This patch exercises the new expression infrastructure to implement syntax
to concatenate and repeat strings. We use syntax inspired by Python,
with '+' overloaded for string concatenation and '*' overloaded for string
repeat. Normally we'd use C syntax to inspire dts syntax, but C has no
obvious candidates for these string operators.
Signed-off-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
---
dtc.h | 4 ++
expression.c | 117 ++++++++++++++++++++++++++++++++++++++++++++-
tests/.gitignore | 1 +
tests/Makefile.tests | 2 +-
tests/run_tests.sh | 5 ++
tests/string-expressions.c | 97 +++++++++++++++++++++++++++++++++++++
6 files changed, 223 insertions(+), 3 deletions(-)
create mode 100644 tests/string-expressions.c
diff --git a/dtc.h b/dtc.h
index d270626..d3f8ad0 100644
--- a/dtc.h
+++ b/dtc.h
@@ -302,6 +302,10 @@ DEF_BINARY_OP(logic_and);
DEF_BINARY_OP(logic_or);
+struct expression *expression_concat(struct srcpos *pos,
+ struct expression *arg0,
+ struct expression *arg1);
+
struct expression *expression_conditional(struct srcpos *pos,
struct expression *,
struct expression *,
diff --git a/expression.c b/expression.c
index 8d6474b..2b86fed 100644
--- a/expression.c
+++ b/expression.c
@@ -294,9 +294,7 @@ INT_UNARY_OP(logic_not, !)
INT_BINARY_OP(mod, %)
INT_BINARY_OP(div, /)
-INT_BINARY_OP(mul, *)
-INT_BINARY_OP(add, +)
INT_BINARY_OP(sub, -)
INT_BINARY_OP(lshift, <<)
@@ -317,6 +315,121 @@ INT_BINARY_OP(bit_or, |)
INT_BINARY_OP(logic_and, &&)
INT_BINARY_OP(logic_or, ||)
+/*
+ * We need to write out add and mul in full, since they can be used on
+ * both integer and string arguments with different meanings
+ */
+
+static struct expression_value op_eval_mul(struct expression *expr,
+ enum expr_type context)
+{
+ struct expression_value arg0, arg1;
+ struct expression_value v;
+ uint64_t n, i;
+ struct data s;
+ struct data d = empty_data;
+
+ assert(expr->nargs == 2);
+ EVALUATE(arg0, expr->arg[0], EXPR_VOID);
+ EVALUATE(arg1, expr->arg[1], EXPR_VOID);
+
+ if ((arg0.type == EXPR_INTEGER) && (arg1.type == EXPR_INTEGER)) {
+ v.type = EXPR_INTEGER;
+ v.value.integer = arg0.value.integer * arg1.value.integer;
+ return v;
+ } else if ((arg0.type != EXPR_INTEGER) && (arg0.type != EXPR_STRING)) {
+ return type_error(expr->arg[0], "Expected integer or string"
+ " expression (found %s)",
+ expression_typename(arg0.type));
+ } else if (arg0.type == EXPR_INTEGER) {
+ if (arg1.type != EXPR_STRING)
+ return type_error(expr->arg[1], "Expected string"
+ " expression (found %s)",
+ expression_typename(arg1.type));
+ n = arg0.value.integer;
+ s = arg1.value.d;
+ } else {
+ assert(arg0.type == EXPR_STRING);
+ if (arg1.type != EXPR_INTEGER)
+ return type_error(expr->arg[1], "Expected integer"
+ " expression (found %s)",
+ expression_typename(arg1.type));
+ n = arg1.value.integer;
+ s = arg0.value.d;
+ }
+
+ for (i = 0; i < n; i++)
+ d = data_append_data(d, s.val, s.len - 1);
+
+ v.type = EXPR_STRING;
+ v.value.d = data_append_byte(d, 0); /* Terminating \0 */
+
+ return v;
+}
+static struct operator op_mul = {
+ .name = "*",
+ .evaluate = op_eval_mul,
+};
+struct expression *expression_mul(struct srcpos *loc,
+ struct expression *arg0,
+ struct expression *arg1)
+{
+ return expression_build(loc, &op_mul, arg0, arg1);
+}
+
+static struct expression_value op_eval_add(struct expression *expr,
+ enum expr_type context)
+{
+ struct expression_value arg0, arg1;
+ struct expression_value v;
+
+ assert(expr->nargs == 2);
+ EVALUATE(arg0, expr->arg[0], EXPR_VOID);
+ EVALUATE(arg1, expr->arg[1], EXPR_VOID);
+ if ((arg0.type != EXPR_INTEGER) && (arg0.type != EXPR_STRING))
+ return type_error(expr->arg[0], "Expected integer or string"
+ " expression (found %s)",
+ expression_typename(arg0.type));
+ if ((arg1.type != EXPR_INTEGER) && (arg1.type != EXPR_STRING))
+ return type_error(expr->arg[0], "Expected integer or string"
+ " expression (found %s)",
+ expression_typename(arg1.type));
+
+ if (arg0.type != arg1.type)
+ return type_error(expr, "Operand types to + (%s, %s) don't match",
+ expression_typename(arg0.type),
+ expression_typename(arg1.type));
+
+ v.type = arg0.type;
+
+ switch (v.type) {
+ case EXPR_INTEGER:
+ v.value.integer = arg0.value.integer + arg1.value.integer;
+ break;
+
+ case EXPR_STRING:
+ v.value.d = data_copy_mem(arg0.value.d.val,
+ arg0.value.d.len - 1);
+ v.value.d = data_append_data(v.value.d, arg1.value.d.val,
+ arg1.value.d.len);
+ break;
+
+ default:
+ assert(0);
+ }
+ return v;
+}
+static struct operator op_add = {
+ .name = "+",
+ .evaluate = op_eval_add,
+};
+struct expression *expression_add(struct srcpos *loc,
+ struct expression *arg0,
+ struct expression *arg1)
+{
+ return expression_build(loc, &op_add, arg0, arg1);
+}
+
static struct expression_value op_eval_conditional(struct expression *expr,
enum expr_type context)
{
diff --git a/tests/.gitignore b/tests/.gitignore
index bb5e33a..7931067 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -48,6 +48,7 @@ tmp.*
/setprop_inplace
/sized_cells
/string_escapes
+/string-expressions
/subnode_iterate
/subnode_offset
/supernode_atdepth_offset
diff --git a/tests/Makefile.tests b/tests/Makefile.tests
index dafb618..fa4e2d2 100644
--- a/tests/Makefile.tests
+++ b/tests/Makefile.tests
@@ -20,7 +20,7 @@ LIB_TESTS_L = get_mem_rsv \
dtb_reverse dtbs_equal_unordered \
add_subnode_with_nops path_offset_aliases \
utilfdt_test \
- integer-expressions \
+ integer-expressions string-expressions \
subnode_iterate
LIB_TESTS = $(LIB_TESTS_L:%=$(TESTS_PREFIX)%)
diff --git a/tests/run_tests.sh b/tests/run_tests.sh
index 97e016b..44de059 100755
--- a/tests/run_tests.sh
+++ b/tests/run_tests.sh
@@ -446,6 +446,11 @@ dtc_tests () {
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 string expresisons
+ run_test string-expressions -g string-expressions.test.dts
+ run_dtc_test -I dts -O dtb -o string-expressions.test.dtb string-expressions.test.dts
+ run_test string-expressions string-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
diff --git a/tests/string-expressions.c b/tests/string-expressions.c
new file mode 100644
index 0000000..da6854f
--- /dev/null
+++ b/tests/string-expressions.c
@@ -0,0 +1,97 @@
+/*
+ * Testcase for dtc string expression support
+ *
+ * Copyright (C) 2013 David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
+ *
+ * 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 <libfdt.h>
+
+#include "tests.h"
+#include "testdata.h"
+
+struct test_expr {
+ const char *expr;
+ const char *result;
+} expr_table[] = {
+#define TE(expr, res) { #expr, (res) }
+ TE("hello", "hello"),
+ TE("hello " + "world", "hello world"),
+ TE("hello" + " " + "world", "hello world"),
+ TE("hello" * 2 + " world", "hellohello world"),
+ TE("hello " + 2 * "world", "hello worldworld"),
+ TE(("hello"), "hello"),
+ TE(0 ? "hello" : "goodbye", "goodbye"),
+ TE(1 ? "hello" : "goodbye", "hello"),
+};
+
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+
+int main(int argc, char *argv[])
+{
+ void *fdt;
+ const char *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");
+ for (i = 0; i < ARRAY_SIZE(expr_table); i++)
+ fprintf(f, "\texpression-%d = %s;\n", i,
+ expr_table[i].expr);
+ fprintf(f, "};\n");
+ fclose(f);
+ } else {
+ fdt = load_blob_arg(argc, argv);
+
+ for (i = 0; i < ARRAY_SIZE(expr_table); i++) {
+ char propname[16];
+ int len = strlen(expr_table[i].result) + 1;
+
+ sprintf(propname, "expression-%d", i);
+ res = fdt_getprop(fdt, 0, propname, &reslen);
+
+ if (reslen != len)
+ FAIL("Incorrect length for expression %s,"
+ " %d instead of %d\n",
+ expr_table[i].expr, reslen, len);
+
+ if (memcmp(res, expr_table[i].result, len) != 0)
+ FAIL("Incorrect result for expression %s,"
+ " \"%s\" instead of \"%s\"\n",
+ expr_table[i].expr, res,
+ expr_table[i].result);
+ }
+ }
+
+ PASS();
+}
--
1.8.5.3
--
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