Re: [Boost-users] [filesystem] Apparent non-compliant code in current operations.hpp, ...

Marty Fried wrote:

Back on Fri, 19 Oct 2007 11:37:11 +0200, in gmane.comp.lib.boost.user,Markus Schöpflin wrote:

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No worry, I just remembered that we have regression test runs for xlC on the trunk. See http://beta.boost.org/development/tests/trunk/developer/summary.html for details on the state of xlC. Looks like xlC has its problems with boost code.

I seems to me that something strange is going on; I'm not able to even compile the filesystem library without errors. It seems like the regression tests succeeded with the compile and link, if I'm reading it correctly. Could it be that the test is done with an older version of xlC, that may not have checked for this condidtion? We are using version 8; version 9 recently came out.

You can tell what version of a compiler is being used by looking at the config library's conf_info output. For the current regression results, it's reporting: IBM Visual Age version 900 _CHAR_UNSIGNED =1 _CPPUNWIND =1 __cplusplus =199711L __STDC__ =0 _WCHAR_T =1 __CHAR_UNSIGNED__ =1 __EXCEPTIONS =1 __powerpc__ =1 _WCHAR_T =1 __IBMCPP__ =900

I want to go back to aix and try the exact command line listed for the vacpp test output, to see what result I get. I'll report back.

Another aspect is that our tests are running on the code as it currently stands, not on the 1.34.1 code.

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Hmm, cxx has this to say:

cxx: Error: foo.cxx, line 6: Cannot create variable "f" of incomplete type "foo<int>". detected during instantiation of "void templatefunc<T>() [with T=int]" at line 11 foo<int> f; ------------^

Now I'm left wondering why the tests on Tru64 don't show this error. Just to be sure, do you get the error while compiling the filesystem lib itself or while using the compiled filesystem lib?

If you get the error during compilation of the library, are you sure that above code is a valid reproducer for the original problem? (I'm not implying that it isn't, I just want to make sure it is.)

I believe the test case is valid, but there is one difference that may matter here... the test case has one less level of indirection than the actual code. We didn't think it made a difference, and we wanted to simplify as much as possible; the test showed that the error is caught by xlC and Comeau, but not by gcc or msvc. However, it could be that one more level of indirection is needed to hide the error from Tru64, too. In other words, maybe Tru64 is better than gcc and MSVC at finding this test case error, but not as good as xlC/Comeau with one more level of indirection to mask it. Would you like me to modify the test case?

I appreciate your looking into this - I was worried you might dismiss it as a problem with an unsupported compiler - not that I think it really is that simple. Assuming it's really an error, it will probably eventually become a problem with a supported compiler.

If the code isn't standard compliant, I'd like to fix it. But it looks like version 9 of vacpp is accepting it, or possible the code has changed enough that the problem no longer exists.

Please let me know what I can do next to help out.

If you get some sample code that you think exactly reproduces the problem, and Comeau reports an error, please send it to me. Thanks, --Beman