Passing flags to linker for libstdc++ on Darwin

[Jörg Richter]

Hi,

I'm trying to build current gcc on darwin, and want the resulting GCC- 
libraries to be compatible with 10.4

This is the configure line:

gcc-4.5-20100204/configure 'CFLAGS=-isysroot /Developer/SDKs/ 
MacOSX10.4u.sdk -mmacosx-version-min=10.4' 'CXXFLAGS=-isysroot / 
Developer/SDKs/MacOSX10.4u.sdk -mmacosx-version-min=10.4' 'LDFLAGS=- 
isysroot /Developer/SDKs/MacOSX10.4u.sdk -Wl,-syslibroot,/Developer/ 
SDKs/MacOSX10.4u.sdk -mmacosx-version-min=10.4' --enable- 
languages=c,objc,c++,obj-c++

But when I look at the make output I can see that the link call for  
libstdc++ isn't using the flags. But it works for other libs like  
libgcc_s.dylib or libgomp.1.dylib

What is the correct way to pass linker-flags to libstdc++?

Thanks,
    Jörg