From 1133315746eb3661abf1fdf7853ce4dd9e201387 Mon Sep 17 00:00:00 2001
From: Robert Nishihara <robertnishihara@gmail.com>
Date: Mon, 11 Jul 2016 12:16:10 -0700
Subject: [PATCH] help cmake find right python interpreter on mac (#251)

---
 CMakeLists.txt                | 22 ++++++++++++----------
 cmake/Modules/FindNumPy.cmake |  6 +++---
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 20ccd7733..c5921f72d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -8,15 +8,17 @@ list(APPEND CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake/Modules)
 
 set(CMAKE_PREFIX_PATH "${CMAKE_SOURCE_DIR}/thirdparty/grpc/bins/opt/" ${CMAKE_PREFIX_PATH})
 
-find_package(PythonInterp REQUIRED)
-
 if(NOT APPLE)
+    find_package(PythonInterp REQUIRED)
     find_package(PythonLibs REQUIRED)
-else(NOT APPLE)
-    execute_process(COMMAND ${PYTHON_EXECUTABLE} -c
-                    "import sys; skip = 2 if sys.platform.startswith('win') else 1; print 'python' + sys.version[0:3:skip]"
+    set(CUSTOM_PYTHON_EXECUTABLE ${PYTHON_EXECUTABLE})
+else()
+    find_program(CUSTOM_PYTHON_EXECUTABLE python)
+    message("-- Found Python program: ${CUSTOM_PYTHON_EXECUTABLE}")
+    execute_process(COMMAND ${CUSTOM_PYTHON_EXECUTABLE} -c
+                    "import sys; print 'python' + sys.version[0:3]"
                     OUTPUT_VARIABLE PYTHON_LIBRARY_NAME OUTPUT_STRIP_TRAILING_WHITESPACE)
-    execute_process(COMMAND ${PYTHON_EXECUTABLE} -c
+    execute_process(COMMAND ${CUSTOM_PYTHON_EXECUTABLE} -c
                     "import sys; print sys.exec_prefix"
                     OUTPUT_VARIABLE PYTHON_PREFIX OUTPUT_STRIP_TRAILING_WHITESPACE)
     FIND_LIBRARY(PYTHON_LIBRARIES
@@ -24,18 +26,18 @@ else(NOT APPLE)
                  HINTS "${PYTHON_PREFIX}"
                  PATH_SUFFIXES "lib" "libs"
                  NO_DEFAULT_PATH)
-    execute_process(COMMAND ${PYTHON_EXECUTABLE} -c
+    execute_process(COMMAND ${CUSTOM_PYTHON_EXECUTABLE} -c
                     "from distutils.sysconfig import *; print get_python_inc()"
                     OUTPUT_VARIABLE PYTHON_INCLUDE_DIRS OUTPUT_STRIP_TRAILING_WHITESPACE)
     if(PYTHON_LIBRARIES AND PYTHON_INCLUDE_DIRS)
         SET(PYTHONLIBS_FOUND TRUE)
         message("-- Found PythonLibs: " ${PYTHON_LIBRARIES})
         message("-- -- Used custom search path")
-    else(PYTHON_LIBRARIES AND PYTHON_INCLUDE_DIRS)
+    else()
         find_package(PythonLibs REQUIRED)
         message("-- -- Used find_package(PythonLibs)")
-    endif(PYTHON_LIBRARIES AND PYTHON_INCLUDE_DIRS)
-endif(NOT APPLE)
+    endif()
+endif()
 
 find_package(NumPy REQUIRED)
 find_package(Boost REQUIRED)
diff --git a/cmake/Modules/FindNumPy.cmake b/cmake/Modules/FindNumPy.cmake
index 6e1f3c415..0b9fb3e5c 100644
--- a/cmake/Modules/FindNumPy.cmake
+++ b/cmake/Modules/FindNumPy.cmake
@@ -14,8 +14,8 @@
 unset(NUMPY_VERSION)
 unset(NUMPY_INCLUDE_DIR)
 
-if(PYTHONINTERP_FOUND)
-  execute_process(COMMAND "${PYTHON_EXECUTABLE}" "-c"
+if(NOT "${CUSTOM_PYTHON_EXECUTABLE}" STREQUAL "CUSTOM_PYTHON_EXECUTABLE-NOTFOUND")
+  execute_process(COMMAND "${CUSTOM_PYTHON_EXECUTABLE}" "-c"
     "import numpy as n; print(n.__version__); print(n.get_include());"
     RESULT_VARIABLE __result
     OUTPUT_VARIABLE __output
@@ -42,7 +42,7 @@ if(PYTHONINTERP_FOUND)
     endif()
   endif()
 else()
-  message(STATUS "To find NumPy Python interpretator is required to be found.")
+  message(STATUS "To find NumPy Python executable is required to be found.")
 endif()
 
 include(FindPackageHandleStandardArgs)