ICU-23095 Add fuzzer for DecimalFormatSymbols

icu4c/source/test/fuzzer/Makefile.in

@@ -40,6 +40,7 @@ FUZZER_TARGETS = \
 		 collator_rulebased_fuzzer \
 		 converter_fuzzer date_format_fuzzer \
 		 date_time_pattern_generator_fuzzer \
+		 decimal_format_symbols_fuzzer \
 		 dtfmtsym_fuzzer \
 		 list_format_fuzzer locale_fuzzer \
 		 locale_morph_fuzzer \

icu4c/source/test/fuzzer/decimal_format_symbols_fuzzer.cpp

@@ -0,0 +1,95 @@
+// © 2025 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+
+// Fuzzer for DecimalFormatSymbols::DecimalFormatSymbols.
+
+#include <cstring>
+#include <stddef.h>
+#include <stdint.h>
+#include <string>
+#include <memory>
+#include "fuzzer_utils.h"
+#include "unicode/dcfmtsym.h"
+#include "unicode/unum.h"
+#include "uassert.h"
+
+IcuEnvironment* env = new IcuEnvironment();
+
+void testMethods(
+    const icu::DecimalFormatSymbols& dfs,
+    icu::DecimalFormatSymbols::ENumberFormatSymbol symbol,
+    UCurrencySpacing spacing,
+    int32_t digit) {
+  dfs.getLocale();
+  dfs.getSymbol(symbol);
+  dfs.getConstSymbol(symbol);
+  dfs.getCurrencyPattern();
+  dfs.getNumberingSystemName();
+  dfs.isCustomCurrencySymbol();
+  dfs.isCustomIntlCurrencySymbol();
+  dfs.getCodePointZero();
+  dfs.getConstDigitSymbol(digit);
+  UErrorCode status = U_ZERO_ERROR;
+  dfs.getPatternForCurrencySpacing(spacing, true, status);
+  dfs.getPatternForCurrencySpacing(spacing, false, status);
+
+}
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  UErrorCode status = U_ZERO_ERROR;
+  if (size < sizeof(uint16_t)) {
+    return 0;
+  }
+  uint16_t rnd = *(reinterpret_cast<const uint16_t *>(data));
+  const icu::Locale& locale = GetRandomLocale(rnd);
+  data = data + sizeof(uint16_t);
+  size = size - sizeof(uint16_t);
+
+  if (size < sizeof(uint16_t)) {
+    return 0;
+  }
+  uint16_t rnd2 = *(reinterpret_cast<const uint16_t *>(data));
+  std::unique_ptr<const icu::NumberingSystem> ns(CreateRandomNumberingSystem(rnd2, status));
+  U_ASSERT(U_SUCCESS(status));
+  data = data + sizeof(uint16_t);
+  size = size - sizeof(uint16_t);
+
+  if (size < sizeof(int32_t)) {
+    return 0;
+  }
+  int32_t digit = *(reinterpret_cast<const int32_t *>(data));
+  data = data + sizeof(int32_t);
+  size = size - sizeof(int32_t);
+
+  if (size < sizeof(uint8_t)) {
+    return 0;
+  }
+  icu::DecimalFormatSymbols::ENumberFormatSymbol symbol =
+      static_cast<icu::DecimalFormatSymbols::ENumberFormatSymbol>(
+      *data % icu::DecimalFormatSymbols::ENumberFormatSymbol::kFormatSymbolCount);
+  data = data + sizeof(uint8_t);
+  size = size - sizeof(uint8_t);
+
+  if (size < sizeof(uint8_t)) {
+    return 0;
+  }
+  UCurrencySpacing spacing =
+      static_cast<UCurrencySpacing>(
+      *data % UCurrencySpacing::UNUM_CURRENCY_SPACING_COUNT);
+  data = data + sizeof(uint8_t);
+  size = size - sizeof(uint8_t);
+
+  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);
+  icu::DecimalFormatSymbols dfs1(locale, status);
+  U_ASSERT(U_SUCCESS(status));
+  testMethods(dfs1, symbol, spacing, digit);
+
+  icu::DecimalFormatSymbols dfs2(locale, *ns, status);
+  U_ASSERT(U_SUCCESS(status));
+  testMethods(dfs2, symbol, spacing, digit);
+
+  return 0;
+}

icu4c/source/test/fuzzer/fuzzer_utils.h

@@ -7,6 +7,8 @@
 #include <assert.h>
 
 #include "unicode/locid.h"
+#include "unicode/numsys.h"
+#include "unicode/strenum.h"
 
 struct IcuEnvironment {
   IcuEnvironment() {
@@ -21,4 +23,20 @@ const icu::Locale& GetRandomLocale(uint16_t rnd) {
   return locales[rnd % num_locales];
 }
 
+const icu::NumberingSystem* CreateRandomNumberingSystem(uint16_t rnd, UErrorCode &status) {
+  std::unique_ptr<icu::StringEnumeration> se(icu::NumberingSystem::getAvailableNames(status));
+  if (U_FAILURE(status)) return nullptr;
+  int32_t count = se->count(status);
+  if (U_FAILURE(status)) return nullptr;
+  int32_t index = rnd % count;
+  se->reset(status);
+  for (int32_t i = 0; i < index - 1; i++, se->next(nullptr, status)) {
+      // empty
+  }
+  const char* name = se->next(nullptr, status);
+  if (U_FAILURE(status)) return nullptr;
+  return icu::NumberingSystem::createInstanceByName(name, status);
+}
+
+
 #endif  // FUZZER_UTILS_H_