1 files changed, 171 insertions, 0 deletions
diff --git a/third_party/aom/build/cmake/util.cmake b/third_party/aom/build/cmake/util.cmake
new file mode 100644
index 0000000000..b70ec40137
--- /dev/null
+++ b/third_party/aom/build/cmake/util.cmake
@@ -0,0 +1,171 @@
+#
+# 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.
+#
+if(AOM_BUILD_CMAKE_UTIL_CMAKE_)
+  return()
+endif() # AOM_BUILD_CMAKE_UTIL_CMAKE_
+set(AOM_BUILD_CMAKE_UTIL_CMAKE_ 1)
+
+# Directory where generated sources will be written.
+set(AOM_GEN_SRC_DIR "${AOM_CONFIG_DIR}/gen_src")
+
+# Creates dummy source file in $AOM_CONFIG_DIR named $basename.$extension and
+# returns the full path to the dummy source file via the $out_file_path
+# parameter.
+macro(create_dummy_source_file basename extension out_file_path)
+  set(dummy_source_file "${AOM_GEN_SRC_DIR}/${basename}_dummy.${extension}")
+  file(
+    WRITE
+      "${dummy_source_file}" "// Generated file. DO NOT EDIT!\n"
+      "// ${target_name} needs a ${extension} file to force link language, \n"
+      "// or to silence a harmless CMake warning: Ignore me.\n"
+      "void ${target_name}_dummy_function(void) {}\n")
+endmacro()
+
+# Convenience function for adding a dummy source file to $target_name using
+# $extension as the file extension. Wraps create_dummy_source_file().
+function(add_dummy_source_file_to_target target_name extension)
+  create_dummy_source_file("${target_name}" "${extension}" "dummy_source_file")
+  target_sources(${target_name} PRIVATE ${dummy_source_file})
+endfunction()
+
+# Sets the value of the variable referenced by $feature to $value, and reports
+# the change to the user via call to message(WARNING ...). $cause is expected to
+# be a configuration variable that conflicts with $feature in some way. This
+# function is a noop if $feature is already set to $value.
+function(change_config_and_warn feature value cause)
+  if(${feature} EQUAL ${value})
+    return()
+  endif()
+  set(${feature} ${value} PARENT_SCOPE)
+  if(${value} EQUAL 1)
+    set(verb "Enabled")
+    set(reason "required for")
+  else()
+    set(verb "Disabled")
+    set(reason "incompatible with")
+  endif()
+  set(warning_message "${verb} ${feature}, ${reason} ${cause}.")
+  message(WARNING "--- ${warning_message}")
+endfunction()
+
+# Extracts the version string from $version_file and returns it to the user via
+# $version_string_out_var. To achieve this VERSION_STRING_NOSP is located in
+# $version_file and then everything but the string literal assigned to the
+# variable is removed. Quotes and the leading 'v' are stripped from the returned
+# string.
+function(extract_version_string version_file version_string_out_var)
+  file(STRINGS "${version_file}" aom_version REGEX "VERSION_STRING_NOSP")
+  string(REPLACE "#define VERSION_STRING_NOSP " "" aom_version "${aom_version}")
+  string(REPLACE "\"" "" aom_version "${aom_version}")
+  string(REPLACE " " "" aom_version "${aom_version}")
+  string(FIND "${aom_version}" "v" v_pos)
+  if(${v_pos} EQUAL 0)
+    string(SUBSTRING "${aom_version}" 1 -1 aom_version)
+  endif()
+  set("${version_string_out_var}" "${aom_version}" PARENT_SCOPE)
+endfunction()
+
+# Sets CMake compiler launcher to $launcher_name when $launcher_name is found in
+# $PATH. Warns user about ignoring build flag $launcher_flag when $launcher_name
+# is not found in $PATH.
+function(set_compiler_launcher launcher_flag launcher_name)
+  find_program(launcher_path "${launcher_name}")
+  if(launcher_path)
+    set(CMAKE_C_COMPILER_LAUNCHER "${launcher_path}" PARENT_SCOPE)
+    set(CMAKE_CXX_COMPILER_LAUNCHER "${launcher_path}" PARENT_SCOPE)
+    message("--- Using ${launcher_name} as compiler launcher.")
+  else()
+    message(WARNING
+              "--- Cannot find ${launcher_name}, ${launcher_flag} ignored.")
+  endif()
+endfunction()
+
+# Sentinel value used to detect when a variable has been set via the -D argument
+# passed to CMake on the command line.
+set(cmake_cmdline_helpstring "No help, variable specified on the command line.")
+
+# Wrapper macro for set() that does some book keeping to help with storage of
+# build configuration information.
+#
+# Sets the default value for variable $name when the value of $name has not
+# already been set via the CMake command line.
+#
+# The names of variables defaulted through this macro are added to
+# $AOM_CONFIG_VARS to facilitate build logging and diagnostics.
+macro(set_aom_detect_var name value type helpstring)
+  unset(list_index)
+  list(FIND AOM_DETECT_VARS ${name} list_index)
+  if(${list_index} EQUAL -1)
+    list(APPEND AOM_DETECT_VARS ${name})
+  endif()
+
+  # Update the variable only when it does not carry the CMake assigned help
+  # string for variables specified via the command line.
+  unset(cache_helpstring)
+  get_property(cache_helpstring CACHE ${name} PROPERTY HELPSTRING)
+  if(NOT "${cache_helpstring}" STREQUAL "${cmake_cmdline_helpstring}")
+    set(${name} ${value} CACHE ${type} "${helpstring}")
+    mark_as_advanced(${name})
+  else()
+    message(
+      WARNING
+        "${name} has been set by CMake, but it may be overridden by the build "
+        "system during environment detection")
+  endif()
+endmacro()
+
+# Wrapper macro for set() that does some book keeping to help with storage of
+# build configuration information.
+#
+# Sets the default value for variable $name when the value of $name has not
+# already been set via the CMake command line.
+#
+# The names of variables defaulted through this macro are added to
+# $AOM_CONFIG_VARS to facilitate build logging and diagnostics.
+macro(set_aom_config_var name value type helpstring)
+  unset(list_index)
+  list(FIND AOM_CONFIG_VARS ${name} list_index)
+  if(${list_index} EQUAL -1)
+    list(APPEND AOM_CONFIG_VARS ${name})
+  endif()
+
+  # Update the variable only when it does not carry the CMake assigned help
+  # string for variables specified via the command line.
+  unset(cache_helpstring)
+  get_property(cache_helpstring CACHE ${name} PROPERTY HELPSTRING)
+  if(NOT "${cache_helpstring}" STREQUAL "${cmake_cmdline_helpstring}")
+    set(${name} ${value} CACHE ${type} "${helpstring}")
+  endif()
+endmacro()
+
+# Wrapper macro for option() that does some book keeping to help with storage of
+# build configuration information.
+#
+# Sets the default value for variable $name when the value of $name has not
+# already been set via the CMake command line.
+#
+# The names of variables defaulted through this macro are added to
+# $AOM_OPTION_VARS to facilitate build logging and diagnostics.
+macro(set_aom_option_var name helpstring value)
+  unset(list_index)
+  list(FIND AOM_OPTION_VARS ${name} list_index)
+  if(${list_index} EQUAL -1)
+    list(APPEND AOM_OPTION_VARS ${name})
+  endif()
+
+  # Update the variable only when it does not carry the CMake assigned help
+  # string for variables specified via the command line.
+  unset(cache_helpstring)
+  get_property(cache_helpstring CACHE ${name} PROPERTY HELPSTRING)
+  if(NOT "${cache_helpstring}" STREQUAL "${cmake_cmdline_helpstring}")
+    option(${name} "${helpstring}" ${value})
+  endif()
+endmacro()