DJGPP v2.05 and Windows 10

[Andris Pavenis (andris.pavenis@iki.fi) [via djgpp@delorie.com]]

Did some additional tests on WIndows 10.

I'm getting random compile failures with gcc-4.9.3, gcc4.5.2 and gcc 6.0.0 20151018 experimental
(last development version I built for DJGPP).
Running

echo '#include <iostream>" | gcc -E -dD -x c++ -

in loop and comparing outputs is sufficient for detecting random corruption. I have not succeeded
to find why it happens and how to workaround that.
Additionally I'm also getting random failures when trying to repeatedly compile same preprocessed
C++ file.

The situation is however not completely hopeless:
Installed gcc-3.4.6 and bootstrapped the same gcc version (3.4.6) without problems under Windows
10. No random gcc failures observed.

So some difference (or differences) between gcc-3.4.6 and recent version cause problems.
Some suspects:
- change to C++ as implementation language
- noticeable increase of size of executables and resources required by them

Andris

[Louis Santillan (lpsantil@gmail.com) [via djgpp@delorie.com]]

Andris, is it possible that you have a bad memory chip? Maybe
something in 4.x, 5.x, 6.x gcc grows the memory image into the bad
pages while 3.x does not and/or does utilize (read/write) those bad
pages.

On Sat, Oct 24, 2015 at 11:28 AM, Andris Pavenis
(andris....@iki.fi) [via dj...@delorie.com] <dj...@delorie.com>
wrote:

[Andris Pavenis (andris.pavenis@iki.fi) [via djgpp@delorie.com]]

On 10/24/2015 09:46 PM, Louis Santillan (lpsa...@gmail.com) [via dj...@delorie.com] wrote:
> Andris, is it possible that you have a bad memory chip? Maybe
> something in 4.x, 5.x, 6.x gcc grows the memory image into the bad
> pages while 3.x does not and/or does utilize (read/write) those bad
> pages.

I do not think that bed memory could be a reason. I would have noticed it log time ago
in Linux (all mentioned tests were done in Win 10 VM under Fedora 22 x86_64). I have seen
random compilation errors in Linux on a different system which was caused by RAM problems
some years ago. Never seen anything like that on this system.

Also
- initial impression is that gcc-4.4.7 is OK and works under Win10 (bootstrapped it under Win10
using gcc-3.4.6 without problems)
- some changes in environment (update VirtualBox 4.3 to VirtualBox-5.0, change of DJGPP installation
to have more than 1 gcc version installed at the same time with additional bin directories with
different
names) causes symptoms to change. Now I have one reproducible NTVDM crash I can workaround by
increasing
gcc garbage collection threshold (could be caused by memory corruption, so avoiding GC could avoid
crash)

Andris

[Andris Pavenis (andris.pavenis@iki.fi) [via djgpp@delorie.com]]

On 10/24/2015 09:46 PM, Louis Santillan (lpsa...@gmail.com) [via dj...@delorie.com] wrote:

> Andris, is it possible that you have a bad memory chip? Maybe
> something in 4.x, 5.x, 6.x gcc grows the memory image into the bad
> pages while 3.x does not and/or does utilize (read/write) those bad
> pages.

Bootstrapped gcc-4.4.7 without problems using gcc-3.4.6 as I already wrote earlier. And
after repeated once more with same version using now gcc-4.4.47. NO problems again

Wanted to choose gcc-4.7.4 as next for test but Ada compiler did not compile with gcc-4.4.7, so
continued with gcc-4.6.4. stages 1 and 2 when through without problems, but I begun to see
similar random failures in stage3. Abandoned attempt for now due to repeated random errors
(build advances a bit, but fails again in different place)

Andris