cross-module inlining (was Re: using gcj for a different language- is it possible?)

[Jeff Sturm <jsturm at one-point dot com>]

On 8 Jan 2004, Tom Tromey wrote:
> Offhand I don't remember what sort of inlining we can do.  We're sort
> of moving away from doing inlining by default, since that breaks
> binary compatibility.  But, yes, if the user asks for it, gcj will
> inline methods, hopefully even across class boundaries.

I've been thinking a little about this since it can restrict inlining,
escape analysis, and any other sort of useful IPA gcj might perform.

C/C++ have a related problem that public functions cannot normally be
inlined into library code because they may be overriden by the dynamic
linker at runtime.  This inlining is controlled by the binds_local_p
target hook.  The default hook checks flag_pic to determine if it is
compiling a shared library or not.

Similarly in Java, why not leave the most aggressive optimizations for the
main executable (non-PIC) and stick to conservative binary-compatible
optimizations for libraries?  Does binary compatibility really matter for
non-library code?

If not, maybe there is no need for a special flag.

Jeff