Re: building gcc

[Brendon Costa <brendon at christian dot net>]

Bob Rossi wrote:
> 
> Thanks Brendon, that was really helpful. I'm very new at this, and may 
> have some seemingly rather odd questions. I see that global_namespace is
> of type 'union tree_node'. Is this the C++ language dependent AST?

Yes, this is the C++ AST. I actually think it is just a superset of
GENERIC. I.e. it uses a lot of stuff defined in the tree.def file but
also has some stuff specific to C++ that is defined in the cp-tree.def file.

>From what i have gathered ALL tree types use this "union tree" type to
represent a node in the tree. A good place to start in the documentation
is the GCC internals documentation:

http://gcc.gnu.org/onlinedocs/gccint/

There is a section on:
The intermediate representations used by the C and C++ front ends

that describes a lot of useful information about the C++ front end tree.
This C++ tree includes the nodes for the C tree also, so look in the
files tree.def, cp-tree.def for documentation on the different types of
nodes that can be found in this tree.

In addition the file: tree.h contains a number of functions and macros
that can be used for manipulating and checking the contents of tree
nodes. A lot of this information is in the above documentation, but some
things you just need to search the sources for.

I find that if something doesn't have any documentation, i search the.c
files for uses of it using grep and see how it is used to get some idea
of what it does.

Finally there is a lot of documentation in the source files. I just find
it difficult searching for the correct macro/function to use to do what
i want. Once I have found it, using it is not as big of an issue.

Brendon.