When checking the encoding of an 8-bit string literal, don't just check the

first codepoint! Also, don't reject empty raw string literals for spurious
"encoding" issues. Also, don't rely on undefined behavior in ConvertUTF.c.

llvm-svn: 152344

2 files changed, 27 insertions, 16 deletions

diff --git a/clang/lib/Basic/ConvertUTF.c b/clang/lib/Basic/ConvertUTF.c
index b3fa9169344..e1970039e16 100644
--- a/clang/lib/Basic/ConvertUTF.c
+++ b/clang/lib/Basic/ConvertUTF.c
@@ -387,7 +387,7 @@ static Boolean isLegalUTF8(const UTF8 *source, int length) {
  */
 Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd) {
     int length = trailingBytesForUTF8[*source]+1;
-    if (source+length > sourceEnd) {
+    if (length > sourceEnd - source) {
         return false;
     }
     return isLegalUTF8(source, length);
@@ -395,6 +395,22 @@ Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd) {
 
 /* --------------------------------------------------------------------- */
 
+/*
+ * Exported function to return whether a UTF-8 string is legal or not.
+ * This is not used here; it's just exported.
+ */
+Boolean isLegalUTF8String(const UTF8 *source, const UTF8 *sourceEnd) {
+    while (source != sourceEnd) {
+        int length = trailingBytesForUTF8[*source] + 1;
+        if (length > sourceEnd - source || !isLegalUTF8(source, length))
+            return false;
+        source += length;
+    }
+    return true;
+}
+
+/* --------------------------------------------------------------------- */
+
 ConversionResult ConvertUTF8toUTF16 (
         const UTF8** sourceStart, const UTF8* sourceEnd, 
         UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags) {
@@ -404,7 +420,7 @@ ConversionResult ConvertUTF8toUTF16 (
     while (source < sourceEnd) {
         UTF32 ch = 0;
         unsigned short extraBytesToRead = trailingBytesForUTF8[*source];
-        if (source + extraBytesToRead >= sourceEnd) {
+        if (extraBytesToRead >= sourceEnd - source) {
             result = sourceExhausted; break;
         }
         /* Do this check whether lenient or strict */
@@ -477,7 +493,7 @@ ConversionResult ConvertUTF8toUTF32 (
     while (source < sourceEnd) {
         UTF32 ch = 0;
         unsigned short extraBytesToRead = trailingBytesForUTF8[*source];
-        if (source + extraBytesToRead >= sourceEnd) {
+        if (extraBytesToRead >= sourceEnd - source) {
             result = sourceExhausted; break;
         }
         /* Do this check whether lenient or strict */
diff --git a/clang/lib/Lex/LiteralSupport.cpp b/clang/lib/Lex/LiteralSupport.cpp
index 901d96d21ae..e0a5ba39d0f 100644
--- a/clang/lib/Lex/LiteralSupport.cpp
+++ b/clang/lib/Lex/LiteralSupport.cpp
@@ -333,7 +333,7 @@ static void EncodeUCNEscape(const char *&ThisTokBuf, const char *ThisTokEnd,
 ///         decimal-constant integer-suffix
 ///         octal-constant integer-suffix
 ///         hexadecimal-constant integer-suffix
-///       user-defiend-integer-literal: [C++11 lex.ext]
+///       user-defined-integer-literal: [C++11 lex.ext]
 ///         decimal-literal ud-suffix
 ///         octal-literal ud-suffix
 ///         hexadecimal-literal ud-suffix
@@ -1167,17 +1167,14 @@ void StringLiteralParser::init(const Token *StringToks, unsigned NumStringToks){
         ++ThisTokBuf;
       ++ThisTokBuf; // skip '('
 
-      // remove same number of characters from the end
-      if (ThisTokEnd >= ThisTokBuf + (ThisTokBuf - Prefix))
-        ThisTokEnd -= (ThisTokBuf - Prefix);
+      // Remove same number of characters from the end
+      ThisTokEnd -= ThisTokBuf - Prefix;
+      assert(ThisTokEnd >= ThisTokBuf && "malformed raw string literal");
 
       // Copy the string over
-      if (CopyStringFragment(StringRef(ThisTokBuf,ThisTokEnd-ThisTokBuf)))
-      {
+      if (CopyStringFragment(StringRef(ThisTokBuf, ThisTokEnd - ThisTokBuf)))
         if (DiagnoseBadString(StringToks[i]))
           hadError = true;
-      }
-
     } else {
       assert(ThisTokBuf[0] == '"' && "Expected quote, lexer broken?");
       ++ThisTokBuf; // skip "
@@ -1204,11 +1201,9 @@ void StringLiteralParser::init(const Token *StringToks, unsigned NumStringToks){
           } while (ThisTokBuf != ThisTokEnd && ThisTokBuf[0] != '\\');
 
           // Copy the character span over.
-          if (CopyStringFragment(StringRef(InStart,ThisTokBuf-InStart)))
-          {
+          if (CopyStringFragment(StringRef(InStart, ThisTokBuf - InStart)))
             if (DiagnoseBadString(StringToks[i]))
               hadError = true;
-          }
           continue;
         }
         // Is this a Universal Character Name escape?
@@ -1292,8 +1287,8 @@ bool StringLiteralParser::CopyStringFragment(StringRef Fragment) {
   ConversionResult result = conversionOK;
   // Copy the character span over.
   if (CharByteWidth == 1) {
-    if (!isLegalUTF8Sequence(reinterpret_cast<const UTF8*>(Fragment.begin()),
-                             reinterpret_cast<const UTF8*>(Fragment.end())))
+    if (!isLegalUTF8String(reinterpret_cast<const UTF8*>(Fragment.begin()),
+                           reinterpret_cast<const UTF8*>(Fragment.end())))
       result = sourceIllegal;
     memcpy(ResultPtr, Fragment.data(), Fragment.size());
     ResultPtr += Fragment.size();