https://issues.dlang.org/show_bug.cgi?id=17236

Coming to you on ubuntu soon.

On Fri, Mar 03, 2017 at 06:11:29PM +0000, deadalnix via Digitalmars-d wrote:
> https://issues.dlang.org/show_bug.cgi?id=17236
> 
> Coming to you on ubuntu soon.

I just built dmd/druntime/phobos on Debian, and it works fine.  But then again, I'm using my -fPIC workaround, which has been officially turned down as a viable solution, so *shrug*.

For those who are interested, here's how to do it:

NOTE: this assumes you have a working bootstrap compiler installed in /usr/src/d/install/ (I use 2.069 for this purpose but it should probably work with other recent releases as well).

1) Create a g++ wrapper, say /usr/src/d/g++wrapper, with the following contents:

	#!/bin/sh
	# This is a temporary hack to workaround Phobos being
	# incompatible with gcc-6.2's PIE-by-default configuration in
	# Debian.
	CXX_FLAGS=-no-pie

	if [ "$1" = "--version" ] ; then
		# This is a workaround for posix.mak bogonity in parsing
		# the output of `g++ --version` for certain GCC
		# versions.
		echo g++
		exit 0
	fi
	/usr/bin/g++ $CXX_FLAGS "$@"

2) Build dmd:

	export HOST_DMD=/usr/src/d/install/linux/bin64/dmd
	cd dmd/src
	make -f posix.mak clean
	make -f posix.mak \
		HOST_CXX=/usr/src/d/g++wrapper \
		HOST_DMD="/usr/src/d/install/linux/bin64/dmd -conf=/usr/src/d/install/linux/bin64/dmd.conf" \
		MODEL=64 -j3

3) Build druntime/phobos with PIC=1:

	cd ../../druntime
	make -f posix.mak PIC=1 MODEL=64

	cd ../phobos
	make -f posix.mak PIC=1 MODEL=64

Yes, this makes druntime/phobos PIC, even for static linking, which may introduce performance degradation.  But I'd rather suffer a slight performance degradation than to be unable to use D at all.

Now, if there was a way to coax dmd to invoke g++ with -no-pie (besides using the g++wrapper hack above), I'd be all ears, 'cos that would mean we can build druntime/phobos without PIC=1, and simply have dmd always emit non-PIC / non-PIE code.  However, the last time I tried this, I still ran into problems with dmd-personality / g++-personality symbols that for whatever reason are still incompatible with PIE.

Besides, even if somebody could figure out how to make this work, this still defeats the purpose of PIE-by-default on Debian, so the REAL solution is to implement emitting PIE (but not necessarily PIC) code in dmd.

I hate to say it, knowing how busy Walter/Andrei and the rest of the dmd devs are, but losing Debian/Ubuntu means losing a pretty significant chunk of our userbase, so implementing PIE support in dmd should be a pretty high priority.  But, sorry to say, I doubt anything will happen on this front unless Walter was forced to use Debian for the next 6 months and has to personally face the frustration of being unable to build dmd due to PIE-by-default.


T

-- 
Leather is waterproof.  Ever see a cow with an umbrella?

On Fri, Mar 03, 2017 at 10:32:34AM -0800, H. S. Teoh via Digitalmars-d wrote:
> On Fri, Mar 03, 2017 at 06:11:29PM +0000, deadalnix via Digitalmars-d wrote:
> > https://issues.dlang.org/show_bug.cgi?id=17236
> > 
> > Coming to you on ubuntu soon.
> 
> I just built dmd/druntime/phobos on Debian, and it works fine.  But then again, I'm using my -fPIC workaround, which has been officially turned down as a viable solution, so *shrug*.
[...]

Actually, I just tested on a freshly-cloned copy of dmd/druntime/phobos, it seems that building on Debian does work. Digging into the git log, it appears that commit 78cd023 *should* have added -fPIC to the makefiles.

So how come it's still not working for you?  Are you using an older bootstrap compiler? (If so, the g++wrapper trick I posted should solve that problem -- you can skip the PIC=1 hacks for druntime/phobos as this is apparently already merged into git master.)


T

-- 
Almost all proofs have bugs, but almost all theorems are true. -- Paul Pedersen

On Friday, 3 March 2017 at 18:11:29 UTC, deadalnix wrote:
> https://issues.dlang.org/show_bug.cgi?id=17236
>
> Coming to you on ubuntu soon.

I'm pretty sure that would still work with LDC. So not exactly "nothing". ;)

 – David

On Friday, 3 March 2017 at 18:11:29 UTC, deadalnix wrote:
> https://issues.dlang.org/show_bug.cgi?id=17236
>
> Coming to you on ubuntu soon.

I started a new Docker instance and tried this:

```
docker run -i -t ubuntu:16.10 /bin/bash
apt-get update
apt-get install git curl gcc g++ unzip
git clone https://github.com/dlang/dmd
git clone https://github.com/dlang/druntime
git clone https://github.com/dlang/phobos
cd dmd
make -j8 -f posix.mak  AUTO_BOOTSTRAP=1
cd ../phobos
make -j8 -f posix.mak
```

Everything builds just fine!
As mentioned on a different ticket of yours, I believe it's still an issue with your setup and most likely an outdated DMD binary in `dmd`.
In case you think this isn't the case, please provide a proper bug report.

Moreover, as Martin has stated it before ranting here isn't a nice behavior, especially if it's _not_ our fault and "nothing" just refers to your build setup.

On Friday, 3 March 2017 at 18:47:53 UTC, H. S. Teoh wrote:
> Actually, I just tested on a freshly-cloned copy of dmd/druntime/phobos, it seems that building on Debian does work. Digging into the git log, it appears that commit 78cd023 *should* have added -fPIC to the makefiles.
>
> So how come it's still not working for you?  Are you using an older bootstrap compiler? (If so, the g++wrapper trick I posted should solve that problem -- you can skip the PIC=1 hacks for druntime/phobos as this is apparently already merged into git master.)
>
>
> T

I blasted everything away, reinstalled everything and now it builds....

Something must be broken with make clean then.

On 3/3/17 6:27 PM, deadalnix wrote:
> On Friday, 3 March 2017 at 18:47:53 UTC, H. S. Teoh wrote:
>> Actually, I just tested on a freshly-cloned copy of
>> dmd/druntime/phobos, it seems that building on Debian does work.
>> Digging into the git log, it appears that commit 78cd023 *should* have
>> added -fPIC to the makefiles.
>>
>> So how come it's still not working for you?  Are you using an older
>> bootstrap compiler? (If so, the g++wrapper trick I posted should solve
>> that problem -- you can skip the PIC=1 hacks for druntime/phobos as
>> this is apparently already merged into git master.)
>>
>>
>> T
>
> I blasted everything away, reinstalled everything and now it builds....
>
> Something must be broken with make clean then.

Good to hear, could you please update (if reproducible) or close the issue. Thanks! -- Andrei