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digitalmars.D - DMD Backend Long-term

reply dsimcha <dsimcha yahoo.com> writes:
What is the long-term plan for the current DMD backend?  I've noticed the
first steps towards 64-bit support were just checked in today (excitement to
the extreme).  However, the backend is under such a restrictive license (which
I understand Walter is not free to change) that it has a "bus factor" of 1.
If Walter were to stop maintaining it, noone else would be able to, if I
understand the licensing issues correctly.

Is there a chance of these licensing issues being cleared up so that the
backend can be released under a more permissive license?  If not, while I
understand Walter's decision to use a backend he was familiar with in the
beginning, it seems like we should abandon such a heavily encumbered backend
now that it needs serious work.
Jun 21 2010
next sibling parent Sean Kelly <sean invisibleduck.org> writes:
dsimcha <dsimcha yahoo.com> wrote:
 What is the long-term plan for the current DMD backend?  I've noticed
 the
 first steps towards 64-bit support were just checked in today
 (excitement to
 the extreme).  However, the backend is under such a restrictive
 license (which
 I understand Walter is not free to change) that it has a "bus factor"
 of 1.
 If Walter were to stop maintaining it, noone else would be able to, if
 I
 understand the licensing issues correctly.
 
 Is there a chance of these licensing issues being cleared up so that
 the
 backend can be released under a more permissive license?  If not,
 while I
 understand Walter's decision to use a backend he was familiar with in
 the
 beginning, it seems like we should abandon such a heavily encumbered
 backend
 now that it needs serious work.

I think it makes complete sense for the DigitalMars D compiler to use the DigitalMars backend. What we really need is more community work on compilers using other backends (GDC, LLVMDC) as well. The language can only benefit from having more than one compiler available.
Jun 21 2010
prev sibling next sibling parent reply Eldar Insafutdinov <e.insafutdinov gmail.com> writes:
== Quote from dsimcha (dsimcha yahoo.com)'s article
 What is the long-term plan for the current DMD backend?  I've noticed the
 first steps towards 64-bit support were just checked in today (excitement to
 the extreme).  However, the backend is under such a restrictive license (which
 I understand Walter is not free to change) that it has a "bus factor" of 1.
 If Walter were to stop maintaining it, noone else would be able to, if I
 understand the licensing issues correctly.
 Is there a chance of these licensing issues being cleared up so that the
 backend can be released under a more permissive license?  If not, while I
 understand Walter's decision to use a backend he was familiar with in the
 beginning, it seems like we should abandon such a heavily encumbered backend
 now that it needs serious work.

Hi I agree with what Sean says. Even more, DMD backend is good for development process, because it is very fast as opposed to more popular ones like llvm or gcc. What really worries me is what is going to happen on Windows. We have the burden which is old file format and optlink. There are still big problems with the linker, it has random problems on big projects, building them with debug info is even more problematic. As far as I understood that linker is being rewritten to C, but the process is very slow. It may take years to complete the port, and then to make it 64bit capable, isn't it? All existing problems would be propagated further. I would suggest(again and again) to add a new Windows backend targeting MinGW or MSVC toolchain. It should not necessarily replace the existing one, but people would at least have freedom and there wouldn't be situation that you are stuck in development when linker fails. Also those toolchain support 64bit, so it is another advantage. For those who still wants digital mars toolchain - there will be an old one. Remembering that it took Walter about 6 weeks to implement MacOS backend, that doesn't seem too bad. In the end, Windows is the most popular OS despite our personal preferences, and it's worth spending some time for it. Cheers
Jun 21 2010
parent "Nick Sabalausky" <a a.a> writes:
"Eldar Insafutdinov" <e.insafutdinov gmail.com> wrote in message 
news:hvo49k$1uk3$1 digitalmars.com...
 In the end, Windows is the most popular
 OS despite our personal preferences, and it's worth spending some time for 
 it.

I wish someone could convince LLVM of that...
Jun 21 2010
prev sibling next sibling parent reply Robert Clipsham <robert octarineparrot.com> writes:
On 21/06/10 16:07, dsimcha wrote:
 What is the long-term plan for the current DMD backend?  I've noticed the
 first steps towards 64-bit support were just checked in today (excitement to
 the extreme).  However, the backend is under such a restrictive license (which
 I understand Walter is not free to change) that it has a "bus factor" of 1.
 If Walter were to stop maintaining it, noone else would be able to, if I
 understand the licensing issues correctly.

 Is there a chance of these licensing issues being cleared up so that the
 backend can be released under a more permissive license?  If not, while I
 understand Walter's decision to use a backend he was familiar with in the
 beginning, it seems like we should abandon such a heavily encumbered backend
 now that it needs serious work.

Perhaps the 64bit backend could be written in such a way that it doesn't have the licensing issues? I have no idea what the specifics are to say if this is possible, it'd be good to not have the 64 bit backend under the current backend license though.
Jun 21 2010
parent BCS <none anon.com> writes:
Hello Robert,

 On 21/06/10 16:07, dsimcha wrote:
 
 What is the long-term plan for the current DMD backend?  I've noticed
 the
 first steps towards 64-bit support were just checked in today
 (excitement to
 the extreme).  However, the backend is under such a restrictive
 license (which
 I understand Walter is not free to change) that it has a "bus factor"
 of 1.
 If Walter were to stop maintaining it, noone else would be able to,
 if I
 understand the licensing issues correctly.
 Is there a chance of these licensing issues being cleared up so that
 the backend can be released under a more permissive license?  If not,
 while I understand Walter's decision to use a backend he was familiar
 with in the beginning, it seems like we should abandon such a heavily
 encumbered backend now that it needs serious work.
 

doesn't have the licensing issues? I have no idea what the specifics are to say if this is possible, it'd be good to not have the 64 bit backend under the current backend license though.

I'm going to guess that about half of the object file generator and nearly 100% of everything before the code generator will be the same for 32 and 64 bit. And at a wild guess I'm going to say that's much more than half the code in the back end. Add an error factor for me guessing and you can do the math. :(
 

... <IXOYE><
Jun 21 2010
prev sibling next sibling parent reply Leandro Lucarella <luca llucax.com.ar> writes:
Nick Sabalausky, el 21 de junio a las 13:40 me escribiste:
 "Eldar Insafutdinov" <e.insafutdinov gmail.com> wrote in message 
 news:hvo49k$1uk3$1 digitalmars.com...
 In the end, Windows is the most popular
 OS despite our personal preferences, and it's worth spending some time for 
 it.

I wish someone could convince LLVM of that...

Maybe it should be the other way around. Someone who cares about Windows should give some love to LLVM =) -- Leandro Lucarella (AKA luca) http://llucax.com.ar/ ---------------------------------------------------------------------- GPG Key: 5F5A8D05 (F8CD F9A7 BF00 5431 4145 104C 949E BFB6 5F5A 8D05) ---------------------------------------------------------------------- Es mucho mas probable que el salchichón sea primavera a que la primavera sea salchichón. -- Peperino Pómoro
Jun 21 2010
next sibling parent reply BCS <none anon.com> writes:
Hello Leandro,

 Nick Sabalausky, el 21 de junio a las 13:40 me escribiste:
 
 "Eldar Insafutdinov" <e.insafutdinov gmail.com> wrote in message
 news:hvo49k$1uk3$1 digitalmars.com...
 
 In the end, Windows is the most popular
 OS despite our personal preferences, and it's worth spending some
 time for
 it.


Windows should give some love to LLVM =)

How hard are the problems? I have zero experience in LLVM and very little in compiler work but if the problems could be attacked without to much ramp-up I'd be interested in looking into them. -- ... <IXOYE><
Jun 21 2010
parent Kagamin <spam here.lot> writes:
Robert Jacques Wrote:

 The main issue (as I understand it) is adding windows style structured  
 exception handling to LLVM.

C++ compiles for me. Or are there some other issues?
Jun 22 2010
prev sibling next sibling parent reply "Robert Jacques" <sandford jhu.edu> writes:
On Mon, 21 Jun 2010 23:55:48 -0400, BCS <none anon.com> wrote:

 Hello Leandro,

 Nick Sabalausky, el 21 de junio a las 13:40 me escribiste:

 "Eldar Insafutdinov" <e.insafutdinov gmail.com> wrote in message
 news:hvo49k$1uk3$1 digitalmars.com...

 In the end, Windows is the most popular
 OS despite our personal preferences, and it's worth spending some
 time for
 it.


Windows should give some love to LLVM =)

How hard are the problems? I have zero experience in LLVM and very little in compiler work but if the problems could be attacked without to much ramp-up I'd be interested in looking into them.

The main issue (as I understand it) is adding windows style structured exception handling to LLVM.
Jun 21 2010
next sibling parent reply BCS <none anon.com> writes:
Hello Robert,

 On Mon, 21 Jun 2010 23:55:48 -0400, BCS <none anon.com> wrote:
 
 Hello Leandro,
 
 Nick Sabalausky, el 21 de junio a las 13:40 me escribiste:
 
 "Eldar Insafutdinov" <e.insafutdinov gmail.com> wrote in message
 news:hvo49k$1uk3$1 digitalmars.com...
 
 In the end, Windows is the most popular
 OS despite our personal preferences, and it's worth spending some
 time for
 it.


Windows should give some love to LLVM =)

little in compiler work but if the problems could be attacked without to much ramp-up I'd be interested in looking into them.

exception handling to LLVM.

After a little digging it seems that LLVM legally CAN'T add SEH as MS has it under patent. I'm still digging to figure out how it could be patented without making SEH an irrelevant technology. -- ... <IXOYE><
Jun 22 2010
next sibling parent reply "Nick Sabalausky" <a a.a> writes:
"Robert Jacques" <sandford jhu.edu> wrote in message 
news:op.vepzxsdx26stm6 sandford...
 On Tue, 22 Jun 2010 16:47:14 -0400, BCS <none anon.com> wrote:

 Hello Robert,

 On Mon, 21 Jun 2010 23:55:48 -0400, BCS <none anon.com> wrote:

 The main issue (as I understand it) is adding windows style structured
 exception handling to LLVM.

After a little digging it seems that LLVM legally CAN'T add SEH as MS has it under patent. I'm still digging to figure out how it could be patented without making SEH an irrelevant technology.

The patent seems to be Borlands's: USPTO patent #5,628,016 Patent held by Borland on compiler support for SEH. From a Wine wiki page: http://wiki.winehq.org/CompilerExceptionSupport It does seem to expire on June 15, 2014, though and I assume DigitalMars has a license, so a LLVM fork is not unreasonable.

Seems a weak reason. A programmer that's worried about infringing software patents can't write anything more useful than "Hello World". I'm seriously not convinced at all that it's even possible to write useful code that doesn't technically infringe on some software patent. As a programmer, either you accept the fact that what you do is inevitably going to trample software patents, or you just simply don't be a programmer. That's all there is.
Jun 22 2010
next sibling parent reply Brad Roberts <braddr slice-2.puremagic.com> writes:
On Tue, 22 Jun 2010, Nick Sabalausky wrote:

 Seems a weak reason. A programmer that's worried about infringing software 
 patents can't write anything more useful than "Hello World". I'm seriously 
 not convinced at all that it's even possible to write useful code that 
 doesn't technically infringe on some software patent. As a programmer, 
 either you accept the fact that what you do is inevitably going to trample 
 software patents, or you just simply don't be a programmer. That's all there 
 is.

The world's not nearly that black and white. There's a huge difference in infringment in an app you write for yourself vs an app that's very public. LLVM is somewhat closer to the latter end of the spectrum. I agree that excess paranoia isn't warranted, but neither is willful ignorance.
Jun 22 2010
next sibling parent reply dsimcha <dsimcha yahoo.com> writes:
== Quote from Brad Roberts (braddr slice-2.puremagic.com)'s article
 On Tue, 22 Jun 2010, Nick Sabalausky wrote:
 Seems a weak reason. A programmer that's worried about infringing software
 patents can't write anything more useful than "Hello World". I'm seriously
 not convinced at all that it's even possible to write useful code that
 doesn't technically infringe on some software patent. As a programmer,
 either you accept the fact that what you do is inevitably going to trample
 software patents, or you just simply don't be a programmer. That's all there
 is.

infringment in an app you write for yourself vs an app that's very public. LLVM is somewhat closer to the latter end of the spectrum. I agree that excess paranoia isn't warranted, but neither is willful ignorance.

If we're really lucky, Bilski Vs. Kappos (http://en.wikipedia.org/wiki/In_re_Bilski) will send all the software patent attorneys to the poorhouse next week and we can just start trampling freely.
Jun 22 2010
next sibling parent reply BCS <none anon.com> writes:
Hello dsimcha,

 == Quote from Brad Roberts (braddr slice-2.puremagic.com)'s article
 
 On Tue, 22 Jun 2010, Nick Sabalausky wrote:
 
 Seems a weak reason. A programmer that's worried about infringing
 software patents can't write anything more useful than "Hello
 World". I'm seriously not convinced at all that it's even possible
 to write useful code that doesn't technically infringe on some
 software patent. As a programmer, either you accept the fact that
 what you do is inevitably going to trample software patents, or you
 just simply don't be a programmer. That's all there is.
 

difference in infringment in an app you write for yourself vs an app that's very public. LLVM is somewhat closer to the latter end of the spectrum. I agree that excess paranoia isn't warranted, but neither is willful ignorance.

(http://en.wikipedia.org/wiki/In_re_Bilski) will send all the software patent attorneys to the poorhouse next week and we can just start trampling freely.

OTOH, based on the wiki, the court seems to support a "Machine-or-transformation test" and what is a compiler if not a transformation tool? -- ... <IXOYE><
Jun 22 2010
parent reply dsimcha <dsimcha yahoo.com> writes:
== Quote from BCS (none anon.com)'s article
 Hello dsimcha,
 == Quote from Brad Roberts (braddr slice-2.puremagic.com)'s article

 On Tue, 22 Jun 2010, Nick Sabalausky wrote:

 Seems a weak reason. A programmer that's worried about infringing
 software patents can't write anything more useful than "Hello
 World". I'm seriously not convinced at all that it's even possible
 to write useful code that doesn't technically infringe on some
 software patent. As a programmer, either you accept the fact that
 what you do is inevitably going to trample software patents, or you
 just simply don't be a programmer. That's all there is.

difference in infringment in an app you write for yourself vs an app that's very public. LLVM is somewhat closer to the latter end of the spectrum. I agree that excess paranoia isn't warranted, but neither is willful ignorance.

(http://en.wikipedia.org/wiki/In_re_Bilski) will send all the software patent attorneys to the poorhouse next week and we can just start trampling freely.

test" and what is a compiler if not a transformation tool?

Bits are not a "particular article".
Jun 22 2010
parent BCS <none anon.com> writes:
Hello dsimcha,

 == Quote from BCS (none anon.com)'s article
 
 Hello dsimcha,
 
 == Quote from Brad Roberts (braddr slice-2.puremagic.com)'s article
 
 On Tue, 22 Jun 2010, Nick Sabalausky wrote:
 
 Seems a weak reason. A programmer that's worried about infringing
 software patents can't write anything more useful than "Hello
 World". I'm seriously not convinced at all that it's even possible
 to write useful code that doesn't technically infringe on some
 software patent. As a programmer, either you accept the fact that
 what you do is inevitably going to trample software patents, or
 you just simply don't be a programmer. That's all there is.
 

difference in infringment in an app you write for yourself vs an app that's very public. LLVM is somewhat closer to the latter end of the spectrum. I agree that excess paranoia isn't warranted, but neither is willful ignorance.

(http://en.wikipedia.org/wiki/In_re_Bilski) will send all the software patent attorneys to the poorhouse next week and we can just start trampling freely.

"Machine-or-transformation test" and what is a compiler if not a transformation tool?


We can hope! (I never said I supported software patents :) -- ... <IXOYE><
Jun 22 2010
prev sibling parent reply BCS <none anon.com> writes:
Hello dsimcha,


 If we're really lucky, Bilski Vs. Kappos
 (http://en.wikipedia.org/wiki/In_re_Bilski) will send all the software
 patent attorneys to the poorhouse next week and we can just start
 trampling freely.

FWIW: http://www.supremecourt.gov/opinions/09pdf/08-964.pdf -- ... <IXOYE><
Jun 28 2010
parent reply "Nick Sabalausky" <a a.a> writes:
"BCS" <none anon.com> wrote in message 
news:a6268ff167c88cce5058a18ca78 news.digitalmars.com...
 Hello dsimcha,


 If we're really lucky, Bilski Vs. Kappos
 (http://en.wikipedia.org/wiki/In_re_Bilski) will send all the software
 patent attorneys to the poorhouse next week and we can just start
 trampling freely.

FWIW: http://www.supremecourt.gov/opinions/09pdf/08-964.pdf

Can someone decode that?
Jul 06 2010
parent David Gileadi <gileadis NSPMgmail.com> writes:
On 7/6/10 11:35 AM, Nick Sabalausky wrote:
 "BCS"<none anon.com>  wrote in message
 news:a6268ff167c88cce5058a18ca78 news.digitalmars.com...
 Hello dsimcha,


 If we're really lucky, Bilski Vs. Kappos
 (http://en.wikipedia.org/wiki/In_re_Bilski) will send all the software
 patent attorneys to the poorhouse next week and we can just start
 trampling freely.

FWIW: http://www.supremecourt.gov/opinions/09pdf/08-964.pdf

Can someone decode that?

In case that wasn't simply a commentary on unreadable legalese, here's what Ars Technica said about it: http://arstechnica.com/tech-policy/news/2010/06/supreme-court-allows-but-limits-business-method-patents.ars
Jul 06 2010
prev sibling next sibling parent BCS <none anon.com> writes:
Hello Brad,


 I agree that excess paranoia isn't warranted, but neither is willful
 ignorance.

Willful ignorance is the recommendation in some shops as it avoids triple damages. -- ... <IXOYE><
Jun 22 2010
prev sibling parent Brad Roberts <braddr puremagic.com> writes:
On 6/22/2010 7:07 PM, BCS wrote:
 Hello Brad,
 
 
 I agree that excess paranoia isn't warranted, but neither is willful
 ignorance.

Willful ignorance is the recommendation in some shops as it avoids triple damages.

What I meant was s/ignorance/infringement/.. major disconnect between brain and keyboard there. Actually, most business (at least those smart enough to pay attention to patents and the dangers involved) encourage encapsulated ignorance. Engineers stay in the dark but the legal teams stay informed and guide the engineers away from likely landmines if needed. And that's likely about all I should talk about this subject. In fact, most of this thread is worth dropping as not really helping anyone or anything. If you're concerned, consult a lawyer. Later, Brad
Jun 22 2010
prev sibling parent reply BCS <none anon.com> writes:
Hello Nick,

 "Robert Jacques" <sandford jhu.edu> wrote in message
 news:op.vepzxsdx26stm6 sandford...
 
 On Tue, 22 Jun 2010 16:47:14 -0400, BCS <none anon.com> wrote:
 
 Hello Robert,
 
 On Mon, 21 Jun 2010 23:55:48 -0400, BCS <none anon.com> wrote:
 
 The main issue (as I understand it) is adding windows style
 structured exception handling to LLVM.
 

MS has it under patent. I'm still digging to figure out how it could be patented without making SEH an irrelevant technology.

USPTO patent #5,628,016 Patent held by Borland on compiler support for SEH. From a Wine wiki page: http://wiki.winehq.org/CompilerExceptionSupport It does seem to expire on June 15, 2014, though and I assume DigitalMars has a license, so a LLVM fork is not unreasonable.

software patents can't write anything more useful than "Hello World". I'm seriously not convinced at all that it's even possible to write useful code that doesn't technically infringe on some software patent. As a programmer, either you accept the fact that what you do is inevitably going to trample software patents, or you just simply don't be a programmer. That's all there is.

Or keep an eye on what people have actually been sued over and don't do that. In this case I'd be surprised if it could stand up in court. Unless SEH is insanely convoluted to implement I can't see how the patent passes the non-obviousness criteria. http://en.wikipedia.org/wiki/Inventive_step_and_non-obviousness I wonder if you can get a patent thrown out as invalid without someone infringing on it? -- ... <IXOYE><
Jun 22 2010
parent reply "Nick Sabalausky" <a a.a> writes:
"BCS" <none anon.com> wrote in message 
news:a6268ff157f28cce05385dcf99a news.digitalmars.com...
 Hello Nick,

 Seems a weak reason. A programmer that's worried about infringing
 software patents can't write anything more useful than "Hello World".
 I'm seriously not convinced at all that it's even possible to write
 useful code that doesn't technically infringe on some software patent.
 As a programmer, either you accept the fact that what you do is
 inevitably going to trample software patents, or you just simply don't
 be a programmer. That's all there is.

Or keep an eye on what people have actually been sued over and don't do that. In this case I'd be surprised if it could stand up in court.

Especially since the Plaintiff would apperently be the modern-day Borland. Do they even exist anymore? If they do, would they even be able to afford a lawyer?
 Unless SEH is insanely convoluted to implement I can't see how the patent 
 passes the non-obviousness criteria.

 http://en.wikipedia.org/wiki/Inventive_step_and_non-obviousness

 I wonder if you can get a patent thrown out as invalid without someone 
 infringing on it?

I've wondered that, too. Actually, I've wondered that about US laws in general. Being a US citizen (and having passed the manditory "American Government" class in high school) I probably *should* know... :/
Jun 22 2010
parent reply BCS <none anon.com> writes:
Hello Nick,

 "BCS" <none anon.com> wrote in message
 news:a6268ff157f28cce05385dcf99a news.digitalmars.com...
 
 Hello Nick,
 
 Seems a weak reason. A programmer that's worried about infringing
 software patents can't write anything more useful than "Hello
 World". I'm seriously not convinced at all that it's even possible
 to write useful code that doesn't technically infringe on some
 software patent. As a programmer, either you accept the fact that
 what you do is inevitably going to trample software patents, or you
 just simply don't be a programmer. That's all there is.
 

do that. In this case I'd be surprised if it could stand up in court.

Borland. Do they even exist anymore? If they do, would they even be able to afford a lawyer?

Yes they could, MS bought it (I'm not sure if that's the patent or the company, but MS has it now).
 Unless SEH is insanely convoluted to implement I can't see how the
 patent passes the non-obviousness criteria.
 
 http://en.wikipedia.org/wiki/Inventive_step_and_non-obviousness
 
 I wonder if you can get a patent thrown out as invalid without
 someone infringing on it?

I've wondered that, too. Actually, I've wondered that about US laws in general. Being a US citizen (and having passed the manditory "American Government" class in high school) I probably *should* know... :/

In the US we have two kinds of laws; the kind nobody should need and the kind nobody understands. ;) -- ... <IXOYE><
Jun 22 2010
parent "Nick Sabalausky" <a a.a> writes:
"BCS" <none anon.com> wrote in message 
news:a6268ff1582d8cce06addc4dc7e news.digitalmars.com...
 Hello Nick,

 "BCS" <none anon.com> wrote in message
 news:a6268ff157f28cce05385dcf99a news.digitalmars.com...

 Hello Nick,

 Seems a weak reason. A programmer that's worried about infringing
 software patents can't write anything more useful than "Hello
 World". I'm seriously not convinced at all that it's even possible
 to write useful code that doesn't technically infringe on some
 software patent. As a programmer, either you accept the fact that
 what you do is inevitably going to trample software patents, or you
 just simply don't be a programmer. That's all there is.

do that. In this case I'd be surprised if it could stand up in court.

Borland. Do they even exist anymore? If they do, would they even be able to afford a lawyer?

Yes they could, MS bought it (I'm not sure if that's the patent or the company, but MS has it now).

Hmm. That means the LLVM devs themselves would be safe, but companies using it would get extorted ( http://www.computerworlduk.com/toolbox/open-source/blogs/index.cfm?en ryid=1953&blogid=14 and http://news.cnet.com/8301-13860_3-10206988-56.html ).
 Unless SEH is insanely convoluted to implement I can't see how the
 patent passes the non-obviousness criteria.

 http://en.wikipedia.org/wiki/Inventive_step_and_non-obviousness

 I wonder if you can get a patent thrown out as invalid without
 someone infringing on it?

I've wondered that, too. Actually, I've wondered that about US laws in general. Being a US citizen (and having passed the manditory "American Government" class in high school) I probably *should* know... :/

In the US we have two kinds of laws; the kind nobody should need and the kind nobody understands. ;)

Heh :)
Jun 23 2010
prev sibling parent reply bearophile <bearophileHUGS lycos.com> writes:
Robert Jacques:
 The patent seems to be Borlands's:
 USPTO patent #5,628,016 Patent held by Borland on compiler support for SEH.
  From a Wine wiki page: http://wiki.winehq.org/CompilerExceptionSupport
 
 It does seem to expire on June 15, 2014, though and I assume DigitalMars  
 has a license, so a LLVM fork is not unreasonable.

On Windows G++ supports exceptions. I have two questions: 1) Do you know how they do this? Do they have a license? If they have a licence why don't LLVM people too have it? 2) Why isn't LLVM just copying that part of the GCC code? If a true copy is not possible, why aren't copying the code with enough cosmetic changes? (A good amount of time ago I did believe that the main purpose of the Open Source idea was to copy source code between projects, to avoid reinventing things. I was so wrong.) Bye, bearophile
Jun 22 2010
next sibling parent reply bearophile <bearophileHUGS lycos.com> writes:
Leandro Lucarella:
 but about 2), one of the main goals of LLVM was
 to have a less restrictive license than GPL, so copying GPL code is not
 an option for them.

Can't you copy it by something like 90%, enough to be able to call it different code (that's what I was referring with 'cosmetic changes')? Bye, bearophile
Jun 22 2010
next sibling parent reply BCS <none anon.com> writes:
Hello bearophile,

 Leandro Lucarella:
 
 but about 2), one of the main goals of LLVM was
 to have a less restrictive license than GPL, so copying GPL code is
 not
 an option for them.

different code (that's what I was referring with 'cosmetic changes')?

IIRC the only way to escape a GNU license is to do a cleanroom. If the file started under GNU, it will forever be GNU. -- ... <IXOYE><
Jun 22 2010
parent reply bearophile <bearophileHUGS lycos.com> writes:
Leandro Lucarella:
 Yes, I don't think "copying with 'cosmetic changes'" works, legally
 speaking. Otherwise everybody would be doing it.

If 10% of changes is not legally enough, they LLVM dev can copy it and then change the 15% of it or even 20%. There must exist a minimum amount of differences between two blocks of code that allows them to be legally considered different, otherwise GNU is worse than a software patent. Nick Sabalausky:
Plus, do we even know that this is what's holding up LLVM exceptions on
Windows?<

The main LLVM dev(s) are hired by Apple, that I presume is not so worried of windows too much. What they want is people to think LLVM is a bit multi-platform, so they can contribute to the project for free. I'll restart helping the LLVM project when it has gained some exceptions for Windows :-) Bye, bearophile
Jun 23 2010
next sibling parent Justin Johansson <no spam.com> writes:
bearophile wrote:
 Leandro Lucarella:
 Yes, I don't think "copying with 'cosmetic changes'" works, legally
 speaking. Otherwise everybody would be doing it.

If 10% of changes is not legally enough, they LLVM dev can copy it and then change the 15% of it or even 20%. There must exist a minimum amount of differences between two blocks of code that allows them to be legally considered different, otherwise GNU is worse than a software patent. Nick Sabalausky:
 Plus, do we even know that this is what's holding up LLVM exceptions on
Windows?<

The main LLVM dev(s) are hired by Apple, that I presume is not so worried of windows too much. What they want is people to think LLVM is a bit multi-platform, so they can contribute to the project for free. I'll restart helping the LLVM project when it has gained some exceptions for Windows :-) Bye, bearophile

Hear, hear. Sometimes the pendulum swings too far one way and then time becomes due for it to swing back the other way. Windows exception system (SEH - structured exception handling) does have some nice things about it which are tedious if not difficult on other platforms. It would be gracious of LLVM to acknowledge this. Cheers Justin Johansson
Jun 23 2010
prev sibling next sibling parent BCS <none anon.com> writes:
Hello bearophile,

 Leandro Lucarella:
 
 Yes, I don't think "copying with 'cosmetic changes'" works, legally
 speaking. Otherwise everybody would be doing it.
 

then change the 15% of it or even 20%. There must exist a minimum amount of differences between two blocks of code that allows them to be legally considered different, otherwise GNU is worse than a software patent.

The fact that you started with GNU code it the important thing: the original file is under GNU, so the file after the very first edit (one key stroke) is also under GNU and because it is, so is the file after the second edit, etc. etc. If you started with a blank file and ended up with something that (after ignoring formatting) was 50% similar to some GNU code, you might be able to get away with it as long as you've never looked at the other code, but I wouldn't bet on it. -- ... <IXOYE><
Jun 23 2010
prev sibling next sibling parent KennyTM~ <kennytm gmail.com> writes:
On Jun 23, 10 19:18, bearophile wrote:
 Leandro Lucarella:
 Yes, I don't think "copying with 'cosmetic changes'" works, legally
 speaking. Otherwise everybody would be doing it.

If 10% of changes is not legally enough, they LLVM dev can copy it and then change the 15% of it or even 20%. There must exist a minimum amount of differences between two blocks of code that allows them to be legally considered different, otherwise GNU is worse than a software patent.

The % doesn't matter. If your code is a "derivative work" of some GPL code, then your code must also be in GPL if you distribute it.
 Nick Sabalausky:
 Plus, do we even know that this is what's holding up LLVM exceptions on
Windows?<

The main LLVM dev(s) are hired by Apple, that I presume is not so worried of windows too much. What they want is people to think LLVM is a bit multi-platform, so they can contribute to the project for free. I'll restart helping the LLVM project when it has gained some exceptions for Windows :-) Bye, bearophile

Jun 23 2010
prev sibling next sibling parent "Nick Sabalausky" <a a.a> writes:
"bearophile" <bearophileHUGS lycos.com> wrote in message 
news:hvsqhj$ik$1 digitalmars.com...
 Leandro Lucarella:
 Yes, I don't think "copying with 'cosmetic changes'" works, legally
 speaking. Otherwise everybody would be doing it.

If 10% of changes is not legally enough, they LLVM dev can copy it and then change the 15% of it or even 20%. There must exist a minimum amount of differences between two blocks of code that allows them to be legally considered different, otherwise GNU is worse than a software patent.

Many people do consider the GPL evil.
Jun 23 2010
prev sibling parent Kagamin <spam here.lot> writes:
bearophile Wrote:

 Leandro Lucarella:
 Yes, I don't think "copying with 'cosmetic changes'" works, legally
 speaking. Otherwise everybody would be doing it.

If 10% of changes is not legally enough, they LLVM dev can copy it and then change the 15% of it or even 20%. There must exist a minimum amount of differences between two blocks of code that allows them to be legally considered different, otherwise GNU is worse than a software patent.

Jun 24 2010
prev sibling parent Leandro Lucarella <luca llucax.com.ar> writes:
BCS, el 23 de junio a las 02:09 me escribiste:
 Hello bearophile,
 
Leandro Lucarella:

but about 2), one of the main goals of LLVM was
to have a less restrictive license than GPL, so copying GPL code is
not
an option for them.

different code (that's what I was referring with 'cosmetic changes')?

IIRC the only way to escape a GNU license is to do a cleanroom. If the file started under GNU, it will forever be GNU.

Yes, I don't think "copying with 'cosmetic changes'" works, legally speaking. Otherwise everybody would be doing it. -- Leandro Lucarella (AKA luca) http://llucax.com.ar/ ---------------------------------------------------------------------- GPG Key: 5F5A8D05 (F8CD F9A7 BF00 5431 4145 104C 949E BFB6 5F5A 8D05) ---------------------------------------------------------------------- El techo de mi cuarto lleno de cometas
Jun 22 2010
prev sibling next sibling parent reply BCS <none anon.com> writes:
Hello bearophile,

 Robert Jacques:
 
 The patent seems to be Borlands's:
 USPTO patent #5,628,016 Patent held by Borland on compiler support
 for SEH.
 From a Wine wiki page:
 http://wiki.winehq.org/CompilerExceptionSupport
 It does seem to expire on June 15, 2014, though and I assume
 DigitalMars  has a license, so a LLVM fork is not unreasonable.
 

1) Do you know how they do this? Do they have a license? If they have a licence why don't LLVM people too have it?

The patent holder has refused licenses to all OSS projects. What GCC does is use a different system (something to do with tables). The patent is strictly for SEH. -- ... <IXOYE><
Jun 22 2010
parent reply "Nick Sabalausky" <a a.a> writes:
"BCS" <none anon.com> wrote in message 
news:a6268ff1581a8cce05541b41e04 news.digitalmars.com...
 Hello bearophile,

 Robert Jacques:

 The patent seems to be Borlands's:
 USPTO patent #5,628,016 Patent held by Borland on compiler support
 for SEH.
 From a Wine wiki page:
 http://wiki.winehq.org/CompilerExceptionSupport
 It does seem to expire on June 15, 2014, though and I assume
 DigitalMars  has a license, so a LLVM fork is not unreasonable.

1) Do you know how they do this? Do they have a license? If they have a licence why don't LLVM people too have it?

The patent holder has refused licenses to all OSS projects. What GCC does is use a different system (something to do with tables). The patent is strictly for SEH.

So can't LLVM just take the same approach? Also, accoroding to http://www.microsoft.com/msj/0197/Exception/Exception.aspx (One of the links on the page from Robert above), SEH is a service provided by Windows. So wouldn't MS be the only one that would need a license? (I'm probably just misunderstanding something here.) Plus, do we even know that this is what's holding up LLVM exceptions on Windows?
Jun 22 2010
next sibling parent BCS <none anon.com> writes:
Hello Nick,

 "BCS" <none anon.com> wrote in message
 news:a6268ff1581a8cce05541b41e04 news.digitalmars.com...
 
 Hello bearophile,
 
 Robert Jacques:
 
 The patent seems to be Borlands's:
 USPTO patent #5,628,016 Patent held by Borland on compiler support
 for SEH.
 From a Wine wiki page:
 http://wiki.winehq.org/CompilerExceptionSupport
 It does seem to expire on June 15, 2014, though and I assume
 DigitalMars  has a license, so a LLVM fork is not unreasonable.

1) Do you know how they do this? Do they have a license? If they have a licence why don't LLVM people too have it?

does is use a different system (something to do with tables). The patent is strictly for SEH.

Also, accoroding to http://www.microsoft.com/msj/0197/Exception/Exception.aspx (One of the links on the page from Robert above), SEH is a service provided by Windows. So wouldn't MS be the only one that would need a license? (I'm probably just misunderstanding something here.)

The title of the patent leads me to believe that it covers compilers that generate code that uses SEH.
 
 Plus, do we even know that this is what's holding up LLVM exceptions
 on Windows?

I've heard from someone who would know that the patent is the reason SEH isn't in LLVM. I also have it from some (different someone) that LLVM should in theory have setjump/longjump exception handling under windows but they didn't even venture a guess if it actually worked. If it doesn't and if LDC would use it if it were fixed I'd be interested in at least looking into fixing it (LDC people???). -- ... <IXOYE><
Jun 22 2010
prev sibling parent Todd VanderVeen <TDVanderVeen gmail.com> writes:
That's funny. I read you original answer and  laughed. It was too true!
Jun 23 2010
prev sibling next sibling parent Leandro Lucarella <luca llucax.com.ar> writes:
Nick Sabalausky, el 22 de junio a las 22:35 me escribiste:
 "BCS" <none anon.com> wrote in message 
 news:a6268ff1581a8cce05541b41e04 news.digitalmars.com...
 Hello bearophile,

 Robert Jacques:

 The patent seems to be Borlands's:
 USPTO patent #5,628,016 Patent held by Borland on compiler support
 for SEH.
 From a Wine wiki page:
 http://wiki.winehq.org/CompilerExceptionSupport
 It does seem to expire on June 15, 2014, though and I assume
 DigitalMars  has a license, so a LLVM fork is not unreasonable.

1) Do you know how they do this? Do they have a license? If they have a licence why don't LLVM people too have it?

The patent holder has refused licenses to all OSS projects. What GCC does is use a different system (something to do with tables). The patent is strictly for SEH.

So can't LLVM just take the same approach? Also, accoroding to http://www.microsoft.com/msj/0197/Exception/Exception.aspx (One of the links on the page from Robert above), SEH is a service provided by Windows. So wouldn't MS be the only one that would need a license? (I'm probably just misunderstanding something here.) Plus, do we even know that this is what's holding up LLVM exceptions on Windows?

I guess the best way to get answers is to ask in the LLVM mailing list, I think here you'll only find more answers =) -- Leandro Lucarella (AKA luca) http://llucax.com.ar/ ---------------------------------------------------------------------- GPG Key: 5F5A8D05 (F8CD F9A7 BF00 5431 4145 104C 949E BFB6 5F5A 8D05) ---------------------------------------------------------------------- Lo último que hay que pensar es que se desalinea la memoria Hay que priorizar como causa la idiotez propia Ya lo tengo asumido -- Pablete, filósofo contemporáneo desconocido
Jun 22 2010
prev sibling next sibling parent Leandro Lucarella <luca llucax.com.ar> writes:
Leandro Lucarella, el 23 de junio a las 00:31 me escribiste:
 Nick Sabalausky, el 22 de junio a las 22:35 me escribiste:
 "BCS" <none anon.com> wrote in message 
 news:a6268ff1581a8cce05541b41e04 news.digitalmars.com...
 Hello bearophile,

 Robert Jacques:

 The patent seems to be Borlands's:
 USPTO patent #5,628,016 Patent held by Borland on compiler support
 for SEH.
 From a Wine wiki page:
 http://wiki.winehq.org/CompilerExceptionSupport
 It does seem to expire on June 15, 2014, though and I assume
 DigitalMars  has a license, so a LLVM fork is not unreasonable.

1) Do you know how they do this? Do they have a license? If they have a licence why don't LLVM people too have it?

The patent holder has refused licenses to all OSS projects. What GCC does is use a different system (something to do with tables). The patent is strictly for SEH.

So can't LLVM just take the same approach? Also, accoroding to http://www.microsoft.com/msj/0197/Exception/Exception.aspx (One of the links on the page from Robert above), SEH is a service provided by Windows. So wouldn't MS be the only one that would need a license? (I'm probably just misunderstanding something here.) Plus, do we even know that this is what's holding up LLVM exceptions on Windows?

I guess the best way to get answers is to ask in the LLVM mailing list, I think here you'll only find more answers =)

Stupid! Stupid! s/more answers/more questions/ -- Leandro Lucarella (AKA luca) http://llucax.com.ar/ ---------------------------------------------------------------------- GPG Key: 5F5A8D05 (F8CD F9A7 BF00 5431 4145 104C 949E BFB6 5F5A 8D05) ---------------------------------------------------------------------- Can you stand up? I do believe it's working, good. That'll keep you going through the show Come on it's time to go.
Jun 22 2010
prev sibling parent reply =?UTF-8?B?IkrDqXLDtG1lIE0uIEJlcmdlciI=?= <jeberger free.fr> writes:
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

bearophile wrote:
 Robert Jacques:
 The patent seems to be Borlands's:
 USPTO patent #5,628,016 Patent held by Borland on compiler support for=


  From a Wine wiki page: http://wiki.winehq.org/CompilerExceptionSuppor=


 It does seem to expire on June 15, 2014, though and I assume DigitalMa=


 has a license, so a LLVM fork is not unreasonable.

On Windows G++ supports exceptions. I have two questions: 1) Do you know how they do this? Do they have a license? If they have a=

Gcc has two ways to do this: * Using setjump/longjump. This works across foreign DLL calls, but incurs a small performance penalty even if no exception is thrown (setjmp needs to be called for each stack frame which will require cleanup in case of exception); * Embedding dwarf information in the executable to allow stack unwinding. This only works if all the stack frames where an exception may occur where compiled with gcc (i.e you may call foreign DLLs, but if you give them a callback then this callback may not throw). This has absolutely no performance penalty so long as no exception is thrown. Neither approach is compatible with MS exception handling, so you can't call an MS C++ DLL and catch the exceptions it throws, and if you call a DLL and give it a callback and your callback throws then the cleanup code in the DLL won't be run (and vice versa of course). SEH would allow this to work.
 2) Why isn't LLVM just copying that part of the GCC code? If a true cop=

es? (A good amount of time ago I did believe that the main purpose of the= Open Source idea was to copy source code between projects, to avoid rein= venting things. I was so wrong.)
=20

LLVM devs are on MacOS. Posix platforms are close enough to MacOS that they can get by with less porting effort (plus they probably have more motivated devs than Windows), so they are not too far behind, but Windows is another matter. Jerome --=20 mailto:jeberger free.fr http://jeberger.free.fr Jabber: jeberger jabber.fr
Jun 23 2010
parent reply bearophile <bearophileHUGS lycos.com> writes:
Thank you Jerome and all the people that have answered me, I was ignorant about
GNU license.

 if you call a DLL and give it a callback and your callback throws then
 the cleanup code in the DLL won't be run (and vice versa of course).
 SEH would allow this to work.

If someone writes a compiler/language that allows programs to be ported with no problems from Windows to other nonwindows systems, this may damage Windows a little (but isn't Mono able to do this with C#2 programs?). But it's economically advantageous for Microsoft to make it easy for people to create new compilers and languages for Windows that work well with other Windows programs. So in my opinion having a good Clang++ on Windows is good for the economic well-being of Windows. They can grant LLVM a free licence to use Windows-style exceptions. Bye, bearophile
Jun 23 2010
next sibling parent reply KennyTM~ <kennytm gmail.com> writes:
On Jun 24, 10 03:57, bearophile wrote:
 Thank you Jerome and all the people that have answered me, I was ignorant
about GNU license.

 if you call a DLL and give it a callback and your callback throws then
 the cleanup code in the DLL won't be run (and vice versa of course).
 SEH would allow this to work.

If someone writes a compiler/language that allows programs to be ported with no problems from Windows to other nonwindows systems, this may damage Windows a little (but isn't Mono able to do this with C#2 programs?). But it's economically advantageous for Microsoft to make it easy for people to create new compilers and languages for Windows that work well with other Windows programs. So in my opinion having a good Clang++ on Windows is good for the economic well-being of Windows. They can grant LLVM a free licence to use Windows-style exceptions. Bye, bearophile

Why should Microsoft do that instead of promoting Visual C++? ;)
Jun 23 2010
next sibling parent reply Don <nospam nospam.com> writes:
KennyTM~ wrote:
 On Jun 24, 10 03:57, bearophile wrote:
 Thank you Jerome and all the people that have answered me, I was 
 ignorant about GNU license.

 if you call a DLL and give it a callback and your callback throws then
 the cleanup code in the DLL won't be run (and vice versa of course).
 SEH would allow this to work.

If someone writes a compiler/language that allows programs to be ported with no problems from Windows to other nonwindows systems, this may damage Windows a little (but isn't Mono able to do this with C#2 programs?). But it's economically advantageous for Microsoft to make it easy for people to create new compilers and languages for Windows that work well with other Windows programs. So in my opinion having a good Clang++ on Windows is good for the economic well-being of Windows. They can grant LLVM a free licence to use Windows-style exceptions. Bye, bearophile

Why should Microsoft do that instead of promoting Visual C++? ;)

Because there's no money in compilers anymore.
Jun 23 2010
parent BCS <none anon.com> writes:
Hello Don,

 KennyTM~ wrote:
 
 Why should Microsoft do that instead of promoting Visual C++? ;)
 


Very true. Or in languages for that matter. But there is huge money in tools. -- ... <IXOYE><
Jun 23 2010
prev sibling parent reply =?UTF-8?B?IkrDqXLDtG1lIE0uIEJlcmdlciI=?= <jeberger free.fr> writes:
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

KennyTM~ wrote:
 On Jun 24, 10 03:57, bearophile wrote:
 Thank you Jerome and all the people that have answered me, I was
 ignorant about GNU license.

 if you call a DLL and give it a callback and your callback throws the=



 the cleanup code in the DLL won't be run (and vice versa of course).
 SEH would allow this to work.

If someone writes a compiler/language that allows programs to be ported with no problems from Windows to other nonwindows systems, this=


 may damage Windows a little (but isn't Mono able to do this with C#2
 programs?).

 But it's economically advantageous for Microsoft to make it easy for
 people to create new compilers and languages for Windows that work
 well with other Windows programs. So in my opinion having a good
 Clang++ on Windows is good for the economic well-being of Windows.
 They can grant LLVM a free licence to use Windows-style exceptions.

 Bye,
 bearophile

Why should Microsoft do that instead of promoting Visual C++? ;)

Because they're giving away Visual C++ for free anyway? Jerome --=20 mailto:jeberger free.fr http://jeberger.free.fr Jabber: jeberger jabber.fr
Jun 23 2010
parent BCS <none anon.com> writes:
Hello Jrme,

 KennyTM~ wrote:
 
 On Jun 24, 10 03:57, bearophile wrote:
 
 Thank you Jerome and all the people that have answered me, I was
 ignorant about GNU license.
 
 if you call a DLL and give it a callback and your callback throws
 then the cleanup code in the DLL won't be run (and vice versa of
 course). SEH would allow this to work.
 

ported with no problems from Windows to other nonwindows systems, this may damage Windows a little (but isn't Mono able to do this with C#2 programs?). But it's economically advantageous for Microsoft to make it easy for people to create new compilers and languages for Windows that work well with other Windows programs. So in my opinion having a good Clang++ on Windows is good for the economic well-being of Windows. They can grant LLVM a free licence to use Windows-style exceptions. Bye, bearophile



Only to the people they wouldn't get money out of anyway. Anyone who /could/ matter a gnat's fart in a hurricane to MS's bottom line will want more than the free offering gives. -- ... <IXOYE><
Jun 23 2010
prev sibling next sibling parent "Nick Sabalausky" <a a.a> writes:
"bearophile" <bearophileHUGS lycos.com> wrote in message 
news:hvtovg$2m07$1 digitalmars.com...
 Thank you Jerome and all the people that have answered me, I was ignorant 
 about GNU license.

 if you call a DLL and give it a callback and your callback throws then
 the cleanup code in the DLL won't be run (and vice versa of course).
 SEH would allow this to work.

If someone writes a compiler/language that allows programs to be ported with no problems from Windows to other nonwindows systems, this may damage Windows a little (but isn't Mono able to do this with C#2 programs?). But it's economically advantageous for Microsoft to make it easy for people to create new compilers and languages for Windows that work well with other Windows programs. So in my opinion having a good Clang++ on Windows is good for the economic well-being of Windows. They can grant LLVM a free licence to use Windows-style exceptions.

Unfortunately, that's never gonna happen. They prefer to use their patents to extort companies that use OSS code: http://www.computerworlduk.com/toolbox/open-source/blogs/index.cfm?entryid=1953&blogid=14 http://news.cnet.com/8301-13860_3-10206988-56.html ------------------------------- Not sent from an iPhone.
Jun 23 2010
prev sibling parent BCS <none anon.com> writes:
Hello bearophile,


 But it's economically advantageous for Microsoft to make it easy for
 people to create new compilers and languages for Windows that work
 well with other Windows programs. So in my opinion having a good
 Clang++ on Windows is good for the economic well-being of Windows.
 They can grant LLVM a free licence to use Windows-style exceptions.

It should be safe to assume that most windows programs (by how many are running) are compiler with MSVC and at $800 to $5000 (and up IIRC) a pop why should they do anything to help the competition? Seriously, I suspect that GCC, LLVM, etc. are literally irrelevant to how much MS makes off Windows. -- ... <IXOYE><
Jun 23 2010
prev sibling next sibling parent "Robert Jacques" <sandford jhu.edu> writes:
On Tue, 22 Jun 2010 16:47:14 -0400, BCS <none anon.com> wrote:

 Hello Robert,

 On Mon, 21 Jun 2010 23:55:48 -0400, BCS <none anon.com> wrote:

 Hello Leandro,

 Nick Sabalausky, el 21 de junio a las 13:40 me escribiste:

 "Eldar Insafutdinov" <e.insafutdinov gmail.com> wrote in message
 news:hvo49k$1uk3$1 digitalmars.com...

 In the end, Windows is the most popular
 OS despite our personal preferences, and it's worth spending some
 time for
 it.


Windows should give some love to LLVM =)

little in compiler work but if the problems could be attacked without to much ramp-up I'd be interested in looking into them.

exception handling to LLVM.

After a little digging it seems that LLVM legally CAN'T add SEH as MS has it under patent. I'm still digging to figure out how it could be patented without making SEH an irrelevant technology.

The patent seems to be Borlands's: USPTO patent #5,628,016 Patent held by Borland on compiler support for SEH. From a Wine wiki page: http://wiki.winehq.org/CompilerExceptionSupport It does seem to expire on June 15, 2014, though and I assume DigitalMars has a license, so a LLVM fork is not unreasonable.
Jun 22 2010
prev sibling parent Leandro Lucarella <luca llucax.com.ar> writes:
bearophile, el 22 de junio a las 19:25 me escribiste:
 Robert Jacques:
 The patent seems to be Borlands's:
 USPTO patent #5,628,016 Patent held by Borland on compiler support for SEH.
  From a Wine wiki page: http://wiki.winehq.org/CompilerExceptionSupport
 
 It does seem to expire on June 15, 2014, though and I assume DigitalMars  
 has a license, so a LLVM fork is not unreasonable.

On Windows G++ supports exceptions. I have two questions: 1) Do you know how they do this? Do they have a license? If they have a licence why don't LLVM people too have it? 2) Why isn't LLVM just copying that part of the GCC code? If a true copy is not possible, why aren't copying the code with enough cosmetic changes? (A good amount of time ago I did believe that the main purpose of the Open Source idea was to copy source code between projects, to avoid reinventing things. I was so wrong.)

I don't know about 1), but about 2), one of the main goals of LLVM was to have a less restrictive license than GPL, so copying GPL code is not an option for them. -- Leandro Lucarella (AKA luca) http://llucax.com.ar/ ---------------------------------------------------------------------- GPG Key: 5F5A8D05 (F8CD F9A7 BF00 5431 4145 104C 949E BFB6 5F5A 8D05) ---------------------------------------------------------------------- HACIA NEUQUEN: EL JUEVES SALDRA CARAVANA CON PERROS DESDE CAPITAL EN APOYO AL CACHORRO CONDENADO A MUERTE -- Crónica TV
Jun 22 2010
prev sibling parent reply Leandro Lucarella <luca llucax.com.ar> writes:
Kagamin, el 22 de junio a las 07:01 me escribiste:
 Robert Jacques Wrote:
 
 The main issue (as I understand it) is adding windows style structured  
 exception handling to LLVM.

C++ compiles for me. Or are there some other issues?

LDC compiles too, but it doesn't support exceptions. I guess is the same with C++. -- Leandro Lucarella (AKA luca) http://llucax.com.ar/ ---------------------------------------------------------------------- GPG Key: 5F5A8D05 (F8CD F9A7 BF00 5431 4145 104C 949E BFB6 5F5A 8D05) ---------------------------------------------------------------------- 'It's not you, it's me....'? You're giving me the 'It's not you, it's me' routine? I invented 'It's not you, it's me.' Nobody tells me it's them, not me. If it's anybody, it's me. -- George Constanza
Jun 22 2010
parent BCS <none anon.com> writes:
Hello Leandro,

 Kagamin, el 22 de junio a las 07:01 me escribiste:
 
 Robert Jacques Wrote:
 
 The main issue (as I understand it) is adding windows style
 structured  exception handling to LLVM.
 


same with C++.

Why doesn't LLVM support other forms of exceptions? GCC does. -- ... <IXOYE><
Jun 22 2010
prev sibling parent Long Chang <changedalone gmail.com> writes:
--001636c9351844eb6d0489912b5e
Content-Type: text/plain; charset=UTF-8

In windows if you want use some lib that is not provide dynamic dll support,
you need compile it with dmc. In this case your need deal a lot problem with
lack of c head file . if there is a vc++ version backend will be big help
for a lot of people who is not familiarity with c/c++ .



2010/6/22 Eldar Insafutdinov <e.insafutdinov gmail.com>

 == Quote from dsimcha (dsimcha yahoo.com)'s article
 What is the long-term plan for the current DMD backend?  I've noticed the
 first steps towards 64-bit support were just checked in today (excitement

 the extreme).  However, the backend is under such a restrictive license

 I understand Walter is not free to change) that it has a "bus factor" of

 If Walter were to stop maintaining it, noone else would be able to, if I
 understand the licensing issues correctly.
 Is there a chance of these licensing issues being cleared up so that the
 backend can be released under a more permissive license?  If not, while I
 understand Walter's decision to use a backend he was familiar with in the
 beginning, it seems like we should abandon such a heavily encumbered

 now that it needs serious work.

Hi I agree with what Sean says. Even more, DMD backend is good for development process, because it is very fast as opposed to more popular ones like llvm or gcc. What really worries me is what is going to happen on Windows. We have the burden which is old file format and optlink. There are still big problems with the linker, it has random problems on big projects, building them with debug info is even more problematic. As far as I understood that linker is being rewritten to C, but the process is very slow. It may take years to complete the port, and then to make it 64bit capable, isn't it? All existing problems would be propagated further. I would suggest(again and again) to add a new Windows backend targeting MinGW or MSVC toolchain. It should not necessarily replace the existing one, but people would at least have freedom and there wouldn't be situation that you are stuck in development when linker fails. Also those toolchain support 64bit, so it is another advantage. For those who still wants digital mars toolchain - there will be an old one. Remembering that it took Walter about 6 weeks to implement MacOS backend, that doesn't seem too bad. In the end, Windows is the most popular OS despite our personal preferences, and it's worth spending some time for it. Cheers

--001636c9351844eb6d0489912b5e Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable In windows if you want use some lib that is not provide dynamic dll support= , you need compile it with dmc. In this case your need deal a lot problem w= ith lack of c head file . if there is a vc++ version backend will be big he= lp for a lot of people who is not familiarity with c/c++ .<br> <br><br><br><div class=3D"gmail_quote">2010/6/22 Eldar Insafutdinov <span d= ir=3D"ltr">&lt;<a href=3D"mailto:e.insafutdinov gmail.com">e.insafutdinov g= mail.com</a>&gt;</span><br><blockquote class=3D"gmail_quote" style=3D"margi= n: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-le= ft: 1ex;"> =3D=3D Quote from dsimcha (<a href=3D"mailto:dsimcha yahoo.com">dsimcha yah= oo.com</a>)&#39;s article<br> <div><div></div><div class=3D"h5">&gt; What is the long-term plan for the c= urrent DMD backend? =C2=A0I&#39;ve noticed the<br> &gt; first steps towards 64-bit support were just checked in today (excitem= ent to<br> &gt; the extreme). =C2=A0However, the backend is under such a restrictive l= icense (which<br> &gt; I understand Walter is not free to change) that it has a &quot;bus fac= tor&quot; of 1.<br> &gt; If Walter were to stop maintaining it, noone else would be able to, if= I<br> &gt; understand the licensing issues correctly.<br> &gt; Is there a chance of these licensing issues being cleared up so that t= he<br> &gt; backend can be released under a more permissive license? =C2=A0If not,= while I<br> &gt; understand Walter&#39;s decision to use a backend he was familiar with= in the<br> &gt; beginning, it seems like we should abandon such a heavily encumbered b= ackend<br> &gt; now that it needs serious work.<br> <br> </div></div>Hi<br> <br> I agree with what Sean says. Even more, DMD backend is good for development= <br> process, because it is very fast as opposed to more popular ones like llvm = or gcc.<br> What really worries me is what is going to happen on Windows. We have the b= urden<br> which is old file format and optlink. There are still big problems with the= <br> linker, it has random problems on big projects, building them with debug in= fo is<br> even more problematic. As far as I understood that linker is being rewritte= n to C,<br> but the process is very slow. It may take years to complete the port, and t= hen to<br> make it 64bit capable, isn&#39;t it? All existing problems would be propaga= ted<br> further. I would suggest(again and again) to add a new Windows backend targ= eting<br> MinGW or MSVC toolchain. It should not necessarily replace the existing one= , but<br> people would at least have freedom and there wouldn&#39;t be situation that= you are<br> stuck in development when linker fails. Also those toolchain support 64bit,= so it<br> is another advantage. For those who still wants digital mars toolchain - th= ere<br> will be an old one. Remembering that it took Walter about 6 weeks to implem= ent<br> MacOS backend, that doesn&#39;t seem too bad. In the end, Windows is the mo= st popular<br> OS despite our personal preferences, and it&#39;s worth spending some time = for it.<br> <br> Cheers<br> </blockquote></div><br> --001636c9351844eb6d0489912b5e--
Jun 21 2010