Add libc++ and libc++abi to third-party.

third_party/libc++/src/support/win32/support.cpp

+// -*- C++ -*-
+//===----------------------- support/win32/support.h ----------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include <cstdarg> // va_start, va_end
+#include <cstddef> // size_t
+#include <cstdlib> // malloc
+#include <cstdio>  // vsprintf, vsnprintf
+#include <cstring> // strcpy, wcsncpy
+#include <cwchar>  // mbstate_t
+
+// Some of these functions aren't standard or if they conform, the name does not.
+
+int asprintf(char **sptr, const char *__restrict format, ...)
+{
+    va_list ap;
+    va_start(ap, format);
+    int result;
+    result = vasprintf(sptr, format, ap);
+    va_end(ap);
+    return result;
+}
+
+// Like sprintf, but when return value >= 0 it returns
+// a pointer to a malloc'd string in *sptr.
+// If return >= 0, use free to delete *sptr.
+int vasprintf( char **sptr, const char *__restrict format, va_list ap )
+{
+    *sptr = NULL;
+    // Query the count required.
+    int count = _vsnprintf( NULL, 0, format, ap );
+    if (count < 0)
+        return count;
+    size_t buffer_size = static_cast<size_t>(count) + 1;
+    char* p = static_cast<char*>(malloc(buffer_size));
+    if ( ! p )
+        return -1;
+    // If we haven't used exactly what was required, something is wrong.
+    // Maybe bug in vsnprintf. Report the error and return.
+    if (_vsnprintf(p, buffer_size, format, ap) != count) {
+        free(p);
+        return -1;
+    }
+    // All good. This is returning memory to the caller not freeing it.
+    *sptr = p;
+    return count;
+}
+
+// Returns >= 0: the number of wide characters found in the 
+// multi byte sequence src (of src_size_bytes), that fit in the buffer dst 
+// (of max_dest_chars elements size). The count returned excludes the
+// null terminator. When dst is NULL, no characters are copied 
+// and no "out" parameters are updated.
+// Returns (size_t) -1: an incomplete sequence encountered.
+// Leaves *src pointing the next character to convert or NULL 
+// if a null character was converted from *src.
+size_t mbsnrtowcs( wchar_t *__restrict dst, const char **__restrict src,
+                   size_t src_size_bytes, size_t max_dest_chars, mbstate_t *__restrict ps )
+{
+    const size_t terminated_sequence = static_cast<size_t>(0);
+    //const size_t invalid_sequence = static_cast<size_t>(-1);
+    const size_t incomplete_sequence = static_cast< size_t>(-2);
+
+    size_t dest_converted = 0;
+    size_t source_converted = 0;
+    size_t source_remaining = src_size_bytes;
+    size_t result = 0;
+    bool have_result = false;
+
+    while ( source_remaining ) {
+        if ( dst && dest_converted >= max_dest_chars )
+            break;
+        // Converts one multi byte character.
+        // if result > 0, it's the size in bytes of that character.
+        // othewise if result is zero it indicates the null character has been found.
+        // otherwise it's an error and errno may be set.
+        size_t char_size = mbrtowc( dst ? dst + dest_converted : NULL, *src + source_converted, source_remaining, ps );
+        // Don't do anything to change errno from here on.
+        if ( char_size > 0 ) {
+            source_remaining -= char_size;
+            source_converted += char_size;
+            ++dest_converted;
+            continue;
+        }
+        result = char_size;
+        have_result = true;
+        break;
+    }
+    if ( dst ) {
+        if ( have_result && result == terminated_sequence )
+            *src = NULL;
+        else
+            *src += source_converted;
+    }
+    if ( have_result && result != terminated_sequence && result != incomplete_sequence )
+        return static_cast<size_t>(-1);
+
+    return dest_converted;
+}
+
+// Converts max_source_chars from the wide character buffer pointer to by *src,
+// into the multi byte character sequence buffer stored at dst which must be
+// dst_size_bytes bytes in size.
+// Returns >= 0: the number of bytes in the sequence sequence 
+// converted frome *src, excluding the null terminator.
+// Returns size_t(-1) if an error occurs, also sets errno.
+// If dst is NULL dst_size_bytes is ignored and no bytes are copied to dst 
+// and no "out" parameters are updated.
+size_t wcsnrtombs( char *__restrict dst, const wchar_t **__restrict src,
+                   size_t max_source_chars, size_t dst_size_bytes, mbstate_t *__restrict ps )
+{
+    //const size_t invalid_sequence = static_cast<size_t>(-1);
+
+    size_t source_converted = 0;
+    size_t dest_converted = 0;
+    size_t dest_remaining = dst_size_bytes;
+    size_t char_size = 0;
+    const errno_t no_error = ( errno_t) 0;
+    errno_t result = ( errno_t ) 0;
+    bool have_result = false;
+    bool terminator_found = false;
+
+    while ( source_converted != max_source_chars ) {
+        if ( ! dest_remaining )
+            break;
+        wchar_t c = (*src)[source_converted];
+        if ( dst )
+            result = wcrtomb_s( &char_size, dst + dest_converted, dest_remaining, c, ps);
+        else
+            result = wcrtomb_s( &char_size, NULL, 0, c, ps);
+        // If result is zero there is no error and char_size contains the 
+        // size of the multi-byte-sequence converted.
+        // Otherwise result indicates an errno type error.
+        if ( result == no_error ) {
+            if ( c == L'\0' ) {
+                terminator_found = true;
+                break;
+            }
+            ++source_converted;
+            if ( dst )
+                dest_remaining -= char_size;
+            dest_converted += char_size;
+            continue;
+        }
+        have_result = true;
+        break;
+    }
+    if ( dst ) {
+        if ( terminator_found )
+            *src = NULL;
+        else
+            *src = *src + source_converted;
+    }
+    if ( have_result && result != no_error ) {
+        errno = result;
+        return static_cast<size_t>(-1);
+    }
+
+    return dest_converted;
+}