locale.c: Use strerror_l if platform has it

strerror_l makes the my_strerror function trivial, as it doesn't have to
worry about critical sections, etc.  Even on unthreaded perls, it avoids
having to change the current locale, and then change it back.

1 files changed, 26 insertions, 7 deletions

diff --git a/locale.c b/locale.c
index 14dcfe0502..8f5cfd1f39 100644
--- a/locale.c
+++ b/locale.c
@@ -2728,9 +2728,27 @@ Perl_my_strerror(pTHX_ const int errnum)
 
     const bool within_locale_scope = IN_LC(LC_MESSAGES);
 
-#  ifdef USE_POSIX_2008_LOCALE
+#  if defined(HAS_POSIX_2008_LOCALE) && defined(HAS_STRERROR_L)
+
+    /* This function is trivial if we have strerror_l() */
+
+    if (within_locale_scope) {
+        errstr = strerror(errnum);
+    }
+    else {
+        errstr = strerror_l(errnum, PL_C_locale_obj);
+    }
+
+    errstr = savepv(errstr);
+
+#  else /* Doesn't have strerror_l(). */
+
+#    ifdef USE_POSIX_2008_LOCALE
+
     locale_t save_locale = NULL;
-#  else
+
+#    else
+
     char * save_locale = NULL;
     bool locale_is_C = FALSE;
 
@@ -2739,7 +2757,7 @@ Perl_my_strerror(pTHX_ const int errnum)
      * setlocale() ) */
     LOCALE_LOCK;
 
-#  endif
+#    endif
 
     DEBUG_Lv(PerlIO_printf(Perl_debug_log,
                             "my_strerror called with errnum %d\n", errnum));
@@ -2761,7 +2779,7 @@ Perl_my_strerror(pTHX_ const int errnum)
                                     "uselocale returned 0x%p\n", save_locale));
         }
 
-#  else    /* Not thread-safe build */
+#    else    /* Not thread-safe build */
 
         save_locale = setlocale(LC_MESSAGES, NULL);
         if (! save_locale) {
@@ -2781,7 +2799,7 @@ Perl_my_strerror(pTHX_ const int errnum)
             }
         }
 
-#  endif
+#    endif
 
     }   /* end of ! within_locale_scope */
     else {
@@ -2807,7 +2825,7 @@ Perl_my_strerror(pTHX_ const int errnum)
         }
     }
 
-#  else
+#    else
 
         if (save_locale && ! locale_is_C) {
             if (! setlocale(LC_MESSAGES, save_locale)) {
@@ -2820,7 +2838,8 @@ Perl_my_strerror(pTHX_ const int errnum)
 
     LOCALE_UNLOCK;
 
-#  endif
+#    endif
+#  endif /* End of doesn't have strerror_l */
 #endif   /* End of does have locale messages */
 
 #ifdef DEBUGGING