[armedbear-devel] [rfc] Preventing stack inconsistencies - structurally

[Ville Voutilainen]

On 30 December 2010 23:39, Erik Huelsmann <ehuels at gmail.com> wrote:
> My idea would be to add a macro called WITH-STACK-PARAMETER-COLLECTION

Some snipping done. :)

> The pass1 form rewriting could be eliminated and our decision rules

Here too. :)

> Any comments?

This seems to correlate with the overall (vague) direction to which I
have envisioned
our compiler to evolve. The stack inconsistencies etc. are things that
I at least have
seen as bugs caused by our code being too manual/low-level. The
with-stack-parameter-collection
macro sounds very much like a proper tool to help with such problems, and seems
to be on the same track as some similar cleanups we've done inside pass2.

So, regarding the snips above, I wholeheartedly support the macro
idea. Regarding pass1/pass2,
please remember that the split of the two was never clear-cut to begin
with, the division of responsibilities
was muddied at best and the file-split I did at some point ages ago
was more a hatchet/chainsaw job
than any artistic sculpture job. :) The use of unsafe-p in conjunction
with half-depending on pass2 in pass1
is probably a clear sign of an incomplete design to begin with.
Therefore this sounds very much like
a step in the right direction.

If we ever aspire to have several pass2 back-ends, doing stack
analysis in pass1 is probably a bad idea
anyway.