1 files changed, 141 insertions, 0 deletions
diff --git a/libc-bottom-half/sources/at_fdcwd.c b/libc-bottom-half/sources/at_fdcwd.c
new file mode 100644
index 0000000..c83797d
--- /dev/null
+++ b/libc-bottom-half/sources/at_fdcwd.c
@@ -0,0 +1,141 @@
+// Handle AT_FDCWD and absolute paths for the *at functions.
+//
+// In the case of an AT_FDCWD file descriptor or an absolute path, call the
+// corresponding non-`at` function. This will send it through the libpreopen
+// wrappers to convert the path into a directory file descriptor and relative
+// path before translating it into the corresponding `__wasilibc_nocwd_*at`
+// function, which then calls the appropriate WASI function.
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <wasi/libc.h>
+#include <wasi/libc-nocwd.h>
+
+// If the platform doesn't define O_TMPFILE, we don't need to worry about it.
+#ifndef O_TMPFILE
+#define O_TMPFILE 0
+#endif
+
+int openat(int dirfd, const char *pathname, int flags, ...) {
+    if (dirfd == AT_FDCWD || pathname[0] == '/') {
+        return open(pathname, flags);
+    }
+
+    return __wasilibc_nocwd_openat_nomode(dirfd, pathname, flags);
+}
+
+int symlinkat(const char *target, int dirfd, const char *linkpath) {
+    if (dirfd == AT_FDCWD || linkpath[0] == '/') {
+        return symlink(target, linkpath);
+    }
+
+    return __wasilibc_nocwd_symlinkat(target, dirfd, linkpath);
+}
+
+ssize_t readlinkat(int dirfd, const char *__restrict pathname, char *__restrict buf, size_t bufsiz) {
+    if (dirfd == AT_FDCWD || pathname[0] == '/') {
+        return readlink(pathname, buf, bufsiz);
+    }
+
+    return __wasilibc_nocwd_readlinkat(dirfd, pathname, buf, bufsiz);
+}
+
+int mkdirat(int dirfd, const char *pathname, mode_t mode) {
+    if (dirfd == AT_FDCWD || pathname[0] == '/') {
+        return mkdir(pathname, mode);
+    }
+
+    return __wasilibc_nocwd_mkdirat_nomode(dirfd, pathname);
+}
+
+DIR *opendirat(int dirfd, const char *path) {
+    if (dirfd == AT_FDCWD || path[0] == '/') {
+        return opendir(path);
+    }
+
+    return __wasilibc_nocwd_opendirat(dirfd, path);
+}
+
+int scandirat(int dirfd, const char *dirp, struct dirent ***namelist,
+              int (*filter)(const struct dirent *),
+              int (*compar)(const struct dirent **, const struct dirent **)) {
+    if (dirfd == AT_FDCWD || dirp[0] == '/') {
+        return scandir(dirp, namelist, filter, compar);
+    }
+
+    return __wasilibc_nocwd_scandirat(dirfd, dirp, namelist, filter, compar);
+}
+
+int faccessat(int dirfd, const char *pathname, int mode, int flags) {
+    if (dirfd == AT_FDCWD || pathname[0] == '/') {
+        return __wasilibc_access(pathname, mode, flags);
+    }
+
+    return __wasilibc_nocwd_faccessat(dirfd, pathname, mode, flags);
+}
+
+int fstatat(int dirfd, const char *__restrict pathname, struct stat *__restrict statbuf, int flags) {
+    if (dirfd == AT_FDCWD || pathname[0] == '/') {
+        return __wasilibc_stat(pathname, statbuf, flags);
+    }
+
+    return __wasilibc_nocwd_fstatat(dirfd, pathname, statbuf, flags);
+}
+
+int utimensat(int dirfd, const char *pathname, const struct timespec times[2], int flags) {
+    if (dirfd == AT_FDCWD || pathname[0] == '/') {
+        return __wasilibc_utimens(pathname, times, flags);
+    }
+
+    return __wasilibc_nocwd_utimensat(dirfd, pathname, times, flags);
+}
+
+int linkat(int olddirfd, const char *oldpath, int newdirfd, const char *newpath, int flags) {
+    if ((olddirfd == AT_FDCWD || oldpath[0] == '/') &&
+        (newdirfd == AT_FDCWD || newpath[0] == '/')) {
+        return __wasilibc_link(oldpath, newpath, flags);
+    }
+    if (olddirfd == AT_FDCWD || oldpath[0] == '/') {
+        return __wasilibc_link_newat(oldpath, newdirfd, newpath, flags);
+    }
+    if (newdirfd == AT_FDCWD || newpath[0] == '/') {
+        return __wasilibc_link_oldat(olddirfd, oldpath, newpath, flags);
+    }
+
+    return __wasilibc_nocwd_linkat(olddirfd, oldpath, newdirfd, newpath, flags);
+}
+
+int renameat(int olddirfd, const char *oldpath, int newdirfd, const char *newpath) {
+    if ((olddirfd == AT_FDCWD || oldpath[0] == '/') &&
+        (newdirfd == AT_FDCWD || newpath[0] == '/')) {
+        return rename(oldpath, newpath);
+    }
+    if (olddirfd == AT_FDCWD || oldpath[0] == '/') {
+        return __wasilibc_rename_newat(oldpath, newdirfd, newpath);
+    }
+    if (newdirfd == AT_FDCWD || newpath[0] == '/') {
+        return __wasilibc_rename_oldat(olddirfd, oldpath, newpath);
+    }
+
+    return __wasilibc_nocwd_renameat(olddirfd, oldpath, newdirfd, newpath);
+}
+
+int __wasilibc_unlinkat(int dirfd, const char *path) {
+    if (dirfd == AT_FDCWD || path[0] == '/') {
+        return unlink(path);
+    }
+
+    return __wasilibc_nocwd___wasilibc_unlinkat(dirfd, path);
+}
+
+int __wasilibc_rmdirat(int dirfd, const char *path) {
+    if (dirfd == AT_FDCWD || path[0] == '/') {
+        return rmdir(path);
+    }
+
+    return __wasilibc_nocwd___wasilibc_rmdirat(dirfd, path);
+}