[C23] Do not diagnose binary literals as an extension #81658
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
We previously would diagnose them as a GNU extension in C mode, but they are now a feature of C23. This removes the old warning group, -Wgnu-binary-literal, as it no longer makes sense and searching through public repositories shows it is a rarely used option (same for the -Wno form). It also adds the companion compatibility warning which existed for C++ but not for C. Fixes llvm#72017
AaronBallman
added
clang
|
@llvm/pr-subscribers-clang Author: Aaron Ballman (AaronBallman) ChangesWe previously would diagnose them as a GNU extension in C mode, but they are now a feature of C23. This removes the old warning group, -Wgnu-binary-literal, as it no longer makes sense and searching through public repositories shows it is a rarely used option (same for the -Wno form). It also adds the companion compatibility warning which existed for C++ but not for C. Fixes #72017 Full diff: https://github.com/llvm/llvm-project/pull/81658.diff 6 Files Affected:
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index dc2fb3b25e3a54..94ce2923b88c54 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -56,6 +56,10 @@ Clang Frontend Potentially Breaking Changes
``ArrayRef<TemplateArgument>`` reduces AST memory usage by 0.4% when compiling clang, and is
expected to show similar improvements on other workloads.
+- Removed the ``-Wgnu-binary-literal`` diagnostic group. Binary literals are no
+ longer a GNU extension, they're now a C23 extension which is controlled via
+ ``-pedantic`` or ``-Wc23-extensions``.
+
Target OS macros extension
^^^^^^^^^^^^^^^^^^^^^^^^^^
A new Clang extension (see :ref:`here <target_os_detail>`) is enabled for
@@ -113,6 +117,8 @@ C Language Changes
C23 Feature Support
^^^^^^^^^^^^^^^^^^^
+- No longer diagnose use of binary literals as an extension in C23 mode. Fixes
+ `#72017 <https://github.com/llvm/llvm-project/issues/72017>`_.
Non-comprehensive list of changes in this release
-------------------------------------------------
diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td
index 975eca0ad9b642..c783421910331c 100644
--- a/clang/include/clang/Basic/DiagnosticGroups.td
+++ b/clang/include/clang/Basic/DiagnosticGroups.td
@@ -44,10 +44,8 @@ def DeprecatedModuleDotMap : DiagGroup<"deprecated-module-dot-map">;
def FrameworkHdrAtImport : DiagGroup<"atimport-in-framework-header">;
def CXX14BinaryLiteral : DiagGroup<"c++14-binary-literal">;
def CXXPre14CompatBinaryLiteral : DiagGroup<"c++98-c++11-compat-binary-literal">;
-def GNUBinaryLiteral : DiagGroup<"gnu-binary-literal">;
def BinaryLiteral : DiagGroup<"binary-literal", [CXX14BinaryLiteral,
- CXXPre14CompatBinaryLiteral,
- GNUBinaryLiteral]>;
+ CXXPre14CompatBinaryLiteral]>;
def GNUCompoundLiteralInitializer : DiagGroup<"gnu-compound-literal-initializer">;
def SingleBitBitFieldConstantConversion :
DiagGroup<"single-bit-bitfield-constant-conversion">;
@@ -1178,8 +1176,7 @@ def : DiagGroup<"c2x-extensions", [C23]>;
// A warning group for warnings about GCC extensions.
def GNU : DiagGroup<"gnu", [GNUAlignofExpression, GNUAnonymousStruct,
- GNUAutoType,
- GNUBinaryLiteral, GNUCaseRange,
+ GNUAutoType, GNUCaseRange,
GNUComplexInteger, GNUCompoundLiteralInitializer,
GNUConditionalOmittedOperand, GNUDesignator,
GNUEmptyStruct,
diff --git a/clang/include/clang/Basic/DiagnosticLexKinds.td b/clang/include/clang/Basic/DiagnosticLexKinds.td
index 75ca2fa16d3485..1354543612b9fb 100644
--- a/clang/include/clang/Basic/DiagnosticLexKinds.td
+++ b/clang/include/clang/Basic/DiagnosticLexKinds.td
@@ -246,7 +246,10 @@ def warn_cxx17_hex_literal : Warning<
"C++ standards before C++17">,
InGroup<CXXPre17CompatPedantic>, DefaultIgnore;
def ext_binary_literal : Extension<
- "binary integer literals are a GNU extension">, InGroup<GNUBinaryLiteral>;
+ "binary integer literals are a C23 extension">, InGroup<C23>;
+def warn_c23_compat_binary_literal : Warning<
+ "binary integer literals are incompatible with C standards before C23">,
+ InGroup<CPre23Compat>, DefaultIgnore;
def ext_binary_literal_cxx14 : Extension<
"binary integer literals are a C++14 extension">, InGroup<CXX14BinaryLiteral>;
def warn_cxx11_compat_binary_literal : Warning<
diff --git a/clang/lib/Lex/LiteralSupport.cpp b/clang/lib/Lex/LiteralSupport.cpp
index 0a78638f680511..571a984884029d 100644
--- a/clang/lib/Lex/LiteralSupport.cpp
+++ b/clang/lib/Lex/LiteralSupport.cpp
@@ -1358,11 +1358,17 @@ void NumericLiteralParser::ParseNumberStartingWithZero(SourceLocation TokLoc) {
// Handle simple binary numbers 0b01010
if ((c1 == 'b' || c1 == 'B') && (s[1] == '0' || s[1] == '1')) {
- // 0b101010 is a C++1y / GCC extension.
- Diags.Report(TokLoc, LangOpts.CPlusPlus14
- ? diag::warn_cxx11_compat_binary_literal
- : LangOpts.CPlusPlus ? diag::ext_binary_literal_cxx14
- : diag::ext_binary_literal);
+ // 0b101010 is a C++14 and C23 extension.
+ unsigned DiagId;
+ if (LangOpts.CPlusPlus14)
+ DiagId = diag::warn_cxx11_compat_binary_literal;
+ else if (LangOpts.C23)
+ DiagId = diag::warn_c23_compat_binary_literal;
+ else if (LangOpts.CPlusPlus)
+ DiagId = diag::ext_binary_literal_cxx14;
+ else
+ DiagId = diag::ext_binary_literal;
+ Diags.Report(TokLoc, DiagId);
++s;
assert(s < ThisTokEnd && "didn't maximally munch?");
radix = 2;
diff --git a/clang/test/C/C2x/n2549.c b/clang/test/C/C2x/n2549.c
new file mode 100644
index 00000000000000..817338bcdacc39
--- /dev/null
+++ b/clang/test/C/C2x/n2549.c
@@ -0,0 +1,14 @@
+// RUN: %clang_cc1 -verify -std=c23 %s
+// RUN: %clang_cc1 -verify=pedantic -std=c17 -pedantic %s
+// RUN: %clang_cc1 -verify=compat -std=c23 -Wpre-c23-compat %s
+
+// expected-no-diagnostics
+
+/* WG14 N2549: Clang 9
+ * Binary literals
+ */
+
+int i = 0b01; /* pedantic-warning {{binary integer literals are a C23 extension}}
+ compat-warning {{binary integer literals are incompatible with C standards before C23}}
+ */
+
diff --git a/clang/test/Lexer/gnu-flags.c b/clang/test/Lexer/gnu-flags.c
index 6e47547b009d52..384339fc859429 100644
--- a/clang/test/Lexer/gnu-flags.c
+++ b/clang/test/Lexer/gnu-flags.c
@@ -1,15 +1,14 @@
// RUN: %clang_cc1 -fsyntax-only -verify %s -DNONE
-// RUN: %clang_cc1 -fsyntax-only -verify %s -DALL -Wgnu
+// RUN: %clang_cc1 -fsyntax-only -verify %s -DALL -Wgnu
// RUN: %clang_cc1 -fsyntax-only -verify %s -DALL \
// RUN: -Wgnu-zero-variadic-macro-arguments \
-// RUN: -Wgnu-imaginary-constant -Wgnu-binary-literal -Wgnu-zero-line-directive
+// RUN: -Wgnu-imaginary-constant -Wgnu-zero-line-directive
// RUN: %clang_cc1 -fsyntax-only -verify %s -DNONE -Wgnu \
// RUN: -Wno-gnu-zero-variadic-macro-arguments \
-// RUN: -Wno-gnu-imaginary-constant -Wno-gnu-binary-literal -Wno-gnu-zero-line-directive
+// RUN: -Wno-gnu-imaginary-constant -Wno-gnu-zero-line-directive
// Additional disabled tests:
// %clang_cc1 -fsyntax-only -verify %s -DZEROARGS -Wgnu-zero-variadic-macro-arguments
// %clang_cc1 -fsyntax-only -verify %s -DIMAGINARYCONST -Wgnu-imaginary-constant
-// %clang_cc1 -fsyntax-only -verify %s -DBINARYLITERAL -Wgnu-binary-literal
// %clang_cc1 -fsyntax-only -verify %s -DLINE0 -Wgnu-zero-line-directive
#if NONE
@@ -38,13 +37,6 @@ void foo( const char* c )
float _Complex c = 1.if;
-#if ALL || BINARYLITERAL
-// expected-warning@+3 {{binary integer literals are a GNU extension}}
-#endif
-
-int b = 0b0101;
-
-
// This case is handled differently because lit has a bug whereby #line 0 is reported to be on line 4294967295
// http://llvm.org/bugs/show_bug.cgi?id=16952
#if ALL || LINE0
|
llvmbot
added
the
clang:frontend
This helps avoid "unknown warning group" diagnostics even though it doesn't actually control a diagnostic.
That's a good idea, I've done that and updated the release notes accordingly. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
We previously would diagnose them as a GNU extension in C mode, but they are now a feature of C23. The -Wgnu-binary-literal warning group no longer controls any diagnostics as this is no longer a GNU extension. The warning group is retained as a noop to help avoid "unknown warning" diagnostics.
This also adds the companion compatibility warning which existed for C++ but not for C.
Fixes #72017