Re: [PATCH] static buffer overflow checking

[Michael Karcher]

Am Mittwoch, den 10.09.2008, 22:12 +0200 schrieb Marcus Meissner:
> This approach will not work with -O0, which might be a problem.

If I were to decide, that would kill the patch. I really like to
recompile the dlls I am currently debugging with -O0, as that makes
following the code flow much easier. Having MultiByteToWideChar calls
fail in that case seems to make recompilation of most DLLs (that export
A and W functions) with -O0 impossible.

Regards,
  Michael Karcher

[PATCH] static buffer overflow checking

[Marcus Meissner]

On Wed, Sep 10, 2008 at 10:27:06PM +0200, Michael Karcher wrote:
> Am Mittwoch, den 10.09.2008, 22:12 +0200 schrieb Marcus Meissner:
> > This approach will not work with -O0, which might be a problem.
>
> If I were to decide, that would kill the patch. I really like to
> recompile the dlls I am currently debugging with -O0, as that makes
> following the code flow much easier. Having MultiByteToWideChar calls
> fail in that case seems to make recompilation of most DLLs (that export
> A and W functions) with -O0 impossible.

Hmm, I might stand corrected for newer gccs.

I just tested some code with -O0 and the functioncall still gets
optimized away. This is with gcc 4.1 and gcc 4.3. gcc 2.95 does not.

But frankly, I can debug similar easily with -O2. Its not that confusing.

Ciao, Marcus

[PATCH] static buffer overflow checking

[Michael Karcher]

Am Mittwoch, den 10.09.2008, 22:38 +0200 schrieb Marcus Meissner:
> I just tested some code with -O0 and the functioncall still gets
> optimized away. This is with gcc 4.1 and gcc 4.3. gcc 2.95 does not.

If it's just a performance pessimisation with -O0, I don't care. If I
get compiler or linker errors, it would be bad. I don't care about gcc
2.95 at all, so if it breaks this ancient version, so be it.
> But frankly, I can debug similar easily with -O2. Its not that confusing.

How do you set a breakpoint into a function that has been inlined? Bonus
points: That has been inlined at three different places.

Regards,
  Michael Karcher

[PATCH] static buffer overflow checking

[Marcus Meissner]

On Wed, Sep 10, 2008 at 10:50:42PM +0200, Michael Karcher wrote:
> Am Mittwoch, den 10.09.2008, 22:38 +0200 schrieb Marcus Meissner:
> > I just tested some code with -O0 and the functioncall still gets
> > optimized away. This is with gcc 4.1 and gcc 4.3. gcc 2.95 does not.
>
> If it's just a performance pessimisation with -O0, I don't care. If I
> get compiler or linker errors, it would be bad. I don't care about gcc
> 2.95 at all, so if it breaks this ancient version, so be it.
> > But frankly, I can debug similar easily with -O2. Its not that confusing.
>
> How do you set a breakpoint into a function that has been inlined? Bonus
> points: That has been inlined at three different places.

Difficult. ;)

Ciao, Marcus