Re: Is it feasible to cross-build compat5x binary?

From: Bruce Evans (bde_at_zeta.org.au)
Date: 10/24/05

  • Next message: Martin Cracauer: "Re: Is it feasible to cross-build compat5x binary?" 
    Date: Mon, 24 Oct 2005 22:09:11 +1000 (EST)
To: Martin Cracauer <cracauer@cons.org>

    On Mon, 24 Oct 2005, Martin Cracauer wrote:

    > Peter Jeremy wrote on Mon, Oct 24, 2005 at 06:08:11PM +1000:
    >> On Sun, 2005-Oct-23 16:29:35 -0700, David O'Brien wrote:
    >>> We should no trust cross built libraries for this purpose at this time.
    >>> We really don't know how identical the results will be to being natively
    >>> built.
    >>
    >> At some stage, we need to validate our cross-build chain with cmp(1).
    >
    > ELF object files are timestamped. But there's some elf-cmp out there.

    On libraries (ELF or not: .so or .a) are.

    I use diff -r to check that builds of object trees give reproducible
    results, and just ignore libraries since they are built up from object
    files by a simple process (perhaps not so simple for .so's). The main
    problem at least used to be braindamaged applications that create
    irreproducible results using the following methods:
    - version.c files with a unique version number or timestamp
    - __DATE__ in C files. Results are reproducible until the next day
    - __TIME__ in C files
    - __FILE__ in C files. For {source,generated} files, this makes the
       results depend on the location of the {source,object} tree.

    Bruce
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