https://github.com/Andres-Salamanca created https://github.com/llvm/llvm-project/pull/151741
This PR fixes the outdated logic for accumulating bitfields in `accumulateFields`. The old approach remained after the algorithm was updated. A non-bitfield member would act as a barrier, causing `accumulateBitFields` to receive an incomplete range of fields. As a result, it failed to accumulate them properly when clipping was necessary. For reference, in ClangIR we already handle this correctly: [https://github.com/llvm/clangir/blob/b647f4b97b1f936fd7700ec0fd0d896a12fe581b/clang/lib/CIR/CodeGen/CIRRecordLayoutBuilder.cpp#L711-L714](https://github.com/llvm/clangir/blob/b647f4b97b1f936fd7700ec0fd0d896a12fe581b/clang/lib/CIR/CodeGen/CIRRecordLayoutBuilder.cpp#L711-L714) >From 704cd98634dc64fb09538fa1b2bc69c3971627ca Mon Sep 17 00:00:00 2001 From: Andres Salamanca <andrealebarbari...@gmail.com> Date: Fri, 1 Aug 2025 12:44:53 -0500 Subject: [PATCH] [CIR] Fix outdated bitfield iteration logic in accumulateFields --- clang/lib/CIR/CodeGen/CIRGenRecordLayoutBuilder.cpp | 6 +----- clang/test/CIR/CodeGen/bitfields.c | 11 +++++++++++ 2 files changed, 12 insertions(+), 5 deletions(-) diff --git a/clang/lib/CIR/CodeGen/CIRGenRecordLayoutBuilder.cpp b/clang/lib/CIR/CodeGen/CIRGenRecordLayoutBuilder.cpp index 0c8ff4bd807ad..ff9b38f79902c 100644 --- a/clang/lib/CIR/CodeGen/CIRGenRecordLayoutBuilder.cpp +++ b/clang/lib/CIR/CodeGen/CIRGenRecordLayoutBuilder.cpp @@ -499,11 +499,7 @@ void CIRRecordLowering::accumulateFields() { fieldEnd = recordDecl->field_end(); field != fieldEnd;) { if (field->isBitField()) { - RecordDecl::field_iterator start = field; - // Iterate to gather the list of bitfields. - for (++field; field != fieldEnd && field->isBitField(); ++field) - ; - field = accumulateBitFields(start, field); + field = accumulateBitFields(field, fieldEnd); assert((field == fieldEnd || !field->isBitField()) && "Failed to accumulate all the bitfields"); } else if (!field->isZeroSize(astContext)) { diff --git a/clang/test/CIR/CodeGen/bitfields.c b/clang/test/CIR/CodeGen/bitfields.c index 869a7c98e2569..b2c7d1c0be926 100644 --- a/clang/test/CIR/CodeGen/bitfields.c +++ b/clang/test/CIR/CodeGen/bitfields.c @@ -71,12 +71,23 @@ typedef struct { // LLVM-DAG: %struct.U = type <{ i8, i8, i8, i8, i64 }> // OGCG-DAG: %struct.U = type <{ i8, i8, i8, i8, i64 }> +typedef struct{ + int a : 24; + char b; + int c: 30; +} Clip; + +// CIR-DAG: !rec_Clip = !cir.record<struct "Clip" {!cir.array<!u8i x 3>, !s8i, !u32i}> +// LLVM-DAG: %struct.Clip = type { [3 x i8], i8, i32 } +// OGCG-DAG: %struct.Clip = type { [3 x i8], i8, i32 } + void def() { A a; D d; S s; T t; U u; + Clip c; } int load_field(S* s) { _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
