[PATCH V2] dtc: Basic integer expressions
David Gibson
david at gibson.dropbear.id.au
Wed Apr 4 10:04:42 EST 2012
On Tue, Mar 27, 2012 at 08:24:43PM -0600, Stephen Warren wrote:
> Written by David Gibson <david at gibson.dropbear.id.au>. Additions by me:
> * Ported to ToT dtc.
> * Renamed cell to integer throughout.
> * Implemented value range checks.
> * Allow L/UL/LL/ULL suffix on literals.
> * Enabled the commented test.
>
> Signed-off-by: Stephen Warren <swarren at wwwdotorg.org>
> ---
> v2:
> * s/cell/integer/ throughout.
> * Allow signed-extended values to pass the overall cell range check.
> * Allow L/UL/LL/ULL suffix on literals. This is purely for compatibility
> with C, and has no effect on dtc's processing.
> * Enabled the 3 disabled tests.
>
> I'm not sure if the literal suffix handling is hacky or not...
>
> dtc-lexer.l | 11 +++-
> dtc-parser.y | 131 ++++++++++++++++++++++++++++++++++++++++---
> tests/Makefile.tests | 3 +-
> tests/integer-expressions.c | 117 ++++++++++++++++++++++++++++++++++++++
> tests/run_tests.sh | 5 ++
> 5 files changed, 256 insertions(+), 11 deletions(-)
> create mode 100644 tests/integer-expressions.c
>
> diff --git a/dtc-lexer.l b/dtc-lexer.l
> index 73d190c..0dbbbd5 100644
> --- a/dtc-lexer.l
> +++ b/dtc-lexer.l
> @@ -110,7 +110,7 @@ static int pop_input_file(void);
> return DT_LABEL;
> }
>
> -<V1>[0-9]+|0[xX][0-9a-fA-F]+ {
> +<V1>([0-9]+|0[xX][0-9a-fA-F]+)(L|UL|LL|ULL)? {
Should include 'U' here as well.
> yylval.literal = xstrdup(yytext);
> DPRINT("Literal: '%s'\n", yylval.literal);
> return DT_LITERAL;
> @@ -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..19db90e 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 integer;
> }
>
> %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 <integer> integer_prim
> +%type <integer> integer_unary
> +%type <integer> integer_mul
> +%type <integer> integer_add
> +%type <integer> integer_shift
> +%type <integer> integer_rela
> +%type <integer> integer_eq
> +%type <integer> integer_bitand
> +%type <integer> integer_bitxor
> +%type <integer> integer_bitor
> +%type <integer> integer_and
> +%type <integer> integer_or
> +%type <integer> integer_trinary
> +%type <integer> integer_expr
> +
> %%
>
> sourcefile:
> @@ -267,17 +284,17 @@ arrayprefix:
> $$.data = empty_data;
> $$.bits = 32;
> }
> - | arrayprefix DT_LITERAL
> - {
> - uint64_t val = eval_literal($2, 0, $1.bits);
> -
> - $$.data = data_append_integer($1.data, val, $1.bits);
> - }
> - | arrayprefix DT_CHAR_LITERAL
> + | arrayprefix integer_prim
Here is good, but you can also allow expressions in /memreserve/ lines.
> {
> - uint64_t val = eval_char_literal($2);
> + if ($1.bits < 64) {
> + uint64_t mask = (1ULL << $1.bits) - 1;
> + if (($2 > mask) && (($2 | mask) != -1ULL))
Hrm. That condition isn't the most instantly understandable.
> + print_error(
> + "integer value out of range "
> + "%016lx (%d bits)", $1.bits);
> + }
>
> - $$.data = data_append_integer($1.data, val, $1.bits);
> + $$.data = data_append_integer($1.data, $2, $1.bits);
> }
> | arrayprefix DT_REF
> {
> @@ -299,6 +316,95 @@ arrayprefix:
> }
> ;
>
> +integer_prim:
> + DT_LITERAL
> + {
> + $$ = eval_literal($1, 0, 64);
> + }
> + | DT_CHAR_LITERAL
> + {
> + $$ = eval_char_literal($1);
> + }
> + | '(' integer_expr ')'
> + {
> + $$ = $2;
> + }
> + ;
> +
> +integer_expr:
> + integer_trinary
> + ;
> +
> +integer_trinary:
> + integer_or
> + | integer_or '?' integer_expr ':' integer_trinary { $$ = $1 ? $3 : $5 }
Missing a ; at the end of the statement, likewise in a whole bunch of
the following pieces. I guess it works for you, by accident of where
;s happen to appear in the bison template, but for me at least, bison
spews a whole bunch of warnings about this.
> + ;
> +
> +integer_or:
> + integer_and
> + | integer_or DT_OR integer_and { $$ = $1 || $3 };
> + ;
> +
> +integer_and:
> + integer_bitor
> + | integer_and DT_AND integer_bitor { $$ = $1 && $3 };
> + ;
> +
> +integer_bitor:
> + integer_bitxor
> + | integer_bitor '|' integer_bitxor { $$ = $1 | $3 };
> + ;
> +
> +integer_bitxor:
> + integer_bitand
> + | integer_bitxor '^' integer_bitand { $$ = $1 ^ $3 };
> + ;
> +
> +integer_bitand:
> + integer_eq
> + | integer_bitand '&' integer_eq { $$ = $1 & $3 };
> + ;
> +
> +integer_eq:
> + integer_rela
> + | integer_eq DT_EQ integer_rela { $$ = $1 == $3; }
> + | integer_eq DT_NE integer_rela { $$ = $1 != $3; }
> + ;
> +
> +integer_rela:
> + integer_shift
> + | integer_rela '<' integer_shift { $$ = $1 < $3; }
> + | integer_rela '>' integer_shift { $$ = $1 > $3; }
> + | integer_rela DT_LE integer_shift { $$ = $1 <= $3; }
> + | integer_rela DT_GE integer_shift { $$ = $1 >= $3; }
> + ;
> +
> +integer_shift:
> + integer_shift DT_LSHIFT integer_add { $$ = $1 << $3; }
> + | integer_shift DT_RSHIFT integer_add { $$ = $1 >> $3; }
> + | integer_add
> + ;
> +
> +integer_add:
> + integer_add '+' integer_mul { $$ = $1 + $3; }
> + | integer_add '-' integer_mul { $$ = $1 - $3; }
> + | integer_mul
> + ;
> +
> +integer_mul:
> + integer_mul '*' integer_unary { $$ = $1 * $3; }
> + | integer_mul '/' integer_unary { $$ = $1 / $3; }
> + | integer_mul '%' integer_unary { $$ = $1 % $3; }
> + | integer_unary
> + ;
> +
> +integer_unary:
> + integer_prim
> + | '-' integer_unary { $$ = -$2; }
> + | '~' integer_unary { $$ = ~$2; }
> + | '!' integer_unary { $$ = !$2; }
> + ;
> +
> bytestring:
> /* empty */
> {
> @@ -364,6 +470,13 @@ static unsigned long long eval_literal(const char *s, int base, int bits)
> unsigned long long val;
> char *e;
>
> + e = strchr(s, 'U');
> + if (e)
> + *e = '\0';
> + e = strchr(s, 'L');
> + if (e)
> + *e = '\0';
> +
Hrm. This makes some assumptions about the format of the given string
that are true given the grammar, but I'd prefer not to make here.
Better, I think to handle the suffixes with a strspn() in the if (*e)
clause below.
> errno = 0;
> val = strtoull(s, &e, base);
> if (*e)
> diff --git a/tests/Makefile.tests b/tests/Makefile.tests
> index 2eee708..1795466 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 \
> + integer-expressions
> LIB_TESTS = $(LIB_TESTS_L:%=$(TESTS_PREFIX)%)
>
> LIBTREE_TESTS_L = truncated_property
> diff --git a/tests/integer-expressions.c b/tests/integer-expressions.c
> new file mode 100644
> index 0000000..d778f02
> --- /dev/null
> +++ b/tests/integer-expressions.c
> @@ -0,0 +1,117 @@
> +/*
> + * libfdt - Flat Device Tree manipulation
Not really part of libfdt
> + * 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(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),
> + 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 * 1321517ULL),
> + 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..ab8133c 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 integer-expressions -g integer-expressions.test.dts
> + run_dtc_test -I dts -O dtb -o integer-expressions.test.dtb integer-expressions.test.dts
> + run_test integer-expressions integer-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
--
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