fix gcc5 build

[xantares]

gcc 4.6.4 must be patched in order to compile with gcc 5.1.0:
DragonFlyBSD/DPorts#136

[liclac]

Any chance we could update our GCC fork, instead of maintaining this old version? (ping @artart78)

[MrColdbird]

There is more to fix than just this gcc 5.1.0 issue actually.

The produced static libraries don't export the _link symbol, which in turn makes every application that links to the libc / libstdc++ part of those fail to build.

A makeshift way of getting this sorted is to add a dummy _link syscall to the source before building, a sample patch has been posted here:

https://sourceware.org/ml/newlib/2000/msg00401.html

[xantares]

@MrColdbird the patch you point out doesn't change anything, _link is already defined here in newlib 1.20.0:

int
_close (int file)
{
  return __trap34 (SYS_close, file, 0, 0);
}

int
_link (char *old, char *new)
{
  return -1;
}

caddr_t
_sbrk (int incr)

[MrColdbird]

Then we need an explanation why this particular piece isn't getting linked in as a separate symbol.
Do you think a compiler optimization might have inlined this in a bad way?

[xantares]

got it, it's because of the patch, _link is found in newlib/libc/sys/psp/libcglue.c:

#ifdef F__link
int _link(const char *name1, const char *name2)
{
        errno = ENOSYS;
        return -1; /* not supported */
}
#endif

and F__link is not defined anywhere
if I add -DF__link to CFLAGS I got:

$ nm /usr/psp/lib/libc.a --defined-only | grep _link
00000000 T _link
000000bc T _link
00000000 T _link
00000000 T _link
00000198 T _link
00000000 T _link
00000000 T _link
00000000 T _link
00000000 T _link
0000009c T _link
00000000 T _link
00000000 T _link
00000000 T _link
00000000 T _link
00000000 T _link
00000000 T _link_r
00000000 T _link
00000138 T _link
00000074 T _link
00000000 T _link
00000000 T _link
00000000 T _link
000001fc T _link
00000060 T _link
00000000 T _link
000001c0 T _link
000000bc T _link
00000000 T _link
00000068 T _link
00000000 T _link
00000000 T _link
00000000 T _link
time.o_link.o:
00000000 T _link
00000000 T _link
00000000 T _link
00000068 T _link
00000000 T _link
000001c0 T _link

[MrColdbird]

Sweet. Hope to see a commit on your github with it soon then so I can pull it in via your Arch package later today.

[xantares]

unfortunately i get an error caused by multiple references to _link at final build

[xantares]

think i found it:
https://github.com/pspdev/psptoolchain/blob/master/patches/newlib-1.20.0-PSP.patch#L7269

[xantares]

see #56, it's another unrelated issue

[xantares]

@artart78, @uppfinnarn, this one can be merged now, along with #56

[MrColdbird]

Nicely done.

[artart78]

@uppfinnarn, I tried to update the patch to the latest binutils / gcc versions, but IIRC binutils changed to much for the patch to be adapted. Some parts of it probably would need to be rewritten from scratch, and I don't think it's worth it.

Thanks for the fixes @xantares !