On 18/05/18 13:28, Marco van de Voort wrote:
In our previous episode, Mattias Gaertner said:
ISO7185: "After a for-statement is executed, other than being left by a
goto-statement, the
control-variable shall be undefined"
http://docwiki.embarcadero.com/RADStudio/Tokyo/en/Declarations_and_Statements_(Delphi)#For_Statements:
"After the for statement terminates (provided this was not forced by a Break or
an Exit procedure),
the value of counter is undefined."
So this shall not be unrolled, but is still error prone, if Result is not set
after the regular end of the for loop.
To avoid misunderstandings:
The above clearly says, that using break/goto/exit is safe:
Well, well, clearly. One could interpret it that it says that the for
statement terminates naturally if not forced by break or exit. It doesn't
say what happens with break or exit.
The fact that this exception is not documented with an example makes it very
ambiguous IMHO.
To make it unambiguous: the value of the counter variable of a for-loop
is well-defined after interrupting the for-loop using exit or break,
also in FPC.
Jonas
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