From bbdd74ce9a4b4cc28da93a0ff99830ae8f9796b1 Mon Sep 17 00:00:00 2001
From: Axel Isouard <axel@isouard.fr>
Date: Sun, 19 Mar 2017 10:17:26 +0100
Subject: [PATCH] Add libwebrtc_execute function, use it in DepotTools.cmake

---
 CMakeModules/DepotTools.cmake       | 18 +++++-----
 CMakeModules/LibWebRTCExecute.cmake | 51 +++++++++++++++++++++++++++++
 2 files changed, 61 insertions(+), 8 deletions(-)
 create mode 100644 CMakeModules/LibWebRTCExecute.cmake

diff --git a/CMakeModules/DepotTools.cmake b/CMakeModules/DepotTools.cmake
index 94a60d0..7ecb5d3 100644
--- a/CMakeModules/DepotTools.cmake
+++ b/CMakeModules/DepotTools.cmake
@@ -2,15 +2,17 @@ if (HAS_OWN_DEPOT_TOOLS)
   return()
 endif (HAS_OWN_DEPOT_TOOLS)
 
-if (WEBRTC_REVISION)
-  message(STATUS "Retrieving date for commit ${WEBRTC_REVISION}")
-  execute_process(COMMAND ${GIT_EXECUTABLE} log -1 --format=%ci ${WEBRTC_REVISION}
-                  WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
-                  OUTPUT_VARIABLE _WEBRTC_COMMIT_DATE)
+include(LibWebRTCExecute)
 
-  if (NOT _WEBRTC_COMMIT_DATE)
-    message(FATAL_ERROR "-- Unable to find webrtc commit date at ${WEBRTC_REVISION}")
-  endif (NOT _WEBRTC_COMMIT_DATE)
+if (WEBRTC_REVISION)
+  libwebrtc_execute(
+      COMMAND ${GIT_EXECUTABLE} log -1 --format=%ci ${WEBRTC_REVISION}
+      OUTPUT_VARIABLE _WEBRTC_COMMIT_DATE
+      WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+      STAMPFILE webrtc-commit-date
+      STATUS "Retrieving date for commit ${WEBRTC_REVISION}"
+      ERROR "Unable to find webrtc commit date at ${WEBRTC_REVISION}"
+  )
 elseif (WEBRTC_BRANCH_HEAD)
   message(STATUS "Retrieving branch-heads refspecs")
   execute_process(COMMAND ${GIT_EXECUTABLE} config remote.origin.fetch +refs/branch-heads/*:refs/remotes/branch-heads/* ^\\+refs/branch-heads/\\*:.*$
diff --git a/CMakeModules/LibWebRTCExecute.cmake b/CMakeModules/LibWebRTCExecute.cmake
new file mode 100644
index 0000000..e5c93f7
--- /dev/null
+++ b/CMakeModules/LibWebRTCExecute.cmake
@@ -0,0 +1,51 @@
+if (LIBWEBRTC_EXECUTE_INCLUDED)
+  return()
+endif (LIBWEBRTC_EXECUTE_INCLUDED)
+set(LIBWEBRTC_EXECUTE_INCLUDED true)
+
+include(CMakeParseArguments)
+include(Environment)
+
+function (libwebrtc_execute)
+  set(ONE_VALUE_ARGS OUTPUT_VARIABLE WORKING_DIRECTORY STAMPFILE STATUS ERROR)
+  set(MULTI_VALUE_ARGS COMMAND)
+  cmake_parse_arguments(COMMAND "" "${ONE_VALUE_ARGS}" "${MULTI_VALUE_ARGS}" ${ARGN})
+
+  set(CMF_DIR ${CMAKE_BINARY_DIR}/CMakeFiles)
+
+  if (COMMAND_STAMPFILE)
+    set(STAMP_FILE "${CMF_DIR}/${COMMAND_STAMPFILE}")
+
+    if (EXISTS ${STAMP_FILE})
+      if (COMMAND_OUTPUT_VARIABLE)
+        file(READ ${STAMP_FILE} _OUTPUT)
+
+        if (_OUTPUT)
+          set(${COMMAND_OUTPUT_VARIABLE} ${_OUTPUT} PARENT_SCOPE)
+        endif (_OUTPUT)
+      endif (COMMAND_OUTPUT_VARIABLE)
+
+      return()
+    endif (EXISTS ${STAMP_FILE})
+  endif (COMMAND_STAMPFILE)
+
+  if (COMMAND_STATUS)
+    message(STATUS ${COMMAND_STATUS})
+  endif (COMMAND_STATUS)
+
+  execute_process(COMMAND ${COMMAND_COMMAND}
+                  WORKING_DIRECTORY ${COMMAND_WORKING_DIRECTORY}
+                  OUTPUT_VARIABLE _OUTPUT)
+
+  if (NOT _OUTPUT)
+    message(FATAL_ERROR "-- " ${COMMAND_ERROR})
+  endif (NOT _OUTPUT)
+
+  if (COMMAND_STAMP_FILE)
+    file(WRITE ${STAMP_FILE} ${_OUTPUT})
+  endif (COMMAND_STAMP_FILE)
+
+  if (COMMAND_OUTPUT_VARIABLE)
+    set(${COMMAND_OUTPUT_VARIABLE} ${_OUTPUT} PARENT_SCOPE)
+  endif (COMMAND_OUTPUT_VARIABLE)
+endfunction ()