[Issue 6175] String corruption when passing static char arrays to std.conv
http://d.puremagic.com/issues/show_bug.cgi?id=6175 Kenji Hara changed: What|Removed |Added Status|NEW |RESOLVED Resolution||FIXED -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 6175] String corruption when passing static char arrays to std.conv
http://d.puremagic.com/issues/show_bug.cgi?id=6175 --- Comment #8 from github-bugzi...@puremagic.com 2012-05-22 12:40:14 PDT --- Commit pushed to master at https://github.com/D-Programming-Language/phobos https://github.com/D-Programming-Language/phobos/commit/8d455147cfa35bd514796dfc008ee67142213777 fix Issue 6175 - String corruption when passing static char arrays to std.conv -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 6175] String corruption when passing static char arrays to std.conv
http://d.puremagic.com/issues/show_bug.cgi?id=6175 Kenji Hara changed: What|Removed |Added Keywords||pull, wrong-code --- Comment #7 from Kenji Hara 2012-05-12 09:20:56 PDT --- https://github.com/D-Programming-Language/phobos/pull/575 -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 6175] String corruption when passing static char arrays to std.conv
http://d.puremagic.com/issues/show_bug.cgi?id=6175
--- Comment #6 from Steven Schveighoffer 2012-04-19
08:01:06 PDT ---
Interesting problem!
So here is what happens. The IFTI type determined for the statCArr argument is
char[9u], which means it's actually passed as a static array *by value*.
The first toImpl template matches and it looks like this:
/**
If the source type is implicitly convertible to the target type, $(D
to) simply performs the implicit conversion.
*/
T toImpl(T, S)(S value)
if (isImplicitlyConvertible!(S, T))
{
alias isUnsigned isUnsignedInt;
// Conversion from integer to integer, and changing its sign
static if (isUnsignedInt!S && isSignedInt!T && S.sizeof == T.sizeof)
{ // unsigned to signed & same size
enforce(value <= cast(S)T.max,
new ConvOverflowException("Conversion positive overflow"));
}
else static if (isSignedInt!S && isUnsignedInt!T)
{ // signed to unsigned
enforce(0 <= value,
new ConvOverflowException("Conversion negative overflow"));
}
return value;
}
Both of those static ifs fail, so it essentially boils down to this:
char[] toImpl(char[9u] value)
{
return value;
}
this means it is returning stack data! I'm surprised this is allowed to
compile, I though the compiler would disallow such obvious escaping of stack
data.
I suppose the "correct" fix is to return value.dup in this case, but I hate the
idea that the entire array is passed on the stack, seems wasteful.
Someone with better template-fu skills than me should tackle this...
BTW, what do we think the "correct" implementation *should* be? .dup the array
or return a slice of the original? I don't know if slicing is possible given
IFTI limitations.
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[Issue 6175] String corruption when passing static char arrays to std.conv
http://d.puremagic.com/issues/show_bug.cgi?id=6175
Steven Schveighoffer changed:
What|Removed |Added
CC||schvei...@yahoo.com
--- Comment #5 from Steven Schveighoffer 2012-04-19
07:44:51 PDT ---
(In reply to comment #4)
> import std.conv, std.stdio;
>
> void main()
> {
> immutable char[9] statCArr = "BlaBlaBla";
> writeln("poupoupidouwah");
> auto res1 = to!(char[])(statCArr);
> writeln(res1);
> writeln(statCArr[]);
> }
This is converting const, so to is likely doing a dup/idup. If you change res1
to immutable(char)[], it fails in the same way.
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[Issue 6175] String corruption when passing static char arrays to std.conv
http://d.puremagic.com/issues/show_bug.cgi?id=6175
SomeDude changed:
What|Removed |Added
CC||lovelyd...@mailmetrash.com
--- Comment #4 from SomeDude 2012-04-19 07:29:05
PDT ---
Isn't it the normal behaviour ?
If statCArr is declared const or immutable, it works as intended.
import std.conv, std.stdio;
void main()
{
immutable char[9] statCArr = "BlaBlaBla";
writeln("poupoupidouwah");
auto res1 = to!(char[])(statCArr);
writeln(res1);
writeln(statCArr[]);
}
PS E:\DigitalMars\dmd2\samples> rdmd bug.d
poupoupidouwah
BlaBlaBla
BlaBlaBla
PS E:\DigitalMars\dmd2\samples>
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[Issue 6175] String corruption when passing static char arrays to std.conv
http://d.puremagic.com/issues/show_bug.cgi?id=6175
--- Comment #3 from Andrej Mitrovic 2012-04-05
19:46:30 PDT ---
(In reply to comment #2)
> This has now changed to a template error:
>
> import std.conv;
>
> void main()
> {
> char[9] statCArr = "blablabla";
> auto res1 = to!(char[])(statCArr);
> }
And now in 2.058 it has reverted back to buggy behavior again:
import std.conv;
import std.stdio;
void main()
{
char[9] statCArr = "blablabla";
auto res1 = to!(char[])(statCArr);
writeln(res1);
}
$ rdmd test.d
$ B @
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[Issue 6175] String corruption when passing static char arrays to std.conv
http://d.puremagic.com/issues/show_bug.cgi?id=6175
--- Comment #2 from Andrej Mitrovic 2012-01-04
07:17:05 PST ---
This has now changed to a template error:
import std.conv;
void main()
{
char[9] statCArr = "blablabla";
auto res1 = to!(char[])(statCArr);
}
D:\DMD\dmd2\windows\bin\..\..\src\phobos\std\conv.d(237): Error: template
std.conv.toImpl(T,S) if (isImplicitlyConvertible!(S,T)) toImpl(T,S) if
(isImplicitlyConvertible!(S,T)) matches more than one template declaration,
D:\DMD\dmd2\windows\bin\..\..\src\phobos\std\conv.d(245):toImpl(T,S) if
(isImplicitlyConvertible!(S,T)) and
D:\DMD\dmd2\windows\bin\..\..\src\phobos\std\conv.d(350):toImpl(T,S) if
(isStaticArray!(S))
A simple workaround is to pass a slice:
auto res1 = to!(char[])(statCArr[]);
But since to() seems to have specializations for static arrays I'll leave this
open.
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[Issue 6175] String corruption when passing static char arrays to std.conv
http://d.puremagic.com/issues/show_bug.cgi?id=6175 --- Comment #1 from Andrej Mitrovic 2011-06-18 10:29:12 PDT --- I've noticed this while trying to add some additional capability to std.conv.to. In particular, I've added returning static arrays, and accepting wchar* and not just char* and converting that to some string/char[] type. Maybe I could have a go at fixing this too.. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
