[PATCH] Private symbols exported from shared library

[yugr]

Expat currently exports several private symbols which are not mentioned in public headers and thus should not be used by clients:

__bss_start
_edata
_fini
_init
XmlGetUtf16InternalEncoding  
XmlGetUtf16InternalEncodingNS
XmlGetUtf8InternalEncoding   
XmlGetUtf8InternalEncodingNS 
XmlInitEncoding              
XmlInitEncodingNS            
XmlInitUnknownEncoding       
XmlInitUnknownEncodingNS     
XmlParseXmlDecl                 
XmlParseXmlDeclNS               
XmlPrologStateInit              
XmlPrologStateInitExternalEntity
XmlSizeOfUnknownEncoding
XmlSizeOfUnknownEncoding

Removing these symbols would allow compiler to optimize code more aggressively, speed up dynamic linker on Linux and prevent clients from inadverently using internal APIs.

I attached a simple patch that hides private symbols. It passes make check (I can do additional testing if needed). Would something like this be interesting for the project?

0001-Hide-private-symbols.patch.txt

The issue was found using ShlibVisibilityChecker.

[hartwork]

Hi Yury, I still need to have a closer look. For a first quick reply: Yes, this issue is worth fixing.

[yugr]

Hi Sebastian, I've attached a slightly updated version (removes same symbols). Let me know if additional testing is needed (besides make check).

0001-Hide-private-symbols-v2.patch.txt

[yugr]

A friendly reminder.

[marcomaggi]

Maybe preparing a proper pull request would make things easier for everyone?

[yugr]

@marcomaggi There is GH-197...