RFC: New pexecute interface

[Ian Lance Taylor]

Zack Weinberg <zack@codesourcery.com> writes:

> The interface looks sound to me with one exception: it's not safe to
> conflate !-pipe with -save-temps, because that opens up the
> possibility of a tempfile race -- if an attacker sees that the
> compiler is producing /tmp/ccQWERTY.s, then they should not be able to
> predict that the assembler will produce /tmp/ccQWERTY.o.

It is not necessarily obvious, but on a system which supports pipes
you will only get temporary files if you explicitly request them via
PEX_SAVE_TEMPS.  If you don't use PEX_SAVE_TEMPS, then the code will
always use pipes for communication.  If you do use PEX_SAVE_TEMPS,
then the caller provides the base name and the suffix, and the caller
is responsible for making good choices.

The weasel words about using temporary files when PEX_SAVE_TEMPS is
not set is for systems which do not support pipes.

> Also, why the parentheses around the numbers?

Habit.

Ian