Author: Aaron Ballman Date: 2025-04-30T06:55:20-04:00 New Revision: f2b8539803ea5887a9653d26cdcacaabd536ae1c
URL: https://github.com/llvm/llvm-project/commit/f2b8539803ea5887a9653d26cdcacaabd536ae1c DIFF: https://github.com/llvm/llvm-project/commit/f2b8539803ea5887a9653d26cdcacaabd536ae1c.diff LOG: [C2y] Correctly handle 0 in the preprocessor (#137844) We do not diagnose 0 as a deprecated octal literal outside of the preprocessor. This fixes a bug where we were accidentally diagnosing 0 from a preprocessor conditional, however. No release note because this is fixing an issue with a new change. Added: Modified: clang/lib/Lex/LiteralSupport.cpp clang/test/C/C2y/n3353.c Removed: ################################################################################ diff --git a/clang/lib/Lex/LiteralSupport.cpp b/clang/lib/Lex/LiteralSupport.cpp index 20933cc8dee69..75ad977d64b24 100644 --- a/clang/lib/Lex/LiteralSupport.cpp +++ b/clang/lib/Lex/LiteralSupport.cpp @@ -1420,7 +1420,7 @@ void NumericLiteralParser::ParseNumberStartingWithZero(SourceLocation TokLoc) { } // Parse a potential octal literal prefix. - bool SawOctalPrefix = false; + bool SawOctalPrefix = false, IsSingleZero = false; if ((c1 == 'O' || c1 == 'o') && (s[1] >= '0' && s[1] <= '7')) { unsigned DiagId; if (LangOpts.C2y) @@ -1438,7 +1438,8 @@ void NumericLiteralParser::ParseNumberStartingWithZero(SourceLocation TokLoc) { auto _ = llvm::make_scope_exit([&] { // If we still have an octal value but we did not see an octal prefix, // diagnose as being an obsolescent feature starting in C2y. - if (radix == 8 && LangOpts.C2y && !SawOctalPrefix && !hadError) + if (radix == 8 && LangOpts.C2y && !SawOctalPrefix && !hadError && + !IsSingleZero) Diags.Report(TokLoc, diag::warn_unprefixed_octal_deprecated); }); @@ -1453,6 +1454,8 @@ void NumericLiteralParser::ParseNumberStartingWithZero(SourceLocation TokLoc) { // anything, we leave the digit start where it was. if (s != PossibleNewDigitStart) DigitsBegin = PossibleNewDigitStart; + else + IsSingleZero = (s == ThisTokEnd); // Is the only thing we've seen a 0? if (s == ThisTokEnd) return; // Done, simple octal number like 01234 diff --git a/clang/test/C/C2y/n3353.c b/clang/test/C/C2y/n3353.c index fb7f9439ac21b..a616228f1bad0 100644 --- a/clang/test/C/C2y/n3353.c +++ b/clang/test/C/C2y/n3353.c @@ -46,6 +46,10 @@ static const void *ptr = 0o0; /* ext-warning {{octal integer literals are a C2y // 0 by itself is not deprecated, of course. int k = 0; +// Test a preprocessor use of 0 by itself, which is also not deprecated. +#if 0 +#endif + // Make sure there are no surprises with auto and type deduction. Promotion // turns this into an 'int', and 'constexpr' implies 'const'. constexpr auto l = 0o1234567; /* ext-warning {{octal integer literals are a C2y extension}} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
