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digitalmars.D.bugs - [Issue 3064] New: Invalid array operation accepted, generates bad code

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=3064

           Summary: Invalid array operation accepted, generates bad code
           Product: D
           Version: 1.045
          Platform: x86_64
               URL: http://www.digitalmars.com/d/1.0/arrays.html
        OS/Version: Linux
            Status: NEW
          Keywords: accepts-invalid, wrong-code
          Severity: major
          Priority: P2
         Component: DMD
        AssignedTo: nobody puremagic.com
        ReportedBy: matti.niemenmaa+dbugzilla iki.fi


The following compiles in DMD 1.045, but shouldn't:

void main() {
    int[] a = [1,2];
    int[] b = [1,2];
    a[] += b;
    assert (b[0] == 1);
    assert (b[1] == 2);
    assert (a[0] == 2);
    assert (a[1] == 4);
}

Currently, the code compiles but the third assertion fails, since DMD generates
code as though b were an int. Note that the following both compiles and doesn't
assert:

void main() {
    int[] a = [1,2];
    int[] b = [1,2];
    a[] += b;
    assert (b[0] == 1);
    assert (b[1] == 2);
    assert (a[0] == 1+*cast(int*)&b);
    assert (a[1] == 2+*cast(int*)&b);
}

This is, of course, nonsense.

The error is in the line 'a[] += b': according to
http://www.digitalmars.com/d/1.0/arrays.html "[t]he rvalue can be an expression
consisting either of an array slice of the same length and type as the lvalue
or an expression of the element type of the lvalue, in any combination." Thus
the line is incorrect and should read 'a[] += b[]', and that indeed works.

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Jun 11 2009
next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=3064


Don <clugdbug yahoo.com.au> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |clugdbug yahoo.com.au
         Resolution|                            |FIXED



Fixed DMD1.059 and 2.044

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May 03 2010
prev sibling next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=3064


bearophile_hugs eml.cc changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
                 CC|                            |bearophile_hugs eml.cc
         Resolution|FIXED                       |



Reopened, because this wrong code compiles still with dmd v2.044, the bug
persists:

void main() {
    int[] a = [1,2];
    int[] b = [1,2];
    a[] += b;
    assert (b[0] == 1);
    assert (b[1] == 2);
    assert (a[0] == 2);
    assert (a[1] == 4);
}

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prev sibling next sibling parent d-bugmail puremagic.com writes:
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 Reopened, because this wrong code compiles still with dmd v2.044, the bug
 persists:
 
 void main() {
     int[] a = [1,2];
     int[] b = [1,2];
     a[] += b;
     assert (b[0] == 1);
     assert (b[1] == 2);
     assert (a[0] == 2);
     assert (a[1] == 4);
 }


Oops, it's fixed only in my personal copy, not in the official DMD.

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May 03 2010
prev sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=3064


Walter Bright <bugzilla digitalmars.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|REOPENED                    |RESOLVED
                 CC|                            |bugzilla digitalmars.com
         Resolution|                            |FIXED



19:03:32 PDT ---
http://www.dsource.org/projects/dmd/changeset/509

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May 31 2010