cygwin: implement support for cygwin and msys2

Cygwin and MSYS2 are POSIX layers implemented on top of Windows.
Use our POSIX `poll(2)` implementation of our poll abstraction.
For most other components we already have dedicated sources
implementing them in terms of APIs available on Cygwin or
providing non-implementations of components not supported.

This leaves only three components that need Cygwin-specific
implementations:

* uv_uptime: implement using sysinfo
* uv_resident_set_memory: add a placeholder returning UV_ENOSYS
* uv_cpu_info: add a placeholder returning UV_ENOSYS

Update our test suite to account for features not available
due to Cygwin platform limitations or our placeholders.

PR-URL: https://github.com/libuv/libuv/pull/1312
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>

Makefile.am

@@ -337,6 +337,19 @@ libuv_la_SOURCES += src/unix/android-ifaddrs.c \
                     src/unix/pthread-barrier.c
 endif
 
+if CYGWIN
+libuv_la_CFLAGS += -D_GNU_SOURCE
+libuv_la_SOURCES += src/unix/cygwin.c \
+                    src/unix/bsd-ifaddrs.c \
+                    src/unix/no-fsevents.c \
+                    src/unix/no-proctitle.c \
+                    src/unix/posix-hrtime.c \
+                    src/unix/posix-poll.c \
+                    src/unix/procfs-exepath.c \
+                    src/unix/sysinfo-loadavg.c \
+                    src/unix/sysinfo-memory.c
+endif
+
 if DARWIN
 include_HEADERS += include/uv-darwin.h \
                    include/pthread-barrier.h
@@ -384,6 +397,19 @@ libuv_la_SOURCES += src/unix/linux-core.c \
 test_run_tests_LDFLAGS += -lutil
 endif
 
+if MSYS
+libuv_la_CFLAGS += -D_GNU_SOURCE
+libuv_la_SOURCES += src/unix/cygwin.c \
+                    src/unix/bsd-ifaddrs.c \
+                    src/unix/no-fsevents.c \
+                    src/unix/no-proctitle.c \
+                    src/unix/posix-hrtime.c \
+                    src/unix/posix-poll.c \
+                    src/unix/procfs-exepath.c \
+                    src/unix/sysinfo-loadavg.c \
+                    src/unix/sysinfo-memory.c
+endif
+
 if NETBSD
 include_HEADERS += include/uv-bsd.h
 libuv_la_SOURCES += src/unix/bsd-ifaddrs.c \

configure.ac

@@ -52,10 +52,12 @@ AC_CHECK_LIB([socket], [socket])
 AC_SYS_LARGEFILE
 AM_CONDITIONAL([AIX],      [AS_CASE([$host_os],[aix*],          [true], [false])])
 AM_CONDITIONAL([ANDROID],  [AS_CASE([$host_os],[linux-android*],[true], [false])])
+AM_CONDITIONAL([CYGWIN],   [AS_CASE([$host_os],[cygwin*],       [true], [false])])
 AM_CONDITIONAL([DARWIN],   [AS_CASE([$host_os],[darwin*],       [true], [false])])
 AM_CONDITIONAL([DRAGONFLY],[AS_CASE([$host_os],[dragonfly*],    [true], [false])])
 AM_CONDITIONAL([FREEBSD],  [AS_CASE([$host_os],[*freebsd*],     [true], [false])])
 AM_CONDITIONAL([LINUX],    [AS_CASE([$host_os],[linux*],        [true], [false])])
+AM_CONDITIONAL([MSYS],     [AS_CASE([$host_os],[msys*],         [true], [false])])
 AM_CONDITIONAL([NETBSD],   [AS_CASE([$host_os],[netbsd*],       [true], [false])])
 AM_CONDITIONAL([OPENBSD],  [AS_CASE([$host_os],[openbsd*],      [true], [false])])
 AM_CONDITIONAL([OS390],    [AS_CASE([$host_os],[openedition*],  [true], [false])])

include/uv-unix.h

@@ -60,6 +60,8 @@
       defined(__OpenBSD__)         || \
       defined(__NetBSD__)
 # include "uv-bsd.h"
+#elif defined(__CYGWIN__) || defined(__MSYS__)
+# include "uv-posix.h"
 #endif
 
 #ifndef PTHREAD_BARRIER_SERIAL_THREAD

src/unix/bsd-ifaddrs.c

@@ -27,7 +27,9 @@
 
 #include <ifaddrs.h>
 #include <net/if.h>
+#if !defined(__CYGWIN__) && !defined(__MSYS__)
 #include <net/if_dl.h>
+#endif
 
 static int uv__ifaddr_exclude(struct ifaddrs *ent) {
   if (!((ent->ifa_flags & IFF_UP) && (ent->ifa_flags & IFF_RUNNING)))
@@ -107,9 +109,13 @@ int uv_interface_addresses(uv_interface_address_t** addresses, int* count) {
 
     for (i = 0; i < *count; i++) {
       if (strcmp(address->name, ent->ifa_name) == 0) {
+#if defined(__CYGWIN__) || defined(__MSYS__)
+        memset(address->phys_addr, 0, sizeof(address->phys_addr));
+#else
         struct sockaddr_dl* sa_addr;
         sa_addr = (struct sockaddr_dl*)(ent->ifa_addr);
         memcpy(address->phys_addr, LLADDR(sa_addr), sizeof(address->phys_addr));
+#endif
       }
       address++;
     }

src/unix/core.c

@@ -545,6 +545,7 @@ int uv__nonblock_ioctl(int fd, int set) {
 }
 
 
+#if !defined(__CYGWIN__) && !defined(__MSYS__)
 int uv__cloexec_ioctl(int fd, int set) {
   int r;
 
@@ -557,6 +558,7 @@ int uv__cloexec_ioctl(int fd, int set) {
 
   return 0;
 }
+#endif
 
 
 int uv__nonblock_fcntl(int fd, int set) {

src/unix/cygwin.c

@@ -0,0 +1,54 @@
+/* Copyright libuv project contributors. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "uv.h"
+#include "internal.h"
+
+#include <sys/sysinfo.h>
+#include <unistd.h>
+
+int uv_uptime(double* uptime) {
+  struct sysinfo info;
+
+  if (sysinfo(&info) < 0)
+    return -errno;
+
+  *uptime = info.uptime;
+  return 0;
+}
+
+int uv_resident_set_memory(size_t* rss) {
+  /* FIXME: read /proc/meminfo? */
+  *rss = 0;
+  return UV_ENOSYS;
+}
+
+int uv_cpu_info(uv_cpu_info_t** cpu_infos, int* count) {
+  /* FIXME: read /proc/stat? */
+  *cpu_infos = NULL;
+  *count = 0;
+  return UV_ENOSYS;
+}
+
+void uv_free_cpu_info(uv_cpu_info_t* cpu_infos, int count) {
+  (void)cpu_infos;
+  (void)count;
+}

test/task.h

@@ -209,7 +209,7 @@ UNUSED static int can_ipv6(void) {
   return supported;
 }
 
-#if defined(__MVS__)
+#if defined(__MVS__) || defined(__CYGWIN__) || defined(__MSYS__)
 # define NO_FS_EVENTS "Filesystem watching not supported on this platform."
 #endif
 

test/test-fs.c

@@ -125,7 +125,7 @@ static void check_permission(const char* filename, unsigned int mode) {
   ASSERT(req.result == 0);
 
   s = &req.statbuf;
-#ifdef _WIN32
+#if defined(_WIN32) || defined(__CYGWIN__) || defined(__MSYS__)
   /*
    * On Windows, chmod can only modify S_IWUSR (_S_IWRITE) bit,
    * so only testing for the specified flags.
@@ -240,7 +240,7 @@ static void chown_cb(uv_fs_t* req) {
 
 static void chown_root_cb(uv_fs_t* req) {
   ASSERT(req->fs_type == UV_FS_CHOWN);
-#ifdef _WIN32
+#if defined(_WIN32) || defined(__MSYS__)
   /* On windows, chown is a no-op and always succeeds. */
   ASSERT(req->result == 0);
 #else
@@ -250,7 +250,12 @@ static void chown_root_cb(uv_fs_t* req) {
   if (geteuid() == 0)
     ASSERT(req->result == 0);
   else
+#   if defined(__CYGWIN__)
+    /* On Cygwin, uid 0 is invalid (no root). */
+    ASSERT(req->result == UV_EINVAL);
+#   else
     ASSERT(req->result == UV_EPERM);
+#   endif
 #endif
   chown_cb_count++;
   uv_fs_req_cleanup(req);
@@ -641,6 +646,11 @@ TEST_IMPL(fs_file_loop) {
    */
   if (r == UV_ENOTSUP || r == UV_EPERM)
     return 0;
+#elif defined(__MSYS__)
+  /* MSYS2's approximation of symlinks with copies does not work for broken
+     links.  */
+  if (r == UV_ENOENT)
+    return 0;
 #endif
   ASSERT(r == 0);
   uv_fs_req_cleanup(&req);
@@ -1735,6 +1745,10 @@ TEST_IMPL(fs_symlink) {
   ASSERT(r == 0);
   uv_fs_req_cleanup(&req);
 
+#if defined(__MSYS__)
+  RETURN_SKIP("symlink reading is not supported on MSYS2");
+#endif
+
   r = uv_fs_readlink(NULL, &req, "test_file_symlink_symlink", NULL);
   ASSERT(r == 0);
   ASSERT(strcmp(req.ptr, "test_file_symlink") == 0);
@@ -1878,6 +1892,9 @@ TEST_IMPL(fs_symlink_dir) {
 
   r = uv_fs_lstat(NULL, &req, "test_dir_symlink", NULL);
   ASSERT(r == 0);
+#if defined(__MSYS__)
+  RETURN_SKIP("symlink reading is not supported on MSYS2");
+#endif
   ASSERT(((uv_stat_t*)req.ptr)->st_mode & S_IFLNK);
 #ifdef _WIN32
   ASSERT(((uv_stat_t*)req.ptr)->st_size == strlen(test_dir + 4));
@@ -2103,8 +2120,13 @@ TEST_IMPL(fs_futime) {
   uv_fs_req_cleanup(&req);
 
   r = uv_fs_futime(NULL, &req, file, atime, mtime, NULL);
+#if defined(__CYGWIN__) || defined(__MSYS__)
+  ASSERT(r == UV_ENOSYS);
+  RETURN_SKIP("futime not supported on Cygwin");
+#else
   ASSERT(r == 0);
   ASSERT(req.result == 0);
+#endif
   uv_fs_req_cleanup(&req);
 
   r = uv_fs_stat(NULL, &req, path, NULL);
@@ -2413,6 +2435,9 @@ TEST_IMPL(fs_rename_to_existing_file) {
 
 
 TEST_IMPL(fs_read_file_eof) {
+#if defined(__CYGWIN__) || defined(__MSYS__)
+  RETURN_SKIP("Cygwin pread at EOF may (incorrectly) return data!");
+#endif
   int r;
 
   /* Setup. */

test/test-ip6-addr.c

@@ -32,6 +32,10 @@
 
 
 TEST_IMPL(ip6_addr_link_local) {
+#if defined(__CYGWIN__) || defined(__MSYS__)
+  /* FIXME: Does Cygwin support this?  */
+  RETURN_SKIP("FIXME: This test needs more investigation on Cygwin");
+#endif
   char string_address[INET6_ADDRSTRLEN];
   uv_interface_address_t* addresses;
   uv_interface_address_t* address;

test/test-ping-pong.c

@@ -27,7 +27,11 @@
 
 static int completed_pingers = 0;
 
+#if defined(__CYGWIN__) || defined(__MSYS__)
+#define NUM_PINGS 100 /* fewer pings to avoid timeout */
+#else
 #define NUM_PINGS 1000
+#endif
 
 /* 64 bytes is enough for a pinger */
 #define BUFSIZE 10240

test/test-platform-output.c

@@ -47,8 +47,12 @@ TEST_IMPL(platform_output) {
   printf("uv_cwd: %s\n", buffer);
 
   err = uv_resident_set_memory(&rss);
+#if defined(__CYGWIN__) || defined(__MSYS__)
+  ASSERT(err == UV_ENOSYS);
+#else
   ASSERT(err == 0);
   printf("uv_resident_set_memory: %llu\n", (unsigned long long) rss);
+#endif
 
   err = uv_uptime(&uptime);
   ASSERT(err == 0);
@@ -73,6 +77,9 @@ TEST_IMPL(platform_output) {
          (unsigned long long) rusage.ru_maxrss);
 
   err = uv_cpu_info(&cpus, &count);
+#if defined(__CYGWIN__) || defined(__MSYS__)
+  ASSERT(err == UV_ENOSYS);
+#else
   ASSERT(err == 0);
 
   printf("uv_cpu_info:\n");
@@ -88,6 +95,7 @@ TEST_IMPL(platform_output) {
     printf("  times.nice: %llu\n",
            (unsigned long long) cpus[i].cpu_times.nice);
   }
+#endif
   uv_free_cpu_info(cpus, count);
 
   err = uv_interface_addresses(&interfaces, &count);

test/test-poll.c

@@ -595,7 +595,7 @@ TEST_IMPL(poll_unidirectional) {
 TEST_IMPL(poll_bad_fdtype) {
 #if !defined(__DragonFly__) && !defined(__FreeBSD__) && !defined(__sun) && \
     !defined(_AIX) && !defined(__MVS__) && !defined(__FreeBSD_kernel__) && \
-    !defined(__OpenBSD__)
+    !defined(__OpenBSD__) && !defined(__CYGWIN__) && !defined(__MSYS__)
   uv_poll_t poll_handle;
   int fd;
 

test/test-process-title.c

@@ -60,7 +60,7 @@ static void uv_get_process_title_edge_cases(void) {
 
 
 TEST_IMPL(process_title) {
-#if defined(__sun)
+#if defined(__sun) || defined(__CYGWIN__) || defined(__MSYS__)
   RETURN_SKIP("uv_(get|set)_process_title is not implemented.");
 #else
   /* Check for format string vulnerabilities. */

test/test-signal-multiple-loops.c

@@ -193,6 +193,13 @@ static void loop_creating_worker(void* context) {
 
 
 TEST_IMPL(signal_multiple_loops) {
+#if defined(__CYGWIN__) || defined(__MSYS__)
+  /* FIXME: This test needs more investigation.  Somehow the `read` in
+     uv__signal_lock fails spuriously with EACCES or even EAGAIN even
+     though it is supposed to be blocking.  Also the test hangs during
+     thread setup occasionally.  */
+  RETURN_SKIP("FIXME: This test needs more investigation on Cygwin");
+#endif
   uv_thread_t loop_creating_threads[NUM_LOOP_CREATING_THREADS];
   uv_thread_t signal_handling_threads[NUM_SIGNAL_HANDLING_THREADS];
   enum signal_action action;

test/test-spawn.c

@@ -1297,7 +1297,11 @@ TEST_IMPL(spawn_setuid_fails) {
   options.uid = 0;
 
   r = uv_spawn(uv_default_loop(), &process, &options);
+#if defined(__CYGWIN__)
+  ASSERT(r == UV_EINVAL);
+#else
   ASSERT(r == UV_EPERM);
+#endif
 
   r = uv_run(uv_default_loop(), UV_RUN_DEFAULT);
   ASSERT(r == 0);
@@ -1328,7 +1332,11 @@ TEST_IMPL(spawn_setgid_fails) {
   options.gid = 0;
 
   r = uv_spawn(uv_default_loop(), &process, &options);
+#if defined(__CYGWIN__)
+  ASSERT(r == UV_EINVAL);
+#else
   ASSERT(r == UV_EPERM);
+#endif
 
   r = uv_run(uv_default_loop(), UV_RUN_DEFAULT);
   ASSERT(r == 0);
@@ -1537,6 +1545,17 @@ TEST_IMPL(spawn_reads_child_path) {
   exepath[len] = 0;
   strcpy(path, "PATH=");
   strcpy(path + 5, exepath);
+#if defined(__CYGWIN__) || defined(__MSYS__)
+  /* Carry over the dynamic linker path in case the test runner
+     is linked against cyguv-1.dll or msys-uv-1.dll, see above.  */
+  {
+    char* syspath = getenv("PATH");
+    if (syspath != NULL) {
+      strcat(path, ":");
+      strcat(path, syspath);
+    }
+  }
+#endif
 
   env[0] = path;
   env[1] = getenv(dyld_path_var);

test/test-tcp-create-socket-early.c

@@ -164,7 +164,7 @@ TEST_IMPL(tcp_create_early_bad_bind) {
 #endif
 
   r = uv_tcp_bind(&client, (const struct sockaddr*) &addr, 0);
-#ifndef _WIN32
+#if !defined(_WIN32) && !defined(__CYGWIN__) && !defined(__MSYS__)
   ASSERT(r == UV_EINVAL);
 #else
   ASSERT(r == UV_EFAULT);

test/test-udp-create-socket-early.c

@@ -104,7 +104,7 @@ TEST_IMPL(udp_create_early_bad_bind) {
 #endif
 
   r = uv_udp_bind(&client, (const struct sockaddr*) &addr, 0);
-#ifndef _WIN32
+#if !defined(_WIN32) && !defined(__CYGWIN__) && !defined(__MSYS__)
   ASSERT(r == UV_EINVAL);
 #else
   ASSERT(r == UV_EFAULT);

test/test-udp-ipv6.c

@@ -163,6 +163,11 @@ static void do_test(uv_udp_recv_cb recv_cb, int bind_flags) {
 
 
 TEST_IMPL(udp_dual_stack) {
+#if defined(__CYGWIN__) || defined(__MSYS__)
+  /* FIXME: Does Cygwin support this?  */
+  RETURN_SKIP("FIXME: This test needs more investigation on Cygwin");
+#endif
+
   if (!can_ipv6())
     RETURN_SKIP("IPv6 not supported");
 

test/test-watcher-cross-stop.c

@@ -26,7 +26,12 @@
 #include <errno.h>
 
 /* NOTE: Number should be big enough to trigger this problem */
+#if defined(__CYGWIN__) || defined(__MSYS__)
+/* Cygwin crashes or hangs in socket() with too many AF_INET sockets.  */
+static uv_udp_t sockets[1250];
+#else
 static uv_udp_t sockets[2500];
+#endif
 static uv_udp_send_t reqs[ARRAY_SIZE(sockets)];
 static char slab[1];
 static unsigned int recv_cb_called;