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CMake: re-add /RTC1 removal fix
Add msvcHack.cmake to consolidate funky business Move the runtime library fix into the same location The RTC fix was present in 4.3 and below, it somehow got lost in a rebase perhaps.
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‎cmake/msvcHack.cmake

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#[=======================================================================[.rst:
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msvcHack.cmake
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--------------
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There are a couple of things that CMake does which mess up the build and are
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hard to work around. This cmake script is an attempt to document and work
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around those shortcomings.
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MSVC Runtime Selection
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----------------------
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There are two main ways to set the msvc runtime library;
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Using ``target_compile_options()`` to add the flags
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or using the ``CMAKE_MSVC_RUNTIME_LIBRARY`` property_ abstraction, introduced
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in CMake version 3.15 with the policy CMP0091_ to remove the flags from
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``CMAKE_<LANG>_FLAGS_<CONFIG>``.
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Default: ``CMAKE_MSVC_RUNTIME_LIBRARY="MultiThreaded$<$<CONFIG:Debug>:Debug>DLL"``
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This initializes each target's ``MSVC_RUNTIME_LIBRARY`` property at the time of
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target creation.
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it is stated in the msvc_ documentation that: "All modules passed to a given
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invocation of the linker must have been compiled with the same runtime library
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compiler option (/MD, /MT, /LD)."
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This creates a conundrum for us, the ``CMAKE_MSVC_RUNTIME_LIBRARY`` needs to be
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correct at the time the target is created, but we have no control over the
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consumers CMake scripts, and the per-target ``MSVC_RUNTIME_LIBRARY`` property
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is not transient.
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It has been raised that not using ``CMAKE_MSVC_RUNTIME_LIBRARY`` can also cause
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issues_ when a dependency( independent to godot-cpp ) that doesn't set any
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runtime flags, which relies purely on the ``CMAKE_MSVC_RUNTIME_LIBRARY``
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variable will very likely not have the correct msvc runtime flags set.
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So we'll set ``CMAKE_MSVC_RUNTIME_LIBRARY`` as CACHE STRING so that it will be
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available for consumer target definitions, but also be able to be overridden if
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needed.
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Additionally we message consumers notifying them and pointing to this
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documentation.
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.. _CMP0091:https://cmake.org/cmake/help/latest/policy/CMP0091.html
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.. _property:https://cmake.org/cmake/help/latest/variable/CMAKE_MSVC_RUNTIME_LIBRARY.html
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.. https://discourse.cmake.org/t/mt-staticrelease-doesnt-match-value-md-dynamicrelease/5428/4
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.. _msvc: https://learn.microsoft.com/en-us/cpp/build/reference/md-mt-ld-use-run-time-library
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.. _issues: https://github.com/godotengine/godot-cpp/issues/1699
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Run-Time Error Checks
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---------------------
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The MSVC compiler flag_ /RTC[] is Used to enable and disable the run-time error
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checks feature, in conjunction with the runtime_checks pragma.
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.. _flag: https://learn.microsoft.com/en-us/cpp/build/reference/rtc-run-time-error-checks?view=msvc-170
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If enabled it triggers a stacktrace when a template_debug godot loads an
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gdextension. Unfortunately CMake adds this flag to Debug builds, and there
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is no simple solution for removing it. The solution here, is drawn from
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others experiences 1_, 2_.
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.. _1: https://discourse.cmake.org/t/how-do-i-remove-compile-options-from-target/5965
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.. _2: https://stackoverflow.com/questions/74426638/how-to-remove-rtc1-from-specific-target-or-file-in-cmake
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There are two locations where the RTC options appear, and they are both within
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the same macro in the file_: Platform/Windows-MSVC.cmake
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.. _file: https://gitlab.kitware.com/cmake/cmake/-/blob/566e96d42db35e2c88ceb5d0f3de49736295c496/Modules/Platform/Windows-MSVC.cmake
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FUTURE: CMake introduced the ``CMAKE_MSVC_RUNTIME_CHECKS`` option_ in v4.0
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.. _option: https://cmake.org/cmake/help/latest/variable/CMAKE_MSVC_RUNTIME_CHECKS.html
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]=======================================================================]
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if(MSVC)
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message(
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STATUS
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"NOTE: We know its bad etiquette to set global build variables, however,\n"
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"\tCMAKE_MSVC_RUNTIME_LIBRARY needs to be set to something specific for godot-cpp, and\n"
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"\tCMAKE_CXX_FLAGS_DEBUG needs /RTC1 removed as it triggers a segfaut on when template_debug loads\n"
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"\tPlease ensure that any targets that are linking with godot-cpp are defined after godot-cpp\n"
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"\tFor more information please read godot-cpp/cmake/msvcHack.cmake"
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)
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if(CMAKE_VS_PLATFORM_TOOLSET MATCHES "v[0-9]+_clang_.*") # The same condition that Windows-MSVC.cmake uses
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else()
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string(REPLACE "/RTC1" "" CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG}")
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string(REPLACE "/RTC1" "" CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG}")
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endif()
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set(CMAKE_MSVC_RUNTIME_LIBRARY
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"MultiThreaded$<IF:$<BOOL:${GODOTCPP_DEBUG_CRT}>,DebugDLL,$<$<NOT:$<BOOL:${GODOTCPP_USE_STATIC_CPP}>>:DLL>>"
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CACHE STRING
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"Select the MSVC runtime library for use by compilers targeting the MSVC ABI."
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)
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endif()

‎cmake/windows.cmake

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@@ -10,50 +10,11 @@ project directive, it means that
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* ``CMAKE_CURRENT_SOURCE_DIR`` is the location of godot-cpp's CMakeLists.txt
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* ``CMAKE_SOURCE_DIR`` is the location where any prior ``project(...)``
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directive was
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MSVC Runtime Selection
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----------------------
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There are two main ways to set the msvc runtime library;
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Using ``target_compile_options()`` to add the flags
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or using the ``CMAKE_MSVC_RUNTIME_LIBRARY`` property_ abstraction, introduced
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in CMake version 3.15 with the policy CMP0091_ to remove the flags from
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``CMAKE_<LANG>_FLAGS_<CONFIG>``.
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Default: ``CMAKE_MSVC_RUNTIME_LIBRARY="MultiThreaded$<$<CONFIG:Debug>:Debug>DLL"``
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This initializes each target's ``MSVC_RUNTIME_LIBRARY`` property at the time of
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target creation.
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it is stated in the msvc_ documentation that: "All modules passed to a given
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invocation of the linker must have been compiled with the same runtime library
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compiler option (/MD, /MT, /LD)."
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This creates a conundrum for us, the ``CMAKE_MSVC_RUNTIME_LIBRARY`` needs to be
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correct at the time the target is created, but we have no control over the
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consumers CMake scripts, and the per-target ``MSVC_RUNTIME_LIBRARY`` property
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is not transient.
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It has been raised that not using ``CMAKE_MSVC_RUNTIME_LIBRARY`` can also cause
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issues_ when a dependency( independent to godot-cpp ) that doesn't set any
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runtime flags, which relies purely on the ``CMAKE_MSVC_RUNTIME_LIBRARY``
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variable will very likely not have the correct msvc runtime flags set.
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So we'll set ``CMAKE_MSVC_RUNTIME_LIBRARY`` as CACHE STRING so that it will be
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available for consumer target definitions, but also be able to be overridden if
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needed.
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Additionally we message consumers notifying them and pointing to this
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documentation.
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.. _CMP0091:https://cmake.org/cmake/help/latest/policy/CMP0091.html
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.. _property:https://cmake.org/cmake/help/latest/variable/CMAKE_MSVC_RUNTIME_LIBRARY.html
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.. https://discourse.cmake.org/t/mt-staticrelease-doesnt-match-value-md-dynamicrelease/5428/4
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.. _msvc: https://learn.microsoft.com/en-us/cpp/build/reference/md-mt-ld-use-run-time-library
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.. _issues: https://github.com/godotengine/godot-cpp/issues/1699
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]=======================================================================]
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# MSVC compiler requires some changes to the defaults CMake sets up
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set(CMAKE_PROJECT_godot-cpp_INCLUDE cmake/msvcHack.cmake)
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#[============================[ Windows Options ]============================]
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function(windows_options)
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#[[ Options from SCons
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option(GODOTCPP_USE_STATIC_CPP "Link MinGW/MSVC C++ runtime libraries statically" ON)
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option(GODOTCPP_DEBUG_CRT "Compile with MSVC's debug CRT (/MDd)" OFF)
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message(
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STATUS
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"If not already cached, setting CMAKE_MSVC_RUNTIME_LIBRARY.\n"
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"\tFor more information please read godot-cpp/cmake/windows.cmake"
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)
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set(CMAKE_MSVC_RUNTIME_LIBRARY
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"MultiThreaded$<IF:$<BOOL:${GODOTCPP_DEBUG_CRT}>,DebugDLL,$<$<NOT:$<BOOL:${GODOTCPP_USE_STATIC_CPP}>>:DLL>>"
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CACHE STRING
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"Select the MSVC runtime library for use by compilers targeting the MSVC ABI."
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)
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endfunction()
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#[===========================[ Target Generation ]===========================]

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