Re: Unify DLSUFFIX on Darwin

On 22.06.22 15:45, Tom Lane wrote:
> Peter Eisentraut <peter.eisentraut@enterprisedb.com> writes:
>> macOS has traditionally used extension .dylib for shared libraries (used
>> at build time) and .so for dynamically loaded modules (used by
>> dlopen()).  This complicates the build system a bit.  Also, Meson uses
>> .dylib for both, so it would be worth unifying this in order to be able
>> to get equal build output.
> 
>> There doesn't appear to be any reason to use any particular extension
>> for dlopened modules, since dlopen() will accept anything and PostgreSQL
>> is well-factored to be able to deal with any extension.  Other software
>> packages that I have handy appear to be about 50/50 split on which
>> extension they use for their plugins.  So it seems possible to change
>> this safely.
> 
> Doesn't this amount to a fundamental ABI break for extensions?
> Yesterday they had to ship foo.so, today they have to ship foo.dylib.

Extensions generally only load the module files using the extension-free 
base name.  And if they do specify the extension, they should use the 
provided DLSUFFIX variable and not hardcode it.  So I don't see how this 
would be a problem.