https://github.com/AhmedKamel10 updated https://github.com/llvm/llvm-project/pull/225597
>From 24f6a72b872a1ee6ef34435e2ffe55cb6661714a Mon Sep 17 00:00:00 2001 From: ahmedkamel10 <[email protected]> Date: Wed, 23 Sep 2026 07:53:34 +0300 Subject: [PATCH 1/2] [Clang] Fix integer promotion of bit-fields in statement expressions --- clang/lib/AST/Expr.cpp | 7 +++++++ clang/test/Sema/stmtexprs.c | 9 +++++++++ 2 files changed, 16 insertions(+) diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp index 6ce0a29aa3bd78..728be799c50a39 100644 --- a/clang/lib/AST/Expr.cpp +++ b/clang/lib/AST/Expr.cpp @@ -4273,6 +4273,13 @@ FieldDecl *Expr::getSourceBitField() { break; } + if (StmtExpr *SE = dyn_cast<StmtExpr>(E)) { + CompoundStmt *CS = SE->getSubStmt(); + if (ValueStmt *VS = dyn_cast_or_null<ValueStmt>(CS->body_back())) + if (Expr *EX = VS->getExprStmt()) + return EX->getSourceBitField(); + } + if (MemberExpr *MemRef = dyn_cast<MemberExpr>(E)) if (FieldDecl *Field = dyn_cast<FieldDecl>(MemRef->getMemberDecl())) if (Field->isBitField()) diff --git a/clang/test/Sema/stmtexprs.c b/clang/test/Sema/stmtexprs.c index 7493bbcef363d9..b5fd9c21226b44 100644 --- a/clang/test/Sema/stmtexprs.c +++ b/clang/test/Sema/stmtexprs.c @@ -7,3 +7,12 @@ void stmtexprs(int i) { // expected-warning@+1 {{assumption is ignored because it contains (potential) side-effects}} __builtin_assume( ({ if (i) ({ stmtexpr_fn(); }); 1; }) ); } + +struct S { + unsigned b : 3; +}; + +void test_bitfield_promotion(struct S s) { + _Static_assert(_Generic(+({ s.b; }), int: 1, unsigned: 2) == 1, + "bit-field in statement expression should be promoted"); +} >From 4b9f66f2e61fafb612f46ea22b52e051a64a3d30 Mon Sep 17 00:00:00 2001 From: ahmedkamel10 <[email protected]> Date: Wed, 23 Sep 2026 17:39:20 +0300 Subject: [PATCH 2/2] Add release note and additional test coverage for bit-field promotion in statement expressions --- clang/docs/ReleaseNotes.md | 5 ++++- clang/test/Sema/stmtexprs.c | 6 ++++++ 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/clang/docs/ReleaseNotes.md b/clang/docs/ReleaseNotes.md index e5da258b9950a3..18003de80b08e1 100644 --- a/clang/docs/ReleaseNotes.md +++ b/clang/docs/ReleaseNotes.md @@ -548,7 +548,10 @@ features cannot lower the translation-unit ABI level; - Fixed an ICE hat occurred when using `__imag int/float` as lvalue in assignment. (#GH119498) - Fixed an assertion failure in `-Wsign-compare` when a negated or complemented vector of unsigned integers was compared against a signed constant. (#GH203575) - Fixed an assertion failure when a constant statement expression that declares a variable is used as a bound of an OpenMP loop. A statement expression in a bound of a non-rectangular loop is now diagnosed. (#GH153987) - +- Fixed a bug where a bit-field accessed as the result of a statement expression + (e.g. `({ s.b; })`) was not subject to integer promotion, unlike an ordinary + bit-field access. (#GH221542) + #### Bug Fixes to Compiler Builtins - Fixed a crash when classifying a call to a builtin with dependent arguments, diff --git a/clang/test/Sema/stmtexprs.c b/clang/test/Sema/stmtexprs.c index b5fd9c21226b44..baddba18445c82 100644 --- a/clang/test/Sema/stmtexprs.c +++ b/clang/test/Sema/stmtexprs.c @@ -15,4 +15,10 @@ struct S { void test_bitfield_promotion(struct S s) { _Static_assert(_Generic(+({ s.b; }), int: 1, unsigned: 2) == 1, "bit-field in statement expression should be promoted"); + _Static_assert(_Generic(+s.b, int: 1, unsigned: 2) == 1, + "ordinary bit-field access should be promoted"); + _Static_assert(_Generic(({ s.b; }), int: 1, unsigned: 2) == 2, + "bit-field in statement expression without unary + should not be promoted"); + _Static_assert(_Generic(s.b, int: 1, unsigned: 2) == 2, + "ordinary bit-field access without unary + should not be promoted"); } _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
