add ios build script

engine/Scripts/lib_build_ios.sh

+work_path=$(pwd)
+engine_path=
+platform=
+gn_params=""
+optimize="--unoptimized"
+ninja_params=""
+runtime_mode=
+bitcode=""
+output_path=
+
+echo "setting environment variable and other params..."
+
+while getopts ":r:p:m:eo" opt
+do
+    case $opt in
+        r)
+        engine_path=$OPTARG # set engine_path, depot_tools and flutter engine folder will be put into this path
+        ;;
+        p)
+        gn_params="$gn_params --$OPTARG" # set the target platform android/ios/linux
+        ;;
+        m)
+        runtime_mode=$OPTARG
+        gn_params="$gn_params --runtime-mode=$runtime_mode" # set runtime mode release/debug/profile
+        ;;
+        e)
+        bitcode="-bitcode_bundle -bitcode_verify"
+        gn_params="$gn_params --bitcode" # enable-bitcode switch
+        ;;
+        o)
+        optimize="" # optimize code switch
+        ;;
+        ?)
+        echo "unknown param"
+        exit 1;;
+    esac
+done
+
+if [ "$runtime_mode" == "release" ] && [ "$optimize" == "--unoptimized" ];
+then
+  output_path="ios_release_unopt"
+  ninja_params=" -C out/$output_path flutter/third_party/txt:txt_lib"
+elif [ "$runtime_mode" == "release" ] && [ "$optimize" == "" ];
+then
+  output_path="ios_release"
+  ninja_params="-C out/$output_path flutter/third_party/txt:txt_lib"
+elif [ "$runtime_mode" == "debug" ] && [ "$optimize" == "--unoptimized" ];
+then
+  output_path="ios_debug_unopt"
+  ninja_params=" -C out/$output_path flutter/third_party/txt:txt_lib"
+elif [ "$runtime_mode" == "debug" ] && [ "$optimize" == "" ];
+then
+output_path="ios_debug"
+  ninja_params=" -C out/$output_path flutter/third_party/txt:txt_lib"
+elif [ "$runtime_mode" == "profile" ];
+then
+  echo "not support profile build yet"
+  exit 1
+fi
+
+gn_params="$gn_params $optimize"
+
+#set environment variable
+function isexist()
+{
+    source_str=$1
+    test_str=$2
+    
+    strings=$(echo $source_str | sed 's/:/ /g')
+    for str in $strings
+    do  
+        if [ $test_str = $str ]; then
+            return 0
+        fi  
+    done
+    return 1
+}
+
+if [ ! $FLUTTER_ROOT_PATH ];then
+  echo "export FLUTTER_ROOT_PATH=$engine_path/engine/src" >> ~/.bash_profile
+else
+  echo "This environment variable has been set, skip"
+fi
+
+if isexist $PATH $engine_path/depot_tools; then 
+  echo "This environment variable has been set, skip"
+else 
+  echo "export PATH=$engine_path/depot_tools:\$PATH" >> ~/.bash_profile
+fi
+source ~/.bash_profile
+
+echo "\nGetting Depot Tools..." 
+if [ ! -n "$engine_path" ]; then   
+  echo "Flutter engine path is not exist, please set the path by using \"-r\" param to set a engine path."  
+  exit 1
+fi
+cd $engine_path	
+if [ -d 'depot_tools' ] && [ -d "depot_tools/.git" ];
+then
+  echo "depot_tools already installed, skip"
+else
+  git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git
+  gclient
+fi
+
+echo "\nGetting flutter engine..."
+
+if [ -d 'engine' ];
+then
+  echo "engine folder already exist, skip"
+else
+  mkdir engine
+fi
+cd engine
+#git@github.com:guanghuispark/engine.git is a temp repo, replace it later
+echo "solutions = [
+  {
+    \"managed\": False,
+    \"name\": \"src/flutter\",
+    \"url\": \"git@github.com:guanghuispark/engine.git\", 
+    \"custom_deps\": {},
+    \"deps_file\": \"DEPS\",
+    \"safesync_url\": \"\",
+  },
+]" > .gclient
+
+gclient sync
+
+cd src/flutter
+git checkout flutter-1.17-candidate.5
+gclient sync -D
+
+echo "\nSCompiling engine..."
+#apply patch to Build.gn
+cd third_party/txt
+cp -f $work_path/patches/BUILD.gn.patch BUILD.gn.patch
+patch < BUILD.gn.patch -N
+
+cd $engine_path/engine/src/build/mac
+cp -f $work_path/patches/find_sdk.patch find_sdk.patch
+patch < find_sdk.patch -N
+cd ../..
+./flutter/tools/gn $gn_params
+
+
+echo "icu_use_data_file=false" >> out/$output_path/args.gn
+ninja $ninja_params
+
+echo "\nStarting build engine..."
+cd $work_path
+cd ..
+
+if [ "$runtime_mode" == "release" ];
+then
+  mono bee.exe ios_release
+elif [ "$runtime_mode" == "debug" ];
+then
+  mono bee.exe ios_debug
+fi
+
+echo "\nStarting prlink library..."
+cd Scripts
+xcode_path=""
+xcode_path=`python -c 'import prelink; print prelink.get_xcode_path()'`
+
+target_files=""
+tundra_file="$work_path/../artifacts/tundra.dag.json"
+cd ..
+python3 Scripts/prelink.py $tundra_file $runtime_mode $output_path $work_path $bitcode
+

engine/Scripts/prelink.py

+# coding=utf-8
+import os
+import sys
+import json
+
+def get_xcode_path():
+    res = os.popen('xcode-select -p')
+    return res.read()
+
+def get_target_files(tundra_file, runtime_mode):
+    if not os.path.exists(tundra_file):
+        print('tundra.dag.json file not found')
+        return null
+    with open(tundra_file, 'r') as f:
+        temp = json.loads(f.read())
+        json_list = temp['Nodes']
+        target_files=''
+        for item in json_list:
+            if item['Annotation'].startswith('Lib_iOS_arm64') and item['Annotation'].find("release_iOS_arm64") != -1:
+                action = item['Action']
+                o_file_list = action.split("\"")
+                for o in o_file_list:
+                    if o.endswith('.o'):
+                        target_files += ' '+o
+        return target_files
+    
+def prelinkfiles(tundra_file, runtime_mode, output_path, work_path, bitcode):
+    target_files = get_target_files(tundra_file, runtime_mode)
+    if not target_files:
+        print("get prelink xxx.o files failed")
+    else:
+        flutter_root_path = os.environ['FLUTTER_ROOT_PATH']
+        os.system('nm -j ' + flutter_root_path + '/out/' + output_path + '/obj/flutter/third_party/txt/libtxt_lib.a > third.symbol')
+        xcode_path = get_xcode_path().strip()
+        os.system('\"' + xcode_path + '/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld" -r -arch arm64 ' + bitcode + ' -syslibroot ' + xcode_path + '/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk -unexported_symbols_list third.symbol ' + target_files + ' ' + flutter_root_path + '/out/' + output_path + '/obj/flutter/third_party/txt/libtxt_lib.a -o "libUIWidgets.o"')
+        os.system('\"' + xcode_path + '/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool" -arch_only arm64 -static "libUIWidgets.o" -o "libUIWidgets.a"')
+        os.system('\"' + xcode_path + '/Toolchains/XcodeDefault.xctoolchain/usr/bin/strip" -x "libUIWidgets.a"')
+        os.system('cp -r libUIWidgets.a ' + '../com.unity.uiwidgets/Runtime/Plugins/'+ output_path + '/libUIWidgets.a')
+
+if __name__ == "__main__":
+    if len(sys.argv) > 5:
+        prelinkfiles(sys.argv[1], sys.argv[2], sys.argv[3], sys.argv[4], sys.argv[5])
+    else:
+        prelinkfiles(sys.argv[1], sys.argv[2], sys.argv[3], sys.argv[4], "")