Merge "Allow files generated by droidstubs to be copied in the SDK"
diff --git a/core/binary.mk b/core/binary.mk
index d9763f9..51259b2 100644
--- a/core/binary.mk
+++ b/core/binary.mk
@@ -120,8 +120,6 @@
     $(error $(LOCAL_PATH): LOCAL_SDK_VERSION cannot be used in host module)
   endif
 
-  my_cflags += -D__ANDROID_NDK__
-
   # Make sure we've built the NDK.
   my_additional_dependencies += $(SOONG_OUT_DIR)/ndk_base.timestamp
 
diff --git a/core/config.mk b/core/config.mk
index 49b9329..241ac8d 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -630,9 +630,11 @@
 USE_OPENJDK9 := true
 
 ifeq ($(EXPERIMENTAL_JAVA_LANGUAGE_LEVEL_9),)
-TARGET_OPENJDK9 :=
+TARGET_OPENJDK9 := true
 else ifeq ($(EXPERIMENTAL_JAVA_LANGUAGE_LEVEL_9),true)
 TARGET_OPENJDK9 := true
+else ifeq ($(EXPERIMENTAL_JAVA_LANGUAGE_LEVEL_9),false)
+TARGET_OPENJDK9 :=
 endif
 
 # Path to tools.jar
diff --git a/core/android_vts_host_config.mk b/core/suite_host_config.mk
similarity index 89%
rename from core/android_vts_host_config.mk
rename to core/suite_host_config.mk
index 38ba19d..d575c5b 100644
--- a/core/android_vts_host_config.mk
+++ b/core/suite_host_config.mk
@@ -16,11 +16,9 @@
 
 LOCAL_MODULE_CLASS := FAKE
 LOCAL_IS_HOST_MODULE := true
-LOCAL_COMPATIBILITY_SUITE := vts
 
 include $(BUILD_SYSTEM)/base_rules.mk
 
 $(LOCAL_BUILT_MODULE):
-	@echo "VTS host-driven test target: $(PRIVATE_MODULE)"
+	@echo "$(LOCAL_COMPATIBILITY_SUITE) host-driven test target: $(PRIVATE_MODULE)"
 	$(hide) touch $@
-
diff --git a/target/product/base_system.mk b/target/product/base_system.mk
index f49218a..7cc3270 100644
--- a/target/product/base_system.mk
+++ b/target/product/base_system.mk
@@ -364,6 +364,7 @@
     logpersist.start \
     logtagd.rc \
     procrank \
+    remount \
     showmap \
     sqlite3 \
     ss \
diff --git a/target/product/gsi/Android.mk b/target/product/gsi/Android.mk
index 93b0b15..2b288e6 100644
--- a/target/product/gsi/Android.mk
+++ b/target/product/gsi/Android.mk
@@ -154,8 +154,7 @@
     vndkprivate.libraries.txt \
     vndkcorevariant.libraries.txt \
     $(addsuffix .vendor,$(VNDK_CORE_LIBRARIES)) \
-    $(addsuffix .vendor,$(VNDK_SAMEPROCESS_LIBRARIES)) \
-    com.android.vndk.current
+    $(addsuffix .vendor,$(VNDK_SAMEPROCESS_LIBRARIES))
 endif
 include $(BUILD_PHONY_PACKAGE)
 
@@ -167,11 +166,8 @@
 _binder32 := _binder32
 endif
 endif
-# Phony targets are installed for **.libraries.txt files.
-# TODO(b/141450808): remove following VNDK phony targets when **.libraries.txt files are provided by apexes.
 LOCAL_REQUIRED_MODULES := \
     $(foreach vndk_ver,$(PRODUCT_EXTRA_VNDK_VERSIONS),vndk_v$(vndk_ver)_$(TARGET_ARCH)$(_binder32))
-LOCAL_REQUIRED_MODULES += $(foreach vndk_ver,$(PRODUCT_EXTRA_VNDK_VERSIONS),com.android.vndk.v$(vndk_ver))
 _binder32 :=
 include $(BUILD_PHONY_PACKAGE)
 
diff --git a/target/product/gsi/current.txt b/target/product/gsi/current.txt
index 3e44349..8fed53c 100644
--- a/target/product/gsi/current.txt
+++ b/target/product/gsi/current.txt
@@ -137,6 +137,7 @@
 VNDK-core: android.hardware.neuralnetworks@1.0.so
 VNDK-core: android.hardware.neuralnetworks@1.1.so
 VNDK-core: android.hardware.neuralnetworks@1.2.so
+VNDK-core: android.hardware.neuralnetworks@1.3.so
 VNDK-core: android.hardware.nfc@1.0.so
 VNDK-core: android.hardware.nfc@1.1.so
 VNDK-core: android.hardware.nfc@1.2.so
diff --git a/target/product/mainline_system.mk b/target/product/mainline_system.mk
index a71f9b8..cd6a0f7 100644
--- a/target/product/mainline_system.mk
+++ b/target/product/mainline_system.mk
@@ -78,6 +78,7 @@
     android.hardware.secure_element@1.0 \
     android.hardware.wifi@1.0 \
     libaudio-resampler \
+    libaudiohal \
     libdrm \
     liblogwrap \
     liblz4 \
diff --git a/target/product/security/Android.mk b/target/product/security/Android.mk
index 3631cfd..d6a8b53 100644
--- a/target/product/security/Android.mk
+++ b/target/product/security/Android.mk
@@ -80,30 +80,3 @@
 	    $(extra_recovery_keys)
 	$(SOONG_ZIP) -o $@ -j \
 	    $(foreach key_file, $(PRIVATE_CERT) $(PRIVATE_EXTRA_RECOVERY_KEYS), -f $(key_file))
-
-
-#######################################
-# update_engine_payload_key, used by update_engine. We use the same key as otacerts but in RSA
-# public key format.
-include $(CLEAR_VARS)
-
-LOCAL_MODULE := update_engine_payload_key
-LOCAL_MODULE_CLASS := ETC
-LOCAL_MODULE_STEM := update-payload-key.pub.pem
-LOCAL_MODULE_PATH := $(TARGET_OUT_ETC)/update_engine
-include $(BUILD_SYSTEM)/base_rules.mk
-$(LOCAL_BUILT_MODULE): $(DEFAULT_SYSTEM_DEV_CERTIFICATE).x509.pem
-	openssl x509 -pubkey -noout -in $< > $@
-
-
-#######################################
-# update_engine_payload_key for recovery image, used by update_engine.
-include $(CLEAR_VARS)
-
-LOCAL_MODULE := update_engine_payload_key.recovery
-LOCAL_MODULE_CLASS := ETC
-LOCAL_MODULE_STEM := update-payload-key.pub.pem
-LOCAL_MODULE_PATH := $(TARGET_RECOVERY_ROOT_OUT)/system/etc/update_engine
-include $(BUILD_SYSTEM)/base_rules.mk
-$(LOCAL_BUILT_MODULE): $(DEFAULT_SYSTEM_DEV_CERTIFICATE).x509.pem
-	openssl x509 -pubkey -noout -in $< > $@
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index f846b18..031db1d 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -882,7 +882,7 @@
   # boot chain, to be verified with AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION.
   # See details at
   # https://android.googlesource.com/platform/external/avb/+/master/README.md#booting-into-recovery.
-  if OPTIONS.info_dict.get("ab_update") != "true" and partition == "recovery":
+  if info_dict.get("ab_update") != "true" and partition == "recovery":
     return []
 
   # Otherwise chain the partition into vbmeta.
diff --git a/tools/releasetools/ota_from_target_files.py b/tools/releasetools/ota_from_target_files.py
index 1e7bb3a..dfcfb49 100755
--- a/tools/releasetools/ota_from_target_files.py
+++ b/tools/releasetools/ota_from_target_files.py
@@ -171,8 +171,16 @@
   --payload_signer_args <args>
       Specify the arguments needed for payload signer.
 
+  --payload_signer_maximum_signature_size <signature_size>
+      The maximum signature size (in bytes) that would be generated by the given
+      payload signer. Only meaningful when custom payload signer is specified
+      via '--payload_signer'.
+      If the signer uses a RSA key, this should be the number of bytes to
+      represent the modulus. If it uses an EC key, this is the size of a
+      DER-encoded ECDSA signature.
+
   --payload_signer_key_size <key_size>
-      Specify the key size in bytes of the payload signer.
+      Deprecated. Use the '--payload_signer_maximum_signature_size' instead.
 
   --skip_postinstall
       Skip the postinstall hooks when generating an A/B OTA package (default:
@@ -231,7 +239,7 @@
 OPTIONS.log_diff = None
 OPTIONS.payload_signer = None
 OPTIONS.payload_signer_args = []
-OPTIONS.payload_signer_key_size = None
+OPTIONS.payload_signer_maximum_signature_size = None
 OPTIONS.extracted_input = None
 OPTIONS.key_passwords = []
 OPTIONS.skip_postinstall = False
@@ -288,35 +296,31 @@
       self.signer = "openssl"
       self.signer_args = ["pkeyutl", "-sign", "-inkey", signing_key,
                           "-pkeyopt", "digest:sha256"]
-      self.key_size = self._GetKeySizeInBytes(signing_key)
+      self.maximum_signature_size = self._GetMaximumSignatureSizeInBytes(
+          signing_key)
     else:
       self.signer = OPTIONS.payload_signer
       self.signer_args = OPTIONS.payload_signer_args
-      if OPTIONS.payload_signer_key_size:
-        self.key_size = int(OPTIONS.payload_signer_key_size)
-        assert self.key_size == 256 or self.key_size == 512, \
-            "Unsupported key size {}".format(OPTIONS.payload_signer_key_size)
+      if OPTIONS.payload_signer_maximum_signature_size:
+        self.maximum_signature_size = int(
+            OPTIONS.payload_signer_maximum_signature_size)
       else:
-        self.key_size = 256
+        # The legacy config uses RSA2048 keys.
+        logger.warning("The maximum signature size for payload signer is not"
+                       " set, default to 256 bytes.")
+        self.maximum_signature_size = 256
 
   @staticmethod
-  def _GetKeySizeInBytes(signing_key):
-    modulus_file = common.MakeTempFile(prefix="modulus-")
-    cmd = ["openssl", "rsa", "-inform", "PEM", "-in", signing_key, "-modulus",
-           "-noout", "-out", modulus_file]
-    common.RunAndCheckOutput(cmd, verbose=False)
-
-    with open(modulus_file) as f:
-      modulus_string = f.read()
-    # The modulus string has the format "Modulus=$data", where $data is the
-    # concatenation of hex dump of the modulus.
-    MODULUS_PREFIX = "Modulus="
-    assert modulus_string.startswith(MODULUS_PREFIX)
-    modulus_string = modulus_string[len(MODULUS_PREFIX):]
-    key_size = len(modulus_string) // 2
-    assert key_size == 256 or key_size == 512, \
-        "Unsupported key size {}".format(key_size)
-    return key_size
+  def _GetMaximumSignatureSizeInBytes(signing_key):
+    out_signature_size_file = common.MakeTempFile("signature_size")
+    cmd = ["delta_generator", "--out_maximum_signature_size_file={}".format(
+        out_signature_size_file), "--private_key={}".format(signing_key)]
+    common.RunAndCheckOutput(cmd)
+    with open(out_signature_size_file) as f:
+      signature_size = f.read().rstrip()
+    logger.info("% outputs the maximum signature size: %", cmd[0],
+                signature_size)
+    return int(signature_size)
 
   def Sign(self, in_file):
     """Signs the given input file. Returns the output filename."""
@@ -396,7 +400,7 @@
     metadata_sig_file = common.MakeTempFile(prefix="sig-", suffix=".bin")
     cmd = ["brillo_update_payload", "hash",
            "--unsigned_payload", self.payload_file,
-           "--signature_size", str(payload_signer.key_size),
+           "--signature_size", str(payload_signer.maximum_signature_size),
            "--metadata_hash_file", metadata_sig_file,
            "--payload_hash_file", payload_sig_file]
     self._Run(cmd)
@@ -411,7 +415,7 @@
     cmd = ["brillo_update_payload", "sign",
            "--unsigned_payload", self.payload_file,
            "--payload", signed_payload_file,
-           "--signature_size", str(payload_signer.key_size),
+           "--signature_size", str(payload_signer.maximum_signature_size),
            "--metadata_signature_file", signed_metadata_sig_file,
            "--payload_signature_file", signed_payload_sig_file]
     self._Run(cmd)
@@ -2005,8 +2009,13 @@
       OPTIONS.payload_signer = a
     elif o == "--payload_signer_args":
       OPTIONS.payload_signer_args = shlex.split(a)
+    elif o == "--payload_signer_maximum_signature_size":
+      OPTIONS.payload_signer_maximum_signature_size = a
     elif o == "--payload_signer_key_size":
-      OPTIONS.payload_signer_key_size = a
+      # TODO(Xunchang) remove this option after cleaning up the callers.
+      logger.warning("The option '--payload_signer_key_size' is deprecated."
+                     " Use '--payload_signer_maximum_signature_size' instead.")
+      OPTIONS.payload_signer_maximum_signature_size = a
     elif o == "--extracted_input_target_files":
       OPTIONS.extracted_input = a
     elif o == "--skip_postinstall":
@@ -2047,6 +2056,7 @@
                                  "log_diff=",
                                  "payload_signer=",
                                  "payload_signer_args=",
+                                 "payload_signer_maximum_signature_size=",
                                  "payload_signer_key_size=",
                                  "extracted_input_target_files=",
                                  "skip_postinstall",
diff --git a/tools/releasetools/sign_target_files_apks.py b/tools/releasetools/sign_target_files_apks.py
index 0ef698e..0f4f1da 100755
--- a/tools/releasetools/sign_target_files_apks.py
+++ b/tools/releasetools/sign_target_files_apks.py
@@ -557,14 +557,13 @@
       OPTIONS.rebuild_recovery = True
 
     # Don't copy OTA certs if we're replacing them.
+    # Replacement of update-payload-key.pub.pem was removed in b/116660991.
     elif (
         OPTIONS.replace_ota_keys and
         filename in (
             "BOOT/RAMDISK/system/etc/security/otacerts.zip",
-            "BOOT/RAMDISK/system/etc/update_engine/update-payload-key.pub.pem",
             "RECOVERY/RAMDISK/system/etc/security/otacerts.zip",
-            "SYSTEM/etc/security/otacerts.zip",
-            "SYSTEM/etc/update_engine/update-payload-key.pub.pem")):
+            "SYSTEM/etc/security/otacerts.zip")):
       pass
 
     # Skip META/misc_info.txt since we will write back the new values later.
@@ -832,24 +831,6 @@
   # We DO NOT include the extra_recovery_keys (if any) here.
   WriteOtacerts(output_tf_zip, "SYSTEM/etc/security/otacerts.zip", mapped_keys)
 
-  # For A/B devices, update the payload verification key.
-  if misc_info.get("ab_update") == "true":
-    # Unlike otacerts.zip that may contain multiple keys, we can only specify
-    # ONE payload verification key.
-    if len(mapped_keys) > 1:
-      print("\n  WARNING: Found more than one OTA keys; Using the first one"
-            " as payload verification key.\n\n")
-
-    print("Using %s for payload verification." % (mapped_keys[0],))
-    pubkey = common.ExtractPublicKey(mapped_keys[0])
-    common.ZipWriteStr(
-        output_tf_zip,
-        "SYSTEM/etc/update_engine/update-payload-key.pub.pem",
-        pubkey)
-    common.ZipWriteStr(
-        output_tf_zip,
-        "BOOT/RAMDISK/system/etc/update_engine/update-payload-key.pub.pem",
-        pubkey)
 
 
 def ReplaceVerityPublicKey(output_zip, filename, key_path):
diff --git a/tools/releasetools/test_common.py b/tools/releasetools/test_common.py
index 59b05e9..8a52419 100644
--- a/tools/releasetools/test_common.py
+++ b/tools/releasetools/test_common.py
@@ -1373,6 +1373,39 @@
     self.assertEqual('5', chained_partition_args[1])
     self.assertTrue(os.path.exists(chained_partition_args[2]))
 
+  @test_utils.SkipIfExternalToolsUnavailable()
+  def test_AppendVBMetaArgsForPartition_recoveryAsChainedPartition_nonAb(self):
+    testdata_dir = test_utils.get_testdata_dir()
+    pubkey = os.path.join(testdata_dir, 'testkey.pubkey.pem')
+    info_dict = {
+        'avb_avbtool': 'avbtool',
+        'avb_recovery_key_path': pubkey,
+        'avb_recovery_rollback_index_location': 3,
+    }
+    cmd = common.GetAvbPartitionArg(
+        'recovery', '/path/to/recovery.img', info_dict)
+    self.assertFalse(cmd)
+
+  @test_utils.SkipIfExternalToolsUnavailable()
+  def test_AppendVBMetaArgsForPartition_recoveryAsChainedPartition_ab(self):
+    testdata_dir = test_utils.get_testdata_dir()
+    pubkey = os.path.join(testdata_dir, 'testkey.pubkey.pem')
+    info_dict = {
+        'ab_update': 'true',
+        'avb_avbtool': 'avbtool',
+        'avb_recovery_key_path': pubkey,
+        'avb_recovery_rollback_index_location': 3,
+    }
+    cmd = common.GetAvbPartitionArg(
+        'recovery', '/path/to/recovery.img', info_dict)
+    self.assertEqual(2, len(cmd))
+    self.assertEqual('--chain_partition', cmd[0])
+    chained_partition_args = cmd[1].split(':')
+    self.assertEqual(3, len(chained_partition_args))
+    self.assertEqual('recovery', chained_partition_args[0])
+    self.assertEqual('3', chained_partition_args[1])
+    self.assertTrue(os.path.exists(chained_partition_args[2]))
+
 
 class InstallRecoveryScriptFormatTest(test_utils.ReleaseToolsTestCase):
   """Checks the format of install-recovery.sh.
diff --git a/tools/releasetools/test_ota_from_target_files.py b/tools/releasetools/test_ota_from_target_files.py
index c3021a1..38faf64 100644
--- a/tools/releasetools/test_ota_from_target_files.py
+++ b/tools/releasetools/test_ota_from_target_files.py
@@ -885,10 +885,28 @@
       payload_offset, metadata_total = (
           property_files._GetPayloadMetadataOffsetAndSize(input_zip))
 
-    # Read in the metadata signature directly.
+    # The signature proto has the following format (details in
+    #  /platform/system/update_engine/update_metadata.proto):
+    #  message Signature {
+    #    optional uint32 version = 1;
+    #    optional bytes data = 2;
+    #    optional fixed32 unpadded_signature_size = 3;
+    #  }
+    #
+    # According to the protobuf encoding, the tail of the signature message will
+    # be [signature string(256 bytes) + encoding of the fixed32 number 256]. And
+    # 256 is encoded as 'x1d\x00\x01\x00\x00':
+    # [3 (field number) << 3 | 5 (type) + byte reverse of 0x100 (256)].
+    # Details in (https://developers.google.com/protocol-buffers/docs/encoding)
+    signature_tail_length = self.SIGNATURE_SIZE + 5
+    self.assertGreater(metadata_total, signature_tail_length)
     with open(output_file, 'rb') as verify_fp:
-      verify_fp.seek(payload_offset + metadata_total - self.SIGNATURE_SIZE)
-      metadata_signature = verify_fp.read(self.SIGNATURE_SIZE)
+      verify_fp.seek(payload_offset + metadata_total - signature_tail_length)
+      metadata_signature_proto_tail = verify_fp.read(signature_tail_length)
+
+    self.assertEqual(b'\x1d\x00\x01\x00\x00',
+                     metadata_signature_proto_tail[-5:])
+    metadata_signature = metadata_signature_proto_tail[:-5]
 
     # Now we extract the metadata hash via brillo_update_payload script, which
     # will serve as the oracle result.
@@ -1050,11 +1068,13 @@
     with open(file1, 'rb') as fp1, open(file2, 'rb') as fp2:
       self.assertEqual(fp1.read(), fp2.read())
 
+  @test_utils.SkipIfExternalToolsUnavailable()
   def test_init(self):
     payload_signer = PayloadSigner()
     self.assertEqual('openssl', payload_signer.signer)
-    self.assertEqual(256, payload_signer.key_size)
+    self.assertEqual(256, payload_signer.maximum_signature_size)
 
+  @test_utils.SkipIfExternalToolsUnavailable()
   def test_init_withPassword(self):
     common.OPTIONS.package_key = os.path.join(
         self.testdata_dir, 'testkey_with_passwd')
@@ -1067,18 +1087,27 @@
   def test_init_withExternalSigner(self):
     common.OPTIONS.payload_signer = 'abc'
     common.OPTIONS.payload_signer_args = ['arg1', 'arg2']
-    common.OPTIONS.payload_signer_key_size = '512'
+    common.OPTIONS.payload_signer_maximum_signature_size = '512'
     payload_signer = PayloadSigner()
     self.assertEqual('abc', payload_signer.signer)
     self.assertEqual(['arg1', 'arg2'], payload_signer.signer_args)
-    self.assertEqual(512, payload_signer.key_size)
+    self.assertEqual(512, payload_signer.maximum_signature_size)
 
-  def test_GetKeySizeInBytes_512Bytes(self):
+  @test_utils.SkipIfExternalToolsUnavailable()
+  def test_GetMaximumSignatureSizeInBytes_512Bytes(self):
     signing_key = os.path.join(self.testdata_dir, 'testkey_RSA4096.key')
     # pylint: disable=protected-access
-    key_size = PayloadSigner._GetKeySizeInBytes(signing_key)
-    self.assertEqual(512, key_size)
+    signature_size = PayloadSigner._GetMaximumSignatureSizeInBytes(signing_key)
+    self.assertEqual(512, signature_size)
 
+  @test_utils.SkipIfExternalToolsUnavailable()
+  def test_GetMaximumSignatureSizeInBytes_ECKey(self):
+    signing_key = os.path.join(self.testdata_dir, 'testkey_EC.key')
+    # pylint: disable=protected-access
+    signature_size = PayloadSigner._GetMaximumSignatureSizeInBytes(signing_key)
+    self.assertEqual(72, signature_size)
+
+  @test_utils.SkipIfExternalToolsUnavailable()
   def test_Sign(self):
     payload_signer = PayloadSigner()
     input_file = os.path.join(self.testdata_dir, self.SIGFILE)
diff --git a/tools/releasetools/testdata/testkey_EC.key b/tools/releasetools/testdata/testkey_EC.key
new file mode 100644
index 0000000..9e65a68
--- /dev/null
+++ b/tools/releasetools/testdata/testkey_EC.key
@@ -0,0 +1,5 @@
+-----BEGIN PRIVATE KEY-----
+MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQgGaguGj8Yb1KkqKHd
+ISblUsjtOCbzAuVpX81i02sm8FWhRANCAARBnuotwKOsuvjH6iwTDhOAi7Q5pLWz
+xDkZjg2pcfbfi9FFTvLYETas7B2W6fx9PUezUmHTFTDV2JZuMYYFdZOw
+-----END PRIVATE KEY-----
diff --git a/tools/warn.py b/tools/warn.py
index 5994124..6218f93 100755
--- a/tools/warn.py
+++ b/tools/warn.py
@@ -2264,7 +2264,7 @@
       i['compiled_patterns'].append(re.compile(pat))
 
 
-def find_android_root(path):
+def find_warn_py_and_android_root(path):
   """Set and return android_root path if it is found."""
   global android_root
   parts = path.split('/')
@@ -2273,8 +2273,36 @@
     # Android root directory should contain this script.
     if os.path.exists(root_path + '/build/make/tools/warn.py'):
       android_root = root_path
-      return root_path
-  return ''
+      return True
+  return False
+
+
+def find_android_root():
+  """Guess android_root from common prefix of file paths."""
+  # Use the longest common prefix of the absolute file paths
+  # of the first 10000 warning messages as the android_root.
+  global android_root
+  warning_lines = set()
+  warning_pattern = re.compile('^/[^ ]*/[^ ]*: warning: .*')
+  count = 0
+  infile = io.open(args.buildlog, mode='r', encoding='utf-8')
+  for line in infile:
+    if warning_pattern.match(line):
+      warning_lines.add(line)
+      count += 1
+      if count > 9999:
+        break
+      # Try to find warn.py and use its location to find
+      # the source tree root.
+      if count < 100:
+        path = os.path.normpath(re.sub(':.*$', '', line))
+        if find_warn_py_and_android_root(path):
+          return
+  # Do not use common prefix of a small number of paths.
+  if count > 10:
+    root_path = os.path.commonprefix(warning_lines)
+    if len(root_path) > 2 and root_path[len(root_path) - 1] == '/':
+      android_root = root_path[:-1]
 
 
 def remove_android_root_prefix(path):
@@ -2289,13 +2317,10 @@
   """Normalize file path relative to android_root."""
   # If path is not an absolute path, just normalize it.
   path = os.path.normpath(path)
-  if path[0] != '/':
-    return path
   # Remove known prefix of root path and normalize the suffix.
-  if android_root or find_android_root(path):
+  if path[0] == '/' and android_root:
     return remove_android_root_prefix(path)
-  else:
-    return path
+  return path
 
 
 def normalize_warning_line(line):
@@ -2670,6 +2695,7 @@
 
 
 def main():
+  find_android_root()
   # We must use 'utf-8' codec to parse some non-ASCII code in warnings.
   warning_lines = parse_input_file(
       io.open(args.buildlog, mode='r', encoding='utf-8'))