569597 - Detect when ranlib is unnecessary and skip it

Status: RESOLVED FIXED

(Firefox Build System :: General, defect)

Description

[Zack Weinberg (:zwol)]

On most modern Unix systems, applying 'ranlib' to static libraries is completely unnecessary, and it can be quite slow for the very large libraries we build.  We should detect this in configure.in and set $(RANLIB) to 'true' or ':'.  'nm -s' will reveal whether a library has an index, but I don't know how portable that is.

We might also want to consider the use of 'thin' archives on systems that use GNU binutils - this is what the manual says about them:

       GNU ar can optionally create a thin archive, which contains a symbol
       index and references to the original copies of the member files of the
       archives.  Such an archive is useful for building libraries for use
       within a local build, where the relocatable objects are expected to
       remain available, and copying the contents of each object would only
       waste time and space.  Thin archives are also flattened, so that adding
       one or more archives to a thin archive will add the elements of the
       nested archive individually.  The paths to the elements of the archive
       are stored relative to the archive itself.

Comment 1

[Benjamin Smedberg]

See also related bug 522770

Comment 2

[Dan Gohman [:sunfish]]

Attachment: no-ranlib.patch

Attached is a patch which removes ranlib completely and adds the "s" flag to ar invocations. Are there any platforms which are intended to be supported which don't support this?

The patch passes a try run with -p all:

https://tbpl.mozilla.org/?tree=Try&rev=8bcc562fa45f

Comment 3

[Mike Hommey [:glandium]]

Comment on attachment 830302 [details] [diff] [review]
no-ranlib.patch

Review of attachment 830302 [details] [diff] [review]:
-----------------------------------------------------------------

We'll see if someone ever reports a problem.

Comment 4

[Dan Gohman [:sunfish]]

I noticed that there are potentially other uses of RANLIB in various auxiliary makefile things, so I just checked in the part of the patch which removes it from the rules.mk files and adds "s" to the flags:

https://hg.mozilla.org/integration/mozilla-inbound/rev/059604ce6eb7

Also, I filed bug 937685 to track the suggestion above to use "thin" archives.

Comment 5

[(PTO June 19-July 7) Ryan VanderMeulen]

https://hg.mozilla.org/mozilla-central/rev/059604ce6eb7

Comment 6

[Mike Hommey [:glandium]]

(In reply to Dan Gohman [:sunfish] from comment #4)
> I noticed that there are potentially other uses of RANLIB in various
> auxiliary makefile things

None of them are actually getting it from the main configure.