Re: [Qemu-devel] [PATCH] make: explicit dependencies for ACPI gen sources

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Aug 05, 2015 at 11:50:54AM +0200, Paolo Bonzini wrote:
> 
> 
> On 04/08/2015 18:21, Victor Kaplansky wrote:
> > Rebuilding QEMU after switching versions from git can cause make failure
> > if IASL is enabled. This is caused by including stale *.d info from
> > previous build.
> > 
> > To prevent this in the future we generate dependency info for generated
> > ACPI sources in *.dep instead regular *.d and include them explicitly.
> > This will allow us not to break future builds when one of such generated
> > sources is removed - by removing explicit include of removed dependency.
> > 
> > By itself this doesn't fix broken builds from the past and this will be
> > done by the following patch.
> 
> Does this happen the same way if you are removing a .c file?  If not,
> can the same solution be used for .c and .dsl files?
> 
> Paolo

The problem is with .hex, not with .dsl files.
It will happen with .c or .h file as well if .c/.h file is generated.


> > Signed-off-by: Victor Kaplansky <victork@redhat.com>
> > ---
> >  hw/i386/Makefile.objs | 4 +++-
> >  rules.mak             | 1 +
> >  2 files changed, 4 insertions(+), 1 deletion(-)
> > 
> > diff --git a/hw/i386/Makefile.objs b/hw/i386/Makefile.objs
> > index bd4f147..bcc7083 100644
> > --- a/hw/i386/Makefile.objs
> > +++ b/hw/i386/Makefile.objs
> > @@ -10,13 +10,15 @@ obj-y += acpi-build.o
> >  hw/i386/acpi-build.o: hw/i386/acpi-build.c \
> >  	hw/i386/acpi-dsdt.hex hw/i386/q35-acpi-dsdt.hex
> >  
> > +-include hw/i386/acpi-dsdt.dep hw/i386/q35-acpi-dsdt.dep
> > +
> >  iasl-option=$(shell if test -z "`$(1) $(2) 2>&1 > /dev/null`" \
> >      ; then echo "$(2)"; else echo "$(3)"; fi ;)
> >  
> >  ifdef IASL
> >  #IASL Present. Generate hex files from .dsl
> >  hw/i386/%.hex: $(SRC_PATH)/hw/i386/%.dsl $(SRC_PATH)/scripts/acpi_extract_preprocess.py $(SRC_PATH)/scripts/acpi_extract.py
> > -	$(call quiet-command, $(CPP) -x c -P $(QEMU_DGFLAGS) $(QEMU_INCLUDES) $< -o $*.dsl.i.orig, "  CPP $(TARGET_DIR)$*.dsl.i.orig")
> > +	$(call quiet-command, $(CPP) -x c -P $(QEMU_DGFLAGS_GEN) $(QEMU_INCLUDES) $< -o $*.dsl.i.orig, "  CPP $(TARGET_DIR)$*.dsl.i.orig")
> >  	$(call quiet-command, $(PYTHON) $(SRC_PATH)/scripts/acpi_extract_preprocess.py $*.dsl.i.orig > $*.dsl.i, "  ACPI_PREPROCESS $(TARGET_DIR)$*.dsl.i")
> >  	$(call quiet-command, $(IASL) $(call iasl-option,$(IASL),-Pn,) -vs -l -tc -p $* $*.dsl.i $(if $(V), , > /dev/null) 2>&1 ,"  IASL $(TARGET_DIR)$*.dsl.i")
> >  	$(call quiet-command, $(PYTHON) $(SRC_PATH)/scripts/acpi_extract.py $*.lst > $*.off, "  ACPI_EXTRACT $(TARGET_DIR)$*.off")
> > diff --git a/rules.mak b/rules.mak
> > index aec27f8..6019a46 100644
> > --- a/rules.mak
> > +++ b/rules.mak
> > @@ -18,6 +18,7 @@ QEMU_CXXFLAGS = -D__STDC_LIMIT_MACROS $(filter-out -Wstrict-prototypes -Wmissing
> >  
> >  # Flags for dependency generation
> >  QEMU_DGFLAGS += -MMD -MP -MT $@ -MF $(*D)/$(*F).d
> > +QEMU_DGFLAGS_GEN += -MMD -MP -MT $@ -MF $(*D)/$(*F).dep
> >  
> >  # Same as -I$(SRC_PATH) -I., but for the nested source/object directories
> >  QEMU_INCLUDES += -I$(<D) -I$(@D)
> > --