Re: Mac OS 9 (Lamp) port

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On May 30, 2010, at 8:19 PM, Jonathan Nieder wrote:

Joshua Juran wrote:

http://github.com/jjuran/git.git

Apparently <http://github.com/jjuran/git> works better.

I assume the lamp-git branch is the interesting one.  Some of

The lamp-git branch is the one you'd checkout to build git. It merges the interesting ones.

these patches (e.g., a3b378781) look like they might be of general

$ git show a3b378781
commit a3b378781228d59a13ee055d06c8f5465b543178
Author: Joshua Juran <jjuran@xxxxxxxxxxxx>
Date:   Sun Nov 29 03:57:54 2009 -0800

Avoid pointless use of one-celled array (which also confounds Metrowerks C).

Pass the address of fetch_refspec_str directly to parse_refspec_internal()
    instead of copying fetch_refspec_str to an array and passing that.

Metrowerks C won't initialize aggregates with values determined at runtime, and we can't use the C++ translator for parse_refspec_internal() because it uses the same identifier (refspec) for a variable as an existing struct type.

    That, and there's no purpose to the array in the first place.

diff --git a/remote.c b/remote.c
index c70181c..ade0424 100644
--- a/remote.c
+++ b/remote.c
@@ -657,10 +657,9 @@ static struct refspec *parse_refspec_internal (int nr_refspec, const char **refsp

 int valid_fetch_refspec(const char *fetch_refspec_str)
 {
-       const char *fetch_refspec[] = { fetch_refspec_str };
        struct refspec *refspec;

-       refspec = parse_refspec_internal(1, fetch_refspec, 1, 1);
+       refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
        free_refspecs(refspec, 1);
        return !!refspec;
 }

Yes, this is the patch I suggested to Gary V. Vaughan.

interest, while others (e.g., 6e6b106d) reveal Metrowerks to be
a bit braindead.

$ git show 6e6b106d
commit 6e6b106dd6c561db726f90e2db07beeef1f716f9
Author: Joshua Juran <jjuran@xxxxxxxxxxxx>
Date:   Wed Apr 8 01:51:04 2009 -0700

    Cast compare_info() arguments to (const struct pack_info *const *).

Otherwise, Metrowerks C reports "illegal implicit conversion from 'const void *'
    to 'struct pack_info *const *'".

diff --git a/server-info.c b/server-info.c
index 4098ca2..a9a0188 100644
--- a/server-info.c
+++ b/server-info.c
@@ -132,8 +132,8 @@ static int read_pack_info_file(const char *infofile)

 static int compare_info(const void *a_, const void *b_)
 {
-       struct pack_info *const *a = a_;
-       struct pack_info *const *b = b_;
+       const struct pack_info *const *a = a_;
+       const struct pack_info *const *b = b_;

        if (0 <= (*a)->old_num && 0 <= (*b)->old_num)
                /* Keep the order in the original */

I certainly won't defend Metrowerks C 2.4.1, but the patch is harmless enough.

Have you thought about getting git to compile in C++ mode, where

If the Git maintainers are interested in this, I'm glad to do it. I expect it to require generally less maintenance than my c++- initializer-fix branch, which is rather ugly to boot.

Metrowerks might be a little more sane[1]?  Sure, this runs into

Well, I wasn't going to suggest general C++ compatibility just for my port, but if there's interest, then yes, that would obviate my (by far) largest and nastiest patch.

basically all the major incompatibilities between C and C++[2], but
that might not be insurmountable:

Writing code which is both valid C and valid C++ is not difficult.

 . No implicit conversion from void* to other: don’t use void *,
   then.  With type-safe interfaces like

#define typed_malloc(size, type) (type *)xmalloc(size)
#define malloc_many(nmemb, type) typed_malloc((nmemb) * sizeof (type), type)

   one can take advantage of type checking without the annoyance of
   casts at the call site.

Replacing xmalloc(size) with typed_malloc(size, struct foo) instead of (struct foo *)xmalloc(size) still feels like a cast to me. IMHO it adds no safety and reduces readability.

Maybe you could have:

	#define alloc_n(type, n)  ((type*)xmalloc(sizeof (type) * n))

to factor the multiplication out of the calling code. But for a plain data buffer, nothing is shorter or clearer than a simple (char*) cast.

   Another place git uses void * is for low-level access to the
   object database, because it is not obvious whether objects data
   should use char * or unsigned char *.  unsigned char * should
   be fine.

If there were a configurable typedef defining this, I'd use char* since the Metrowerks debugger by default displays it as a C string (as opposed to a Pascal string for unsigned char* -- it's a Mac OS convention). But that's a minor point and not one I'd spend time advocating.

 . Use of C++ keywords:

#ifdef __cplusplus
#define template git_template
#define typename git_typename
#endif

   It is not like this is an actual C++ program.

My c++initializer-fix patch does this locally in a few places. I suppose it makes sense to nail them all at once in git-compat-util.h.

 . Assignment of ints to enums is forbidden: okay, this one is
   not worth working around.  Does Metrowerks have an option to turn
   off this piece of C++ insanity?

It's a feature. :-) I use enums for type-safety in my C++ POSIX wrapper library. p7::wait() returns p7::wait_t, and if you try to pass that to p7::exit() (which takes p7::exit_t) you get a compile error (instead of a program that 'works' when the wait status is zero).

(No, I'm not aware of an option to disable this restriction.)

If you want the type-safety, you have to pay for it. Otherwise, declare variables and parameters as integral types instead. I don't care one way or the other -- I just want git to work on Lamp, and if there's community interest in C++ compatibility then I can assist with that.

Josh

P.S. Every patch in my git repository is Signed-off-by: Joshua Juran <jjuran@xxxxxxxxx> (or s/gmail/metamage/).


--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Kernel Development]     [Gcc Help]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [V4L]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]     [Fedora Users]