From c4d962006ddb910927a805cc318b89635379d4b4 Mon Sep 17 00:00:00 2001
From: =?utf8?q?=EB=B0=95=EC=84=B8=ED=9D=AC/=EB=8F=99=EC=9E=91=EC=A0=9C?=
 =?utf8?q?=EC=96=B4Lab=28SR=29/Principal=20Engineer/=EC=82=BC=EC=84=B1?=
 =?utf8?q?=EC=A0=84=EC=9E=90?= <saehie.park@samsung.com>
Date: Thu, 10 May 2018 08:24:41 +0900
Subject: [PATCH] Add gflags download and build (#210)

* Add gflags download and build

This will add download and build gflags within cmake
- default action is off
- system installed version can be used when download is off

Signed-off-by: SaeHie Park <saehie.park@samsung.com>

* apply comments

* move compile line

* use interface and move build options settings
---
 CMakeLists.txt                          |  1 +
 cmake/packages/GFlagsConfig.cmake       | 33 +++++++++++++++++++++++++++++++++
 cmake/packages/GFlagsSourceConfig.cmake | 18 ++++++++++++++++++
 3 files changed, 52 insertions(+)
 create mode 100644 cmake/packages/GFlagsConfig.cmake
 create mode 100644 cmake/packages/GFlagsSourceConfig.cmake

diff --git a/CMakeLists.txt b/CMakeLists.txt
index fbc463d..62f9ac9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -17,6 +17,7 @@ option(DOWNLOAD_EIGEN "Download Eigen source" OFF)
 option(DOWNLOAD_FARMHASH "Download farmhash source" OFF)
 option(DOWNLOAD_GEMMLOWP "Download GEMM low precesion library source" OFF)
 option(DOWNLOAD_NEON2SSE "Download NEON2SSE library source" OFF)
+option(DOWNLOAD_GFLAGS "Download GFlags source" OFF)
 option(DOWNLOAD_FLATBUFFERS "Download FlatBuffers source" OFF)
 option(DOWNLOAD_TENSORFLOW "Download TensorFlow source" OFF)
 option(DOWNLOAD_CAFFE "Download Caffe source" OFF)
diff --git a/cmake/packages/GFlagsConfig.cmake b/cmake/packages/GFlagsConfig.cmake
new file mode 100644
index 0000000..f93c784
--- /dev/null
+++ b/cmake/packages/GFlagsConfig.cmake
@@ -0,0 +1,33 @@
+function(_GFlags_import)
+  if(TARGET gflags)
+    set(GFlags_FOUND True PARENT_SCOPE)
+    return()
+  endif()
+
+  nncc_find_package(GFlagsSource QUIET)
+
+  if(GFlagsSource_FOUND)
+    # build static multi-thread library
+    set(GFLAGS_BUILD_STATIC_LIB On)
+    set(GFLAGS_BUILD_gflags_LIB On)
+    set(GFLAGS_BUILD_gflags_nothreads_LIB Off)
+    add_subdirectory(${GFLAGS_SOURCE_DIR} external/gflags)
+  else(GFlagsSource_FOUND)
+    set(GFLAGS_ROOT_DIR "" CACHE PATH "Folder contains GFlags")
+    find_path(GFLAGS_INCLUDE_DIR gflags/gflags.h PATHS ${GFLAGS_ROOT_DIR})
+    find_library(GFLAGS_LIBRARY gflags)
+
+    if(NOT GFLAGS_INCLUDE_DIR)
+      set(GFlags_FOUND False PARENT_SCOPE)
+      return()
+    endif(NOT GFLAGS_INCLUDE_DIR)
+
+    add_library(gflags INTERFACE)
+    target_include_directories(gflags INTERFACE ${GFLAGS_INCLUDE_DIR})
+    target_link_libraries(gflags INTERFACE ${GFLAGS_LIBRARY})
+  endif(GFlagsSource_FOUND)
+
+  set(GFlags_FOUND True PARENT_SCOPE)
+endfunction(_GFlags_import)
+
+_GFlags_import()
diff --git a/cmake/packages/GFlagsSourceConfig.cmake b/cmake/packages/GFlagsSourceConfig.cmake
new file mode 100644
index 0000000..89d230d
--- /dev/null
+++ b/cmake/packages/GFlagsSourceConfig.cmake
@@ -0,0 +1,18 @@
+function(_GFlagsSource_import)
+  if(NOT DOWNLOAD_GFLAGS)
+    set(GFlagsSource_FOUND False PARENT_SCOPE)
+    return()
+  endif(NOT DOWNLOAD_GFLAGS)
+
+  nncc_find_package(ExternalSourceTools REQUIRED)
+  nncc_find_package(OptionTools REQUIRED)
+
+  envoption(GFLAGS_URL https://github.com/gflags/gflags/archive/v2.2.1.tar.gz)
+
+  ExternalSource_Download(GFLAGS ${GFLAGS_URL})
+
+  set(GFLAGS_SOURCE_DIR ${GFLAGS_SOURCE_DIR} PARENT_SCOPE)
+  set(GFlagsSource_FOUND True PARENT_SCOPE)
+endfunction(_GFlagsSource_import)
+
+_GFlagsSource_import()
-- 
2.7.4