Am 23.06.2011 23:03, schrieb Martin: > And what exactly does checkpointer check?
Check if the pointer points into a allocated memory block. Combined with heaptrc.keep_released:=true, this is a very powerful check and even more if heaptrc is compiled with FPC_HEAPTRC_EXTRA. Downside is a slight slow down and a heavily increased memory consumption because keep_released:=true forces the heap manager never to reused a used memory block so checkpointer finds any dangling pointer. But I think it finds almost all pointer related problems. With the default settings (keep_released:=false) it gets not all of them because a memory block might be already reallocated and the pointer might look valid. I propose this because my standard procedure if something strange happens and I suspect heap corruption and pointer problemes: - compile with -gh - use keep_released:=true - use a heaptrc unit compiled with FPC_HEAPTRC_EXTRA > > That s is not nil ? => s will never be nil. If something goes wrong, s > points to memory of which nothing is known (could be unallocated, could > be allocated by something else) Not with heaptrc.keep_released:=true > > On 23/06/2011 21:37, Florian Klämpfl wrote: >> Am 23.06.2011 22:36, schrieb Martin: >>>> procedure Foo(const s: string); >>>> begin >>>> proc; >>> I assume the below is supposed to be the hidden / automatic check? >> Yes. >> >>> (since the above was the unwarranted change to s) >>> >>> But what does it test (besides from being an assignment? >> This is only to demonstrate that checkpointer detects the error. >> _______________________________________________ >> fpc-devel maillist - fpc-devel@lists.freepascal.org >> http://lists.freepascal.org/mailman/listinfo/fpc-devel > > _______________________________________________ > fpc-devel maillist - fpc-devel@lists.freepascal.org > http://lists.freepascal.org/mailman/listinfo/fpc-devel > _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
