Getting error: "FastMM has detected a FreeMem call after FastMM was uninstalled"

I don't think this piece of code is what triggers the message by FastMM.
You can confirm this simply by commenting out this code (or putting an exit at the first line) and see if the message still appears.

This message is probably triggered when you close your app, not by something you do while running normally.

Hi Merijn.. well I commented out the FASTMM4 declaration altogether and ran my project without FastMM. It crashed on processing the very first record this time... throwing up simply a "Invalid Pointer operation" error window. I did some tracing in debug and it crashed on this line:

StrCat(ResultStr,PChar(string(PStr^)));   // Tack on a digit to the result string

That line of code had already ran successfully exactly 7 times (it had tacked on 7 digits to "ResultStr" already)... and it was about to tack on another innocent looking digit, the number 9, when it crashed on that line. Strange eh? Could it have something to do with my declaration of variable "ResultStr"? Maybe I need to allocate a fixed amount of space to it or something.. instead of just "New(ResultStr)" ?

Thanks!
    Shawn

I wonder, if you rebuild this using just strings and chars (and skip all the pchars and pointers), does it work as expected?

OK I tried a little something here Merijn... I used GetMem and Finalize/FreeMem instead. I also took the "const" out of the function header declaration. See my new function code:

function PhoneNumMask(Str, hmask: string): PChar;
var
  Pstr, Pmask, ResultStr: PChar;
begin
  Pstr := PChar(Str);
  Pmask := PChar(hmask);
  Getmem(ResultStr, length(hmask) + 2);

  while Pmask^ <> #0 do
  begin
    if Pmask^ <> '#' then   // a literal character in the mask, output it directly
       StrCat(ResultStr,PChar(string(Pmask^)))
    else  // output a digit
    begin
      while (PStr^ <> #0) and not (PStr^ in ['0'..'9']) do
        Inc(PStr);
      if PStr^ = #0 then BREAK;  // Exit loop

      StrCat(ResultStr,PChar(string(PStr^)));   // Tack on a digit to the result string
      Inc(PStr);
    end;

    Inc(Pmask);
  end; // while Pmask^ <> #0 do

  StrCat(ResultStr, PChar(chr(13)+chr(10)));
  Result:=ResultStr;
  Finalize(ResultStr);
  FreeMem(ResultStr, length(hmask) + 2);
end;  // PhoneNumMask

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On debug, first time through this code it seems to allocate "ResultStr" fine (ResultStr = ''). It goes through the body of the procedure fine and stores a good result in ResultStr (ResultStr = '(308) 444-5555'). I noticed the "finalize(ResultStr)" line does not have a little blue dot in the left margin, so the debugger skips right over that line... odd eh? Then after the Freemem statement executes and immediately after that I check on the contents of ResultStr... it now holds some garbage looking characters. Then I step out back of the function into the next statement following the calling statement. The calling statement was:

OutPhoneNum:= PhoneNumMask(MatchAll[i,0], OutputPhoneFormats[DigitCount]);

... "OutPhoneNum" was declared as a PChar... and there was no "NEW" or "GetMen" statement for it.. should there have been? Anyway,  checking the contents of the returned value in "OutPhoneNum" showed just some garbage characters and not the good phone number I expected. So it appears something is getting "stomped" somewhere along the way.

I didn't try the function yet as using just plain strings and no pointers. I would imagine it would work just fine, but I wanted to use PChar for speed as I am calling this function many times within a tight loop.

Thanks
    Shawn

Sinisa, that worked fantastically... and no more FASTMM4 problems.

Thank you!
   Shawn