Re: [libvirt] [PATCH v2] Check for --no-copy-dt-needed linker flag

On Mon, Aug 19, 2013 at 11:37:24AM -0600, Eric Blake wrote: > On 08/19/2013 11:28 AM, Guido Günther wrote: > > and use it when available > > --- > > configure.ac | 1 + > > m4/virt-linker-no-indirect.m4 | 30 ++++++++++++++++++++++++++++++ > > src/Makefile.am | 9 +++++++++ > > tests/Makefile.am | 1 + > > 4 files changed, 41 insertions(+) > > create mode 100644 m4/virt-linker-no-indirect.m4 > > > > > +AC_DEFUN([LIBVIRT_LINKER_NO_INDIRECT],[ > > + AC_MSG_CHECKING([for how to avoid indirect lib deps]) > > + > > + NO_INDIRECT_LDFLAGS= > > + `$LD --help 2>&1 | grep -- "--no-copy-dt-needed-entries" >/dev/null` && \ > > Doesn't do what you think (it tries to execute the output of grep - > which is thankfully empty on both success and failure). Also wastes a > fork on grep, compared to the simpler: I was looking following virt-linker-relro.m4 and I'm getting the correct result since the output is always empty but for the non matching case grep exits with 1. However > > case `$LD --help 2>&1` in > *--no-copy-dt-needed-entries*) NO_INDIRECT_LDFLAGS=... ;; > esac this looks nicer. > > > +++ b/src/Makefile.am > > @@ -1813,6 +1813,7 @@ libvirt_la_LDFLAGS = \ > > $(LIBVIRT_NODELETE) \ > > $(AM_LDFLAGS) \ > > $(RELRO_LDFLAGS) \ > > + $(NO_INDIRECT_LDFLAGS) \ > > Why aren't you building this directly into $(AM_LDFLAGS) once, rather > than having to copy it into each and every library recipe? > > Why only src/ and tests/? What about tools/ and daemon/? Again following the above example. I'll come up with a v3. Cheers,