CubicSDR/docs/plans/modernize-cmake.md

Plan: Modernize CMake

See also: RECOMMENDATIONS.md | PLAN.md

Current State

• cmake_minimum_required(VERSION 2.8.12) — from 2013
• Uses -std=c++0x (draft C++11) instead of proper standard setting
• Global include_directories(), ADD_DEFINITIONS(), link_libraries() instead of target-specific
• Deprecated CMAKE_CREATE_WIN32_EXE, LINK_FLAGS, SOURCE_GROUP REGULAR_EXPRESSION
• Stray comma in CMAKE_OSX_DEPLOYMENT_TARGET assignment

Implementation Plan

Phase 1: Minimum viable modernization

1. Bump cmake_minimum_required(VERSION 3.14...3.28) — enables modern policies while allowing newer CMake.
2. Replace ADD_DEFINITIONS( -std=c++0x -pthread ) with:

   target_compile_features(CubicSDR PRIVATE cxx_std_14)
   find_package(Threads REQUIRED)
   target_link_libraries(CubicSDR PRIVATE Threads::Threads)
   

3. Fix the stray comma on the CMAKE_OSX_DEPLOYMENT_TARGET line: SET(CMAKE_OSX_DEPLOYMENT_TARGET, "10.9") → set(CMAKE_OSX_DEPLOYMENT_TARGET "10.9").
4. Replace set(CMAKE_CREATE_WIN32_EXE ...) with:

   set_target_properties(CubicSDR PROPERTIES WIN32_EXECUTABLE TRUE)
   target_link_options(CubicSDR PRIVATE /SUBSYSTEM:WINDOWS /ENTRY:"mainCRTStartup")
   

Phase 2: Target-specific commands

5. Replace all include_directories(...) with target_include_directories(CubicSDR PRIVATE ...).
6. Replace all ADD_DEFINITIONS(...) with target_compile_definitions(CubicSDR PRIVATE ...).
7. Replace link_libraries(${HAMLIB_LIBRARY}) with target_link_libraries(CubicSDR PRIVATE ${HAMLIB_LIBRARY}).
8. Replace set_target_properties(... LINK_FLAGS ...) with target_link_options().

Phase 3: Advanced modernization (optional, future)

9. Replace include(${wxWidgets_USE_FILE}) with imported targets (requires wxWidgets 3.2+).
10. Replace SOURCE_GROUP(... REGULAR_EXPRESSION ...) with source_group(TREE ...).
11. Consider bumping minimum to CMake 3.16+ for broader modern feature access.

Verification Criteria

• cmake_minimum_required version is 3.14 or higher.
• cmake -B build configures without errors on MSVC, GCC, and Clang.
• Build produces a working executable with no regressions.
• No global include_directories(), ADD_DEFINITIONS(), or link_libraries() remain (all are target-specific).
• The stray comma on the CMAKE_OSX_DEPLOYMENT_TARGET line is fixed.

Rollback Strategy

This is a high-touch change to a single file. If the build breaks:

1. git revert the commit to restore the original CMakeLists.txt.
2. The original CMake 2.8 patterns are functional on all platforms — the revert is safe.
3. If only Phase 2 causes issues (e.g., a missed include_directories), consider doing Phase 1 alone first and verifying before proceeding.

Files to Modify

File	Action
CMakeLists.txt	All phases