newlib: remove direct dependencies on VFS functions

poll: use "select" not "esp_vfs_select" move to newlib

pread, pwrite, select, utime: remove from newlib. VFS and/or LWIP will
provide aliases for these functions.

components/newlib/CMakeLists.txt

@@ -3,17 +3,13 @@ set(srcs
     "heap.c"
     "locks.c"
     "poll.c"
-    "pread.c"
-    "pwrite.c"
     "pthread.c"
     "random.c"
     "reent_init.c"
-    "select.c"
     "syscall_table.c"
     "syscalls.c"
     "termios.c"
-    "time.c"
+    "time.c")
-    "utime.c")
 set(include_dirs platform_include)
 
 if(CONFIG_SPIRAM_CACHE_WORKAROUND)

components/newlib/poll.c

@@ -1,4 +1,4 @@
-// Copyright 2019 Espressif Systems (Shanghai) PTE LTD
+// Copyright 2019-2020 Espressif Systems (Shanghai) PTE LTD
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -12,10 +12,84 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#include <stddef.h>
 #include <sys/poll.h>
-#include "esp_vfs.h"
+#include <sys/select.h>
+#include <sys/errno.h>
+#include <sys/param.h>
 
 int poll(struct pollfd *fds, nfds_t nfds, int timeout)
 {
-    return esp_vfs_poll(fds, nfds, timeout);
+    struct timeval tv = {
+        // timeout is in milliseconds
+        .tv_sec = timeout / 1000,
+        .tv_usec = (timeout % 1000) * 1000,
+    };
+    int max_fd = -1;
+    fd_set readfds;
+    fd_set writefds;
+    fd_set errorfds;
+    struct _reent* r = __getreent();
+    int ret = 0;
+
+    if (fds == NULL) {
+        __errno_r(r) = ENOENT;
+        return -1;
+    }
+
+    FD_ZERO(&readfds);
+    FD_ZERO(&writefds);
+    FD_ZERO(&errorfds);
+
+    for (int i = 0; i < nfds; ++i) {
+        fds[i].revents = 0;
+
+        if (fds[i].fd < 0) {
+            // revents should remain 0 and events ignored (according to the documentation of poll()).
+            continue;
+        }
+
+        if (fds[i].fd >= FD_SETSIZE) {
+            fds[i].revents |= POLLNVAL;
+            ++ret;
+            continue;
+        }
+
+        if (fds[i].events & (POLLIN | POLLRDNORM | POLLRDBAND | POLLPRI)) {
+            FD_SET(fds[i].fd, &readfds);
+            FD_SET(fds[i].fd, &errorfds);
+            max_fd = MAX(max_fd, fds[i].fd);
+        }
+
+        if (fds[i].events & (POLLOUT | POLLWRNORM | POLLWRBAND)) {
+            FD_SET(fds[i].fd, &writefds);
+            FD_SET(fds[i].fd, &errorfds);
+            max_fd = MAX(max_fd, fds[i].fd);
+        }
+    }
+
+    const int select_ret = select(max_fd + 1, &readfds, &writefds, &errorfds, timeout < 0 ? NULL: &tv);
+
+    if (select_ret > 0) {
+        ret += select_ret;
+
+        for (int i = 0; i < nfds; ++i) {
+            if (FD_ISSET(fds[i].fd, &readfds)) {
+                fds[i].revents |= POLLIN;
+            }
+
+            if (FD_ISSET(fds[i].fd, &writefds)) {
+                fds[i].revents |= POLLOUT;
+            }
+
+            if (FD_ISSET(fds[i].fd, &errorfds)) {
+                fds[i].revents |= POLLERR;
+            }
+        }
+    } else {
+        ret = select_ret;
+        // keeping the errno from select()
+    }
+
+    return ret;
 }

components/newlib/pread.c

@@ -1,21 +0,0 @@
-// Copyright 2019 Espressif Systems (Shanghai) PTE LTD
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include <unistd.h>
-#include "esp_vfs.h"
-
-ssize_t pread(int fd, void *dst, size_t size, off_t offset)
-{
-    return esp_vfs_pread(fd, dst, size, offset);
-}

components/newlib/pwrite.c

@@ -1,21 +0,0 @@
-// Copyright 2019 Espressif Systems (Shanghai) PTE LTD
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include <unistd.h>
-#include "esp_vfs.h"
-
-ssize_t pwrite(int fd, const void *src, size_t size, off_t offset)
-{
-    return esp_vfs_pwrite(fd, src, size, offset);
-}

components/newlib/select.c

@@ -1,64 +0,0 @@
-// Copyright 2018 Espressif Systems (Shanghai) PTE LTD
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include <sys/select.h>
-#include "esp_vfs.h"
-#include "sdkconfig.h"
-
-#ifdef CONFIG_LWIP_USE_ONLY_LWIP_SELECT
-#include "lwip/sockets.h"
-
-#ifdef CONFIG_VFS_SUPPRESS_SELECT_DEBUG_OUTPUT
-#define LOG_LOCAL_LEVEL ESP_LOG_NONE
-#endif //CONFIG_VFS_SUPPRESS_SELECT_DEBUG_OUTPUT
-#include "esp_log.h"
-
-static const char *TAG = "newlib_select";
-
-static void log_fd_set(const char *fds_name, const fd_set *fds)
-{
-    if (fds_name && fds) {
-        ESP_LOGD(TAG, "FDs in %s =", fds_name);
-        for (int i = 0; i < MAX_FDS; ++i) {
-            if (FD_ISSET(i, fds)) {
-                ESP_LOGD(TAG, "%d", i);
-            }
-        }
-    }
-}
-#endif //CONFIG_LWIP_USE_ONLY_LWIP_SELECT
-
-int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *errorfds, struct timeval *timeout)
-{
-#ifdef CONFIG_LWIP_USE_ONLY_LWIP_SELECT
-    ESP_LOGD(TAG, "lwip_select starts with nfds = %d", nfds);
-    if (timeout) {
-        ESP_LOGD(TAG, "timeout is %lds + %ldus", (long)timeout->tv_sec, timeout->tv_usec);
-    }
-    log_fd_set("readfds", readfds);
-    log_fd_set("writefds", writefds);
-    log_fd_set("errorfds", errorfds);
-
-    int ret = lwip_select(nfds, readfds, writefds, errorfds, timeout);
-
-    ESP_LOGD(TAG, "lwip_select returns %d", ret);
-    log_fd_set("readfds", readfds);
-    log_fd_set("writefds", writefds);
-    log_fd_set("errorfds", errorfds);
-
-    return ret;
-#else
-    return esp_vfs_select(nfds, readfds, writefds, errorfds, timeout);
-#endif
-}

components/newlib/utime.c

@@ -1,21 +0,0 @@
-// Copyright 2018 Espressif Systems (Shanghai) PTE LTD
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include <utime.h>
-#include "esp_vfs.h"
-
-int utime(const char *path, const struct utimbuf *times)
-{
-    return esp_vfs_utime(path, times);
-}