diff options
| -rw-r--r-- | src/fs.cpp | 102 | ||||
| -rw-r--r-- | src/fs.h | 51 |
2 files changed, 153 insertions, 0 deletions
diff --git a/src/fs.cpp b/src/fs.cpp index df79b5e3df..a146107c4c 100644 --- a/src/fs.cpp +++ b/src/fs.cpp @@ -113,4 +113,106 @@ std::string get_filesystem_error_message(const fs::filesystem_error& e) #endif } +#ifdef WIN32 +#ifdef __GLIBCXX__ + +// reference: https://github.com/gcc-mirror/gcc/blob/gcc-7_3_0-release/libstdc%2B%2B-v3/include/std/fstream#L270 + +static std::string openmodeToStr(std::ios_base::openmode mode) +{ + switch (mode & ~std::ios_base::ate) { + case std::ios_base::out: + case std::ios_base::out | std::ios_base::trunc: + return "w"; + case std::ios_base::out | std::ios_base::app: + case std::ios_base::app: + return "a"; + case std::ios_base::in: + return "r"; + case std::ios_base::in | std::ios_base::out: + return "r+"; + case std::ios_base::in | std::ios_base::out | std::ios_base::trunc: + return "w+"; + case std::ios_base::in | std::ios_base::out | std::ios_base::app: + case std::ios_base::in | std::ios_base::app: + return "a+"; + case std::ios_base::out | std::ios_base::binary: + case std::ios_base::out | std::ios_base::trunc | std::ios_base::binary: + return "wb"; + case std::ios_base::out | std::ios_base::app | std::ios_base::binary: + case std::ios_base::app | std::ios_base::binary: + return "ab"; + case std::ios_base::in | std::ios_base::binary: + return "rb"; + case std::ios_base::in | std::ios_base::out | std::ios_base::binary: + return "r+b"; + case std::ios_base::in | std::ios_base::out | std::ios_base::trunc | std::ios_base::binary: + return "w+b"; + case std::ios_base::in | std::ios_base::out | std::ios_base::app | std::ios_base::binary: + case std::ios_base::in | std::ios_base::app | std::ios_base::binary: + return "a+b"; + default: + return std::string(); + } +} + +void ifstream::open(const fs::path& p, std::ios_base::openmode mode) +{ + close(); + m_file = fsbridge::fopen(p, openmodeToStr(mode).c_str()); + if (m_file == nullptr) { + return; + } + m_filebuf = __gnu_cxx::stdio_filebuf<char>(m_file, mode); + rdbuf(&m_filebuf); + if (mode & std::ios_base::ate) { + seekg(0, std::ios_base::end); + } +} + +void ifstream::close() +{ + if (m_file != nullptr) { + m_filebuf.close(); + fclose(m_file); + } + m_file = nullptr; +} + +void ofstream::open(const fs::path& p, std::ios_base::openmode mode) +{ + close(); + m_file = fsbridge::fopen(p, openmodeToStr(mode).c_str()); + if (m_file == nullptr) { + return; + } + m_filebuf = __gnu_cxx::stdio_filebuf<char>(m_file, mode); + rdbuf(&m_filebuf); + if (mode & std::ios_base::ate) { + seekp(0, std::ios_base::end); + } +} + +void ofstream::close() +{ + if (m_file != nullptr) { + m_filebuf.close(); + fclose(m_file); + } + m_file = nullptr; +} +#else // __GLIBCXX__ + +static_assert(sizeof(*fs::path().BOOST_FILESYSTEM_C_STR) == sizeof(wchar_t), + "Warning: This build is using boost::filesystem ofstream and ifstream " + "implementations which will fail to open paths containing multibyte " + "characters. You should delete this static_assert to ignore this warning, " + "or switch to a different C++ standard library like the Microsoft C++ " + "Standard Library (where boost uses non-standard extensions to construct " + "stream objects with wide filenames), or the GNU libstdc++ library (where " + "a more complicated workaround has been implemented above)."); + +#endif // __GLIBCXX__ +#endif // WIN32 + } // fsbridge @@ -7,6 +7,9 @@ #include <stdio.h> #include <string> +#if defined WIN32 && defined __GLIBCXX__ +#include <ext/stdio_filebuf.h> +#endif #include <boost/filesystem.hpp> #include <boost/filesystem/fstream.hpp> @@ -39,6 +42,54 @@ namespace fsbridge { }; std::string get_filesystem_error_message(const fs::filesystem_error& e); + + // GNU libstdc++ specific workaround for opening UTF-8 paths on Windows. + // + // On Windows, it is only possible to reliably access multibyte file paths through + // `wchar_t` APIs, not `char` APIs. But because the C++ standard doesn't + // require ifstream/ofstream `wchar_t` constructors, and the GNU library doesn't + // provide them (in contrast to the Microsoft C++ library, see + // https://stackoverflow.com/questions/821873/how-to-open-an-stdfstream-ofstream-or-ifstream-with-a-unicode-filename/822032#822032), + // Boost is forced to fall back to `char` constructors which may not work properly. + // + // Work around this issue by creating stream objects with `_wfopen` in + // combination with `__gnu_cxx::stdio_filebuf`. This workaround can be removed + // with an upgrade to C++17, where streams can be constructed directly from + // `std::filesystem::path` objects. + +#if defined WIN32 && defined __GLIBCXX__ + class ifstream : public std::istream + { + public: + ifstream() = default; + explicit ifstream(const fs::path& p, std::ios_base::openmode mode = std::ios_base::in) { open(p, mode); } + ~ifstream() { close(); } + void open(const fs::path& p, std::ios_base::openmode mode = std::ios_base::in); + bool is_open() { return m_filebuf.is_open(); } + void close(); + + private: + __gnu_cxx::stdio_filebuf<char> m_filebuf; + FILE* m_file = nullptr; + }; + class ofstream : public std::ostream + { + public: + ofstream() = default; + explicit ofstream(const fs::path& p, std::ios_base::openmode mode = std::ios_base::out) { open(p, mode); } + ~ofstream() { close(); } + void open(const fs::path& p, std::ios_base::openmode mode = std::ios_base::out); + bool is_open() { return m_filebuf.is_open(); } + void close(); + + private: + __gnu_cxx::stdio_filebuf<char> m_filebuf; + FILE* m_file = nullptr; + }; +#else // !(WIN32 && __GLIBCXX__) + typedef fs::ifstream ifstream; + typedef fs::ofstream ofstream; +#endif // WIN32 && __GLIBCXX__ }; #endif // BITCOIN_FS_H |