On 09/13/14 00:31, Teresa Johnson wrote:
This patch addresses issues when running gcov-tool after performing
COMDAT fixup during dyn-ipa. Functions that were previously all zero
counts are marked, and the counts are discarded when being read in
by gcov-tool before recalculating module groups and summary info.
I'm not sure I understand the design here. A few years ago I modified the gcov
data structures to cope with comdat, but failed to get the compiler side changed
to utilize that (without breaking firefox builds). You'll see each function
record (struct gcov_fn_info) has:
const struct gcov_info *key; /* comdat key */
the intent is that that points to the gcov_info object of the object file
containing the live version of the function. I couldn't quite get this to work
though -- it involves emitting a function's gcov_fn_info decl in the same comdat
group as the function itself.
You'll see the checking of gfi_ptr->key != gi_ptr in libgcov-driver.c.
Are you making use of this machinery, or inventing new machinery?
nathan
