[lldb] Bump the required SWIG version to 3

[JDevlieghere]

Summary

Bump the required SWIG version to 3. If my memory serves me well we last bumped the required SWIG version to 2 for Python 3. At that time SWIG 3 had already been around for a while so everyone I know was already using that.

It appears that SWIG 3 is the only version that officially supports C++11 which we're using in the typemap. SWIG 3 was released in 2014 so I think it's reasonable to make that the minimally supported version.

https://bugs.llvm.org/show_bug.cgi?id=48685

[teemperor]

LGTM modulo the warning messages still referencing 2 instead of 3.

lldb/cmake/modules/FindLuaAndSwig.cmake

20

SWIG 3

lldb/cmake/modules/FindPythonAndSwig.cmake

45

"SWIG 3 or later ..." as pointed out in the bug report.

lldb/cmake/modules/FindLuaAndSwig.cmake

 #.rst:
 # FindLuaAndSwig
 # --------------
 #
 # Find Lua and SWIG as a whole.
 
 if(LUA_LIBRARIES AND LUA_INCLUDE_DIR AND SWIG_EXECUTABLE)
   set(LUAANDSWIG_FOUND TRUE)
 else()
-  find_package(SWIG 2.0)
+  find_package(SWIG 3.0)
   if (SWIG_FOUND)
     find_package(Lua 5.3)
     if(LUA_FOUND AND SWIG_FOUND)
       mark_as_advanced(
         LUA_LIBRARIES
         LUA_INCLUDE_DIR
         SWIG_EXECUTABLE)
     endif()
   else()
-    message(STATUS "SWIG 2 or later is required for Lua support in LLDB but could not be found")
+    message(STATUS "SWIG 3 or later is required for Lua support in LLDB but could not be found")
   endif()
 
   include(FindPackageHandleStandardArgs)
   find_package_handle_standard_args(LuaAndSwig
                                     FOUND_VAR
                                       LUAANDSWIG_FOUND
                                     REQUIRED_VARS
                                       LUA_LIBRARIES
                                       LUA_INCLUDE_DIR
                                       SWIG_EXECUTABLE)
 endif()

lldb/cmake/modules/FindPythonAndSwig.cmake

mark_as_advanced(
       Python3_RPATH
       SWIG_EXECUTABLE)
   endif()
 endmacro()
 
 if(Python3_LIBRARIES AND Python3_INCLUDE_DIRS AND Python3_EXECUTABLE AND SWIG_EXECUTABLE)
   set(PYTHONANDSWIG_FOUND TRUE)
 else()
-  find_package(SWIG 2.0)
+  find_package(SWIG 3.0)
   if (SWIG_FOUND)
       FindPython3()
   else()
-    message(STATUS "SWIG 2 or later is required for Python support in LLDB but could not be found")
+    message(STATUS "SWIG 3 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

lldb/docs/resources/build.rst

 
 * `CMake <https://cmake.org>`_
 * `Ninja <https://ninja-build.org>`_ (strongly recommended)
 
 If you want to run the test suite, you'll need to build LLDB with Python
 scripting support.
 
 * `Python <http://www.python.org/>`_
-* `SWIG <http://swig.org/>`_ 2 or later.
+* `SWIG <http://swig.org/>`_ 3 or later.
 
 Optional Dependencies
 *********************
 
 Although the following dependencies are optional, they have a big impact on
 LLDB's functionality. It is strongly encouraged to build LLDB with these
 dependencies enabled.