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[unsafe] Replace fs::File with libc::FILE - #135
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Oct 27, 2026
Currently we translate `FILE*` as `*mut std::fs:FILE`. This makes it difficult to translate functions such as feof and ferrror. feof and ferror both peek the internal state of the FILE object. std::fs::File doet not keep an internal state, it propagates the error right at the point of the usage, for example when performing a read or a write. On the other side, `*mut libc::FILE`, which is the direct FFI equivalent of `FILE*`, keeps the internal state, making the translation of feof and ferror easy. Another advantage of switching to `*mut libc::FILE` is that it simplifies all stdio.h rules. For example fwrites becomes a simple call to `libc::fwrite`, instead of the hand-rolled implementation that we have now for writing a buffer into `std::fs::File`.
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Currently we translate
FILE*as*mut std::fs:FILE. This makes it difficult to translate functions such as feof and ferrror.feof and ferror both peek the internal state of the FILE object. std::fs::File doet not keep an internal state, it propagates the error right at the point of the usage, for example when performing a read or a write. On the other side,
*mut libc::FILE, which is the direct FFI equivalent ofFILE*, keeps the internal state, making the translation of feof and ferror easy.Another advantage of switching to
*mut libc::FILEis that it simplifies all stdio.h rules. For example fwrites becomes a simple call tolibc::fwrite, instead of the hand-rolled implementation that we have now for writing a buffer intostd::fs::File.