Re: Memory leaks (detected by Valgrind)

["Marc Nieper-Wißkirchen" <marc.nieper+gnu@gmail.com>]

Am Sa., 18. Dez. 2021 um 17:45 Uhr schrieb David Malcolm <dmalcolm@redhat.com>:

[...]

> IIRC I tried that approach, and the maintainer (Joseph Myers, I think),
> wasn't keen on it, but this was a few years ago.  I've tried finding
> the discussion in the archives, but couldn't.  IIRC, he preferred
> adding a flag to strings in gcc.c, tracking if they needed to be freed.
> I'm CCing Joseph.   FWIW there's a class in libcpp/include/line-map.h:
> class label_text which does this.  Perhaps it could be used for this
> (and maybe renamed???)

Using label_text (suitably renamed) everywhere looks like the most
elegant solution but it would be a very invasive change to the
existing code of gcc.c. It contains and uses a lot of functions that
handle strings and allocate new ones (like find_file or concat), which
would have to be rewritten to take a label_text argument.

A much simpler solution is IMO to maintain a vector of pointers that
have to be eventually freed. A function

template <typename T>
T *gc (T *s)

adds the argument to the vector of addresses to be garbage-collected
(= freed) later.

Many calls to, say, concat would then be rewritten in the form

gc (concat (...))

Marc