Re: How can I get the line number and file name from GCC tree.

[Jim Wilson <wilson at specifixinc dot com>]

Matthieu Moy wrote:
> I have a GCC tree that I can print from GDB with debug_tree(t). What I
> would like is  to be able to get  back-to-source information, ie which
> file and at which line number is the source code which has been parsed
> to produce this tree. 

Historically, gcc made no attempt to track source/line info for 
expression trees.  We only keep track of this for declarations for use 
in debug info.  The front ends generated expressions trees one at a 
time, and then reduced them to RTL, so we had no need for source/line 
info for them.

Relatively recently, some front ends were modified to produce trees for 
an entire function before generating RTL, at which point source/line 
info had to be added in after the fact.  Different front ends do this 
different ways.

The STMT_LINENO macro is only used by the C family (C, Obj-C, C++).  It 
should work in those front ends.  Filenames are stored in separate 
FILE_STMT trees, and are emitted only if the filename changes.  It is 
probably better to do without this info if you can, since it may be hard 
to extract in a useful form.

Things in this area are probably a lot nicer on the tree-ssa branch, 
which has tried to design a better interface and unify the different 
language front ends to use a common interface.
--
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com