RE: rebase not compilable

["Dave Korn" <dave dot korn at artimi dot com>]

Brian Dessent wrote on 02 June 2008 16:29:

> Is this really a good direction to move in?  The long term plan, as I
> understood it, was to simply build everything with
> --enable-auto-image-base and avoid forever the problem of having to
> manually rebase ever.  

  --enable-auto-image-base isn't magic.  We'll still get collisions.  There
are only so many <handwave> possible image bases to choose from.  Hang on a
mo, ...

static unsigned long
compute_dll_image_base (const char *ofile)
{
  unsigned long hash = strhash (ofile);
  return 0x61300000 + ((hash << 16) & 0x0FFC0000);
}
#endif

  There are only 1024 possible image bases to choose from, and any DLL >=
256kB in size will span several of them.  Collisions are an inevitability,
no?   I think we'll probably still have a need for rebase until the whole
world goes 64bit and we've got room for a few more hash buckets[*].

>> g++ -O2     -c -o sections.o sections.cc
>> sections.cc: In member function `bool Relocations::check()':
>> sections.cc:288: error: ISO C++ forbids cast to non-reference type
>> used as lvalue
>> sections.cc: In member function `bool Relocations::fix()':
>> sections.cc:331: error: ISO C++ forbids cast to non-reference type
>> used as lvalue
>> sections.cc: In member function `bool Relocations::relocate(int)':
>> sections.cc:366: error: ISO C++ forbids cast to non-reference type
>> used as lvalue
>> make: *** [sections.o] Error 1
> 
> The cast-as-lvalue was a nonstandard gcc extension that was disabled in
> C++ mode (and deprecated for C mode) starting with gcc 3.4.x.  Likely
> this package is so old that it was last built with gcc 3.3.x which still
> allowed the construct.  So, one workaround is to temporarily install the
> [prev] version of gcc-g++ and gcc-core which are the 3.3 versions.

  Sounds like a fairly horrible bodge to me, the better way would be to fix
the code, which was of dubious legality even in K'n'R days.


    cheers,
      DaveK

[*] - Noooo they be hashin' my bukket!
-- 
Can't think of a witty .sigline today....


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