Re: MSVC build broken (on cygwin)

From

Ramsay Jones <ramsay@ramsay1.demon.co.uk>

Date

Oct 3, 2009, 19:36 UTC

Message-ID

<4AC7A7BC.5070608@ramsay1.demon.co.uk>

In-Reply-To

<4AC5B4AE.5070307@gmail.com>

Marius Storm-Olsen wrote:

> ...
> Clone the git://repo.or.cz/msvcgit.git, and run the 
> setup_32bit_env.cmd script in there, and you should have everything 
> you need to both compile and link Git with MSVC.
> 

>> Anyway, the point is *not* to get the msvc build to work for me; rather
>> it is to understand why the build *works* for you. ;-)
> 
> First of all, thanks for the thorough report! :)

You're welcome.

> Second, I just recompiled, and it magically works for me. Why is a 
> good question, since I also think it shouldn't at this point. The

Oh, you *really* don't want "magic" to be the answer... :P

> So, obviously, some magic in there is making it work for me. I have a 
> hard time locating the magic in question though. :-/

In order to fix this issue for me, I made the following change:

-- >8 --

diff --git a/compat/vcbuild/scripts/clink.pl b/compat/vcbuild/scripts/clink.pl
index 0ffd59f..3e4e501 100644
--- a/compat/vcbuild/scripts/clink.pl
+++ b/compat/vcbuild/scripts/clink.pl
@@ -45,4 +45,18 @@ if ($is_linking) {
 	push(@args, @cflags);
 }
 #printf("**** @args\n");
-exit system(@args);
+
+system(@args);
+
+if ($? == -1) {
+	print "clink.pl: failed to execute: $!\n";
+	exit 1;
+}
+elsif ($? & 127) {
+	printf "clink.pl: child died with signal %d%s\n",
+		($? & 127), ($? & 128) ? ', coredump.' : '.';
+	exit 1;
+}
+
+exit $? >> 8;
+
-- >8 --

See "perldoc -f system" for more explanation of the above. This is
how it works on unix and unix-alike systems, so this may not work
too well on (say) ActiveState Perl; Dunno. Also, according to this
documentation, the form of the call to system() should result in a
call to an exec function, rather than using a shell; this may or
may not be true on other platforms.

Having fixed that problem, I modified clink.pl again so that it
would run args.exe rather than cl.exe; this allowed me to see,
using: make -> perl -> "system()" -> args.exe, just what will be
passed to the compiler.

Just in case you can't guess, create args.exe from:

    $ cat -n args.c
         1	#include <stdio.h>
         2	
         3	int main(int argc, char *argv[])
         4	{
         5		int i;
         6	
         7		for (i=0; i< argc; i++) {
         8			printf("argv[%d] = '%s'\n", i, argv[i]);
         9		}
        10		exit(1);
        11	}
        12	
    $ 

and put it somewhere in your path (~/bin for me).

    $ make MSVC=1
    GIT_VERSION = 1.6.5.rc1.38.gb4f27.dirty
        * new build flags or prefix
        CC fast-import.o
    argv[0] = 'args'
    argv[1] = '-Fofast-import.o'
    argv[2] = '-c'
    argv[3] = '-nologo'
    argv[4] = 'fast-import.c'
    argv[5] = '-I.'
    argv[6] = '-I../zlib'
    argv[7] = '-Icompat/vcbuild'
    argv[8] = '-Icompat/vcbuild/include'
    argv[9] = '-DWIN32-D_CONSOLE'
    [...snipped...]
    argv[56] = '-Icompat/regex'
    make: *** [fast-import.o] Error 1

Perhaps you could try a similar exercise?

Hmm, do you have any funny environment variables set which msvc is
picking up? 
Oh, what about the CL variable?

> That being said, does adding the space between the defines fix the 
> MSVC compilation using Cygwin's GNU Make? It's none-the-less a correct 
> patch, so you get an ack from me. Thanks!
> 
> Acked-by: Marius Storm-Olsen <mstormo@gmail.com>
> 

Thanks!

ATB,
Ramsay Jones