Add support for UCNs for character literals
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@116129 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/LiteralSupport.cpp b/lib/Lex/LiteralSupport.cpp
index 9b7c46f..3b739b3 100644
--- a/lib/Lex/LiteralSupport.cpp
+++ b/lib/Lex/LiteralSupport.cpp
@@ -164,13 +164,10 @@
}
/// ProcessUCNEscape - Read the Universal Character Name, check constraints and
-/// convert the UTF32 to UTF8. This is a subroutine of StringLiteralParser.
-/// When we decide to implement UCN's for character constants and identifiers,
-/// we will likely rework our support for UCN's.
-static void ProcessUCNEscape(const char *&ThisTokBuf, const char *ThisTokEnd,
- char *&ResultBuf, bool &HadError,
+/// return the UTF32.
+static bool ProcessUCNEscape(const char *&ThisTokBuf, const char *ThisTokEnd,
+ uint32_t &UcnVal, unsigned short &UcnLen,
SourceLocation Loc, Preprocessor &PP,
- bool wide,
bool Complain) {
if (!PP.getLangOptions().CPlusPlus && !PP.getLangOptions().C99)
PP.Diag(Loc, diag::warn_ucn_not_valid_in_c89);
@@ -184,27 +181,22 @@
if (ThisTokBuf == ThisTokEnd || !isxdigit(*ThisTokBuf)) {
if (Complain)
PP.Diag(Loc, diag::err_ucn_escape_no_digits);
- HadError = 1;
- return;
+ return false;
}
- typedef uint32_t UTF32;
-
- UTF32 UcnVal = 0;
- unsigned short UcnLen = (ThisTokBuf[-1] == 'u' ? 4 : 8);
+ UcnLen = (ThisTokBuf[-1] == 'u' ? 4 : 8);
unsigned short UcnLenSave = UcnLen;
- for (; ThisTokBuf != ThisTokEnd && UcnLen; ++ThisTokBuf, UcnLen--) {
+ for (; ThisTokBuf != ThisTokEnd && UcnLenSave; ++ThisTokBuf, UcnLenSave--) {
int CharVal = HexDigitValue(ThisTokBuf[0]);
if (CharVal == -1) break;
UcnVal <<= 4;
UcnVal |= CharVal;
}
// If we didn't consume the proper number of digits, there is a problem.
- if (UcnLen) {
+ if (UcnLenSave) {
if (Complain)
PP.Diag(PP.AdvanceToTokenCharacter(Loc, ThisTokBuf-ThisTokBegin),
diag::err_ucn_escape_incomplete);
- HadError = 1;
- return;
+ return false;
}
// Check UCN constraints (C99 6.4.3p2).
if ((UcnVal < 0xa0 &&
@@ -213,13 +205,33 @@
|| (UcnVal > 0x10FFFF)) /* the maximum legal UTF32 value */ {
if (Complain)
PP.Diag(Loc, diag::err_ucn_escape_invalid);
+ return false;
+ }
+ return true;
+}
+
+/// EncodeUCNEscape - Read the Universal Character Name, check constraints and
+/// convert the UTF32 to UTF8 or UTF16. This is a subroutine of
+/// StringLiteralParser. When we decide to implement UCN's for identifiers,
+/// we will likely rework our support for UCN's.
+static void EncodeUCNEscape(const char *&ThisTokBuf, const char *ThisTokEnd,
+ char *&ResultBuf, bool &HadError,
+ SourceLocation Loc, Preprocessor &PP,
+ bool wide,
+ bool Complain) {
+ typedef uint32_t UTF32;
+ UTF32 UcnVal = 0;
+ unsigned short UcnLen = 0;
+ if (!ProcessUCNEscape(ThisTokBuf, ThisTokEnd,
+ UcnVal, UcnLen, Loc, PP, Complain)) {
HadError = 1;
return;
}
+
if (wide) {
- (void)UcnLenSave;
- assert((UcnLenSave == 4 || UcnLenSave == 8) &&
- "ProcessUCNEscape - only ucn length of 4 or 8 supported");
+ (void)UcnLen;
+ assert((UcnLen== 4 || UcnLen== 8) &&
+ "EncodeUCNEscape - only ucn length of 4 or 8 supported");
if (!PP.getLangOptions().ShortWChar) {
// Note: our internal rep of wide char tokens is always little-endian.
@@ -702,11 +714,26 @@
bool Warned = false;
while (begin[0] != '\'') {
uint64_t ResultChar;
+
+ // Is this a Universal Character Name escape?
if (begin[0] != '\\') // If this is a normal character, consume it.
ResultChar = *begin++;
- else // Otherwise, this is an escape character.
- ResultChar = ProcessCharEscape(begin, end, HadError, Loc, IsWide, PP,
- /*Complain=*/true);
+ else { // Otherwise, this is an escape character.
+ // Check for UCN.
+ if (begin[1] == 'u' || begin[1] == 'U') {
+ uint32_t utf32 = 0;
+ unsigned short UcnLen = 0;
+ if (!ProcessUCNEscape(begin, end, utf32, UcnLen,
+ Loc, PP, /*Complain=*/true)) {
+ HadError = 1;
+ }
+ ResultChar = utf32;
+ } else {
+ // Otherwise, this is a non-UCN escape character. Process it.
+ ResultChar = ProcessCharEscape(begin, end, HadError, Loc, IsWide, PP,
+ /*Complain=*/true);
+ }
+ }
// If this is a multi-character constant (e.g. 'abc'), handle it. These are
// implementation defined (C99 6.4.4.4p10).
@@ -746,6 +773,9 @@
// Transfer the value from APInt to uint64_t
Value = LitVal.getZExtValue();
+ if (IsWide && PP.getLangOptions().ShortWChar && Value > 0xFFFF)
+ PP.Diag(Loc, diag::warn_ucn_escape_too_large);
+
// If this is a single narrow character, sign extend it (e.g. '\xFF' is "-1")
// if 'char' is signed for this target (C99 6.4.4.4p10). Note that multiple
// character constants are not sign extended in the this implementation:
@@ -915,9 +945,9 @@
}
// Is this a Universal Character Name escape?
if (ThisTokBuf[1] == 'u' || ThisTokBuf[1] == 'U') {
- ProcessUCNEscape(ThisTokBuf, ThisTokEnd, ResultPtr,
- hadError, StringToks[i].getLocation(), PP, wide,
- Complain);
+ EncodeUCNEscape(ThisTokBuf, ThisTokEnd, ResultPtr,
+ hadError, StringToks[i].getLocation(), PP, wide,
+ Complain);
continue;
}
// Otherwise, this is a non-UCN escape character. Process it.