Need -lgcc for tttt build

[DanielO]

Hi, I am following http://zipcpu.com/zipcpu/2018/02/12/zbasic-intro.html and I got this trying to build tttt:

[ubuntu 13:45] /media/psf/Home/projects/zbasic/sw/board >make tttt
CROSS=zip- ARCH=zip make --no-print-directory -C tttt/src ARCH=zip CROSS=zip- zip-tttt
Building dependency file
zip-gcc -T../../../zlib/../board/board.ld obj-zip/comborow.o obj-zip/comboset.o obj-zip/gboard.o obj-zip/strategy.o obj-zip/vset.o obj-zip/main.o -L../../../zlib -Wl,--start-group -Wl,--Map=zip-tttt.map -lzbasic -lc -lg -o zip-tttt
/media/psf/Home/projects/zipcpu/sw/install/cross-tools/lib/gcc/zip/6.2.0/../../../../zip/lib/libc.a(lib_a-vfprintf.o): In function `_vfprintf_r':
vfprintf.c:(.text+0x648): undefined reference to `__unorddf2'
vfprintf.c:(.text+0x664): undefined reference to `__ledf2'
vfprintf.c:(.text+0x7f8): undefined reference to `__eqdf2'
vfprintf.c:(.text+0x1470): undefined reference to `__eqdf2'
vfprintf.c:(.text+0x1b1c): undefined reference to `__nedf2'
vfprintf.c:(.text+0x1f28): undefined reference to `__unorddf2'
vfprintf.c:(.text+0x1f48): undefined reference to `__ltdf2'
vfprintf.c:(.text+0x2004): undefined reference to `__nedf2'
/media/psf/Home/projects/zipcpu/sw/install/cross-tools/lib/gcc/zip/6.2.0/../../../../zip/lib/libc.a(lib_a-dtoa.o): In function `_dtoa_r':
dtoa.c:(.text+0x2c4): undefined reference to `__eqdf2'
dtoa.c:(.text+0x3a0): undefined reference to `__floatunsidf'
dtoa.c:(.text+0x3c0): undefined reference to `__subdf3'
dtoa.c:(.text+0x3d8): undefined reference to `__muldf3'
dtoa.c:(.text+0x3f0): undefined reference to `__adddf3'
dtoa.c:(.text+0x400): undefined reference to `__floatsidf'
<snip>

I found it necessary to add -lgcc to the XLIBS line.

[ZipCPU]

Good catch!

I didn't initially use -lgcc, but became needed once I was able to build it because it provided soft-floating point.

I should probably place -lgcc into the default command line for the tools to fix this. For now, I expect to just change the zbasic instructions.

Dan

[DanielO]

OK, I wasn't sure where to file it since your blog doesn't have a bug tracker ;)

WRT needing it - I think it does depend on your compiler version but it's mostly black magic to me..

[ZipCPU]

Yeah, "mostly black magic".

I'm still looking for the "right way" to handle this fix. Part of the difficulty is that -lgcc depends upon the C library, but you shouldn't need to specify "-lc -lgcc" on the command line (which I just had to do for a project), so this is definitely an issue and I'm looking into it. At least for now there's a work around, but it's not really the solution I want. I'm going to leave this open until I figure it out.