Update aom to commit id e87fb2378f01103d5d6e477a4ef6892dc714e614

third_party/aom/build/cmake/version.cmake

@@ -0,0 +1,55 @@
+##
+## Copyright (c) 2017, Alliance for Open Media. All rights reserved
+##
+## This source code is subject to the terms of the BSD 2 Clause License and
+## the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+## was not distributed with this source code in the LICENSE file, you can
+## obtain it at www.aomedia.org/license/software. If the Alliance for Open
+## Media Patent License 1.0 was not distributed with this source code in the
+## PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+##
+cmake_minimum_required(VERSION 3.5)
+
+set(REQUIRED_ARGS
+    "AOM_ROOT" "AOM_CONFIG_DIR" "GIT_EXECUTABLE" "PERL_EXECUTABLE")
+
+foreach (arg ${REQUIRED_ARGS})
+  if ("${${arg}}" STREQUAL "")
+    message(FATAL_ERROR "${arg} must not be empty.")
+  endif ()
+endforeach ()
+
+include("${AOM_ROOT}/build/cmake/util.cmake")
+
+# Generate the version string for this run.
+unset(aom_version)
+if (EXISTS "${GIT_EXECUTABLE}")
+  execute_process(COMMAND ${GIT_EXECUTABLE} --git-dir=${AOM_ROOT}/.git describe
+                  OUTPUT_VARIABLE aom_version ERROR_QUIET)
+  string(STRIP "${aom_version}" aom_version)
+
+  # Remove the leading 'v' from the version string.
+  string(FIND "${aom_version}" "v" v_pos)
+  if (${v_pos} EQUAL 0)
+    string(SUBSTRING "${aom_version}" 1 -1 aom_version)
+  endif ()
+endif ()
+
+if ("${aom_version}" STREQUAL "")
+  set(aom_version "${AOM_ROOT}/CHANGELOG")
+endif ()
+
+unset(last_aom_version)
+if (EXISTS "${AOM_CONFIG_DIR}/aom_version.h")
+  extract_version_string("${AOM_CONFIG_DIR}/aom_version.h" last_aom_version)
+endif ()
+
+if (NOT "${aom_version}" STREQUAL "${last_aom_version}")
+  # TODO(tomfinegan): Perl dependency is unnecessary. CMake can do everything
+  # that is done by version.pl on its own (if a bit more verbose...).
+  execute_process(
+    COMMAND ${PERL_EXECUTABLE} "${AOM_ROOT}/build/cmake/version.pl"
+    --version_data=${aom_version}
+    --version_filename=${AOM_CONFIG_DIR}/aom_version.h
+    VERBATIM)
+endif ()