From 11a31c90dfb1d61eafc903ce7f6b491eba9ecb4e Mon Sep 17 00:00:00 2001
From: Frank Tang <ftang@chromium.org>
Date: Mon, 20 Nov 2023 17:58:08 -0800
Subject: [PATCH] ICU-22549 Add RuleBasedBreakIterator fuzzer

---
 icu4c/source/test/fuzzer/Makefile.in          |  2 +-
 .../rule_based_break_iterator_fuzzer.cpp      | 26 +++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)
 create mode 100644 icu4c/source/test/fuzzer/rule_based_break_iterator_fuzzer.cpp

diff --git a/icu4c/source/test/fuzzer/Makefile.in b/icu4c/source/test/fuzzer/Makefile.in
index 28edbcb4963c..5f895a73950d 100644
--- a/icu4c/source/test/fuzzer/Makefile.in
+++ b/icu4c/source/test/fuzzer/Makefile.in
@@ -33,7 +33,7 @@ CPPFLAGS += -I$(srcdir) -I$(top_srcdir)/common -I$(top_srcdir)/i18n -I$(top_srcd
 DEFS += -D'U_TOPSRCDIR="$(top_srcdir)/"' -D'U_TOPBUILDDIR="$(BUILDDIR)"'
 LIBS = $(LIBCTESTFW) $(LIBICUTOOLUTIL) $(LIBICUIO) $(LIBICUI18N) $(LIBICUUC) $(DEFAULT_LIBS) $(LIB_M)
 
-FUZZER_TARGETS = break_iterator_fuzzer calendar_fuzzer collator_compare_fuzzer collator_rulebased_fuzzer converter_fuzzer date_format_fuzzer list_format_fuzzer locale_fuzzer locale_morph_fuzzer number_format_fuzzer relative_date_time_formatter_fuzzer ucasemap_fuzzer uloc_canonicalize_fuzzer uloc_for_language_tag_fuzzer uloc_get_name_fuzzer uloc_is_right_to_left_fuzzer uloc_open_keywords_fuzzer unicode_string_codepage_create_fuzzer uregex_open_fuzzer
+FUZZER_TARGETS = break_iterator_fuzzer calendar_fuzzer collator_compare_fuzzer collator_rulebased_fuzzer converter_fuzzer date_format_fuzzer list_format_fuzzer locale_fuzzer locale_morph_fuzzer number_format_fuzzer relative_date_time_formatter_fuzzer rule_based_break_iterator_fuzzer ucasemap_fuzzer uloc_canonicalize_fuzzer uloc_for_language_tag_fuzzer uloc_get_name_fuzzer uloc_is_right_to_left_fuzzer uloc_open_keywords_fuzzer unicode_string_codepage_create_fuzzer uregex_open_fuzzer
 
 OBJECTS = $(FUZZER_TARGETS:%=%.o)
 OBJECTS += fuzzer_driver.o locale_util.o
diff --git a/icu4c/source/test/fuzzer/rule_based_break_iterator_fuzzer.cpp b/icu4c/source/test/fuzzer/rule_based_break_iterator_fuzzer.cpp
new file mode 100644
index 000000000000..7344ecb7d99e
--- /dev/null
+++ b/icu4c/source/test/fuzzer/rule_based_break_iterator_fuzzer.cpp
@@ -0,0 +1,26 @@
+// © 2023 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+
+#include <cstring>
+
+#include "fuzzer_utils.h"
+#include "unicode/localpointer.h"
+#include "unicode/locid.h"
+#include "unicode/rbbi.h"
+
+IcuEnvironment* env = new IcuEnvironment();
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  UErrorCode status = U_ZERO_ERROR;
+
+  size_t unistr_size = size/2;
+  std::unique_ptr<char16_t[]> fuzzbuff(new char16_t[unistr_size]);
+  std::memcpy(fuzzbuff.get(), data, unistr_size * 2);
+  icu::UnicodeString fuzzstr(false, fuzzbuff.get(), unistr_size);
+
+  UParseError parse;
+  icu::LocalPointer<icu::RuleBasedBreakIterator> brk(
+      new icu::RuleBasedBreakIterator(fuzzstr, parse, status));
+
+  return 0;
+}