Use fewer locks when accessing stdio

* src/alloc.c, src/bidi.c, src/emacs-module.c, src/pdumper.c:
* src/regex-emacs.c, src/unexhp9k800.c, src/unexmacosx.c:
* src/widget.c, src/xdisp.c, src/xselect.c, src/xterm.c:
Include sysstdio.h instead of stdio.h, to avoid locking
stdio streams in many cases.
* src/alloc.c (test_setjmp):
* src/bidi.c (bidi_dump_cached_states):
* src/cm.c (calccost):
* src/dispnew.c (init_display_interactive):
* src/emacs.c (main):
* src/image.c (convert_mono_to_color_image):
* src/minibuf.c (read_minibuf_noninteractive):
* src/nsfont.m (ns_descriptor_to_entity)
(ns_dump_glyphstring):
* src/nsterm.h (NSTRACE_MSG_NO_DASHES):
* src/nsterm.m (ns_mouse_position)
(sendEvent:, keyDown:, performDragOperation:):
* src/pdumper.c (dump_fingerprint, print_paths_to_root_1):
* src/print.c (debug_print):
* src/regex-emacs.c (debug_putchar, print_fastmap)
(print_partial_compiled_pattern, print_compiled_pattern)
(print_double_string, regex_compile):
* src/term.c (vfatal):
* src/unexhp9k800.c (read_header):
* src/unexmacosx.c (unexec_error):
* src/widget.c (EmacsFrameInitialize):
* src/xdisp.c (message_to_stderr, vmessage, dump_glyph_row)
(Fdump_glyph_matrix, Fdump_frame_glyph_matrix, dump_glyph_string):
* src/xfaces.c (Fdump_colors, Fdump_face):
* src/xselect.c (x_clipboard_manager_error_2):
* src/xterm.c (x_initialize):
* src/xwidget.c (WEBKIT_FN_INIT):
Prefer unlocked calls like fputs to locked calls like fprintf.
* src/charset.c (read_hex):
* src/cm.c (cmputc, cmcheckmagic):
* src/dispnew.c (update_frame, update_frame_with_menu)
(update_frame_1, Fsend_string_to_terminal, Fding)
(bitch_at_user):
* src/emacs.c (main, Fdump_emacs):
* src/emacs-module.c (module_abort):
* src/fileio.c (Fdo_auto_save):
* src/image.c (slurp_file)
(png_read_from_file, png_load_body, our_stdio_fill_input_buffer):
* src/keyboard.c (record_char, kbd_buffer_get_event)
(handle_interrupt):
* src/lread.c (readbyte_from_stdio, read1):
* src/minibuf.c (read_minibuf_noninteractive):
* src/print.c (printchar_to_stream, strout)
(Fredirect_debugging_output):
* src/sysdep.c (reset_sys_modes, close_output_streams)
(procfs_ttyname, procfs_get_total_memory):
* src/term.c (tty_ring_bell, tty_send_additional_strings)
(tty_set_terminal_modes, tty_reset_terminal_modes)
(tty_update_end, tty_clear_end_of_line, tty_write_glyphs)
(tty_write_glyphs_with_face, tty_insert_glyphs)
(tty_menu_activate):
* src/xfaces.c (Fx_load_color_file):
Simplify by using ordinary calls like putc to explicitly-unlocked
calls like putc_unlocked, since the ordinary calls are now
unlocked anyway.
* src/emacs.c (main, Fdump_emacs):
* src/pdumper.c (Fdump_emacs_portable):
Coalesce adjacent printfs.
* src/nsterm.h: Include sysstdio.h as this file’s macros rely on it.
* src/regex-emacs.c (print_compiled_pattern):
Omit redundant fflush.
* src/sysstdio.h: Include unlocked-io.h.
(clearerr_unlocked, feof_unlocked, ferror_unlocked)
(fflush_unlocked, fgets_unlocked, fputc_unlocked)
(fputs_unlocked, fread_unlocked, fwrite_unlocked)
(getc_unlocked, getchar_unlocked, putc_unlocked)
(putchar_unlocked): Remove these macros; now done by unlocked-io.h.
* src/xwidget.c: Include sysstdio.h.

29 files changed, 231 insertions, 282 deletions

diff --git a/src/alloc.c b/src/alloc.c
index 64aaa8acdfa..90817da5974 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -22,7 +22,6 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #include <errno.h>
 #include <stdint.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <limits.h>             /* For CHAR_BIT.  */
 #include <signal.h>             /* For SIGABRT, SIGDANGER.  */
@@ -38,6 +37,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include "ptr-bounds.h"
 #include "puresize.h"
 #include "sheap.h"
+#include "sysstdio.h"
 #include "systime.h"
 #include "character.h"
 #include "buffer.h"
@@ -4813,10 +4813,10 @@ test_setjmp (void)
          taking place, or the setjmp just didn't save the register.  */
 
       if (x == 1)
-        fprintf (stderr, SETJMP_WILL_LIKELY_WORK);
+        fputs (SETJMP_WILL_LIKELY_WORK, stderr);
       else
         {
-          fprintf (stderr, SETJMP_WILL_NOT_WORK);
+          fputs (SETJMP_WILL_NOT_WORK, stderr);
           exit (1);
         }
     }
diff --git a/src/bidi.c b/src/bidi.c
index c530d49c107..1430d223313 100644
--- a/src/bidi.c
+++ b/src/bidi.c
@@ -238,13 +238,13 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
    necessary.  */
 
 #include <config.h>
-#include <stdio.h>
 
 #include "lisp.h"
 #include "character.h"
 #include "buffer.h"
 #include "dispextern.h"
 #include "region-cache.h"
+#include "sysstdio.h"
 
 static bool bidi_initialized = 0;
 
@@ -3586,7 +3586,7 @@ bidi_dump_cached_states (void)
 
   if (bidi_cache_idx == 0)
     {
-      fprintf (stderr, "The cache is empty.\n");
+      fputs ("The cache is empty.\n", stderr);
       return;
     }
   fprintf (stderr, "Total of  %"pD"d state%s in cache:\n",
@@ -3597,13 +3597,11 @@ bidi_dump_cached_states (void)
   fputs ("ch  ", stderr);
   for (i = 0; i < bidi_cache_idx; i++)
     fprintf (stderr, "%*c", ndigits, bidi_cache[i].ch);
-  fputs ("\n", stderr);
-  fputs ("lvl ", stderr);
+  fputs ("\nlvl ", stderr);
   for (i = 0; i < bidi_cache_idx; i++)
     fprintf (stderr, "%*d", ndigits, bidi_cache[i].resolved_level);
-  fputs ("\n", stderr);
-  fputs ("pos ", stderr);
+  fputs ("\npos ", stderr);
   for (i = 0; i < bidi_cache_idx; i++)
     fprintf (stderr, "%*"pD"d", ndigits, bidi_cache[i].charpos);
-  fputs ("\n", stderr);
+  putc ('\n', stderr);
 }
diff --git a/src/charset.c b/src/charset.c
index c0700f972ee..85535e8bff1 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -415,23 +415,23 @@ load_charset_map (struct charset *charset, struct charset_map_entries *entries,
 static unsigned
 read_hex (FILE *fp, int lookahead, int *terminator, bool *overflow)
 {
-  int c = lookahead < 0 ? getc_unlocked (fp) : lookahead;
+  int c = lookahead < 0 ? getc (fp) : lookahead;
 
   while (true)
     {
       if (c == '#')
         do
-          c = getc_unlocked (fp);
+          c = getc (fp);
         while (0 <= c && c != '\n');
       else if (c == '0')
         {
-          c = getc_unlocked (fp);
+          c = getc (fp);
           if (c < 0 || c == 'x')
             break;
         }
       if (c < 0)
         break;
-      c = getc_unlocked (fp);
+      c = getc (fp);
     }
 
   unsigned n = 0;
@@ -440,7 +440,7 @@ read_hex (FILE *fp, int lookahead, int *terminator, bool *overflow)
   if (0 <= c)
     while (true)
       {
-        c = getc_unlocked (fp);
+        c = getc (fp);
         int digit = char_hexdigit (c);
         if (digit < 0)
           break;
diff --git a/src/cm.c b/src/cm.c
index 71cc94759fb..e09216a854b 100644
--- a/src/cm.c
+++ b/src/cm.c
@@ -45,8 +45,8 @@ int
 cmputc (int c)
 {
   if (current_tty->termscript)
-    putc_unlocked (c & 0177, current_tty->termscript);
-  putc_unlocked (c & 0177, current_tty->output);
+    putc (c & 0177, current_tty->termscript);
+  putc (c & 0177, current_tty->output);
   return c;
 }
 
@@ -117,11 +117,11 @@ cmcheckmagic (struct tty_display_info *tty)
       if (!MagicWrap (tty) || curY (tty) >= FrameRows (tty) - 1)
         emacs_abort ();
       if (tty->termscript)
-        putc_unlocked ('\r', tty->termscript);
-      putc_unlocked ('\r', tty->output);
+        putc ('\r', tty->termscript);
+      putc ('\r', tty->output);
       if (tty->termscript)
-        putc_unlocked ('\n', tty->termscript);
-      putc_unlocked ('\n', tty->output);
+        putc ('\n', tty->termscript);
+      putc ('\n', tty->output);
       curX (tty) = 0;
       curY (tty)++;
     }
@@ -205,7 +205,7 @@ calccost (struct tty_display_info *tty,
         p = tty->Wcm->cm_down, c = tty->Wcm->cc_down;
     if (c == BIG) {             /* caint get thar from here */
         if (doit)
-            printf ("OOPS");
+          fputs ("OOPS", stdout);
         return c;
     }
     totalcost = c * deltay;
@@ -288,7 +288,7 @@ dodelta:
     if (c == BIG) {             /* caint get thar from here */
 fail:
         if (doit)
-            printf ("OOPS");
+          fputs ("OOPS", stdout);
         return BIG;
     }
     totalcost += c * deltax;
diff --git a/src/dispnew.c b/src/dispnew.c
index 956f3ea3573..0131b63767b 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -3126,9 +3126,9 @@ update_frame (struct frame *f, bool force_p, bool inhibit_hairy_id_p)
       if (FRAME_TERMCAP_P (f) || FRAME_MSDOS_P (f))
         {
           if (FRAME_TTY (f)->termscript)
-            fflush_unlocked (FRAME_TTY (f)->termscript);
+            fflush (FRAME_TTY (f)->termscript);
           if (FRAME_TERMCAP_P (f))
-            fflush_unlocked (FRAME_TTY (f)->output);
+            fflush (FRAME_TTY (f)->output);
         }
 
       /* Check window matrices for lost pointers.  */
@@ -3181,8 +3181,8 @@ update_frame_with_menu (struct frame *f, int row, int col)
   update_end (f);
 
   if (FRAME_TTY (f)->termscript)
-    fflush_unlocked (FRAME_TTY (f)->termscript);
-  fflush_unlocked (FRAME_TTY (f)->output);
+    fflush (FRAME_TTY (f)->termscript);
+  fflush (FRAME_TTY (f)->output);
   /* Check window matrices for lost pointers.  */
 #if GLYPH_DEBUG
 #if 0
@@ -4621,7 +4621,7 @@ update_frame_1 (struct frame *f, bool force_p, bool inhibit_id_p,
                   ptrdiff_t outq = __fpending (display_output);
                   if (outq > 900
                       || (outq > 20 && ((i - 1) % preempt_count == 0)))
-                    fflush_unlocked (display_output);
+                    fflush (display_output);
                 }
             }
 
@@ -5745,13 +5745,13 @@ when TERMINAL is nil.  */)
 
       if (tty->termscript)
         {
-          fwrite_unlocked (SDATA (string), 1, SBYTES (string), tty->termscript);
-          fflush_unlocked (tty->termscript);
+          fwrite (SDATA (string), 1, SBYTES (string), tty->termscript);
+          fflush (tty->termscript);
         }
       out = tty->output;
     }
-  fwrite_unlocked (SDATA (string), 1, SBYTES (string), out);
-  fflush_unlocked (out);
+  fwrite (SDATA (string), 1, SBYTES (string), out);
+  fflush (out);
   unblock_input ();
   return Qnil;
 }
@@ -5766,7 +5766,7 @@ terminate any keyboard macro currently executing.  */)
   if (!NILP (arg))
     {
       if (noninteractive)
-        putchar_unlocked (07);
+        putchar (07);
       else
         ring_bell (XFRAME (selected_frame));
     }
@@ -5780,7 +5780,7 @@ void
 bitch_at_user (void)
 {
   if (noninteractive)
-    putchar_unlocked (07);
+    putchar (07);
   else if (!INTERACTIVE)  /* Stop executing a keyboard macro.  */
     {
       const char *msg
@@ -6205,12 +6205,14 @@ init_display_interactive (void)
 #endif
   if (!terminal_type)
     {
+      char const *msg
+        = "Please set the environment variable TERM; see 'tset'.\n";
 #ifdef HAVE_WINDOW_SYSTEM
       if (! inhibit_window_system)
-        fprintf (stderr, "Please set the environment variable DISPLAY or TERM (see 'tset').\n");
-      else
+        msg = ("Please set the environment variable DISPLAY or TERM; "
+               "see 'tset'.\n");
 #endif /* HAVE_WINDOW_SYSTEM */
-        fprintf (stderr, "Please set the environment variable TERM; see 'tset'.\n");
+      fputs (msg, stderr);
       exit (1);
     }
 
diff --git a/src/emacs-module.c b/src/emacs-module.c
index c856663d2ff..8c09ea6bb6c 100644
--- a/src/emacs-module.c
+++ b/src/emacs-module.c
@@ -81,7 +81,6 @@ To add a new module function, proceed as follows:
 #include <stdarg.h>
 #include <stddef.h>
 #include <stdint.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
 
@@ -91,6 +90,7 @@ To add a new module function, proceed as follows:
 #include "coding.h"
 #include "keyboard.h"
 #include "syssignal.h"
+#include "sysstdio.h"
 #include "thread.h"
 
 #include <intprops.h>
@@ -1304,7 +1304,7 @@ module_abort (const char *format, ...)
   va_start (args, format);
   vfprintf (stderr, format, args);
   va_end (args);
-  fputc ('\n', stderr);
+  putc ('\n', stderr);
   fflush (NULL);
   emacs_abort ();
 }
diff --git a/src/emacs.c b/src/emacs.c
index 0f03dd656d3..9c93748a0f5 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -1125,12 +1125,12 @@ main (int argc, char **argv)
           tem2 = Fsymbol_value (intern_c_string ("emacs-copyright"));
           if (!STRINGP (tem))
             {
-              fprintf (stderr, "Invalid value of 'emacs-version'\n");
+              fputs ("Invalid value of 'emacs-version'\n", stderr);
               exit (1);
             }
           if (!STRINGP (tem2))
             {
-              fprintf (stderr, "Invalid value of 'emacs-copyright'\n");
+              fputs ("Invalid value of 'emacs-copyright'\n", stderr);
               exit (1);
             }
           else
@@ -1144,13 +1144,14 @@ main (int argc, char **argv)
           version = emacs_version;
           copyright = emacs_copyright;
         }
-      printf ("%s %s\n", PACKAGE_NAME, version);
-      printf ("%s\n", copyright);
-      printf ("%s comes with ABSOLUTELY NO WARRANTY.\n", PACKAGE_NAME);
-      printf ("You may redistribute copies of %s\n", PACKAGE_NAME);
-      printf ("under the terms of the GNU General Public License.\n");
-      printf ("For more information about these matters, ");
-      printf ("see the file named COPYING.\n");
+      printf (("%s %s\n"
+               "%s\n"
+               "%s comes with ABSOLUTELY NO WARRANTY.\n"
+               "You may redistribute copies of %s\n"
+               "under the terms of the GNU General Public License.\n"
+               "For more information about these matters, "
+               "see the file named COPYING.\n"),
+              PACKAGE_NAME, version, copyright, PACKAGE_NAME, PACKAGE_NAME);
       exit (0);
     }
 
@@ -1246,7 +1247,7 @@ main (int argc, char **argv)
     }
 #endif /* HAVE_SETRLIMIT and RLIMIT_STACK and not CYGWIN */
 
-  clearerr_unlocked (stdin);
+  clearerr (stdin);
 
   emacs_backtrace (-1);
 
@@ -1344,7 +1345,7 @@ main (int argc, char **argv)
       int i;
       printf ("Usage: %s [OPTION-OR-FILENAME]...\n", argv[0]);
       for (i = 0; i < ARRAYELTS (usage_message); i++)
-        fputs_unlocked (usage_message[i], stdout);
+        fputs (usage_message[i], stdout);
       exit (0);
     }
 
@@ -1402,7 +1403,7 @@ main (int argc, char **argv)
              before exiting.  */
           if (emacs_pipe (daemon_pipe) != 0)
             {
-              fprintf (stderr, "Cannot pipe!\n");
+              fputs ("Cannot pipe!\n", stderr);
               exit (1);
             }
         } /* daemon_type == 2 */
@@ -1412,10 +1413,10 @@ main (int argc, char **argv)
       int systemd_socket = sd_listen_fds (1);
 
       if (systemd_socket > 1)
-        fprintf (stderr,
-                 ("\n"
-                  "Warning: systemd passed more than one socket to Emacs.\n"
-                  "Try 'Accept=false' in the Emacs socket unit file.\n"));
+        fputs (("\n"
+                "Warning: systemd passed more than one socket to Emacs.\n"
+                "Try 'Accept=false' in the Emacs socket unit file.\n"),
+               stderr);
       else if (systemd_socket == 1
                && (0 < sd_is_socket (SD_LISTEN_FDS_START,
                                      AF_UNSPEC, SOCK_STREAM, 1)))
@@ -1423,9 +1424,10 @@ main (int argc, char **argv)
 #endif /* HAVE_LIBSYSTEMD */
 
 #ifdef USE_GTK
-      fprintf (stderr, "\nWarning: due to a long standing Gtk+ bug\nhttps://gitlab.gnome.org/GNOME/gtk/issues/221\n\
+      fputs ("\nWarning: due to a long standing Gtk+ bug\nhttps://gitlab.gnome.org/GNOME/gtk/issues/221\n\
 Emacs might crash when run in daemon mode and the X11 connection is unexpectedly lost.\n\
-Using an Emacs configured with --with-x-toolkit=lucid does not have this problem.\n");
+Using an Emacs configured with --with-x-toolkit=lucid does not have this problem.\n",
+             stderr);
 #endif /* USE_GTK */
 
       if (daemon_type == 2)
@@ -1457,12 +1459,12 @@ Using an Emacs configured with --with-x-toolkit=lucid does not have this problem
 
               if (retval < 0)
                 {
-                  fprintf (stderr, "Error reading status from child\n");
+                  fputs ("Error reading status from child\n", stderr);
                   exit (1);
                 }
               else if (retval == 0)
                 {
-                  fprintf (stderr, "Error: server did not start correctly\n");
+                  fputs ("Error: server did not start correctly\n", stderr);
                   exit (1);
                 }
 
@@ -1488,7 +1490,7 @@ Using an Emacs configured with --with-x-toolkit=lucid does not have this problem
 
                 if (! (0 <= fdStrlen && fdStrlen < sizeof fdStr))
                   {
-                    fprintf (stderr, "daemon: child name too long\n");
+                    fputs ("daemon: child name too long\n", stderr);
                     exit (EXIT_CANNOT_INVOKE);
                   }
 
@@ -1504,10 +1506,11 @@ Using an Emacs configured with --with-x-toolkit=lucid does not have this problem
             /* In exec'd: parse special dname into pipe and name info. */
             if (!dname_arg || !*dname_arg || strnlen (dname_arg, 71) == 71
                 || !strchr (dname_arg, '\n'))
-          {
-            fprintf (stderr, "emacs daemon: daemon name absent or too long\n");
-            exit (EXIT_CANNOT_INVOKE);
-          }
+              {
+                fputs ("emacs daemon: daemon name absent or too long\n",
+                       stderr);
+                exit (EXIT_CANNOT_INVOKE);
+              }
             dname_arg2[0] = '\0';
             sscanf (dname_arg, "\n%d,%d\n%s", &(daemon_pipe[0]), &(daemon_pipe[1]),
                     dname_arg2);
@@ -1531,7 +1534,7 @@ Using an Emacs configured with --with-x-toolkit=lucid does not have this problem
           exit (1);
         }
 #else /* MSDOS */
-      fprintf (stderr, "This platform does not support daemon mode.\n");
+      fputs ("This platform does not support daemon mode.\n", stderr);
       exit (1);
 #endif /* MSDOS */
       if (dname_arg)
@@ -2545,16 +2548,15 @@ You must run Emacs in batch mode in order to dump it.  */)
 #  define MAX_HEAP_BSS_DIFF (1024 * 1024)
 
   if (heap_bss_diff > MAX_HEAP_BSS_DIFF)
-    {
-      fprintf (stderr, "**************************************************\n");
-      fprintf (stderr, "Warning: Your system has a gap between BSS and the\n");
-      fprintf (stderr, ("heap (%"PRIuMAX" bytes).  "
-                        "This usually means that exec-shield\n"),
-               heap_bss_diff);
-      fprintf (stderr, "or something similar is in effect.  The dump may\n");
-      fprintf (stderr, "fail because of this.  See the section about\n");
-      fprintf (stderr, "exec-shield in etc/PROBLEMS for more information.\n");
-      fprintf (stderr, "**************************************************\n");
+    fprintf (stderr,
+             ("**************************************************\n"
+              "Warning: Your system has a gap between BSS and the\n"
+              "heap (%"PRIuMAX" bytes). This usually means that exec-shield\n"
+              "or something similar is in effect.  The dump may\n"
+              "fail because of this.  See the section about\n"
+              "exec-shield in etc/PROBLEMS for more information.\n"
+              "**************************************************\n"),
+             heap_bss_diff);
     }
 # endif
 
@@ -2591,7 +2593,7 @@ You must run Emacs in batch mode in order to dump it.  */)
   }
 # endif
 
-  fflush_unlocked (stdout);
+  fflush (stdout);
   /* Tell malloc where start of impure now is.  */
   /* Also arrange for warnings when nearly out of space.  */
 # if !defined SYSTEM_MALLOC && !defined HYBRID_MALLOC && !defined WINDOWSNT
diff --git a/src/fileio.c b/src/fileio.c
index 8f23a305a52..cce49c43b2e 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -5787,12 +5787,12 @@ A non-nil CURRENT-ONLY argument means save only current buffer.  */)
           {
             block_input ();
             if (!NILP (BVAR (b, filename)))
-              fwrite_unlocked (SDATA (BVAR (b, filename)), 1,
-                               SBYTES (BVAR (b, filename)), stream);
-            putc_unlocked ('\n', stream);
-            fwrite_unlocked (SDATA (BVAR (b, auto_save_file_name)), 1,
-                             SBYTES (BVAR (b, auto_save_file_name)), stream);
-            putc_unlocked ('\n', stream);
+              fwrite (SDATA (BVAR (b, filename)), 1,
+                      SBYTES (BVAR (b, filename)), stream);
+            putc ('\n', stream);
+            fwrite (SDATA (BVAR (b, auto_save_file_name)), 1,
+                    SBYTES (BVAR (b, auto_save_file_name)), stream);
+            putc ('\n', stream);
             unblock_input ();
           }
 
@@ -5987,7 +5987,7 @@ effect except for flushing STREAM's data.  */)
 
   binmode = NILP (mode) ? O_TEXT : O_BINARY;
   if (fp != stdin)
-    fflush_unlocked (fp);
+    fflush (fp);
 
   return (set_binary_mode (fileno (fp), binmode) == O_BINARY) ? Qt : Qnil;
 }
diff --git a/src/image.c b/src/image.c
index b4b6c1bac1c..e898a7364a8 100644
--- a/src/image.c
+++ b/src/image.c
@@ -2991,7 +2991,7 @@ slurp_file (int fd, ptrdiff_t *size)
              This can happen if the file grows as we read it.  */
           ptrdiff_t buflen = st.st_size;
           buf = xmalloc (buflen + 1);
-          if (fread_unlocked (buf, 1, buflen + 1, fp) == buflen)
+          if (fread (buf, 1, buflen + 1, fp) == buflen)
             *size = buflen;
           else
             {
@@ -3338,7 +3338,7 @@ convert_mono_to_color_image (struct frame *f, struct image *img,
   DeleteDC (new_img_dc);
   DeleteObject (img->pixmap);
   if (new_pixmap == 0)
-    fprintf (stderr, "Failed to convert image to color.\n");
+    fputs ("Failed to convert image to color.\n", stderr);
   else
     img->pixmap = new_pixmap;
 }
@@ -6427,7 +6427,7 @@ png_read_from_file (png_structp png_ptr, png_bytep data, png_size_t length)
 {
   FILE *fp = png_get_io_ptr (png_ptr);
 
-  if (fread_unlocked (data, 1, length, fp) < length)
+  if (fread (data, 1, length, fp) < length)
     png_error (png_ptr, "Read error");
 }
 
@@ -6490,7 +6490,7 @@ png_load_body (struct frame *f, struct image *img, struct png_load_context *c)
         }
 
       /* Check PNG signature.  */
-      if (fread_unlocked (sig, 1, sizeof sig, fp) != sizeof sig
+      if (fread (sig, 1, sizeof sig, fp) != sizeof sig
           || png_sig_cmp (sig, 0, sizeof sig))
         {
           fclose (fp);
@@ -7100,8 +7100,7 @@ our_stdio_fill_input_buffer (j_decompress_ptr cinfo)
     {
       ptrdiff_t bytes;
 
-      bytes = fread_unlocked (src->buffer, 1, JPEG_STDIO_BUFFER_SIZE,
-                              src->file);
+      bytes = fread (src->buffer, 1, JPEG_STDIO_BUFFER_SIZE, src->file);
       if (bytes > 0)
         src->mgr.bytes_in_buffer = bytes;
       else
diff --git a/src/keyboard.c b/src/keyboard.c
index 56916e0cb4e..c47eecab9fb 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -3311,7 +3311,7 @@ record_char (Lisp_Object c)
       if (FIXNUMP (c))
         {
           if (XUFIXNUM (c) < 0x100)
-            putc_unlocked (XUFIXNUM (c), dribble);
+            putc (XUFIXNUM (c), dribble);
           else
             fprintf (dribble, " 0x%"pI"x", XUFIXNUM (c));
         }
@@ -3324,15 +3324,14 @@ record_char (Lisp_Object c)
 
           if (SYMBOLP (dribblee))
             {
-              putc_unlocked ('<', dribble);
-              fwrite_unlocked (SDATA (SYMBOL_NAME (dribblee)), sizeof (char),
-                               SBYTES (SYMBOL_NAME (dribblee)),
-                               dribble);
-              putc_unlocked ('>', dribble);
+              putc ('<', dribble);
+              fwrite (SDATA (SYMBOL_NAME (dribblee)), sizeof (char),
+                      SBYTES (SYMBOL_NAME (dribblee)), dribble);
+              putc ('>', dribble);
             }
         }
 
-      fflush_unlocked (dribble);
+      fflush (dribble);
       unblock_input ();
     }
 }
@@ -3769,7 +3768,7 @@ kbd_buffer_get_event (KBOARD **kbp,
          detaching from the terminal.  */
       || (IS_DAEMON && DAEMON_RUNNING))
     {
-      int c = getchar_unlocked ();
+      int c = getchar ();
       XSETINT (obj, c);
       *kbp = current_kboard;
       return obj;
@@ -10394,7 +10393,7 @@ handle_interrupt (bool in_signal_handler)
           sigemptyset (&blocked);
           sigaddset (&blocked, SIGINT);
           pthread_sigmask (SIG_BLOCK, &blocked, 0);
-          fflush_unlocked (stdout);
+          fflush (stdout);
         }
 
       reset_all_sys_modes ();
diff --git a/src/lread.c b/src/lread.c
index 27529c3d630..e06eafcf6cf 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -490,13 +490,12 @@ readbyte_from_stdio (void)
   block_input ();
 
   /* Interrupted reads have been observed while reading over the network.  */
-  while ((c = getc_unlocked (instream)) == EOF && errno == EINTR
-         && ferror_unlocked (instream))
+  while ((c = getc (instream)) == EOF && errno == EINTR && ferror (instream))
     {
       unblock_input ();
       maybe_quit ();
       block_input ();
-      clearerr_unlocked (instream);
+      clearerr (instream);
     }
 
   unblock_input ();
@@ -3063,7 +3062,7 @@ read1 (Lisp_Object readcharfun, int *pch, bool first_in_list)
                   = c = infile->buf[--infile->lookahead];
               block_input ();
               for (; i < nskip && 0 <= c; i++)
-                saved_doc_string[i] = c = getc_unlocked (instream);
+                saved_doc_string[i] = c = getc (instream);
               unblock_input ();
 
               saved_doc_string_length = i;
diff --git a/src/minibuf.c b/src/minibuf.c
index d932dbe8e20..d9a6e15b05d 100644
--- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -206,15 +206,15 @@ read_minibuf_noninteractive (Lisp_Object prompt, bool expflag,
       suppress_echo_on_tty (STDIN_FILENO);
     }
 
-  fwrite_unlocked (SDATA (prompt), 1, SBYTES (prompt), stdout);
-  fflush_unlocked (stdout);
+  fwrite (SDATA (prompt), 1, SBYTES (prompt), stdout);
+  fflush (stdout);
 
   val = Qnil;
   size = 100;
   len = 0;
   line = xmalloc (size);
 
-  while ((c = getchar_unlocked ()) != '\n' && c != '\r')
+  while ((c = getchar ()) != '\n' && c != '\r')
     {
       if (c == EOF)
         {
@@ -224,7 +224,7 @@ read_minibuf_noninteractive (Lisp_Object prompt, bool expflag,
       else
         {
           if (hide_char)
-            fprintf (stdout, "%c", hide_char);
+            putchar (hide_char);
           if (len == size)
             line = xpalloc (line, &size, 1, -1, sizeof *line);
           line[len++] = c;
@@ -234,7 +234,7 @@ read_minibuf_noninteractive (Lisp_Object prompt, bool expflag,
   /* Reset tty.  */
   if (hide_char)
     {
-      fprintf (stdout, "\n");
+      putc ('\n', stdout);
       if (etty_valid)
         {
           emacs_set_tty (STDIN_FILENO, &etty, 0);
diff --git a/src/nsfont.m b/src/nsfont.m
index eca97ab86cc..e22a954e63f 100644
--- a/src/nsfont.m
+++ b/src/nsfont.m
@@ -212,7 +212,7 @@ ns_descriptor_to_entity (NSFontDescriptor *desc,
 
     if (NSFONT_TRACE)
       {
-        fprintf (stderr, "created font_entity:\n    ");
+        fputs ("created font_entity:\n    ", stderr);
         debug_print (font_entity);
       }
 
@@ -1472,16 +1472,13 @@ ns_dump_glyphstring (struct glyph_string *s)
 {
   int i;
 
-  fprintf (stderr, "Glyph string len = %d at (%d, %d) overhang (%d, %d),"
-"overlap = %d, bg_filled = %d:",
+  fprintf (stderr, ("Glyph string len = %d at (%d, %d) overhang (%d, %d),"
+                    "overlap = %d, bg_filled = %d:"),
            s->nchars, s->x, s->y, s->left_overhang, s->right_overhang,
            s->row->overlapping_p, s->background_filled_p);
   for (i =0; i<s->nchars; i++)
-    {
-      int c = s->first_glyph[i].u.ch;
-      fprintf (stderr, "%c", c);
-    }
-  fprintf (stderr, "\n");
+    putc (s->first_glyph[i].u.ch, stderr);
+  putc ('\n', stderr);
 }
 
 static void syms_of_nsfont_for_pdumper (void);
diff --git a/src/nsterm.h b/src/nsterm.h
index 567f462ec69..9773eb3e662 100644
--- a/src/nsterm.h
+++ b/src/nsterm.h
@@ -23,6 +23,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include "character.h"
 #include "font.h"
 #include "sysselect.h"
+#include "sysstdio.h"
 
 #ifdef HAVE_NS
 #ifdef __OBJC__
@@ -180,7 +181,7 @@ char const * nstrace_fullscreen_type_name (int);
                    __FILE__, __LINE__, nstrace_num++,                       \
                    2*nstrace_depth, "  | | | | | | | | | | | | | | | ..");  \
           fprintf (stderr, __VA_ARGS__);                                    \
-          fprintf (stderr, "\n");                                           \
+          putc ('\n', stderr);                                              \
         }                                                                   \
     }                                                                       \
   while(0)
diff --git a/src/nsterm.m b/src/nsterm.m
index bc1c7860aac..02331826d9b 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -2466,7 +2466,7 @@ ns_mouse_position (struct frame **fp, int insist, Lisp_Object *bar_window,
 
   if (*fp == NULL)
     {
-      fprintf (stderr, "Warning: ns_mouse_position () called with null *fp.\n");
+      fputs ("Warning: ns_mouse_position () called with null *fp.\n", stderr);
       return;
     }
 
@@ -5613,7 +5613,7 @@ ns_term_shutdown (int sig)
 
   if (type == NSEventTypeCursorUpdate && window == nil)
     {
-      fprintf (stderr, "Dropping external cursor update event.\n");
+      fputs ("Dropping external cursor update event.\n", stderr);
       return;
     }
 
@@ -6333,7 +6333,7 @@ not_in_argv (NSString *arg)
      https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/EventOverview/HandlingKeyEvents/HandlingKeyEvents.html.  */
 
   if (NS_KEYLOG && !processingCompose)
-    fprintf (stderr, "keyDown: Begin compose sequence.\n");
+    fputs ("keyDown: Begin compose sequence.\n", stderr);
 
   /* FIXME: interpretKeyEvents doesn’t seem to send insertText if ⌘ is
      used as shift-like modifier, at least on El Capitan.  Mask it
@@ -8291,7 +8291,7 @@ not_in_argv (NSString *arg)
     }
   else
     {
-      fprintf (stderr, "Invalid data type in dragging pasteboard\n");
+      fputs ("Invalid data type in dragging pasteboard\n", stderr);
       return NO;
     }
 
diff --git a/src/pdumper.c b/src/pdumper.c
index c00f8a0af54..8b630d221b1 100644
--- a/src/pdumper.c
+++ b/src/pdumper.c
@@ -23,7 +23,6 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include <math.h>
 #include <stdarg.h>
 #include <stdint.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <sys/mman.h>
 #include <sys/param.h>
@@ -42,6 +41,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include "lisp.h"
 #include "pdumper.h"
 #include "window.h"
+#include "sysstdio.h"
 #include "systime.h"
 #include "thread.h"
 #include "bignum.h"
@@ -329,7 +329,7 @@ dump_fingerprint (const char *label, unsigned char const *xfingerprint)
   fprintf (stderr, "%s: ", label);
   for (int i = 0; i < 32; ++i)
     fprintf (stderr, "%02x", (unsigned) xfingerprint[i]);
-  fprintf (stderr, "\n");
+  putc ('\n', stderr);
 }
 
 /* Format of an Emacs portable dump file.  All offsets are relative to
@@ -1404,9 +1404,9 @@ print_paths_to_root_1 (struct dump_context *ctx,
       referrers = XCDR (referrers);
       Lisp_Object repr = Fprin1_to_string (referrer, Qnil);
       for (int i = 0; i < level; ++i)
-        fputc (' ', stderr);
+        putc (' ', stderr);
       fwrite (SDATA (repr), 1, SBYTES (repr), stderr);
-      fputc ('\n', stderr);
+      putc ('\n', stderr);
       print_paths_to_root_1 (ctx, referrer, level + 1);
     }
 }
@@ -4226,14 +4226,14 @@ types.  */)
   dump_seek (ctx, 0);
   dump_write (ctx, &ctx->header, sizeof (ctx->header));
 
-  fprintf (stderr, "Dump complete\n");
   fprintf (stderr,
-           "Byte counts: header=%lu hot=%lu discardable=%lu cold=%lu\n",
+           ("Dump complete\n"
+            "Byte counts: header=%lu hot=%lu discardable=%lu cold=%lu\n"
+            "Reloc counts: hot=%u discardable=%u\n"),
            (unsigned long) (header_end - header_start),
            (unsigned long) (hot_end - hot_start),
            (unsigned long) (discardable_end - ctx->header.discardable_start),
-           (unsigned long) (cold_end - ctx->header.cold_start));
-  fprintf (stderr, "Reloc counts: hot=%u discardable=%u\n",
+           (unsigned long) (cold_end - ctx->header.cold_start),
            number_hot_relocations,
            number_discardable_relocations);
 
diff --git a/src/print.c b/src/print.c
index dc44b1e89e0..6623244c598 100644
--- a/src/print.c
+++ b/src/print.c
@@ -233,7 +233,7 @@ printchar_to_stream (unsigned int ch, FILE *stream)
     {
       if (ASCII_CHAR_P (ch))
         {
-          putc_unlocked (ch, stream);
+          putc (ch, stream);
 #ifdef WINDOWSNT
           /* Send the output to a debugger (nothing happens if there
              isn't one).  */
@@ -251,7 +251,7 @@ printchar_to_stream (unsigned int ch, FILE *stream)
           if (encode_p)
             encoded_ch = code_convert_string_norecord (encoded_ch,
                                                        coding_system, true);
-          fwrite_unlocked (SSDATA (encoded_ch), 1, SBYTES (encoded_ch), stream);
+          fwrite (SSDATA (encoded_ch), 1, SBYTES (encoded_ch), stream);
 #ifdef WINDOWSNT
           if (print_output_debug_flag && stream == stderr)
             OutputDebugString (SSDATA (encoded_ch));
@@ -303,7 +303,7 @@ printchar (unsigned int ch, Lisp_Object fun)
           if (DISP_TABLE_P (Vstandard_display_table))
             printchar_to_stream (ch, stdout);
           else
-            fwrite_unlocked (str, 1, len, stdout);
+            fwrite (str, 1, len, stdout);
           noninteractive_need_newline = 1;
         }
       else
@@ -374,7 +374,7 @@ strout (const char *ptr, ptrdiff_t size, ptrdiff_t size_byte,
             }
         }
       else
-        fwrite_unlocked (ptr, 1, size_byte, stdout);
+        fwrite (ptr, 1, size_byte, stdout);
 
       noninteractive_need_newline = 1;
     }
@@ -825,7 +825,7 @@ append to existing target file.  */)
         report_file_error ("Cannot open debugging output stream", file);
     }
 
-  fflush_unlocked (stderr);
+  fflush (stderr);
   if (dup2 (fd, STDERR_FILENO) < 0)
     report_file_error ("dup2", file);
   if (fd != stderr_dup)
@@ -840,7 +840,7 @@ void
 debug_print (Lisp_Object arg)
 {
   Fprin1 (arg, Qexternal_debugging_output);
-  fprintf (stderr, "\r\n");
+  fputs ("\r\n", stderr);
 }
 
 void safe_debug_print (Lisp_Object) EXTERNALLY_VISIBLE;
diff --git a/src/regex-emacs.c b/src/regex-emacs.c
index ac9f91dacbc..bf2ad072f56 100644
--- a/src/regex-emacs.c
+++ b/src/regex-emacs.c
@@ -436,7 +436,7 @@ extract_number_and_incr (re_char **source)
 #ifdef REGEX_EMACS_DEBUG
 
 /* Use standard I/O for debugging.  */
-# include <stdio.h>
+# include "sysstdio.h"
 
 static int regex_emacs_debug = -100000;
 
@@ -453,7 +453,7 @@ static void
 debug_putchar (int c)
 {
   if (c >= 32 && c <= 126)
-    fputc (c, stderr);
+    putc (c, stderr);
   else
     {
       unsigned int uc = c;
@@ -482,12 +482,12 @@ print_fastmap (char *fastmap)
             }
           if (was_a_range)
             {
-              fprintf (stderr, "-");
+              debug_putchar ('-');
               debug_putchar (i - 1);
             }
         }
     }
-  fputc ('\n', stderr);
+  putc ('\n', stderr);
 }
 
 
@@ -503,7 +503,7 @@ print_partial_compiled_pattern (re_char *start, re_char *end)
 
   if (start == NULL)
     {
-      fprintf (stderr, "(null)\n");
+      fputs ("(null)\n", stderr);
       return;
     }
 
@@ -515,11 +515,11 @@ print_partial_compiled_pattern (re_char *start, re_char *end)
       switch ((re_opcode_t) *p++)
         {
         case no_op:
-          fprintf (stderr, "/no_op");
+          fputs ("/no_op", stderr);
           break;
 
         case succeed:
-          fprintf (stderr, "/succeed");
+          fputs ("/succeed", stderr);
           break;
 
         case exactn:
@@ -527,7 +527,7 @@ print_partial_compiled_pattern (re_char *start, re_char *end)
           fprintf (stderr, "/exactn/%d", mcnt);
           do
             {
-              fprintf (stderr, "/");
+              debug_putchar ('/');
               debug_putchar (*p++);
             }
           while (--mcnt);
@@ -546,7 +546,7 @@ print_partial_compiled_pattern (re_char *start, re_char *end)
           break;
 
         case anychar:
-          fprintf (stderr, "/anychar");
+          fputs ("/anychar", stderr);
           break;
 
         case charset:
@@ -561,7 +561,7 @@ print_partial_compiled_pattern (re_char *start, re_char *end)
                      (re_opcode_t) *(p - 1) == charset_not ? "^" : "");
 
             if (p + *p >= pend)
-              fprintf (stderr, " !extends past end of pattern! ");
+              fputs (" !extends past end of pattern! ", stderr);
 
             for (c = 0; c < 256; c++)
               if (c / 8 < length
@@ -570,7 +570,7 @@ print_partial_compiled_pattern (re_char *start, re_char *end)
                   /* Are we starting a range?  */
                   if (last + 1 == c && ! in_range)
                     {
-                      fprintf (stderr, "-");
+                      debug_putchar ('-');
                       in_range = true;
                     }
                   /* Have we broken a range?  */
@@ -589,14 +589,14 @@ print_partial_compiled_pattern (re_char *start, re_char *end)
             if (in_range)
               debug_putchar (last);
 
-            fprintf (stderr, "]");
+            debug_putchar (']');
 
             p += 1 + length;
 
             if (has_range_table)
               {
                 int count;
-                fprintf (stderr, "has-range-table");
+                fputs ("has-range-table", stderr);
 
                 /* ??? Should print the range table; for now, just skip it.  */
                 p += 2;         /* skip range table bits */
@@ -607,11 +607,11 @@ print_partial_compiled_pattern (re_char *start, re_char *end)
           break;
 
         case begline:
-          fprintf (stderr, "/begline");
+          fputs ("/begline", stderr);
           break;
 
         case endline:
-          fprintf (stderr, "/endline");
+          fputs ("/endline", stderr);
           break;
 
         case on_failure_jump:
@@ -670,70 +670,70 @@ print_partial_compiled_pattern (re_char *start, re_char *end)
           break;
 
         case wordbound:
-          fprintf (stderr, "/wordbound");
+          fputs ("/wordbound", stderr);
           break;
 
         case notwordbound:
-          fprintf (stderr, "/notwordbound");
+          fputs ("/notwordbound", stderr);
           break;
 
         case wordbeg:
-          fprintf (stderr, "/wordbeg");
+          fputs ("/wordbeg", stderr);
           break;
 
         case wordend:
-          fprintf (stderr, "/wordend");
+          fputs ("/wordend", stderr);
           break;
 
         case symbeg:
-          fprintf (stderr, "/symbeg");
+          fputs ("/symbeg", stderr);
           break;
 
         case symend:
-          fprintf (stderr, "/symend");
+          fputs ("/symend", stderr);
           break;
 
         case syntaxspec:
-          fprintf (stderr, "/syntaxspec");
+          fputs ("/syntaxspec", stderr);
           mcnt = *p++;
           fprintf (stderr, "/%d", mcnt);
           break;
 
         case notsyntaxspec:
-          fprintf (stderr, "/notsyntaxspec");
+          fputs ("/notsyntaxspec", stderr);
           mcnt = *p++;
           fprintf (stderr, "/%d", mcnt);
           break;
 
         case at_dot:
-          fprintf (stderr, "/at_dot");
+          fputs ("/at_dot", stderr);
           break;
 
         case categoryspec:
-          fprintf (stderr, "/categoryspec");
+          fputs ("/categoryspec", stderr);
           mcnt = *p++;
           fprintf (stderr, "/%d", mcnt);
           break;
 
         case notcategoryspec:
-          fprintf (stderr, "/notcategoryspec");
+          fputs ("/notcategoryspec", stderr);
           mcnt = *p++;
           fprintf (stderr, "/%d", mcnt);
           break;
 
         case begbuf:
-          fprintf (stderr, "/begbuf");
+          fputs ("/begbuf", stderr);
           break;
 
         case endbuf:
-          fprintf (stderr, "/endbuf");
+          fputs ("/endbuf", stderr);
           break;
 
         default:
           fprintf (stderr, "?%d", *(p-1));
         }
 
-      fprintf (stderr, "\n");
+      putc ('\n', stderr);
     }
 
   fprintf (stderr, "%td:\tend of pattern.\n", p - start);
@@ -751,14 +751,13 @@ print_compiled_pattern (struct re_pattern_buffer *bufp)
 
   if (bufp->fastmap_accurate && bufp->fastmap)
     {
-      fprintf (stderr, "fastmap: ");
+      fputs ("fastmap: ", stderr);
       print_fastmap (bufp->fastmap);
     }
 
   fprintf (stderr, "re_nsub: %td\t", bufp->re_nsub);
   fprintf (stderr, "regs_alloc: %d\t", bufp->regs_allocated);
   fprintf (stderr, "can_be_null: %d\n", bufp->can_be_null);
-  fflush (stderr);
   /* Perhaps we should print the translate table?  */
 }
 
@@ -768,7 +767,7 @@ print_double_string (re_char *where, re_char *string1, ptrdiff_t size1,
                      re_char *string2, ptrdiff_t size2)
 {
   if (where == NULL)
-    fprintf (stderr, "(null)");
+    fputs ("(null)", stderr);
   else
     {
       int i;
@@ -1751,7 +1750,7 @@ regex_compile (re_char *pattern, ptrdiff_t size,
     {
       for (ptrdiff_t debug_count = 0; debug_count < size; debug_count++)
         debug_putchar (pattern[debug_count]);
-      fputc ('\n', stderr);
+      putc ('\n', stderr);
     }
 #endif
 
diff --git a/src/sysdep.c b/src/sysdep.c
index c7d7eefc2ab..99d3ee60698 100644
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -1472,7 +1472,7 @@ reset_sys_modes (struct tty_display_info *tty_out)
 {
   if (noninteractive)
     {
-      fflush_unlocked (stdout);
+      fflush (stdout);
       return;
     }
   if (!tty_out->term_initted)
@@ -1495,11 +1495,11 @@ reset_sys_modes (struct tty_display_info *tty_out)
       tty_turn_off_insert (tty_out);
 
       for (int i = cursorX (tty_out); i < FrameCols (tty_out) - 1; i++)
-        fputc_unlocked (' ', tty_out->output);
+        putc (' ', tty_out->output);
     }
 
   cmgoto (tty_out, FrameRows (tty_out) - 1, 0);
-  fflush_unlocked (tty_out->output);
+  fflush (tty_out->output);
 
   if (tty_out->terminal->reset_terminal_modes_hook)
     tty_out->terminal->reset_terminal_modes_hook (tty_out->terminal);
@@ -2783,7 +2783,7 @@ close_output_streams (void)
   /* Do not close stderr if addresses are being sanitized, as the
      sanitizer might report to stderr after this function is invoked.  */
   if (ADDRESS_SANITIZER
-      ? fflush_unlocked (stderr) != 0 || ferror (stderr)
+      ? fflush (stderr) != 0 || ferror (stderr)
       : close_stream (stderr) != 0)
     _exit (EXIT_FAILURE);
 }
@@ -3184,7 +3184,7 @@ procfs_ttyname (int rdev)
       char minor[25];   /* 2 32-bit numbers + dash */
       char *endp;
 
-      for (; !feof_unlocked (fdev) && !ferror_unlocked (fdev); name[0] = 0)
+      for (; !feof (fdev) && !ferror (fdev); name[0] = 0)
         {
           if (fscanf (fdev, "%*s %s %u %s %*s\n", name, &major, minor) >= 3
               && major == MAJOR (rdev))
@@ -3234,7 +3234,7 @@ procfs_get_total_memory (void)
             break;
 
           case 0:
-            while ((c = getc_unlocked (fmem)) != EOF && c != '\n')
+            while ((c = getc (fmem)) != EOF && c != '\n')
               continue;
             done = c == EOF;
             break;
diff --git a/src/sysstdio.h b/src/sysstdio.h
index a2364c4e1fb..68ae043fe33 100644
--- a/src/sysstdio.h
+++ b/src/sysstdio.h
@@ -22,6 +22,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #include <fcntl.h>
 #include <stdio.h>
+#include "unlocked-io.h"
 
 extern FILE *emacs_fopen (char const *, char const *);
 extern void close_output_streams (void);
@@ -34,45 +35,4 @@ extern void close_output_streams (void);
 # define FOPEN_TEXT ""
 #endif
 
-/* These are compatible with unlocked-io.h, if both files are included.  */
-#if !HAVE_DECL_CLEARERR_UNLOCKED
-# define clearerr_unlocked(x) clearerr (x)
-#endif
-#if !HAVE_DECL_FEOF_UNLOCKED
-# define feof_unlocked(x) feof (x)
-#endif
-#if !HAVE_DECL_FERROR_UNLOCKED
-# define ferror_unlocked(x) ferror (x)
-#endif
-#if !HAVE_DECL_FFLUSH_UNLOCKED
-# define fflush_unlocked(x) fflush (x)
-#endif
-#if !HAVE_DECL_FGETS_UNLOCKED
-# define fgets_unlocked(x,y,z) fgets (x,y,z)
-#endif
-#if !HAVE_DECL_FPUTC_UNLOCKED
-# define fputc_unlocked(x,y) fputc (x,y)
-#endif
-#if !HAVE_DECL_FPUTS_UNLOCKED
-# define fputs_unlocked(x,y) fputs (x,y)
-#endif
-#if !HAVE_DECL_FREAD_UNLOCKED
-# define fread_unlocked(w,x,y,z) fread (w,x,y,z)
-#endif
-#if !HAVE_DECL_FWRITE_UNLOCKED
-# define fwrite_unlocked(w,x,y,z) fwrite (w,x,y,z)
-#endif
-#if !HAVE_DECL_GETC_UNLOCKED
-# define getc_unlocked(x) getc (x)
-#endif
-#if !HAVE_DECL_GETCHAR_UNLOCKED
-# define getchar_unlocked() getchar ()
-#endif
-#if !HAVE_DECL_PUTC_UNLOCKED
-# define putc_unlocked(x,y) putc (x,y)
-#endif
-#if !HAVE_DECL_PUTCHAR_UNLOCKED
-# define putchar_unlocked(x) putchar (x)
-#endif
-
 #endif /* EMACS_SYSSTDIO_H */
diff --git a/src/term.c b/src/term.c
index 8b5a710d80a..b058d8bdad0 100644
--- a/src/term.c
+++ b/src/term.c
@@ -145,7 +145,7 @@ tty_ring_bell (struct frame *f)
       OUTPUT (tty, (tty->TS_visible_bell && visible_bell
                     ? tty->TS_visible_bell
                     : tty->TS_bell));
-      fflush_unlocked (tty->output);
+      fflush (tty->output);
     }
 }
 
@@ -170,10 +170,9 @@ tty_send_additional_strings (struct terminal *terminal, Lisp_Object sym)
       Lisp_Object string = XCAR (extra_codes);
       if (STRINGP (string))
         {
-          fwrite_unlocked (SDATA (string), 1, SBYTES (string), tty->output);
+          fwrite (SDATA (string), 1, SBYTES (string), tty->output);
           if (tty->termscript)
-            fwrite_unlocked (SDATA (string), 1, SBYTES (string),
-                             tty->termscript);
+            fwrite (SDATA (string), 1, SBYTES (string), tty->termscript);
         }
     }
 }
@@ -201,7 +200,7 @@ tty_set_terminal_modes (struct terminal *terminal)
       OUTPUT_IF (tty, tty->TS_keypad_mode);
       losecursor (tty);
       tty_send_additional_strings (terminal, Qtty_mode_set_strings);
-      fflush_unlocked (tty->output);
+      fflush (tty->output);
     }
 }
 
@@ -224,7 +223,7 @@ tty_reset_terminal_modes (struct terminal *terminal)
       /* Output raw CR so kernel can track the cursor hpos.  */
       current_tty = tty;
       cmputc ('\r');
-      fflush_unlocked (tty->output);
+      fflush (tty->output);
     }
 }
 
@@ -239,7 +238,7 @@ tty_update_end (struct frame *f)
     tty_show_cursor (tty);
   tty_turn_off_insert (tty);
   tty_background_highlight (tty);
-  fflush_unlocked (tty->output);
+  fflush (tty->output);
 }
 
 /* The implementation of set_terminal_window for termcap frames. */
@@ -501,8 +500,8 @@ tty_clear_end_of_line (struct frame *f, int first_unused_hpos)
       for (i = curX (tty); i < first_unused_hpos; i++)
         {
           if (tty->termscript)
-            fputc_unlocked (' ', tty->termscript);
-          fputc_unlocked (' ', tty->output);
+            putc (' ', tty->termscript);
+          putc (' ', tty->output);
         }
       cmplus (tty, first_unused_hpos - curX (tty));
     }
@@ -775,11 +774,10 @@ tty_write_glyphs (struct frame *f, struct glyph *string, int len)
       if (coding->produced > 0)
         {
           block_input ();
-          fwrite_unlocked (conversion_buffer, 1, coding->produced, tty->output);
-          clearerr_unlocked (tty->output);
+          fwrite (conversion_buffer, 1, coding->produced, tty->output);
+          clearerr (tty->output);
           if (tty->termscript)
-            fwrite_unlocked (conversion_buffer, 1, coding->produced,
-                             tty->termscript);
+            fwrite (conversion_buffer, 1, coding->produced, tty->termscript);
           unblock_input ();
         }
       string += n;
@@ -836,11 +834,10 @@ tty_write_glyphs_with_face (register struct frame *f, register struct glyph *str
   if (coding->produced > 0)
     {
       block_input ();
-      fwrite_unlocked (conversion_buffer, 1, coding->produced, tty->output);
-      clearerr_unlocked (tty->output);
+      fwrite (conversion_buffer, 1, coding->produced, tty->output);
+      clearerr (tty->output);
       if (tty->termscript)
-        fwrite_unlocked (conversion_buffer, 1, coding->produced,
-                         tty->termscript);
+        fwrite (conversion_buffer, 1, coding->produced, tty->termscript);
       unblock_input ();
     }
 
@@ -922,11 +919,10 @@ tty_insert_glyphs (struct frame *f, struct glyph *start, int len)
       if (coding->produced > 0)
         {
           block_input ();
-          fwrite_unlocked (conversion_buffer, 1, coding->produced, tty->output);
-          clearerr_unlocked (tty->output);
+          fwrite (conversion_buffer, 1, coding->produced, tty->output);
+          clearerr (tty->output);
           if (tty->termscript)
-            fwrite_unlocked (conversion_buffer, 1, coding->produced,
-                             tty->termscript);
+            fwrite (conversion_buffer, 1, coding->produced, tty->termscript);
           unblock_input ();
         }
 
@@ -3331,7 +3327,7 @@ tty_menu_activate (tty_menu *menu, int *pane, int *selidx,
          which calls tty_show_cursor.  Re-hide it, so it doesn't show
          through the menus.  */
       tty_hide_cursor (tty);
-      fflush_unlocked (tty->output);
+      fflush (tty->output);
     }
 
   sf->mouse_moved = 0;
@@ -3339,7 +3335,7 @@ tty_menu_activate (tty_menu *menu, int *pane, int *selidx,
   while (statecount--)
     free_saved_screen (state[statecount].screen_behind);
   tty_show_cursor (tty);        /* Turn cursor back on.  */
-  fflush_unlocked (tty->output);
+  fflush (tty->output);
 
 /* Clean up any mouse events that are waiting inside Emacs event queue.
      These events are likely to be generated before the menu was even
@@ -4398,10 +4394,10 @@ use the Bourne shell command 'TERM=...; export TERM' (C-shell:\n\
 static void
 vfatal (const char *str, va_list ap)
 {
-  fprintf (stderr, "emacs: ");
+  fputs ("emacs: ", stderr);
   vfprintf (stderr, str, ap);
   if (! (str[0] && str[strlen (str) - 1] == '\n'))
-    fprintf (stderr, "\n");
+    putc ('\n', stderr);
   exit (1);
 }
 
diff --git a/src/unexhp9k800.c b/src/unexhp9k800.c
index cbf1835b9ee..d2943eb18c9 100644
--- a/src/unexhp9k800.c
+++ b/src/unexhp9k800.c
@@ -52,8 +52,8 @@
 #include <config.h>
 #include "unexec.h"
 #include "lisp.h"
+#include "sysstdio.h"
 
-#include <stdio.h>
 #include <fcntl.h>
 #include <errno.h>
 #include <a.out.h>
@@ -167,7 +167,7 @@ read_header (int file, struct header *hdr, struct som_exec_auxhdr *auxhdr)
   if (hdr->a_magic != EXEC_MAGIC && hdr->a_magic != SHARE_MAGIC
       &&  hdr->a_magic != DEMAND_MAGIC)
     {
-      fprintf (stderr, "a.out file doesn't have valid magic number\n");
+      fputs ("a.out file doesn't have valid magic number\n", stderr);
       exit (1);
     }
 
diff --git a/src/unexmacosx.c b/src/unexmacosx.c
index a94c0cccb6b..5f52cedb2b7 100644
--- a/src/unexmacosx.c
+++ b/src/unexmacosx.c
@@ -97,9 +97,9 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #include "unexec.h"
 #include "lisp.h"
+#include "sysstdio.h"
 
 #include <errno.h>
-#include <stdio.h>
 #include <fcntl.h>
 #include <stdarg.h>
 #include <stdint.h>
@@ -303,9 +303,9 @@ unexec_error (const char *format, ...)
   va_list ap;
 
   va_start (ap, format);
-  fprintf (stderr, "unexec: ");
+  fputs ("unexec: ", stderr);
   vfprintf (stderr, format, ap);
-  fprintf (stderr, "\n");
+  putc ('\n', stderr);
   va_end (ap);
   exit (1);
 }
diff --git a/src/widget.c b/src/widget.c
index e662dd3ecdf..c3d396ddab0 100644
--- a/src/widget.c
+++ b/src/widget.c
@@ -31,10 +31,10 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include "widget.h"
 
-#include <stdio.h>
 #include <stdlib.h>
 
 #include "lisp.h"
+#include "sysstdio.h"
 #include "xterm.h"
 #include "frame.h"
 
@@ -364,8 +364,7 @@ EmacsFrameInitialize (Widget request, Widget new, ArgList dum1, Cardinal *dum2)
 
   if (!ew->emacs_frame.frame)
     {
-      fprintf (stderr,
-               "can't create an emacs frame widget without a frame\n");
+      fputs ("can't create an emacs frame widget without a frame\n", stderr);
       exit (1);
     }
 
diff --git a/src/xdisp.c b/src/xdisp.c
index 75cc97df1c0..2711e54382d 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -302,7 +302,6 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
    buffer_posn_from_coords in dispnew.c for how this is handled.  */
 
 #include <config.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <limits.h>
 #include <math.h>
@@ -311,6 +310,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include "atimer.h"
 #include "composite.h"
 #include "keyboard.h"
+#include "sysstdio.h"
 #include "systime.h"
 #include "frame.h"
 #include "window.h"
@@ -10714,7 +10714,7 @@ message_to_stderr (Lisp_Object m)
   if (noninteractive_need_newline)
     {
       noninteractive_need_newline = false;
-      fputc ('\n', stderr);
+      putc ('\n', stderr);
     }
   if (STRINGP (m))
     {
@@ -10728,7 +10728,7 @@ message_to_stderr (Lisp_Object m)
       else
         s = m;
 
-      /* We want to write this out with a single fwrite call so that
+      /* We want to write this out with a single call so that
          output doesn't interleave with other processes writing to
          stderr at the same time. */
       {
@@ -10742,9 +10742,7 @@ message_to_stderr (Lisp_Object m)
       }
     }
   else if (!cursor_in_echo_area)
-    fputc ('\n', stderr);
-
-  fflush (stderr);
+    putc ('\n', stderr);
 }
 
 /* The non-logging version of message3.
@@ -10889,11 +10887,11 @@ vmessage (const char *m, va_list ap)
       if (m)
         {
           if (noninteractive_need_newline)
-            fputc ('\n', stderr);
+            putc ('\n', stderr);
           noninteractive_need_newline = false;
           vfprintf (stderr, m, ap);
           if (!cursor_in_echo_area)
-            fputc ('\n', stderr);
+            putc ('\n', stderr);
           fflush (stderr);
         }
     }
@@ -19648,9 +19646,9 @@ dump_glyph_row (struct glyph_row *row, int vpos, int glyphs)
 {
   if (glyphs != 1)
     {
-      fprintf (stderr, "Row     Start       End Used oE><\\CTZFesm     X    Y    W    H    V    A    P\n");
-      fprintf (stderr, "==============================================================================\n");
-
+      fputs (("Row     Start       End Used oE><\\CTZFesm     X    Y    W    H    V    A    P\n"
+              "==============================================================================\n"),
+             stderr);
       fprintf (stderr, "%3d %9"pD"d %9"pD"d %4d %1.1d%1.1d%1.1d%1.1d\
 %1.1d%1.1d%1.1d%1.1d%1.1d%1.1d%1.1d%1.1d  %4d %4d %4d %4d %4d %4d %4d\n",
                vpos,
@@ -19701,7 +19699,8 @@ dump_glyph_row (struct glyph_row *row, int vpos, int glyphs)
             ++glyph_end;
 
           if (glyph < glyph_end)
-            fprintf (stderr, " Glyph#  Type       Pos   O   W     Code      C Face LR\n");
+            fputs (" Glyph#  Type       Pos   O   W     Code      C Face LR\n",
+                   stderr);
 
           for (; glyph < glyph_end; ++glyph)
             dump_glyph (row, glyph, area);
@@ -19761,7 +19760,7 @@ with numeric argument, its value is passed as the GLYPHS flag.  */)
            BUF_PT (buffer), BUF_BEGV (buffer), BUF_ZV (buffer));
   fprintf (stderr, "Cursor x = %d, y = %d, hpos = %d, vpos = %d\n",
            w->cursor.x, w->cursor.y, w->cursor.hpos, w->cursor.vpos);
-  fprintf (stderr, "=============================================\n");
+  fputs ("=============================================\n", stderr);
   dump_glyph_matrix (w->current_matrix,
                      TYPE_RANGED_FIXNUMP (int, glyphs) ? XFIXNUM (glyphs) : 0);
   return Qnil;
@@ -19778,7 +19777,7 @@ Only text-mode frames have frame glyph matrices.  */)
   if (f->current_matrix)
     dump_glyph_matrix (f->current_matrix, 1);
   else
-    fprintf (stderr, "*** This frame doesn't have a frame glyph matrix ***\n");
+    fputs ("*** This frame doesn't have a frame glyph matrix ***\n", stderr);
   return Qnil;
 }
 
@@ -25974,7 +25973,7 @@ extern void dump_glyph_string (struct glyph_string *) EXTERNALLY_VISIBLE;
 void
 dump_glyph_string (struct glyph_string *s)
 {
-  fprintf (stderr, "glyph string\n");
+  fputs ("glyph string\n", stderr);
   fprintf (stderr, "  x, y, w, h = %d, %d, %d, %d\n",
            s->x, s->y, s->width, s->height);
   fprintf (stderr, "  ybase = %d\n", s->ybase);
diff --git a/src/xfaces.c b/src/xfaces.c
index d9e66eaf2d1..c3cae7e2a68 100644
--- a/src/xfaces.c
+++ b/src/xfaces.c
@@ -418,21 +418,18 @@ DEFUN ("dump-colors", Fdump_colors, Sdump_colors, 0, 0, 0,
 {
   int i, n;
 
-  fputc ('\n', stderr);
+  putc ('\n', stderr);
 
   for (i = n = 0; i < ARRAYELTS (color_count); ++i)
     if (color_count[i])
       {
         fprintf (stderr, "%3d: %5d", i, color_count[i]);
         ++n;
-        if (n % 5 == 0)
-          fputc ('\n', stderr);
-        else
-          fputc ('\t', stderr);
+        putc (n % 5 == 0 ? '\n' : '\t', stderr);
       }
 
   if (n % 5 != 0)
-    fputc ('\n', stderr);
+    putc ('\n', stderr);
   return Qnil;
 }
 
@@ -6363,7 +6360,7 @@ where R,G,B are numbers between 0 and 255 and name is an arbitrary string.  */)
       int red, green, blue;
       int num;
 
-      while (fgets_unlocked (buf, sizeof (buf), fp) != NULL) {
+      while (fgets (buf, sizeof (buf), fp) != NULL)
         if (sscanf (buf, "%d %d %d %n", &red, &green, &blue, &num) == 3)
           {
 #ifdef HAVE_NTGUI
@@ -6377,7 +6374,6 @@ where R,G,B are numbers between 0 and 255 and name is an arbitrary string.  */)
             cmap = Fcons (Fcons (make_string (name, len), make_fixnum (color)),
                           cmap);
           }
-      }
       fclose (fp);
     }
   unblock_input ();
@@ -6429,14 +6425,14 @@ DEFUN ("dump-face", Fdump_face, Sdump_face, 0, 1, 0, doc: /* */)
     {
       int i;
 
-      fprintf (stderr, "font selection order: ");
+      fputs ("font selection order: ", stderr);
       for (i = 0; i < ARRAYELTS (font_sort_order); ++i)
         fprintf (stderr, "%d ", font_sort_order[i]);
-      fprintf (stderr, "\n");
+      putc ('\n', stderr);
 
-      fprintf (stderr, "alternative fonts: ");
+      fputs ("alternative fonts: ", stderr);
       debug_print (Vface_alternative_font_family_alist);
-      fprintf (stderr, "\n");
+      putc ('\n', stderr);
 
       for (i = 0; i < FRAME_FACE_CACHE (SELECTED_FRAME ())->used; ++i)
         Fdump_face (make_fixnum (i));
diff --git a/src/xselect.c b/src/xselect.c
index ed68e4b1a6d..d74f064a1c7 100644
--- a/src/xselect.c
+++ b/src/xselect.c
@@ -21,7 +21,6 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #include <config.h>
 #include <limits.h>
-#include <stdio.h>      /* TRACE_SELECTION needs this.  */
 
 #ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
@@ -33,6 +32,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include "xterm.h"      /* for all of the X includes */
 #include "frame.h"      /* Need this to get the X window of selected_frame */
 #include "blockinput.h"
+#include "sysstdio.h"   /* TRACE_SELECTION needs this.  */
 #include "termhooks.h"
 #include "keyboard.h"
 #include "pdumper.h"
@@ -2172,9 +2172,10 @@ If the problem persists, set `%s' to nil.");
 static Lisp_Object
 x_clipboard_manager_error_2 (Lisp_Object err)
 {
-  fprintf (stderr, "Error saving to X clipboard manager.\n\
-If the problem persists, set '%s' \
-to nil.\n", "x-select-enable-clipboard-manager");
+  fputs (("Error saving to X clipboard manager.\n"
+          "If the problem persists,"
+          " set 'x-select-enable-clipboard-manager' to nil.\n"),
+         stderr);
   return Qnil;
 }
 
diff --git a/src/xterm.c b/src/xterm.c
index 38bc17de973..c96aa74a7a6 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -21,12 +21,12 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 /* Xt features made by Fred Pierresteguy.  */
 
 #include <config.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <math.h>
 
 #include "lisp.h"
 #include "blockinput.h"
+#include "sysstdio.h"
 
 /* This may include sys/types.h, and that somehow loses
    if this is not done before the other system files.  */
@@ -13441,8 +13441,8 @@ x_initialize (void)
 #if THREADS_ENABLED
   /* This must be called before any other Xlib routines.  */
   if (XInitThreads () == 0)
-    fprintf (stderr,
-             "Warning: An error occurred initializing X11 thread support!\n");
+    fputs ("Warning: An error occurred initializing X11 thread support!\n",
+           stderr);
 #endif
 
 #ifdef USE_X_TOOLKIT
diff --git a/src/xwidget.c b/src/xwidget.c
index 2486a2d4da8..121510ebac0 100644
--- a/src/xwidget.c
+++ b/src/xwidget.c
@@ -26,6 +26,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include "frame.h"
 #include "keyboard.h"
 #include "gtkutil.h"
+#include "sysstdio.h"
 
 #include <webkit2/webkit2.h>
 #include <JavaScriptCore/JavaScript.h>
@@ -690,7 +691,8 @@ x_draw_xwidget_glyph_string (struct glyph_string *s)
   struct xwidget *xw = XXWIDGET (xwidget);                              \
   if (!xw->widget_osr || !WEBKIT_IS_WEB_VIEW (xw->widget_osr))          \
     {                                                                   \
-      printf ("ERROR xw->widget_osr does not hold a webkit instance\n"); \
+      fputs ("ERROR xw->widget_osr does not hold a webkit instance\n",  \
+             stdout);                                                   \
       return Qnil;                                                      \
     }