Failed to build with musl libc in WSL 1

[CyanoHao]

In short, with the unexpected floating point control word, the macro NET_SSLEAY_PERL_VERSION is evaluated to a floating point number in Makefile.PL, causing a C preprocessor error.

Build log: build.log
Userland: Gentoo profile default/linux/amd64/23.0/musl
Kernel: 4.4.0-19041-Microsoft (WSL 1, Windows 10 21H2 19044.5371)
Musl version: 1.2.5
GCC version: 14.2.1_p20241221 p7
Perl version: 5.40.0
SSLeay version: 1.940.0

Extra info

1. Test command: echo 'print $] * 1e6' | perl

   • Musl + WSL 1: 5040000.00000088
   • Glibc or Linux kernel: 5040000

   Investigating into Perl interpreter, I found there's nothing strange about multiply operation, but $] has unexpected value.

2. Test command: echo 'printf("%.16f\n", $])' | perl

   • Musl + WSL 1: 5.0400000000008732
   • Glibc or Linux kernel: 5.0400000000000000

   It seems the version number has been broken when compiling Perl interpreter.

3. Test program:

   #include <stdio.h>
   int main()
   {
     const char *s = "5.040000";
     double v;
     sscanf(s, "%lf", &v);
     printf("%.16f\n", v);
   }

   • Musl + WSL 1: 5.0400000000008732
   • Glibc or Linux kernel: 5.0400000000000000

[h-vn]

Would you be able to update Makefile.PL as shown below and let us know if this fixes the problem. The updated version tries to avoid multiplication by creating a string of the version first and then updating the string by dropping the dot . from the version. The end result should be the same while the method differs. If it works, I'll clean it up and add it.

Another option could be to do the match and truncate the string to include just the required number of digits.

diff --git a/Makefile.PL b/Makefile.PL
index deb75f1..523086f 100644
--- a/Makefile.PL
+++ b/Makefile.PL
@@ -116,7 +116,9 @@ $eumm_args{DEFINE} = '';
 # Expose the current Perl version to the C preprocessor. This is used in
 # SSLeay.xs before perl.h is included (and therefore before its PERL_VERSION_*
 # macros are available).
-add_define( $eumm_args{DEFINE}, "-DNET_SSLEAY_PERL_VERSION=" . $] * 1e6 );
+my $perlver = "$]";
+$perlver =~ s/\.//s;
+add_define( $eumm_args{DEFINE}, "-DNET_SSLEAY_PERL_VERSION=$perlver");
 
 # Suppress deprecation warnings during compilation.
 # https://www.openssl.org/docs/manmaster/man7/openssl_user_macros.html