From 30d68924fc58533f8a8a12e281efdc691d638cb9 Mon Sep 17 00:00:00 2001
From: a-maurice <amaurice@google.com>
Date: Tue, 29 Nov 2022 16:47:47 -0800
Subject: [PATCH] Use find_program to get python in cmake (#546)

* Use find_program to get python in cmake

* Update build_linux.yml

* Revert "Update build_linux.yml"

This reverts commit 82bd9f41dc62a79931e4424d5846d46d67eb1117.
---
 CMakeLists.txt            | 6 ++++++
 cmake/build_aar.cmake     | 2 +-
 cmake/firebase_swig.cmake | 6 +++---
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0536f1fc..ac052bed 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -146,6 +146,12 @@ else()
   set(DESKTOP OFF)
 endif()
 
+# Define the Python executable before including the subprojects
+find_program(FIREBASE_PYTHON_EXECUTABLE
+  NAMES python3 python
+  REQUIRED
+)
+
 include(FindPkgConfig)
 include(android_dependencies)
 include(build_universal)
diff --git a/cmake/build_aar.cmake b/cmake/build_aar.cmake
index 6f06ca98..2cf20853 100644
--- a/cmake/build_aar.cmake
+++ b/cmake/build_aar.cmake
@@ -45,7 +45,7 @@ function(build_aar LIBRARY_NAME LIBRARY_TARGET PROGUARD_TARGET
 
   add_custom_command(
     OUTPUT "${OUTPUT_AAR}"
-    COMMAND python "${FIREBASE_SOURCE_DIR}/aar_builder/build_aar.py"
+    COMMAND ${FIREBASE_PYTHON_EXECUTABLE} "${FIREBASE_SOURCE_DIR}/aar_builder/build_aar.py"
       "--output_file=${OUTPUT_AAR}"
       "--library_file=$<TARGET_FILE:${LIBRARY_TARGET}>"
       "--architecture=${ANDROID_ABI}"
diff --git a/cmake/firebase_swig.cmake b/cmake/firebase_swig.cmake
index 3556bfaf..db69bc9e 100644
--- a/cmake/firebase_swig.cmake
+++ b/cmake/firebase_swig.cmake
@@ -202,13 +202,13 @@ macro(firebase_swig_add_library name)
     OUTPUT ${UNITY_SWIG_CS_FIX_FILE}
     DEPENDS ${UNITY_SWIG_CS_GEN_FILE}
     COMMAND
-      python
+      ${FIREBASE_PYTHON_EXECUTABLE}
         ${CMAKE_CURRENT_LIST_DIR}/../swig_commenter.py
         --input=\"${all_cpp_header_files}\"
         --output=\"${UNITY_SWIG_CS_GEN_FILE}\"
         --namespace_prefix=\"Firebase\"
     COMMAND
-      python
+      ${FIREBASE_PYTHON_EXECUTABLE}
         ${FIREBASE_SWIG_FIX_PY}
         --language=csharp
         --in_file=\"${UNITY_SWIG_CS_GEN_FILE}\"
@@ -233,7 +233,7 @@ macro(firebase_swig_add_library name)
     OUTPUT ${UNITY_SWIG_CPP_FIX_FILE}
     DEPENDS ${UNITY_SWIG_CPP_GEN_FILE}
     COMMAND
-      python
+      ${FIREBASE_PYTHON_EXECUTABLE}
         ${FIREBASE_SWIG_FIX_PY}
         --language=cpp
         --in_file=\"${UNITY_SWIG_CPP_GEN_FILE}\"