NodeFS fails on (folders with) named pipes

[hoodmane]

Setup:

mkdir has_named_pipe
mkfifo has_named_pipe/named_pipe

File a.c:

#include <sys/types.h>
#include <dirent.h>
#include <stdio.h>

#ifdef __EMSCRIPTEN__
#include <emscripten.h>
#endif

int count_entries(char* dirname) {
    DIR* d = opendir(dirname);
    struct dirent *ep;
    int res = 0;
    while (1) {
        ep = readdir(d);
        if (ep == NULL) {
            break;
        }
        res ++;
       printf("%s\n", ep->d_name);
    }
    return res;
}


int main() {
#ifdef __EMSCRIPTEN__
    EM_ASM({
        FS.mount(NODEFS, { root: 'has_named_pipe' }, 'has_named_pipe');
    });
#endif
    int nentries = count_entries("has_named_pipe");
    printf("nentries: %d\n", nentries);
    return 0;
}

If we compile and run with gcc we get:

$ gcc a.c
$ ./a.out
named_pipe
.
..
nentries: 3

If we compile and run with emcc we get:

$ emcc a.c  -lnodefs.js
$ node a.out.js
nentries: 0

Indeed after we see the named pipe, getdents stops reading. An error is thrown here: https://github.com/emscripten-core/emscripten/blob/main/src/library_nodefs.js?plain=1#L71 which aborts the normal handling. I think we can just ignore these entries?

Version of emscripten/emsdk:

emcc (Emscripten gcc/clang-like replacement + linker emulating GNU ld) 3.1.72-git (b2ced9de42ea8028233d7d3588c45ce837b61185)
clang version 20.0.0git (https:/github.com/llvm/llvm-project 50866e84d1da8462aeb96607bf6d9e5bbd5869c5)
Target: wasm32-unknown-emscripten
Thread model: posix

[sbc100]

I'm a little confused by the output "0" in the failing case... should that be nentries: 0 or is the zero coming from somewhere else?

[hoodmane]

Yes it should be nentries: 0, edited it.