[SeaBIOS] iasl-option not working

[Michael S. Tsirkin]

On Thu, Aug 30, 2012 at 12:38:34PM +0300, Michael S. Tsirkin wrote:
> On Wed, Aug 29, 2012 at 09:38:00PM -0400, Kevin O'Connor wrote:
> > Hi Michael,
> > 
> > I was running through the SeaBIOS release checks when I found that the
> > new iasl-option code in the Makefile seems to choke on older versions
> > of iasl (for example, version 20120123 as shipped with fc13).  Can you
> > verify if the iasl detection still works properly for you with the
> > patch below?
> > 
> > -Kevin
> 
> So I think using -h is a bad idea: it failed once
> it might fail again.
> How about the following patch instead?
> Tested with latest iasl from git (which needs -Pn)
> and with F17 version (which does not).
> 
Scratch that, creating a temporary file without a
makefile rule will break parallel build.
Here's a version that has a proper rule.

-->

Makefile: fix iasl option detection

IASL option detection relied on iasl -h exit status which
is not very robust: -h is not expected to be used
from scripts. In particular combination of -h with
any option seems to succeed with some old
versions of iasl (e.g. version 20120123 as shipped with fc13).

Instead, supply a dummy input file and run iasl on it
to test option support.

Signed-off-by: Michael S. Tsirkin <mst at redhat.com>

---

diff --git a/Makefile b/Makefile
index 72ee152..33b3e69 100644
--- a/Makefile
+++ b/Makefile
@@ -221,14 +221,17 @@ $(OUT)vgabios.bin: $(OUT)vgabios.bin.raw tools/buildrom.py
 
 ################ DSDT build rules
 
-iasl-option=$(shell if "$(1)" "$(2)" -h > /dev/null 2>&1 \
-    ; then echo "$(2)"; else echo "$(3)"; fi ;)
+iasl-option=$(shell if "$(2)" "$(3)" "$(1)" > /dev/null 2>&1 \
+    ; then echo "$(3)"; else echo "$(4)"; fi ;)
+
+$(OUT)/iasl-test.dsl: src/iasl-test.dsl
+	$(Q)cp -f $< $@
 
-$(OUT)%.hex: src/%.dsl ./tools/acpi_extract_preprocess.py ./tools/acpi_extract.py
+$(OUT)%.hex: src/%.dsl ./tools/acpi_extract_preprocess.py ./tools/acpi_extract.py $(OUT)/iasl-test.dsl
 	@echo "  Compiling IASL $@"
 	$(Q)cpp -P $< > $(OUT)$*.dsl.i.orig
 	$(Q)$(PYTHON) ./tools/acpi_extract_preprocess.py $(OUT)$*.dsl.i.orig > $(OUT)$*.dsl.i
-	$(Q)$(IASL) $(call iasl-option,$(IASL),-Pn,) -vs -l -tc -p $(OUT)$* $(OUT)$*.dsl.i
+	$(Q)$(IASL) $(call iasl-option,$(OUT)/iasl-test.dsl,$(IASL),-Pn,) -vs -l -tc -p $(OUT)$* $(OUT)$*.dsl.i
 	$(Q)$(PYTHON) ./tools/acpi_extract.py $(OUT)$*.lst > $(OUT)$*.off
 	$(Q)cat $(OUT)$*.off > $@
 
diff --git a/src/iasl-test.dsl b/src/iasl-test.dsl
index e69de29..1a8b95e 100644
--- a/src/iasl-test.dsl
+++ b/src/iasl-test.dsl
@@ -0,0 +1,6 @@
+DefinitionBlock ("iasl-test.aml", "TEST", 0x01, "TSTC", "TESTIASLCMP", 0x1)
+{
+
+        Device (TEST) {
+        }
+}