Re: GCC tree access & Pretty-print

[Pop Sébastian <pop at gauvain dot u-strasbg dot fr>]

Hi,

On Thu, Mar 13, 2003 at 01:37:15PM -0500, Jeffrey Richardson wrote:
> I was wondering if you (or anyone else at gcc.gnu.org) could tell me how the
> pretty-print capability works?  I see alot of code starting with
> pp_c_pretty_printer_init, but I cannot decern how it is used.  Is this a debugging
> capability that has to be turned on in the code?  If so, how do you do so?
> 
These functions are used in mainline for printing diagnostic messages (such as 
errors or warnings).  In the tree-ssa branch we have a set of functions 
debug_generic_*, debug_c_* that we use for dumping the trees in a c-like syntax.  
The dumped format is not compilable.  

> As before, any examples that anyone can provide for either the pretty-print stuff,
> or accessing trees in general would be greatly appreciated.
> 

For accessing trees you could follow the instructions given in: 
-  http://gcc.gnu.org/bugs/reghunt.html  for getting and installing the sources,
-  http://gcc.gnu.org/bugs/segfault.html  gives some instructions for debugging GCC.

You can for example insert a "browse_tree (fndecl);" in 
"tree-optimize.c: optimize_function_tree (fndecl)"
rebuild the compiler and compile with -O2 foo.c.

You can insert this kind of code where you want in the compiler. You can also call 
the tree browser from gdb "call browse_tree (some_tree_node)".  There are also 
the "debug_*" functions that dump on stderr useful information about structures.

> Also, If anyone has instructions on the best way quickly test changes to the gcc
> code, I would like to see them.  I downloaded the CVS tree, did a "configure" to
> /usr/local, did a "make bootstrap", and then a "make install".  I find that to test
> changes I need to do a "make" in objdir, and then do another "make install" (as
> root), to get the changes.  The "make install" takes quite a bit of time.  Is there
> a faster way to test changes that I make to the code?
> 
You can use the cc1* compilers from objdir/gcc/ once you have built GCC: 
for example "objdir/gcc/cc1 -O2 foo.c", or 
"gdb objdir/gcc/cc1" and then "(gdb) run -O2 foo.c"

	Sebastian