emscripten-core/emscripten

FS permission handling seems odd

Open

#14.866 geöffnet am 14. Aug. 2021

Auf GitHub ansehen
 (2 Kommentare) (0 Reaktionen) (0 zugewiesene Personen)C++ (3.519 Forks)batch import
help wanted

Repository-Metriken

Stars
 (27.361 Stars)
PR-Merge-Metriken
 (Durchschn. Merge 19T 10h) (147 gemergte PRs in 30 T)

Beschreibung

The following test code runs perfectly fine when compiled with clang and ran, but when ran with emscripten the ftruncate operation throws a Permission error instead of going through as expected.

#include <assert.h>
#include <stdio.h>

#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>

int main() {
  int fd = 0;
  char filename[] = "XXXXXX";

  // Test
  assert((fd = mkstemp(filename)) >= 0);
  assert(chmod(filename, 0) >= 0);
  assert(ftruncate(fd, 69) >= 0);

  // Cleanup
  assert(close(fd) >= 0);
  assert(remove(filename) >= 0);

  printf("ok\n");
  return 0;
}

Ran with

  • clang main.c -o testfs && ./testfs
  • emcc main.c -s ENVIRONMENT=node -s MAIN_MODULE -o out.js && node out.js

Current behavior

Clang build prints ok, emcc build fails (assertion error at ftruncate)

Expected behavior

Both should print "ok"

Environment

OS: Arch Linux clang version 12.0.1 emscripten version 2.0.26 (with clang 13.0.0) node version 16.4.2

Contributor Guide