[gnu.gcc.bug] Differences in stage{1,2,3} .o files under System V

rfg@nsc.nsc.com (Ron Guilmette) (11/25/88)

In a recent posting to bug-gcc, sun!apple.com!satyr!local writes:

>My system is: Altos 1000 running Unix System 5.3.1b. It's a
>386 box.
>
>I made the stage1 and stage2 compilers. Everything was fine.
>Running the compare on the object files, I always get:
>
>c-convert.o stage2/c-convert.o differ: char 5, line 1
>version.o stage2/version.o differ: char 5, line 1
>....
>ad nauseam...
>
>That is, every object file differs at char 5, line 1.

I have *always* experienced the same thing when building GCC on System V.
I learned long ago to just ignore it.  I have always figured that as long
as I could successfully get through building all 3 stages then things must
be mostly right.

>Examining ho.o and ho.o.orig, the *only* place they differ is character
>5, which seems to be set to a random value at each compilation (with the
>same compiler!).
>
>Any ideas??? It seems that perhaps some static memory is not getting
>correctly initialized...

I doubt that the differences are due to "random" values.  My theory is that
"date/time of compilation" information is being put into the COFF object
files so that they will always be different for different compilation
dates/times.  I have no evidence for this view.  It is just a theory
based on total ignorance.

Ron Guilmette
National SemiConductor, 1135 Kern Ave. M/S 7C-266; Sunnyvale, CA 94086
Internet: rfg@nsc.nsc.com   or   amdahl!nsc!rfg@ames.arc.nasa.gov
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