setlocale-null: Make API more useful.

* lib/locale.in.h (setlocale_null_r): Renamed from setlocale_null. All
callers changed.
(setlocale_null): New declaration.
* lib/setlocale_null.c (setlocale_null_androidfix): New function,
extracted from setlocale_null_unlocked.
(setlocale_null_unlocked): Invoke it.
(setlocale_null_r): Renamed from setlocale_null.
(setlocale_null): New function, extracted from setlocale_mtsafe in
setlocale.c.
* lib/setlocale.c: Don't include <errno.h>.
(setlocale_mtsafe): Invoke setlocale_null.
* lib/setlocale-lock.c: Update comments.
* doc/posix-functions/setlocale.texi: Mention both functions.

1 files changed, 146 insertions, 25 deletions

diff --git a/lib/setlocale_null.c b/lib/setlocale_null.c
index 8072a4560e..c20125709a 100644
--- a/lib/setlocale_null.c
+++ b/lib/setlocale_null.c
@@ -55,6 +55,37 @@
 /* Use the system's setlocale() function, not the gnulib override, here.  */
 #undef setlocale
 
+static const char *
+setlocale_null_androidfix (int category)
+{
+  const char *result = setlocale (category, NULL);
+
+#ifdef __ANDROID__
+  if (result == NULL)
+    switch (category)
+      {
+      case LC_CTYPE:
+      case LC_NUMERIC:
+      case LC_TIME:
+      case LC_COLLATE:
+      case LC_MONETARY:
+      case LC_MESSAGES:
+      case LC_ALL:
+      case LC_PAPER:
+      case LC_NAME:
+      case LC_ADDRESS:
+      case LC_TELEPHONE:
+      case LC_MEASUREMENT:
+        result = "C";
+        break;
+      default:
+        break;
+      }
+#endif
+
+  return result;
+}
+
 static int
 setlocale_null_unlocked (int category, char *buf, size_t bufsize)
 {
@@ -105,30 +136,7 @@ setlocale_null_unlocked (int category, char *buf, size_t bufsize)
         }
     }
 #else
-  const char *result = setlocale (category, NULL);
-
-# ifdef __ANDROID__
-  if (result == NULL)
-    switch (category)
-      {
-      case LC_CTYPE:
-      case LC_NUMERIC:
-      case LC_TIME:
-      case LC_COLLATE:
-      case LC_MONETARY:
-      case LC_MESSAGES:
-      case LC_ALL:
-      case LC_PAPER:
-      case LC_NAME:
-      case LC_ADDRESS:
-      case LC_TELEPHONE:
-      case LC_MEASUREMENT:
-        result = "C";
-        break;
-      default:
-        break;
-      }
-# endif
+  const char *result = setlocale_null_androidfix (category);
 
   if (result == NULL)
     {
@@ -257,7 +265,7 @@ setlocale_null_with_lock (int category, char *buf, size_t bufsize)
 #endif
 
 int
-setlocale_null (int category, char *buf, size_t bufsize)
+setlocale_null_r (int category, char *buf, size_t bufsize)
 {
 #if SETLOCALE_NULL_ALL_MTSAFE
 # if SETLOCALE_NULL_ONE_MTSAFE
@@ -287,3 +295,116 @@ setlocale_null (int category, char *buf, size_t bufsize)
 # endif
 #endif
 }
+
+const char *
+setlocale_null (int category)
+{
+#if SETLOCALE_NULL_ALL_MTSAFE && SETLOCALE_NULL_ONE_MTSAFE
+  return setlocale_null_androidfix (category);
+#else
+
+  /* This call must be multithread-safe.  To achieve this without using
+     thread-local storage:
+       1. We use a specific static buffer for each possible CATEGORY
+          argument.  So that different threads can call setlocale_mtsafe
+          with different CATEGORY arguments, without interfering.
+       2. We use a simple strcpy or memcpy to fill this static buffer.
+          Filling it through, for example, strcpy + strcat would not be
+          guaranteed to leave the buffer's contents intact if another thread
+          is currently accessing it.  If necessary, the contents is first
+          assembled in a stack-allocated buffer.  */
+  if (category == LC_ALL)
+    {
+# if SETLOCALE_NULL_ALL_MTSAFE
+      return setlocale_null_androidfix (LC_ALL);
+# else
+      char buf[SETLOCALE_NULL_ALL_MAX];
+      static char resultbuf[SETLOCALE_NULL_ALL_MAX];
+
+      if (setlocale_null_r (LC_ALL, buf, sizeof (buf)))
+        return "C";
+      strcpy (resultbuf, buf);
+      return resultbuf;
+# endif
+    }
+  else
+    {
+# if SETLOCALE_NULL_ONE_MTSAFE
+      return setlocale_null_androidfix (category);
+# else
+      enum
+        {
+          LC_CTYPE_INDEX,
+          LC_NUMERIC_INDEX,
+          LC_TIME_INDEX,
+          LC_COLLATE_INDEX,
+          LC_MONETARY_INDEX,
+          LC_MESSAGES_INDEX,
+#  ifdef LC_PAPER
+          LC_PAPER_INDEX,
+#  endif
+#  ifdef LC_NAME
+          LC_NAME_INDEX,
+#  endif
+#  ifdef LC_ADDRESS
+          LC_ADDRESS_INDEX,
+#  endif
+#  ifdef LC_TELEPHONE
+          LC_TELEPHONE_INDEX,
+#  endif
+#  ifdef LC_MEASUREMENT
+          LC_MEASUREMENT_INDEX,
+#  endif
+#  ifdef LC_IDENTIFICATION
+          LC_IDENTIFICATION_INDEX,
+#  endif
+          LC_INDICES_COUNT
+        }
+        i;
+      char buf[SETLOCALE_NULL_MAX];
+      static char resultbuf[LC_INDICES_COUNT][SETLOCALE_NULL_MAX];
+      int err;
+
+      err = setlocale_null_r (category, buf, sizeof (buf));
+      if (err == EINVAL)
+        return NULL;
+      if (err)
+        return "C";
+
+      switch (category)
+        {
+        case LC_CTYPE:          i = LC_CTYPE_INDEX;          break;
+        case LC_NUMERIC:        i = LC_NUMERIC_INDEX;        break;
+        case LC_TIME:           i = LC_TIME_INDEX;           break;
+        case LC_COLLATE:        i = LC_COLLATE_INDEX;        break;
+        case LC_MONETARY:       i = LC_MONETARY_INDEX;       break;
+        case LC_MESSAGES:       i = LC_MESSAGES_INDEX;       break;
+#  ifdef LC_PAPER
+        case LC_PAPER:          i = LC_PAPER_INDEX;          break;
+#  endif
+#  ifdef LC_NAME
+        case LC_NAME:           i = LC_NAME_INDEX;           break;
+#  endif
+#  ifdef LC_ADDRESS
+        case LC_ADDRESS:        i = LC_ADDRESS_INDEX;        break;
+#  endif
+#  ifdef LC_TELEPHONE
+        case LC_TELEPHONE:      i = LC_TELEPHONE_INDEX;      break;
+#  endif
+#  ifdef LC_MEASUREMENT
+        case LC_MEASUREMENT:    i = LC_MEASUREMENT_INDEX;    break;
+#  endif
+#  ifdef LC_IDENTIFICATION
+        case LC_IDENTIFICATION: i = LC_IDENTIFICATION_INDEX; break;
+#  endif
+        default:
+          /* If you get here, a #ifdef LC_xxx is missing.  */
+          abort ();
+        }
+
+      strcpy (resultbuf[i], buf);
+      return resultbuf[i];
+# endif
+    }
+#endif
+}