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digitalmars.D.bugs - [Issue 929] New: Resizing array of associative arrays (uint[char[]][]) causes infinite loop / hang

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=929

           Summary: Resizing array of associative arrays (uint[char[]][])
                    causes infinite loop / hang
           Product: D
           Version: 1.004
          Platform: PC
        OS/Version: Windows
            Status: NEW
          Severity: major
          Priority: P2
         Component: DMD
        AssignedTo: bugzilla digitalmars.com
        ReportedBy: nick.atamas gmail.com


The following code produces an infinite loop. When executed "before" is printed
but "after" is never reached.

import std.stdio;
int main()
{
        uint[char[]][] fractal;
        writefln("before"); 
        fractal.length = 10;
        writefln("after"); 

        return 0;
}


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Feb 03 2007
next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=929


fvbommel wxs.nl changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |accepts-invalid





http://www.digitalmars.com/d/arrays.html#associative (under "Properties"):
.length         Returns number of values in the associative array. Unlike for
dynamic arrays, it is read-only.

So this shouldn't even compile...


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Feb 04 2007
prev sibling next sibling parent d-bugmail puremagic.com writes:
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torhu yahoo.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |torhu yahoo.com
           Keywords|accepts-invalid             |







 http://www.digitalmars.com/d/arrays.html#associative (under "Properties"):
 .length         Returns number of values in the associative array. Unlike for
 dynamic arrays, it is read-only.
 
 So this shouldn't even compile...
 


uint[char[]][] fractal;

fractal is a dynamic array, so length is not read-only.


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Feb 04 2007
prev sibling next sibling parent d-bugmail puremagic.com writes:
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 uint[char[]][] fractal;
 
 fractal is a dynamic array, so length is not read-only.


Ah, I missed the last brackets. Sorry about that.


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Feb 04 2007
prev sibling next sibling parent d-bugmail puremagic.com writes:
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This worked just fine in DMD1.0. It was broken recently.

I am currently using a workaround - encapsulating uint[char[]] into a class and
making an array of those.


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Feb 04 2007
prev sibling next sibling parent d-bugmail puremagic.com writes:
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thomas-dloop kuehne.cn changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         OS/Version|Windows                     |All





Added to DStress as
http://dstress.kuehne.cn/run/l/length_11_A.d
http://dstress.kuehne.cn/run/l/length_11_B.d


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Apr 05 2007
prev sibling next sibling parent d-bugmail puremagic.com writes:
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svv1999 hotmail.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|major                       |critical
           Priority|P2                          |P1
            Version|1.004                       |1.001





Just stumbled on this when recompiling an older project.
To me dynamic and associative arrays are key features of D.
The bug was introduced with version 1.001.
Therefore increased priority as well as severity and set Version to 1.001.

The bug shows up on upsizing only. Downsizing by assigning to length is
possible.

The type `int[int][]' is sufficient to show the bug.


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May 24 2007
prev sibling next sibling parent d-bugmail puremagic.com writes:
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Ouch.  This one just bit me too.
So throw in my "vote" or whatever.
This needs a-fixin' pronto.

Thanks for the workaround suggestion, Nick.


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May 28 2007
prev sibling next sibling parent d-bugmail puremagic.com writes:
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deewiant gmail.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|critical                    |regression




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Jul 07 2007
prev sibling next sibling parent d-bugmail puremagic.com writes:
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deewiant gmail.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |d0ccrazy web.de





*** Bug 1321 has been marked as a duplicate of this bug. ***


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Jul 07 2007
prev sibling next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=929






Here's a patch against GDC's phobos/internal/gc/gc.d that fixes the issue.
It was caused by incorrect/missing handling of the "init.length is 0" case in
array resize (the correct behavior is filling with zeroes).

diff ~/gcc/dgcc/d/phobos/internal/gc/gc.d
~/gcc/gcc-4.1.2/libphobos/internal/gc/gc.d
632c632
<     assert(initsize);
---

     // assert(initsize); // size 0 means fill with zeroes


634c634
<     assert((sizeelem / initsize) * initsize == sizeelem);
---

     assert(!initsize || ((sizeelem / initsize) * initsize == sizeelem));


714a715,719

             if (initsize == 0)
             {
                     memset(newdata + size, 0, newsize - size);
             }
             else



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Sep 08 2007
prev sibling next sibling parent d-bugmail puremagic.com writes:
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Update: The underlying issue seems to be that the wrong version of
_d_arraysetlength gets called - for zero initializers it should be ...lengthT
but ...lengthiT is what ends up being called in this case. Seems to be a
compiler bug of sorts.


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Sep 08 2007
prev sibling next sibling parent d-bugmail puremagic.com writes:
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swadenator gmail.com changed:

           What    |Removed                     |Added
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                 CC|                            |swadenator gmail.com





Is there any update to this problem?  I've been attempting to write some code
like this and have been getting exactly this error with DMD 1.026 on a win32
box.

thanks,

wade


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Feb 02 2008
prev sibling next sibling parent d-bugmail puremagic.com writes:
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gide nwawudu.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |vsb vsb.name





*** Bug 2135 has been marked as a duplicate of this bug. ***


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Jun 05 2008
prev sibling next sibling parent d-bugmail puremagic.com writes:
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-------
If I am not mistaken, Tomas fixed this in LLVMDC by providing an isZeroInit()
overload in TypeAArray that returns TRUE.


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Jul 28 2008
prev sibling next sibling parent d-bugmail puremagic.com writes:
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 Ouch.  This one just bit me too.
 So throw in my "vote" or whatever.
 This needs a-fixin' pronto.
 
 Thanks for the workaround suggestion, Nick.
 


This just bit me again!

Also one new tidbit of info: in addition to using a class to work around this
you can also wrap the AA in a struct.

struct CharToUint
{
    uint[char[]] map;
}

CharToUint[] x;  x.length = 20;  // no probs


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Oct 02 2008
prev sibling next sibling parent d-bugmail puremagic.com writes:
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-------
Just to make the patch more explicit: Adding

int TypeAArray::isZeroInit()
{
    return 1;
}

to mtype.c and the matching prototype to mtype.h fixes it. Tested in LDC.


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Oct 21 2008
prev sibling next sibling parent d-bugmail puremagic.com writes:
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If Walter's looking for low-hanging fruit, it doesn't get much lower than this.
 A 5-line diff?  Why has this been open for almost 2 years, anyway?


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Nov 14 2008
prev sibling next sibling parent d-bugmail puremagic.com writes:
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smjg iname.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |someanon yahoo.com





*** Bug 1898 has been marked as a duplicate of this bug. ***


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Nov 20 2008
prev sibling next sibling parent d-bugmail puremagic.com writes:
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smjg iname.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |smjg iname.com





From issue 1898: allocating an array of AAs using new also hangs, as in

int[int][] maps;
maps = new int[int][3];

There's a workaround, calling .dup on a static array of AAs, but it requires
that the length be known at compile time.


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Nov 20 2008
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kamm-removethis incasoftware.de changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED





-------
has been fixed in DMD 1.037 and 2.021


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Dec 02 2008
prev sibling parent d-bugmail puremagic.com writes:
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arthur.loiret gmail.com changed:

           What    |Removed                     |Added
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                 CC|                            |arthur.loiret gmail.com





Fixed in gdc SVN revision 244 as well, thanks!


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Dec 13 2008