gcc-go observations after a few days of usage

[Peter Lemenkov]

Hello All!

I've been using gccgo from GCC 4.8.2 (which fully supports 1.1.2 as
they claimed) for a while now and I've got something to share with
you.

First of all I was surprised that there is a lot of source code
duplication. GCC' libgo/go directory contains the entire
golang/src/pkg directory (with a very few changes if any). I thought
GCC has its own golang's library implementation.

Second - gccgo doesn't really improves situation with different
architectures support (mostly due to that was said above regarding
code duplication). Although it's possible to compile things on PowerPC
(and I suppose on s390(x) as well) the resulting binaries refuse to
run throwing error message about an unsupported architecture.

Otherwise it looks quite good - everything works well. Also from the
visible changes the resulting binaries are significantly smaller (from
megabytes to hundreds of kilobytes) if anyone still care about this.

[Matthew Miller]

On Sun, Oct 27, 2013 at 11:31:15PM +0400, Peter Lemenkov wrote:
> Otherwise it looks quite good - everything works well. Also from the
> visible changes the resulting binaries are significantly smaller (from
> megabytes to hundreds of kilobytes) if anyone still care about this.

Is this due to dynamic linking?

Do you have any idea about golang 1.2 compatibility?

[Peter Lemenkov]

2013/10/28 Matthew Miller :
> On Sun, Oct 27, 2013 at 11:31:15PM +0400, Peter Lemenkov wrote:
> > Otherwise it looks quite good - everything works well. Also from the
> > visible changes the resulting binaries are significantly smaller (from
> > megabytes to hundreds of kilobytes) if anyone still care about this.
>
> Is this due to dynamic linking?

I wouldn't oppose golang and gccgo as "static" vs. "dynamic" since
golang also links dynamically, just only with a fewer libs than gccgo
does. However the answer is yes, gccgo shares much more code across
the binaries with /usr/lib64/libgo.so.4.0.0.

work ~/work/eclus (git::further_systemd_enhancements): ldd eclus.gccgo
eclus.golang
eclus.gccgo:
    linux-vdso.so.1 =>  (0x00007fffb7dfe000)
    libgo.so.4 => /lib64/libgo.so.4 (0x00007f6d39811000)
    libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f6d395f5000)
    libm.so.6 => /lib64/libm.so.6 (0x00007f6d392f2000)
    libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007f6d390dc000)
    libc.so.6 => /lib64/libc.so.6 (0x00007f6d38d1b000)
    /lib64/ld-linux-x86-64.so.2 (0x00007f6d3a550000)
eclus.golang:
    linux-vdso.so.1 =>  (0x00007fffceffe000)
    libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f4a162f6000)
    libc.so.6 => /lib64/libc.so.6 (0x00007f4a15f35000)
    /lib64/ld-linux-x86-64.so.2 (0x00007f4a16533000)
work ~/work/eclus (git::further_systemd_enhancements): ls -la
eclus.gccgo eclus.golang
-rwxrwxr-x. 1 petro petro  518989 окт 22 23:16 eclus.gccgo
-rwxrwxr-x. 1 petro petro 3480336 окт 22 23:17 eclus.golang
work ~/work/eclus (git::further_systemd_enhancements):
> Do you have any idea about golang 1.2 compatibility?

Nope, no idea.