I've noticed that Sean has recently added the core.demangle module to druntime.  Does this mean we can deprecate std.demangle?  I've never used it myself, but I seem to remember people saying on the NG that it is pretty outdated.

-Lars

On 10 sep 2010, at 10:12, Lars Tandle Kyllingstad wrote:

> I've noticed that Sean has recently added the core.demangle module to druntime.  Does this mean we can deprecate std.demangle?  I've never used it myself, but I seem to remember people saying on the NG that it is pretty outdated.
> 
> -Lars
> 
> _______________________________________________
> phobos mailing list
> phobos at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/phobos


I've used the demangler and can verify that the is outdated. These are the bugs I encountered:

std.demangle incorrectly handles template floating point numbers http://d.puremagic.com/issues/show_bug.cgi?id=4323

std.demangle doesn't parse ref, pure, nothrow http://d.puremagic.com/issues/show_bug.cgi?id=3334

I've not used the new demangler in druntime but at least I has code for demangling the function types mentioned in bug 3334.

-- 
/Jacob Carlborg

I wasn't sure whether to fix std.demangle now that core.demangle works, or to replace/deprecate it.  At the time I just needed something in druntime and I didn't like how std.demangle did everything via string ops. What do you all think?

Sent from my iPhone

On Sep 10, 2010, at 1:12 AM, Lars Tandle Kyllingstad <lars at kyllingen.net> wrote:

> I've noticed that Sean has recently added the core.demangle module to druntime.  Does this mean we can deprecate std.demangle?  I've never used it myself, but I seem to remember people saying on the NG that it is pretty outdated.
> 
> -Lars
> 
> _______________________________________________
> phobos mailing list
> phobos at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/phobos

Seems unnecessary to have two demanglers and since the one in Phobos doesn't work correctly I suggest it should be removed.

On 10 sep 2010, at 16:01, Sean Kelly wrote:

> I wasn't sure whether to fix std.demangle now that core.demangle works, or to replace/deprecate it.  At the time I just needed something in druntime and I didn't like how std.demangle did everything via string ops. What do you all think?
> 
> Sent from my iPhone
> 
> On Sep 10, 2010, at 1:12 AM, Lars Tandle Kyllingstad <lars at kyllingen.net> wrote:
> 
>> I've noticed that Sean has recently added the core.demangle module to druntime.  Does this mean we can deprecate std.demangle?  I've never used it myself, but I seem to remember people saying on the NG that it is pretty outdated.
>> 
>> -Lars
>> 
>> _______________________________________________
>> phobos mailing list
>> phobos at puremagic.com
>> http://lists.puremagic.com/mailman/listinfo/phobos
> _______________________________________________
> phobos mailing list
> phobos at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/phobos

-- 
/Jacob Carlborg

Remove std.demangle and continue maintaining core.demangle.

Andrei

On 9/10/10 9:01 CDT, Sean Kelly wrote:
> I wasn't sure whether to fix std.demangle now that core.demangle works, or to replace/deprecate it.  At the time I just needed something in druntime and I didn't like how std.demangle did everything via string ops. What do you all think?
>
> Sent from my iPhone
>
> On Sep 10, 2010, at 1:12 AM, Lars Tandle Kyllingstad<lars at kyllingen.net>  wrote:
>
>> I've noticed that Sean has recently added the core.demangle module to druntime.  Does this mean we can deprecate std.demangle?  I've never used it myself, but I seem to remember people saying on the NG that it is pretty outdated.
>>
>> -Lars
>>
>> _______________________________________________
>> phobos mailing list
>> phobos at puremagic.com
>> http://lists.puremagic.com/mailman/listinfo/phobos
> _______________________________________________
> phobos mailing list
> phobos at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/phobos

I tried to use core.demangle to print human-readable profiling reports and it still seems to fail horribly on some symbols.  The un-demanglable symbols seem to  be really complicated template instantiations, like randomShuffle!(chain!(... .  IIRC there's some fundamental limitation where once a symbol gets huge DMD relies on hashing, so the mangling no longer has an inverse.  Is this true, or is it worth spending some time trying to create a decent test case?

On Fri, Sep 10, 2010 at 10:14 AM, Andrei Alexandrescu <andrei at erdani.com>wrote:

> Remove std.demangle and continue maintaining core.demangle.
>
> Andrei
>
>
> On 9/10/10 9:01 CDT, Sean Kelly wrote:
>
>> I wasn't sure whether to fix std.demangle now that core.demangle works, or to replace/deprecate it.  At the time I just needed something in druntime and I didn't like how std.demangle did everything via string ops. What do you all think?
>>
>> Sent from my iPhone
>>
>> On Sep 10, 2010, at 1:12 AM, Lars Tandle Kyllingstad<lars at kyllingen.net>
>>  wrote:
>>
>>  I've noticed that Sean has recently added the core.demangle module to
>>> druntime.  Does this mean we can deprecate std.demangle?  I've never used it myself, but I seem to remember people saying on the NG that it is pretty outdated.
>>>
>>> -Lars
>>>
>>> _______________________________________________
>>> phobos mailing list
>>> phobos at puremagic.com
>>> http://lists.puremagic.com/mailman/listinfo/phobos
>>>
>> _______________________________________________
>> phobos mailing list
>> phobos at puremagic.com
>> http://lists.puremagic.com/mailman/listinfo/phobos
>>
> _______________________________________________
> phobos mailing list
> phobos at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/phobos
>
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On Fri, Sep 10, 2010 at 8:37 PM, David Simcha <dsimcha at gmail.com> wrote:
> I tried to use core.demangle to print human-readable profiling reports and it still seems to fail horribly on some symbols.? The un-demanglable symbols seem to? be really complicated template instantiations, like randomShuffle!(chain!(... .? IIRC there's some fundamental limitation where once a symbol gets huge DMD relies on hashing, so the mangling no longer has an inverse.? Is this true, or is it worth spending some time trying to create a decent test case?
>

The following issue I reported over a year ago might help: http://d.puremagic.com/issues/show_bug.cgi?id=2238

There is also a small test case.

I don't think the compression is mentioned in the ABI, so core.demangle won't handle it correctly.  I'll take a look at the DMD source and see what can be done.  Hopefully there's some easy way for a parser to recognize that a symbol is compressed.

On Sep 10, 2010, at 9:37 AM, David Simcha wrote:

> I tried to use core.demangle to print human-readable profiling reports and it still seems to fail horribly on some symbols.  The un-demanglable symbols seem to  be really complicated template instantiations, like randomShuffle!(chain!(... .  IIRC there's some fundamental limitation where once a symbol gets huge DMD relies on hashing, so the mangling no longer has an inverse.  Is this true, or is it worth spending some time trying to create a decent test case?
> 
> On Fri, Sep 10, 2010 at 10:14 AM, Andrei Alexandrescu <andrei at erdani.com> wrote: Remove std.demangle and continue maintaining core.demangle.
> 
> Andrei
> 
> 
> On 9/10/10 9:01 CDT, Sean Kelly wrote:
> I wasn't sure whether to fix std.demangle now that core.demangle works, or to replace/deprecate it.  At the time I just needed something in druntime and I didn't like how std.demangle did everything via string ops. What do you all think?
> 
> Sent from my iPhone
> 
> On Sep 10, 2010, at 1:12 AM, Lars Tandle Kyllingstad<lars at kyllingen.net>  wrote:
> 
> I've noticed that Sean has recently added the core.demangle module to druntime.  Does this mean we can deprecate std.demangle?  I've never used it myself, but I seem to remember people saying on the NG that it is pretty outdated.
> 
> -Lars
> 
> _______________________________________________
> phobos mailing list
> phobos at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/phobos
> _______________________________________________
> phobos mailing list
> phobos at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/phobos
> _______________________________________________
> phobos mailing list
> phobos at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/phobos
> 
> _______________________________________________
> phobos mailing list
> phobos at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/phobos

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David Simcha wrote:
> I tried to use core.demangle to print human-readable profiling reports and it still seems to fail horribly on some symbols.  The un-demanglable symbols seem to  be really complicated template instantiations, like randomShuffle!(chain!(... .  IIRC there's some fundamental limitation where once a symbol gets huge DMD relies on hashing, so the mangling no longer has an inverse.  Is this true, or is it worth spending some time trying to create a decent test case?

If a symbol is to large for the object file format, it gets compressed. If that is to large, a hash (MD5?) is taken (I would assume of the uncompressed symbol). OTOH, anything that is that long is going to be ugly even if you could de-mangle it.

>
> On Fri, Sep 10, 2010 at 10:14 AM, Andrei Alexandrescu <andrei at erdani.com <mailto:andrei at erdani.com>> wrote:
>
>     Remove std.demangle and continue maintaining core.demangle.
>
>     Andrei
>
>
>     On 9/10/10 9:01 CDT, Sean Kelly wrote:
>
>         I wasn't sure whether to fix std.demangle now that
>         core.demangle works, or to replace/deprecate it.  At the time
>         I just needed something in druntime and I didn't like how
>         std.demangle did everything via string ops. What do you all think?
>
>         Sent from my iPhone
>
>         On Sep 10, 2010, at 1:12 AM, Lars Tandle
>         Kyllingstad<lars at kyllingen.net <mailto:lars at kyllingen.net>>
>          wrote:
>
>             I've noticed that Sean has recently added the
>             core.demangle module to
>             druntime.  Does this mean we can deprecate std.demangle?
>              I've never
>             used it myself, but I seem to remember people saying on
>             the NG that it
>             is pretty outdated.
>
>             -Lars
>
>             _______________________________________________
>             phobos mailing list
>             phobos at puremagic.com <mailto:phobos at puremagic.com>
>             http://lists.puremagic.com/mailman/listinfo/phobos
>
>         _______________________________________________
>         phobos mailing list
>         phobos at puremagic.com <mailto:phobos at puremagic.com>
>         http://lists.puremagic.com/mailman/listinfo/phobos
>
>     _______________________________________________
>     phobos mailing list
>     phobos at puremagic.com <mailto:phobos at puremagic.com>
>     http://lists.puremagic.com/mailman/listinfo/phobos
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> phobos mailing list
> phobos at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/phobos

On Friday 10 September 2010 19:02:53 Benjamin Shropshire wrote:
> OTOH, anything that is that long is going to be
> ugly even if you could de-mangle it.

True, but templates can get pretty long and ugly (even if they're not quite as bad in D since you don't have allocators and whatnot), and sometimes you need to see what they look like. Now, for a stack trace, you probably don't nee to see what the _exact_ type is once it gets that long and nasty - you can probably figure out which function is meant just fine - but for other uses, it could be a bit annoying to not have long template types completely demangled.

- Jonathan M Davis