Fix --cpp_std values: c++0x, c++11, c++17

google · aardappel · Dec 23, 2019 · Dec 8, 2019 · Dec 16, 2019 · Dec 17, 2019
commit c17e1ec15b8cd74344ad94607b4b053848a92b05
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -36,7 +36,7 @@ option(FLATBUFFERS_BUILD_CPP17
        Requirements: Clang6, GCC7, MSVC2017 (_MSC_VER >= 1914)  or higher."
        OFF)
 option(FLATBUFFERS_BUILD_LEGACY
-       "Run C++ code generator with '--cpp-std legacy' switch."
+       "Run C++ code generator with '--cpp-std c++0x' switch."
        OFF)
 
 if(NOT FLATBUFFERS_BUILD_FLATC AND FLATBUFFERS_BUILD_TESTS)
@@ -342,7 +342,7 @@ endif()
 
 function(compile_flatbuffers_schema_to_cpp_opt SRC_FBS OPT)
   if(FLATBUFFERS_BUILD_LEGACY)
-    set(OPT ${OPT};--cpp-std legacy)
+    set(OPT ${OPT};--cpp-std c++0x)
   endif()
   message(STATUS "Add the code-generation command for the `${SRC_FBS}` schema with '${OPT}'")
   get_filename_component(SRC_FBS_DIR ${SRC_FBS} PATH)

diff --git a/appveyor.yml b/appveyor.yml
@@ -16,7 +16,7 @@ environment:
   matrix:
     - CMAKE_VS_VERSION: "10 2010"
       CMAKE_OPTIONS: "-DFLATBUFFERS_BUILD_LEGACY=1"
-      CPP_TEST_OPTIONS: "--std-cpp legacy"
+      CPP_TEST_OPTIONS: "--std-cpp c++0x"
       MONSTER_EXTRA: "skip"
 
     - CMAKE_VS_VERSION: "12 2013"

diff --git a/docs/source/Compiler.md b/docs/source/Compiler.md
@@ -134,8 +134,8 @@ Additional options:
 
 -   `--cpp-std CPP_STD` : Generate a C++ code using features of selected C++ standard.
      Supported `CPP_STD` values:
-    * `c++` - use a standard code generation rules;
-    * `legacy` - generate code compatible with old compilers (VS2010).
+    * `c++0x` - generate code compatible with old compilers (VS2010).
+    * `c++11` - use C++11 code generator (default);
 
 -   `--object-prefix` : Customise class prefix for C++ object-based API.
 

diff --git a/include/flatbuffers/flatc.h b/include/flatbuffers/flatc.h
@@ -27,15 +27,8 @@
 
 namespace flatbuffers {
 
-class FlatCompilerLogger {
-  FlatCompilerLogger() {}
-public:
-  // There is no way to notify about an error from a code-generator
-  // except `assert` call.
-  // TODO: re-design interface to code generators.
-  static void Warn(const std::string &warn);
-  static void Error(const std::string &err);
-};
+extern void LogCompilerWarn(const std::string &warn);
+extern void LogCompilerError(const std::string &err);
 
 class FlatCompiler {
  public:

diff --git a/reflection/generate_code.bat b/reflection/generate_code.bat
@@ -15,4 +15,4 @@
 set buildtype=Release
 if "%1"=="-b" set buildtype=%2
 
-..\%buildtype%\flatc.exe --cpp --cpp-std legacy --no-prefix -o ../include/flatbuffers reflection.fbs || exit /b 1
+..\%buildtype%\flatc.exe --cpp --cpp-std c++0x --no-prefix -o ../include/flatbuffers reflection.fbs || exit /b 1
diff --git a/reflection/generate_code.sh b/reflection/generate_code.sh
@@ -15,4 +15,4 @@
 # limitations under the License.
 set -e
 
-../flatc -c --cpp-std legacy --no-prefix -o ../include/flatbuffers reflection.fbs
+../flatc -c --cpp-std c++0x --no-prefix -o ../include/flatbuffers reflection.fbs
diff --git a/src/flatc.cpp b/src/flatc.cpp
@@ -118,9 +118,9 @@ std::string FlatCompiler::GetUsageString(const char *program_name) const {
     "                         from Flatbuffers, but (char* + length).\n"
     "  --cpp-std CPP_STD      Generate a C++ code using features of selected C++ standard.\n"
     "                         Supported CPP_STD values:\n"
-    "                          * 'legacy' - generate code compatible with old compilers.\n"
-    "                          * 'c++' - use default code generation rules (default);\n"
-    "                          * 'c++17' - use C++17 features in generated code (experemental);\n"
+    "                          * 'c++0x' - generate code compatible with old compilers;\n"
+    "                          * 'c++11' - use C++11 code generator (default);\n"
+    "                          * 'c++17' - use C++17 features in generated code (experimental).\n"
     "  --object-prefix        Customise class prefix for C++ object-based API.\n"
     "  --object-suffix        Customise class suffix for C++ object-based API.\n"
     "                         Default value is \"T\".\n"

diff --git a/src/flatc_main.cpp b/src/flatc_main.cpp
@@ -35,12 +35,12 @@ static void Error(const flatbuffers::FlatCompiler *flatc,
 }
 
 namespace flatbuffers {
-void FlatCompilerLogger::Warn(const std::string &warn) {
-  ::Warn(static_cast<const flatbuffers::FlatCompiler *>(nullptr), warn, true);
+void LogCompilerWarn(const std::string &warn) {
+  Warn(static_cast<const flatbuffers::FlatCompiler *>(nullptr), warn, true);
 }
-void FlatCompilerLogger::Error(const std::string &err) {
-  ::Error(static_cast<const flatbuffers::FlatCompiler *>(nullptr), err, false,
-          true);
+void LogCompilerError(const std::string &err) {
+  Error(static_cast<const flatbuffers::FlatCompiler *>(nullptr), err, false,
+        true);
 }
 }  // namespace flatbuffers
 

diff --git a/src/idl_gen_cpp.cpp b/src/idl_gen_cpp.cpp
@@ -58,12 +58,12 @@ namespace cpp {
 // Extension of IDLOptions for cpp-generator.
 struct IDLOptionsCpp : public IDLOptions {
   // All fields start with 'g_' prefix to distinguish from the base IDLOptions.
-  int g_cpp_std;  // base version of C++ standard (0, 17)
-  bool g_only_fixed_enums;
+  int g_cpp_std;  // Base version of C++ standard (0, 11, 17).
+  bool g_only_fixed_enums; // Generate underlaying type for all enums.
   // clang-format off
   IDLOptionsCpp(const IDLOptions &opts)
       : IDLOptions(opts),
-        g_cpp_std(0),
+        g_cpp_std(11),
         g_only_fixed_enums(true)
       {}
   // clang-format on
@@ -728,7 +728,7 @@ class CppGenerator : public BaseGenerator {
       auto element_type = type.VectorType();
       // Check if enum arrays are used in C++ without specifying --scoped-enums
       if (IsEnum(element_type) && !opts_.g_only_fixed_enums) {
-        FlatCompilerLogger::Error(
+        LogCompilerError(
             "--scoped-enums must be enabled to use enum arrays in C++");
         FLATBUFFERS_ASSERT(true);
       }
@@ -2985,19 +2985,23 @@ bool GenerateCPP(const Parser &parser, const std::string &path,
   cpp::IDLOptionsCpp opts(parser.opts);
   // The '--cpp_std' argument could be extended (like ASAN):
   // Example: "flatc --cpp_std c++17:option1:option2".
-  if (opts.cpp_std.empty() || opts.cpp_std == "c++") {
-    // Use a `standard` code generator.
-  } else if (opts.cpp_std == "c++17") {
+  auto cpp_std = opts.cpp_std;
+  std::transform(cpp_std.begin(), cpp_std.end(), cpp_std.begin(), ToUpper);
+  if (cpp_std.empty() || cpp_std == "C++11") {
+    // Use the standard C++11 code generator.
+    opts.g_cpp_std = 11;
+  } else if (cpp_std == "C++0X") {
+    opts.g_cpp_std = 0;
+    opts.g_only_fixed_enums = false;
+  } else if (cpp_std == "C++17") {
     opts.g_cpp_std = 17;
     // With c++17 generate strong enums only.
     opts.scoped_enums = true;
+    // By default, prefixed_enums==true, reset it.
     opts.prefixed_enums = false;
-  } else if (opts.cpp_std == "legacy") {
-    opts.g_cpp_std = -1;
-    opts.g_only_fixed_enums = false;
   } else {
-    FlatCompilerLogger::Error("Unknown value of the '--cpp-std' switch: " +
-                              opts.cpp_std);
+    LogCompilerError("Unknown value of the '--cpp-std' switch: " +
+                     opts.cpp_std);
     return false;
   }
   // The opts.scoped_enums has priority.

diff --git a/tests/generate_code.bat b/tests/generate_code.bat
@@ -19,7 +19,7 @@ if "%1"=="-b" set buildtype=%2
 
 set commandline=%*
 set TEST_CPP_FLAGS=
-if NOT "%commandline%"=="%commandline:--cpp-std legacy=%" set TEST_CPP_FLAGS=--cpp-std legacy %TEST_CPP_FLAGS%
+if NOT "%commandline%"=="%commandline:--cpp-std c++0x=%" set TEST_CPP_FLAGS=--cpp-std c++0x %TEST_CPP_FLAGS%
 
 set TEST_CPP_FLAGS=--gen-compare --cpp-ptr-type flatbuffers::unique_ptr %TEST_CPP_FLAGS%
 set TEST_BASE_FLAGS=--reflect-names --gen-mutable --gen-object-api

diff --git a/tests/generate_code.sh b/tests/generate_code.sh
@@ -17,8 +17,8 @@ set -e
 
 commandline="'$*'"
 TEST_CPP_FLAGS=
-if [[ $commandline == *"--cpp-std legacy"* ]]; then
-  TEST_CPP_FLAGS="--cpp-std legacy $TEST_CPP_FLAGS"
+if [[ $commandline == *"--cpp-std c++0x"* ]]; then
+  TEST_CPP_FLAGS="--cpp-std c++0x $TEST_CPP_FLAGS"
 fi
 
 TEST_CPP_FLAGS="--gen-compare --cpp-ptr-type flatbuffers::unique_ptr $TEST_CPP_FLAGS"
@@ -49,4 +49,4 @@ cd ../samples
 ../flatc --cpp --lobster $TEST_BASE_FLAGS $TEST_CPP_FLAGS monster.fbs
 ../flatc -b --schema --bfbs-comments --bfbs-builtins monster.fbs
 cd ../reflection
-./generate_code.sh --cpp-std legacy
+./generate_code.sh --cpp-std c++0x