wxSTD ostream& operator<<(wxSTD ostream& os, const wxCStrData& str)
{
-// FIXME-UTF8: always, not only if wxUSE_UNICODE
-#if wxUSE_UNICODE && !defined(__BORLANDC__)
- return os << (const wchar_t*)str.AsWCharBuf();
+#if wxUSE_UNICODE && !wxUSE_UNICODE_UTF8
+ return os << (const char *)str.AsCharBuf();
#else
- return os << (const char*)str.AsCharBuf();
+ return os << str.AsInternal();
#endif
}
}
#endif
+#if wxUSE_UNICODE && defined(HAVE_WOSTREAM)
+
+wxSTD wostream& operator<<(wxSTD wostream& wos, const wxString& str)
+{
+ return wos << str.wc_str();
+}
+
+wxSTD wostream& operator<<(wxSTD wostream& wos, const wxCStrData& str)
+{
+ return wos << str.AsWChar();
+}
+
+wxSTD wostream& operator<<(wxSTD wostream& wos, const wxWCharBuffer& str)
+{
+ return wos << str.data();
+}
+
+#endif // wxUSE_UNICODE && defined(HAVE_WOSTREAM)
+
#endif // wxUSE_STD_IOSTREAM
// ===========================================================================
}
#endif
-#if wxUSE_UNICODE
+#if wxUSE_UNICODE && !wxUSE_UTF8_LOCALE_ONLY
const char* wxCStrData::AsChar() const
{
+#if wxUSE_UNICODE_UTF8
+ if ( wxLocaleIsUtf8 )
+ return AsInternal();
+#endif
+ // under non-UTF8 locales, we have to convert the internal UTF-8
+ // representation using wxConvLibc and cache the result
+
wxString *str = wxConstCast(m_str, wxString);
// convert the string:
+ //
+ // FIXME-UTF8: we'd like to do the conversion in the existing buffer (if we
+ // have it) but it's unfortunately not obvious to implement
+ // because we don't know how big buffer do we need for the
+ // given string length (in case of multibyte encodings, e.g.
+ // ISO-2022-JP or UTF-8 when internal representation is wchar_t)
+ //
+ // One idea would be to store more than just m_convertedToChar
+ // in wxString: then we could record the length of the string
+ // which was converted the last time and try to reuse the same
+ // buffer if the current length is not greater than it (this
+ // could still fail because string could have been modified in
+ // place but it would work most of the time, so we'd do it and
+ // only allocate the new buffer if in-place conversion returned
+ // an error). We could also store a bit saying if the string
+ // was modified since the last conversion (and update it in all
+ // operation modifying the string, of course) to avoid unneeded
+ // consequential conversions. But both of these ideas require
+ // adding more fields to wxString and require profiling results
+ // to be sure that we really gain enough from them to justify
+ // doing it.
wxCharBuffer buf(str->mb_str());
- // FIXME-UTF8: do the conversion in-place in the existing buffer
+ // if it failed, return empty string and not NULL to avoid crashes in code
+ // written with either wxWidgets 2 wxString or std::string behaviour in
+ // mind: neither of them ever returns NULL and so we shouldn't neither
+ if ( !buf )
+ return "";
+
if ( str->m_convertedToChar &&
strlen(buf) == strlen(str->m_convertedToChar) )
{
// and keep it:
return str->m_convertedToChar + m_offset;
}
-#endif // wxUSE_UNICODE
+#endif // wxUSE_UNICODE && !wxUSE_UTF8_LOCALE_ONLY
#if !wxUSE_UNICODE_WCHAR
const wchar_t* wxCStrData::AsWChar() const
// convert the string:
wxWCharBuffer buf(str->wc_str());
+ // notice that here, unlike above in AsChar(), conversion can't fail as our
+ // internal UTF-8 is always well-formed -- or the string was corrupted and
+ // all bets are off anyhow
+
// FIXME-UTF8: do the conversion in-place in the existing buffer
if ( str->m_convertedToWChar &&
wxWcslen(buf) == wxWcslen(str->m_convertedToWChar) )
wxString::SubstrBufFromMB wxString::ConvertStr(const char *psz, size_t nLength,
const wxMBConv& conv)
{
- // FIXME-UTF8: return as-is without copying under UTF8 locale, return
- // converted string under other locales - needs wxCharBuffer
- // changes
-
// anything to do?
if ( !psz || nLength == 0 )
return SubstrBufFromMB("", 0);
+ // if psz is already in UTF-8, we don't have to do the roundtrip to
+ // wchar_t* and back:
+ if ( conv.IsUTF8() )
+ {
+ // we need to validate the input because UTF8 iterators assume valid
+ // UTF-8 sequence and psz may be invalid:
+ if ( wxStringOperations::IsValidUtf8String(psz, nLength) )
+ {
+ return SubstrBufFromMB(wxCharBuffer::CreateNonOwned(psz), nLength);
+ }
+ // else: do the roundtrip through wchar_t*
+ }
+
if ( nLength == npos )
nLength = wxNO_LEN;
return SubstrBufFromMB("", 0);
// and then to UTF-8:
- SubstrBufFromMB buf(ConvertStr(wcBuf, wcLen, wxConvUTF8));
+ SubstrBufFromMB buf(ConvertStr(wcBuf, wcLen, wxMBConvStrictUTF8()));
// widechar -> UTF-8 conversion isn't supposed to ever fail:
wxASSERT_MSG( buf.data, _T("conversion to UTF-8 failed") );
const wxWCharBuffer wxString::wc_str() const
{
- return wxConvUTF8.cMB2WC(m_impl.c_str(),
- m_impl.length() + 1 /* size, not length */,
- NULL);
+ return wxMBConvStrictUTF8().cMB2WC
+ (
+ m_impl.c_str(),
+ m_impl.length() + 1, // size, not length
+ NULL
+ );
}
const wxCharBuffer wxString::mb_str(const wxMBConv& conv) const
{
- // FIXME-UTF8: optimize the case when conv==wxConvUTF8 or wxConvLibc
- // under UTF8 locale
+ if ( conv.IsUTF8() )
+ return wxCharBuffer::CreateNonOwned(m_impl.c_str());
+
// FIXME-UTF8: use wc_str() here once we have buffers with length
size_t wcLen;
- wxWCharBuffer wcBuf(
- wxConvUTF8.cMB2WC(m_impl.c_str(),
- m_impl.length() + 1 /* size, not length */,
- &wcLen));
+ wxWCharBuffer wcBuf(wxMBConvStrictUTF8().cMB2WC
+ (
+ m_impl.c_str(),
+ m_impl.length() + 1, // size
+ &wcLen
+ ));
if ( !wcLen )
return wxCharBuffer("");
- return conv.cWC2MB(wcBuf, wcLen, NULL);
+ return conv.cWC2MB(wcBuf, wcLen+1, NULL);
}
#else // ANSI
// string comparison
// ---------------------------------------------------------------------------
+bool wxString::IsSameAs(wxUniChar c, bool compareWithCase) const
+{
+ return (length() == 1) && (compareWithCase ? GetChar(0u) == c
+ : wxToupper(GetChar(0u)) == wxToupper(c));
+}
+
#ifdef HAVE_STD_STRING_COMPARE
// NB: Comparison code (both if HAVE_STD_STRING_COMPARE and if not) works with
{
// FIXME-UTF8: use wxUniChar::ToLower/ToUpper once added
- size_t idx = 0;
const_iterator i1 = begin();
const_iterator end1 = end();
const_iterator i2 = s.begin();
const_iterator end2 = s.end();
- for ( ; i1 != end1 && i2 != end2; ++idx, ++i1, ++i2 )
+ for ( ; i1 != end1 && i2 != end2; ++i1, ++i2 )
{
wxUniChar lower1 = (wxChar)wxTolower(*i1);
wxUniChar lower2 = (wxChar)wxTolower(*i2);
#endif
#endif
-wxString wxString::FromAscii(const char *ascii)
+wxString wxString::FromAscii(const char *ascii, size_t len)
{
- if (!ascii)
+ if (!ascii || len == 0)
return wxEmptyString;
- size_t len = strlen( ascii );
wxString res;
- if ( len )
{
- wxStringBuffer buf(res, len);
+ wxStringInternalBuffer buf(res, len);
+ wxStringCharType *dest = buf;
- wchar_t *dest = buf;
-
- for ( ;; )
+ for ( ; len > 0; --len )
{
- if ( (*dest++ = (wchar_t)(unsigned char)*ascii++) == L'\0' )
- break;
+ unsigned char c = (unsigned char)*ascii++;
+ wxASSERT_MSG( c < 0x80,
+ _T("Non-ASCII value passed to FromAscii().") );
+
+ *dest++ = (wchar_t)c;
}
}
return res;
}
-wxString wxString::FromAscii(const char ascii)
+wxString wxString::FromAscii(const char *ascii)
+{
+ return FromAscii(ascii, wxStrlen(ascii));
+}
+
+wxString wxString::FromAscii(char ascii)
{
// What do we do with '\0' ?
- wxString res;
- res += (wchar_t)(unsigned char) ascii;
+ unsigned char c = (unsigned char)ascii;
- return res;
+ wxASSERT_MSG( c < 0x80, _T("Non-ASCII value passed to FromAscii().") );
+
+ // NB: the cast to wchar_t causes interpretation of 'ascii' as Latin1 value
+ return wxString(wxUniChar((wchar_t)c));
}
const wxCharBuffer wxString::ToAscii() const
{
// this will allocate enough space for the terminating NUL too
wxCharBuffer buffer(length());
-
-
char *dest = buffer.data();
- const wchar_t *pwc = c_str();
- for ( ;; )
+ for ( const_iterator i = begin(); i != end(); ++i )
{
- *dest++ = (char)(*pwc > SCHAR_MAX ? wxT('_') : *pwc);
+ wxUniChar c(*i);
+ // FIXME-UTF8: unify substituted char ('_') with wxUniChar ('?')
+ *dest++ = c.IsAscii() ? (char)c : '_';
// the output string can't have embedded NULs anyhow, so we can safely
// stop at first of them even if we do have any
- if ( !*pwc++ )
+ if ( !c )
break;
}
return buffer;
}
-#endif // Unicode
+#endif // wxUSE_UNICODE
// extract string of length nCount starting at nFirst
wxString wxString::Mid(size_t nFirst, size_t nCount) const
// check that the string starts with prefix and return the rest of the string
// in the provided pointer if it is not NULL, otherwise return false
-bool wxString::StartsWith(const wxChar *prefix, wxString *rest) const
+bool wxString::StartsWith(const wxString& prefix, wxString *rest) const
{
- wxASSERT_MSG( prefix, _T("invalid parameter in wxString::StartsWith") );
-
- // first check if the beginning of the string matches the prefix: note
- // that we don't have to check that we don't run out of this string as
- // when we reach the terminating NUL, either prefix string ends too (and
- // then it's ok) or we break out of the loop because there is no match
- const wxChar *p = c_str();
- while ( *prefix )
- {
- if ( *prefix++ != *p++ )
- {
- // no match
- return false;
- }
- }
+ if ( compare(0, prefix.length(), prefix) != 0 )
+ return false;
if ( rest )
{
// put the rest of the string into provided pointer
- *rest = p;
+ rest->assign(*this, prefix.length(), npos);
}
return true;
// check that the string ends with suffix and return the rest of it in the
// provided pointer if it is not NULL, otherwise return false
-bool wxString::EndsWith(const wxChar *suffix, wxString *rest) const
+bool wxString::EndsWith(const wxString& suffix, wxString *rest) const
{
- wxASSERT_MSG( suffix, _T("invalid parameter in wxString::EndssWith") );
-
- int start = length() - wxStrlen(suffix);
+ int start = length() - suffix.length();
if ( start < 0 || compare(start, npos, suffix) != 0 )
return false;
// find last non-space character
reverse_iterator psz = rbegin();
while ( (psz != rend()) && wxSafeIsspace(*psz) )
- psz++;
+ ++psz;
// truncate at trailing space start
erase(psz.base(), end());
// find first non-space character
iterator psz = begin();
while ( (psz != end()) && wxSafeIsspace(*psz) )
- psz++;
+ ++psz;
// fix up data and length
erase(begin(), psz);
// conversion to numbers
// ----------------------------------------------------------------------------
-// the implementation of all the functions below is exactly the same so factor
-// it out
-
-template <typename T, typename F>
-bool wxStringToIntType(const wxChar *start,
- T *val,
- int base,
- F func)
-{
- wxCHECK_MSG( val, false, _T("NULL output pointer") );
- wxASSERT_MSG( !base || (base > 1 && base <= 36), _T("invalid base") );
+// The implementation of all the functions below is exactly the same so factor
+// it out. Note that number extraction works correctly on UTF-8 strings, so
+// we can use wxStringCharType and wx_str() for maximum efficiency.
#ifndef __WXWINCE__
- errno = 0;
+ #define DO_IF_NOT_WINCE(x) x
+#else
+ #define DO_IF_NOT_WINCE(x)
#endif
- wxChar *end;
- *val = (*func)(start, &end, base);
-
- // return true only if scan was stopped by the terminating NUL and if the
- // string was not empty to start with and no under/overflow occurred
- return !*end && (end != start)
-#ifndef __WXWINCE__
- && (errno != ERANGE)
-#endif
- ;
-}
+#define WX_STRING_TO_INT_TYPE(val, base, func) \
+ wxCHECK_MSG( val, false, _T("NULL output pointer") ); \
+ wxASSERT_MSG( !base || (base > 1 && base <= 36), _T("invalid base") ); \
+ \
+ DO_IF_NOT_WINCE( errno = 0; ) \
+ \
+ const wxStringCharType *start = wx_str(); \
+ wxStringCharType *end; \
+ *val = func(start, &end, base); \
+ \
+ /* return true only if scan was stopped by the terminating NUL and */ \
+ /* if the string was not empty to start with and no under/overflow */ \
+ /* occurred: */ \
+ return !*end && (end != start) \
+ DO_IF_NOT_WINCE( && (errno != ERANGE) )
bool wxString::ToLong(long *val, int base) const
{
- return wxStringToIntType((const wxChar*)c_str(), val, base, wxStrtol);
+ WX_STRING_TO_INT_TYPE(val, base, wxStrtol);
}
bool wxString::ToULong(unsigned long *val, int base) const
{
- return wxStringToIntType((const wxChar*)c_str(), val, base, wxStrtoul);
+ WX_STRING_TO_INT_TYPE(val, base, wxStrtoul);
}
bool wxString::ToLongLong(wxLongLong_t *val, int base) const
{
- return wxStringToIntType((const wxChar*)c_str(), val, base, wxStrtoll);
+ WX_STRING_TO_INT_TYPE(val, base, wxStrtoll);
}
bool wxString::ToULongLong(wxULongLong_t *val, int base) const
{
- return wxStringToIntType((const wxChar*)c_str(), val, base, wxStrtoull);
+ WX_STRING_TO_INT_TYPE(val, base, wxStrtoull);
}
bool wxString::ToDouble(double *val) const
// formatted output
// ---------------------------------------------------------------------------
+#if !wxUSE_UTF8_LOCALE_ONLY
/* static */
#ifdef wxNEEDS_WXSTRING_PRINTF_MIXIN
-wxString wxStringPrintfMixinBase::DoFormat(const wxString& format, ...)
+wxString wxStringPrintfMixinBase::DoFormatWchar(const wxChar *format, ...)
#else
-wxString wxString::DoFormat(const wxString& format, ...)
+wxString wxString::DoFormatWchar(const wxChar *format, ...)
#endif
{
va_list argptr;
return s;
}
+#endif // !wxUSE_UTF8_LOCALE_ONLY
+
+#if wxUSE_UNICODE_UTF8
+/* static */
+wxString wxString::DoFormatUtf8(const char *format, ...)
+{
+ va_list argptr;
+ va_start(argptr, format);
+
+ wxString s;
+ s.PrintfV(format, argptr);
+
+ va_end(argptr);
+
+ return s;
+}
+#endif // wxUSE_UNICODE_UTF8
/* static */
wxString wxString::FormatV(const wxString& format, va_list argptr)
return s;
}
+#if !wxUSE_UTF8_LOCALE_ONLY
#ifdef wxNEEDS_WXSTRING_PRINTF_MIXIN
-int wxStringPrintfMixinBase::DoPrintf(const wxString& format, ...)
+int wxStringPrintfMixinBase::DoPrintfWchar(const wxChar *format, ...)
#else
-int wxString::DoPrintf(const wxString& format, ...)
+int wxString::DoPrintfWchar(const wxChar *format, ...)
#endif
{
va_list argptr;
return iLen;
}
+#endif // !wxUSE_UTF8_LOCALE_ONLY
+#if wxUSE_UNICODE_UTF8
+int wxString::DoPrintfUtf8(const char *format, ...)
+{
+ va_list argptr;
+ va_start(argptr, format);
+
+ int iLen = PrintfV(format, argptr);
+
+ va_end(argptr);
+
+ return iLen;
+}
+#endif // wxUSE_UNICODE_UTF8
+
+/*
+ Uses wxVsnprintf and places the result into the this string.
+
+ In ANSI build, wxVsnprintf is effectively vsnprintf but in Unicode build
+ it is vswprintf. Due to a discrepancy between vsnprintf and vswprintf in
+ the ISO C99 (and thus SUSv3) standard the return value for the case of
+ an undersized buffer is inconsistent. For conforming vsnprintf
+ implementations the function must return the number of characters that
+ would have been printed had the buffer been large enough. For conforming
+ vswprintf implementations the function must return a negative number
+ and set errno.
+
+ What vswprintf sets errno to is undefined but Darwin seems to set it to
+ EOVERFLOW. The only expected errno are EILSEQ and EINVAL. Both of
+ those are defined in the standard and backed up by several conformance
+ statements. Note that ENOMEM mentioned in the manual page does not
+ apply to swprintf, only wprintf and fwprintf.
+
+ Official manual page:
+ http://www.opengroup.org/onlinepubs/009695399/functions/swprintf.html
+
+ Some conformance statements (AIX, Solaris):
+ http://www.opengroup.org/csq/view.mhtml?RID=ibm%2FSD1%2F3
+ http://www.theopengroup.org/csq/view.mhtml?norationale=1&noreferences=1&RID=Fujitsu%2FSE2%2F10
+
+ Since EILSEQ and EINVAL are rather common but EOVERFLOW is not and since
+ EILSEQ and EINVAL are specifically defined to mean the error is other than
+ an undersized buffer and no other errno are defined we treat those two
+ as meaning hard errors and everything else gets the old behavior which
+ is to keep looping and increasing buffer size until the function succeeds.
+
+ In practice it's impossible to determine before compilation which behavior
+ may be used. The vswprintf function may have vsnprintf-like behavior or
+ vice-versa. Behavior detected on one release can theoretically change
+ with an updated release. Not to mention that configure testing for it
+ would require the test to be run on the host system, not the build system
+ which makes cross compilation difficult. Therefore, we make no assumptions
+ about behavior and try our best to handle every known case, including the
+ case where wxVsnprintf returns a negative number and fails to set errno.
+
+ There is yet one more non-standard implementation and that is our own.
+ Fortunately, that can be detected at compile-time.
+
+ On top of all that, ISO C99 explicitly defines snprintf to write a null
+ character to the last position of the specified buffer. That would be at
+ at the given buffer size minus 1. It is supposed to do this even if it
+ turns out that the buffer is sized too small.
+
+ Darwin (tested on 10.5) follows the C99 behavior exactly.
+
+ Glibc 2.6 almost follows the C99 behavior except vswprintf never sets
+ errno even when it fails. However, it only seems to ever fail due
+ to an undersized buffer.
+*/
#if wxUSE_UNICODE_UTF8
template<typename BufferType>
#else
if ( !buf )
{
// out of memory
+
+ // in UTF-8 build, leaving uninitialized junk in the buffer
+ // could result in invalid non-empty UTF-8 string, so just
+ // reset the string to empty on failure:
+ buf[0] = '\0';
return -1;
}
// only a copy
va_list argptrcopy;
wxVaCopy(argptrcopy, argptr);
+
+#ifndef __WXWINCE__
+ // Set errno to 0 to make it determinate if wxVsnprintf fails to set it.
+ errno = 0;
+#endif
int len = wxVsnprintf(buf, size, format, argptrcopy);
va_end(argptrcopy);
// some implementations of vsnprintf() don't NUL terminate
// the string if there is not enough space for it so
// always do it manually
+ // FIXME: This really seems to be the wrong and would be an off-by-one
+ // bug except the code above allocates an extra character.
buf[size] = _T('\0');
// vsnprintf() may return either -1 (traditional Unix behaviour) or the
// buffer were large enough (newer standards such as Unix98)
if ( len < 0 )
{
+ // NB: wxVsnprintf() may call either wxCRT_VsnprintfW or
+ // wxCRT_VsnprintfA in UTF-8 build; wxUSE_WXVSNPRINTF
+ // is true if *both* of them use our own implementation,
+ // otherwise we can't be sure
#if wxUSE_WXVSNPRINTF
// we know that our own implementation of wxVsnprintf() returns -1
// only for a format error - thus there's something wrong with
// the user's format string
+ buf[0] = '\0';
return -1;
-#else // assume that system version only returns error if not enough space
+#else // possibly using system version
+ // assume it only returns error if there is not enough space, but
+ // as we don't know how much we need, double the current size of
+ // the buffer
+#ifndef __WXWINCE__
+ if( (errno == EILSEQ) || (errno == EINVAL) )
+ // If errno was set to one of the two well-known hard errors
+ // then fail immediately to avoid an infinite loop.
+ return -1;
+ else
+#endif // __WXWINCE__
// still not enough, as we don't know how much we need, double the
// current size of the buffer
- size *= 2;
+ size *= 2;
#endif // wxUSE_WXVSNPRINTF/!wxUSE_WXVSNPRINTF
}
else if ( len >= size )
#else
// some vsnprintf() implementations NUL-terminate the buffer and
// some don't in len == size case, to be safe always add 1
+ // FIXME: I don't quite understand this comment. The vsnprintf
+ // function is specifically defined to return the number of
+ // characters printed not including the null terminator.
+ // So OF COURSE you need to add 1 to get the right buffer size.
+ // The following line is definitely correct, no question.
size = len + 1;
#endif
}
int wxString::PrintfV(const wxString& format, va_list argptr)
{
- va_list argcopy;
- wxVaCopy(argcopy, argptr);
-
#if wxUSE_UNICODE_UTF8
#if wxUSE_STL_BASED_WXSTRING
typedef wxStringTypeBuffer<char> Utf8Buffer;
#else
- typedef wxImplStringBuffer Utf8Buffer;
+ typedef wxStringInternalBuffer Utf8Buffer;
#endif
#endif
#if wxUSE_UTF8_LOCALE_ONLY
- return DoStringPrintfV<Utf8Buffer>(*this, format, argcopy);
+ return DoStringPrintfV<Utf8Buffer>(*this, format, argptr);
#else
#if wxUSE_UNICODE_UTF8
if ( wxLocaleIsUtf8 )
- return DoStringPrintfV<Utf8Buffer>(*this, format, argcopy);
+ return DoStringPrintfV<Utf8Buffer>(*this, format, argptr);
else
// wxChar* version
- return DoStringPrintfV<wxStringBuffer>(*this, format, argcopy);
+ return DoStringPrintfV<wxStringBuffer>(*this, format, argptr);
#else
- return DoStringPrintfV(*this, format, argcopy);
+ return DoStringPrintfV(*this, format, argptr);
#endif // UTF8/WCHAR
#endif
}
// convert to lower case, return the copy of the string
wxString wxString::Lower() const { wxString s(*this); return s.MakeLower(); }
+
+// ----------------------------------------------------------------------------
+// wxUTF8StringBuffer
+// ----------------------------------------------------------------------------
+
+#if wxUSE_UNICODE_WCHAR
+wxUTF8StringBuffer::~wxUTF8StringBuffer()
+{
+ wxMBConvStrictUTF8 conv;
+ size_t wlen = conv.ToWChar(NULL, 0, m_buf);
+ wxCHECK_RET( wlen != wxCONV_FAILED, "invalid UTF-8 data in string buffer?" );
+
+ wxStringInternalBuffer wbuf(m_str, wlen);
+ conv.ToWChar(wbuf, wlen, m_buf);
+}
+
+wxUTF8StringBufferLength::~wxUTF8StringBufferLength()
+{
+ wxCHECK_RET(m_lenSet, "length not set");
+
+ wxMBConvStrictUTF8 conv;
+ size_t wlen = conv.ToWChar(NULL, 0, m_buf, m_len);
+ wxCHECK_RET( wlen != wxCONV_FAILED, "invalid UTF-8 data in string buffer?" );
+
+ wxStringInternalBufferLength wbuf(m_str, wlen);
+ conv.ToWChar(wbuf, wlen, m_buf, m_len);
+ wbuf.SetLength(wlen);
+}
+#endif // wxUSE_UNICODE_WCHAR
projects / wxWidgets.git / blobdiff