VC7.1 bug: managed call to wcschr

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nospam@cristalink.com - 06 Oct 2004 08:26 GMT

/// Compile with "cl /Zc:wchar_t /clr bug.cpp"

#include <stdio.h>
#include <string.h>

#define TEST const wchar_t* p = wcschr( L"aa:aa", L':' ); printf(
"%ls\n", p );

#pragma managed
void f_managed()
{
TEST
}

#pragma unmanaged
void f_unmanaged()
{
TEST
}

#pragma managed
void main()
{
f_managed();
f_unmanaged();
}

Results:

(null)

:aa

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"Gary Chang" - 07 Oct 2004 07:49 GMT

Hi,

It seems not a bug of managed call to wcschr function, my opinion is that
the wcschr will return a wchar_t pointer, for C++ run-time function, the
wchar_t is defined as unsigned short which the wcschr would accept, but in
managed C++, if you compile with the /Zc:wchar_t compliance switch, the
compiler enable wchar_t as an intrinsic type System::Char, so the wcschr
call's return value is not incompatible with the System::Char* p...

I tested the program will work as expected as compile with "cl /clr
bug.cpp"

:aa
:aa

Thanks!

Best regards,

Gary Chang
Microsoft Online Partner Support

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nospam@cristalink.com - 07 Oct 2004 09:40 GMT

Thank you for your response, but you are not right.

wcschr() takes "const wchar_t*" and returns "wchar_t*". So as long as I
assign the result to "wchar_t*" or "const wchar_t*", all should work. Yes,
the bug appears only when I enable the native wchar_t type, which is not
System::Char (managed), by the way, but just a native C++ type.

The problem happens in 7.1 and fixed in 8.0, so I don't think Microsoft will
fix the bug in 7.1.

Cheers

> Hi,
>
[quoted text clipped - 20 lines]
> This posting is provided "AS IS" with no warranties, and confers no rights.
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"Gary Chang" - 08 Oct 2004 04:21 GMT

Hi,

I have consulted this problem with the VC dev team members, when you enable
the /Zc:wchar_t compliance switch, the wchar_t would be defined as managed
"chars(System::Char) in managed compile unit.

They confirmed this problem is caused by the wchar_t type is not always
marshaled correctly across managed/unmanaged transition boundaries in VC
7.1 2003.

It is a known issue in VS.NET 2003, and was fixed in Whidbey.

Thanks for your understanding!

Best regards,

Gary Chang
Microsoft Online Partner Support

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"Gary Chang" - 11 Oct 2004 02:24 GMT

Hi,

Do you have any more concerns on this issue, if so please feel free to post
here.

Good Luck!

Best regards,

Gary Chang
Microsoft Online Partner Support

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This posting is provided "AS IS" with no warranties, and confers no rights.

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VC7.1 bug: managed call to wcschr

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