diff --git a/lib/Lex/LiteralSupport.cpp b/lib/Lex/LiteralSupport.cpp
index b6cc599..91da822 100644
--- a/lib/Lex/LiteralSupport.cpp
+++ b/lib/Lex/LiteralSupport.cpp
@@ -13,6 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Lex/LiteralSupport.h"
+#include "clang/Basic/CharInfo.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Lex/LexDiagnostic.h"
 #include "clang/Lex/Preprocessor.h"
@@ -128,7 +129,7 @@
     break;
   case 'x': { // Hex escape.
     ResultChar = 0;
-    if (ThisTokBuf == ThisTokEnd || !isxdigit(*ThisTokBuf)) {
+    if (ThisTokBuf == ThisTokEnd || !isHexDigit(*ThisTokBuf)) {
       if (Diags)
         Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
              diag::err_hex_escape_no_digits) << "x";
@@ -197,7 +198,7 @@
     if (Diags == 0)
       break;
 
-    if (isgraph(ResultChar))
+    if (isPrintable(ResultChar))
       Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
            diag::ext_unknown_escape)
         << std::string(1, ResultChar);
@@ -224,7 +225,7 @@
   // Skip the '\u' char's.
   ThisTokBuf += 2;
 
-  if (ThisTokBuf == ThisTokEnd || !isxdigit(*ThisTokBuf)) {
+  if (ThisTokBuf == ThisTokEnd || !isHexDigit(*ThisTokBuf)) {
     if (Diags)
       Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf,
            diag::err_hex_escape_no_digits) << StringRef(&ThisTokBuf[-1], 1);
@@ -459,8 +460,7 @@
   // and FP constants (specifically, the 'pp-number' regex), and assumes that
   // the byte at "*end" is both valid and not part of the regex.  Because of
   // this, it doesn't have to check for 'overscan' in various places.
-  assert(!isalnum(*ThisTokEnd) && *ThisTokEnd != '.' && *ThisTokEnd != '_' &&
-         "Lexer didn't maximally munch?");
+  assert(!isPreprocessingNumberBody(*ThisTokEnd) && "didn't maximally munch?");
 
   s = DigitsBegin = ThisTokBegin;
   saw_exponent = false;
@@ -483,7 +483,7 @@
     s = SkipDigits(s);
     if (s == ThisTokEnd) {
       // Done.
-    } else if (isxdigit(*s) && !(*s == 'e' || *s == 'E')) {
+    } else if (isHexDigit(*s) && !(*s == 'e' || *s == 'E')) {
       PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s - ThisTokBegin),
               diag::err_invalid_decimal_digit) << StringRef(s, 1);
       hadError = true;
@@ -635,7 +635,7 @@
   s++;
 
   // Handle a hex number like 0x1234.
-  if ((*s == 'x' || *s == 'X') && (isxdigit(s[1]) || s[1] == '.')) {
+  if ((*s == 'x' || *s == 'X') && (isHexDigit(s[1]) || s[1] == '.')) {
     s++;
     radix = 16;
     DigitsBegin = s;
@@ -694,7 +694,7 @@
     s = SkipBinaryDigits(s);
     if (s == ThisTokEnd) {
       // Done.
-    } else if (isxdigit(*s)) {
+    } else if (isHexDigit(*s)) {
       PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s-ThisTokBegin),
               diag::err_invalid_binary_digit) << StringRef(s, 1);
       hadError = true;
@@ -714,7 +714,7 @@
 
   // If we have some other non-octal digit that *is* a decimal digit, see if
   // this is part of a floating point number like 094.123 or 09e1.
-  if (isdigit(*s)) {
+  if (isDigit(*s)) {
     const char *EndDecimal = SkipDigits(s);
     if (EndDecimal[0] == '.' || EndDecimal[0] == 'e' || EndDecimal[0] == 'E') {
       s = EndDecimal;
@@ -724,7 +724,7 @@
 
   // If we have a hex digit other than 'e' (which denotes a FP exponent) then
   // the code is using an incorrect base.
-  if (isxdigit(*s) && *s != 'e' && *s != 'E') {
+  if (isHexDigit(*s) && *s != 'e' && *s != 'E') {
     PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s-ThisTokBegin),
             diag::err_invalid_octal_digit) << StringRef(s, 1);
     hadError = true;