in reply to Re^4: [C Question] Determine if gcc provides erfl() function
in thread [C Question] Determine if gcc provides erfl() function

... so I might investigate that path instead.
Why? From what I see, the smoker is working as intended. The functions are not available on that platform and trying to use them ends in failure.

Standard C gives the specification for many functions; this allows the compiler to make optimizations. Such as replacing a memcpy() with immediate moves. Or replacing a printf() by puts(), etc. Or eliminating a function call that has no effect...

What you need to test is the presence of a function *in the system library*. Thus, for the purpose of said test, you can (a) make a sufficiently complicated test, avoiding constants; (b) disable the compilers awareness of those functions by disabling c99 mode, or by using -fno-builtin.

Gcc defines its internal builtins with the expectation that fallback is available. But if the libm is deficient... Using gnu tools on a non-gnu platform, you may run into problems like that.

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Re^6: [C Question] Determine if gcc provides erfl() function
by syphilis (Archbishop) on Jun 04, 2015 at 09:40 UTC
    (a) make a sufficiently complicated test, avoiding constants

    Ok - I'll start with that, keeping the other options in mind.
    I'll reply to this post, giving details of the solution I used when I find that solution.

    Thanks for your input.

    Cheers,
    Rob
[reply]
      I'll reply to this post, giving details of the solution I used when I find that solution.

      Avoiding constants in the test-executable seems to have done the trick, and I can understand how that would have worked.
      At least, there have been no FAIL reports from any NetBSD machines (and only one FAIL all up.).

      However, I was expecting that the NetBSD FAIL reports should have been replaced with UNKNOWN NetBSD reports.
      The Makefile.PL should be doing an "exit 0;", and an "exit 0;" from the Makefile.PL is supposed to result in an UNKNOWN report, isn't it ? But there have been *no* reports at all from NetBSD.

      So, I don't really know that my current version of the module has even been looked at by a NetBSD machine. (In the past, the NetBSD reports have begun filtering through within 24 hours, but that doesn't really count for much.)

      Cheers,
      Rob
[reply]

        Suppose the test was to merely pass a flag like -DMISSING_foo, and that in your XS you'd provide a respective stub instead of the missing function? (The stub would raise an exception ie die.) Is the lack of powl/erfl so critical that there'd be no point in providing the package without them?

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