MinGW UCRT target
Summary
This proposal is to add the UCRT target & support from Fedora to the MinGW cross-toolchains.
Owner
- Name: Marc-André Lureau
- Email: marcandre.lureau@redhat.com
Current status
- Targeted release: Fedora Linux 37
- Last updated: 2022-02-16
- devel thread
- FESCo issue: #2754
- Tracker bug: <will be assigned by the Wrangler>
- Release notes tracker: <will be assigned by the Wrangler>
Detailed Description
The current mingw32 and mingw64 cross-toolchains provided by Fedora target the MSVCRT (Microsoft Visual C++ Runtime). Since Visual Studio 15 & Windows 10, the default and recommended runtime is UCRT. See also MSVCRT vs UCRT.
A new toolchain target triple x86_64-w64-mingw32ucrt and associated binaries will be added.
Fedora MinGW macros will be provided to target UCRT, with ucrt64-* prefix (ex: ucrt64-meson)
mingw-* libraries will be progressively adjusted to add the produced ucrt64-* binaries.
Since mingw-*.spec are very repetitive and cumbersome to modify (each mingw32, mingw64, ucrt package has to be defined manually, and this is tedious and error-prone), a custom MinGW/Fedora tool or solution will be proposed. In the meantime, packages can be modified to add manually the new target.
UCRT plans on mingw@lists.fedoraproject.org
Feedback
Benefit to Fedora
This change will allow to cross-compile projects to Windows with the up to date C runtime & headers, and better c99 support. This should allow to more easily mix binaries produced from different versions or compilers as well.
Scope
- Proposal owners:
- update the mingw filesystem, binutils, headers, gcc & winpthreads packages
- bootstrap the new toolchain
- propose a solution to simplify library packaging with the different targets
- update some common library packages, such as mingw-zlib
- Other developers:
- Progressively adjust the mingw-* packages to produce ucrt64- packages, following the updated guidelines.
- Release engineering: #Releng issue number
- Policies and guidelines: N/A (not needed for this Change)
https://fedoraproject.org/wiki/Packaging:MinGW packaging guideline will be adjusted.
- Trademark approval: N/A (not needed for this Change)
- Alignment with Objectives:
Upgrade/compatibility impact
None
How To Test
$ x86_64-w64-mingw32ucrt-gcc test.c
$ /usr/bin/mingw-objdump -p a.exe | grep DLL
vma: Hint Time Forward DLL First
DLL Name: KERNEL32.dll
DLL Name: api-ms-win-crt-time-l1-1-0.dll
DLL Name: api-ms-win-crt-math-l1-1-0.dll
DLL Name: api-ms-win-crt-runtime-l1-1-0.dll
DLL Name: api-ms-win-crt-environment-l1-1-0.dll
DLL Name: api-ms-win-crt-private-l1-1-0.dll
DLL Name: api-ms-win-crt-heap-l1-1-0.dll
DLL Name: api-ms-win-crt-locale-l1-1-0.dll
DLL Name: api-ms-win-crt-stdio-l1-1-0.dll
DLL Name: api-ms-win-crt-string-l1-1-0.dll
User Experience
Windows binaries produced by Fedora cross-toolchain will target a more modern and compatible C runtime, bringing hopefully better compatibility & safety.
Dependencies
None
Contingency Plan
- Contingency mechanism: N/A (not a System Wide Change)
- Contingency deadline: N/A (not a System Wide Change)
- Blocks release? No (not a System Wide Change)
Documentation
N/A (not a System Wide Change)
Release Notes
The new MinGW toolchain and tools are available to compile binaries targeting the Windows UCRT.