1 files changed, 288 insertions, 70 deletions

diff --git a/gl/m4/mbrtowc.m4 b/gl/m4/mbrtowc.m4
index 4c9f3886..1d4e73d7 100644
--- a/gl/m4/mbrtowc.m4
+++ b/gl/m4/mbrtowc.m4
@@ -1,5 +1,5 @@
-# mbrtowc.m4 serial 25
-dnl Copyright (C) 2001-2002, 2004-2005, 2008-2013 Free Software Foundation,
+# mbrtowc.m4 serial 38  -*- coding: utf-8 -*-
+dnl Copyright (C) 2001-2002, 2004-2005, 2008-2021 Free Software Foundation,
 dnl Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -8,6 +8,8 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_FUNC_MBRTOWC],
 [
   AC_REQUIRE([gl_WCHAR_H_DEFAULTS])
+  AC_REQUIRE([gl_PTHREADLIB])
+  AC_CHECK_HEADERS_ONCE([threads.h])
 
   AC_REQUIRE([AC_TYPE_MBSTATE_T])
   gl_MBSTATE_T_BROKEN
@@ -16,15 +18,8 @@ AC_DEFUN([gl_FUNC_MBRTOWC],
   if test $ac_cv_func_mbrtowc = no; then
     HAVE_MBRTOWC=0
     AC_CHECK_DECLS([mbrtowc],,, [[
-/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
-   <wchar.h>.
-   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
-   included before <wchar.h>.  */
-#include <stddef.h>
-#include <stdio.h>
-#include <time.h>
-#include <wchar.h>
-]])
+      #include <wchar.h>
+    ]])
     if test $ac_cv_have_decl_mbrtowc = yes; then
       dnl On Minix 3.1.8, the system's <wchar.h> declares mbrtowc() although
       dnl it does not have the function. Avoid a collision with gnulib's
@@ -39,6 +34,9 @@ AC_DEFUN([gl_FUNC_MBRTOWC],
       gl_MBRTOWC_NULL_ARG2
       gl_MBRTOWC_RETVAL
       gl_MBRTOWC_NUL_RETVAL
+      gl_MBRTOWC_STORES_INCOMPLETE
+      gl_MBRTOWC_EMPTY_INPUT
+      gl_MBRTOWC_C_LOCALE
       case "$gl_cv_func_mbrtowc_null_arg1" in
         *yes) ;;
         *) AC_DEFINE([MBRTOWC_NULL_ARG1_BUG], [1],
@@ -67,8 +65,47 @@ AC_DEFUN([gl_FUNC_MBRTOWC],
            REPLACE_MBRTOWC=1
            ;;
       esac
+      case "$gl_cv_func_mbrtowc_stores_incomplete" in
+        *no) ;;
+        *) AC_DEFINE([MBRTOWC_STORES_INCOMPLETE_BUG], [1],
+             [Define if the mbrtowc function stores a wide character when reporting incomplete input.])
+           REPLACE_MBRTOWC=1
+           ;;
+      esac
+      case "$gl_cv_func_mbrtowc_empty_input" in
+        *yes) ;;
+        *) AC_DEFINE([MBRTOWC_EMPTY_INPUT_BUG], [1],
+             [Define if the mbrtowc function does not return (size_t) -2
+              for empty input.])
+           REPLACE_MBRTOWC=1
+           ;;
+      esac
+      case "$gl_cv_func_mbrtowc_C_locale_sans_EILSEQ" in
+        *yes) ;;
+        *) AC_DEFINE([MBRTOWC_IN_C_LOCALE_MAYBE_EILSEQ], [1],
+             [Define if the mbrtowc function may signal encoding errors in the C locale.])
+           REPLACE_MBRTOWC=1
+           ;;
+      esac
     fi
   fi
+  if test $REPLACE_MBSTATE_T = 1; then
+    case "$host_os" in
+      mingw*) LIB_MBRTOWC= ;;
+      *)
+        gl_WEAK_SYMBOLS
+        case "$gl_cv_have_weak" in
+          *yes) LIB_MBRTOWC= ;;
+          *)    LIB_MBRTOWC="$LIBPTHREAD" ;;
+        esac
+        ;;
+    esac
+  else
+    LIB_MBRTOWC=
+  fi
+  dnl LIB_MBRTOWC is expected to be '-pthread' or '-lpthread' on AIX
+  dnl with gcc or xlc, and empty otherwise.
+  AC_SUBST([LIB_MBRTOWC])
 ])
 
 dnl Test whether mbsinit() and mbrtowc() need to be overridden in a way that
@@ -80,11 +117,19 @@ dnl avoid inconsistencies.
 AC_DEFUN([gl_MBSTATE_T_BROKEN],
 [
   AC_REQUIRE([gl_WCHAR_H_DEFAULTS])
+  AC_REQUIRE([AC_CANONICAL_HOST])
 
   AC_REQUIRE([AC_TYPE_MBSTATE_T])
   AC_CHECK_FUNCS_ONCE([mbsinit])
   AC_CHECK_FUNCS_ONCE([mbrtowc])
-  if test $ac_cv_func_mbsinit = yes && test $ac_cv_func_mbrtowc = yes; then
+  dnl On native Windows, we know exactly how mbsinit() behaves and don't need
+  dnl to override it, even if - like on MSVC - mbsinit() is only defined as
+  dnl an inline function, not as a global function.
+  if case "$host_os" in
+       mingw*) true ;;
+       *) test $ac_cv_func_mbsinit = yes ;;
+     esac \
+    && test $ac_cv_func_mbrtowc = yes; then
     gl_MBRTOWC_INCOMPLETE_STATE
     gl_MBRTOWC_SANITYCHECK
     REPLACE_MBSTATE_T=0
@@ -109,6 +154,7 @@ AC_DEFUN([gl_MBRTOWC_INCOMPLETE_STATE],
 [
   AC_REQUIRE([AC_PROG_CC])
   AC_REQUIRE([gt_LOCALE_JA])
+  AC_REQUIRE([gt_LOCALE_FR_UTF8])
   AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   AC_CACHE_CHECK([whether mbrtowc handles incomplete characters],
     [gl_cv_func_mbrtowc_incomplete_state],
@@ -128,13 +174,6 @@ changequote([,])dnl
           [AC_LANG_SOURCE([[
 #include <locale.h>
 #include <string.h>
-/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
-   <wchar.h>.
-   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
-   included before <wchar.h>.  */
-#include <stddef.h>
-#include <stdio.h>
-#include <time.h>
 #include <wchar.h>
 int main ()
 {
@@ -147,13 +186,39 @@ int main ()
       memset (&state, '\0', sizeof (mbstate_t));
       if (mbrtowc (&wc, input + 1, 1, &state) == (size_t)(-2))
         if (mbsinit (&state))
-          return 1;
+          return 2;
+    }
+  return 0;
+}]])],
+          [gl_cv_func_mbrtowc_incomplete_state=yes],
+          [gl_cv_func_mbrtowc_incomplete_state=no],
+          [:])
+      else
+        if test $LOCALE_FR_UTF8 != none; then
+          AC_RUN_IFELSE(
+            [AC_LANG_SOURCE([[
+#include <locale.h>
+#include <string.h>
+#include <wchar.h>
+int main ()
+{
+  if (setlocale (LC_ALL, "$LOCALE_FR_UTF8") != NULL)
+    {
+      const char input[] = "B\303\274\303\237er"; /* "Büßer" */
+      mbstate_t state;
+      wchar_t wc;
+
+      memset (&state, '\0', sizeof (mbstate_t));
+      if (mbrtowc (&wc, input + 1, 1, &state) == (size_t)(-2))
+        if (mbsinit (&state))
+          return 2;
     }
   return 0;
 }]])],
           [gl_cv_func_mbrtowc_incomplete_state=yes],
           [gl_cv_func_mbrtowc_incomplete_state=no],
           [:])
+        fi
       fi
     ])
 ])
@@ -185,13 +250,6 @@ changequote([,])dnl
 #include <locale.h>
 #include <stdlib.h>
 #include <string.h>
-/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
-   <wchar.h>.
-   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
-   included before <wchar.h>.  */
-#include <stddef.h>
-#include <stdio.h>
-#include <time.h>
 #include <wchar.h>
 int main ()
 {
@@ -207,7 +265,7 @@ int main ()
       memset (&state, '\0', sizeof (mbstate_t));
       if (mbrtowc (&wc, input + 3, 6, &state) != 4
           && mbtowc (&wc, input + 3, 6) == 4)
-        return 1;
+        return 2;
     }
   return 0;
 }]])],
@@ -245,13 +303,6 @@ changequote([,])dnl
 #include <locale.h>
 #include <stdlib.h>
 #include <string.h>
-/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
-   <wchar.h>.
-   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
-   included before <wchar.h>.  */
-#include <stddef.h>
-#include <stdio.h>
-#include <time.h>
 #include <wchar.h>
 int main ()
 {
@@ -314,13 +365,6 @@ changequote([,])dnl
           [AC_LANG_SOURCE([[
 #include <locale.h>
 #include <string.h>
-/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
-   <wchar.h>.
-   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
-   included before <wchar.h>.  */
-#include <stddef.h>
-#include <stdio.h>
-#include <time.h>
 #include <wchar.h>
 int main ()
 {
@@ -335,7 +379,7 @@ int main ()
       mbrtowc (&wc, NULL, 5, &state);
       /* Check that wc was not modified.  */
       if (wc != (wchar_t) 0xBADFACE)
-        return 1;
+        return 2;
     }
   return 0;
 }]])],
@@ -376,13 +420,6 @@ changequote([,])dnl
           [AC_LANG_SOURCE([[
 #include <locale.h>
 #include <string.h>
-/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
-   <wchar.h>.
-   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
-   included before <wchar.h>.  */
-#include <stddef.h>
-#include <stdio.h>
-#include <time.h>
 #include <wchar.h>
 int main ()
 {
@@ -504,13 +541,6 @@ changequote([,])dnl
           [AC_LANG_SOURCE([[
 #include <locale.h>
 #include <string.h>
-/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
-   <wchar.h>.
-   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
-   included before <wchar.h>.  */
-#include <stddef.h>
-#include <stdio.h>
-#include <time.h>
 #include <wchar.h>
 int main ()
 {
@@ -522,7 +552,7 @@ int main ()
 
       memset (&state, '\0', sizeof (mbstate_t));
       if (mbrtowc (&wc, "", 1, &state) != 0)
-        return 1;
+        return 2;
     }
   return 0;
 }]])],
@@ -533,11 +563,206 @@ int main ()
     ])
 ])
 
-# Prerequisites of lib/mbrtowc.c.
+dnl Test whether mbrtowc stores a wide character when reporting incomplete
+dnl input.
+
+AC_DEFUN([gl_MBRTOWC_STORES_INCOMPLETE],
+[
+  AC_REQUIRE([AC_PROG_CC])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_CACHE_CHECK([whether mbrtowc stores incomplete characters],
+    [gl_cv_func_mbrtowc_stores_incomplete],
+    [
+     dnl Initial guess, used when cross-compiling or when no suitable locale
+     dnl is present.
+changequote(,)dnl
+     case "$host_os" in
+               # Guess yes on native Windows.
+       mingw*) gl_cv_func_mbrtowc_stores_incomplete="guessing yes" ;;
+       *)      gl_cv_func_mbrtowc_stores_incomplete="guessing no" ;;
+     esac
+changequote([,])dnl
+     case "$host_os" in
+       mingw*)
+         AC_RUN_IFELSE(
+           [AC_LANG_SOURCE([[
+#include <locale.h>
+#include <string.h>
+#include <wchar.h>
+int main ()
+{
+  int result = 0;
+  if (setlocale (LC_ALL, "French_France.65001") != NULL)
+    {
+      wchar_t wc = (wchar_t) 0xBADFACE;
+      mbstate_t state;
+
+      memset (&state, '\0', sizeof (mbstate_t));
+      if (mbrtowc (&wc, "\303", 1, &state) == (size_t)(-2)
+          && wc != (wchar_t) 0xBADFACE)
+        result |= 1;
+    }
+  if (setlocale (LC_ALL, "Japanese_Japan.932") != NULL)
+    {
+      wchar_t wc = (wchar_t) 0xBADFACE;
+      mbstate_t state;
+
+      memset (&state, '\0', sizeof (mbstate_t));
+      if (mbrtowc (&wc, "\226", 1, &state) == (size_t)(-2)
+          && wc != (wchar_t) 0xBADFACE)
+        result |= 2;
+    }
+  if (setlocale (LC_ALL, "Chinese_Taiwan.950") != NULL)
+    {
+      wchar_t wc = (wchar_t) 0xBADFACE;
+      mbstate_t state;
+
+      memset (&state, '\0', sizeof (mbstate_t));
+      if (mbrtowc (&wc, "\245", 1, &state) == (size_t)(-2)
+          && wc != (wchar_t) 0xBADFACE)
+        result |= 4;
+    }
+  if (setlocale (LC_ALL, "Chinese_China.936") != NULL)
+    {
+      wchar_t wc = (wchar_t) 0xBADFACE;
+      mbstate_t state;
+
+      memset (&state, '\0', sizeof (mbstate_t));
+      if (mbrtowc (&wc, "\261", 1, &state) == (size_t)(-2)
+          && wc != (wchar_t) 0xBADFACE)
+        result |= 8;
+    }
+  return result;
+}]])],
+           [gl_cv_func_mbrtowc_stores_incomplete=no],
+           [gl_cv_func_mbrtowc_stores_incomplete=yes],
+           [:])
+         ;;
+       *)
+         AC_REQUIRE([gt_LOCALE_FR_UTF8])
+         if test $LOCALE_FR_UTF8 != none; then
+           AC_RUN_IFELSE(
+             [AC_LANG_SOURCE([[
+#include <locale.h>
+#include <string.h>
+#include <wchar.h>
+int main ()
+{
+  if (setlocale (LC_ALL, "$LOCALE_FR_UTF8") != NULL)
+    {
+      wchar_t wc = (wchar_t) 0xBADFACE;
+      mbstate_t state;
+
+      memset (&state, '\0', sizeof (mbstate_t));
+      if (mbrtowc (&wc, "\303", 1, &state) == (size_t)(-2)
+          && wc != (wchar_t) 0xBADFACE)
+        return 1;
+    }
+  return 0;
+}]])],
+             [gl_cv_func_mbrtowc_stores_incomplete=no],
+             [gl_cv_func_mbrtowc_stores_incomplete=yes],
+             [:])
+         fi
+         ;;
+     esac
+    ])
+])
+
+dnl Test whether mbrtowc returns the correct value on empty input.
+
+AC_DEFUN([gl_MBRTOWC_EMPTY_INPUT],
+[
+  AC_REQUIRE([AC_PROG_CC])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_CACHE_CHECK([whether mbrtowc works on empty input],
+    [gl_cv_func_mbrtowc_empty_input],
+    [
+      dnl Initial guess, used when cross-compiling or when no suitable locale
+      dnl is present.
+changequote(,)dnl
+      case "$host_os" in
+                              # Guess no on AIX and glibc systems.
+        aix* | *-gnu* | gnu*) gl_cv_func_mbrtowc_empty_input="guessing no" ;;
+                              # Guess yes on native Windows.
+        mingw*)               gl_cv_func_mbrtowc_empty_input="guessing yes" ;;
+        *)                    gl_cv_func_mbrtowc_empty_input="guessing yes" ;;
+      esac
+changequote([,])dnl
+      AC_RUN_IFELSE(
+        [AC_LANG_SOURCE([[
+           #include <wchar.h>
+           static wchar_t wc;
+           static mbstate_t mbs;
+           int
+           main (void)
+           {
+             return mbrtowc (&wc, "", 0, &mbs) != (size_t) -2;
+           }]])],
+        [gl_cv_func_mbrtowc_empty_input=yes],
+        [gl_cv_func_mbrtowc_empty_input=no],
+        [:])
+    ])
+])
+
+dnl Test whether mbrtowc reports encoding errors in the C locale.
+dnl Although POSIX was never intended to allow this, the GNU C Library
+dnl and other implementations do it.  See:
+dnl https://sourceware.org/bugzilla/show_bug.cgi?id=19932
+
+AC_DEFUN([gl_MBRTOWC_C_LOCALE],
+[
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_CACHE_CHECK([whether the C locale is free of encoding errors],
+    [gl_cv_func_mbrtowc_C_locale_sans_EILSEQ],
+    [
+     dnl Initial guess, used when cross-compiling or when no suitable locale
+     dnl is present.
+     gl_cv_func_mbrtowc_C_locale_sans_EILSEQ="$gl_cross_guess_normal"
+
+     AC_RUN_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[#include <limits.h>
+            #include <locale.h>
+            #include <wchar.h>
+          ]], [[
+            int i;
+            char *locale = setlocale (LC_ALL, "C");
+            if (! locale)
+              return 2;
+            for (i = CHAR_MIN; i <= CHAR_MAX; i++)
+              {
+                char c = i;
+                wchar_t wc;
+                mbstate_t mbs = { 0, };
+                size_t ss = mbrtowc (&wc, &c, 1, &mbs);
+                if (1 < ss)
+                  return 3;
+              }
+            return 0;
+          ]])],
+      [gl_cv_func_mbrtowc_C_locale_sans_EILSEQ=yes],
+      [gl_cv_func_mbrtowc_C_locale_sans_EILSEQ=no],
+      [case "$host_os" in
+                 # Guess yes on native Windows.
+         mingw*) gl_cv_func_mbrtowc_C_locale_sans_EILSEQ="guessing yes" ;;
+       esac
+      ])
+    ])
+])
+
+# Prerequisites of lib/mbrtowc.c and lib/lc-charset-dispatch.c.
 AC_DEFUN([gl_PREREQ_MBRTOWC], [
+  AC_REQUIRE([AC_C_INLINE])
   :
 ])
 
+# Prerequisites of lib/mbtowc-lock.c.
+AC_DEFUN([gl_PREREQ_MBTOWC_LOCK],
+[
+  gl_VISIBILITY
+])
+
 
 dnl From Paul Eggert
 
@@ -547,24 +772,17 @@ AC_DEFUN([AC_FUNC_MBRTOWC],
 [
   dnl Same as AC_FUNC_MBRTOWC in autoconf-2.60.
   AC_CACHE_CHECK([whether mbrtowc and mbstate_t are properly declared],
-    gl_cv_func_mbrtowc,
+    [gl_cv_func_mbrtowc],
     [AC_LINK_IFELSE(
        [AC_LANG_PROGRAM(
-            [[/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be
-                 included before <wchar.h>.
-                 BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h>
-                 must be included before <wchar.h>.  */
-              #include <stddef.h>
-              #include <stdio.h>
-              #include <time.h>
-              #include <wchar.h>]],
+            [[#include <wchar.h>]],
             [[wchar_t wc;
               char const s[] = "";
               size_t n = 1;
               mbstate_t state;
               return ! (sizeof state && (mbrtowc) (&wc, s, n, &state));]])],
-       gl_cv_func_mbrtowc=yes,
-       gl_cv_func_mbrtowc=no)])
+       [gl_cv_func_mbrtowc=yes],
+       [gl_cv_func_mbrtowc=no])])
   if test $gl_cv_func_mbrtowc = yes; then
     AC_DEFINE([HAVE_MBRTOWC], [1],
       [Define to 1 if mbrtowc and mbstate_t are properly declared.])