[Patch] libc++: Add a default rune table

[Ed Schouten]

Hi there,

In an attempt to get libc++ working in a new POSIX-like environment
(to be released to the public early/mid next year), I noticed that
libc++ unconditionally requires that the environment provides a
character class table for ASCII. Though most operating systems provide
such a table (or use such a table internally), there is no standards
requirement that such a table is provided.

The classic_table() function currently prints a message and aborts
when compiled on such a system, whereas it could easily fall back to
an integrated table. Attached is a patch that adds such a table.

URL: http://80386.nl/pub/20141210-libcxx-runetable.txt

Best regards,
-- 
Ed Schouten <ed at 80386.nl>
-------------- next part --------------
Index: src/locale.cpp
===================================================================
--- src/locale.cpp	(revision 223766)
+++ src/locale.cpp	(working copy)
@@ -1038,12 +1056,77 @@
 #elif defined(__ANDROID__)
     return reinterpret_cast<const unsigned char*>(_ctype_) + 1;
 #else
-    // Platform not supported: abort so the person doing the port knows what to
-    // fix
-# warning  ctype<char>::classic_table() is not implemented
-    printf("ctype<char>::classic_table() is not implemented\n");
-    abort();
-    return NULL;
+    // Operating system does not use or provide a rune table. Return a
+    // built-in copy.
+    static const ctype<char>::mask builtin_table[] = {
+        cntrl,                          cntrl,
+        cntrl,                          cntrl,
+        cntrl,                          cntrl,
+        cntrl,                          cntrl,
+        cntrl,                          cntrl | space | blank,
+        cntrl | space,                  cntrl | space,
+        cntrl | space,                  cntrl | space,
+        cntrl,                          cntrl,
+        cntrl,                          cntrl,
+        cntrl,                          cntrl,
+        cntrl,                          cntrl,
+        cntrl,                          cntrl,
+        cntrl,                          cntrl,
+        cntrl,                          cntrl,
+        cntrl,                          cntrl,
+        cntrl,                          cntrl,
+        space | blank | print,          punct | print,
+        punct | print,                  punct | print,
+        punct | print,                  punct | print,
+        punct | print,                  punct | print,
+        punct | print,                  punct | print,
+        punct | print,                  punct | print,
+        punct | print,                  punct | print,
+        punct | print,                  punct | print,
+        digit | print | xdigit,         digit | print | xdigit,
+        digit | print | xdigit,         digit | print | xdigit,
+        digit | print | xdigit,         digit | print | xdigit,
+        digit | print | xdigit,         digit | print | xdigit,
+        digit | print | xdigit,         digit | print | xdigit,
+        punct | print,                  punct | print,
+        punct | print,                  punct | print,
+        punct | print,                  punct | print,
+        punct | print,                  upper | xdigit | print | alpha,
+        upper | xdigit | print | alpha, upper | xdigit | print | alpha,
+        upper | xdigit | print | alpha, upper | xdigit | print | alpha,
+        upper | xdigit | print | alpha, upper | print | alpha,
+        upper | print | alpha,          upper | print | alpha,
+        upper | print | alpha,          upper | print | alpha,
+        upper | print | alpha,          upper | print | alpha,
+        upper | print | alpha,          upper | print | alpha,
+        upper | print | alpha,          upper | print | alpha,
+        upper | print | alpha,          upper | print | alpha,
+        upper | print | alpha,          upper | print | alpha,
+        upper | print | alpha,          upper | print | alpha,
+        upper | print | alpha,          upper | print | alpha,
+        upper | print | alpha,          punct | print,
+        punct | print,                  punct | print,
+        punct | print,                  punct | print,
+        punct | print,                  lower | xdigit | print | alpha,
+        lower | xdigit | print | alpha, lower | xdigit | print | alpha,
+        lower | xdigit | print | alpha, lower | xdigit | print | alpha,
+        lower | xdigit | print | alpha, lower | print | alpha,
+        lower | print | alpha,          lower | print | alpha,
+        lower | print | alpha,          lower | print | alpha,
+        lower | print | alpha,          lower | print | alpha,
+        lower | print | alpha,          lower | print | alpha,
+        lower | print | alpha,          lower | print | alpha,
+        lower | print | alpha,          lower | print | alpha,
+        lower | print | alpha,          lower | print | alpha,
+        lower | print | alpha,          lower | print | alpha,
+        lower | print | alpha,          lower | print | alpha,
+        lower | print | alpha,          punct | print,
+        punct | print,                  punct | print,
+        punct | print,                  cntrl,
+    };
+    static_assert(sizeof(builtin_table) / sizeof(builtin_table[0]) == 128,
+                  "Incorrect table size");
+    return builtin_table;
 #endif
 }