[fpc-devel] Misterious error

José Mejuto joshyfun at gmail.com
Sat Dec 31 13:42:55 CET 2011

Hello Jonas,

Wednesday, December 28, 2011, 2:43:16 PM, you wrote:

>> To me it looks like the code is trying to free some strings or
>> interfaces but at a point where the manager of automated types has
>> been "disabled" so the declaration of a new ansistring "reconnects"
>> it. Maybe it is a crazy idea but is the only one that I have now.
JM> The most likely problem is memory corruption by your program.
JM> Compiling the program with range checking (-Cr) and dynamic class
JM> type checking (-CR) can help with finding the cause. You can try
JM> using heaptrc or Dr Memory (http://dynamorio.org/drmemory.html --
JM> in case you use this one, adding the cmem unit to your program may
JM> give more accurate diagnostics).

I had done all the tests and in fact many more, and start to manually
bisect fpc to find the revision that breaks my code as 2.4.2, 2.4.4
and 2.6.0rc1 work fine.

After 2 days and around 40 fpc and LCL clean compiles :) I had found
that the revision 19668 breaks the code. I was unable to synthesize a
test case that shows the problem, so only my code is raising the
problem constantly after that revision.

When exception is raised ebp is equal to zero and as r19668 is related
to exceptions handling it makes me think again in wrongly handled
automated types in some situations, in my case I suspect in

To compile 19667 and 19668 I had to manually apply revisions 19699 and
19670 which only affects fpdoc compilation.

How can I help more to catch the problem ?

Best regards,

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