Author: Aaron Ballman Date: 2025-03-19T07:49:16-04:00 New Revision: 449cdfacc07bd365d49a637196ce8f8067cf845c
URL: https://github.com/llvm/llvm-project/commit/449cdfacc07bd365d49a637196ce8f8067cf845c DIFF: https://github.com/llvm/llvm-project/commit/449cdfacc07bd365d49a637196ce8f8067cf845c.diff LOG: Suppress pedantic diagnostic for a file not ending in EOL (#131794) WG14 added N3411 to the list of papers which apply to older versions of C in C2y, and WG21 adopted CWG787 as a Defect Report in C++11. So we no longer should be issuing a pedantic diagnostic about a file which does not end with a newline character. We do, however, continue to support -Wnewline-eof as an opt-in diagnostic. Added: clang/test/CXX/drs/cwg787.cpp Modified: clang-tools-extra/clangd/Preamble.cpp clang/docs/ReleaseNotes.rst clang/include/clang/Basic/DiagnosticLexKinds.td clang/lib/Lex/Lexer.cpp clang/test/C/C2y/n3411.c clang/test/Lexer/newline-eof.c Removed: clang/test/Lexer/newline-eof-c++98-compat.cpp ################################################################################ diff --git a/clang-tools-extra/clangd/Preamble.cpp b/clang-tools-extra/clangd/Preamble.cpp index b634981bb46bd..6fab3e2191426 100644 --- a/clang-tools-extra/clangd/Preamble.cpp +++ b/clang-tools-extra/clangd/Preamble.cpp @@ -627,10 +627,8 @@ buildPreamble(PathRef FileName, CompilerInvocation CI, return DiagnosticsEngine::Ignored; switch (Info.getID()) { case diag::warn_no_newline_eof: - case diag::warn_cxx98_compat_no_newline_eof: - case diag::ext_no_newline_eof: // If the preamble doesn't span the whole file, drop the no newline at - // eof warnings. + // eof warning. return Bounds.Size != ContentsBuffer->getBufferSize() ? DiagnosticsEngine::Level::Ignored : DiagLevel; diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 867ce60207b9d..075bcc64b1c59 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -130,8 +130,10 @@ C2y Feature Support that ``_Generic`` selection associations may now have ``void`` type, but it also removes UB with code like ``(void)(void)1;``. - Implemented `WG14 N3411 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3411.pdf>`_ - which allows a source file to not end with a newline character. This is still - reported as a conforming extension in earlier language modes. + which allows a source file to not end with a newline character. Note, + ``-pedantic`` will no longer diagnose this in either C or C++ modes. This + feature was adopted as applying to obsolete versions of C in WG14 and as a + defect report in WG21 (CWG787). - Implemented `WG14 N3353 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3353.htm>_` which adds the new ``0o`` and ``0O`` ocal literal prefixes and deprecates octal literals other than ``0`` which do not start with the new prefix. This diff --git a/clang/include/clang/Basic/DiagnosticLexKinds.td b/clang/include/clang/Basic/DiagnosticLexKinds.td index bdb7e9350b5f7..912b8bd46e194 100644 --- a/clang/include/clang/Basic/DiagnosticLexKinds.td +++ b/clang/include/clang/Basic/DiagnosticLexKinds.td @@ -52,15 +52,9 @@ def ext_multi_line_line_comment : Extension<"multi-line // comment">, def ext_line_comment : Extension< "// comments are not allowed in this language">, InGroup<Comment>; -def ext_no_newline_eof : Extension<"no newline at end of file">, - InGroup<NewlineEOF>; def warn_no_newline_eof : Warning<"no newline at end of file">, InGroup<NewlineEOF>, DefaultIgnore; -def warn_cxx98_compat_no_newline_eof : Warning< - "C++98 requires newline at end of file">, - InGroup<CXX98CompatPedantic>, DefaultIgnore; - def ext_dollar_in_identifier : Extension<"'$' in identifier">, InGroup<DiagGroup<"dollar-in-identifier-extension">>; def ext_charize_microsoft : Extension< diff --git a/clang/lib/Lex/Lexer.cpp b/clang/lib/Lex/Lexer.cpp index 96d5d4f440768..3128627490e28 100644 --- a/clang/lib/Lex/Lexer.cpp +++ b/clang/lib/Lex/Lexer.cpp @@ -3187,28 +3187,12 @@ bool Lexer::LexEndOfFile(Token &Result, const char *CurPtr) { ConditionalStack.pop_back(); } - // C99 5.1.1.2p2: If the file is non-empty and didn't end in a newline, issue - // a pedwarn. - if (CurPtr != BufferStart && (CurPtr[-1] != '\n' && CurPtr[-1] != '\r')) { - DiagnosticsEngine &Diags = PP->getDiagnostics(); - SourceLocation EndLoc = getSourceLocation(BufferEnd); - unsigned DiagID = diag::warn_no_newline_eof; - - if (LangOpts.CPlusPlus11) { - // C++11 [lex.phases] 2.2 p2 - // Prefer the C++98 pedantic compatibility warning over the generic, - // non-extension, user-requested "missing newline at EOF" warning. - if (!Diags.isIgnored(diag::warn_cxx98_compat_no_newline_eof, EndLoc)) - DiagID = diag::warn_cxx98_compat_no_newline_eof; - } else { - // This is conforming in C2y, but is an extension in earlier language - // modes. - if (!LangOpts.C2y) - DiagID = diag::ext_no_newline_eof; - } - - Diag(BufferEnd, DiagID) << FixItHint::CreateInsertion(EndLoc, "\n"); - } + // Before C++11 and C2y, a file not ending with a newline was UB. Both + // standards changed this behavior (as a DR or equivalent), but we still have + // an opt-in diagnostic to warn about it. + if (CurPtr != BufferStart && (CurPtr[-1] != '\n' && CurPtr[-1] != '\r')) + Diag(BufferEnd, diag::warn_no_newline_eof) + << FixItHint::CreateInsertion(getSourceLocation(BufferEnd), "\n"); BufferPtr = CurPtr; diff --git a/clang/test/C/C2y/n3411.c b/clang/test/C/C2y/n3411.c index 934a7c70fa67e..0fea769e30460 100644 --- a/clang/test/C/C2y/n3411.c +++ b/clang/test/C/C2y/n3411.c @@ -1,7 +1,8 @@ // RUN: %clang_cc1 -verify=good -std=c2y -Wall -pedantic %s // RUN: %clang_cc1 -verify -Wnewline-eof -std=c2y -Wall -pedantic %s -// RUN: %clang_cc1 -verify -std=c23 -Wall -pedantic %s +// RUN: %clang_cc1 -verify=good -std=c23 -Wall -pedantic %s // RUN: %clang_cc1 -verify=good -std=c23 %s +// RUN: %clang_cc1 -verify -Wnewline-eof -std=c23 %s /* WG14 N3411: Yes * Slay Some Earthly Demons XII diff --git a/clang/test/CXX/drs/cwg787.cpp b/clang/test/CXX/drs/cwg787.cpp new file mode 100644 index 0000000000000..4b5aeb6487a00 --- /dev/null +++ b/clang/test/CXX/drs/cwg787.cpp @@ -0,0 +1,13 @@ +// RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++98 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors +// RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++11 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors +// RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++14 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors +// RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++17 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors +// RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++20 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors +// RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++23 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors +// RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++2c %s -verify -fexceptions -fcxx-exceptions -pedantic-errors +// expected-no-diagnostics + +// This file intentionally does not end with a newline. CWG787 made this +// well-defined behavior. + +// cwg787: 21 \ No newline at end of file diff --git a/clang/test/Lexer/newline-eof-c++98-compat.cpp b/clang/test/Lexer/newline-eof-c++98-compat.cpp deleted file mode 100644 index 9af0b889537b8..0000000000000 --- a/clang/test/Lexer/newline-eof-c++98-compat.cpp +++ /dev/null @@ -1,5 +0,0 @@ -// RUN: %clang_cc1 -fsyntax-only -Wc++98-compat-pedantic -std=c++11 -verify %s -// RUN: %clang_cc1 -fsyntax-only -Wc++98-compat-pedantic -Wnewline-eof -std=c++11 -verify %s - -// The following line isn't terminated, don't fix it. -void foo() {} // expected-warning{{C++98 requires newline at end of file}} \ No newline at end of file diff --git a/clang/test/Lexer/newline-eof.c b/clang/test/Lexer/newline-eof.c index 9f5033384e16f..22245ac357efc 100644 --- a/clang/test/Lexer/newline-eof.c +++ b/clang/test/Lexer/newline-eof.c @@ -1,11 +1,16 @@ -// RUN: %clang_cc1 -fsyntax-only -Wnewline-eof -verify %s -// RUN: %clang_cc1 -fsyntax-only -pedantic -verify %s -// RUN: %clang_cc1 -fsyntax-only -x c++ -std=c++03 -pedantic -verify %s -// RUN: %clang_cc1 -fsyntax-only -Wnewline-eof %s 2>&1 | FileCheck %s +// Allowing a file to end without a newline was adopted as a Defect Report in +// WG21 (CWG787) and in WG14 (added to the list of changes which apply to +// earlier revisions of C in C2y). So it should not issue a pedantic diagnostic +// in any language mode. -// In C++11 mode, this is allowed, so don't warn in pedantic mode. +// RUN: %clang_cc1 -fsyntax-only -Wnewline-eof -verify %s +// RUN: %clang_cc1 -fsyntax-only -pedantic -verify=good %s +// RUN: %clang_cc1 -fsyntax-only -std=c89 -pedantic -Wno-comment -verify=good %s +// RUN: %clang_cc1 -fsyntax-only -x c++ -std=c++03 -pedantic -verify=good %s // RUN: %clang_cc1 -fsyntax-only -x c++ -std=c++11 -Wnewline-eof -verify %s // RUN: %clang_cc1 -fsyntax-only -x c++ -std=c++11 -Werror -pedantic %s +// RUN: %clang_cc1 -fsyntax-only -Wnewline-eof %s 2>&1 | FileCheck %s +// good-no-diagnostics // Make sure the diagnostic shows up properly at the end of the last line. // CHECK: newline-eof.c:[[@LINE+3]]:67 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
