Re: DWARF-2 EH for MinGW gcj?

[Mohan Embar <gnustuff at thisiscool dot com>]

Hi Danny,

Thanks so much for answering this. It sounds like
you're doing some amazing and much-needed work.

>I promise to submit a Part 1 patch by end of this week. If you would
>like to review first, I can send you working version.

What does Part 1 do? I wouldn't mind looking at this, although
it will probably be Greek to me.

Out of curiosity, how does one go about learning about these matters
so as to be fluent in them like you are (EH, GCC Internals, Win32
executable format)? I've dug up some links (like this one: 
http://gcc.gnu.org/onlinedocs/gccint/) but I'm missing the bigger
picture and can't seem to easily find how to get it. Is it just
a matter of being patient and putting years of time? (I'd really
like to be able to read a post like this:

http://gcc.gnu.org/ml/gcc/2002-11/msg00149.html

...without scratching my head and shrugging my shoulders helplessly.)

>Part 2  builds libgcc amd libstdc++ as dlls (c++ frontend patch for
>typeinfo linkage needed for latter).
>This takes care of EH across dll/exe bounds for C++with out need for
>shared-ptr hackery

I'm assuming that this would mean that application developers would
need to ship these DLLs with their applications. Would this preclude
monolithic statically-linked executables? What are the GPL implications
of this?

>c++ frontend patch for typeinfo linkage needed for latter

Does this patch already exist?

>I haven't gotten around to testing libgcj.dll mainly because my machine
>lacks grunt.  Recent patches to
>ld make sorting of section by name less time-consuming, so building the
>dll is not so painfull.  

I've got some grunt :), so if you want to send things my way and have me
test, I'd be happy to do so.

>. >- Is the only issue you know about the foreign stack
>. >frame issue? Or are there other caveats you know about?
>
>AFAIK, this is the only significant issue. 

...

>. >
>. >- Any ideas or hunches on how to solve this problem?
>An attribute  __attibute__/pragma ((frame_wormhole_clue)) added to
>foreign libcall
>declarations to put state information into callee of such functions?

Aren't these all __stdcall declarations anyway? (Like I said, I know
very little about this stuff.) 

>From what I understand of MSVC compiler for Vista, EH unwind is handled
>using DWARF2-like tables.  Does anyone have any more info?  

Not me. If you want, I have some ancient contacts at Microsoft that
I could dig up.... (I haven't signed any NDAs with them.)

-- Mohan
http://www.thisiscool.com/
http://www.animalsong.org/