Re: gcc forgets to decrease esp after function call

[Vladimir Simonov <Vladimir dot Simonov at acronis dot com>]

Andrew Haley wrote:
> Vladimir Simonov writes:
>  > 
>  > Andrew Haley wrote:
>  > > Unfortunately, this does not produce a test case.
>  > > 
>  > > To be clear: if you want this bug to be addressed, oy must produce a
>  > > test case that someone can run.  You must also provide the expected
>  >  > output.
>  > 
>  > Sorry for delay with answer. I union both your letters.
>  > 
>  > Are you able to reproduce my results using
>  > gcc 4.1.2/4.1.1?
>
> I didn't look in deatil.  Once I have a test case I will do so.
>
>  > Do you agree with my analysis?
>  > 
>  > Do you mean I must add "main", body of called
>  > function, script to build executable and show that
>  > it crashes instead of print "Hello word"?
>  
> That will do.
>
>  >  > Well, yeah, but that would break lots of other people's prgrams too,
>  >  > and we know that doesn't happen.  So I want to know what is so special
>  >  > about yours.
>  > 
>  > If you take a look at source you'll see that it is quite complex
>  > templated code.
>
> We have lots of that too.
>
>  > I think the difference is in its complexity.  Say, gcc 4.0.2 can't
>  > compile our projects at all due to "internal compiler error'.
>
> Well, that's an easy test case too.  But really, I wouldn't use gcc
> 4.0.x.
>
>  > And we made some efforts to make gcc 4.1.1 to compile the
>  > sources. Now it can compile without internal crash but produced
>  > code is incorrect :(
>
> Sure, but once I have a test case I can try a bunch of different
> compilers.  And then we can figure out why the error is occurring,
> etc...
>
> Andrew.

Hi

The attached test case can be built by compile.sh.
It produces two binaries - test_bin_bad & test_bin_good.

test_bin_good prints "Hello word" before exit.
test_bin_bad crashes.

The difference is the only -O2 used while test_bin_bad build.

The symptoms are the same - incorrect esp usage in caller
after call function returning object.

We reproduced the bug in gcc 4.1.0/4.1.1/4.1.2
gcc 3.x can't compile the sources.

Regards
Vladimir

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