[Scons-dev] [PATCH] scons soname on OpenBSD

[Stefan Sperling]

Hi,

as discussed on IRC today, and on the OpenBSD ports list at
http://marc.info/?l=openbsd-ports&m=137831857808220&w=2,
soname support in scons 2.3.0 is interfering a little bit with
OpenBSD's way of handling shared libraries.

The patch below (against the rel_2.3.0 branch) does the minimum
necessary to prevent that. Is it acceptable?

I was thinking that instead of making behaviour conditional on the host
platform, a generic switch could be used to toggle generation of a soname,
and the same for creation of symlinks. Though perhaps that would be
overkill or conflict with scons goals, I don't know.
Anyway, the below works for me.

One additional issue is that OpenBSD uses an x.y shared library version
numbering scheme, which scons does not support. This can be worked around
by renaming shared libraries after the build.
I'm not sure how much needs to be done to fix this. There is a comment in
the VersionShLibLinkNames() function that some adjustments would need to
be made. Are there plans to support such versioning schemes in a future
release of scons?

Thanks.

Suggested log message:

[[[
OpenBSD-specific fixes for shared library handling.

Don't put a SONAME into shared lbraries, and don't create symlinks
between .so files. OpenBSD uses a different approach to shared library
handling, and in particular setting a SONAME that doesn't match the .so
file name can confuse automated checks performed by its ports framework.
See http://marc.info/?l=openbsd-ports&m=137831857808220&w=2
]]]

diff -r 05db74dca43c src/engine/SCons/Tool/__init__.py
--- a/src/engine/SCons/Tool/__init__.py	Sun Mar 03 19:34:10 2013 -0500
+++ b/src/engine/SCons/Tool/__init__.py	Thu Sep 05 16:26:07 2013 +0200
@@ -257,6 +257,10 @@
             print "VersionShLibLinkNames: linkname = ",linkname
         linknames.append(linkname)
     elif platform == 'posix':
+        if sys.platform.startswith('openbsd'):
+            # OpenBSD uses x.y shared library versioning numbering convention
+            # and doesn't use symlinks to backwards-compatible libraries
+            return []
         # For libfoo.so.x.y.z, linknames libfoo.so libfoo.so.x.y libfoo.so.x
         suffix_re = re.escape(shlib_suffix + '.' + version)
         # First linkname has no version number
@@ -302,13 +306,17 @@
     if version:
         # set the shared library link flags
         if platform == 'posix':
-            suffix_re = re.escape(shlib_suffix + '.' + version)
-            (major, age, revision) = version.split(".")
-            # soname will have only the major version number in it
-            soname = re.sub(suffix_re, shlib_suffix, libname) + '.' + major
-            shlink_flags += [ '-Wl,-Bsymbolic', '-Wl,-soname=%s' % soname ]
-            if Verbose:
-                print " soname ",soname,", shlink_flags ",shlink_flags
+            shlink_flags += [ '-Wl,-Bsymbolic' ]
+            if sys.platform.startswith('openbsd'):
+                pass # OpenBSD doesn't usually use SONAME for libraries
+            else:
+                suffix_re = re.escape(shlib_suffix + '.' + version)
+                (major, age, revision) = version.split(".")
+                # soname will have only the major version number in it
+                soname = re.sub(suffix_re, shlib_suffix, libname) + '.' + major
+                shlink_flags += [ '-Wl,-soname=%s' % soname ]
+                if Verbose:
+                    print " soname ",soname,", shlink_flags ",shlink_flags
         elif platform == 'cygwin':
             shlink_flags += [ '-Wl,-Bsymbolic',
                               '-Wl,--out-implib,${TARGET.base}.a' ]