Re: meson vs windows perl

meson.build has this code

    ldopts = run_command(perl, '-MExtUtils::Embed', '-e', 'ldopts', check: true).stdout().strip()
    undesired = run_command(perl_conf_cmd, 'ccdlflags', check: true).stdout().split()
    undesired += run_command(perl_conf_cmd, 'ldflags', check: true).stdout().split()

    perl_ldopts = []
    foreach ldopt : ldopts.split(' ')
      if ldopt == '' or ldopt in undesired
        continue
      endif

      perl_ldopts += ldopt.strip('"')
    endforeach

    message('LDFLAGS recommended by perl: "@0@"'.format(ldopts))
    message('LDFLAGS for embedding perl: "@0@"'.format(' '.join(perl_ldopts)))

This code is seriously broken if perl reports items including spaces, when a) removing the quotes is quite wrong, and b) splitting on spaces is also wrong.

Here's an example from one of my colleagues:

C:\Program Files\Microsoft Visual Studio\2022\Professional>perl.EXE -MExtUtils::Embed -e ldopts  -nologo -nodefaultlib -debug -opt:ref,icf -ltcg  -libpath:"C:\edb\languagepack\v4\Perl-5.38\lib\CORE" 
-machine:AMD64 -subsystem:console,"5.02"  "C:\edb\languagepack\v4\Perl-5.38\lib\CORE\perl538.lib" 
"C:\Program Files\Microsoft Visual Studio\2022\Professional\VC\Tools\MSVC\14.38.33130\lib\x64\oldnames.lib" 
"C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64\kernel32.lib" 
"C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64\user32.lib" 
"C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64\gdi32.lib" 
"C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64\winspool.lib" 
"C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64\comdlg32.lib" 
"C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64\advapi32.lib" 
"C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64\shell32.lib" 
"C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64\ole32.lib" 
"C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64\oleaut32.lib" 
"C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64\netapi32.lib" 
"C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64\uuid.lib" 
"C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64\ws2_32.lib" 
"C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64\mpr.lib" 
"C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64\winmm.lib" 
"C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64\version.lib" 
"C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64\odbc32.lib" 
"C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64\odbccp32.lib" 
"C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64\comctl32.lib" 
"C:\Program Files\Microsoft Visual Studio\2022\Professional\VC\Tools\MSVC\14.38.33130\lib\x64\msvcrt.lib" 
"C:\Program Files\Microsoft Visual Studio\2022\Professional\VC\Tools\MSVC\14.38.33130\lib\x64\vcruntime.lib" 
"C:\Program Files (x86)\Windows Kits\10\lib\10.0.22621.0\ucrt\x64\ucrt.lib"

And with that we get errors like

cl : Command line warning D9024 : unrecognized source file type 'C:\Program', object file assumed
cl : Command line warning D9024 : unrecognized source file type 'Files\Microsoft', object file assumed
cl : Command line warning D9024 : unrecognized source file type 'Visual', object file assumed
cl : Command line warning D9024 : unrecognized source file type 'C:\Program', object file assumed
cl : Command line warning D9024 : unrecognized source file type 'Files', object file assumed
cl : Command line warning D9024 : unrecognized source file type '(x86)\Windows', object file assumed

It looks like we need to get smarter about how we process the ldopts and strip out the ccdlflags and ldflags

Here is an attempt to fix all that. It's ugly, but I think it's more principled.

First, instead of getting the ldopts and then trying to filter out the ldflags and ccdlflags, it tells perl not to include those in the first place, by overriding a couple of routines in ExtUtils::Embed. And second, it's smarter about splitting what's left, so that it doesn't split on a space that's in a quoted item. The perl that's used to do that second bit is not pretty, but it has been tested on the system where the problem arose and apparently cures the problem. (No doubt some perl guru could improve it.) It also works on my Ubuntu system, so I don't think we'll be breaking anything (famous last words).

cheers

andrew

--
Andrew Dunstan
EDB: https://www.enterprisedb.com