Bug 21549

Summary:	Configure options are poorly documented
Product:	gcc	Reporter:	Paolo Carlini <paolo.carlini>
Component:	libstdc++	Assignee:	Not yet assigned to anyone <unassigned>
Status:	NEW ---
Severity:	normal	CC:	bkoz, egallager, gcc-bugs, iains, pinskia, sjames, webrown.cpp
Priority:	P2	Keywords:	documentation
Version:	4.0.0
Target Milestone:	---
See Also:	https://gcc.gnu.org/bugzilla/show_bug.cgi?id=13756 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82824
Host:		Target:
Build:		Known to work:
Known to fail:		Last reconfirmed:	2005-12-15 04:52:33

Description Paolo Carlini 2005-05-13 14:48:05 UTC

It looks like people often have trouble finding the libstdc++-specific configure
options. It is suggested, very sensibly in my opinion, that the documentation
should be added to http://gcc.gnu.org/install/configure.html, in a specific
section - similarly to Fortran/Java(libgcj) and so on - or, maybe, linked from
there. This idea makes even more sense now that libstdc++-v3 is a integral
part of the GCC project.

Comment 1 Andrew Pinski 2005-05-13 18:01:45 UTC

Confirmed, --with-pic being documented would be very nice even though it is a generic libtool 
configure option, it is most used with libstdc++ as shown by the bug reports about the using static 
libstdc++ in a shared library.

Comment 2 Paolo Carlini 2010-02-05 13:12:35 UTC

Benjamin, any opinion about this issue?

Comment 3 Benjamin Kosnik 2010-02-05 17:40:49 UTC

Would love to see something standardized for all libs in gcc. My preference is to have libstdc++ config docs linked to in gcc docs. (No duplication, just alias.)

One thing that could be done would be to add a "C++ Specific Option" to
http://gcc.gnu.org/install/configure.html

And link to 
http://gcc.gnu.org/onlinedocs/libstdc++/manual/configure.html

Or options on that page, don't care.

As an aside, are a lot of these java config opts actually still relevant?

-benjamin

Comment 4 Eric Gallager 2017-08-31 16:57:10 UTC

There's always ./configure --help=recursive from the top level; the "recursive" makes it print the help text from subdirs like libstdc++ too.

Comment 5 Eric Gallager 2017-11-30 12:23:59 UTC

The issue of undocumented configure options also came up in bug 82824, although that was a tangent so I won't add it under "See Also" 

(In reply to Benjamin Kosnik from comment #3)
> 
> As an aside, are a lot of these java config opts actually still relevant?
> 
> -benjamin

No, java has been removed.

Comment 6 Eric Gallager 2019-03-03 04:39:50 UTC

(In reply to Eric Gallager from comment #5)
> The issue of undocumented configure options also came up in bug 82824,
> although that was a tangent so I won't add it under "See Also" 
> 

Actually I've changed my mind; I now believe that even tangents are sufficient for "See Also" status.

Comment 7 Eric Gallager 2021-10-09 15:35:55 UTC

(In reply to Andrew Pinski from comment #1)
> Confirmed, --with-pic being documented would be very nice even though it is
> a generic libtool 
> configure option, it is most used with libstdc++ as shown by the bug reports
> about the using static 
> libstdc++ in a shared library.

Note that documenting it has the risk of leading people to think that --with-pic (or --without-pic) is ok to use even in situations when it's not; e.g. x86_64 must always be PIC. If the flag is going to be documented, any such restrictions should be documented as well.

Comment 8 Eric Gallager 2022-05-24 14:57:43 UTC

retitling