I hope it is ok to CC Paul Eggert who applied the patch that broke
this as far as I understand.
Is the change below acceptable?
It is needed when building Octave targeting Windows. Without it, the
implementation of `casin` from the Windows runtime is used instead of the
replacement from MinGW-w64.
That means that results for the `casin` function are wrong without
that change.
Markus
Rebased on the current head of the master branch:
[PATCH] Keep "-lmingwex" and "-lmoldname" in linker flags for MinGW
* lib/autoconf/fortran.m4: Do not remove "-lmingwex" or "-lmoldname"
from the linker flags when targeting MinGW. Removing "-lmingwex" causes
an incorrect linker resolution for functions like "casin" for projects
that consist of Fortran and C++ sources. Removing "-lmoldname" causes
issues for Fortran projects that try to use POSIX-like C functions
without a `_` symbol prefix when targeting MinGW.
---
lib/autoconf/fortran.m4 | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/autoconf/fortran.m4 b/lib/autoconf/fortran.m4
index 75631492..0fc7545d 100644
--- a/lib/autoconf/fortran.m4
+++ b/lib/autoconf/fortran.m4
@@ -666,7 +666,7 @@ while test $[@%:@] != 1; do
-lang* | -lcrt*.o | -lc | -lgcc* | -lSystem | -libmil | -little \
|-LANG:=* | -LIST:* | -LNO:* | -link)
;;
- -lkernel32 | -lmingw* | -lmoldname)
+ -lkernel32)
# Ignore this library only on Windows-like systems.
case $host_os in
cygwin* | msys* | mingw* | windows*) ;;
--
2.44.0.windows.1
Am 12. Dezember 2024 um 13:42 schrieb "Markus Mützel":
> Stripping `-lmingwex` from the Fortran default linker flags can lead to
> a situation where the first `-lmsvcrt` appears before the first
> `-lmingwex` for a library that consists of Fortran and C++ sources.
> That means that the linker picks some functions from the Windows CRT that
> should instead be picked from `libmingwex.a`.
>
> It took quite some time to figure out an odd behavior when calling
> `std::asin` with a complex double precision value with a real part larger
> than 1.0 and an imaginary part of 0.0 in such a library.
> See also: https://octave.discourse.group/t/6026/75
>
> Also don't strip `-lmoldname` from these flags because omitting that
> library could result in issues when Fortran code tries to call POSIX-like
> C functions without a `_` prefix when targeting MinGW.
>
> The following change fixes these issues by essentially reverting the
> changes from:
> https://lists.gnu.org/r/autoconf-patches/2021-09/msg00000.html
>
> I'm not sure why `-lkernel32` needs to be removed from the linker flags
> when targeting MinGW. But we didn't observe an issue with that, so I left
> that as applied in that changeset.
>
> diff -urN autoconf-2.72/lib/autoconf/fortran.m4.orig
> autoconf-2.72/lib/autoconf/fortran.m4
> --- autoconf-2.72/lib/autoconf/fortran.m4.orig 2024-10-30
> 13:31:24.456674400 +0100
> +++ autoconf-2.72/lib/autoconf/fortran.m4 2024-12-11 16:08:46.415095400
> +0100
> @@ -705,7 +705,7 @@
> -lang* | -lcrt*.o | -lc | -lgcc* | -lSystem | -libmil | -little \
> |-LANG:=* | -LIST:* | -LNO:* | -link)
> ;;
> - -lkernel32 | -lmingw* | -lmoldname)
> + -lkernel32)
> # Ignore this library only on Windows-like systems.
> case $host_os in
> cygwin* | msys* | mingw* | windows*) ;;
>
