Re: [PATCH] Introduce Git.pm (v3)

From: Junio C Hamano <junkio@cox.net>
Date: Jun 23, 2006, 00:22 UTC
Message-ID: <7v1wtghga6.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <20060622235017.GH21864@pasky.or.cz>

Petr Baudis <pasky@suse.cz> writes:

Show 13 quoted lines

>> Eek.  It does not compile for me -- maybe there is more
>> dependencies that need to be listed in INSTALL file?
>> ...
>> Git.xs: In function 'XS_Git_xs_hash_object':
>> Git.xs:27: warning: ISO C90 forbids mixed declarations and code
>> Git.xs:44: warning: passing argument 1 of 'Perl_io_close' from incompatible pointer type
>> Git.xs:44: warning: passing argument 2 of 'Perl_io_close' makes pointer from integer without a cast
>> Git.xs:44: error: too few arguments to function 'Perl_io_close'
>
> Oops, sorry. Apparently, I've digged too deep and unleashed a monster of
> unstable API. Now I've finally discovered perlapio(1) and know I
> should've just called PerlIO_close(). Below comes a fixed patch, I
> didn't bother to bump the version number.

Thanks; it compiles now with a few more glitches.

            /usr/bin/perl /usr/share/perl/5.8/ExtUtils/xsubpp  \
                    -typemap /usr/share/perl/5.8/ExtUtils/typemap  Git.xs > Git.xsc && \
                    mv Git.xsc Git.c
            Please specify prototyping behavior for Git.xs (see perlxs manual)

Says xsubpp.

        cc -c  -I. -I.. -D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS \
                -DDEBIAN -fno-strict-aliasing -pipe -I/usr/local/include \
                -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -O2 \
                -DVERSION=\"0.01\" -DXS_VERSION=\"0.01\" -fPIC \
                "-I/usr/lib/perl/5.8/CORE" -Wall
                -Wdeclaration-after-statement \
                -g -DSHA1_HEADER='<openssl/sha.h>' \
                -DGIT_VERSION=\"1.4.1.rc1.g01a1\" Git.c
        Git.xs: In function 'XS_Git_xs__execv_git_cmd':
        Git.xs:57: warning: passing argument 1 of 'free' discards qualifiers from pointer target type
        Git.xs: In function 'XS_Git_xs_hash_object':
        Git.xs:65: warning: ISO C90 forbids mixed declarations and code

I usually compile with -Wdeclaration-after-statement so I probably get some more warnings than you saw; it probably is primarily xsubpp's fault, but you could work it around by having CODE block to be inside an extra set of braces {}. Constness reduction of free() is a bit annoying from the point of view of the coder who has to cast away constness, so I won't be too strict about that, but it would be nicer if we did not have to see the warnings.

        rm -f blib/arch/auto/Git/Git.so
        cc  -shared -L/usr/local/lib Git.o  -o blib/arch/auto/Git/Git.so ../libgit.a	\
                   -lz -lcrypto  	\

        /usr/bin/ld: ../libgit.a(exec_cmd.o): relocation R_X86_64_32 against `a local symbol' can not be used when making a shared object; recompile with -fPIC
        ../libgit.a: could not read symbols: Bad value
        collect2: ld returned 1 exit status
        make[1]: *** [blib/arch/auto/Git/Git.so] Error 1

This is a real killer. If we compile everything with -fPIC, this goes away, but I do not think we want -fPIC for the core level tools. At least not until we are ready to do libgit.so.