On Sunday 20 November 2022 21:36:19 LIU Hao wrote: > 在 2022-11-20 20:53, Pali Rohár 写道: > > Hello! I would like to propose a new parameter for gcc: -mcrtdll= to > > allow specifying against which Windows C Runtime library should be > > binary linked. On Windows there are more crt libraries and currently gcc > > links to libmsvcrt.a which is in most cases symlink to libmsvcrt-os.a > > (but can be changed, e.g. during mingw-w64 building). mingw-w64 project > > already builds import .a library for every crt dll library (from the old > > crtdll.dll up to the new ucrtbase.dll), so it is ready for usage. Simple > > patch for gcc which implements -mcrtdll parameter is below. Note that on > > internet are other very similar patches for -mcrtdll= parameters and > > some are parts of custom mingw32 / mingw-w64 gcc builds. What do you > > think? Could gcc have "official" support for -mcrtdll= parameter? > > > > > > It's not enough to just link against the desired library, you will also have > to define `__MSVCRT_VERSION__` accordingly (for UCRT it should be defined as > `0xE00` i.e. 14.0). > > The current status of such mechanism is that both the macro > `__MSVCRT_VERSION__` and the library 'libmsvcrt.a' are determined when > building mingw-w64, configurable by `--with-default-msvcrt=`, so they always > match. > > > [1] https://sourceforge.net/p/mingw-w64/mailman/message/36030072/
Thank you for explaining more details. My simple patch takes this in care and defines also __MSVCRT_VERSION__ to the correct value based on -mcrtdll parameter.
