From 698eccf15e9a7d17ea8c86673da1fbabdade315a Mon Sep 17 00:00:00 2001
From: Guoyu Wang <62914304+gwang-msft@users.noreply.github.com>
Date: Fri, 11 Sep 2020 16:10:36 -0700
Subject: [PATCH] Add iOS build instruction (#5125)

* ios build instruction

* fix logger issue in onnx_model_info

* Revert "fix logger issue in onnx_model_info"

This reverts commit 72f2b88256ccf29c75fefbcd1daf6b4dcf7e0c61.

* Address comments and fix small issue in iOS build
---
 BUILD.md             | 35 +++++++++++++++++++++++++++++++++++
 cmake/CMakeLists.txt |  8 +++++++-
 2 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/BUILD.md b/BUILD.md
index df099a8533..edd2118ba8 100644
--- a/BUILD.md
+++ b/BUILD.md
@@ -32,6 +32,7 @@
     * [x86](#x86)
     * [ARM](#ARM)
     * [Android](#Android)
+    * [iOS](#iOS)
 
 **[Training](#Training)**
 
@@ -1036,6 +1037,40 @@ Android NNAPI Execution Provider can be built using building commands in [Androi
 
 ---
 
+### iOS
+
+#### Prerequisites
+* A Mac computer with latest macOS
+* Xcode, https://developer.apple.com/xcode/
+* CMake, https://cmake.org/download/
+* Python 3, https://www.python.org/downloads/mac-osx/
+
+#### General Info:
+* iOS Platforms
+
+   The following two platforms are supported
+   * iOS device (iPhone, iPad) with arm64 architecture
+   * iOS simulator with x86_64 architecture
+
+   armv7, armv7s and i386 architectures are not currently supported.
+* apple_deploy_target
+
+   Specify the minimum version of the target platform (iOS) on which the target binaries are to be deployed.
+
+#### Build Instructions
+Run one of the following build scripts from the ONNX Runtime repository root,
+##### Cross build for iOS device
+```
+/build.sh --config <Release|Debug|RelWithDebInfo|MinSizeRel> --use_xcode \
+           --ios --ios_sysroot iphoneos --osx_arch arm64 --apple_deploy_target 12
+```
+##### Cross build for iOS simulator
+```
+/build.sh --config <Release|Debug|RelWithDebInfo|MinSizeRel> --use_xcode \
+           --ios --ios_sysroot iphonesimulator --osx_arch x86_64 --apple_deploy_target 12
+```
+---
+
 ### AMD MIGraphX
 
 See more information on the MIGraphX Execution Provider [here](./docs/execution_providers/MIGraphX-ExecutionProvider.md).
diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index 316362ade4..97f3ceca02 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -14,7 +14,13 @@ endif()
 # Support OS X versions 10.12+
 # This variable is ignored on non-Apple platforms and needs to be set prior to the first project(...) invocation
 # TODO: Make the miniumum deployment target MacOSX version configurable
-set(CMAKE_OSX_DEPLOYMENT_TARGET "10.12" CACHE STRING "Minimum OS X deployment version for ORT" FORCE)
+# If the CMAKE_OSX_DEPLOYMENT_TARGET was set (currently valid only for iOS build),
+# we will cache its value instead of the default "10.12"
+if (NOT DEFINED CMAKE_OSX_DEPLOYMENT_TARGET)
+  set(CMAKE_OSX_DEPLOYMENT_TARGET "10.12" CACHE STRING "Minimum OS X deployment version for ORT" FORCE)
+else()
+  set(CMAKE_OSX_DEPLOYMENT_TARGET ${CMAKE_OSX_DEPLOYMENT_TARGET} CACHE STRING "Minimum OS X deployment version for ORT" FORCE)
+endif()
 
 # Project
 project(onnxruntime C CXX)