Long symbol names (Was: demangle doesn't work with...)

[H. S. Teoh]

On Fri, Dec 06, 2013 at 03:26:53PM -0800, Walter Bright wrote:
> On 5/27/2013 11:14 AM, Peter Alexander wrote:
> >The symbols typically contain a lot of repeated sub strings. Perhaps
> >there is a better mangling scheme that encodes it with some kind of
> >prefix tree?
> 
> Rather than a new scheme, a simple and effective approach is to
> compress using lzw. Lzw is nicely reversible, too, though the symbols
> will look like tty noise in the linker maps and the debugger.
> 
> One approach is to lzw them only if they exceed a certain length, and
> to leave a prefix that makes some sense to the user, like the function
> name.

Looking like noise shouldn't be a problem, as long as ddemangle is
updated to be able to interpret them. I doubt very many people can
demangle D symbols in their head anyway; most would use ddemangle.

Leaving the function name in is a good compromise, though not strictly
necessary if ddemangle can interpret the lzw noise.

On that note, core.demangle seriously needs to be able to demangle *all*
mangled symbols (like module ctors, typeinfos, vtables, etc.), not just
function symbols. Running `nm program | ddemangle` still leaves about
half the symbols mangled, which is annoying when you're trying to figure
out what those symbols are referring to.


T

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