On Wed, Jun 12, 2019 at 10:17 PM <david.tay...@dell.com> wrote: > > When doing a build, we use a pipe between GCC and GAS. > And because we wish to do some analysis of the assembly code, > we do not use -pipe but instead do '-S -c -'. And this has worked > fine for many years.
Can you please show us complete command-lines here? -S -c - will only assemble (and require source from standard input and produce output in -.s). > I was recently looking into collecting some coverage information. > To that end, I added --coverage to the invocation line. And it slowed > things down by more than an order of magnitude! > > Investigating, it appears that the problem is the writing of the GCNO > files. > > We do our builds on a build cluster with a lot of parallelism. > With the result that a dozen machines are each doing a bunch > of writes to the file '-.gcno' in an NFS mounted directory. > > Rather than have a full, not incremental, build take 5-10 minutes, > It takes 4 hours. And rather than have each of several thousand > compiles produce their own GCNO file, they all get overwritten... > > Grep'ing around, I found '-auxbase'. If I correctly understand it, > when compiling > > some/path/name.c > > into > > bin/some-product/some/path/name.o, > > I could simply say > > -auxbase $(@:%.o=%) > > The problem is that in common.opt, auxbase is marked RejectDriver. > > It looks like removing it would some my problem. Anyone have a reason > why removing that would be a bad idea? Or have a different solution? > > Thanks. > > David
