImageSpaces();
   CHECK(!spaces.empty());
   const ImageHeader& image_header = spaces[0]->GetImageHeader();
-  uint32_t pointer_size_unchecked = image_header.GetPointerSizeUnchecked();
-  if (!ValidPointerSize(pointer_size_unchecked)) {
-    *error_msg = StringPrintf("Invalid image pointer size: %u", pointer_size_unchecked);
+  image_pointer_size_ = image_header.GetPointerSize();
+  if (UNLIKELY(image_pointer_size_ != PointerSize::k32 &&
+               image_pointer_size_ != PointerSize::k64)) {
+    *error_msg =
+        StringPrintf("Invalid image pointer size: %u", static_cast<uint32_t>(image_pointer_size_));
     return false;
   }
-  image_pointer_size_ = image_header.GetPointerSize();
   if (!runtime->IsAotCompiler()) {
     // Only the Aot compiler supports having an image with a different pointer size than the
     // runtime. This happens on the host for compiling 32 bit tests since we use a 64 bit libart
diff --git a/runtime/gc/collector/immune_spaces_test.cc b/runtime/gc/collector/immune_spaces_test.cc
index 6cc7e307af..5bc3ac83b3 100644
--- a/runtime/gc/collector/immune_spaces_test.cc
+++ b/runtime/gc/collector/immune_spaces_test.cc
@@ -17,6 +17,7 @@
 #include <sys/mman.h>
 
 #include "base/common_art_test.h"
+#include "base/enums.h"
 #include "base/utils.h"
 #include "gc/collector/immune_spaces.h"
 #include "gc/space/image_space.h"
@@ -151,7 +152,7 @@ class ImmuneSpacesTest : public CommonArtTest {
         /*boot_image_size=*/ 0u,
         /*boot_image_component_count=*/ 0u,
         /*boot_image_checksum=*/ 0u,
-        /*pointer_size=*/ sizeof(void*));
+        /*pointer_size=*/ kRuntimePointerSize);
     return new FakeImageSpace(std::move(image_map),
                               std::move(live_bitmap),
                               std::move(oat_file),
diff --git a/runtime/mirror/class.h b/runtime/mirror/class.h
index b69086c971..13e328da63 100644
--- a/runtime/mirror/class.h
+++ b/runtime/mirror/class.h
@@ -59,7 +59,7 @@ class ImTable;
 enum InvokeType : uint32_t;
 template <typename Iter> class IterationRange;
 template<typename T> class LengthPrefixedArray;
-enum class PointerSize : size_t;
+enum class PointerSize : uint32_t;
 class Signature;
 template<typename T> class StrideIterator;
 template<size_t kNumReferences> class PACKED(4) StackHandleScope;
diff --git a/runtime/oat/image.cc b/runtime/oat/image.cc
index a7ac8e0ebd..e801aff1e6 100644
--- a/runtime/oat/image.cc
+++ b/runtime/oat/image.cc
@@ -52,7 +52,7 @@ ImageHeader::ImageHeader(uint32_t image_reservation_size,
                          uint32_t boot_image_size,
                          uint32_t boot_image_component_count,
                          uint32_t boot_image_checksum,
-                         uint32_t pointer_size)
+                         PointerSize pointer_size)
   : image_reservation_size_(image_reservation_size),
     component_count_(component_count),
     image_begin_(image_begin),
@@ -78,7 +78,8 @@ ImageHeader::ImageHeader(uint32_t image_reservation_size,
     CHECK_LT(oat_data_begin, oat_data_end);
     CHECK_LE(oat_data_end, oat_file_end);
   }
-  CHECK(ValidPointerSize(pointer_size_)) << pointer_size_;
+  static_assert(sizeof(PointerSize) == sizeof(uint32_t),
+                "PointerSize class is expected to be a uint32_t for the header");
   memcpy(magic_, kImageMagic, sizeof(kImageMagic));
   memcpy(version_, kImageVersion, sizeof(kImageVersion));
   std::copy_n(sections, kSectionCount, sections_);
@@ -196,7 +197,7 @@ void ImageHeader::VisitObjects(ObjectVisitor* visitor,
 }
 
 PointerSize ImageHeader::GetPointerSize() const {
-  return ConvertToPointerSize(pointer_size_);
+  return pointer_size_;
 }
 
 bool LZ4_decompress_safe_checked(const char* source,
diff --git a/runtime/oat/image.h b/runtime/oat/image.h
index 23c92a1aa8..b605ecd403 100644
--- a/runtime/oat/image.h
+++ b/runtime/oat/image.h
@@ -144,7 +144,7 @@ class PACKED(8) ImageHeader {
                      uint32_t boot_image_size,
                      uint32_t boot_image_component_count,
                      uint32_t boot_image_checksum,
-                     uint32_t pointer_size);
+                     PointerSize pointer_size);
 
   EXPORT bool IsValid() const;
   EXPORT const char* GetMagic() const;
@@ -201,10 +201,6 @@ class PACKED(8) ImageHeader {
 
   EXPORT PointerSize GetPointerSize() const;
 
-  uint32_t GetPointerSizeUnchecked() const {
-    return pointer_size_;
-  }
-
   static std::string GetOatLocationFromImageLocation(const std::string& image) {
     return GetLocationFromImageLocation(image, "oat");
   }
@@ -502,7 +498,7 @@ class PACKED(8) ImageHeader {
   uint32_t image_roots_ = 0u;
 
   // Pointer size, this affects the size of the ArtMethods.
-  uint32_t pointer_size_ = 0u;
+  PointerSize pointer_size_;
 
   // Image section sizes/offsets correspond to the uncompressed form.
   ImageSection sections_[kSectionCount];
diff --git a/runtime/runtime_image.cc b/runtime/runtime_image.cc
index 5d304698bf..276c901fc4 100644
--- a/runtime/runtime_image.cc
+++ b/runtime/runtime_image.cc
@@ -164,7 +164,7 @@ class RuntimeImageHelper {
         heap->GetBootImagesSize(),
         boot_image_components,
         boot_image_checksums,
-        static_cast<uint32_t>(kRuntimePointerSize));
+        kRuntimePointerSize);
 
     // Data size includes everything except the bitmap and the header.
     header_.data_size_ = sections_end - sizeof(ImageHeader);