https://github.com/filaka771 updated https://github.com/llvm/llvm-project/pull/203792
>From ba175808e3dc5b5c4f078c2df3c5d44dcf8c73f8 Mon Sep 17 00:00:00 2001 From: Alex Filak <[email protected]> Date: Sun, 14 Jun 2026 00:40:00 +0300 Subject: [PATCH 1/2] [clang] Fix char-array constant-conversion suppression --- clang/lib/Sema/SemaChecking.cpp | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp index 1c1cd0f2927530..c6df12923c386a 100644 --- a/clang/lib/Sema/SemaChecking.cpp +++ b/clang/lib/Sema/SemaChecking.cpp @@ -12792,7 +12792,8 @@ static void DiagnoseNullConversion(Sema &S, Expr *E, QualType T, } // Helper function to filter out cases for constant width constant conversion. -// Don't warn on char array initialization or for non-decimal values. +// Don't warn on char / unsigned char array initialization or for non-decimal +// values. static bool isSameWidthConstantConversion(Sema &S, Expr *E, QualType T, SourceLocation CC) { // If initializing from a constant, and the constant starts with '0', @@ -12805,12 +12806,16 @@ static bool isSameWidthConstantConversion(Sema &S, Expr *E, QualType T, return false; } - // If the CC location points to a '{', and the type is char, then assume - // assume it is an array initialization. + // If the CC location points to a '{', and the destination type is char or + // unsigned char, then assume this is an array initialization. Keep warning + // for signed char arrays, where values such as 255 change sign. if (CC.isValid() && T->isCharType()) { + const auto *BT = + dyn_cast<BuiltinType>(S.Context.getCanonicalType(T).getTypePtr()); const char FirstContextCharacter = S.getSourceManager().getCharacterData(CC)[0]; - if (FirstContextCharacter == '{') + if (BT && BT->isCharType() && BT->getKind() != BuiltinType::SChar && + FirstContextCharacter == '{') return false; } >From fb1c6b8bfcb91c3a60ba9437b61170fe34589536 Mon Sep 17 00:00:00 2001 From: Alex Filak <[email protected]> Date: Sun, 14 Jun 2026 00:40:12 +0300 Subject: [PATCH 2/2] [clang] Add char-array constant-conversion tests --- clang/test/Sema/constant-conversion.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/clang/test/Sema/constant-conversion.c b/clang/test/Sema/constant-conversion.c index ffc25b9cc49787..b40379e2180ce6 100644 --- a/clang/test/Sema/constant-conversion.c +++ b/clang/test/Sema/constant-conversion.c @@ -125,6 +125,16 @@ void test9(void) { char macro_char_dec = CHAR_MACRO_DEC; // expected-warning {{implicit conversion from 'int' to 'char' changes value from 255 to -1}} char array_init[] = { 255, 127, 128, 129, 0 }; + unsigned char unsigned_array_init[] = { 255 }; + unsigned char unsigned_array_init_multi[] = { 255, 127, 128, 129, 0 }; + signed char signed_array_init[] = { 255 }; // expected-warning {{implicit conversion from 'int' to 'signed char' changes value from 255 to -1}} + signed char signed_array_init_multi[] = { + 255, // expected-warning {{implicit conversion from 'int' to 'signed char' changes value from 255 to -1}} + 127, + 128, // expected-warning {{implicit conversion from 'int' to 'signed char' changes value from 128 to -128}} + 129, // expected-warning {{implicit conversion from 'int' to 'signed char' changes value from 129 to -127}} + 0 + }; } #define A 1 _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
