[PATCH] dtc: Basic cell expressions

Stephen Warren swarren at wwwdotorg.org
Wed Mar 21 13:29:11 EST 2012


Written by David Gibson <david at gibson.dropbear.id.au>. Ported to ToT
dtc by me. Added >> test. Commented a couple of failing tests.

Signed-off-by: Stephen Warren <swarren at wwwdotorg.org>
---
This is a port of David's cell expressions patch to ToT. It passes all
enabled tests, but a few fail and are commented out.
 dtc-lexer.l              |    9 +++
 dtc-parser.y             |  119 +++++++++++++++++++++++++++++++++++++++++---
 tests/Makefile.tests     |    3 +-
 tests/cell-expressions.c |  123 ++++++++++++++++++++++++++++++++++++++++++++++
 tests/run_tests.sh       |    5 ++
 5 files changed, 249 insertions(+), 10 deletions(-)
 create mode 100644 tests/cell-expressions.c

diff --git a/dtc-lexer.l b/dtc-lexer.l
index 73d190c..c7d31cc 100644
--- a/dtc-lexer.l
+++ b/dtc-lexer.l
@@ -164,6 +164,15 @@ 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; };
+
 <*>.		{
 			DPRINT("Char: %c (\\x%02x)\n", yytext[0],
 				(unsigned)yytext[0]);
diff --git a/dtc-parser.y b/dtc-parser.y
index 348616b..39bef4b 100644
--- a/dtc-parser.y
+++ b/dtc-parser.y
@@ -56,10 +56,12 @@ static unsigned char eval_char_literal(const char *s);
 	struct node *node;
 	struct node *nodelist;
 	struct reserve_info *re;
+	uint64_t cell;
 }
 
 %token DT_V1
 %token DT_MEMRESERVE
+%token DT_LSHIFT DT_RSHIFT DT_LE DT_GE DT_EQ DT_NE DT_AND DT_OR
 %token DT_BITS
 %token <propnodename> DT_PROPNODENAME
 %token <literal> DT_LITERAL
@@ -86,6 +88,21 @@ static unsigned char eval_char_literal(const char *s);
 %type <node> subnode
 %type <nodelist> subnodes
 
+%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:
@@ -267,17 +284,12 @@ arrayprefix:
 			$$.data = empty_data;
 			$$.bits = 32;
 		}
-	| arrayprefix DT_LITERAL
-		{
-			uint64_t val = eval_literal($2, 0, $1.bits);
-
-			$$.data = data_append_integer($1.data, val, $1.bits);
-		}
-	| arrayprefix DT_CHAR_LITERAL
+	| arrayprefix cell_prim
 		{
-			uint64_t val = eval_char_literal($2);
+			if (($1.bits < 64) && ($2 >= (1ULL << $1.bits)))
+				print_error("cell value out of range");
 
-			$$.data = data_append_integer($1.data, val, $1.bits);
+			$$.data = data_append_integer($1.data, $2, $1.bits);
 		}
 	| arrayprefix DT_REF
 		{
@@ -299,6 +311,95 @@ arrayprefix:
 		}
 	;
 
+cell_prim:
+	  DT_LITERAL
+		{
+			$$ = eval_literal($1, 0, 64);
+		}
+	| DT_CHAR_LITERAL
+		{
+			$$ = eval_char_literal($1);
+		}
+	| '(' 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:
 	  /* empty */
 		{
diff --git a/tests/Makefile.tests b/tests/Makefile.tests
index 2eee708..930d1a5 100644
--- a/tests/Makefile.tests
+++ b/tests/Makefile.tests
@@ -19,7 +19,8 @@ LIB_TESTS_L = get_mem_rsv \
 	dtbs_equal_ordered \
 	dtb_reverse dtbs_equal_unordered \
 	add_subnode_with_nops path_offset_aliases \
-	utilfdt_test
+	utilfdt_test \
+	cell-expressions
 LIB_TESTS = $(LIB_TESTS_L:%=$(TESTS_PREFIX)%)
 
 LIBTREE_TESTS_L = truncated_property
diff --git a/tests/cell-expressions.c b/tests/cell-expressions.c
new file mode 100644
index 0000000..17b601a
--- /dev/null
+++ b/tests/cell-expressions.c
@@ -0,0 +1,123 @@
+/*
+ * 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),
+	// Fails: Probably because cell values can't be negative
+	//TE(-0x21524111),
+	TE(1+1),
+	TE(2*3),
+	TE(4/2),
+	TE(10/3),
+	TE(19%4),
+	TE(1 << 13),
+	TE(0x1000 >> 4),
+	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),
+	// Fails: Probably related to MSB being set implying negative?
+	//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),
+	// Fails:
+	// tests/cell-expressions.c:69:2: error: integer overflow in expression [-Werror=overflow]
+	// Can be fixed by adding ULL to a constant below, but dtc doesn't
+	// support that, so dtc errors out.
+	//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 %ld\n",
+			     reslen, ARRAY_SIZE(expr_table) * sizeof(uint32_t));
+
+		for (i = 0; i < ARRAY_SIZE(expr_table); i++)
+			if (fdt32_to_cpu(res[i]) != expr_table[i].result)
+				FAIL("Incorrect result for expression \"%s\","
+				     " 0x%x instead of 0x%x\n",
+				     expr_table[i].expr, fdt32_to_cpu(res[i]),
+				     expr_table[i].result);
+	}
+
+	PASS();
+}
diff --git a/tests/run_tests.sh b/tests/run_tests.sh
index e470b82..16af5ee 100755
--- a/tests/run_tests.sh
+++ b/tests/run_tests.sh
@@ -404,6 +404,11 @@ 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
-- 
1.7.5.4



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