[Bug lto/48538] GCC build fails with -flto in BOOT_CFLAGS

["jafb at tinet dot org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48538

--- Comment #4 from jafb at tinet dot org 2011-04-17 09:59:35 UTC ---
Mmmm.... I'm afraid using --with-build-config=bootstrap-lto crashes at the same
point with the same error.
As a workaround, can I compile the ada frontend after installing the rest,
without lto? How?
I have one doubt about compiling the ada frontend (sorry if I shouldn't be
asking this here). Documentation of --enable-threads config option looks to
tell that the correct option for ada targets is --enable-threads=gnat, but this
is equivalent to single for other targets. Should I compile everything except
ada with default threading library (I guess posix) and separately the ada
frontend with --enable-threads=gnat? Or am I misunderstanding?

By the way, make doesn't look to honor --with-build-config=bootstrap-O3. I'm
not an expert at all in Makefiles, but looking at the generated Makefile, the
file is included after setting STAGE_CFLAGS to the value of BUILD_CFLAGS (and
other variables from STAGE_CFLAGS). Of course, if BUILD_CFLAGS is altered after
that, these variables are not correspondingly altered.

More things I've found in my adventure of trying nonstandard options for
building:

- When using make -jn, when linking it claims to go back to -j1 because
(something about jobserver, if I remember right) and says that '+' should be
added to the top-level rule of the Makefile. Is this on purpose or '+' should
have automatically been added?

- Adding -mcmodel=large to BOOT_CFLAGS crashes (I think it's the assembler).
-mcmodel=medium works. But I don't understand very well how these options work.
Will the compiler have more available memory for data if I use medium model?
Does this afect the heap or only static memory? And more important, will the
compiler work correctly if it's compiled with these options?

Thanks a lot, and sorry again if any of my comments should not be here,

Juan