[clang] 33ec653 - [clang][lexer] Allow u8 character literal prefixes in C2x
Timm Bäder via cfe-commits
cfe-commits at lists.llvm.org
Tue Apr 19 00:59:58 PDT 2022
Author: Timm Bäder
Date: 2022-04-19T09:57:51+02:00
New Revision: 33ec65305525626d5d93bd794c1c9cfa55d0ca8f
URL: https://github.com/llvm/llvm-project/commit/33ec65305525626d5d93bd794c1c9cfa55d0ca8f
DIFF: https://github.com/llvm/llvm-project/commit/33ec65305525626d5d93bd794c1c9cfa55d0ca8f.diff
LOG: [clang][lexer] Allow u8 character literal prefixes in C2x
Implement N2418 for C2x.
Differential Revision: https://reviews.llvm.org/D119221
Added:
Modified:
clang/docs/ReleaseNotes.rst
clang/lib/Lex/Lexer.cpp
clang/lib/Sema/SemaExpr.cpp
clang/test/Lexer/utf8-char-literal.cpp
clang/www/c_status.html
Removed:
################################################################################
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index fd4eac5458c0a..c396322f2de57 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -226,6 +226,7 @@ C2x Feature Support
- Implemented `WG14 N2775 Literal suffixes for bit-precise integers <http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2775.pdf>`_.
- Implemented the `*_WIDTH` macros to complete support for
`WG14 N2412 Two's complement sign representation for C2x <https://www9.open-std.org/jtc1/sc22/wg14/www/docs/n2412.pdf>`_.
+- Implemented `WG14 N2418 Adding the u8 character prefix <http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2418.pdf>`_.
C++ Language Changes in Clang
-----------------------------
diff --git a/clang/lib/Lex/Lexer.cpp b/clang/lib/Lex/Lexer.cpp
index 6e8072fb1b2d9..6fc78cfa8ad95 100644
--- a/clang/lib/Lex/Lexer.cpp
+++ b/clang/lib/Lex/Lexer.cpp
@@ -3459,7 +3459,10 @@ bool Lexer::LexTokenInternal(Token &Result, bool TokAtPhysicalStartOfLine) {
MIOpt.ReadToken();
return LexNumericConstant(Result, CurPtr);
- case 'u': // Identifier (uber) or C11/C++11 UTF-8 or UTF-16 string literal
+ // Identifier (e.g., uber), or
+ // UTF-8 (C2x/C++17) or UTF-16 (C11/C++11) character literal, or
+ // UTF-8 or UTF-16 string literal (C11/C++11).
+ case 'u':
// Notify MIOpt that we read a non-whitespace/non-comment token.
MIOpt.ReadToken();
@@ -3493,7 +3496,7 @@ bool Lexer::LexTokenInternal(Token &Result, bool TokAtPhysicalStartOfLine) {
ConsumeChar(ConsumeChar(CurPtr, SizeTmp, Result),
SizeTmp2, Result),
tok::utf8_string_literal);
- if (Char2 == '\'' && LangOpts.CPlusPlus17)
+ if (Char2 == '\'' && (LangOpts.CPlusPlus17 || LangOpts.C2x))
return LexCharConstant(
Result, ConsumeChar(ConsumeChar(CurPtr, SizeTmp, Result),
SizeTmp2, Result),
@@ -3517,7 +3520,7 @@ bool Lexer::LexTokenInternal(Token &Result, bool TokAtPhysicalStartOfLine) {
// treat u like the start of an identifier.
return LexIdentifierContinue(Result, CurPtr);
- case 'U': // Identifier (Uber) or C11/C++11 UTF-32 string literal
+ case 'U': // Identifier (e.g. Uber) or C11/C++11 UTF-32 string literal
// Notify MIOpt that we read a non-whitespace/non-comment token.
MIOpt.ReadToken();
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 3e84961a5079f..bb0bde6a31b50 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -3609,6 +3609,8 @@ ExprResult Sema::ActOnCharacterConstant(const Token &Tok, Scope *UDLScope) {
QualType Ty;
if (Literal.isWide())
Ty = Context.WideCharTy; // L'x' -> wchar_t in C and C++.
+ else if (Literal.isUTF8() && getLangOpts().C2x)
+ Ty = Context.UnsignedCharTy; // u8'x' -> unsigned char in C2x
else if (Literal.isUTF8() && getLangOpts().Char8)
Ty = Context.Char8Ty; // u8'x' -> char8_t when it exists.
else if (Literal.isUTF16())
@@ -3618,7 +3620,8 @@ ExprResult Sema::ActOnCharacterConstant(const Token &Tok, Scope *UDLScope) {
else if (!getLangOpts().CPlusPlus || Literal.isMultiChar())
Ty = Context.IntTy; // 'x' -> int in C, 'wxyz' -> int in C++.
else
- Ty = Context.CharTy; // 'x' -> char in C++
+ Ty = Context.CharTy; // 'x' -> char in C++;
+ // u8'x' -> char in C11-C17 and in C++ without char8_t.
CharacterLiteral::CharacterKind Kind = CharacterLiteral::Ascii;
if (Literal.isWide())
diff --git a/clang/test/Lexer/utf8-char-literal.cpp b/clang/test/Lexer/utf8-char-literal.cpp
index 0ddaabc842257..ababc8b9c21bc 100644
--- a/clang/test/Lexer/utf8-char-literal.cpp
+++ b/clang/test/Lexer/utf8-char-literal.cpp
@@ -1,5 +1,6 @@
// RUN: %clang_cc1 -triple x86_64-apple-darwin -std=c++11 -fsyntax-only -verify %s
// RUN: %clang_cc1 -triple x86_64-apple-darwin -std=c11 -x c -fsyntax-only -verify %s
+// RUN: %clang_cc1 -triple x86_64-apple-darwin -std=c2x -x c -fsyntax-only -verify %s
// RUN: %clang_cc1 -triple x86_64-apple-darwin -std=c++1z -fsyntax-only -verify %s
int array0[u'ñ' == u'\xf1'? 1 : -1];
@@ -12,4 +13,16 @@ char c = u8'\u0080'; // expected-error {{character too large for enclosing chara
char d = u8'\u1234'; // expected-error {{character too large for enclosing character literal type}}
char e = u8'ሴ'; // expected-error {{character too large for enclosing character literal type}}
char f = u8'ab'; // expected-error {{Unicode character literals may not contain multiple characters}}
+#elif __STDC_VERSION__ > 202000L
+char a = u8'ñ'; // expected-error {{character too large for enclosing character literal type}}
+char b = u8'\x80'; // ok
+char c = u8'\u0080'; // expected-error {{universal character name refers to a control character}}
+char d = u8'\u1234'; // expected-error {{character too large for enclosing character literal type}}
+char e = u8'ሴ'; // expected-error {{character too large for enclosing character literal type}}
+char f = u8'ab'; // expected-error {{Unicode character literals may not contain multiple characters}}
+_Static_assert(
+ _Generic(u8'a',
+ default : 0,
+ unsigned char : 1),
+ "Surprise!");
#endif
diff --git a/clang/www/c_status.html b/clang/www/c_status.html
index 3a00648000e3f..b827d8d1288a9 100644
--- a/clang/www/c_status.html
+++ b/clang/www/c_status.html
@@ -720,7 +720,7 @@ <h2 id="c2x">C2x implementation status</h2>
<tr>
<td>Adding the u8 character prefix</td>
<td><a href="http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2418.pdf">N2418</a></td>
- <td class="none" align="center">No</td>
+ <td class="unreleased" align="center">Clang 15</td>
</tr>
<tr>
<td>Remove support for function definitions with identifier lists</td>
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