[lldb] Add a cmake warning about the python/swig incompatibility

Raise awareness of the fact that some versions of swig and python (and build types) just don't mix. One day this will be a reason to require swig>=4.0, but this version is too hot off the press right now.. Differential Revision: https://reviews.llvm.org/D88967
YuriPlyakhin · Oct 8, 2020 · d4a7c70 · d4a7c70
1 parent 4424d24
commit d4a7c70
Showing 1 changed file with 11 additions and 0 deletions.
diff --git a/lldb/cmake/modules/FindPythonAndSwig.cmake b/lldb/cmake/modules/FindPythonAndSwig.cmake
@@ -45,6 +45,17 @@ else()
     message(STATUS "SWIG 2 or later is required for Python support in LLDB but could not be found")
   endif()
 
+  get_property(MULTI_CONFIG GLOBAL PROPERTY GENERATOR_IS_MULTI_CONFIG)
+  if ("${Python3_VERSION}" VERSION_GREATER_EQUAL "3.7" AND
+      "${SWIG_VERSION}" VERSION_LESS "4.0" AND WIN32 AND (
+      ${MULTI_CONFIG} OR (${uppercase_CMAKE_BUILD_TYPE} STREQUAL "DEBUG")))
+    # Technically this can happen with non-Windows builds too, but we are not
+    # able to detect whether Python was built with assertions, and only Windows
+    # has the requirement that Debug LLDB must use Debug Python.
+    message(WARNING "Debug builds of LLDB are likely to be unusable due to "
+      "<https://github.com/swig/swig/issues/1321>. Please use SWIG >= 4.0.")
+  endif()
+
   include(FindPackageHandleStandardArgs)
   find_package_handle_standard_args(PythonAndSwig
                                     FOUND_VAR