From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Ronald F. Guilmette" To: nobody@gcc.gnu.org Cc: gcc-prs@gcc.gnu.org Subject: Re: c/2678: gcc/g++ should stick compilation options into the .o file Date: Sun, 29 Apr 2001 11:56:00 -0000 Message-id: <20010429185600.30400.qmail@sourceware.cygnus.com> X-SW-Source: 2001-04/msg00730.html List-Id: The following reply was made to PR c/2678; it has been noted by GNATS. From: "Ronald F. Guilmette" To: Phil Edwards Cc: gcc-gnats@gcc.gnu.org Subject: Re: c/2678: gcc/g++ should stick compilation options into the .o file Date: Sun, 29 Apr 2001 11:47:39 -0700 In message <20010429055624.A28542@disaster.jaj.com>, you wrote: >On Sat, Apr 28, 2001 at 08:36:49PM -0000, rfg@monkeys.com wrote: >> And I don't think that it would >> be very hard to get the front-end gcc/g++ driver to pass >> ALL compilation options down to cc1 and/or cc1plus. > >We already do... How convenient! >> They >> in turn could easily still the options into a suitable ELF >> section. > >I can't see any obvious documentation of .note sections in the gas source, >and I don't see .command mentioned at all. I wouldn't mind playing with this >idea while waiting on compiles, if you can point me towards some usage docs. My alopogies if my slippery fingers typed in `.command' when I intended to write `.comment'. For documentation of the intended usage and format of data in ELF .note and .comment sections, you will need to refer to the original AT&T docu- mentation of ELF. I know that documentation (in various non-modified and slightly modified forms) is available on the web in various places, because I found it on the web in several places when I went looking for it a couple of months ago. I'll find a URL or two for you if you need them. Just let me know. Stuff that is placed into ELF .note sections is supposed to obey a very well defined format. However stuff in .comment sections is more in the nature of just free-form text lines, I believe. I can't remember anymore. What gets put into a .note section is basically 100% implementation defined, but when I glanced again at the original AT&T documentation on ELF the other day, it appears to me that the contents of .note is supposed to be, in effect, a set of name/value pairs (vaguely reminicent of UNIX environment variables). The required ``structure'' of the .note section just tells you where and how to encode one of these name/value pairs, in general.