Using GCC as a C++ front-end.

[Matthieu Moy <Matthieu dot Moy at imag dot fr>]

Hi ! 

I'm using GCC as a front-end to  C++ to do some code analysis (No code
generation). 

For now, I'm using the main branch,  but I may shift to the SSA branch
later. 

For  that, I've  added a  function  call to  my code  the line  before
"optimize_function  (fn);" in  semantics.c. In  the function  added, I
keep a "copy" of fn, but this is only a copy of the pointer. 

I  thought  the  tree  wouldn't   be  modified  by  the  rest  of  the
compilation, but  actually, this  is not  the case :  The call  to the
function  "expand_stmt (DECL_SAVED_TREE  (fn));" later  in semantics.c
can change  it. It did so for  a node of type  TARGET_EXPR. The second
operand is deleted. 

So, I have two questions :

* Is there a  way to be sure  the tree will not be  modified after the
  call to my  function ? A way to stop the  treatment of this function
  at this point ? (for now, I'm still generating assembler code, which
  is totally useless !)

* If not, is there  a way to get an exact "deep" copy  of a tree ? (By
  "deep", I mean not just a copy of pointer, but a recursive copy.) 

Thanks for your help,

-- 
Matthieu