On Mon, Aug 20, 2012 at 8:35 AM, Steven Bosscher <stevenb....@gmail.com> wrote: > On Mon, Aug 20, 2012 at 11:48 AM, Jan Hubicka <hubi...@ucw.cz> wrote: >>> The summary merging in coverage.c confuses me a bit as it seems to be >>> handling the case when there are multiple program summaries in a >>> single gcda file. When would this happen? It looks like the merge >>> handling in libgcov should always produce a single program summary per >>> gcda file. > > AFAIU it merges existing profile data with new profile data from a > second (or third, or ...) trial run.
It looks like libgcov will always merge program summaries between different runs though. As far as I can tell, it will always either rewrite the whole gcda file with a single merged program summary, or abort the write if the merge was not successful. However, the comment above gcov_exit does talk about keeping program summaries separate for object files contained in different programs, which is what Honza was describing as the motivation for the coverage.c merging. But I don't see where multiple program summaries ever get written to the same gcda file - if the checksums are different it seems to abort the write. But the code in coverage.c is dealing with a single gcda file containing multiple program summaries. Is there code somewhere that will cause this to happen? Thanks, Teresa > > Ciao! > Steven -- Teresa Johnson | Software Engineer | tejohn...@google.com | 408-460-2413
