dtc expression support revisited
David Gibson
david at gibson.dropbear.id.au
Thu Aug 21 15:45:16 EST 2008
On Wed, Aug 20, 2008 at 04:59:04PM +1000, David Gibson wrote:
> Now that dtc 1.2 is out, we've talked about implementing the
> long-suggested expression support. So, I've taken my old prototype
> integer expression support patch and updated it to apply to the
> current tree.
>
> This wants some more work before merging; implementing the remaining C
> integer operators, at least. But it's got enough to play with, and
> the expressions are a lot less confusing in dts-v1, without the
> implicitly hex literals.
And here's a revised version of the patch, with a more structured
testcase, and more expression types implemented. This now implements
all side-effect-free C integer operators.
Index: dtc/dtc-parser.y
===================================================================
--- dtc.orig/dtc-parser.y 2008-08-04 15:32:39.000000000 +1000
+++ dtc/dtc-parser.y 2008-08-21 15:32:36.000000000 +1000
@@ -53,6 +53,7 @@ static unsigned long long eval_literal(c
%token DT_V1
%token DT_MEMRESERVE
+%token DT_LSHIFT DT_RSHIFT DT_LE DT_GE DT_EQ DT_NE DT_AND DT_OR
%token <propnodename> DT_PROPNODENAME
%token <literal> DT_LITERAL
%token <literal> DT_LEGACYLITERAL
@@ -72,7 +73,6 @@ static unsigned long long eval_literal(c
%type <addr> addr
%type <data> celllist
%type <cbase> cellbase
-%type <cell> cellval
%type <data> bytestring
%type <prop> propdef
%type <proplist> proplist
@@ -83,6 +83,21 @@ static unsigned long long eval_literal(c
%type <nodelist> subnodes
%type <labelref> label
+%type <cell> cell_prim
+%type <cell> cell_unary
+%type <cell> cell_mul
+%type <cell> cell_add
+%type <cell> cell_shift
+%type <cell> cell_rela
+%type <cell> cell_eq
+%type <cell> cell_bitand
+%type <cell> cell_bitxor
+%type <cell> cell_bitor
+%type <cell> cell_and
+%type <cell> cell_or
+%type <cell> cell_trinary
+%type <cell> cell_expr
+
%%
sourcefile:
@@ -254,7 +269,7 @@ celllist:
{
$$ = empty_data;
}
- | celllist cellval
+ | celllist cell_prim
{
$$ = data_append_cell($1, $2);
}
@@ -277,7 +292,7 @@ cellbase:
| DT_BASE
;
-cellval:
+cell_prim:
DT_LITERAL
{
$$ = eval_literal($1, 0, 32);
@@ -286,6 +301,71 @@ cellval:
{
$$ = eval_literal($2, $1, 32);
}
+ | '(' cell_expr ')'
+ {
+ $$ = $2;
+ }
+ ;
+
+cell_expr: cell_trinary
+ ;
+
+cell_trinary: cell_or
+ | cell_or '?' cell_expr ':' cell_trinary { $$ = $1 ? $3 : $5 }
+ ;
+
+cell_or: cell_and
+ | cell_or DT_OR cell_and { $$ = $1 || $3 };
+
+cell_and: cell_bitor
+ | cell_and DT_AND cell_bitor { $$ = $1 && $3 };
+ ;
+
+cell_bitor: cell_bitxor
+ | cell_bitor '|' cell_bitxor { $$ = $1 | $3 };
+ ;
+
+cell_bitxor: cell_bitand
+ | cell_bitxor '^' cell_bitand { $$ = $1 ^ $3 };
+ ;
+
+cell_bitand: cell_eq
+ | cell_bitand '&' cell_eq { $$ = $1 & $3 };
+ ;
+
+cell_eq: cell_rela
+ | cell_eq DT_EQ cell_rela { $$ = $1 == $3; }
+ | cell_eq DT_NE cell_rela { $$ = $1 != $3; }
+ ;
+
+
+cell_rela: cell_shift
+ | cell_rela '<' cell_shift { $$ = $1 < $3; }
+ | cell_rela '>' cell_shift { $$ = $1 > $3; }
+ | cell_rela DT_LE cell_shift { $$ = $1 <= $3; }
+ | cell_rela DT_GE cell_shift { $$ = $1 >= $3; }
+ ;
+
+cell_shift: cell_shift DT_LSHIFT cell_add { $$ = $1 << $3; }
+ | cell_shift DT_RSHIFT cell_add { $$ = $1 >> $3; }
+ | cell_add
+ ;
+
+cell_add: cell_add '+' cell_mul { $$ = $1 + $3; }
+ | cell_add '-' cell_mul { $$ = $1 - $3; }
+ | cell_mul
+ ;
+
+cell_mul: cell_mul '*' cell_unary { $$ = $1 * $3; }
+ | cell_mul '/' cell_unary { $$ = $1 / $3; }
+ | cell_mul '%' cell_unary { $$ = $1 % $3; }
+ | cell_unary
+ ;
+
+cell_unary: cell_prim
+ | '-' cell_unary { $$ = -$2; }
+ | '~' cell_unary { $$ = ~$2; }
+ | '!' cell_unary { $$ = !$2; }
;
bytestring:
Index: dtc/tests/run_tests.sh
===================================================================
--- dtc.orig/tests/run_tests.sh 2008-08-20 15:59:58.000000000 +1000
+++ dtc/tests/run_tests.sh 2008-08-21 14:33:20.000000000 +1000
@@ -283,6 +283,11 @@ dtc_tests () {
run_dtc_test -I dtb -O dts -o stdin_odts_test_tree1.dtb.test.dts - < test_tree1.dtb
run_wrap_test cmp stdin_odts_test_tree1.dtb.test.dts odts_test_tree1.dtb.test.dts
+ # Check integer expresisons
+ run_test cell-expressions -g cell-expressions.test.dts
+ run_dtc_test -I dts -O dtb -o cell-expressions.test.dtb cell-expressions.test.dts
+ run_test cell-expressions cell-expressions.test.dtb
+
# Check for graceful failure in some error conditions
run_sh_test dtc-fatal.sh -I dts -O dtb nosuchfile.dts
run_sh_test dtc-fatal.sh -I dtb -O dtb nosuchfile.dtb
Index: dtc/dtc-lexer.l
===================================================================
--- dtc.orig/dtc-lexer.l 2008-08-20 13:54:53.000000000 +1000
+++ dtc/dtc-lexer.l 2008-08-21 15:20:31.000000000 +1000
@@ -202,6 +202,15 @@ static int pop_input_file(void);
<*>{COMMENT}+ /* eat C-style comments */
<*>{LINECOMMENT}+ /* eat C++-style comments */
+<*>"<<" { return DT_LSHIFT; };
+<*>">>" { return DT_RSHIFT; };
+<*>"<=" { return DT_LE; };
+<*>">=" { return DT_GE; };
+<*>"==" { return DT_EQ; };
+<*>"!=" { return DT_NE; };
+<*>"&&" { return DT_AND; };
+<*>"||" { return DT_OR; };
+
<*>. {
yylloc.file = srcpos_file;
yylloc.first_line = yylineno;
Index: dtc/tests/Makefile.tests
===================================================================
--- dtc.orig/tests/Makefile.tests 2008-08-21 13:39:35.000000000 +1000
+++ dtc/tests/Makefile.tests 2008-08-21 13:40:01.000000000 +1000
@@ -11,6 +11,7 @@ LIB_TESTS_L = get_mem_rsv \
move_and_save mangle-layout nopulate \
open_pack rw_tree1 set_name setprop del_property del_node \
string_escapes references path-references boot-cpuid incbin \
+ cell-expressions \
dtbs_equal_ordered \
add_subnode_with_nops path_offset_aliases
LIB_TESTS = $(LIB_TESTS_L:%=$(TESTS_PREFIX)%)
Index: dtc/tests/cell-expressions.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ dtc/tests/cell-expressions.c 2008-08-21 15:33:31.000000000 +1000
@@ -0,0 +1,115 @@
+/*
+ * libfdt - Flat Device Tree manipulation
+ * Testcase for dtc expression support
+ * Copyright (C) 2008 David Gibson, IBM Corporation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+#include <errno.h>
+
+
+#include <fdt.h>
+#include <libfdt.h>
+
+#include "tests.h"
+#include "testdata.h"
+
+struct test_expr {
+ const char *expr;
+ uint32_t result;
+} expr_table[] = {
+#define TE(expr) { #expr, (expr) }
+ TE(0xdeadbeef),
+ TE(-0x21524111),
+ TE(1+1),
+ TE(2*3),
+ TE(4/2),
+ TE(10/3),
+ TE(19%4),
+ TE(1 << 13),
+ TE(3*2+1), TE(3*(2+1)),
+ TE(1+2*3), TE((1+2)*3),
+ TE(1 < 2), TE(2 < 1), TE(1 < 1),
+ TE(1 <= 2), TE(2 <= 1), TE(1 <= 1),
+ TE(1 > 2), TE(2 > 1), TE(1 > 1),
+ TE(1 >= 2), TE(2 >= 1), TE(1 >= 1),
+ TE(1 == 1), TE(1 == 2),
+ TE(1 != 1), TE(1 != 2),
+ TE(0xabcdabcd & 0xffff0000),
+ TE(0xdead4110 ^ 0xf0f0f0f0),
+ TE(0xabcd0000 | 0x0000abcd),
+ TE(~0x21524110), TE(~~0xdeadbeef),
+ TE(0 && 0), TE(17 && 0), TE(0 && 17), TE(17 && 17),
+ TE(0 || 0), TE(17 || 0), TE(0 || 17), TE(17 || 17),
+ TE(!0), TE(!1), TE(!17), TE(!!0), TE(!!17),
+ TE(0 ? 17 : 39), TE(1 ? 17 : 39), TE(17 ? 0xdeadbeef : 0xabcd1234),
+ // TE(11 * 257 * 1321517),
+ TE(123456790 - 4/2 + 17%4),
+};
+
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+
+int main(int argc, char *argv[])
+{
+ void *fdt;
+ const uint32_t *res;
+ int reslen;
+ int i;
+
+ test_init(argc, argv);
+
+ if ((argc == 3) && (strcmp(argv[1], "-g") == 0)) {
+ FILE *f = fopen(argv[2], "w");
+
+ if (!f)
+ FAIL("Couldn't open \"%s\" for output: %s\n",
+ argv[2], strerror(errno));
+
+ fprintf(f, "/dts-v1/;\n");
+ fprintf(f, "/ {\n");
+ fprintf(f, "\texpressions = <\n");
+ for (i = 0; i < ARRAY_SIZE(expr_table); i++)
+ fprintf(f, "\t\t(%s)\n", expr_table[i].expr);
+ fprintf(f, "\t>;\n");
+ fprintf(f, "};\n");
+ fclose(f);
+ } else {
+ fdt = load_blob_arg(argc, argv);
+
+ res = fdt_getprop(fdt, 0, "expressions", &reslen);
+
+ if (!res)
+ FAIL("Error retreiving expression results: %s\n",
+ fdt_strerror(reslen));
+
+ if (reslen != (ARRAY_SIZE(expr_table) * sizeof(uint32_t)))
+ FAIL("Unexpected length of results %d instead of %d\n",
+ reslen, ARRAY_SIZE(expr_table) * sizeof(uint32_t));
+
+ for (i = 0; i < ARRAY_SIZE(expr_table); i++)
+ if (res[i] != expr_table[i].result)
+ FAIL("Incorrect result for expression \"%s\","
+ " 0x%x instead of 0x%x\n",
+ expr_table[i].expr, res[i],
+ expr_table[i].result);
+ }
+
+ PASS();
+}
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
More information about the devicetree-discuss
mailing list