libartbase: add utilities for on-device signing files

Bug: 160683548
Test: art_file_utils_test.cc
Change-Id: I17967eebda0a565c033b095fb1deb6ceeaa3760d
diff --git a/libartbase/base/file_utils.cc b/libartbase/base/file_utils.cc
index 152900a..56382fb 100644
--- a/libartbase/base/file_utils.cc
+++ b/libartbase/base/file_utils.cc
@@ -38,9 +38,10 @@
 #endif
 #endif
 
-
 #include <memory>
+#include <sstream>
 
+#include "android-base/file.h"
 #include "android-base/stringprintf.h"
 #include "android-base/strings.h"
 
@@ -65,7 +66,6 @@
 using android::base::StringPrintf;
 
 static constexpr const char* kClassesDex = "classes.dex";
-static constexpr const char* kApexDefaultPath = "/apex/";
 static constexpr const char* kAndroidRootEnvVar = "ANDROID_ROOT";
 static constexpr const char* kAndroidRootDefaultPath = "/system";
 static constexpr const char* kAndroidSystemExtRootEnvVar = "ANDROID_SYSTEM_EXT";
@@ -75,6 +75,8 @@
 static constexpr const char* kAndroidArtRootEnvVar = "ANDROID_ART_ROOT";
 static constexpr const char* kAndroidConscryptRootEnvVar = "ANDROID_CONSCRYPT_ROOT";
 static constexpr const char* kAndroidI18nRootEnvVar = "ANDROID_I18N_ROOT";
+static constexpr const char* kApexDefaultPath = "/apex/";
+static constexpr const char* kArtApexDataEnvVar = "ART_APEX_DATA";
 
 // Get the "root" directory containing the "lib" directory where this instance
 // of the libartbase library (which contains `GetRootContainingLibartbase`) is
@@ -174,9 +176,11 @@
   return android_dir;
 }
 
-static const char* GetAndroidDir(const char* env_var, const char* default_dir) {
+static const char* GetAndroidDir(const char* env_var,
+                                 const char* default_dir,
+                                 bool must_exist = true) {
   std::string error_msg;
-  const char* dir = GetAndroidDirSafe(env_var, default_dir, /* must_exist= */ true, &error_msg);
+  const char* dir = GetAndroidDirSafe(env_var, default_dir, must_exist, &error_msg);
   if (dir != nullptr) {
     return dir;
   } else {
@@ -275,14 +279,74 @@
   return GetAndroidDir(kAndroidDataEnvVar, kAndroidDataDefaultPath);
 }
 
+std::string GetArtApexData() {
+  return GetAndroidDir(kArtApexDataEnvVar, kArtApexDataDefaultPath, /*must_exist=*/false);
+}
+
+static std::string GetFirstBootClasspathExtensionJar(const std::string& android_root) {
+  DCHECK(kIsTargetBuild);
+
+  // This method finds the first non-APEX DEX file in the boot class path as defined by the
+  // DEX2OATBOOTCLASSPATH environment variable. This corresponds to the first boot classpath
+  // extension (see IMAGE SECTION documentation in image.h). When on-device signing is used the
+  // boot class extensions are compiled together as a single image with a name derived from the
+  // first extension. This first boot classpath extension is usually
+  // '/system/framework/framework.jar'.
+  //
+  // DEX2OATBOOTCLASSPATH is generated at build time by in the init.environ.rc.in:
+  //   ${ANDROID_BUILD_TOP}/system/core/rootdir/Android.mk
+  // and initialized on Android by init in init.environ.rc:
+  //   ${ANDROID_BUILD_TOP}/system/core/rootdir/init.environ.rc.in.
+  // It is used by installd too.
+  const char* bcp = getenv("DEX2OATBOOTCLASSPATH");
+  const std::string kDefaultBcpExtensionJar = android_root + "/framework/framework.jar";
+  if (bcp != nullptr) {
+    for (std::string_view component : SplitString(bcp, ':')) {
+      if (component.empty()) {
+        continue;
+      }
+      if (!LocationIsOnApex(component)) {
+        return std::string{component};
+      }
+    }
+  }
+  return kDefaultBcpExtensionJar;
+}
+
 std::string GetDefaultBootImageLocation(const std::string& android_root) {
+  constexpr static const char* kJavalibBootArt = "javalib/boot.art";
+  constexpr static const char* kEtcBootImageProf = "etc/boot-image.prof";
+
   // Boot image consists of two parts:
-  //  - the primary boot image in the ART apex (contains the Core Libraries)
-  //  - the boot image extension on the system partition (contains framework libraries)
-  return StringPrintf("%s/javalib/boot.art:%s/framework/boot-framework.art!%s/etc/boot-image.prof",
+  //  - the primary boot image in the ART APEX (contains the Core Libraries)
+  //  - the boot image extensions (contains framework libraries) on the system partition, or
+  //    in the ART APEX data directory, if an update for the ART module has been been installed.
+  if (kIsTargetBuild) {
+    // If the ART APEX has been updated, the compiled boot image extension will be in the ART APEX
+    // data directory (assuming there is space). Otherwise, for a factory installed ART APEX it is
+    // under $ANDROID_ROOT/framework/.
+    const std::string first_extension_jar{GetFirstBootClasspathExtensionJar(android_root)};
+    const std::string boot_extension_image = GetApexDataBootImage(first_extension_jar);
+    const std::string boot_extension_filename =
+        GetSystemImageFilename(boot_extension_image.c_str(), kRuntimeISA);
+    if (OS::FileExists(boot_extension_filename.c_str(), /*check_file_type=*/true)) {
+      return StringPrintf("%s/%s:%s!%s/%s",
+                          kAndroidArtApexDefaultPath,
+                          kJavalibBootArt,
+                          boot_extension_image.c_str(),
+                          android_root.c_str(),
+                          kEtcBootImageProf);
+    } else if (errno == EACCES) {
+      // Additional warning for potential SELinux misconfiguration.
+      PLOG(ERROR) << "Default boot image check failed, could not stat: " << boot_extension_image;
+    }
+  }
+  return StringPrintf("%s/%s:%s/framework/boot-framework.art!%s/%s",
                       kAndroidArtApexDefaultPath,
+                      kJavalibBootArt,
                       android_root.c_str(),
-                      android_root.c_str());
+                      android_root.c_str(),
+                      kEtcBootImageProf);
 }
 
 std::string GetDefaultBootImageLocation(std::string* error_msg) {
@@ -293,6 +357,17 @@
   return GetDefaultBootImageLocation(android_root);
 }
 
+static std::string GetDalvikCacheDirectory(std::string_view root_directory,
+                                           std::string_view sub_directory = {}) {
+  static constexpr std::string_view kDalvikCache = "dalvik-cache";
+  std::stringstream oss;
+  oss << root_directory << '/' << kDalvikCache;
+  if (!sub_directory.empty()) {
+    oss << '/' << sub_directory;
+  }
+  return oss.str();
+}
+
 void GetDalvikCache(const char* subdir, const bool create_if_absent, std::string* dalvik_cache,
                     bool* have_android_data, bool* dalvik_cache_exists, bool* is_global_cache) {
 #ifdef _WIN32
@@ -315,7 +390,7 @@
   } else {
     *have_android_data = true;
   }
-  const std::string dalvik_cache_root = android_data + "/dalvik-cache";
+  const std::string dalvik_cache_root = GetDalvikCacheDirectory(android_data);
   *dalvik_cache = dalvik_cache_root + '/' + subdir;
   *dalvik_cache_exists = OS::DirectoryExists(dalvik_cache->c_str());
   *is_global_cache = (android_data == kAndroidDataDefaultPath);
@@ -327,18 +402,6 @@
 #endif
 }
 
-std::string GetDalvikCache(const char* subdir) {
-  CHECK(subdir != nullptr);
-  std::string android_data = GetAndroidData();
-  const std::string dalvik_cache_root = android_data + "/dalvik-cache";
-  const std::string dalvik_cache = dalvik_cache_root + '/' + subdir;
-  if (!OS::DirectoryExists(dalvik_cache.c_str())) {
-    // TODO: Check callers. Traditional behavior is to not abort.
-    return "";
-  }
-  return dalvik_cache;
-}
-
 bool GetDalvikCacheFilename(const char* location, const char* cache_location,
                             std::string* filename, std::string* error_msg) {
   if (location[0] != '/') {
@@ -357,6 +420,68 @@
   return true;
 }
 
+static std::string GetApexDataDalvikCacheDirectory(InstructionSet isa) {
+  if (isa != InstructionSet::kNone) {
+    return GetDalvikCacheDirectory(GetArtApexData(), GetInstructionSetString(isa));
+  }
+  return GetDalvikCacheDirectory(GetArtApexData());
+}
+
+static std::string GetApexDataDalvikCacheFilename(std::string_view dex_location,
+                                                  InstructionSet isa,
+                                                  bool encode_location,
+                                                  std::string_view file_extension) {
+  if (LocationIsOnApex(dex_location)) {
+    return {};
+  }
+  std::string apex_data_dalvik_cache = GetApexDataDalvikCacheDirectory(isa);
+  if (encode_location) {
+    // Arguments: "/system/framework/xyz.jar", "arm", true, "odex"
+    // Result:
+    // "/data/misc/apexdata/com.android.art/dalvik-cache/arm/system@framework@xyz.jar@classes.odex"
+    std::string result, unused_error_msg;
+    GetDalvikCacheFilename(std::string{dex_location}.c_str(),
+                           apex_data_dalvik_cache.c_str(),
+                           &result,
+                           &unused_error_msg);
+    return ReplaceFileExtension(result, file_extension);
+  } else {
+    // Arguments: "/system/framework/xyz.jar", "x86_64", false, "art"
+    // Results: "/data/misc/apexdata/com.android.art/dalvik-cache/x86_64/boot-xyz.jar@classes.art"
+    std::string basename = android::base::Basename(std::string{dex_location});
+    return apex_data_dalvik_cache + "/boot-" + ReplaceFileExtension(basename, file_extension);
+  }
+}
+
+std::string GetApexDataOatFilename(std::string_view location, InstructionSet isa) {
+  return GetApexDataDalvikCacheFilename(location, isa, /*encode_location=*/false, "oat");
+}
+
+std::string GetApexDataOdexFilename(std::string_view location, InstructionSet isa) {
+  return GetApexDataDalvikCacheFilename(location, isa, /*encode_location=*/true, "odex");
+}
+
+std::string GetApexDataBootImage(std::string_view dex_location) {
+  return GetApexDataDalvikCacheFilename(dex_location,
+                                        InstructionSet::kNone,
+                                        /*encode_location=*/false,
+                                        kArtImageExtension);
+}
+
+std::string GetApexDataImage(std::string_view dex_location) {
+  return GetApexDataDalvikCacheFilename(dex_location,
+                                        InstructionSet::kNone,
+                                        /*encode_location=*/true,
+                                        kArtImageExtension);
+}
+
+std::string GetApexDataDalvikCacheFilename(std::string_view dex_location,
+                                           InstructionSet isa,
+                                           std::string_view file_extension) {
+  return GetApexDataDalvikCacheFilename(
+      dex_location, isa, /*encode_location=*/true, file_extension);
+}
+
 std::string GetVdexFilename(const std::string& oat_location) {
   return ReplaceFileExtension(oat_location, "vdex");
 }
@@ -378,16 +503,25 @@
   return filename;
 }
 
-std::string ReplaceFileExtension(const std::string& filename, const std::string& new_extension) {
+std::string ReplaceFileExtension(std::string_view filename, std::string_view new_extension) {
   const size_t last_ext = filename.find_last_of("./");
+  std::string result;
   if (last_ext == std::string::npos || filename[last_ext] != '.') {
-    return filename + "." + new_extension;
+    result.reserve(filename.size() + 1 + new_extension.size());
+    result.append(filename).append(".").append(new_extension);
   } else {
-    return filename.substr(0, last_ext + 1) + new_extension;
+    result.reserve(last_ext + 1 + new_extension.size());
+    result.append(filename.substr(0, last_ext + 1)).append(new_extension);
   }
+  return result;
 }
 
-bool LocationIsOnArtModule(const char* full_path) {
+bool LocationIsOnArtApexData(std::string_view location) {
+  const std::string art_apex_data = GetArtApexData();
+  return android::base::StartsWith(location, art_apex_data);
+}
+
+bool LocationIsOnArtModule(std::string_view full_path) {
   std::string unused_error_msg;
   std::string module_path = GetArtRootSafe(/* must_exist= */ kIsTargetBuild, &unused_error_msg);
   if (module_path.empty()) {
@@ -413,7 +547,7 @@
 // All of `default_path`, `subdir` and the value of environment variable `env_var`
 // are expected to begin with a slash and not end with one. If this ever changes,
 // the path-building logic should be updated.
-static bool IsLocationOnModule(const char* full_path,
+static bool IsLocationOnModule(std::string_view full_path,
                                const char* env_var,
                                const char* default_path,
                                const char* subdir = nullptr) {
@@ -444,31 +578,31 @@
   return android::base::StartsWith(full_path, path_prefix);
 }
 
-bool LocationIsOnSystemFramework(const char* full_path) {
+bool LocationIsOnSystemFramework(std::string_view full_path) {
   return IsLocationOnModule(full_path,
                             kAndroidRootEnvVar,
                             kAndroidRootDefaultPath,
                             /* subdir= */ "framework/");
 }
 
-bool LocationIsOnSystemExtFramework(const char* full_path) {
+bool LocationIsOnSystemExtFramework(std::string_view full_path) {
   return IsLocationOnModule(full_path,
                             kAndroidSystemExtRootEnvVar,
                             kAndroidSystemExtRootDefaultPath,
                             /* subdir= */ "framework/");
 }
 
-bool LocationIsOnConscryptModule(const char* full_path) {
+bool LocationIsOnConscryptModule(std::string_view full_path) {
   return IsLocationOnModule(
       full_path, kAndroidConscryptRootEnvVar, kAndroidConscryptApexDefaultPath);
 }
 
-bool LocationIsOnI18nModule(const char* full_path) {
+bool LocationIsOnI18nModule(std::string_view full_path) {
   return IsLocationOnModule(
       full_path, kAndroidI18nRootEnvVar, kAndroidI18nApexDefaultPath);
 }
 
-bool LocationIsOnApex(const char* full_path) {
+bool LocationIsOnApex(std::string_view full_path) {
   return android::base::StartsWith(full_path, kApexDefaultPath);
 }
 
diff --git a/libartbase/base/file_utils.h b/libartbase/base/file_utils.h
index bcab288..67caaa6 100644
--- a/libartbase/base/file_utils.h
+++ b/libartbase/base/file_utils.h
@@ -28,9 +28,12 @@
 namespace art {
 
 static constexpr const char* kAndroidArtApexDefaultPath = "/apex/com.android.art";
+static constexpr const char* kArtApexDataDefaultPath = "/data/misc/apexdata/com.android.art";
 static constexpr const char* kAndroidConscryptApexDefaultPath = "/apex/com.android.conscrypt";
 static constexpr const char* kAndroidI18nApexDefaultPath = "/apex/com.android.i18n";
 
+static constexpr const char* kArtImageExtension = "art";
+
 // These methods return the Android Root, which is the historical location of
 // the Android "system" directory, containing the built Android artifacts. On
 // target, this is normally "/system". On host this is usually a directory under
@@ -62,30 +65,53 @@
 // Find $ANDROID_DATA, /data, or return an empty string.
 std::string GetAndroidDataSafe(/*out*/ std::string* error_msg);
 
+// Find $ART_APEX_DATA, /data/misc/apexdata/com.android.art, or abort.
+std::string GetArtApexData();
+
 // Returns the default boot image location (ANDROID_ROOT/framework/boot.art).
 // Returns an empty string if ANDROID_ROOT is not set.
 std::string GetDefaultBootImageLocation(std::string* error_msg);
 
-// Returns the default boot image location, based on the passed android root.
+// Returns the default boot image location, based on the passed `android_root`.
 std::string GetDefaultBootImageLocation(const std::string& android_root);
 
-// Returns the dalvik-cache location, with subdir appended. Returns the empty string if the cache
-// could not be found.
-std::string GetDalvikCache(const char* subdir);
-
 // Return true if we found the dalvik cache and stored it in the dalvik_cache argument.
-// have_android_data will be set to true if we have an ANDROID_DATA that exists,
-// dalvik_cache_exists will be true if there is a dalvik-cache directory that is present.
-// The flag is_global_cache tells whether this cache is /data/dalvik-cache.
+// `have_android_data` will be set to true if we have an ANDROID_DATA that exists,
+// `dalvik_cache_exists` will be true if there is a dalvik-cache directory that is present.
+// The flag `is_global_cache` tells whether this cache is /data/dalvik-cache.
 void GetDalvikCache(const char* subdir, bool create_if_absent, std::string* dalvik_cache,
                     bool* have_android_data, bool* dalvik_cache_exists, bool* is_global_cache);
 
 // Returns the absolute dalvik-cache path for a DexFile or OatFile. The path returned will be
-// rooted at cache_location.
-bool GetDalvikCacheFilename(const char* file_location, const char* cache_location,
+// rooted at `cache_location`.
+bool GetDalvikCacheFilename(const char* location, const char* cache_location,
                             std::string* filename, std::string* error_msg);
 
-// Returns the system location for an image
+// Gets the oat location in the ART APEX data directory for a DEX file installed anywhere other
+// than in an APEX. Returns the oat filename if `location` is valid, empty string otherwise.
+std::string GetApexDataOatFilename(std::string_view location, InstructionSet isa);
+
+// Gets the odex location in the ART APEX data directory for a DEX file installed anywhere other
+// than in an APEX. Returns the odex filename if `location` is valid, empty string otherwise.
+std::string GetApexDataOdexFilename(std::string_view location, InstructionSet isa);
+
+// Gets the boot image in the ART APEX data directory for a DEX file installed anywhere other
+// than in an APEX. Returns the image location if `dex_location` is valid, empty string otherwise.
+std::string GetApexDataBootImage(std::string_view dex_location);
+
+// Gets the image in the ART APEX data directory for a DEX file installed installed anywhere other
+// than in an APEX. Returns the image location if `dex_location` is valid, empty string otherwise.
+std::string GetApexDataImage(std::string_view dex_location);
+
+// Gets the name of a file in the ART APEX directory dalvik-cache. This method assumes the
+// `dex_location` is for an application and that the `dex_location` is not within an APEX.
+// Returns the location of the file in the dalvik-cache
+std::string GetApexDataDalvikCacheFilename(std::string_view dex_location,
+                                           InstructionSet isa,
+                                           std::string_view file_extension);
+
+// Returns the system location for an image. This method inserts the `isa` between the
+// dirname and basename of `location`.
 std::string GetSystemImageFilename(const char* location, InstructionSet isa);
 
 // Returns the vdex filename for the given oat filename.
@@ -96,28 +122,31 @@
 // a period, and `new_extension`.
 // Example: ReplaceFileExtension("foo.bar", "abc") == "foo.abc"
 //          ReplaceFileExtension("foo", "abc") == "foo.abc"
-std::string ReplaceFileExtension(const std::string& filename, const std::string& new_extension);
+std::string ReplaceFileExtension(std::string_view filename, std::string_view new_extension);
 
 // Return whether the location is on /apex/com.android.art
-bool LocationIsOnArtModule(const char* location);
+bool LocationIsOnArtModule(std::string_view location);
+
+// Return whether the location is on /data/misc/apexdata/com.android.art/.
+bool LocationIsOnArtApexData(std::string_view location);
 
 // Return whether the location is on /apex/com.android.conscrypt
-bool LocationIsOnConscryptModule(const char* location);
+bool LocationIsOnConscryptModule(std::string_view location);
 
 // Return whether the location is on /apex/com.android.i18n
-bool LocationIsOnI18nModule(const char* location);
+bool LocationIsOnI18nModule(std::string_view location);
 
 // Return whether the location is on system (i.e. android root).
 bool LocationIsOnSystem(const char* location);
 
-// Return whether the location is on system/framework (i.e. android_root/framework).
-bool LocationIsOnSystemFramework(const char* location);
+// Return whether the location is on system/framework (i.e. $ANDROID_ROOT/framework).
+bool LocationIsOnSystemFramework(std::string_view location);
 
 // Return whether the location is on system_ext/framework
-bool LocationIsOnSystemExtFramework(const char* location);
+bool LocationIsOnSystemExtFramework(std::string_view location);
 
 // Return whether the location is on /apex/.
-bool LocationIsOnApex(const char* location);
+bool LocationIsOnApex(std::string_view location);
 
 // Compare the ART module root against android root. Returns true if they are
 // both known and distinct. This is meant to be a proxy for 'running with apex'.
diff --git a/libartbase/base/file_utils_test.cc b/libartbase/base/file_utils_test.cc
index 313754e..b7cc625 100644
--- a/libartbase/base/file_utils_test.cc
+++ b/libartbase/base/file_utils_test.cc
@@ -19,6 +19,8 @@
 #include <libgen.h>
 #include <stdlib.h>
 
+#include <optional>
+
 #include "base/stl_util.h"
 #include "common_art_test.h"
 
@@ -26,6 +28,34 @@
 
 class FileUtilsTest : public CommonArtTest {};
 
+// Helper class that removes an environment variable whilst in scope.
+class ScopedUnsetEnvironmentVariable {
+ public:
+  explicit ScopedUnsetEnvironmentVariable(const char* variable)
+      : variable_{variable}, old_value_{GetOldValue(variable)} {
+    unsetenv(variable);
+  }
+
+  ~ScopedUnsetEnvironmentVariable() {
+    if (old_value_.has_value()) {
+      static constexpr int kReplace = 1;  // tidy-issue: replace argument has libc dependent name.
+      setenv(variable_, old_value_.value().c_str(), kReplace);
+    } else {
+      unsetenv(variable_);
+    }
+  }
+
+ private:
+  static std::optional<std::string> GetOldValue(const char* variable) {
+    const char* value = getenv(variable);
+    return value != nullptr ? std::optional<std::string>{value} : std::nullopt;
+  }
+
+  const char* variable_;
+  std::optional<std::string> old_value_;
+  DISALLOW_COPY_AND_ASSIGN(ScopedUnsetEnvironmentVariable);
+};
+
 TEST_F(FileUtilsTest, GetDalvikCacheFilename) {
   std::string name;
   std::string error;
@@ -46,13 +76,6 @@
   EXPECT_EQ("/foo/system@framework@boot.oat", name);
 }
 
-TEST_F(FileUtilsTest, GetDalvikCache) {
-  EXPECT_STREQ("", GetDalvikCache("should-not-exist123").c_str());
-
-  EXPECT_STREQ((android_data_ + "/dalvik-cache/.").c_str(), GetDalvikCache(".").c_str());
-}
-
-
 TEST_F(FileUtilsTest, GetSystemImageFilename) {
   EXPECT_STREQ("/system/framework/arm/boot.art",
                GetSystemImageFilename("/system/framework/boot.art", InstructionSet::kArm).c_str());
@@ -165,4 +188,107 @@
   EXPECT_EQ("/.directory/file.vdex", ReplaceFileExtension("/.directory/file", "vdex"));
 }
 
+TEST_F(FileUtilsTest, GetApexDataOatFilename) {
+  ScopedUnsetEnvironmentVariable android_root("ANDROID_ROOT");
+  ScopedUnsetEnvironmentVariable i18n_root("ANDROID_I18N_ROOT");
+  ScopedUnsetEnvironmentVariable art_apex_data("ART_APEX_DATA");
+
+  EXPECT_EQ(GetArtApexData() + "/dalvik-cache/arm/boot-beep.oat",
+            GetApexDataOatFilename("/product/javalib/beep.jar", InstructionSet::kArm));
+
+  const std::string art_apex_jar = std::string {kAndroidArtApexDefaultPath} + "/javalib/some.jar";
+  EXPECT_EQ(std::string{}, GetApexDataOatFilename(art_apex_jar.c_str(), InstructionSet::kArm));
+
+  const std::string i18n_jar =
+      std::string {kAndroidI18nApexDefaultPath} + "/javalib/core-icu4j.jar";
+  EXPECT_EQ(std::string{}, GetApexDataOatFilename(i18n_jar, InstructionSet::kArm));
+
+  const std::string system_jar_apexdata_oat = GetArtApexData() + "/dalvik-cache/x86/boot-lace.oat";
+  EXPECT_EQ(system_jar_apexdata_oat,
+            GetApexDataOatFilename("/system/framework/lace.jar", InstructionSet::kX86));
+}
+
+TEST_F(FileUtilsTest, GetApexDataOdexFilename) {
+  ScopedUnsetEnvironmentVariable android_root("ANDROID_ROOT");
+  ScopedUnsetEnvironmentVariable art_apex_data("ART_APEX_DATA");
+
+  EXPECT_EQ(GetArtApexData() + "/dalvik-cache/arm/data@some@code.odex",
+            GetApexDataOdexFilename("/data/some/code.dex", InstructionSet::kArm));
+
+  const std::string art_apex_jar = std::string {kAndroidArtApexDefaultPath} + "/javalib/some.jar";
+  EXPECT_EQ(std::string{}, GetApexDataOdexFilename(art_apex_jar.c_str(), InstructionSet::kArm));
+
+  const std::string i18n_jar =
+      std::string {kAndroidI18nApexDefaultPath} + "/javalib/core-icu4j.jar";
+  EXPECT_EQ(std::string{}, GetApexDataOdexFilename(i18n_jar.c_str(), InstructionSet::kArm));
+
+  const std::string system_jar_apexdata_odex =
+      GetArtApexData() + "/dalvik-cache/x86/system@framework@cookie.jar@classes.odex";
+  EXPECT_EQ(system_jar_apexdata_odex,
+            GetApexDataOdexFilename("/system/framework/cookie.jar", InstructionSet::kX86));
+}
+
+TEST_F(FileUtilsTest, GetApexDataBootImage) {
+  ScopedUnsetEnvironmentVariable android_root("ANDROID_ROOT");
+  ScopedUnsetEnvironmentVariable art_apex_data("ART_APEX_DATA");
+
+  EXPECT_EQ(std::string{},
+            GetApexDataBootImage(std::string {kAndroidI18nApexDefaultPath} + "/javalib/bar.jar"));
+
+  // Check image location has the prefix "boot-" in front of the basename of dex location and
+  // that image suffix is .art.
+  const std::string system_jar = "/system/framework/disk.jar";
+  const std::string boot_image = GetApexDataBootImage(system_jar.c_str());
+  EXPECT_EQ(GetArtApexData() + "/dalvik-cache/boot-disk.art", boot_image);
+
+  // Check the image filename corresponds to the oat file for the same system jar.
+  const InstructionSet isa = InstructionSet::kArm64;
+  const std::string boot_image_filename = GetSystemImageFilename(boot_image.c_str(), isa);
+  const std::string accompanying_oat_file = ReplaceFileExtension(boot_image_filename, "oat");
+  EXPECT_EQ(accompanying_oat_file, GetApexDataOatFilename(system_jar.c_str(), isa));
+}
+
+TEST_F(FileUtilsTest, GetApexDataImage) {
+  ScopedUnsetEnvironmentVariable android_root("ANDROID_ROOT");
+  ScopedUnsetEnvironmentVariable art_apex_data("ART_APEX_DATA");
+
+  EXPECT_EQ(std::string{},
+            GetApexDataImage(std::string {kAndroidI18nApexDefaultPath} + "/lib/javalib/bar.jar"));
+
+  // Check image has basename of dex location with the .art suffix.
+  const char* jar = "/system/framework/mcguffin/test.jar";
+  const std::string image = GetApexDataImage(jar);
+  EXPECT_EQ(GetArtApexData() + "/dalvik-cache/system@framework@mcguffin@test.jar@classes.art",
+            image);
+
+  // Check the image filename corresponds to the .odex file for the same system jar.
+  const InstructionSet isa = InstructionSet::kX86_64;
+  const std::string image_filename = GetSystemImageFilename(image.c_str(), isa);
+  const std::string accompanying_odex_file = ReplaceFileExtension(image_filename, "odex");
+  EXPECT_EQ(accompanying_odex_file, GetApexDataOdexFilename(jar, isa));
+}
+
+TEST_F(FileUtilsTest, GetApexDataDalvikCacheFilename) {
+  // Check /apex inputs return empty string
+  const std::string apex_jar = std::string {kAndroidI18nApexDefaultPath} + "/lib/javalib/bar.jar";
+  EXPECT_EQ(std::string{},
+            GetApexDataDalvikCacheFilename(apex_jar, InstructionSet::kX86_64, "art"));
+
+  // Check dalvik-cache filename follows convention.
+  const std::string non_apex_jar = "/vendor/javalib/test.jar";
+  const std::string art_filename =
+      GetApexDataDalvikCacheFilename(non_apex_jar, InstructionSet::kArm, "art");
+  CHECK_EQ(GetArtApexData() + "/dalvik-cache/arm/vendor@javalib@test.jar@classes.art",
+           art_filename);
+
+  // Check ".art", ".odex" and ".vdex" filenames are the same with the appropriate extensions
+  // substituted.
+  const std::string odex_filename =
+      GetApexDataDalvikCacheFilename(non_apex_jar, InstructionSet::kArm, "odex");
+  CHECK_EQ(odex_filename, ReplaceFileExtension(art_filename, "odex"));
+  const std::string vdex_filename =
+      GetApexDataDalvikCacheFilename(non_apex_jar, InstructionSet::kArm, "vdex");
+  CHECK_EQ(vdex_filename, ReplaceFileExtension(art_filename, "vdex"));
+}
+
 }  // namespace art