[lldb/CMake] Autodetect Python dependency

Python was the last remaining "optional" dependency for LLDB. This moves
the code to find Python into FindPythonInterpAndLibs using the same
principles as FindCursesAndPanel.

Differential revision: https://reviews.llvm.org/D72107

1 files changed, 51 insertions, 0 deletions

diff --git a/lldb/cmake/modules/FindPythonInterpAndLibs.cmake b/lldb/cmake/modules/FindPythonInterpAndLibs.cmake
new file mode 100644
index 00000000000..fcbf0212d72
--- /dev/null
+++ b/lldb/cmake/modules/FindPythonInterpAndLibs.cmake
@@ -0,0 +1,51 @@
+#.rst:
+# FindPythonInterpAndLibs
+# -----------
+#
+# Find the python interpreter and libraries as a whole.
+
+if(PYTHON_LIBRARIES AND PYTHON_INCLUDE_DIRS AND PYTHON_EXECUTABLE)
+  set(PYTHONINTERPANDLIBS_FOUND TRUE)
+else()
+  if ("${CMAKE_SYSTEM_NAME}" STREQUAL "Windows")
+    find_package(Python3 COMPONENTS Interpreter Development QUIET)
+    if (Python3_FOUND AND Python3_Interpreter_FOUND)
+      set(PYTHON_LIBRARIES ${Python3_LIBRARIES})
+      set(PYTHON_INCLUDE_DIRS ${Python3_INCLUDE_DIRS})
+      set(PYTHON_EXECUTABLE ${Python3_EXECUTABLE})
+      mark_as_advanced(
+        PYTHON_LIBRARIES
+        PYTHON_INCLUDE_DIRS
+        PYTHON_EXECUTABLE)
+    endif()
+  else()
+    find_package(PythonInterp QUIET)
+    find_package(PythonLibs QUIET)
+    if(PYTHONINTERP_FOUND AND PYTHONLIBS_FOUND)
+      if (NOT CMAKE_CROSSCOMPILING)
+        string(REPLACE "." ";" pythonlibs_version_list ${PYTHONLIBS_VERSION_STRING})
+        list(GET pythonlibs_version_list 0 pythonlibs_major)
+        list(GET pythonlibs_version_list 1 pythonlibs_minor)
+
+        # Ignore the patch version. Some versions of macOS report a different
+        # patch version for the system provided interpreter and libraries.
+        if (CMAKE_CROSSCOMPILING OR (PYTHON_VERSION_MAJOR VERSION_EQUAL pythonlibs_major AND
+            PYTHON_VERSION_MINOR VERSION_EQUAL pythonlibs_minor))
+          mark_as_advanced(
+            PYTHON_LIBRARIES
+            PYTHON_INCLUDE_DIRS
+            PYTHON_EXECUTABLE)
+        endif()
+      endif()
+    endif()
+  endif()
+
+  include(FindPackageHandleStandardArgs)
+  find_package_handle_standard_args(PythonInterpAndLibs
+                                    FOUND_VAR
+                                      PYTHONINTERPANDLIBS_FOUND
+                                    REQUIRED_VARS
+                                      PYTHON_LIBRARIES
+                                      PYTHON_INCLUDE_DIRS
+                                      PYTHON_EXECUTABLE)
+endif()