[build, doc, v3] Support Sun symbol versioning in libstdc++-v3, rev. 2

[Rainer Orth]

Paolo Carlini <paolo.carlini@oracle.com> writes:

> On 07/02/2010 02:29 PM, Rainer Orth wrote:
>>> bootstrap is running with 161706, do I need to apply the patch at:
>>> http://gcc.gnu.org/ml/gcc-patches/2010-07/msg00131.html
>>>     
> The patch is already in.

Ok, thanks.

>> Shouldn't be necessary since Darwin has no GNU-style symbol versioning,
>> AFAIK.
>>   
> But note that lately Darwin has some sort of versioning, I don't know
> the details. I think we should be careful here, and make sure we really
> enable the new machinery on *solaris and solaris only* in a very direct
> and active way.

Indeed, though AFAICS only in libstdc++.  I have been extra careful to
enable Sun symbol versioning only for Solaris in libstdc++:

@@ -2834,6 +2837,20 @@
       case ${target_os} in
         darwin*)
 	  enable_symvers=darwin ;;
+	# Sun symbol versioning exists since Solaris 2.5.
+	solaris2.[[5-9]]* | solaris2.1[[0-9]]*)
+	  # make_sunver.pl needs GNU c++filt to support extern "C++" in
+	  # version scripts, so disable symbol versioning if none can be
+	  # found.
+	  if test -z "$ac_cv_path_CXXFILT"; then
+	    AC_MSG_WARN([=== You have requested Sun symbol versioning, but])
+	    AC_MSG_WARN([=== no GNU c++filt could  be found.])
+	    AC_MSG_WARN([=== Symbol versioning will be disabled.])
+	    enable_symvers=no
+	  else
+	    enable_symvers=sun
+	  fi
+	  ;;
         *)
           enable_symvers=no ;;
       esac

On the other hand, in libssp I simply check if

$ gcc -fPIC -shared -Wl,-M,./conftest.map

works.  It seems that it appears to do so on Darwin, though either with
no or with a different effect than expected.

That's the current mess with the different symbol versioning checks in
libstdc++-v3, libgomp, libgfortran, libssp, and libjava.

I meant to fix this and posted about the problem back in February

	http://gcc.gnu.org/ml/gcc/2010-02/msg00342.html

but that message met with deafening silence ;-(  I still plan to unify
this somehow, at least for GCC, but wanted to get something in for 4.6.

	Rainer

-- 
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Rainer Orth, Center for Biotechnology, Bielefeld University