2023-09-04 14:13:38

by James Clark

[permalink] [raw]
Subject: [PATCH v2 3/7] perf util: Add a function for replacing characters in a string

It finds all occurrences of a single character and replaces them with
a multi character string. This will be used in a test in a following
commit.

Reviewed-by: Ian Rogers <[email protected]>
Signed-off-by: James Clark <[email protected]>
---
tools/perf/tests/Build | 1 +
tools/perf/tests/builtin-test.c | 1 +
tools/perf/tests/tests.h | 1 +
tools/perf/tests/util.c | 31 +++++++++++++++++++++
tools/perf/util/string.c | 48 +++++++++++++++++++++++++++++++++
tools/perf/util/string2.h | 1 +
6 files changed, 83 insertions(+)
create mode 100644 tools/perf/tests/util.c

diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build
index 63d5e6d5f165..2b45ffa462a6 100644
--- a/tools/perf/tests/Build
+++ b/tools/perf/tests/Build
@@ -66,6 +66,7 @@ perf-y += dlfilter-test.o
perf-y += sigtrap.o
perf-y += event_groups.o
perf-y += symbols.o
+perf-y += util.o

ifeq ($(SRCARCH),$(filter $(SRCARCH),x86 arm arm64 powerpc))
perf-$(CONFIG_DWARF_UNWIND) += dwarf-unwind.o
diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 0ad18cf6dd22..cb6f1dd00dc4 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -123,6 +123,7 @@ static struct test_suite *generic_tests[] = {
&suite__sigtrap,
&suite__event_groups,
&suite__symbols,
+ &suite__util,
NULL,
};

diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index f33cfc3c19a4..b394f3ac2d66 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -145,6 +145,7 @@ DECLARE_SUITE(dlfilter);
DECLARE_SUITE(sigtrap);
DECLARE_SUITE(event_groups);
DECLARE_SUITE(symbols);
+DECLARE_SUITE(util);

/*
* PowerPC and S390 do not support creation of instruction breakpoints using the
diff --git a/tools/perf/tests/util.c b/tools/perf/tests/util.c
new file mode 100644
index 000000000000..6366db5cbf8c
--- /dev/null
+++ b/tools/perf/tests/util.c
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "tests.h"
+#include "util/debug.h"
+
+#include <linux/compiler.h>
+#include <stdlib.h>
+#include <string2.h>
+
+static int test_strreplace(char needle, const char *haystack,
+ const char *replace, const char *expected)
+{
+ char *new = strreplace_chars(needle, haystack, replace);
+ int ret = strcmp(new, expected);
+
+ free(new);
+ return ret == 0;
+}
+
+static int test__util(struct test_suite *t __maybe_unused, int subtest __maybe_unused)
+{
+ TEST_ASSERT_VAL("empty string", test_strreplace(' ', "", "123", ""));
+ TEST_ASSERT_VAL("no match", test_strreplace('5', "123", "4", "123"));
+ TEST_ASSERT_VAL("replace 1", test_strreplace('3', "123", "4", "124"));
+ TEST_ASSERT_VAL("replace 2", test_strreplace('a', "abcabc", "ef", "efbcefbc"));
+ TEST_ASSERT_VAL("replace long", test_strreplace('a', "abcabc", "longlong",
+ "longlongbclonglongbc"));
+
+ return 0;
+}
+
+DEFINE_SUITE("util", util);
diff --git a/tools/perf/util/string.c b/tools/perf/util/string.c
index cf05b0b56c57..116a642ad99d 100644
--- a/tools/perf/util/string.c
+++ b/tools/perf/util/string.c
@@ -301,3 +301,51 @@ unsigned int hex(char c)
return c - 'a' + 10;
return c - 'A' + 10;
}
+
+/*
+ * Replace all occurrences of character 'needle' in string 'haystack' with
+ * string 'replace'
+ *
+ * The new string could be longer so a new string is returned which must be
+ * freed.
+ */
+char *strreplace_chars(char needle, const char *haystack, const char *replace)
+{
+ int replace_len = strlen(replace);
+ char *new_s, *to;
+ const char *loc = strchr(haystack, needle);
+ const char *from = haystack;
+ int num = 0;
+
+ /* Count occurrences */
+ while (loc) {
+ loc = strchr(loc + 1, needle);
+ num++;
+ }
+
+ /* Allocate enough space for replacements and reset first location */
+ new_s = malloc(strlen(haystack) + (num * (replace_len - 1) + 1));
+ if (!new_s)
+ return NULL;
+ loc = strchr(haystack, needle);
+ to = new_s;
+
+ while (loc) {
+ /* Copy original string up to found char and update positions */
+ memcpy(to, from, 1 + loc - from);
+ to += loc - from;
+ from = loc + 1;
+
+ /* Copy replacement string and update positions */
+ memcpy(to, replace, replace_len);
+ to += replace_len;
+
+ /* needle next occurrence or end of string */
+ loc = strchr(from, needle);
+ }
+
+ /* Copy any remaining chars + null */
+ strcpy(to, from);
+
+ return new_s;
+}
diff --git a/tools/perf/util/string2.h b/tools/perf/util/string2.h
index 56c30fef9682..52cb8ba057c7 100644
--- a/tools/perf/util/string2.h
+++ b/tools/perf/util/string2.h
@@ -39,5 +39,6 @@ char *strpbrk_esc(char *str, const char *stopset);
char *strdup_esc(const char *str);

unsigned int hex(char c);
+char *strreplace_chars(char needle, const char *haystack, const char *replace);

#endif /* PERF_STRING_H */
--
2.34.1