From beeb8510aed8205484b668b418d4fbb93af960c1 Mon Sep 17 00:00:00 2001
From: AmrDeveloper <amr96@programmer.net>
Date: Tue, 19 Aug 2025 11:23:10 +0200
Subject: [PATCH] [CIR] Backport MemberExpr support for ComplexType

---
 clang/lib/CIR/CodeGen/CIRGenExpr.cpp        |  4 +++-
 clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp |  9 +++++++-
 clang/test/CIR/CodeGen/complex.cpp          | 23 +++++++++++++++++++++
 3 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/clang/lib/CIR/CodeGen/CIRGenExpr.cpp b/clang/lib/CIR/CodeGen/CIRGenExpr.cpp
index a7d82534383b..a46f1252180c 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExpr.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExpr.cpp
@@ -3270,7 +3270,9 @@ CIRGenFunction::tryEmitAsConstant(DeclRefExpr *refExpr) {
 
 CIRGenFunction::ConstantEmission
 CIRGenFunction::tryEmitAsConstant(const MemberExpr *ME) {
-  llvm_unreachable("NYI");
+  if (DeclRefExpr *dre = tryToConvertMemberExprToDeclRefExpr(*this, ME))
+    return tryEmitAsConstant(dre);
+  return ConstantEmission();
 }
 
 mlir::Value CIRGenFunction::emitScalarConstant(
diff --git a/clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp b/clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp
index c9b4ac21be2d..891dd456ba2f 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp
@@ -109,7 +109,14 @@ class ComplexExprEmitter : public StmtVisitor<ComplexExprEmitter, mlir::Value> {
     llvm_unreachable("NYI");
   }
   mlir::Value VisitArraySubscriptExpr(Expr *E) { return emitLoadOfLValue(E); }
-  mlir::Value VisitMemberExpr(MemberExpr *ME) { llvm_unreachable("NYI"); }
+
+  mlir::Value VisitMemberExpr(MemberExpr *ME) {
+    if (CIRGenFunction::ConstantEmission constant = CGF.tryEmitAsConstant(ME)) {
+      llvm_unreachable("VisitMemberExpr tryEmitAsConstant");
+    }
+    return emitLoadOfLValue(ME);
+  }
+
   mlir::Value VisitOpaqueValueExpr(OpaqueValueExpr *E) {
     llvm_unreachable("NYI");
   }
diff --git a/clang/test/CIR/CodeGen/complex.cpp b/clang/test/CIR/CodeGen/complex.cpp
index 8f639b8248ad..2b8fd573245f 100644
--- a/clang/test/CIR/CodeGen/complex.cpp
+++ b/clang/test/CIR/CodeGen/complex.cpp
@@ -85,3 +85,26 @@ int _Complex complex_real_operator_on_rvalue() {
 // LLVM: store { i32, i32 } zeroinitializer, ptr %[[RET_ADDR]], align 4
 // LLVM: %[[TMP_RET:.*]] = load { i32, i32 }, ptr %[[RET_ADDR]], align 4
 // LLVM: ret { i32, i32 } %[[TMP_RET]]
+
+void complex_member_expr() {
+  struct Wrapper {
+    int _Complex c;
+  };
+
+  Wrapper w;
+  int r = __real__ w.c;
+}
+
+// CIR: %[[W_ADDR:.*]] = cir.alloca !rec_Wrapper, !cir.ptr<!rec_Wrapper>, ["w"]
+// CIR: %[[REAL_ADDR:.*]] = cir.alloca !s32i, !cir.ptr<!s32i>, ["r", init]
+// CIR: %[[ELEM_PTR:.*]] = cir.get_member %[[W_ADDR]][0] {name = "c"} : !cir.ptr<!rec_Wrapper> -> !cir.ptr<!cir.complex<!s32i>>
+// CIR: %[[TMP_ELEM_PTR:.*]] = cir.load{{.*}} %[[ELEM_PTR]] : !cir.ptr<!cir.complex<!s32i>>, !cir.complex<!s32i>
+// CIR: %[[REAL:.*]] = cir.complex.real %[[TMP_ELEM_PTR]] : !cir.complex<!s32i> -> !s32i
+// CIR: cir.store{{.*}} %[[REAL]], %[[REAL_ADDR]] : !s32i, !cir.ptr<!s32i>
+
+// LLVM: %[[W_ADDR:.*]] = alloca %struct.Wrapper, i64 1, align 4
+// LLVM: %[[REAL_ADDR:.*]] = alloca i32, i64 1, align 4
+// LLVM: %[[ELEM_PTR:.*]] = getelementptr %struct.Wrapper, ptr %[[W_ADDR]], i32 0, i32 0
+// LLVM: %[[TMP_ELEM_PTR:.*]] = load { i32, i32 }, ptr %[[ELEM_PTR]], align 4
+// LLVM: %[[REAL:.*]] = extractvalue { i32, i32 } %[[TMP_ELEM_PTR]], 0
+// LLVM: store i32 %[[REAL]], ptr %[[REAL_ADDR]], align 4