cloudlibc & libpreopen: changes for tagged unions

pchickey · pchickey · commit c2ae180deebe · 2020-02-24T11:36:05.000-08:00
we decided to abandon the upstream code guarded by
 #ifdef __wasilibc_unmodified_upstream // non-anonymous unions
because these changes are sprawling and those guards are of diminishing
importance
diff --git a/libc-bottom-half/cloudlibc/src/libc/poll/poll.c b/libc-bottom-half/cloudlibc/src/libc/poll/poll.c
@@ -21,27 +21,17 @@ int poll(struct pollfd *fds, size_t nfds, int timeout) {
       __wasi_subscription_t *subscription = &subscriptions[nevents++];
       *subscription = (__wasi_subscription_t){
           .userdata = (uintptr_t)pollfd,
-          .type = __WASI_EVENTTYPE_FD_READ,
-#ifdef __wasilibc_unmodified_upstream // non-anonymous unions
-          .fd_readwrite.fd = pollfd->fd,
-          .fd_readwrite.flags = __WASI_SUBSCRIPTION_FD_READWRITE_POLL,
-#else
-          .u.fd_readwrite.file_descriptor = pollfd->fd,
-#endif
+          .u.tag = __WASI_EVENTTYPE_FD_READ,
+          .u.u.fd_read.file_descriptor = pollfd->fd,
       };
       created_events = true;
     }
     if ((pollfd->events & POLLWRNORM) != 0) {
       __wasi_subscription_t *subscription = &subscriptions[nevents++];
       *subscription = (__wasi_subscription_t){
           .userdata = (uintptr_t)pollfd,
-          .type = __WASI_EVENTTYPE_FD_WRITE,
-#ifdef __wasilibc_unmodified_upstream // non-anonymous unions
-          .fd_readwrite.fd = pollfd->fd,
-          .fd_readwrite.flags = __WASI_SUBSCRIPTION_FD_READWRITE_POLL,
-#else
-          .u.fd_readwrite.file_descriptor = pollfd->fd,
-#endif
+          .u.tag = __WASI_EVENTTYPE_FD_WRITE,
+          .u.u.fd_write.file_descriptor = pollfd->fd,
       };
       created_events = true;
     }
@@ -59,14 +49,9 @@ int poll(struct pollfd *fds, size_t nfds, int timeout) {
   if (timeout >= 0) {
     __wasi_subscription_t *subscription = &subscriptions[nevents++];
     *subscription = (__wasi_subscription_t){
-        .type = __WASI_EVENTTYPE_CLOCK,
-#ifdef __wasilibc_unmodified_upstream // non-anonymous unions
-        .clock.clock_id = __WASI_CLOCK_REALTIME,
-        .clock.timeout = (__wasi_timestamp_t)timeout * 1000000,
-#else
-        .u.clock.id = __WASI_CLOCKID_REALTIME,
-        .u.clock.timeout = (__wasi_timestamp_t)timeout * 1000000,
-#endif
+        .u.tag = __WASI_EVENTTYPE_CLOCK,
+        .u.u.clock.id = __WASI_CLOCKID_REALTIME,
+        .u.u.clock.timeout = (__wasi_timestamp_t)timeout * 1000000,
     };
   }
 
@@ -92,8 +77,8 @@ int poll(struct pollfd *fds, size_t nfds, int timeout) {
   // Set revents fields.
   for (size_t i = 0; i < nevents; ++i) {
     const __wasi_event_t *event = &events[i];
-    if (event->type == __WASI_EVENTTYPE_FD_READ ||
-        event->type == __WASI_EVENTTYPE_FD_WRITE) {
+    if (event->u.tag == __WASI_EVENTTYPE_FD_READ ||
+        event->u.tag == __WASI_EVENTTYPE_FD_WRITE) {
       struct pollfd *pollfd = (struct pollfd *)(uintptr_t)event->userdata;
 #ifdef __wasilibc_unmodified_upstream // generated constant names
       if (event->error == __WASI_EBADF) {
@@ -114,14 +99,17 @@ int poll(struct pollfd *fds, size_t nfds, int timeout) {
         pollfd->revents |= POLLERR;
       } else {
         // Data can be read or written.
-        pollfd->revents |=
-            event->type == __WASI_EVENTTYPE_FD_READ ? POLLRDNORM : POLLWRNORM;
-#ifdef __wasilibc_unmodified_upstream // non-anonymous unions
-        if (event->fd_readwrite.flags & __WASI_EVENT_FD_READWRITE_HANGUP)
-#else
-        if (event->u.fd_readwrite.flags & __WASI_EVENTRWFLAGS_FD_READWRITE_HANGUP)
-#endif
-          pollfd->revents |= POLLHUP;
+        if (event->u.tag == __WASI_EVENTTYPE_FD_READ) {
+            pollfd->revents |= POLLRDNORM;
+            if (event->u.u.fd_read.flags & __WASI_EVENTRWFLAGS_FD_READWRITE_HANGUP) {
+              pollfd->revents |= POLLHUP;
+            }
+        } else if (event->u.tag == __WASI_EVENTTYPE_FD_WRITE) {
+            pollfd->revents |= POLLWRNORM;
+            if (event->u.u.fd_write.flags & __WASI_EVENTRWFLAGS_FD_READWRITE_HANGUP) {
+              pollfd->revents |= POLLHUP;
+            }
+        }
       }
     }
   }
diff --git a/libc-bottom-half/cloudlibc/src/libc/sys/ioctl/ioctl.c b/libc-bottom-half/cloudlibc/src/libc/sys/ioctl/ioctl.c
@@ -14,21 +14,12 @@ int ioctl(int fildes, int request, ...) {
       // Poll the file descriptor to determine how many bytes can be read.
       __wasi_subscription_t subscriptions[2] = {
           {
-              .type = __WASI_EVENTTYPE_FD_READ,
-#ifdef __wasilibc_unmodified_upstream // non-anonymous unions
-              .fd_readwrite.fd = fildes,
-              .fd_readwrite.flags = __WASI_SUBSCRIPTION_FD_READWRITE_POLL,
-#else
-              .u.fd_readwrite.file_descriptor = fildes,
-#endif
+              .u.tag = __WASI_EVENTTYPE_FD_READ,
+              .u.u.fd_read.file_descriptor = fildes,
           },
           {
-              .type = __WASI_EVENTTYPE_CLOCK,
-#ifdef __wasilibc_unmodified_upstream // non-anonymous unions
-              .clock.clock_id = __WASI_CLOCK_MONOTONIC,
-#else
-              .u.clock.id = __WASI_CLOCKID_MONOTONIC,
-#endif
+              .u.tag = __WASI_EVENTTYPE_CLOCK,
+              .u.u.clock.id = __WASI_CLOCKID_MONOTONIC,
           },
       };
       __wasi_event_t events[__arraycount(subscriptions)];
@@ -57,12 +48,8 @@ int ioctl(int fildes, int request, ...) {
           errno = event->error;
           return -1;
         }
-        if (event->type == __WASI_EVENTTYPE_FD_READ) {
-#ifdef __wasilibc_unmodified_upstream // non-anonymous unions
-          *result = event->fd_readwrite.nbytes;
-#else
-          *result = event->u.fd_readwrite.nbytes;
-#endif
+        if (event->u.tag == __WASI_EVENTTYPE_FD_READ) {
+          *result = event->u.u.fd_read.nbytes;
           return 0;
         }
       }
diff --git a/libc-bottom-half/cloudlibc/src/libc/sys/select/pselect.c b/libc-bottom-half/cloudlibc/src/libc/sys/select/pselect.c
@@ -49,13 +49,8 @@ int pselect(int nfds, fd_set *restrict readfds, fd_set *restrict writefds,
       __wasi_subscription_t *subscription = &subscriptions[nevents++];
       *subscription = (__wasi_subscription_t){
           .userdata = fd,
-          .type = __WASI_EVENTTYPE_FD_READ,
-#ifdef __wasilibc_unmodified_upstream // non-anonymous unions
-          .fd_readwrite.fd = fd,
-          .fd_readwrite.flags = __WASI_SUBSCRIPTION_FD_READWRITE_POLL,
-#else
-          .u.fd_readwrite.file_descriptor = fd,
-#endif
+          .u.tag = __WASI_EVENTTYPE_FD_READ,
+          .u.u.fd_read.file_descriptor = fd,
       };
     }
   }
@@ -67,13 +62,8 @@ int pselect(int nfds, fd_set *restrict readfds, fd_set *restrict writefds,
       __wasi_subscription_t *subscription = &subscriptions[nevents++];
       *subscription = (__wasi_subscription_t){
           .userdata = fd,
-          .type = __WASI_EVENTTYPE_FD_WRITE,
-#ifdef __wasilibc_unmodified_upstream // non-anonymous unions
-          .fd_readwrite.fd = fd,
-          .fd_readwrite.flags = __WASI_SUBSCRIPTION_FD_READWRITE_POLL,
-#else
-          .u.fd_readwrite.file_descriptor = fd,
-#endif
+          .u.tag = __WASI_EVENTTYPE_FD_WRITE,
+          .u.u.fd_write.file_descriptor = fd,
       };
     }
   }
@@ -82,18 +72,10 @@ int pselect(int nfds, fd_set *restrict readfds, fd_set *restrict writefds,
   if (timeout != NULL) {
     __wasi_subscription_t *subscription = &subscriptions[nevents++];
     *subscription = (__wasi_subscription_t){
-        .type = __WASI_EVENTTYPE_CLOCK,
-#ifdef __wasilibc_unmodified_upstream // non-anonymous unions
-        .clock.clock_id = __WASI_CLOCK_REALTIME,
-#else
-        .u.clock.id = __WASI_CLOCKID_REALTIME,
-#endif
+        .u.tag = __WASI_EVENTTYPE_CLOCK,
+        .u.u.clock.id = __WASI_CLOCKID_REALTIME,
     };
-#ifdef __wasilibc_unmodified_upstream // non-anonymous unions
-    if (!timespec_to_timestamp_clamp(timeout, &subscription->clock.timeout)) {
-#else
-    if (!timespec_to_timestamp_clamp(timeout, &subscription->u.clock.timeout)) {
-#endif
+    if (!timespec_to_timestamp_clamp(timeout, &subscription->u.u.clock.timeout)) {
       errno = EINVAL;
       return -1;
     }
@@ -115,8 +97,8 @@ int pselect(int nfds, fd_set *restrict readfds, fd_set *restrict writefds,
   // Test for EBADF.
   for (size_t i = 0; i < nevents; ++i) {
     const __wasi_event_t *event = &events[i];
-    if ((event->type == __WASI_EVENTTYPE_FD_READ ||
-         event->type == __WASI_EVENTTYPE_FD_WRITE) &&
+    if ((event->u.tag == __WASI_EVENTTYPE_FD_READ ||
+         event->u.tag == __WASI_EVENTTYPE_FD_WRITE) &&
 #ifdef __wasilibc_unmodified_upstream // generated constant names
         event->error == __WASI_EBADF) {
 #else
@@ -132,9 +114,9 @@ int pselect(int nfds, fd_set *restrict readfds, fd_set *restrict writefds,
   FD_ZERO(writefds);
   for (size_t i = 0; i < nevents; ++i) {
     const __wasi_event_t *event = &events[i];
-    if (event->type == __WASI_EVENTTYPE_FD_READ) {
+    if (event->u.tag == __WASI_EVENTTYPE_FD_READ) {
       readfds->__fds[readfds->__nfds++] = event->userdata;
-    } else if (event->type == __WASI_EVENTTYPE_FD_WRITE) {
+    } else if (event->u.tag == __WASI_EVENTTYPE_FD_WRITE) {
       writefds->__fds[writefds->__nfds++] = event->userdata;
     }
   }
diff --git a/libc-bottom-half/cloudlibc/src/libc/time/clock_nanosleep.c b/libc-bottom-half/cloudlibc/src/libc/time/clock_nanosleep.c
@@ -29,20 +29,11 @@ int clock_nanosleep(clockid_t clock_id, int flags, const struct timespec *rqtp,
 
   // Prepare polling subscription.
   __wasi_subscription_t sub = {
-      .type = __WASI_EVENTTYPE_CLOCK,
-#ifdef __wasilibc_unmodified_upstream // non-anonymous unions
-      .clock.clock_id = clock_id->id,
-      .clock.flags = flags,
-#else
-      .u.clock.id = clock_id->id,
-      .u.clock.flags = flags,
-#endif
+      .u.tag = __WASI_EVENTTYPE_CLOCK,
+      .u.u.clock.id = clock_id->id,
+      .u.u.clock.flags = flags,
   };
-#ifdef __wasilibc_unmodified_upstream // non-anonymous unions
-  if (!timespec_to_timestamp_clamp(rqtp, &sub.clock.timeout))
-#else
-  if (!timespec_to_timestamp_clamp(rqtp, &sub.u.clock.timeout))
-#endif
+  if (!timespec_to_timestamp_clamp(rqtp, &sub.u.u.clock.timeout))
     return EINVAL;
 
   // Block until polling event is triggered.
diff --git a/libc-bottom-half/libpreopen/libpreopen.c b/libc-bottom-half/libpreopen/libpreopen.c
@@ -538,7 +538,7 @@ __wasilibc_populate_libpreopen(void)
             break;
         if (ret != __WASI_ERRNO_SUCCESS)
             goto oserr;
-        switch (prestat.pr_type) {
+        switch (prestat.tag) {
         case __WASI_PREOPENTYPE_DIR: {
             char *path = malloc(prestat.u.dir.pr_name_len + 1);
             if (path == NULL)
