scripts: Add decodetree.py

To be used to decode ARM SVE, but could be used for any fixed-width ISA.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

tests/Makefile.include

@@ -932,6 +932,13 @@ $(patsubst %, check-%, $(check-qapi-schema-y)): check-%.json: $(SRC_PATH)/%.json
 check-tests/qapi-schema/doc-good.texi: tests/qapi-schema/doc-good.test.texi
 	@diff -q $(SRC_PATH)/tests/qapi-schema/doc-good.texi $<
 
+.PHONY: check-decodetree
+check-decodetree:
+	$(call quiet-command, \
+	  cd $(SRC_PATH)/tests/decode && \
+          ./check.sh "$(PYTHON)" "$(SRC_PATH)/scripts/decodetree.py", \
+          TEST, decodetree.py)
+
 # Consolidated targets
 
 .PHONY: check-qapi-schema check-qtest check-unit check check-clean
@@ -940,7 +947,7 @@ check-qtest: $(patsubst %,check-qtest-%, $(QTEST_TARGETS))
 check-unit: $(patsubst %,check-%, $(check-unit-y))
 check-speed: $(patsubst %,check-%, $(check-speed-y))
 check-block: $(patsubst %,check-%, $(check-block-y))
-check: check-qapi-schema check-unit check-qtest
+check: check-qapi-schema check-unit check-qtest check-decodetree
 check-clean:
 	$(MAKE) -C tests/tcg clean
 	rm -rf $(check-unit-y) tests/*.o $(QEMU_IOTESTS_HELPERS-y)

tests/decode/check.sh

@@ -0,0 +1,18 @@
+#!/bin/sh
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+PYTHON=$1
+DECODETREE=$2
+E=0
+
+# All of these tests should produce errors
+for i in err_*.decode; do
+    if $PYTHON $DECODETREE $i > /dev/null 2> /dev/null; then
+        # Pass, aka failed to fail.
+        echo FAIL: $i 1>&2
+        E=1
+    fi
+done
+
+exit $E

tests/decode/err_argset1.decode

@@ -0,0 +1,5 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose duplicate member names
+&args	a a

tests/decode/err_argset2.decode

@@ -0,0 +1,5 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose invalid member names
+&args	a b c d0 0e

tests/decode/err_field1.decode

@@ -0,0 +1,5 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose invalid field syntax
+%field	asdf

tests/decode/err_field2.decode

@@ -0,0 +1,5 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose invalid field width.
+%field	0:33

tests/decode/err_field3.decode

@@ -0,0 +1,5 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose invalid field position.
+%field	31:2

tests/decode/err_field4.decode

@@ -0,0 +1,6 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose duplicate field name.
+%field	0:1
+%field	0:1

tests/decode/err_field5.decode

@@ -0,0 +1,5 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose duplicate function specifier.
+%field	0:1	!function=a !function=a

tests/decode/err_init1.decode

@@ -0,0 +1,6 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose uninitialized member in pattern.
+&args	a b
+insn	00000000 00000000 00000000 b:8	&args

tests/decode/err_init2.decode

@@ -0,0 +1,6 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose member initialized twice in pattern.
+&args	a b
+insn	00000000 00000000 a:8 b:8	&args a=1

tests/decode/err_init3.decode

@@ -0,0 +1,7 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose member initialized twice in pattern + format.
+&args	a
+@format	........ ........ a:16	&args
+insn	00000000 00000000 a:16	@format

tests/decode/err_init4.decode

@@ -0,0 +1,7 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose uninitialized member in pattern + format.
+&args	a b
+@format	........ ........ a:16			&args
+insn	00000000 00000000 ........ ........	@format

tests/decode/err_overlap1.decode

@@ -0,0 +1,6 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose field overlapping fixedbits.
+%field	0:1
+insn	00000000 00000000 00000000 00000000 	%field

tests/decode/err_overlap2.decode

@@ -0,0 +1,6 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose field overlapping fixedbits w/format.
+@format		........ ........ ........ ....... fld:1
+insn		00000000 00000000 00000000 00000000		@format

tests/decode/err_overlap3.decode

@@ -0,0 +1,6 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose field overlapping unspecified bits.
+%field	0:1
+insn	00000000 00000000 00000000 --------	%field

tests/decode/err_overlap4.decode

@@ -0,0 +1,6 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose fixed bits overlapping unspecified bits.
+@format		........ ........ ........ .......-
+insn		00000000 00000000 00000000 00000000	@format

tests/decode/err_overlap5.decode

@@ -0,0 +1,5 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose overlapping sub-fields.
+%field	3:5 0:5

tests/decode/err_overlap6.decode

@@ -0,0 +1,6 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose overlapping fixed bits w/format.
+@format		........ ........ ........ .......1
+insn		00000000 00000000 00000000 00000000	@format

tests/decode/err_overlap7.decode

@@ -0,0 +1,6 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose overlapping patterns.
+insn1		00000000 00000000 00000000 00000000
+insn2		00000000 00000000 00000000 00000000

tests/decode/err_overlap8.decode

@@ -0,0 +1,5 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose not specified bit (. vs -).
+insn	00000000 00000000 00000000 0000000.

tests/decode/err_overlap9.decode

@@ -0,0 +1,6 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose not specified bit (. vs -) w/format.
+@format		........ a:8      ........ b:7 .
+insn		00000000 ........ 00000000 ........	@format