[clang] [CIR] Implement VisitCXXStdInitializerListExpr for 2 ptr layout (PR #186679)
Amr Hesham via cfe-commits
cfe-commits at lists.llvm.org
Sun Mar 15 09:20:06 PDT 2026
https://github.com/AmrDeveloper created https://github.com/llvm/llvm-project/pull/186679
Implement support for CXXStdInitializerListExpr for two pointers (begin, end) layout
>From d6f0b970f1509ccbbc72d44d0a59724c942d91f2 Mon Sep 17 00:00:00 2001
From: Amr Hesham <amr96 at programmer.net>
Date: Sun, 15 Mar 2026 17:05:17 +0100
Subject: [PATCH] [CIR] Implement VisitCXXStdInitializerListExpr for 2 ptr
layout
---
clang/lib/CIR/CodeGen/CIRGenExprAggregate.cpp | 16 ++--
.../CodeGen/initializer-list-two-pointers.cpp | 73 +++++++++++++++++++
2 files changed, 83 insertions(+), 6 deletions(-)
create mode 100644 clang/test/CIR/CodeGen/initializer-list-two-pointers.cpp
diff --git a/clang/lib/CIR/CodeGen/CIRGenExprAggregate.cpp b/clang/lib/CIR/CodeGen/CIRGenExprAggregate.cpp
index 9f390fec97613..715af1fb66500 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExprAggregate.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExprAggregate.cpp
@@ -395,6 +395,9 @@ class AggExprEmitter : public StmtVisitor<AggExprEmitter> {
assert(arrayType && "std::initializer_list constructed from non-array");
auto *record = e->getType()->castAsRecordDecl();
+ assert(record->getNumFields() == 2 &&
+ "Expected std::initializer_list to only have two fields");
+
RecordDecl::field_iterator field = record->field_begin();
assert(field != record->field_end() &&
ctx.hasSameType(field->getType()->getPointeeType(),
@@ -420,13 +423,14 @@ class AggExprEmitter : public StmtVisitor<AggExprEmitter> {
// Length.
cgf.emitStoreThroughLValue(RValue::get(size), endOrLength);
} else {
- cgf.cgm.errorNYI(
- "Aggregate VisitCXXStdInitializerListExpr: field type != sizeTy");
- return;
+ // End pointer.
+ assert(field->getType()->isPointerType() &&
+ ctx.hasSameType(field->getType()->getPointeeType(),
+ arrayType->getElementType()) &&
+ "Expected std::initializer_list second field to be const E *");
+ mlir::Value arrayEnd = builder.createPtrStride(loc, arrayStart, size);
+ cgf.emitStoreThroughLValue(RValue::get(arrayEnd), endOrLength);
}
-
- assert(++field == record->field_end() &&
- "Expected std::initializer_list to only have two fields");
}
void VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *e) {
diff --git a/clang/test/CIR/CodeGen/initializer-list-two-pointers.cpp b/clang/test/CIR/CodeGen/initializer-list-two-pointers.cpp
new file mode 100644
index 0000000000000..913b8a01d890d
--- /dev/null
+++ b/clang/test/CIR/CodeGen/initializer-list-two-pointers.cpp
@@ -0,0 +1,73 @@
+// RUN: %clang_cc1 -std=c++20 -triple x86_64-unknown-linux-gnu -Wno-unused-value -fclangir -emit-cir %s -o %t.cir
+// RUN: FileCheck --input-file=%t.cir %s -check-prefix=CIR
+// RUN: %clang_cc1 -std=c++20 -triple x86_64-unknown-linux-gnu -Wno-unused-value -fclangir -emit-llvm %s -o %t-cir.ll
+// RUN: FileCheck --input-file=%t-cir.ll %s -check-prefix=LLVM
+// RUN: %clang_cc1 -std=c++20 -triple x86_64-unknown-linux-gnu -Wno-unused-value -emit-llvm %s -o %t.ll
+// RUN: FileCheck --input-file=%t.ll %s -check-prefix=OGCG
+
+namespace std {
+template <class _E> class initializer_list {
+ const _E *__begin_;
+ const _E *__end_;
+};
+} // namespace std
+
+void initalizer_list_with_two_pointers_layout() {
+ std::initializer_list<int> a = {10, 20, 30};
+}
+
+// CIR: %[[ARR_ADDR:.*]] = cir.alloca !cir.array<!s32i x 3>, !cir.ptr<!cir.array<!s32i x 3>>, ["ref.tmp0"]
+// CIR: %[[A_ADDR:.*]] = cir.alloca !rec_std3A3Ainitializer_list3Cint3E, !cir.ptr<!rec_std3A3Ainitializer_list3Cint3E>, ["a", init]
+// CIR: cir.scope {
+// CIR: %[[ARR_PTR:.*]] = cir.cast array_to_ptrdecay %[[ARR_ADDR]] : !cir.ptr<!cir.array<!s32i x 3>> -> !cir.ptr<!s32i>
+// CIR: %[[CONST_S32_10:.*]] = cir.const #cir.int<10> : !s32i
+// CIR: cir.store {{.*}} %[[CONST_S32_10]], %[[ARR_PTR]] : !s32i, !cir.ptr<!s32i>
+// CIR: %[[CONST_S64_1:.*]] = cir.const #cir.int<1> : !s64i
+// CIR: %[[ARR_ELEM_1_PTR:.*]] = cir.ptr_stride %[[ARR_PTR]], %[[CONST_S64_1]] : (!cir.ptr<!s32i>, !s64i) -> !cir.ptr<!s32i>
+// CIR: %[[CONST_S32_20:.*]] = cir.const #cir.int<20> : !s32i
+// CIR: cir.store {{.*}} %[[CONST_S32_20]], %[[ARR_ELEM_1_PTR]] : !s32i, !cir.ptr<!s32i>
+// CIR: %[[CONST_S64_2:.*]] = cir.const #cir.int<2> : !s64i
+// CIR: %[[ARR_ELEM_2_PTR:.*]] = cir.ptr_stride %[[ARR_PTR]], %[[CONST_S64_2]] : (!cir.ptr<!s32i>, !s64i) -> !cir.ptr<!s32i>
+// CIR: %[[CONST_S32_30:.*]] = cir.const #cir.int<30> : !s32i
+// CIR: cir.store {{.*}} %[[CONST_S32_30]], %[[ARR_ELEM_2_PTR]] : !s32i, !cir.ptr<!s32i>
+// CIR: %[[BEGIN_PTR:.*]] = cir.get_member %[[A_ADDR]][0] {name = "__begin_"} : !cir.ptr<!rec_std3A3Ainitializer_list3Cint3E> -> !cir.ptr<!cir.ptr<!s32i>
+// CIR: %[[ARR_BEGIN_PTR:.*]] = cir.cast bitcast %[[BEGIN_PTR]] : !cir.ptr<!cir.ptr<!s32i>> -> !cir.ptr<!cir.ptr<!cir.array<!s32i x 3>>>
+// CIR: cir.store {{.*}} %[[ARR_ADDR]], %[[ARR_BEGIN_PTR]] : !cir.ptr<!cir.array<!s32i x 3>>, !cir.ptr<!cir.ptr<!cir.array<!s32i x 3>>>
+// CIR: %[[CONST_U64_3:.*]] = cir.const #cir.int<3> : !u64i
+// CIR: %[[END_PTR:.*]] = cir.get_member %[[A_ADDR]][1] {name = "__end_"} : !cir.ptr<!rec_std3A3Ainitializer_list3Cint3E> -> !cir.ptr<!cir.ptr<!s32i>>
+// CIR: %[[ARR_END:.*]] = cir.ptr_stride %[[ARR_ADDR]], %[[CONST_U64_3]] : (!cir.ptr<!cir.array<!s32i x 3>>, !u64i) -> !cir.ptr<!cir.array<!s32i x 3>>
+// CIR: %[[ARR_END_PTR:.*]] = cir.cast bitcast %[[END_PTR]] : !cir.ptr<!cir.ptr<!s32i>> -> !cir.ptr<!cir.ptr<!cir.array<!s32i x 3>>>
+// CIR: cir.store {{.*}} %[[ARR_END]], %[[ARR_END_PTR]] : !cir.ptr<!cir.array<!s32i x 3>>, !cir.ptr<!cir.ptr<!cir.array<!s32i x 3>>>
+// CIR: }
+
+// LLVM: %[[ARR_ADDR:.*]] = alloca [3 x i32], i64 1, align 4
+// LLVM: %[[A_ADDR:.*]] = alloca %"class.std::initializer_list<int>", i64 1, align 8
+// LLVM: br label %[[SCOPE_BEGIN:.*]]
+// LLVM: [[SCOPE_BEGIN]]:
+// LLVM: %[[ARR_ELEM_0_PTR:.*]] = getelementptr i32, ptr %[[ARR_ADDR]], i32 0
+// LLVM: store i32 10, ptr %[[ARR_ELEM_0_PTR]], align 4
+// LLVM: %[[ARR_ELEM_1_PTR:.*]] = getelementptr i32, ptr %[[ARR_ELEM_0_PTR]], i64 1
+// LLVM: store i32 20, ptr %[[ARR_ELEM_1_PTR]], align 4
+// LLVM: %[[ARR_ELEM_2_PTR:.*]] = getelementptr i32, ptr %[[ARR_ELEM_0_PTR]], i64 2
+// LLVM: store i32 30, ptr %[[ARR_ELEM_2_PTR]], align 4
+// LLVM: %[[BEGIN_PTR:.*]] = getelementptr %"class.std::initializer_list<int>", ptr %[[A_ADDR]], i32 0, i32 0
+// LLVM: store ptr %[[ARR_ADDR]], ptr %[[BEGIN_PTR]], align 8
+// LLVM: %[[END_PTR:.*]] = getelementptr %"class.std::initializer_list<int>", ptr %[[A_ADDR]], i32 0, i32 1
+// LLVM: %[[ARR_END:.*]] = getelementptr [3 x i32], ptr %[[ARR_ADDR]], i64 3
+// LLVM: store ptr %[[ARR_END]], ptr %[[END_PTR]], align 8
+// LLVM: br label %[[SCOPE_END:.*]]
+// LLVM: [[SCOPE_END]]:
+// LLVM: ret void
+
+// OGCG: %[[A_ADDR:.*]] = alloca %"class.std::initializer_list", align 8
+// OGCG: %[[ARR_ADDR:.*]] = alloca [3 x i32], align 4
+// OGCG: store i32 10, ptr %[[ARR_ADDR]], align 4
+// OGCG: %[[ARR_ELEM_1_PTR:.*]] = getelementptr inbounds i32, ptr %[[ARR_ADDR]], i64 1
+// OGCG: store i32 20, ptr %[[ARR_ELEM_1_PTR]], align 4
+// OGCG: %[[ARR_ELEM_2_PTR:.*]] = getelementptr inbounds i32, ptr %[[ARR_ADDR]], i64 2
+// OGCG: store i32 30, ptr %[[ARR_ELEM_2_PTR]], align 4
+// OGCG: %[[BEGIN_PTR:.*]] = getelementptr inbounds nuw %"class.std::initializer_list", ptr %[[A_ADDR]], i32 0, i32 0
+// OGCG: store ptr %[[ARR_ADDR]], ptr %[[BEGIN_PTR]], align 8
+// OGCG: %[[END_PTR:.*]] = getelementptr inbounds nuw %"class.std::initializer_list", ptr %[[A_ADDR]], i32 0, i32 1
+// OGCG: %[[ARR_END:.*]] = getelementptr inbounds [3 x i32], ptr %[[ARR_ADDR]], i64 0, i64 3
+// OGCG: store ptr %[[ARR_END]], ptr %[[END_PTR]], align 8
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