https://github.com/AhmedKamel10 created https://github.com/llvm/llvm-project/pull/225597
Fixes integer promotion for bit-fields used in statement expressions (#221542). `Expr::getSourceBitField()` now looks through the final expression of a statement expression to preserve the bit-field information. This allows the existing integer promotion rules to correctly promote the bit-field to `int`. Also added a regression test for the issue. >From 24f6a72b872a1ee6ef34435e2ffe55cb6661714a Mon Sep 17 00:00:00 2001 From: ahmedkamel10 <[email protected]> Date: Wed, 23 Sep 2026 07:53:34 +0300 Subject: [PATCH] [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"); +} _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
