RE: Exception handling tables for function generated on the fly

["Dave Korn" <dave dot korn at artimi dot com>]

David Daney wrote on 12 August 2008 18:19:

> Questions like this should probably go to gcc-help@gcc.gnu.org

  Questions about deep compiler internals and EH abis?  Seems a bit intense
for the where's-the-any-key list to me...

>> I'm porting some code that does a kind of JIT 

> You don't say how you get them into memory.  Are you building a shared
> library and then loading it with dlopen()? 

  "JIT" normally implies poking opcodes straight into memory at runtime.
Otherwise it wouldn't be Just-In-Time compilation, it would be
Way-Ages-In-Advance compilation!

> If you pass -funwind-tables to gcc it will generate the necessary
> unwinding information.  If you put the code in a shared library and
> dlopen() it it should just work.  

  No compiler.  No library.  No dlopen.
 
> If you are loading the code some other way

  http://en.wikipedia.org/wiki/Just-in-time_compilation

> then you may have to call
> some of the __register_frame* family of functions (in libgcc) passing
> pointers to the appropriate .eh_frame sections of the generated code.  

  Yes.  The OP's question is "How do I generate .eh_frame data at runtime
for an arbitrary function that has no throws and no catches but may call
functions that throw".

  Tom, did you read the Dwarf spec?  That should have more info than just
the abi docs.


    cheers,
      DaveK
-- 
Can't think of a witty .sigline today....