[CIR] Implement cast expression classes as l-values

clang/lib/CIR/CodeGen/CIRGenExpr.cpp

@@ -2710,18 +2710,15 @@ LValue CIRGenFunction::emitLValue(const Expr *E) {
     return emitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
   case Expr::PredefinedExprClass:
     return emitPredefinedLValue(cast<PredefinedExpr>(E));
+  case Expr::ImplicitCastExprClass:
+  case Expr::CStyleCastExprClass:
   case Expr::CXXFunctionalCastExprClass:
+  case Expr::CXXStaticCastExprClass:
+  case Expr::CXXDynamicCastExprClass:
   case Expr::CXXReinterpretCastExprClass:
   case Expr::CXXConstCastExprClass:
   case Expr::CXXAddrspaceCastExprClass:
   case Expr::ObjCBridgedCastExprClass:
-    emitError(getLoc(E->getExprLoc()), "l-value not implemented for '")
-        << E->getStmtClassName() << "'";
-    assert(0 && "Use emitCastLValue below, remove me when adding testcase");
-  case Expr::CStyleCastExprClass:
-  case Expr::CXXStaticCastExprClass:
-  case Expr::CXXDynamicCastExprClass:
-  case Expr::ImplicitCastExprClass:
     return emitCastLValue(cast<CastExpr>(E));
   case Expr::OpaqueValueExprClass:
     return emitOpaqueValueLValue(cast<OpaqueValueExpr>(E));

clang/test/CIR/CodeGen/cast-lvalue.cpp

@@ -0,0 +1,47 @@
+// RUN: %clang_cc1 -std=c++17 -triple x86_64-unknown-linux-gnu -fclangir -emit-cir %s -o %t.cir
+// RUN: FileCheck --check-prefix=CIR --input-file=%t.cir %s
+// RUN: %clang_cc1 -std=c++17 -triple x86_64-unknown-linux-gnu -fclangir -emit-llvm %s -o %t.ll
+// RUN: FileCheck --check-prefix=LLVM --input-file=%t.ll %s
+// RUN: %clang_cc1 -std=c++17 -triple x86_64-unknown-linux-gnu -emit-llvm %s -o %t.orig.ll
+// RUN: FileCheck --check-prefix=LLVM --input-file=%t.orig.ll %s
+//
+// Test for cast expressions as l-values (const_cast, reinterpret_cast, etc.)
+
+void const_cast_lvalue() {
+  const int x = 0;
+  const_cast<int&>(x) = 1;
+}
+
+// CIR-LABEL: cir.func dso_local @_Z17const_cast_lvaluev
+// CIR:   %[[X:.*]] = cir.alloca !s32i, {{.*}}, ["x", init, const]
+// CIR:   %[[ZERO:.*]] = cir.const #cir.int<0> : !s32i
+// CIR:   cir.store {{.*}} %[[ZERO]], %[[X]] : !s32i, !cir.ptr<!s32i>
+// CIR:   %[[ONE:.*]] = cir.const #cir.int<1> : !s32i
+// CIR:   cir.store {{.*}} %[[ONE]], %[[X]] : !s32i, !cir.ptr<!s32i>
+// CIR:   cir.return
+
+// LLVM-LABEL: define {{.*}}void @_Z17const_cast_lvaluev
+// LLVM:   %[[X:.*]] = alloca i32
+// LLVM:   store i32 0, ptr %[[X]]
+// LLVM:   store i32 1, ptr %[[X]]
+// LLVM:   ret void
+
+void reinterpret_cast_lvalue() {
+  long x = 0;
+  reinterpret_cast<int&>(x) = 1;
+}
+
+// CIR-LABEL: cir.func dso_local @_Z23reinterpret_cast_lvaluev
+// CIR:   %[[X:.*]] = cir.alloca !s64i, {{.*}}, ["x", init]
+// CIR:   %[[ZERO:.*]] = cir.const #cir.int<0> : !s32i
+// CIR:   cir.store {{.*}} %{{.*}}, %[[X]] : !s64i, !cir.ptr<!s64i>
+// CIR:   %[[ONE:.*]] = cir.const #cir.int<1> : !s32i
+// CIR:   %[[CAST:.*]] = cir.cast bitcast %[[X]] : !cir.ptr<!s64i> -> !cir.ptr<!s32i>
+// CIR:   cir.store {{.*}} %[[ONE]], %[[CAST]] : !s32i, !cir.ptr<!s32i>
+// CIR:   cir.return
+
+// LLVM-LABEL: define {{.*}}void @_Z23reinterpret_cast_lvaluev
+// LLVM:   %[[X:.*]] = alloca i64
+// LLVM:   store i64 0, ptr %[[X]]
+// LLVM:   store i32 1, ptr %[[X]]
+// LLVM:   ret void

clang/test/CIR/crashes/const-cast-lvalue.cpp

@@ -1,5 +1,4 @@
 // RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-cir %s -o %t.cir
-// XFAIL: *
 //
 // CXXConstCastExpr l-value emission not implemented
 // Location: CIRGenExpr.cpp:2799