Migrate more fd-concerned functions from wutil into fds

Functions like wopen_cloexec have a new home in fds.cpp. This is in
preparation for reworking how internal fds avoid conflict with user fds.

src/fds.cpp

@@ -5,11 +5,17 @@
 #include "fds.h"
 
 #include <errno.h>
+#include <fcntl.h>
 #include <unistd.h>
 
+#include "common.h"
 #include "flog.h"
 #include "wutil.h"
 
+#if defined(__linux__)
+#include <sys/statfs.h>
+#endif
+
 void autoclose_fd_t::close() {
     if (fd_ < 0) return;
     exec_close(fd_);
@@ -63,6 +69,85 @@ maybe_t<autoclose_pipes_t> make_autoclose_pipes(const fd_set_t &fdset) {
     return autoclose_pipes_t(std::move(read_end), std::move(write_end));
 }
 
+int set_cloexec(int fd, bool should_set) {
+    // Note we don't want to overwrite existing flags like O_NONBLOCK which may be set. So fetch the
+    // existing flags and modify them.
+    int flags = fcntl(fd, F_GETFD, 0);
+    if (flags < 0) {
+        return -1;
+    }
+    int new_flags = flags;
+    if (should_set) {
+        new_flags |= FD_CLOEXEC;
+    } else {
+        new_flags &= ~FD_CLOEXEC;
+    }
+    if (flags == new_flags) {
+        return 0;
+    } else {
+        return fcntl(fd, F_SETFD, new_flags);
+    }
+}
+
+int open_cloexec(const std::string &path, int flags, mode_t mode) {
+    return open_cloexec(path.c_str(), flags, mode);
+}
+
+int open_cloexec(const char *path, int flags, mode_t mode) {
+    int fd;
+
+    // Prefer to use O_CLOEXEC.
+#ifdef O_CLOEXEC
+    fd = open(path, flags | O_CLOEXEC, mode);
+#else
+    fd = open(path, flags, mode);
+    if (fd >= 0 && !set_cloexec(fd)) {
+        exec_close(fd);
+        fd = -1;
+    }
+#endif
+    return fd;
+}
+
+int wopen_cloexec(const wcstring &pathname, int flags, mode_t mode) {
+    return open_cloexec(wcs2string(pathname), flags, mode);
+}
+
+int fd_check_is_remote(int fd) {
+    UNUSED(fd);
+#if defined(__linux__)
+    struct statfs buf {};
+    if (fstatfs(fd, &buf) < 0) {
+        return -1;
+    }
+    // Linux has constants for these like NFS_SUPER_MAGIC, SMB_SUPER_MAGIC, CIFS_MAGIC_NUMBER but
+    // these are in varying headers. Simply hard code them.
+    // NOTE: The cast is necessary for 32-bit systems because of the 4-byte CIFS_MAGIC_NUMBER
+    switch (static_cast<unsigned int>(buf.f_type)) {
+        case 0x6969:       // NFS_SUPER_MAGIC
+        case 0x517B:       // SMB_SUPER_MAGIC
+        case 0xFE534D42U:  // SMB2_MAGIC_NUMBER - not in the manpage
+        case 0xFF534D42U:  // CIFS_MAGIC_NUMBER
+            return 1;
+        default:
+            // Other FSes are assumed local.
+            return 0;
+    }
+#elif defined(ST_LOCAL)
+    // ST_LOCAL is a flag to statvfs, which is itself standardized.
+    // In practice the only system to use this path is NetBSD.
+    struct statvfs buf {};
+    if (fstatvfs(fd, &buf) < 0) return -1;
+    return (buf.f_flag & ST_LOCAL) ? 0 : 1;
+#elif defined(MNT_LOCAL)
+    struct statfs buf {};
+    if (fstatfs(fd, &buf) < 0) return -1;
+    return (buf.f_flags & MNT_LOCAL) ? 0 : 1;
+#else
+    return -1;
+#endif
+}
+
 void exec_close(int fd) {
     assert(fd >= 0 && "Invalid fd");
     while (close(fd) == -1) {

src/fds.h

@@ -4,10 +4,13 @@
 #define FISH_FDS_H
 
 #include <algorithm>
+#include <string>
 #include <vector>
 
 #include "maybe.h"
 
+using wcstring = std::wstring;
+
 /// Pipe redirection error message.
 #define PIPE_ERROR _(L"An error occurred while setting up pipe")
 
@@ -95,6 +98,27 @@ maybe_t<autoclose_pipes_t> make_autoclose_pipes(const fd_set_t &fdset);
 /// cloexec. \returns invalid fd on failure (in which case the given fd is still closed).
 autoclose_fd_t move_fd_to_unused(autoclose_fd_t fd, const fd_set_t &fdset);
 
+/// Sets CLO_EXEC on a given fd according to the value of \p should_set.
+int set_cloexec(int fd, bool should_set = true);
+
+/// Wide character version of open() that also sets the close-on-exec flag (atomically when
+/// possible).
+int wopen_cloexec(const wcstring &pathname, int flags, mode_t mode = 0);
+
+/// Narrow versions of wopen_cloexec.
+int open_cloexec(const std::string &path, int flags, mode_t mode = 0);
+int open_cloexec(const char *path, int flags, mode_t mode = 0);
+
+/// Mark an fd as nonblocking; returns errno or 0 on success.
+int make_fd_nonblocking(int fd);
+
+/// Mark an fd as blocking; returns errno or 0 on success.
+int make_fd_blocking(int fd);
+
+/// Check if an fd is on a remote filesystem (NFS, SMB, CFS)
+/// Return 1 if remote, 0 if local, -1 on error or if not implemented on this platform.
+int fd_check_is_remote(int fd);
+
 /// Close a file descriptor \p fd, retrying on EINTR.
 void exec_close(int fd);
 

src/fish_indent.cpp

@@ -39,6 +39,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 #include "env.h"
 #include "expand.h"
 #include "fish_version.h"
+#include "fds.h"
 #include "flog.h"
 #include "highlight.h"
 #include "operation_context.h"

src/history_file.cpp

@@ -2,10 +2,11 @@
 
 #include "history_file.h"
 
-#include <cstring>
-
+#include "fds.h"
 #include "history.h"
 
+#include <cstring>
+
 // Some forward declarations.
 static history_item_t decode_item_fish_2_0(const char *base, size_t len);
 static history_item_t decode_item_fish_1_x(const char *begin, size_t length);

src/iothread.cpp

@@ -19,6 +19,7 @@
 #include <thread>
 
 #include "common.h"
+#include "fds.h"
 #include "flog.h"
 #include "global_safety.h"
 #include "wutil.h"

src/wutil.cpp

@@ -12,9 +12,6 @@
 #include <sys/stat.h>
 
 #include <cstring>
-#if defined(__linux__)
-#include <sys/statfs.h>
-#endif
 #include <sys/mount.h>
 #include <sys/statvfs.h>
 #include <sys/types.h>
@@ -142,50 +139,6 @@ wcstring wgetcwd() {
     return wcstring();
 }
 
-int set_cloexec(int fd, bool should_set) {
-    // Note we don't want to overwrite existing flags like O_NONBLOCK which may be set. So fetch the
-    // existing flags and modify them.
-    int flags = fcntl(fd, F_GETFD, 0);
-    if (flags < 0) {
-        return -1;
-    }
-    int new_flags = flags;
-    if (should_set) {
-        new_flags |= FD_CLOEXEC;
-    } else {
-        new_flags &= ~FD_CLOEXEC;
-    }
-    if (flags == new_flags) {
-        return 0;
-    } else {
-        return fcntl(fd, F_SETFD, new_flags);
-    }
-}
-
-int open_cloexec(const std::string &path, int flags, mode_t mode) {
-    return open_cloexec(path.c_str(), flags, mode);
-}
-
-int open_cloexec(const char *path, int flags, mode_t mode) {
-    int fd;
-
-// Prefer to use O_CLOEXEC.
-#ifdef O_CLOEXEC
-    fd = open(path, flags | O_CLOEXEC, mode);
-#else
-    fd = open(path, flags, mode);
-    if (fd >= 0 && !set_cloexec(fd)) {
-        exec_close(fd);
-        fd = -1;
-    }
-#endif
-    return fd;
-}
-
-int wopen_cloexec(const wcstring &pathname, int flags, mode_t mode) {
-    cstring tmp = wcs2string(pathname);
-    return open_cloexec(tmp, flags, mode);
-}
 
 DIR *wopendir(const wcstring &name) {
     const cstring tmp = wcs2string(name);
@@ -256,40 +209,6 @@ int make_fd_blocking(int fd) {
     return err == -1 ? errno : 0;
 }
 
-int fd_check_is_remote(int fd) {
-#if defined(__linux__)
-    struct statfs buf {};
-    if (fstatfs(fd, &buf) < 0) {
-        return -1;
-    }
-    // Linux has constants for these like NFS_SUPER_MAGIC, SMB_SUPER_MAGIC, CIFS_MAGIC_NUMBER but
-    // these are in varying headers. Simply hard code them.
-    // NOTE: The cast is necessary for 32-bit systems because of the 4-byte CIFS_MAGIC_NUMBER
-    switch (static_cast<unsigned int>(buf.f_type)) {
-        case 0x6969:       // NFS_SUPER_MAGIC
-        case 0x517B:       // SMB_SUPER_MAGIC
-        case 0xFE534D42U:  // SMB2_MAGIC_NUMBER - not in the manpage
-        case 0xFF534D42U:  // CIFS_MAGIC_NUMBER
-            return 1;
-        default:
-            // Other FSes are assumed local.
-            return 0;
-    }
-#elif defined(ST_LOCAL)
-    // ST_LOCAL is a flag to statvfs, which is itself standardized.
-    // In practice the only system to use this path is NetBSD.
-    struct statvfs buf {};
-    if (fstatvfs(fd, &buf) < 0) return -1;
-    return (buf.f_flag & ST_LOCAL) ? 0 : 1;
-#elif defined(MNT_LOCAL)
-    struct statfs buf {};
-    if (fstatfs(fd, &buf) < 0) return -1;
-    return (buf.f_flags & MNT_LOCAL) ? 0 : 1;
-#else
-    return -1;
-#endif
-}
-
 static inline void safe_append(char *buffer, const char *s, size_t buffsize) {
     std::strncat(buffer, s, buffsize - std::strlen(buffer) - 1);
 }

src/wutil.h

@@ -19,27 +19,6 @@
 #include "common.h"
 #include "maybe.h"
 
-/// Sets CLO_EXEC on a given fd according to the value of \p should_set.
-int set_cloexec(int fd, bool should_set = true);
-
-/// Wide character version of open() that also sets the close-on-exec flag (atomically when
-/// possible).
-int wopen_cloexec(const wcstring &pathname, int flags, mode_t mode = 0);
-
-/// Narrow versions of wopen_cloexec.
-int open_cloexec(const std::string &path, int flags, mode_t mode = 0);
-int open_cloexec(const char *path, int flags, mode_t mode = 0);
-
-/// Mark an fd as nonblocking; returns errno or 0 on success.
-int make_fd_nonblocking(int fd);
-
-/// Mark an fd as blocking; returns errno or 0 on success.
-int make_fd_blocking(int fd);
-
-/// Check if an fd is on a remote filesystem (NFS, SMB, CFS)
-/// Return 1 if remote, 0 if local, -1 on error or if not implemented on this platform.
-int fd_check_is_remote(int fd);
-
 /// Wide character version of opendir(). Note that opendir() is guaranteed to set close-on-exec by
 /// POSIX (hooray).
 DIR *wopendir(const wcstring &name);