problem w/ mingw32/egcs/msvcrt and file reads (fwd)

[Mumit Khan]

Paul Thiessen <paul@grserv.med.jhmi.edu> writes:
> Thanks for your help!
>   This isn't a big deal, but I'm just trying to understand more fully how 
> all this works: I do notice that crtdll.dll is still being linked
> in. (I tagged on an objdump -p at the end of this.) I thought from what I
> read earlier that msvcrt.dll was basically a drop-in replacement for
> crtdll.dll, but apparently that's not totally true? That there are still a
> few functions in crtdll that msvcrt doesn't have?

You're absolutely correct the crtdll is still being linked in certain
conditions, but so far I haven't seen any problems due to it. It only
happens when you use c++ or g77 (but not gcc), and the reason is the
following: the math library is defined to libcrtdll.a when we build
mingw32 compiler at compile time, and even if we use the msvcrt specs,
it gets linked in. The workaround is the following (of course, you
need to do this when if you find problems):
  
instead of:
  
  $ c++ -o foo foo.o

do,

  $ gcc -o foo foo.o -lstdc++

For g77, use gcc with -lg2c. 

The reason for not seeing any problem due to this is that msvcrt is a
superset and already resolves all the references and it never gets to
load anything from CRTDLL that conflicts. You check always check by
telling the linker to be verbose (gcc -Wl,--verbose I believe is the
right flag), which shows all the references. You can also use the
map file option, -Wl,-M, to enumerate the resolution process.

This is fixed in egcs-1.2.

Regards,
Mumit


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