[C++] Implement standalone Unicode encoding and decoding handling

.circleci/scripts/run-tests-cpp.sh

@@ -2,6 +2,10 @@
 
 set -euo pipefail
 
+pushd runtime/Cpp
+ctest
+popd
+
 pushd runtime-testsuite
   echo "running maven tests..."
   if [ $GROUP == "LEXER" ]; then

.github/scripts/run-tests-cpp.sh

@@ -2,14 +2,18 @@
 
 set -euo pipefail
 
-cd runtime-testsuite/
+pushd runtime/Cpp
+ctest
+popd
 
+pushd runtime-testsuite
 if [ $GROUP == "LEXER" ]; then
     mvn -q -Dgroups="org.antlr.v4.test.runtime.category.LexerTests" -Dtest=cpp.** test
 elif [ $GROUP == "PARSER" ]; then
     mvn -q -Dgroups="org.antlr.v4.test.runtime.category.ParserTests" -Dtest=cpp.** test
 elif [ $GROUP == "RECURSION" ]; then
     mvn -q -Dgroups="org.antlr.v4.test.runtime.category.LeftRecursionTests" -Dtest=cpp.** test
 else
-    mvn -q -Dtest=cpp.* test 
+    mvn -q -Dtest=cpp.* test
 fi
+popd

.travis/run-tests-cpp.sh

@@ -2,13 +2,18 @@
 
 set -euo pipefail
 
+pushd runtime/Cpp
+ctest
+popd
+
+pushd runtime-testsuite
 if [ $GROUP == "LEXER" ]; then
-    mvn -q -Dgroups="org.antlr.v4.test.runtime.category.LexerTests" -Dtest=cpp.* test 
+    mvn -q -Dgroups="org.antlr.v4.test.runtime.category.LexerTests" -Dtest=cpp.* test
 elif [ $GROUP == "PARSER" ]; then
-    mvn -q -Dgroups="org.antlr.v4.test.runtime.category.ParserTests" -Dtest=cpp.* test 
+    mvn -q -Dgroups="org.antlr.v4.test.runtime.category.ParserTests" -Dtest=cpp.* test
 elif [ $GROUP == "RECURSION" ]; then
-    mvn -q -Dgroups="org.antlr.v4.test.runtime.category.LeftRecursionTests" -Dtest=cpp.* test 
+    mvn -q -Dgroups="org.antlr.v4.test.runtime.category.LeftRecursionTests" -Dtest=cpp.* test
 else
-    mvn -q -Dtest=cpp.* test 
+    mvn -q -Dtest=cpp.* test
 fi
-
+popd

runtime/Cpp/CMakeLists.txt

@@ -1,6 +1,8 @@
 # -*- mode:cmake -*-
-cmake_minimum_required (VERSION 2.8)
-# 2.8 needed because of ExternalProject
+cmake_minimum_required (VERSION 3.14)
+# 3.14 needed because of FetchContent
+
+enable_testing()
 
 # Detect build type, fallback to release and throw a warning if use didn't specify any
 if(NOT CMAKE_BUILD_TYPE)

runtime/Cpp/deploy-macos.sh

@@ -4,18 +4,6 @@
 rm -f -R antlr4-runtime build lib 2> /dev/null
 rm antlr4-cpp-runtime-macos.zip 2> /dev/null
 
-# Get utf8 dependency.
-mkdir -p runtime/thirdparty 2> /dev/null
-pushd runtime/thirdparty
-if [ ! -d utfcpp ]
-then
-    git clone https://github.com/nemtrif/utfcpp.git utfcpp
-    pushd utfcpp
-    git checkout tags/v3.1.1
-    popd
-fi
-popd
-
 # Binaries
 xcodebuild -project runtime/antlrcpp.xcodeproj \
            -target antlr4                      \
@@ -35,9 +23,6 @@ rm -f -R antlr4-runtime
 pushd runtime/src
 find . -name '*.h' | cpio -pdm ../../antlr4-runtime
 popd
-pushd runtime/thirdparty/utfcpp/source
-find . -name '*.h' | cpio -pdm ../../../../antlr4-runtime
-popd
 
 # Zip up and clean up
 zip -r antlr4-cpp-runtime-macos.zip antlr4-runtime lib

runtime/Cpp/runtime/CMakeLists.txt

@@ -35,45 +35,35 @@ add_custom_target(make_lib_output_dir ALL
 add_dependencies(antlr4_shared make_lib_output_dir)
 add_dependencies(antlr4_static make_lib_output_dir)
 
-find_package(utf8cpp QUIET)
+include(FetchContent)
 
-set(INSTALL_utf8cpp FALSE)
+FetchContent_Declare(
+  googletest
+  URL https://github.com/google/googletest/archive/e2239ee6043f73722e7aa812a459f54a28552929.zip
+)
 
-if (utf8cpp_FOUND)
-  target_link_libraries(antlr4_shared utf8cpp)
-  target_link_libraries(antlr4_static utf8cpp)
-else()
+set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
 
-  # older utf8cpp doesn't define the package above
-  find_path(utf8cpp_HEADER utf8.h
-    PATH_SUFFIXES utf8cpp
-    )
+FetchContent_MakeAvailable(googletest)
 
-  if (utf8cpp_HEADER)
-    include_directories(${utf8cpp_HEADER})
-  else()
-    include(${CMAKE_ROOT}/Modules/ExternalProject.cmake)
-    set(THIRDPARTY_DIR ${CMAKE_BINARY_DIR}/runtime/thirdparty)
-    set(UTFCPP_DIR ${THIRDPARTY_DIR}/utfcpp)
-    ExternalProject_Add(
-      utf8cpp
-      GIT_REPOSITORY        "https://github.com/nemtrif/utfcpp"
-      GIT_TAG               "v3.1.1"
-      SOURCE_DIR            ${UTFCPP_DIR}
-      UPDATE_DISCONNECTED   1
-      CMAKE_ARGS            -DCMAKE_INSTALL_PREFIX=${UTFCPP_DIR}/install -DUTF8_TESTS=off -DUTF8_SAMPLES=off
-      STEP_TARGETS          build)
-
-    include_directories(
-      ${UTFCPP_DIR}/install/include/utf8cpp
-      ${UTFCPP_DIR}/install/include/utf8cpp/utf8
-      )
-
-    add_dependencies(antlr4_shared utf8cpp)
-    add_dependencies(antlr4_static utf8cpp)
-    set(INSTALL_utf8cpp TRUE)
-  endif()
-endif()
+file(GLOB libantlrcpp_TESTS
+  "${PROJECT_SOURCE_DIR}/runtime/tests/*.cpp"
+)
+
+add_executable(
+  antlr4_tests
+  ${libantlrcpp_TESTS}
+)
+
+target_link_libraries(
+  antlr4_tests
+  antlr4_static
+  gtest_main
+)
+
+include(GoogleTest)
+
+gtest_discover_tests(antlr4_tests)
 
 if(CMAKE_SYSTEM_NAME MATCHES "Linux")
   target_link_libraries(antlr4_shared ${UUID_LIBRARIES})
@@ -152,16 +142,3 @@ install(DIRECTORY "${PROJECT_SOURCE_DIR}/runtime/src/"
         COMPONENT dev
         FILES_MATCHING PATTERN "*.h"
         )
-
-if (INSTALL_utf8cpp)
-  install(FILES "${UTFCPP_DIR}/source/utf8.h"
-	  DESTINATION "include/antlr4-runtime")
-  install(DIRECTORY "${UTFCPP_DIR}/source/utf8"
-	  DESTINATION "include/antlr4-runtime"
-	  COMPONENT dev
-	  FILES_MATCHING PATTERN "*.h"
-	  )
-endif()
-
-
-

runtime/Cpp/runtime/src/ANTLRInputStream.cpp

@@ -9,7 +9,7 @@
 #include "misc/Interval.h"
 #include "IntStream.h"
 
-#include "support/StringUtils.h"
+#include "support/Utf8.h"
 #include "support/CPPUtils.h"
 
 #include "ANTLRInputStream.h"
@@ -35,28 +35,37 @@ ANTLRInputStream::ANTLRInputStream(std::istream &stream): ANTLRInputStream() {
   load(stream);
 }
 
-void ANTLRInputStream::load(const std::string &input) {
-  load(input.data(), input.size());
+void ANTLRInputStream::load(const std::string &input, bool lenient) {
+  load(input.data(), input.size(), lenient);
 }
 
-void ANTLRInputStream::load(const char *data, size_t length) {
+void ANTLRInputStream::load(const char *data, size_t length, bool lenient) {
   // Remove the UTF-8 BOM if present.
   const char *bom = "\xef\xbb\xbf";
-  if (length >= 3 && strncmp(data, bom, 3) == 0)
-    _data = antlrcpp::utf8_to_utf32(data + 3, data + length);
-  else
-    _data = antlrcpp::utf8_to_utf32(data, data + length);
+  if (length >= 3 && strncmp(data, bom, 3) == 0) {
+    data += 3;
+    length -= 3;
+  }
+  if (lenient) {
+    _data = Utf8::lenientDecode(std::string_view(data, length));
+  } else {
+    auto maybe_utf32 = Utf8::strictDecode(std::string_view(data, length));
+    if (!maybe_utf32.has_value()) {
+      throw IllegalArgumentException("UTF-8 string contains an illegal byte sequence");
+    }
+    _data = std::move(maybe_utf32).value();
+  }
   p = 0;
 }
 
-void ANTLRInputStream::load(std::istream &stream) {
+void ANTLRInputStream::load(std::istream &stream, bool lenient) {
   if (!stream.good() || stream.eof()) // No fail, bad or EOF.
     return;
 
   _data.clear();
 
   std::string s((std::istreambuf_iterator<char>(stream)), std::istreambuf_iterator<char>());
-  load(s.data(), s.length());
+  load(s.data(), s.length(), lenient);
 }
 
 void ANTLRInputStream::reset() {
@@ -144,7 +153,11 @@ std::string ANTLRInputStream::getText(const Interval &interval) {
     return "";
   }
 
-  return antlrcpp::utf32_to_utf8(_data.substr(start, count));
+  auto maybeUtf8 = Utf8::strictEncode(std::u32string_view(_data).substr(start, count));
+  if (!maybeUtf8.has_value()) {
+    throw IllegalArgumentException("Input stream contains invalid Unicode code points");
+  }
+  return std::move(maybeUtf8).value();
 }
 
 std::string ANTLRInputStream::getSourceName() const {
@@ -155,7 +168,11 @@ std::string ANTLRInputStream::getSourceName() const {
 }
 
 std::string ANTLRInputStream::toString() const {
-  return antlrcpp::utf32_to_utf8(_data);
+  auto maybeUtf8 = Utf8::strictEncode(_data);
+  if (!maybeUtf8.has_value()) {
+    throw IllegalArgumentException("Input stream contains invalid Unicode code points");
+  }
+  return std::move(maybeUtf8).value();
 }
 
 void ANTLRInputStream::InitializeInstanceFields() {

runtime/Cpp/runtime/src/ANTLRInputStream.h

@@ -18,7 +18,7 @@ namespace antlr4 {
   protected:
     /// The data being scanned.
     // UTF-32
-    UTF32String _data;
+    std::u32string _data;
 
     /// 0..n-1 index into string of next char </summary>
     size_t p;
@@ -34,9 +34,13 @@ namespace antlr4 {
     ANTLRInputStream(const char *data, size_t length);
     ANTLRInputStream(std::istream &stream);
 
-    virtual void load(const std::string &input);
-    virtual void load(const char *data, size_t length);
-    virtual void load(std::istream &stream);
+    virtual void load(const std::string &input, bool lenient);
+    virtual void load(const char *data, size_t length, bool lenient);
+    virtual void load(std::istream &stream, bool lenient);
+
+    virtual void load(const std::string &input) { load(input, false); }
+    virtual void load(const char *data, size_t length) { load(data, length, false); }
+    virtual void load(std::istream &stream) { load(stream, false); }
 
     /// Reset the stream so that it's in the same state it was
     /// when the object was created *except* the data array is not

runtime/Cpp/runtime/src/UnbufferedCharStream.cpp

@@ -5,7 +5,7 @@
 
 #include "misc/Interval.h"
 #include "Exceptions.h"
-#include "support/StringUtils.h"
+#include "support/Utf8.h"
 
 #include "UnbufferedCharStream.h"
 
@@ -195,7 +195,11 @@ std::string UnbufferedCharStream::getText(const misc::Interval &interval) {
   }
   // convert from absolute to local index
   size_t i = interval.a - bufferStartIndex;
-  return utf32_to_utf8(_data.substr(i, interval.length()));
+  auto maybeUtf8 = Utf8::strictEncode(std::u32string_view(_data).substr(i, interval.length()));
+  if (!maybeUtf8.has_value()) {
+    throw IllegalArgumentException("Unbuffered stream contains invalid Unicode code points");
+  }
+  return std::move(maybeUtf8).value();
 }
 
 size_t UnbufferedCharStream::getBufferStartIndex() const {