Re: [PATCH v1 1/1] Makefile.lib: Always rebuild DSDT

[Andy Shevchenko <andy.shevchenko@gmail.com>]

On Mon, Oct 25, 2021 at 09:18:56AM -0600, Simon Glass wrote:
> On Mon, 25 Oct 2021 at 01:34, Andy Shevchenko <andy.shevchenko@gmail.com> wrote:
> > On Sun, Oct 24, 2021 at 11:00 PM Simon Glass <sjg@chromium.org> wrote:
> > > On Wed, 20 Oct 2021 at 06:37, Andy Shevchenko
> > > <andriy.shevchenko@linux.intel.com> wrote:
> > > >
> > > > The dsdt.asl is usually combined out of several files that are included
> > > > in the main one. Whenever we change the content of any of such files,
> > > > build system is not able to recognize them. Hence the easiest way is to
> > > > force DSDT rebuild each time we run make.
> >
> > > Ick. Since it uses #include, doesn't the dependency generation work with this?
> >
> > How?
> 
> If you do a sandbox build you will see this file:
> 
> arch/sandbox/dts/.sandbox.dtb.cmd
> 
> It contains the dependencies used to compile the device tree. Can we
> use the same mechanism? There is a .cmd file for the dsdt file but it
> does not seem to have the correct contents.

A spent more than couple of hours to fight with `make` and failed.
Maybe you can improve the below (it still rebuilds always)

From 2fa93fdc376b60c69ff1a2e9ffd16d30702c6399 Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Wed, 20 Oct 2021 15:21:49 +0300
Subject: [PATCH 1/1] Makefile.lib: Always rebuild DSDT

The dsdt.asl is usually combined out of several files that are included
in the main one. Whenever we change the content of any of such files,
build system is not able to recognize them. Hence the easiest way is to
force DSDT rebuild each time we run make.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 scripts/Makefile.lib | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index ac270844c2e1..939f99dee9f9 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -432,16 +432,21 @@ CFLAGS_REMOVE_efi_freestanding.o := $(LTO_CFLAGS)
 # renamed to dsdt.c for consumption by the build system.
 ASL_TMP = $(patsubst %.c,%.asl.tmp,$@)
 
+asl_cpp_flags  = -Wp,-MD,$(depfile) -nostdinc                   \
+		 $(UBOOTINCLUDE)                                \
+		 -I$(srctree)/include                           \
+		 -D__ASSEMBLY__                                 \
+		 -undef -D__ACPI__
+
 quiet_cmd_acpi_c_asl= ASL     $<
 cmd_acpi_c_asl=         \
-	$(CPP) -x assembler-with-cpp -D__ASSEMBLY__ -D__ACPI__ \
-		-P $(UBOOTINCLUDE) -o $(ASL_TMP) $< && \
+	$(HOSTCC) -P -E $(asl_cpp_flags) -x assembler-with-cpp -o $(ASL_TMP) $< && \
 	iasl -p $@ -tc $(ASL_TMP) $(if $(KBUILD_VERBOSE:1=), >/dev/null) && \
-	mv $(patsubst %.c,%.hex,$@) $@
+	mv $(patsubst %.c,%.hex,$@) $@ && \
+	sed -i -e "s,dsdt_aml_code,AmlCode," $@
 
-$(obj)/dsdt.c:    $(src)/dsdt.asl
-	$(call cmd,acpi_c_asl)
-	$(Q)sed -i -e "s,dsdt_aml_code,AmlCode," $@
+$(obj)/dsdt.c:    $(src)/dsdt.asl FORCE
+	$(call if_changed_dep,acpi_c_asl)
 
 # Bzip2
 # ---------------------------------------------------------------------------

-- 
With Best Regards,
Andy Shevchenko