Fix static linking when using MinGW-w64 #15167
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
HertzDevil
added
kind:bug
straight-shoota
approved these changes
Nov 6, 2024
straight-shoota
approved these changes
Nov 6, 2024
CTC97
pushed a commit
to CTC97/crystal
that referenced
this pull request
Nov 9, 2024
* The MinGW-w64 equivalent for MSVC's `libcmt.lib` or `msvcrt.lib` is provided by MinGW-w64's built-in spec files directly (see `cc -dumpspecs`), so we do not link against it. * There cannot be static libraries for the Win32 APIs in MinGW-w64, because that would be proprietary code; all static libraries on MSYS2 link against the C runtimes dynamically, i.e. they behave like `/MD` in MSVC or `CMAKE_MSVC_RUNTIME_LIBRARY=MultiThreadedDLL` in CMake. We therefore never link against `libucrt`. * Passing `-lucrt` explicitly may lead to a crash in the startup code when combined with `-static` and `-msvcrt`, depending on the relative link order. In MinGW-w64, [`-lmsvcrt` is already equivalent to `-lucrt` or `-lmsvcrt-os`](https://gcc.gnu.org/onlinedocs/gcc/Cygwin-and-MinGW-Options.html), depending on how it was built; in particular, `/ucrt64/bin/libmsvcrt.a` is a copy of `libucrt.a` in MSYS2, but `/mingw64/bin/libmsvcrt.a` is a copy of `libmsvcrt-os.a`. Thus we drop `-lucrt` entirely and rely on the MinGW-w64's build-time configuration to select the appropriate C runtime. * `-mcrtdll` can be used to override the C runtime, and it _should_ be possible to cross-build binaries between the MINGW64 and the UCRT64 environments using this flag. The interpreter now imitates this linker behavior.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Resolves part of #6170.
libcmt.libormsvcrt.libis provided by MinGW-w64's built-in spec files directly (seecc -dumpspecs), so we do not link against it./MDin MSVC orCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreadedDLLin CMake. We therefore never link againstlibucrt.-lucrtexplicitly may lead to a crash in the startup code when combined with-staticand-msvcrt, depending on the relative link order. In MinGW-w64,-lmsvcrtis already equivalent to-lucrtor-lmsvcrt-os, depending on how it was built; in particular,/ucrt64/bin/libmsvcrt.ais a copy oflibucrt.ain MSYS2, but/mingw64/bin/libmsvcrt.ais a copy oflibmsvcrt-os.a. Thus we drop-lucrtentirely and rely on the MinGW-w64's build-time configuration to select the appropriate C runtime.-mcrtdllcan be used to override the C runtime, and it should be possible to cross-build binaries between the MINGW64 and the UCRT64 environments using this flag. The interpreter now imitates this linker behavior.