ICU-22549 Add PluralRule Fuzzer

icu4c/source/test/fuzzer/Makefile.in

@@ -45,6 +45,7 @@ FUZZER_TARGETS = \
 		 normalizer2_fuzzer \
 		 number_format_fuzzer \
 		 number_formatter_fuzzer \
+		 plurrule_fuzzer \
 		 relative_date_time_formatter_fuzzer \
 		 rule_based_break_iterator_fuzzer \
 		 timezone_create_fuzzer \

icu4c/source/test/fuzzer/plurrule_fuzzer.cpp

@@ -0,0 +1,82 @@
+// © 2023 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+
+// Fuzzer for ICU PluralRules.
+
+#include <cstring>
+
+#include "fuzzer_utils.h"
+
+#include "unicode/plurrule.h"
+#include "unicode/locid.h"
+
+
+void TestPluralRules(icu::PluralRules* pp, int32_t number, double dbl,  UErrorCode& status) {
+    if (U_FAILURE(status)) {
+        return;
+    }
+    pp->select(number);
+    pp->select(dbl);
+}
+
+void TestPluralRulesWithLocale(
+    const icu::Locale& locale, int32_t number, double dbl,  UPluralType type, UErrorCode& status) {
+    if (U_FAILURE(status)) {
+        return;
+    }
+    std::unique_ptr<icu::PluralRules> pp(icu::PluralRules::forLocale(locale, status));
+    TestPluralRules(pp.get(), number, dbl, status);
+
+    status = U_ZERO_ERROR;
+    pp.reset(icu::PluralRules::forLocale(locale, type, status));
+    TestPluralRules(pp.get(), number, dbl, status);
+
+    type = static_cast<UPluralType>(
+        static_cast<int>(type) % (static_cast<int>(UPLURAL_TYPE_COUNT)));
+
+    status = U_ZERO_ERROR;
+    pp.reset(icu::PluralRules::forLocale(locale, type, status));
+    TestPluralRules(pp.get(), number, dbl, status);
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+    uint16_t rnd;
+    int32_t number;
+    double dbl;
+    UPluralType  type;
+    if (size > 5000) {
+        size = 5000;
+    }
+    if (size < sizeof(rnd) + sizeof(number) + sizeof(dbl) + sizeof(type)) return 0;
+    icu::StringPiece fuzzData(reinterpret_cast<const char *>(data), size);
+
+    std::memcpy(&rnd, fuzzData.data(), sizeof(rnd));
+    icu::Locale locale = GetRandomLocale(rnd);
+    fuzzData.remove_prefix(sizeof(rnd));
+
+    std::memcpy(&number, fuzzData.data(), sizeof(number));
+    fuzzData.remove_prefix(sizeof(number));
+
+    std::memcpy(&dbl, fuzzData.data(), sizeof(dbl));
+    fuzzData.remove_prefix(sizeof(dbl));
+
+    std::memcpy(&type, fuzzData.data(), sizeof(type));
+    fuzzData.remove_prefix(sizeof(type));
+
+    size_t len = fuzzData.size() / sizeof(char16_t);
+    icu::UnicodeString text(false, reinterpret_cast<const char16_t*>(fuzzData.data()), len);
+
+    UErrorCode status = U_ZERO_ERROR;
+    std::unique_ptr<icu::PluralRules> pp(
+        icu::PluralRules::createRules(text, status));
+    TestPluralRules(pp.get(), number, dbl, status);
+
+    status = U_ZERO_ERROR;
+    TestPluralRulesWithLocale(locale, number, dbl, type, status);
+
+    icu::Locale locale2 = icu::Locale(fuzzData.data());
+
+    status = U_ZERO_ERROR;
+    TestPluralRulesWithLocale(locale2, number, dbl, type, status);
+    return EXIT_SUCCESS;
+}