GCov data files

[Sébastien Pierre]

Hi all,

I am trying to use gcov datafiles (.bb and .bbg) files to represent the 
structure of a program, particularily to produce a graph with functions 
(nodes) and caller/callee relations (arcs).

I wrote a parser for .bb and .bbg and have difficulties in interpreting 
properly the content of these files :

- for the same source file, the number of basic blocks in .bb and in 
.bbg files differ (281 in .bb vs 593 in .bbg)
- I don't know the meaning of arc flags (spanning tree, fake edge, fall 
through)
- I don't know if I should count functions as basic blocks

Also, I came across some other questions. For instance, there is no 
unique basic block naming scheme, so how is gcov able to tell that basic 
block b from file x.c has an arc to basic block b' from file y.c ?

TIA,

 -- Sébastien