On Mon, Jul 1, 2024 at 5:32 PM Brian Norris <briannorris@xxxxxxxxxxxx> wrote: > > The dependencies in tools/lib/bpf/Makefile are incorrect. Before we > recurse to build $(BPF_IN_STATIC), we need to build its 'fixdep' > executable. > > I can't use the usual shortcut from Makefile.include: > > <target>: <sources> fixdep > > because its 'fixdep' target relies on $(OUTPUT), and $(OUTPUT) differs > in the parent 'make' versus the child 'make' -- so I imitate it via > open-coding. > > I tweak a few $(MAKE) invocations while I'm at it, because > 1. I'm adding a new recursive make; and > 2. these recursive 'make's print spurious lines about files that are "up > to date" (which isn't normally a feature in Kbuild subtargets) or > "jobserver not available" (see [1]) > > After this change, top-level builds result in an empty grep result from: > > $ grep 'cannot find fixdep' $(find tools/ -name '*.cmd') > > [1] https://www.gnu.org/software/make/manual/html_node/MAKE-Variable.html > If we're not using $(MAKE) directly, then we need to use more '+'. > > Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx> > --- > > tools/build/Makefile.include | 10 +++++++++- > tools/lib/bpf/Makefile | 6 +++++- > 2 files changed, 14 insertions(+), 2 deletions(-) > > diff --git a/tools/build/Makefile.include b/tools/build/Makefile.include > index 8dadaa0fbb43..c95e4773b826 100644 > --- a/tools/build/Makefile.include > +++ b/tools/build/Makefile.include > @@ -1,8 +1,16 @@ > # SPDX-License-Identifier: GPL-2.0-only > build := -f $(srctree)/tools/build/Makefile.build dir=. obj > > +# More than just $(Q), we sometimes want to suppress all command output from a > +# recursive make -- even the 'up to date' printout. > +ifeq ($(V),1) > + SILENT_MAKE = +$(Q)$(MAKE) > +else > + SILENT_MAKE = +$(Q)$(MAKE) --silent > +endif > + > fixdep: > - $(Q)$(MAKE) -C $(srctree)/tools/build CFLAGS= LDFLAGS= $(OUTPUT)fixdep > + $(SILENT_MAKE) -C $(srctree)/tools/build CFLAGS= LDFLAGS= $(OUTPUT)fixdep > > fixdep-clean: > $(Q)$(MAKE) -C $(srctree)/tools/build clean > diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile > index 2cf892774346..0743cf653615 100644 > --- a/tools/lib/bpf/Makefile > +++ b/tools/lib/bpf/Makefile > @@ -153,7 +153,11 @@ $(BPF_IN_SHARED): force $(BPF_GENERATED) > echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/if_xdp.h' differs from latest version at 'include/uapi/linux/if_xdp.h'" >&2 )) || true > $(Q)$(MAKE) $(build)=libbpf OUTPUT=$(SHARED_OBJDIR) CFLAGS="$(CFLAGS) $(SHLIB_FLAGS)" > > -$(BPF_IN_STATIC): force $(BPF_GENERATED) > +$(STATIC_OBJDIR): > + $(Q)mkdir -p $@ > + > +$(BPF_IN_STATIC): force $(BPF_GENERATED) | $(STATIC_OBJDIR) wouldn't $(BPF_IN_SHARED) target need a similar treatment? > + $(SILENT_MAKE) -C $(srctree)/tools/build CFLAGS= LDFLAGS= OUTPUT=$(STATIC_OBJDIR) $(STATIC_OBJDIR)fixdep > $(Q)$(MAKE) $(build)=libbpf OUTPUT=$(STATIC_OBJDIR) > > $(BPF_HELPER_DEFS): $(srctree)/tools/include/uapi/linux/bpf.h > -- > 2.45.2.803.g4e1b14247a-goog > >
