Imported Upstream version 20220201upstream/20220201

13 files changed, 427 insertions, 265 deletions

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1dfa9e7..44a773b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -3,15 +3,21 @@ on:
   push:
     branches: [main]
 jobs:
-  build:
-    runs-on: ${{ matrix.os }}
+  build-appleclang:
+    runs-on: macos-latest
     strategy:
       fail-fast: false
       matrix:
-        os: [macos-latest, ubuntu-latest]
+        ver: [11, 14, 17, 20]
     env:
       CC: clang
       CXX: clang++
+      # Unlike GCC and upstream Clang, AppleClang still defaults to `-std=c++98`
+      # for some reason. Also, the macOS image on GitHub Actions provides wildly
+      # numbered Xcode versions. Thus, rather than varying the compiler version,
+      # we set the `-std` flag explicitly in order to vary the language version.
+      # (The other two flags are the default provided for CXXFLAGS in Makefile.)
+      CXXFLAGS: -O3 -g -std=c++${{ matrix.ver }}
     steps:
       - uses: actions/checkout@v2
       - run: make && make test
@@ -21,27 +27,27 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        tag: [9, 10, 11, 12, 13]
+        ver: [9, 10, 11, 12, 13]
     env:
-      CC: clang-${{ matrix.tag }}
-      CXX: clang++-${{ matrix.tag }}
+      CC: clang-${{ matrix.ver }}
+      CXX: clang++-${{ matrix.ver }}
     steps:
       - uses: actions/checkout@v2
-      - name: Install Clang ${{ matrix.tag }}
+      - name: Install Clang ${{ matrix.ver }}
         run: |
           wget https://apt.llvm.org/llvm.sh
           chmod +x ./llvm.sh
-          sudo ./llvm.sh ${{ matrix.tag }}
+          sudo ./llvm.sh ${{ matrix.ver }}
         shell: bash
       - run: make && make test
         shell: bash
   build-gcc:
     runs-on: ubuntu-latest
-    container: gcc:${{ matrix.tag }}
+    container: gcc:${{ matrix.ver }}
     strategy:
       fail-fast: false
       matrix:
-        tag: [4, 5, 6, 7, 8, 9, 10, 11]
+        ver: [6, 7, 8, 9, 10, 11]
     env:
       CC: gcc
       CXX: g++
diff --git a/.github/workflows/pr.yml b/.github/workflows/pr.yml
new file mode 100644
index 0000000..8ede73b
--- /dev/null
+++ b/.github/workflows/pr.yml
@@ -0,0 +1,26 @@
+name: PR
+on:
+  pull_request_target:
+    branches: [main]
+    types: [opened]
+jobs:
+  close:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/github-script@v5
+        with:
+          script: |
+            const fs = require('fs');
+            console.log(await github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number,
+              body: fs.readFileSync('CONTRIBUTING.md', { encoding: 'utf8', }),
+            }));
+            console.log(await github.rest.pulls.update({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              pull_number: context.issue.number,
+              state: 'closed',
+            }));
diff --git a/CMakeLists.txt b/CMakeLists.txt
index fcd3870..62d4995 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -6,6 +6,7 @@
 cmake_minimum_required(VERSION 3.5.1)
 
 project(RE2 CXX)
+include(CMakePackageConfigHelpers)
 include(CTest)
 include(GNUInstallDirs)
 
@@ -154,10 +155,23 @@ set(RE2_HEADERS
 
 install(FILES ${RE2_HEADERS}
         DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/re2)
-install(TARGETS re2 EXPORT re2Config
+install(TARGETS re2 EXPORT re2Targets
         ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
         LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
         RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
         INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
-install(EXPORT re2Config
+install(EXPORT re2Targets
         DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/re2 NAMESPACE re2::)
+
+configure_package_config_file(${CMAKE_CURRENT_SOURCE_DIR}/re2Config.cmake.in
+                              ${CMAKE_CURRENT_BINARY_DIR}/re2Config.cmake
+                              INSTALL_DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/re2
+                              )
+write_basic_package_version_file(${CMAKE_CURRENT_BINARY_DIR}/re2ConfigVersion.cmake
+                                 VERSION ${SONAME}.0.0
+                                 COMPATIBILITY SameMajorVersion
+                                 )
+
+install(FILES ${CMAKE_CURRENT_BINARY_DIR}/re2Config.cmake
+              ${CMAKE_CURRENT_BINARY_DIR}/re2ConfigVersion.cmake
+        DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/re2)
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 3af2b0a..882b0e2 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,2 +1,2 @@
 RE2 uses Gerrit instead of GitHub pull requests.
-See the [Contributing](https://github.com/google/re2/wiki/Contribute) wiki page.
+See the [Contribute](https://github.com/google/re2/wiki/Contribute) wiki page.
diff --git a/Makefile b/Makefile
index 2409093..c7c8145 100644
--- a/Makefile
+++ b/Makefile
@@ -17,7 +17,7 @@ CXX?=g++
 CXXFLAGS?=-O3 -g
 LDFLAGS?=
 # required
-RE2_CXXFLAGS?=-std=c++11 -pthread -Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers -I. $(CCICU) $(CCPCRE)
+RE2_CXXFLAGS?=-pthread -Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers -I. $(CCICU) $(CCPCRE)
 RE2_LDFLAGS?=-pthread $(LDICU) $(LDPCRE)
 AR?=ar
 ARFLAGS?=rsc
@@ -327,7 +327,7 @@ testinstall: static-testinstall shared-testinstall
 	@echo
 
 .PHONY: static-testinstall
-static-testinstall: CXXFLAGS:=-std=c++11 -pthread -I$(DESTDIR)$(includedir) $(CXXFLAGS)
+static-testinstall: CXXFLAGS:=-pthread -I$(DESTDIR)$(includedir) $(CXXFLAGS)
 static-testinstall: LDFLAGS:=-pthread -L$(DESTDIR)$(libdir) -l:libre2.a $(LDICU) $(LDFLAGS)
 static-testinstall:
 	@mkdir -p obj
@@ -337,21 +337,21 @@ ifeq ($(shell uname),Darwin)
 else ifeq ($(shell uname),SunOS)
 	@echo Skipping test for libre2.a on SunOS.
 else
-	(cd obj && $(CXX) testinstall.cc -o testinstall $(CXXFLAGS) $(LDFLAGS))
-	obj/testinstall
+	(cd obj && $(CXX) testinstall.cc -o static-testinstall $(CXXFLAGS) $(LDFLAGS))
+	obj/static-testinstall
 endif
 
 .PHONY: shared-testinstall
-shared-testinstall: CXXFLAGS:=-std=c++11 -pthread -I$(DESTDIR)$(includedir) $(CXXFLAGS)
+shared-testinstall: CXXFLAGS:=-pthread -I$(DESTDIR)$(includedir) $(CXXFLAGS)
 shared-testinstall: LDFLAGS:=-pthread -L$(DESTDIR)$(libdir) -lre2 $(LDICU) $(LDFLAGS)
 shared-testinstall:
 	@mkdir -p obj
 	@cp testinstall.cc obj
-	(cd obj && $(CXX) testinstall.cc -o testinstall $(CXXFLAGS) $(LDFLAGS))
+	(cd obj && $(CXX) testinstall.cc -o shared-testinstall $(CXXFLAGS) $(LDFLAGS))
 ifeq ($(shell uname),Darwin)
-	DYLD_LIBRARY_PATH="$(DESTDIR)$(libdir):$(DYLD_LIBRARY_PATH)" obj/testinstall
+	DYLD_LIBRARY_PATH="$(DESTDIR)$(libdir):$(DYLD_LIBRARY_PATH)" obj/shared-testinstall
 else
-	LD_LIBRARY_PATH="$(DESTDIR)$(libdir):$(LD_LIBRARY_PATH)" obj/testinstall
+	LD_LIBRARY_PATH="$(DESTDIR)$(libdir):$(LD_LIBRARY_PATH)" obj/shared-testinstall
 endif
 
 .PHONY: benchlog
diff --git a/re2.pc b/re2.pc
index 50fd637..a590ab8 100644
--- a/re2.pc
+++ b/re2.pc
@@ -4,5 +4,5 @@ libdir=@libdir@
 Name: re2
 Description: RE2 is a fast, safe, thread-friendly regular expression engine.
 Version: 0.0.0
-Cflags: -std=c++11 -pthread -I${includedir}
+Cflags: -pthread -I${includedir}
 Libs: -pthread -L${libdir} -lre2
diff --git a/re2/fuzzing/compiler-rt/include/fuzzer/FuzzedDataProvider.h b/re2/fuzzing/compiler-rt/include/fuzzer/FuzzedDataProvider.h
index 3e069eb..71cb427 100644
--- a/re2/fuzzing/compiler-rt/include/fuzzer/FuzzedDataProvider.h
+++ b/re2/fuzzing/compiler-rt/include/fuzzer/FuzzedDataProvider.h
@@ -14,11 +14,13 @@
 #define LLVM_FUZZER_FUZZED_DATA_PROVIDER_H_
 
 #include <algorithm>
+#include <array>
 #include <climits>
 #include <cstddef>
 #include <cstdint>
 #include <cstring>
 #include <initializer_list>
+#include <limits>
 #include <string>
 #include <type_traits>
 #include <utility>
@@ -34,272 +36,362 @@ class FuzzedDataProvider {
       : data_ptr_(data), remaining_bytes_(size) {}
   ~FuzzedDataProvider() = default;
 
-  // Returns a std::vector containing |num_bytes| of input data. If fewer than
-  // |num_bytes| of data remain, returns a shorter std::vector containing all
-  // of the data that's left. Can be used with any byte sized type, such as
-  // char, unsigned char, uint8_t, etc.
-  template <typename T> std::vector<T> ConsumeBytes(size_t num_bytes) {
-    num_bytes = std::min(num_bytes, remaining_bytes_);
-    return ConsumeBytes<T>(num_bytes, num_bytes);
-  }
+  // See the implementation below (after the class definition) for more verbose
+  // comments for each of the methods.
 
-  // Similar to |ConsumeBytes|, but also appends the terminator value at the end
-  // of the resulting vector. Useful, when a mutable null-terminated C-string is
-  // needed, for example. But that is a rare case. Better avoid it, if possible,
-  // and prefer using |ConsumeBytes| or |ConsumeBytesAsString| methods.
+  // Methods returning std::vector of bytes. These are the most popular choice
+  // when splitting fuzzing input into pieces, as every piece is put into a
+  // separate buffer (i.e. ASan would catch any under-/overflow) and the memory
+  // will be released automatically.
+  template <typename T> std::vector<T> ConsumeBytes(size_t num_bytes);
   template <typename T>
-  std::vector<T> ConsumeBytesWithTerminator(size_t num_bytes,
-                                            T terminator = 0) {
-    num_bytes = std::min(num_bytes, remaining_bytes_);
-    std::vector<T> result = ConsumeBytes<T>(num_bytes + 1, num_bytes);
-    result.back() = terminator;
-    return result;
-  }
+  std::vector<T> ConsumeBytesWithTerminator(size_t num_bytes, T terminator = 0);
+  template <typename T> std::vector<T> ConsumeRemainingBytes();
 
-  // Returns a std::string containing |num_bytes| of input data. Using this and
-  // |.c_str()| on the resulting string is the best way to get an immutable
-  // null-terminated C string. If fewer than |num_bytes| of data remain, returns
-  // a shorter std::string containing all of the data that's left.
-  std::string ConsumeBytesAsString(size_t num_bytes) {
-    static_assert(sizeof(std::string::value_type) == sizeof(uint8_t),
-                  "ConsumeBytesAsString cannot convert the data to a string.");
-
-    num_bytes = std::min(num_bytes, remaining_bytes_);
-    std::string result(
-        reinterpret_cast<const std::string::value_type *>(data_ptr_),
-        num_bytes);
-    Advance(num_bytes);
-    return result;
-  }
+  // Methods returning strings. Use only when you need a std::string or a null
+  // terminated C-string. Otherwise, prefer the methods returning std::vector.
+  std::string ConsumeBytesAsString(size_t num_bytes);
+  std::string ConsumeRandomLengthString(size_t max_length);
+  std::string ConsumeRandomLengthString();
+  std::string ConsumeRemainingBytesAsString();
 
-  // Returns a number in the range [min, max] by consuming bytes from the
-  // input data. The value might not be uniformly distributed in the given
-  // range. If there's no input data left, always returns |min|. |min| must
-  // be less than or equal to |max|.
-  template <typename T> T ConsumeIntegralInRange(T min, T max) {
-    static_assert(std::is_integral<T>::value, "An integral type is required.");
-    static_assert(sizeof(T) <= sizeof(uint64_t), "Unsupported integral type.");
+  // Methods returning integer values.
+  template <typename T> T ConsumeIntegral();
+  template <typename T> T ConsumeIntegralInRange(T min, T max);
 
-    if (min > max)
-      abort();
+  // Methods returning floating point values.
+  template <typename T> T ConsumeFloatingPoint();
+  template <typename T> T ConsumeFloatingPointInRange(T min, T max);
 
-    // Use the biggest type possible to hold the range and the result.
-    uint64_t range = static_cast<uint64_t>(max) - min;
-    uint64_t result = 0;
-    size_t offset = 0;
-
-    while (offset < sizeof(T) * CHAR_BIT && (range >> offset) > 0 &&
-           remaining_bytes_ != 0) {
-      // Pull bytes off the end of the seed data. Experimentally, this seems to
-      // allow the fuzzer to more easily explore the input space. This makes
-      // sense, since it works by modifying inputs that caused new code to run,
-      // and this data is often used to encode length of data read by
-      // |ConsumeBytes|. Separating out read lengths makes it easier modify the
-      // contents of the data that is actually read.
-      --remaining_bytes_;
-      result = (result << CHAR_BIT) | data_ptr_[remaining_bytes_];
-      offset += CHAR_BIT;
-    }
+  // 0 <= return value <= 1.
+  template <typename T> T ConsumeProbability();
 
-    // Avoid division by 0, in case |range + 1| results in overflow.
-    if (range != std::numeric_limits<decltype(range)>::max())
-      result = result % (range + 1);
+  bool ConsumeBool();
 
-    return static_cast<T>(min + result);
-  }
+  // Returns a value chosen from the given enum.
+  template <typename T> T ConsumeEnum();
 
-  // Returns a std::string of length from 0 to |max_length|. When it runs out of
-  // input data, returns what remains of the input. Designed to be more stable
-  // with respect to a fuzzer inserting characters than just picking a random
-  // length and then consuming that many bytes with |ConsumeBytes|.
-  std::string ConsumeRandomLengthString(size_t max_length) {
-    // Reads bytes from the start of |data_ptr_|. Maps "\\" to "\", and maps "\"
-    // followed by anything else to the end of the string. As a result of this
-    // logic, a fuzzer can insert characters into the string, and the string
-    // will be lengthened to include those new characters, resulting in a more
-    // stable fuzzer than picking the length of a string independently from
-    // picking its contents.
-    std::string result;
-
-    // Reserve the anticipated capaticity to prevent several reallocations.
-    result.reserve(std::min(max_length, remaining_bytes_));
-    for (size_t i = 0; i < max_length && remaining_bytes_ != 0; ++i) {
-      char next = ConvertUnsignedToSigned<char>(data_ptr_[0]);
-      Advance(1);
-      if (next == '\\' && remaining_bytes_ != 0) {
-        next = ConvertUnsignedToSigned<char>(data_ptr_[0]);
-        Advance(1);
-        if (next != '\\')
-          break;
-      }
-      result += next;
-    }
-
-    result.shrink_to_fit();
-    return result;
-  }
+  // Returns a value from the given array.
+  template <typename T, size_t size> T PickValueInArray(const T (&array)[size]);
+  template <typename T, size_t size>
+  T PickValueInArray(const std::array<T, size> &array);
+  template <typename T> T PickValueInArray(std::initializer_list<const T> list);
 
-  // Returns a std::vector containing all remaining bytes of the input data.
-  template <typename T> std::vector<T> ConsumeRemainingBytes() {
-    return ConsumeBytes<T>(remaining_bytes_);
-  }
+  // Writes data to the given destination and returns number of bytes written.
+  size_t ConsumeData(void *destination, size_t num_bytes);
 
-  // Returns a std::string containing all remaining bytes of the input data.
-  // Prefer using |ConsumeRemainingBytes| unless you actually need a std::string
-  // object.
-  std::string ConsumeRemainingBytesAsString() {
-    return ConsumeBytesAsString(remaining_bytes_);
-  }
+  // Reports the remaining bytes available for fuzzed input.
+  size_t remaining_bytes() { return remaining_bytes_; }
 
-  // Returns a number in the range [Type's min, Type's max]. The value might
-  // not be uniformly distributed in the given range. If there's no input data
-  // left, always returns |min|.
-  template <typename T> T ConsumeIntegral() {
-    return ConsumeIntegralInRange(std::numeric_limits<T>::min(),
-                                  std::numeric_limits<T>::max());
-  }
+ private:
+  FuzzedDataProvider(const FuzzedDataProvider &) = delete;
+  FuzzedDataProvider &operator=(const FuzzedDataProvider &) = delete;
 
-  // Reads one byte and returns a bool, or false when no data remains.
-  bool ConsumeBool() { return 1 & ConsumeIntegral<uint8_t>(); }
+  void CopyAndAdvance(void *destination, size_t num_bytes);
 
-  // Returns a copy of the value selected from the given fixed-size |array|.
-  template <typename T, size_t size>
-  T PickValueInArray(const T (&array)[size]) {
-    static_assert(size > 0, "The array must be non empty.");
-    return array[ConsumeIntegralInRange<size_t>(0, size - 1)];
-  }
+  void Advance(size_t num_bytes);
 
   template <typename T>
-  T PickValueInArray(std::initializer_list<const T> list) {
-    // TODO(Dor1s): switch to static_assert once C++14 is allowed.
-    if (!list.size())
-      abort();
-
-    return *(list.begin() + ConsumeIntegralInRange<size_t>(0, list.size() - 1));
-  }
-
-  // Returns an enum value. The enum must start at 0 and be contiguous. It must
-  // also contain |kMaxValue| aliased to its largest (inclusive) value. Such as:
-  // enum class Foo { SomeValue, OtherValue, kMaxValue = OtherValue };
-  template <typename T> T ConsumeEnum() {
-    static_assert(std::is_enum<T>::value, "|T| must be an enum type.");
-    return static_cast<T>(ConsumeIntegralInRange<uint32_t>(
-        0, static_cast<uint32_t>(T::kMaxValue)));
-  }
+  std::vector<T> ConsumeBytes(size_t size, size_t num_bytes);
 
-  // Returns a floating point number in the range [0.0, 1.0]. If there's no
-  // input data left, always returns 0.
-  template <typename T> T ConsumeProbability() {
-    static_assert(std::is_floating_point<T>::value,
-                  "A floating point type is required.");
+  template <typename TS, typename TU> TS ConvertUnsignedToSigned(TU value);
 
-    // Use different integral types for different floating point types in order
-    // to provide better density of the resulting values.
-    using IntegralType =
-        typename std::conditional<(sizeof(T) <= sizeof(uint32_t)), uint32_t,
-                                  uint64_t>::type;
+  const uint8_t *data_ptr_;
+  size_t remaining_bytes_;
+};
 
-    T result = static_cast<T>(ConsumeIntegral<IntegralType>());
-    result /= static_cast<T>(std::numeric_limits<IntegralType>::max());
-    return result;
+// Returns a std::vector containing |num_bytes| of input data. If fewer than
+// |num_bytes| of data remain, returns a shorter std::vector containing all
+// of the data that's left. Can be used with any byte sized type, such as
+// char, unsigned char, uint8_t, etc.
+template <typename T>
+std::vector<T> FuzzedDataProvider::ConsumeBytes(size_t num_bytes) {
+  num_bytes = std::min(num_bytes, remaining_bytes_);
+  return ConsumeBytes<T>(num_bytes, num_bytes);
+}
+
+// Similar to |ConsumeBytes|, but also appends the terminator value at the end
+// of the resulting vector. Useful, when a mutable null-terminated C-string is
+// needed, for example. But that is a rare case. Better avoid it, if possible,
+// and prefer using |ConsumeBytes| or |ConsumeBytesAsString| methods.
+template <typename T>
+std::vector<T> FuzzedDataProvider::ConsumeBytesWithTerminator(size_t num_bytes,
+                                                              T terminator) {
+  num_bytes = std::min(num_bytes, remaining_bytes_);
+  std::vector<T> result = ConsumeBytes<T>(num_bytes + 1, num_bytes);
+  result.back() = terminator;
+  return result;
+}
+
+// Returns a std::vector containing all remaining bytes of the input data.
+template <typename T>
+std::vector<T> FuzzedDataProvider::ConsumeRemainingBytes() {
+  return ConsumeBytes<T>(remaining_bytes_);
+}
+
+// Returns a std::string containing |num_bytes| of input data. Using this and
+// |.c_str()| on the resulting string is the best way to get an immutable
+// null-terminated C string. If fewer than |num_bytes| of data remain, returns
+// a shorter std::string containing all of the data that's left.
+inline std::string FuzzedDataProvider::ConsumeBytesAsString(size_t num_bytes) {
+  static_assert(sizeof(std::string::value_type) == sizeof(uint8_t),
+                "ConsumeBytesAsString cannot convert the data to a string.");
+
+  num_bytes = std::min(num_bytes, remaining_bytes_);
+  std::string result(
+      reinterpret_cast<const std::string::value_type *>(data_ptr_), num_bytes);
+  Advance(num_bytes);
+  return result;
+}
+
+// Returns a std::string of length from 0 to |max_length|. When it runs out of
+// input data, returns what remains of the input. Designed to be more stable
+// with respect to a fuzzer inserting characters than just picking a random
+// length and then consuming that many bytes with |ConsumeBytes|.
+inline std::string
+FuzzedDataProvider::ConsumeRandomLengthString(size_t max_length) {
+  // Reads bytes from the start of |data_ptr_|. Maps "\\" to "\", and maps "\"
+  // followed by anything else to the end of the string. As a result of this
+  // logic, a fuzzer can insert characters into the string, and the string
+  // will be lengthened to include those new characters, resulting in a more
+  // stable fuzzer than picking the length of a string independently from
+  // picking its contents.
+  std::string result;
+
+  // Reserve the anticipated capaticity to prevent several reallocations.
+  result.reserve(std::min(max_length, remaining_bytes_));
+  for (size_t i = 0; i < max_length && remaining_bytes_ != 0; ++i) {
+    char next = ConvertUnsignedToSigned<char>(data_ptr_[0]);
+    Advance(1);
+    if (next == '\\' && remaining_bytes_ != 0) {
+      next = ConvertUnsignedToSigned<char>(data_ptr_[0]);
+      Advance(1);
+      if (next != '\\')
+        break;
+    }
+    result += next;
   }
 
-  // Returns a floating point value in the range [Type's lowest, Type's max] by
-  // consuming bytes from the input data. If there's no input data left, always
-  // returns approximately 0.
-  template <typename T> T ConsumeFloatingPoint() {
-    return ConsumeFloatingPointInRange<T>(std::numeric_limits<T>::lowest(),
-                                          std::numeric_limits<T>::max());
+  result.shrink_to_fit();
+  return result;
+}
+
+// Returns a std::string of length from 0 to |remaining_bytes_|.
+inline std::string FuzzedDataProvider::ConsumeRandomLengthString() {
+  return ConsumeRandomLengthString(remaining_bytes_);
+}
+
+// Returns a std::string containing all remaining bytes of the input data.
+// Prefer using |ConsumeRemainingBytes| unless you actually need a std::string
+// object.
+inline std::string FuzzedDataProvider::ConsumeRemainingBytesAsString() {
+  return ConsumeBytesAsString(remaining_bytes_);
+}
+
+// Returns a number in the range [Type's min, Type's max]. The value might
+// not be uniformly distributed in the given range. If there's no input data
+// left, always returns |min|.
+template <typename T> T FuzzedDataProvider::ConsumeIntegral() {
+  return ConsumeIntegralInRange(std::numeric_limits<T>::min(),
+                                std::numeric_limits<T>::max());
+}
+
+// Returns a number in the range [min, max] by consuming bytes from the
+// input data. The value might not be uniformly distributed in the given
+// range. If there's no input data left, always returns |min|. |min| must
+// be less than or equal to |max|.
+template <typename T>
+T FuzzedDataProvider::ConsumeIntegralInRange(T min, T max) {
+  static_assert(std::is_integral<T>::value, "An integral type is required.");
+  static_assert(sizeof(T) <= sizeof(uint64_t), "Unsupported integral type.");
+
+  if (min > max)
+    abort();
+
+  // Use the biggest type possible to hold the range and the result.
+  uint64_t range = static_cast<uint64_t>(max) - min;
+  uint64_t result = 0;
+  size_t offset = 0;
+
+  while (offset < sizeof(T) * CHAR_BIT && (range >> offset) > 0 &&
+         remaining_bytes_ != 0) {
+    // Pull bytes off the end of the seed data. Experimentally, this seems to
+    // allow the fuzzer to more easily explore the input space. This makes
+    // sense, since it works by modifying inputs that caused new code to run,
+    // and this data is often used to encode length of data read by
+    // |ConsumeBytes|. Separating out read lengths makes it easier modify the
+    // contents of the data that is actually read.
+    --remaining_bytes_;
+    result = (result << CHAR_BIT) | data_ptr_[remaining_bytes_];
+    offset += CHAR_BIT;
   }
 
-  // Returns a floating point value in the given range by consuming bytes from
-  // the input data. If there's no input data left, returns |min|. Note that
-  // |min| must be less than or equal to |max|.
-  template <typename T> T ConsumeFloatingPointInRange(T min, T max) {
-    if (min > max)
-      abort();
-
-    T range = .0;
-    T result = min;
-    constexpr T zero(.0);
-    if (max > zero && min < zero && max > min + std::numeric_limits<T>::max()) {
-      // The diff |max - min| would overflow the given floating point type. Use
-      // the half of the diff as the range and consume a bool to decide whether
-      // the result is in the first of the second part of the diff.
-      range = (max / 2.0) - (min / 2.0);
-      if (ConsumeBool()) {
-        result += range;
-      }
-    } else {
-      range = max - min;
+  // Avoid division by 0, in case |range + 1| results in overflow.
+  if (range != std::numeric_limits<decltype(range)>::max())
+    result = result % (range + 1);
+
+  return static_cast<T>(min + result);
+}
+
+// Returns a floating point value in the range [Type's lowest, Type's max] by
+// consuming bytes from the input data. If there's no input data left, always
+// returns approximately 0.
+template <typename T> T FuzzedDataProvider::ConsumeFloatingPoint() {
+  return ConsumeFloatingPointInRange<T>(std::numeric_limits<T>::lowest(),
+                                        std::numeric_limits<T>::max());
+}
+
+// Returns a floating point value in the given range by consuming bytes from
+// the input data. If there's no input data left, returns |min|. Note that
+// |min| must be less than or equal to |max|.
+template <typename T>
+T FuzzedDataProvider::ConsumeFloatingPointInRange(T min, T max) {
+  if (min > max)
+    abort();
+
+  T range = .0;
+  T result = min;
+  constexpr T zero(.0);
+  if (max > zero && min < zero && max > min + std::numeric_limits<T>::max()) {
+    // The diff |max - min| would overflow the given floating point type. Use
+    // the half of the diff as the range and consume a bool to decide whether
+    // the result is in the first of the second part of the diff.
+    range = (max / 2.0) - (min / 2.0);
+    if (ConsumeBool()) {
+      result += range;
     }
-
-    return result + range * ConsumeProbability<T>();
+  } else {
+    range = max - min;
   }
 
-  // Reports the remaining bytes available for fuzzed input.
-  size_t remaining_bytes() { return remaining_bytes_; }
-
- private:
-  FuzzedDataProvider(const FuzzedDataProvider &) = delete;
-  FuzzedDataProvider &operator=(const FuzzedDataProvider &) = delete;
-
-  void Advance(size_t num_bytes) {
-    if (num_bytes > remaining_bytes_)
+  return result + range * ConsumeProbability<T>();
+}
+
+// Returns a floating point number in the range [0.0, 1.0]. If there's no
+// input data left, always returns 0.
+template <typename T> T FuzzedDataProvider::ConsumeProbability() {
+  static_assert(std::is_floating_point<T>::value,
+                "A floating point type is required.");
+
+  // Use different integral types for different floating point types in order
+  // to provide better density of the resulting values.
+  using IntegralType =
+      typename std::conditional<(sizeof(T) <= sizeof(uint32_t)), uint32_t,
+                                uint64_t>::type;
+
+  T result = static_cast<T>(ConsumeIntegral<IntegralType>());
+  result /= static_cast<T>(std::numeric_limits<IntegralType>::max());
+  return result;
+}
+
+// Reads one byte and returns a bool, or false when no data remains.
+inline bool FuzzedDataProvider::ConsumeBool() {
+  return 1 & ConsumeIntegral<uint8_t>();
+}
+
+// Returns an enum value. The enum must start at 0 and be contiguous. It must
+// also contain |kMaxValue| aliased to its largest (inclusive) value. Such as:
+// enum class Foo { SomeValue, OtherValue, kMaxValue = OtherValue };
+template <typename T> T FuzzedDataProvider::ConsumeEnum() {
+  static_assert(std::is_enum<T>::value, "|T| must be an enum type.");
+  return static_cast<T>(
+      ConsumeIntegralInRange<uint32_t>(0, static_cast<uint32_t>(T::kMaxValue)));
+}
+
+// Returns a copy of the value selected from the given fixed-size |array|.
+template <typename T, size_t size>
+T FuzzedDataProvider::PickValueInArray(const T (&array)[size]) {
+  static_assert(size > 0, "The array must be non empty.");
+  return array[ConsumeIntegralInRange<size_t>(0, size - 1)];
+}
+
+template <typename T, size_t size>
+T FuzzedDataProvider::PickValueInArray(const std::array<T, size> &array) {
+  static_assert(size > 0, "The array must be non empty.");
+  return array[ConsumeIntegralInRange<size_t>(0, size - 1)];
+}
+
+template <typename T>
+T FuzzedDataProvider::PickValueInArray(std::initializer_list<const T> list) {
+  // TODO(Dor1s): switch to static_assert once C++14 is allowed.
+  if (!list.size())
+    abort();
+
+  return *(list.begin() + ConsumeIntegralInRange<size_t>(0, list.size() - 1));
+}
+
+// Writes |num_bytes| of input data to the given destination pointer. If there
+// is not enough data left, writes all remaining bytes. Return value is the
+// number of bytes written.
+// In general, it's better to avoid using this function, but it may be useful
+// in cases when it's necessary to fill a certain buffer or object with
+// fuzzing data.
+inline size_t FuzzedDataProvider::ConsumeData(void *destination,
+                                              size_t num_bytes) {
+  num_bytes = std::min(num_bytes, remaining_bytes_);
+  CopyAndAdvance(destination, num_bytes);
+  return num_bytes;
+}
+
+// Private methods.
+inline void FuzzedDataProvider::CopyAndAdvance(void *destination,
+                                               size_t num_bytes) {
+  std::memcpy(destination, data_ptr_, num_bytes);
+  Advance(num_bytes);
+}
+
+inline void FuzzedDataProvider::Advance(size_t num_bytes) {
+  if (num_bytes > remaining_bytes_)
+    abort();
+
+  data_ptr_ += num_bytes;
+  remaining_bytes_ -= num_bytes;
+}
+
+template <typename T>
+std::vector<T> FuzzedDataProvider::ConsumeBytes(size_t size, size_t num_bytes) {
+  static_assert(sizeof(T) == sizeof(uint8_t), "Incompatible data type.");
+
+  // The point of using the size-based constructor below is to increase the
+  // odds of having a vector object with capacity being equal to the length.
+  // That part is always implementation specific, but at least both libc++ and
+  // libstdc++ allocate the requested number of bytes in that constructor,
+  // which seems to be a natural choice for other implementations as well.
+  // To increase the odds even more, we also call |shrink_to_fit| below.
+  std::vector<T> result(size);
+  if (size == 0) {
+    if (num_bytes != 0)
       abort();
-
-    data_ptr_ += num_bytes;
-    remaining_bytes_ -= num_bytes;
-  }
-
-  template <typename T>
-  std::vector<T> ConsumeBytes(size_t size, size_t num_bytes_to_consume) {
-    static_assert(sizeof(T) == sizeof(uint8_t), "Incompatible data type.");
-
-    // The point of using the size-based constructor below is to increase the
-    // odds of having a vector object with capacity being equal to the length.
-    // That part is always implementation specific, but at least both libc++ and
-    // libstdc++ allocate the requested number of bytes in that constructor,
-    // which seems to be a natural choice for other implementations as well.
-    // To increase the odds even more, we also call |shrink_to_fit| below.
-    std::vector<T> result(size);
-    if (size == 0) {
-      if (num_bytes_to_consume != 0)
-        abort();
-      return result;
-    }
-
-    std::memcpy(result.data(), data_ptr_, num_bytes_to_consume);
-    Advance(num_bytes_to_consume);
-
-    // Even though |shrink_to_fit| is also implementation specific, we expect it
-    // to provide an additional assurance in case vector's constructor allocated
-    // a buffer which is larger than the actual amount of data we put inside it.
-    result.shrink_to_fit();
     return result;
   }
 
-  template <typename TS, typename TU> TS ConvertUnsignedToSigned(TU value) {
-    static_assert(sizeof(TS) == sizeof(TU), "Incompatible data types.");
-    static_assert(!std::numeric_limits<TU>::is_signed,
-                  "Source type must be unsigned.");
-
-    // TODO(Dor1s): change to `if constexpr` once C++17 becomes mainstream.
-    if (std::numeric_limits<TS>::is_modulo)
-      return static_cast<TS>(value);
-
-    // Avoid using implementation-defined unsigned to signer conversions.
-    // To learn more, see https://stackoverflow.com/questions/13150449.
-    if (value <= std::numeric_limits<TS>::max()) {
-      return static_cast<TS>(value);
-    } else {
-      constexpr auto TS_min = std::numeric_limits<TS>::min();
-      return TS_min + static_cast<char>(value - TS_min);
-    }
+  CopyAndAdvance(result.data(), num_bytes);
+
+  // Even though |shrink_to_fit| is also implementation specific, we expect it
+  // to provide an additional assurance in case vector's constructor allocated
+  // a buffer which is larger than the actual amount of data we put inside it.
+  result.shrink_to_fit();
+  return result;
+}
+
+template <typename TS, typename TU>
+TS FuzzedDataProvider::ConvertUnsignedToSigned(TU value) {
+  static_assert(sizeof(TS) == sizeof(TU), "Incompatible data types.");
+  static_assert(!std::numeric_limits<TU>::is_signed,
+                "Source type must be unsigned.");
+
+  // TODO(Dor1s): change to `if constexpr` once C++17 becomes mainstream.
+  if (std::numeric_limits<TS>::is_modulo)
+    return static_cast<TS>(value);
+
+  // Avoid using implementation-defined unsigned to signed conversions.
+  // To learn more, see https://stackoverflow.com/questions/13150449.
+  if (value <= std::numeric_limits<TS>::max()) {
+    return static_cast<TS>(value);
+  } else {
+    constexpr auto TS_min = std::numeric_limits<TS>::min();
+    return TS_min + static_cast<TS>(value - TS_min);
   }
-
-  const uint8_t *data_ptr_;
-  size_t remaining_bytes_;
-};
+}
 
 #endif // LLVM_FUZZER_FUZZED_DATA_PROVIDER_H_
diff --git a/re2/make_unicode_casefold.py b/re2/make_unicode_casefold.py
index 0cf0d35..803adbd 100755
--- a/re2/make_unicode_casefold.py
+++ b/re2/make_unicode_casefold.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 # coding=utf-8
 #
 # Copyright 2008 The RE2 Authors.  All Rights Reserved.
diff --git a/re2/make_unicode_groups.py b/re2/make_unicode_groups.py
index 46aef40..cbe822a 100755
--- a/re2/make_unicode_groups.py
+++ b/re2/make_unicode_groups.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 # Copyright 2008 The RE2 Authors.  All Rights Reserved.
 # Use of this source code is governed by a BSD-style
 # license that can be found in the LICENSE file.
diff --git a/re2/prog.cc b/re2/prog.cc
index 55dc105..a700d35 100644
--- a/re2/prog.cc
+++ b/re2/prog.cc
@@ -611,10 +611,13 @@ void Prog::Flatten() {
     inst_count_[ip->opcode()]++;
   }
 
-  int total = 0;
+#if !defined(NDEBUG)
+  // Address a `-Wunused-but-set-variable' warning from Clang 13.x.
+  size_t total = 0;
   for (int i = 0; i < kNumInst; i++)
     total += inst_count_[i];
-  DCHECK_EQ(total, static_cast<int>(flat.size()));
+  CHECK_EQ(total, flat.size());
+#endif
 
   // Remap start_unanchored and start.
   if (start_unanchored() == 0) {
diff --git a/re2/re2.h b/re2/re2.h
index 7fd2245..df32ce3 100644
--- a/re2/re2.h
+++ b/re2/re2.h
@@ -971,7 +971,7 @@ namespace hooks {
 // As per https://github.com/google/re2/issues/325, thread_local support in
 // MinGW seems to be buggy. (FWIW, Abseil folks also avoid it.)
 #define RE2_HAVE_THREAD_LOCAL
-#if (defined(__APPLE__) && !TARGET_OS_OSX) || defined(__MINGW32__)
+#if (defined(__APPLE__) && !(defined(TARGET_OS_OSX) && TARGET_OS_OSX)) || defined(__MINGW32__)
 #undef RE2_HAVE_THREAD_LOCAL
 #endif
 
diff --git a/re2/regexp.cc b/re2/regexp.cc
index 2e1bfac..ca1318b 100644
--- a/re2/regexp.cc
+++ b/re2/regexp.cc
@@ -585,8 +585,7 @@ class NamedCapturesWalker : public Regexp::Walker<Ignored> {
       // Record first occurrence of each name.
       // (The rule is that if you have the same name
       // multiple times, only the leftmost one counts.)
-      if (map_->find(*re->name()) == map_->end())
-        (*map_)[*re->name()] = re->cap();
+      map_->insert({*re->name(), re->cap()});
     }
     return ignored;
   }
diff --git a/re2Config.cmake.in b/re2Config.cmake.in
new file mode 100644
index 0000000..7698107
--- /dev/null
+++ b/re2Config.cmake.in
@@ -0,0 +1,22 @@
+# Copyright 2022 The RE2 Authors.  All Rights Reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+@PACKAGE_INIT@
+
+include(CMakeFindDependencyMacro)
+
+set_and_check(re2_INCLUDE_DIR ${PACKAGE_PREFIX_DIR}/@CMAKE_INSTALL_INCLUDEDIR@)
+
+if(UNIX)
+  set(THREADS_PREFER_PTHREAD_FLAG ON)
+  find_dependency(Threads REQUIRED)
+endif()
+
+check_required_components(re2)
+
+if(TARGET re2::re2)
+  return()
+endif()
+
+include(${CMAKE_CURRENT_LIST_DIR}/re2Targets.cmake)