Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add preprocessor switch to disable file system include / support #4257

Closed
W4RH4WK opened this issue Dec 6, 2024 · 7 comments
Closed

Add preprocessor switch to disable file system include / support #4257

W4RH4WK opened this issue Dec 6, 2024 · 7 comments

Comments

@W4RH4WK
Copy link
Contributor

W4RH4WK commented Dec 6, 2024

This is a feature request for adding a preprocessor switch that allows one to disable the inclusion of the std::filesystem header in std.h.

The problem is that some video game console SDKs do not support std::filesystem, but ship the <filesystem> header. Therefore FMT_HAS_INCLUDE returns true, but the <filesystem> header provided by the SDK contains an #error directive breaking the build.

I'd appreciate the inclusion of a preprocessor switch (e.g. FMT_DISABLE_STD_FILESYSTEM) which can be set prior including std.h to work around this issue.

@vitaut
Copy link
Contributor

vitaut commented Dec 6, 2024

some video game console SDKs do not support std::filesystem, but ship the <filesystem> header

Could you provide some details about which SDKs do that?

@W4RH4WK
Copy link
Contributor Author

W4RH4WK commented Dec 6, 2024

Could you provide some details about which SDKs do that?

The Nintendo Switch SDK.

@vitaut
Copy link
Contributor

vitaut commented Dec 6, 2024

{fmt} already has FMT_CPP_LIB_FILESYSTEM that wraps the corresponding feature-test macro and is overridable:

fmt/include/fmt/std.h

Lines 65 to 71 in 47a66c5

#ifndef FMT_CPP_LIB_FILESYSTEM
# ifdef __cpp_lib_filesystem
# define FMT_CPP_LIB_FILESYSTEM __cpp_lib_filesystem
# else
# define FMT_CPP_LIB_FILESYSTEM 0
# endif
#endif
Does defining it to zero address your use case or is anything else missing?

@W4RH4WK
Copy link
Contributor Author

W4RH4WK commented Dec 6, 2024

The problem originates from #include <filesystem> here:

fmt/include/fmt/std.h

Lines 29 to 31 in 47a66c5

# if FMT_CPLUSPLUS >= 201703L
# if FMT_HAS_INCLUDE(<filesystem>)
# include <filesystem>

This block is above the FMT_CPP_LIB_FILESYSTEM, so defining FMT_CPP_LIB_FILESYSTEM=0 does not solve the problem.

@W4RH4WK
Copy link
Contributor Author

W4RH4WK commented Dec 6, 2024

The SDK's <filesystem> header includes these lines (as std::filesystem is not supported) which break the build. That's why I'd like to prevent fmt from even including the header.

#if defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY)
# error "The <filesystem> library is not supported since libc++ has been configured without support for a filesystem."
#endif

@vitaut
Copy link
Contributor

vitaut commented Dec 6, 2024

I think we can move the FMT_CPP_LIB_FILESYSTEM check before the <filesystem> include (it only needs <version>) and make the include conditional on it. A PR would be welcome.

@vitaut
Copy link
Contributor

vitaut commented Dec 7, 2024

Addressed by #4258.

@vitaut vitaut closed this as completed Dec 7, 2024
mtremer pushed a commit to ipfire/ipfire-2.x that referenced this issue Feb 22, 2025
- Update from version 11.0.2 to 11.1.3
- Update of rootfile
- Changelog
    11.1.3
	- Fixed compilation on GCC 9.4 (fmtlib/fmt#4313).
	- Worked around an internal compiler error when using C++20 modules with GCC
	  14.2 and earlier (fmtlib/fmt#4295).
	- Worked around a bug in GCC 6 (fmtlib/fmt#4318).
	- Fixed an issue caused by instantiating `formatter<const T>`
	  (fmtlib/fmt#4303,
	  fmtlib/fmt#4325). Thanks @timsong-cpp.
	- Fixed formatting into `std::ostreambuf_iterator` when using format string
	  compilation (fmtlib/fmt#4309,
	  fmtlib/fmt#4312). Thanks @phprus.
	- Restored a constraint on the map formatter so that it correctly reports as
	  unformattable when the element is (fmtlib/fmt#4326).
	  Thanks @timsong-cpp.
	- Reduced the size of format specs (fmtlib/fmt#4298).
	- Readded `args()` to `fmt::format_context`
	  (fmtlib/fmt#4307,
	  fmtlib/fmt#4310). Thanks @Erroneous1.
	- Fixed a bogus MSVC warning (fmtlib/fmt#4314,
	  fmtlib/fmt#4322). Thanks @ZehMatt.
	- Fixed a pedantic mode error in the CMake config
	  (fmtlib/fmt#4327). Thanks @rlalik.
    11.1.2
	- Fixed ABI compatibility with earlier 11.x versions
	  (fmtlib/fmt#4292).
	- Added `wchar_t` support to the `std::bitset` formatter
	  (fmtlib/fmt#4285,
	  fmtlib/fmt#4286,
	  fmtlib/fmt#4289,
	  fmtlib/fmt#4290). Thanks @phprus.
	- Prefixed CMake components with `fmt-` to simplify usage of {fmt} via
	  `add_subdirectory` (fmtlib/fmt#4283).
	- Updated docs for meson (fmtlib/fmt#4291).
	  Thanks @trim21.
	- Fixed a compilation error in chrono on nvcc
	  (fmtlib/fmt#4297,
	  fmtlib/fmt#4301). Thanks @breyerml.
	- Fixed various warnings
	  (fmtlib/fmt#4288,
	  fmtlib/fmt#4299). Thanks @GamesTrap and @edo9300.
    11.1.1
	- Fixed ABI compatibility with earlier 11.x versions
	  (fmtlib/fmt#4278).
	- Defined CMake components (`core` and `doc`) to allow docs to be installed
	  separately (fmtlib/fmt#4276).
	  Thanks @carlsmedstad.
    11.1.0
	- Improved C++20 module support
	  (fmtlib/fmt#4081,
	  fmtlib/fmt#4083,
	  fmtlib/fmt#4084,
	  fmtlib/fmt#4152,
	  fmtlib/fmt#4153,
	  fmtlib/fmt#4169,
	  fmtlib/fmt#4190,
	  fmtlib/fmt#4234,
	  fmtlib/fmt#4239).
	  Thanks @kamrann and @Arghnews.
	- Reduced debug (unoptimized) binary code size and the number of template
	  instantiations when passing formatting arguments. For example, unoptimized
	  binary code size for `fmt::print("{}", 42)` was reduced by ~40% on GCC and
	  ~60% on clang (x86-64).
	  GCC:
	  - Before: 161 instructions of which 105 are in reusable functions
	    ([godbolt](https://www.godbolt.org/z/s9bGoo4ze)).
	  - After: 116 instructions of which 60 are in reusable functions
	    ([godbolt](https://www.godbolt.org/z/r7GGGxMs6)).
	  Clang:
	  - Before: 310 instructions of which 251 are in reusable functions
	    ([godbolt](https://www.godbolt.org/z/Ts88b7M9o)).
	  - After: 194 instructions of which 135 are in reusable functions
	    ([godbolt](https://www.godbolt.org/z/vcrjP8ceW)).
	- Added an experimental `fmt::writer` API that can be used for writing to
	  different destinations such as files or strings
	  (fmtlib/fmt#2354).
	  For example ([godbolt](https://www.godbolt.org/z/rWoKfbP7e)):
		  ```c++
		  #include <fmt/os.h>
		  void write_text(fmt::writer w) {
		    w.print("The answer is {}.", 42);
		  }
		  int main() {
		    // Write to FILE.
		    write_text(stdout);
		    // Write to fmt::ostream.
		    auto f = fmt::output_file("myfile");
		    write_text(f);
		    // Write to std::string.
		    auto sb = fmt::string_buffer();
		    write_text(sb);
		    std::string s = sb.str();
		  }
		  ```
	- Added width and alignment support to the formatter of `std::error_code`.
	- Made `std::expected<void, E>` formattable
	  (fmtlib/fmt#4145,
	  fmtlib/fmt#4148).
	  For example ([godbolt](https://www.godbolt.org/z/hrj5c6G86)):
		  ```c++
		  fmt::print("{}", std::expected<void, int>());
		  ```
		  prints
		  ```
		  expected()
		  ```
	  Thanks @phprus.
	- Made `fmt::is_formattable<void>` SFINAE-friendly
	  (fmtlib/fmt#4147).
	- Added support for `_BitInt` formatting when using clang
	  (fmtlib/fmt#4007,
	  fmtlib/fmt#4072,
	  fmtlib/fmt#4140,
	  fmtlib/fmt#4173,
	  fmtlib/fmt#4176).
	  For example ([godbolt](https://www.godbolt.org/z/KWjbWec5z)):
		  ```c++
		  using int42 = _BitInt(42);
		  fmt::print("{}", int42(100));
		  ```
	  Thanks @Arghnews.
	- Added the `n` specifier for tuples and pairs
	  (fmtlib/fmt#4107). Thanks @someonewithpc.
	- Added support for tuple-like types to `fmt::join`
	  (fmtlib/fmt#4226,
	  fmtlib/fmt#4230). Thanks @phprus.
	- Made more types formattable at compile time
	  (fmtlib/fmt#4127). Thanks @AnthonyVH.
	- Implemented a more efficient compile-time `fmt::formatted_size`
	  (fmtlib/fmt#4102,
	  fmtlib/fmt#4103). Thanks @phprus.
	- Fixed compile-time formatting of some string types
	  (fmtlib/fmt#4065). Thanks @torshepherd.
	- Made compiled version of `fmt::format_to` work with
	  `std::back_insert_iterator<std::vector<char>>`
	  (fmtlib/fmt#4206,
	  fmtlib/fmt#4211). Thanks @phprus.
	- Added a formatter for `std::reference_wrapper`
	  (fmtlib/fmt#4163,
	  fmtlib/fmt#4164). Thanks @yfeldblum and @phprus.
	- Added experimental padding support (glibc `strftime` extension) to `%m`, `%j`
	  and `%Y` (fmtlib/fmt#4161). Thanks @KKhanhH.
	- Made microseconds formatted as `us` instead of `µs` if the Unicode support is
	  disabled (fmtlib/fmt#4088).
	- Fixed an unreleased regression in transcoding of surrogate pairs
	  (fmtlib/fmt#4094,
	  fmtlib/fmt#4095). Thanks @phprus.
	- Made `fmt::appender` satisfy `std::output_iterator` concept
	  (fmtlib/fmt#4092,
	  fmtlib/fmt#4093). Thanks @phprus.
	- Made `std::iterator_traits<fmt::appender>` standard-conforming
	  (fmtlib/fmt#4185). Thanks @CaseyCarter.
	- Made it easier to reuse `fmt::formatter<std::string_view>` for types with
	  an implicit conversion to `std::string_view`
	  (fmtlib/fmt#4036,
	  fmtlib/fmt#4055). Thanks @Arghnews.
	- Made it possible to disable `<filesystem>` use via `FMT_CPP_LIB_FILESYSTEM`
	  for compatibility with some video game console SDKs, e.g. Nintendo Switch SDK
	  (fmtlib/fmt#4257,
	  fmtlib/fmt#4258,
	  fmtlib/fmt#4259). Thanks @W4RH4WK and @phprus.
	- Fixed compatibility with platforms that use 80-bit `long double`
	  (fmtlib/fmt#4245,
	  fmtlib/fmt#4246). Thanks @jsirpoma.
	- Added support for UTF-32 code units greater than `0xFFFF` in fill
	  (fmtlib/fmt#4201).
	- Fixed handling of legacy encodings on Windows with GCC
	  (fmtlib/fmt#4162).
	- Made `fmt::to_string` take `fmt::basic_memory_buffer` by const reference
	  (fmtlib/fmt#4261,
	  fmtlib/fmt#4262). Thanks @sascha-devel.
	- Added `fmt::dynamic_format_arg_store::size`
	  (fmtlib/fmt#4270). Thanks @hannes-harnisch.
	- Removed the ability to control locale usage via an undocumented
	  `FMT_STATIC_THOUSANDS_SEPARATOR` in favor of `FMT_USE_LOCALE`.
	- Renamed `FMT_EXCEPTIONS` to `FMT_USE_EXCEPTIONS` for consistency with other
	  similar macros.
	- Improved include directory ordering to reduce the chance of including
	  incorrect headers when using multiple versions of {fmt}
	  (fmtlib/fmt#4116). Thanks @cdzhan.
	- Made it possible to compile a subset of {fmt} without the C++ runtime.
	- Improved documentation and README
	  (fmtlib/fmt#4066,
	  fmtlib/fmt#4117,
	  fmtlib/fmt#4203,
	  fmtlib/fmt#4235). Thanks @zyctree and @nikola-sh.
	- Improved the documentation generator (fmtlib/fmt#4110,
	  fmtlib/fmt#4115). Thanks @rturrado.
	- Improved CI (fmtlib/fmt#4155,
	  fmtlib/fmt#4151). Thanks @phprus.
	- Fixed various warnings and compilation issues
	  (fmtlib/fmt#2708,
	  fmtlib/fmt#4091,
	  fmtlib/fmt#4109,
	  fmtlib/fmt#4113,
	  fmtlib/fmt#4125,
	  fmtlib/fmt#4129,
	  fmtlib/fmt#4130,
	  fmtlib/fmt#4131,
	  fmtlib/fmt#4132,
	  fmtlib/fmt#4133,
	  fmtlib/fmt#4144,
	  fmtlib/fmt#4150,
	  fmtlib/fmt#4158,
	  fmtlib/fmt#4159,
	  fmtlib/fmt#4160,
	  fmtlib/fmt#4170,
	  fmtlib/fmt#4177,
	  fmtlib/fmt#4187,
	  fmtlib/fmt#4188,
	  fmtlib/fmt#4194,
	  fmtlib/fmt#4200,
	  fmtlib/fmt#4205,
	  fmtlib/fmt#4207,
	  fmtlib/fmt#4208,
	  fmtlib/fmt#4210,
	  fmtlib/fmt#4220,
	  fmtlib/fmt#4231,
	  fmtlib/fmt#4232,
	  fmtlib/fmt#4233,
	  fmtlib/fmt#4236,
	  fmtlib/fmt#4267,
	  fmtlib/fmt#4271).
	  Thanks @torsten48, @Arghnews, @tinfoilboy, @aminya, @Ottani, @zeroomega,
	  @c4v4, @kongy, @vinayyadav3016, @sergio-nsk, @phprus and @YexuanXiao.

Signed-off-by: Adolf Belka <[email protected]>
Signed-off-by: Michael Tremer <[email protected]>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

No branches or pull requests

2 participants