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

[IainS <developer at sandoe-acoustics dot co dot uk>]

On 2 Jul 2010, at 14:20, IainS wrote:

> On 2 Jul 2010, at 13:58, Rainer Orth wrote:
>
> > > but no other references to "symbol" that have any bearing..
> > > so perhaps the test is not being run at all for Darwin?
> >
> > Sure it is, otherwise you wouldn't see Sun-style symbol versioning  
> > being
> > enabled.  The next test with
> >
> > gcc -fPIC -shared -Wl,-M,./conftest.map
> >
> > is the interesting one.  What happens there?  And please provide the
> > relevant output fragment of the libssp configure run, too.
>
> configure:4156: /GCC/gcc-4-6-trunk-build/./gcc/xgcc -B/GCC/gcc-4-6- 
> trunk-build/./gcc/ -B/GCC/gcc-4-6-install/i686-apple-darwin9/bin/ -B/ 
> GCC/gcc-4-6-install/i686-apple-darwin9/lib/ -isystem /GCC/gcc-4-6- 
> install/i686-apple-darwin9/include -isystem /GCC/gcc-4-6-install/ 
> i686-apple-darwin9/sys-include    -o conftest -g -O2   -fPIC -shared  
> -Wl,-M,./conftest.map conftest.c  >&5
> ld warning: in ./conftest.map, file is not of required architecture
> configure:4156: $? = 0
> configure:4166: result: sun
>
> hm.  I guess that -M is unrecognized and the linker falls back to  
> it's default which is to expect the remaining items to be objects -  
> which, of course, the ma file is not.  However, since the link does  
> not actually fail - I guess it only reports a warning.

from ld (tools version 2.5) manual page linked earlier:
-M (32-bit only) Produce a load map, listing all the segments and  
sections. The list includes the address where each input file's  
section appears in the output file, as well as the section's size.  
This option overlaps with a compiler option. If you use the compiler  
driver cc(1) to invoke ld, invoke this option in this way: -Wl,-M.
so, although it's not listed in the 3.2.x tools, I imagine that it is  
silently ignored for backward-compatibility.

Iain.