Re: Patch - Debug builds without optimization

Alvaro Herrera <alvherre(at)commandprompt(dot)com> writes:
> I disagree with this change. Debug builds are very useful to have in
> production, and you don't want to be running -O0 there. I have found
> that you can use a src/Makefile.custom like this for those times when you
> want to debug stuff in a particular set of files:

> CFLAGS := $(patsubst -O2,-O0,$(CFLAGS))

> Then you remove the .o files that you want to debug, and rerun make.

FWIW, I only use Makefile.custom for more-or-less-permanent changes to
the build behavior of a particular machine. For one-shot things like
recompiling some particular file(s) at -O0, it's easier to do this:

rm foo.o
make PROFILE=-O0
reinstall postgres executable

The makefiles automatically add PROFILE at the end of CFLAGS, so you can
inject any compile flag this way --- I think the original intent was to
use it to add -pg for gprof-enabled builds. But it's handy for this.

BTW, if you're hacking Postgres code and don't already have a
"reinstall" script, you need one. Mine is basically

pg_ctl stop
cd $PGBLDROOT/src/backend
make install-bin
pg_ctl start

regards, tom lane