FindPython*: Add capability to control virtual env handling.

Fixes: #19097

5 files changed, 82 insertions, 0 deletions

diff --git a/Tests/FindPython/CMakeLists.txt b/Tests/FindPython/CMakeLists.txt
index 38211a4bb5..d6f50e7b10 100644
--- a/Tests/FindPython/CMakeLists.txt
+++ b/Tests/FindPython/CMakeLists.txt
@@ -68,6 +68,17 @@ if(CMake_TEST_FindPython)
     --build-options ${build_options}
     --test-command ${CMAKE_CTEST_COMMAND} -V -C $<CONFIGURATION>
     )
+
+  add_test(NAME FindPython.VirtualEnv COMMAND
+    ${CMAKE_CTEST_COMMAND} -C $<CONFIGURATION>
+    --build-and-test
+    "${CMake_SOURCE_DIR}/Tests/FindPython/VirtualEnv"
+    "${CMake_BINARY_DIR}/Tests/FindPython/VirtualEnv"
+    ${build_generator_args}
+    --build-project TestVirtualEnv
+    --build-options ${build_options}
+    --test-command ${CMAKE_CTEST_COMMAND} -V -C $<CONFIGURATION>
+    )
 endif()
 
 if(CMake_TEST_FindPython_NumPy)
diff --git a/Tests/FindPython/VirtualEnv/CMakeLists.txt b/Tests/FindPython/VirtualEnv/CMakeLists.txt
new file mode 100644
index 0000000000..64ba201861
--- /dev/null
+++ b/Tests/FindPython/VirtualEnv/CMakeLists.txt
@@ -0,0 +1,42 @@
+cmake_minimum_required(VERSION 3.1)
+
+project(TestVirtualEnv LANGUAGES NONE)
+
+include(CTest)
+
+find_package(Python3 REQUIRED COMPONENTS Interpreter)
+if (NOT Python3_FOUND)
+  message (FATAL_ERROR "Fail to found Python 3")
+endif()
+
+set (Python3_VIRTUAL_ENV "${CMAKE_CURRENT_BINARY_DIR}/py3venv")
+
+execute_process (COMMAND "${Python3_EXECUTABLE}" -m venv "${Python3_VIRTUAL_ENV}"
+                 RESULT_VARIABLE result
+                 OUTPUT_VARIABLE outputs
+                 ERROR_VARIABLE outputs)
+if (result)
+  message (FATAL_ERROR "Fail to create virtual environment: ${outputs}")
+endif()
+
+add_test(NAME FindPython3.VirtualEnvDefault
+         COMMAND "${CMAKE_COMMAND}" -E env --unset=PYTHONHOME
+                                           "VIRTUAL_ENV=${Python3_VIRTUAL_ENV}"
+                 "${CMAKE_COMMAND}" "-DPYTHON3_VIRTUAL_ENV=${Python3_VIRTUAL_ENV}"
+                 -P "${CMAKE_CURRENT_LIST_DIR}/VirtualEnvDefault.cmake")
+
+add_test(NAME FindPython3.VirtualEnvOnly
+         COMMAND "${CMAKE_COMMAND}" -E env --unset=PYTHONHOME
+                                           "VIRTUAL_ENV=${Python3_VIRTUAL_ENV}"
+                 "${CMAKE_COMMAND}" "-DPYTHON3_VIRTUAL_ENV=${Python3_VIRTUAL_ENV}"
+                 -P "${CMAKE_CURRENT_LIST_DIR}/VirtualEnvOnly.cmake")
+add_test(NAME FindPython3.UnsetVirtualEnvOnly
+         COMMAND "${CMAKE_COMMAND}" -E env --unset=PYTHONHOME
+                                           --unset=VIRTUAL_ENV
+                 "${CMAKE_COMMAND}" -P "${CMAKE_CURRENT_LIST_DIR}/VirtualEnvOnly.cmake")
+
+add_test(NAME FindPython3.VirtualEnvStandard
+         COMMAND "${CMAKE_COMMAND}" -E env --unset=PYTHONHOME
+                                           "VIRTUAL_ENV=${Python3_VIRTUAL_ENV}"
+                 "${CMAKE_COMMAND}" "-DPYTHON3_VIRTUAL_ENV=${Python3_VIRTUAL_ENV}"
+                 -P "${CMAKE_CURRENT_LIST_DIR}/VirtualEnvStandard.cmake")
diff --git a/Tests/FindPython/VirtualEnv/VirtualEnvDefault.cmake b/Tests/FindPython/VirtualEnv/VirtualEnvDefault.cmake
new file mode 100644
index 0000000000..020ecacd9d
--- /dev/null
+++ b/Tests/FindPython/VirtualEnv/VirtualEnvDefault.cmake
@@ -0,0 +1,6 @@
+
+find_package (Python3 REQUIRED)
+
+if (NOT Python3_EXECUTABLE MATCHES "^${PYTHON3_VIRTUAL_ENV}/.+")
+  message (FATAL_ERROR "Fail to use virtual environment")
+endif()
diff --git a/Tests/FindPython/VirtualEnv/VirtualEnvOnly.cmake b/Tests/FindPython/VirtualEnv/VirtualEnvOnly.cmake
new file mode 100644
index 0000000000..29a49249cb
--- /dev/null
+++ b/Tests/FindPython/VirtualEnv/VirtualEnvOnly.cmake
@@ -0,0 +1,16 @@
+
+#
+# Virtual environment is defined for python3
+# Trying to find a python2 using only virtual environment
+# It is expecting to fail if a virtual environment is active and to success otherwise.
+#
+set (Python2_FIND_VIRTUALENV ONLY)
+find_package (Python2 QUIET)
+
+if (PYTHON3_VIRTUAL_ENV AND Python2_FOUND)
+  message (FATAL_ERROR "Python2 unexpectedly found.")
+endif()
+
+if (NOT PYTHON3_VIRTUAL_ENV AND NOT Python2_FOUND)
+  message (FATAL_ERROR "Fail to find Python2.")
+endif()
diff --git a/Tests/FindPython/VirtualEnv/VirtualEnvStandard.cmake b/Tests/FindPython/VirtualEnv/VirtualEnvStandard.cmake
new file mode 100644
index 0000000000..89f27d8da2
--- /dev/null
+++ b/Tests/FindPython/VirtualEnv/VirtualEnvStandard.cmake
@@ -0,0 +1,7 @@
+
+set (Python3_FIND_VIRTUALENV STANDARD)
+find_package (Python3 REQUIRED)
+
+if (Python3_EXECUTABLE MATCHES "^${PYTHON3_VIRTUAL_ENV}/.+")
+  message (FATAL_ERROR "Python3 virtual env unexpectedly found.")
+endif()