NetBSD/gnu
kristerw 980f45b693 Place EH labels on the permanent obstack. Fixes PR 18314.
Background:
Originally, the EH labels were placed on the permanent obstack, which
could end up using a lot of memory (for heavy inlining) since inlined
labels also needed to be permanent as a result of this.

This was changed in

   Wed Dec  9 09:12:40 1998  Andrew MacLeod  <amacleod@cygnus.com>

	* except.h (struct handler_info): Add handler_number field.
	* except.c (gen_exception_label): EH labels no longer need to be
	on the permanent obstack.
	(get_new_handler): Set the label number field.
	(output_exception_table_entry): Regenerate handler label reference
	from the label number field.
	(init_eh): Remove a blank line.
	* integrate.c (get_label_from_map): Labels no longer need to be
	on the permanent obstack.

by using the label numbers instead of the label structures in most cases.
The operative word here is "most" cases. Addresses to the EH RTX was still
used in (at least) flow.c, that now used freed memory. Oops.

For this to happen, the freed address of the RTX representing a EH label
must be reused for a new label that is located in dead code. delete_block()
will then see that this RTX is mentioned in the EH table, and (incorrectly)
remove the exception handler.

This might be seen when, for example, compiling
src/gnu/dist/groff/src/roff/troff/node.cc for m68k.
2002-12-16 19:33:50 +00:00
..
dist Place EH labels on the permanent obstack. Fixes PR 18314. 2002-12-16 19:33:50 +00:00
lib
libexec Avoid strict-alias warnings. 2002-12-06 09:57:58 +00:00
usr.bin we have mkstemp 2002-11-28 22:03:11 +00:00
usr.sbin
Makefile
README

README

$NetBSD: README,v 1.4 2002/09/22 09:47:56 wiz Exp $

Organization of Sources:

This directory hierarchy is using a new organization that
separates the GNU sources from the BSD-style infrastructure
used to build the GNU sources.  The GNU sources are kept in
the standard GNU source tree layout under:

	dist/*

The build infrastructure uses the normal BSD way under:

	lib/*
	usr.bin/*

The makefiles in the above hierarchy will "reach over" into
the GNU sources (src/gnu/dist) for everything they need.


Maintenance Strategy:

The sources under src/gnu/dist are generally a combination of
some published distribution plus changes that we submit to the
maintainers and that are not yet published by them.  There are
a few files that are never expected to be submitted to the FSF,
(i.e. BSD-style makefiles and such) and those generally should
stay in src/gnu/lib or src/gnu/usr.bin (the BSD build areas).

Make sure all changes made to the GNU sources are submitted to
the appropriate maintainer, but only after coordinating with the
NetBSD maintainers by sending your proposed submission to the
<tech-toolchain@netbsd.org> mailing list.  Only send the changes
to the third-party maintainers after consensus has been reached.