[PATCH] dinput: Mark internal symbols as hidden
chris.kcat at gmail.com
Fri Apr 29 12:48:58 CDT 2011
On Friday, April 29, 2011 7:18:47 AM Marcus Meissner wrote:
> If they are not declared hidden, the -fPIC compile generates PLT
> relocations for those symbols, even if they are internal to the dll (the
> compiler does not know what to export during our build).
> With the hidden attribute these get turned into just relative calls or
> simpler relocations.
Wouldn't it be better to compile with -fvisibility=hidden, then? Default to
hidden, then explicitly mark the functions that can be exported from the .so
(if Wine even needs PE exports to have "default" visibilty; I don't think it
does). Functions that are *never* called from outside the module may be better
marked as "internal":
"Internal visibility is like hidden visibility, but with additional processor
specific semantics. Unless otherwise specified by the psABI, GCC defines
internal visibility to mean that a function is never called from another
module. Compare this with hidden functions which, while they cannot be
referenced directly by other modules, can be referenced indirectly via
function pointers. By indicating that a function cannot be called from outside
the module, GCC may for instance omit the load of a PIC register since it is
known that the calling function loaded the correct value."
FWIW, you can even mark COM functions as "hidden". As noteded above, hidden
functions can still be called from the outside (through function pointers,
like vtables), they just aren't able to be directly referenced.
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