| 1 | #ifdef __wasilibc_unmodified_upstream // WASI has no syscall, dup |
| 2 | #include "stdio_impl.h" |
| 3 | #else |
| 4 | #include <wasi/libc.h> |
| 5 | #endif |
| 6 | #include <fcntl.h> |
| 7 | #include <unistd.h> |
| 8 | #ifdef __wasilibc_unmodified_upstream // WASI has no syscall, dup |
| 9 | #else |
| 10 | // Move this below fcntl.h and unistd.h so that the __syscall macro doesn't |
| 11 | // cause trouble. |
| 12 | #include "stdio_impl.h" |
| 13 | #endif |
| 14 | |
| 15 | /* The basic idea of this implementation is to open a new FILE, |
| 16 | * hack the necessary parts of the new FILE into the old one, then |
| 17 | * close the new FILE. */ |
| 18 | |
| 19 | /* Locking IS necessary because another thread may provably hold the |
| 20 | * lock, via flockfile or otherwise, when freopen is called, and in that |
| 21 | * case, freopen cannot act until the lock is released. */ |
| 22 | |
| 23 | FILE *freopen(const char *restrict filename, const char *restrict mode, FILE *restrict f) |
| 24 | { |
| 25 | int fl = __fmodeflags(mode); |
| 26 | FILE *f2; |
| 27 | |
| 28 | FLOCK(f); |
| 29 | |
| 30 | fflush(f); |
| 31 | |
| 32 | if (!filename) { |
| 33 | if (fl&O_CLOEXEC) |
| 34 | #ifdef __wasilibc_unmodified_upstream // WASI has no syscall |
| 35 | __syscall(SYS_fcntl, f->fd, F_SETFD, FD_CLOEXEC); |
| 36 | #else |
| 37 | fcntl(f->fd, F_SETFD, FD_CLOEXEC); |
| 38 | #endif |
| 39 | fl &= ~(O_CREAT|O_EXCL|O_CLOEXEC); |
| 40 | #ifdef __wasilibc_unmodified_upstream // WASI has no syscall |
| 41 | if (syscall(SYS_fcntl, f->fd, F_SETFL, fl) < 0) |
| 42 | #else |
| 43 | if (fcntl(f->fd, F_SETFL, fl) < 0) |
| 44 | #endif |
| 45 | goto fail; |
| 46 | } else { |
| 47 | f2 = fopen(filename, mode); |
| 48 | if (!f2) goto fail; |
| 49 | if (f2->fd == f->fd) f2->fd = -1; /* avoid closing in fclose */ |
| 50 | #ifdef __wasilibc_unmodified_upstream // WASI has no dup |
| 51 | else if (__dup3(f2->fd, f->fd, fl&O_CLOEXEC)<0) goto fail2; |
| 52 | #else |
| 53 | // WASI doesn't have dup3, but does have a way to renumber |
| 54 | // an existing file descriptor. |
| 55 | else { |
| 56 | if (__wasilibc_fd_renumber(f2->fd, f->fd)<0) goto fail2; |
| 57 | f2->fd = -1; /* avoid closing in fclose */ |
| 58 | } |
| 59 | #endif |
| 60 | |
| 61 | f->flags = (f->flags & F_PERM) | f2->flags; |
| 62 | f->read = f2->read; |
| 63 | f->write = f2->write; |
| 64 | f->seek = f2->seek; |
| 65 | f->close = f2->close; |
| 66 | |
| 67 | fclose(f2); |
| 68 | } |
| 69 | |
| 70 | f->mode = 0; |
| 71 | f->locale = 0; |
| 72 | FUNLOCK(f); |
| 73 | return f; |
| 74 | |
| 75 | fail2: |
| 76 | fclose(f2); |
| 77 | fail: |
| 78 | fclose(f); |
| 79 | return NULL; |
| 80 | } |
| 81 | |
| 82 | weak_alias(freopen, freopen64); |