dump-translation-unit format

Sascha Alexander Jopen jopen@gmx.net
Fri Mar 9 14:14:00 GMT 2007


I'm currently working on the output of gcc/g++ -fdump-translation-unit to do
source code analysis. I found several references that the internal ast
should include nodes for for, while and do constructs. But I can't find
those nodes in the dumped files. Sometimes there are such FOR_STMT nodes
when I compile large units, but when compiling a small test unit containing
not much more than a for loop, this loop isn't included in the dump. Instead
there is a GOTO_EXPR where I would expect the for loop. This holds for other
loops and conditional expressions as well. All FOR_STMT nodes I encountered
where not from my custom code, but from templates from system includes.

Are there any optimizations done on the tree before dumping it, and how can
I prevent this to get an unoptimized tree? Are there other possibilities to
get those loop nodes? I need them to check whether function calls are done
in loops or not. Without the bodies of loops I can get information about
functions called from other functions using the chain links, but not whether
they are called within loops.

Another thing I don't understand is the following. This dumped function node
contains two body definitions, one undefined and one with a proper node
chain. Is this a dump error or has it special meaning?

@1639   function_decl    name: @2001    mngl: @2002    type: @2003   
                         scpe: @812     srcp: char_traits.h:322    
                         chan: @2004    note: member   accs: pub     
                         args: @2005    body: undefined 
                         link: extern   body: @2006

Maybe someone could help me or point me to other resources.

Thanks in advance,
Sascha Jopen

More information about the Gcc-help mailing list