src/base.rs

   1 use crate::prelude::*;
   2
   3 struct PrintOnPanic<F: Fn() -> String>(F);
   4 impl<F: Fn() -> String> Drop for PrintOnPanic<F> {
   5     fn drop(&mut self) {
   6         if ::std::thread::panicking() {
   7             println!("{}", (self.0)());
   8         }
   9     }
  10 }
  11
  12 pub fn trans_mono_item<'a, 'clif, 'tcx: 'a, B: Backend + 'static>(
  13     cx: &mut crate::CodegenCx<'a, 'clif, 'tcx, B>,
  14     mono_item: MonoItem<'tcx>,
  15     linkage: Linkage,
  16 ) {
  17     let tcx = cx.tcx;
  18     match mono_item {
  19         MonoItem::Fn(inst) => {
  20             let _inst_guard =
  21                 PrintOnPanic(|| format!("{:?} {}", inst, tcx.symbol_name(inst).as_str()));
  22             debug_assert!(!inst.substs.needs_infer());
  23             let _mir_guard = PrintOnPanic(|| {
  24                 match inst.def {
  25                     InstanceDef::Item(_)
  26                     | InstanceDef::DropGlue(_, _)
  27                     | InstanceDef::Virtual(_, _)
  28                         if inst.def_id().krate == LOCAL_CRATE =>
  29                     {
  30                         let mut mir = ::std::io::Cursor::new(Vec::new());
  31                         crate::rustc_mir::util::write_mir_pretty(
  32                             tcx,
  33                             Some(inst.def_id()),
  34                             &mut mir,
  35                         )
  36                         .unwrap();
  37                         String::from_utf8(mir.into_inner()).unwrap()
  38                     }
  39                     _ => {
  40                         // FIXME fix write_mir_pretty for these instances
  41                         format!("{:#?}", tcx.instance_mir(inst.def))
  42                     }
  43                 }
  44             });
  45
  46             trans_fn(cx, inst, linkage);
  47         }
  48         MonoItem::Static(def_id) => {
  49             crate::constant::codegen_static(&mut cx.ccx, def_id);
  50         }
  51         MonoItem::GlobalAsm(node_id) => tcx
  52             .sess
  53             .fatal(&format!("Unimplemented global asm mono item {:?}", node_id)),
  54     }
  55 }
  56
  57 fn trans_fn<'a, 'clif, 'tcx: 'a, B: Backend + 'static>(
  58     cx: &mut crate::CodegenCx<'a, 'clif, 'tcx, B>,
  59     instance: Instance<'tcx>,
  60     linkage: Linkage,
  61 ) {
  62     let tcx = cx.tcx;
  63
  64     // Step 1. Get mir
  65     let mir = tcx.instance_mir(instance.def);
  66
  67     // Step 2. Declare function
  68     let (name, sig) = get_function_name_and_sig(tcx, instance);
  69     let func_id = cx.module
  70         .declare_function(&name, linkage, &sig)
  71         .unwrap();
  72
  73     // Step 3. Make FunctionBuilder
  74     let mut func = Function::with_name_signature(ExternalName::user(0, 0), sig);
  75     let mut func_ctx = FunctionBuilderContext::new();
  76     let mut bcx = FunctionBuilder::new(&mut func, &mut func_ctx);
  77
  78     // Step 4. Predefine ebb's
  79     let start_ebb = bcx.create_ebb();
  80     let mut ebb_map: HashMap<BasicBlock, Ebb> = HashMap::new();
  81     for (bb, _bb_data) in mir.basic_blocks().iter_enumerated() {
  82         ebb_map.insert(bb, bcx.create_ebb());
  83     }
  84
  85     // Step 5. Make FunctionCx
  86     let pointer_type = cx.module.target_config().pointer_type();
  87     let clif_comments = crate::pretty_clif::CommentWriter::new(tcx, instance);
  88
  89     let mut fx = FunctionCx {
  90         tcx,
  91         module: cx.module,
  92         pointer_type,
  93
  94         instance,
  95         mir,
  96
  97         bcx,
  98         ebb_map,
  99         local_map: HashMap::new(),
 100
 101         clif_comments,
 102         constants: &mut cx.ccx,
 103         caches: &mut cx.caches,
 104     };
 105
 106     // Step 6. Codegen function
 107     with_unimpl_span(fx.mir.span, || {
 108         crate::abi::codegen_fn_prelude(&mut fx, start_ebb);
 109         codegen_fn_content(&mut fx);
 110     });
 111
 112     // Step 7. Write function to file for debugging
 113     if cfg!(debug_assertions) {
 114         fx.write_clif_file();
 115     }
 116
 117     // Step 8. Verify function
 118     verify_func(tcx, fx.clif_comments, &func);
 119
 120     // Step 9. Define function
 121     cx.caches.context.func = func;
 122     cx.module
 123         .define_function(func_id, &mut cx.caches.context)
 124         .unwrap();
 125     cx.caches.context.clear();
 126 }
 127
 128 fn verify_func(tcx: TyCtxt, writer: crate::pretty_clif::CommentWriter, func: &Function) {
 129     let flags = settings::Flags::new(settings::builder());
 130     match ::cranelift::codegen::verify_function(&func, &flags) {
 131         Ok(_) => {}
 132         Err(err) => {
 133             tcx.sess.err(&format!("{:?}", err));
 134             let pretty_error = ::cranelift::codegen::print_errors::pretty_verifier_error(
 135                 &func,
 136                 None,
 137                 Some(Box::new(&writer)),
 138                 err,
 139             );
 140             tcx.sess
 141                 .fatal(&format!("cranelift verify error:\n{}", pretty_error));
 142         }
 143     }
 144 }
 145
 146 fn codegen_fn_content<'a, 'tcx: 'a>(fx: &mut FunctionCx<'a, 'tcx, impl Backend>) {
 147     for (bb, bb_data) in fx.mir.basic_blocks().iter_enumerated() {
 148         if bb_data.is_cleanup {
 149             // Unwinding after panicking is not supported
 150             continue;
 151         }
 152
 153         let ebb = fx.get_ebb(bb);
 154         fx.bcx.switch_to_block(ebb);
 155
 156         fx.bcx.ins().nop();
 157         for stmt in &bb_data.statements {
 158             trans_stmt(fx, ebb, stmt);
 159         }
 160
 161         let mut terminator_head = "\n".to_string();
 162         bb_data
 163             .terminator()
 164             .kind
 165             .fmt_head(&mut terminator_head)
 166             .unwrap();
 167         let inst = fx.bcx.func.layout.last_inst(ebb).unwrap();
 168         fx.add_comment(inst, terminator_head);
 169
 170         match &bb_data.terminator().kind {
 171             TerminatorKind::Goto { target } => {
 172                 let ebb = fx.get_ebb(*target);
 173                 fx.bcx.ins().jump(ebb, &[]);
 174             }
 175             TerminatorKind::Return => {
 176                 crate::abi::codegen_return(fx);
 177             }
 178             TerminatorKind::Assert {
 179                 cond,
 180                 expected,
 181                 msg: _,
 182                 target,
 183                 cleanup: _,
 184             } => {
 185                 let cond = trans_operand(fx, cond).load_value(fx);
 186                 // TODO HACK brz/brnz for i8/i16 is not yet implemented
 187                 let cond = fx.bcx.ins().uextend(types::I32, cond);
 188                 let target = fx.get_ebb(*target);
 189                 if *expected {
 190                     fx.bcx.ins().brnz(cond, target, &[]);
 191                 } else {
 192                     fx.bcx.ins().brz(cond, target, &[]);
 193                 };
 194                 trap_panic(&mut fx.bcx);
 195             }
 196
 197             TerminatorKind::SwitchInt {
 198                 discr,
 199                 switch_ty: _,
 200                 values,
 201                 targets,
 202             } => {
 203                 let discr = trans_operand(fx, discr).load_value(fx);
 204                 let mut switch = ::cranelift::frontend::Switch::new();
 205                 for (i, value) in values.iter().enumerate() {
 206                     let ebb = fx.get_ebb(targets[i]);
 207                     switch.set_entry(*value as u64, ebb);
 208                 }
 209                 let otherwise_ebb = fx.get_ebb(targets[targets.len() - 1]);
 210                 switch.emit(&mut fx.bcx, discr, otherwise_ebb);
 211             }
 212             TerminatorKind::Call {
 213                 func,
 214                 args,
 215                 destination,
 216                 cleanup: _,
 217                 from_hir_call: _,
 218             } => {
 219                 crate::abi::codegen_terminator_call(fx, func, args, destination);
 220             }
 221             TerminatorKind::Resume | TerminatorKind::Abort | TerminatorKind::Unreachable => {
 222                 trap_unreachable(&mut fx.bcx);
 223             }
 224             TerminatorKind::Yield { .. }
 225             | TerminatorKind::FalseEdges { .. }
 226             | TerminatorKind::FalseUnwind { .. }
 227             | TerminatorKind::DropAndReplace { .. } => {
 228                 bug!("shouldn't exist at trans {:?}", bb_data.terminator());
 229             }
 230             TerminatorKind::Drop {
 231                 location,
 232                 target,
 233                 unwind: _,
 234             } => {
 235                 let ty = location.ty(fx.mir, fx.tcx).to_ty(fx.tcx);
 236                 let ty = fx.monomorphize(&ty);
 237                 let drop_fn = crate::rustc_mir::monomorphize::resolve_drop_in_place(fx.tcx, ty);
 238
 239                 if let ty::InstanceDef::DropGlue(_, None) = drop_fn.def {
 240                     // we don't actually need to drop anything
 241                 } else {
 242                     let drop_place = trans_place(fx, location);
 243                     let arg_place = CPlace::temp(
 244                         fx,
 245                         fx.tcx.mk_ref(
 246                             &ty::RegionKind::ReErased,
 247                             TypeAndMut {
 248                                 ty,
 249                                 mutbl: crate::rustc::hir::Mutability::MutMutable,
 250                             },
 251                         ),
 252                     );
 253                     drop_place.write_place_ref(fx, arg_place);
 254                     match ty.sty {
 255                         ty::Dynamic(..) => {
 256                             fx.tcx.sess.warn("Drop for trait object");
 257                         }
 258                         _ => {
 259                             let drop_fn_ty = drop_fn.ty(fx.tcx);
 260                             let arg_value = arg_place.to_cvalue(fx);
 261                             crate::abi::codegen_call_inner(
 262                                 fx,
 263                                 None,
 264                                 drop_fn_ty,
 265                                 vec![arg_value],
 266                                 None,
 267                             );
 268                         }
 269                     }
 270                     /*
 271                     let (args1, args2);
 272                     /*let mut args = if let Some(llextra) = place.llextra {
 273                         args2 = [place.llval, llextra];
 274                         &args2[..]
 275                     } else {
 276                         args1 = [place.llval];
 277                         &args1[..]
 278                     };*/
 279                     let (drop_fn, fn_ty) = match ty.sty {
 280                     ty::Dynamic(..) => {
 281                     let fn_ty = drop_fn.ty(bx.cx.tcx);
 282                     let sig = common::ty_fn_sig(bx.cx, fn_ty);
 283                     let sig = bx.tcx().normalize_erasing_late_bound_regions(
 284                     ty::ParamEnv::reveal_all(),
 285                     &sig,
 286                     );
 287                     let fn_ty = FnType::new_vtable(bx.cx, sig, &[]);
 288                     let vtable = args[1];
 289                     args = &args[..1];
 290                     (meth::DESTRUCTOR.get_fn(&bx, vtable, &fn_ty), fn_ty)
 291                     }
 292                     _ => {
 293                     let value = place.to_cvalue(fx);
 294                     (callee::get_fn(bx.cx, drop_fn),
 295                     FnType::of_instance(bx.cx, &drop_fn))
 296                     }
 297                     };
 298                     do_call(self, bx, fn_ty, drop_fn, args,
 299                     Some((ReturnDest::Nothing, target)),
 300                     unwind);*/
 301                 }
 302
 303                 let target_ebb = fx.get_ebb(*target);
 304                 fx.bcx.ins().jump(target_ebb, &[]);
 305             }
 306             TerminatorKind::GeneratorDrop => {
 307                 unimplemented!("terminator GeneratorDrop");
 308             }
 309         };
 310     }
 311
 312     fx.bcx.seal_all_blocks();
 313     fx.bcx.finalize();
 314 }
 315
 316 fn trans_stmt<'a, 'tcx: 'a>(
 317     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 318     cur_ebb: Ebb,
 319     stmt: &Statement<'tcx>,
 320 ) {
 321     let _print_guard = PrintOnPanic(|| format!("stmt {:?}", stmt));
 322
 323     match &stmt.kind {
 324         StatementKind::StorageLive(..) | StatementKind::StorageDead(..) => {} // Those are not very useful
 325         _ => {
 326             let inst = fx.bcx.func.layout.last_inst(cur_ebb).unwrap();
 327             fx.add_comment(inst, format!("{:?}", stmt));
 328         }
 329     }
 330
 331     match &stmt.kind {
 332         StatementKind::SetDiscriminant {
 333             place,
 334             variant_index,
 335         } => {
 336             let place = trans_place(fx, place);
 337             let layout = place.layout();
 338             if layout.for_variant(&*fx, *variant_index).abi == layout::Abi::Uninhabited {
 339                 return;
 340             }
 341             match layout.variants {
 342                 layout::Variants::Single { index } => {
 343                     assert_eq!(index, *variant_index);
 344                 }
 345                 layout::Variants::Tagged { .. } => {
 346                     let ptr = place.place_field(fx, mir::Field::new(0));
 347                     let to = layout
 348                         .ty
 349                         .ty_adt_def()
 350                         .unwrap()
 351                         .discriminant_for_variant(fx.tcx, *variant_index)
 352                         .val;
 353                     let discr = CValue::const_val(fx, ptr.layout().ty, to as u64 as i64);
 354                     ptr.write_cvalue(fx, discr);
 355                 }
 356                 layout::Variants::NicheFilling {
 357                     dataful_variant,
 358                     ref niche_variants,
 359                     niche_start,
 360                     ..
 361                 } => {
 362                     if *variant_index != dataful_variant {
 363                         let niche = place.place_field(fx, mir::Field::new(0));
 364                         //let niche_llty = niche.layout.immediate_llvm_type(bx.cx);
 365                         let niche_value =
 366                             ((variant_index.as_u32() - niche_variants.start().as_u32()) as u128)
 367                                 .wrapping_add(niche_start);
 368                         // FIXME(eddyb) Check the actual primitive type here.
 369                         let niche_llval = if niche_value == 0 {
 370                             CValue::const_val(fx, niche.layout().ty, 0)
 371                         } else {
 372                             CValue::const_val(fx, niche.layout().ty, niche_value as u64 as i64)
 373                         };
 374                         niche.write_cvalue(fx, niche_llval);
 375                     }
 376                 }
 377             }
 378         }
 379         StatementKind::Assign(to_place, rval) => {
 380             let lval = trans_place(fx, to_place);
 381             let dest_layout = lval.layout();
 382             match &**rval {
 383                 Rvalue::Use(operand) => {
 384                     let val = trans_operand(fx, operand);
 385                     lval.write_cvalue(fx, val);
 386                 }
 387                 Rvalue::Ref(_, _, place) => {
 388                     let place = trans_place(fx, place);
 389                     place.write_place_ref(fx, lval);
 390                 }
 391                 Rvalue::BinaryOp(bin_op, lhs, rhs) => {
 392                     let ty = fx.monomorphize(&lhs.ty(fx.mir, fx.tcx));
 393                     let lhs = trans_operand(fx, lhs);
 394                     let rhs = trans_operand(fx, rhs);
 395
 396                     let res = match ty.sty {
 397                         ty::Bool => trans_bool_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 398                         ty::Uint(_) => {
 399                             trans_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, false)
 400                         }
 401                         ty::Int(_) => {
 402                             trans_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, true)
 403                         }
 404                         ty::Float(_) => trans_float_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 405                         ty::Char => trans_char_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 406                         ty::RawPtr(..) => trans_ptr_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 407                         _ => unimplemented!("binop {:?} for {:?}", bin_op, ty),
 408                     };
 409                     lval.write_cvalue(fx, res);
 410                 }
 411                 Rvalue::CheckedBinaryOp(bin_op, lhs, rhs) => {
 412                     let ty = fx.monomorphize(&lhs.ty(fx.mir, fx.tcx));
 413                     let lhs = trans_operand(fx, lhs);
 414                     let rhs = trans_operand(fx, rhs);
 415
 416                     let res = match ty.sty {
 417                         ty::Uint(_) => {
 418                             trans_checked_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, false)
 419                         }
 420                         ty::Int(_) => {
 421                             trans_checked_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, true)
 422                         }
 423                         _ => unimplemented!("checked binop {:?} for {:?}", bin_op, ty),
 424                     };
 425                     lval.write_cvalue(fx, res);
 426                 }
 427                 Rvalue::UnaryOp(un_op, operand) => {
 428                     let operand = trans_operand(fx, operand);
 429                     let layout = operand.layout();
 430                     let val = operand.load_value(fx);
 431                     let res = match un_op {
 432                         UnOp::Not => {
 433                             match layout.ty.sty {
 434                                 ty::Bool => {
 435                                     let val = fx.bcx.ins().uextend(types::I32, val); // WORKAROUND for CraneStation/cranelift#466
 436                                     let res = fx.bcx.ins().icmp_imm(IntCC::Equal, val, 0);
 437                                     fx.bcx.ins().bint(types::I8, res)
 438                                 }
 439                                 ty::Uint(_) | ty::Int(_) => fx.bcx.ins().bnot(val),
 440                                 _ => unimplemented!("un op Not for {:?}", layout.ty),
 441                             }
 442                         }
 443                         UnOp::Neg => match layout.ty.sty {
 444                             ty::Int(_) => {
 445                                 let clif_ty = fx.clif_type(layout.ty).unwrap();
 446                                 let zero = fx.bcx.ins().iconst(clif_ty, 0);
 447                                 fx.bcx.ins().isub(zero, val)
 448                             }
 449                             ty::Float(_) => fx.bcx.ins().fneg(val),
 450                             _ => unimplemented!("un op Neg for {:?}", layout.ty),
 451                         },
 452                     };
 453                     lval.write_cvalue(fx, CValue::ByVal(res, layout));
 454                 }
 455                 Rvalue::Cast(CastKind::ReifyFnPointer, operand, ty) => {
 456                     let operand = trans_operand(fx, operand);
 457                     let layout = fx.layout_of(ty);
 458                     lval.write_cvalue(fx, operand.unchecked_cast_to(layout));
 459                 }
 460                 Rvalue::Cast(CastKind::UnsafeFnPointer, operand, ty) => {
 461                     let operand = trans_operand(fx, operand);
 462                     let layout = fx.layout_of(ty);
 463                     lval.write_cvalue(fx, operand.unchecked_cast_to(layout));
 464                 }
 465                 Rvalue::Cast(CastKind::Misc, operand, to_ty) => {
 466                     let operand = trans_operand(fx, operand);
 467                     let from_ty = operand.layout().ty;
 468                     match (&from_ty.sty, &to_ty.sty) {
 469                         (ty::Ref(..), ty::Ref(..))
 470                         | (ty::Ref(..), ty::RawPtr(..))
 471                         | (ty::RawPtr(..), ty::Ref(..))
 472                         | (ty::RawPtr(..), ty::RawPtr(..))
 473                         | (ty::FnPtr(..), ty::RawPtr(..)) => {
 474                             lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
 475                         }
 476                         (ty::RawPtr(..), ty::Uint(_))
 477                         | (ty::RawPtr(..), ty::Int(_))
 478                         | (ty::FnPtr(..), ty::Uint(_))
 479                             if to_ty.sty == fx.tcx.types.usize.sty
 480                                 || to_ty.sty == fx.tcx.types.isize.sty
 481                                 || fx.clif_type(to_ty).unwrap() == pointer_ty(fx.tcx) =>
 482                         {
 483                             lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
 484                         }
 485                         (ty::Uint(_), ty::RawPtr(..)) if from_ty.sty == fx.tcx.types.usize.sty => {
 486                             lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
 487                         }
 488                         (ty::Char, ty::Uint(_))
 489                         | (ty::Uint(_), ty::Char)
 490                         | (ty::Uint(_), ty::Int(_))
 491                         | (ty::Uint(_), ty::Uint(_)) => {
 492                             let from = operand.load_value(fx);
 493                             let res = crate::common::clif_intcast(
 494                                 fx,
 495                                 from,
 496                                 fx.clif_type(to_ty).unwrap(),
 497                                 false,
 498                             );
 499                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 500                         }
 501                         (ty::Int(_), ty::Int(_)) | (ty::Int(_), ty::Uint(_)) => {
 502                             let from = operand.load_value(fx);
 503                             let res = crate::common::clif_intcast(
 504                                 fx,
 505                                 from,
 506                                 fx.clif_type(to_ty).unwrap(),
 507                                 true,
 508                             );
 509                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 510                         }
 511                         (ty::Float(from_flt), ty::Float(to_flt)) => {
 512                             let from = operand.load_value(fx);
 513                             let res = match (from_flt, to_flt) {
 514                                 (FloatTy::F32, FloatTy::F64) => {
 515                                     fx.bcx.ins().fpromote(types::F64, from)
 516                                 }
 517                                 (FloatTy::F64, FloatTy::F32) => {
 518                                     fx.bcx.ins().fdemote(types::F32, from)
 519                                 }
 520                                 _ => from,
 521                             };
 522                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 523                         }
 524                         (ty::Int(_), ty::Float(_)) => {
 525                             let from_ty = fx.clif_type(from_ty).unwrap();
 526                             let from = operand.load_value(fx);
 527                             // FIXME missing encoding for fcvt_from_sint.f32.i8
 528                             let from = if from_ty == types::I8 || from_ty == types::I16 {
 529                                 fx.bcx.ins().sextend(types::I32, from)
 530                             } else {
 531                                 from
 532                             };
 533                             let f_type = fx.clif_type(to_ty).unwrap();
 534                             let res = fx.bcx.ins().fcvt_from_sint(f_type, from);
 535                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 536                         }
 537                         (ty::Uint(_), ty::Float(_)) => {
 538                             let from_ty = fx.clif_type(from_ty).unwrap();
 539                             let from = operand.load_value(fx);
 540                             // FIXME missing encoding for fcvt_from_uint.f32.i8
 541                             let from = if from_ty == types::I8 || from_ty == types::I16 {
 542                                 fx.bcx.ins().uextend(types::I32, from)
 543                             } else {
 544                                 from
 545                             };
 546                             let f_type = fx.clif_type(to_ty).unwrap();
 547                             let res = fx.bcx.ins().fcvt_from_uint(f_type, from);
 548                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 549                         }
 550                         (ty::Bool, ty::Uint(_)) | (ty::Bool, ty::Int(_)) => {
 551                             let to_ty = fx.clif_type(to_ty).unwrap();
 552                             let from = operand.load_value(fx);
 553                             let res = if to_ty != types::I8 {
 554                                 fx.bcx.ins().uextend(to_ty, from)
 555                             } else {
 556                                 from
 557                             };
 558                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 559                         }
 560                         (ty::Adt(adt_def, _substs), ty::Uint(_)) | (ty::Adt(adt_def, _substs), ty::Int(_)) if adt_def.is_enum() => {
 561                             let discr = trans_get_discriminant(fx, operand, fx.layout_of(to_ty));
 562                             lval.write_cvalue(fx, discr);
 563                         }
 564                         _ => unimpl!("rval misc {:?} {:?}", from_ty, to_ty),
 565                     }
 566                 }
 567                 Rvalue::Cast(CastKind::ClosureFnPointer, operand, ty) => {
 568                     unimplemented!("rval closure_fn_ptr {:?} {:?}", operand, ty)
 569                 }
 570                 Rvalue::Cast(CastKind::Unsize, operand, _ty) => {
 571                     let operand = trans_operand(fx, operand);
 572                     operand.unsize_value(fx, lval);
 573                 }
 574                 Rvalue::Discriminant(place) => {
 575                     let place = trans_place(fx, place).to_cvalue(fx);
 576                     let discr = trans_get_discriminant(fx, place, dest_layout);
 577                     lval.write_cvalue(fx, discr);
 578                 }
 579                 Rvalue::Repeat(operand, times) => {
 580                     let operand = trans_operand(fx, operand);
 581                     for i in 0..*times {
 582                         let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
 583                         let to = lval.place_index(fx, index);
 584                         to.write_cvalue(fx, operand);
 585                     }
 586                 }
 587                 Rvalue::Len(place) => {
 588                     let place = trans_place(fx, place);
 589                     let usize_layout = fx.layout_of(fx.tcx.types.usize);
 590                     let len = codegen_array_len(fx, place);
 591                     lval.write_cvalue(fx, CValue::ByVal(len, usize_layout));
 592                 }
 593                 Rvalue::NullaryOp(NullOp::Box, content_ty) => {
 594                     use rustc::middle::lang_items::ExchangeMallocFnLangItem;
 595
 596                     let usize_type = fx.clif_type(fx.tcx.types.usize).unwrap();
 597                     let layout = fx.layout_of(content_ty);
 598                     let llsize = fx.bcx.ins().iconst(usize_type, layout.size.bytes() as i64);
 599                     let llalign = fx
 600                         .bcx
 601                         .ins()
 602                         .iconst(usize_type, layout.align.abi.bytes() as i64);
 603                     let box_layout = fx.layout_of(fx.tcx.mk_box(content_ty));
 604
 605                     // Allocate space:
 606                     let def_id = match fx.tcx.lang_items().require(ExchangeMallocFnLangItem) {
 607                         Ok(id) => id,
 608                         Err(s) => {
 609                             fx.tcx
 610                                 .sess
 611                                 .fatal(&format!("allocation of `{}` {}", box_layout.ty, s));
 612                         }
 613                     };
 614                     let instance = ty::Instance::mono(fx.tcx, def_id);
 615                     let func_ref = fx.get_function_ref(instance);
 616                     let call = fx.bcx.ins().call(func_ref, &[llsize, llalign]);
 617                     let ptr = fx.bcx.inst_results(call)[0];
 618                     lval.write_cvalue(fx, CValue::ByVal(ptr, box_layout));
 619                 }
 620                 Rvalue::NullaryOp(NullOp::SizeOf, ty) => {
 621                     assert!(lval
 622                         .layout()
 623                         .ty
 624                         .is_sized(fx.tcx.at(DUMMY_SP), ParamEnv::reveal_all()));
 625                     let ty_size = fx.layout_of(ty).size.bytes();
 626                     let val = CValue::const_val(fx, fx.tcx.types.usize, ty_size as i64);
 627                     lval.write_cvalue(fx, val);
 628                 }
 629                 Rvalue::Aggregate(kind, operands) => match **kind {
 630                     AggregateKind::Array(_ty) => {
 631                         for (i, operand) in operands.into_iter().enumerate() {
 632                             let operand = trans_operand(fx, operand);
 633                             let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
 634                             let to = lval.place_index(fx, index);
 635                             to.write_cvalue(fx, operand);
 636                         }
 637                     }
 638                     _ => unimpl!("shouldn't exist at trans {:?}", rval),
 639                 },
 640             }
 641         }
 642         StatementKind::StorageLive(_)
 643         | StatementKind::StorageDead(_)
 644         | StatementKind::Nop
 645         | StatementKind::FakeRead(..)
 646         | StatementKind::Retag { .. }
 647         | StatementKind::AscribeUserType(..) => {}
 648
 649         StatementKind::InlineAsm { .. } => unimpl!("Inline assembly is not supported"),
 650     }
 651 }
 652
 653 fn codegen_array_len<'a, 'tcx: 'a>(
 654     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 655     place: CPlace<'tcx>,
 656 ) -> Value {
 657     match place.layout().ty.sty {
 658         ty::Array(_elem_ty, len) => {
 659             let len = crate::constant::force_eval_const(fx, len).unwrap_usize(fx.tcx) as i64;
 660             fx.bcx.ins().iconst(fx.pointer_type, len)
 661         }
 662         ty::Slice(_elem_ty) => match place {
 663             CPlace::Addr(_, size, _) => size.unwrap(),
 664             CPlace::Var(_, _) => unreachable!(),
 665         },
 666         _ => bug!("Rvalue::Len({:?})", place),
 667     }
 668 }
 669
 670 pub fn trans_get_discriminant<'a, 'tcx: 'a>(
 671     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 672     value: CValue<'tcx>,
 673     dest_layout: TyLayout<'tcx>,
 674 ) -> CValue<'tcx> {
 675     let layout = value.layout();
 676
 677     if layout.abi == layout::Abi::Uninhabited {
 678         trap_unreachable(&mut fx.bcx);
 679     }
 680     match layout.variants {
 681         layout::Variants::Single { index } => {
 682             let discr_val = layout
 683                 .ty
 684                 .ty_adt_def()
 685                 .map_or(index.as_u32() as u128, |def| {
 686                     def.discriminant_for_variant(fx.tcx, index).val
 687                 });
 688             return CValue::const_val(fx, dest_layout.ty, discr_val as u64 as i64);
 689         }
 690         layout::Variants::Tagged { .. } | layout::Variants::NicheFilling { .. } => {}
 691     }
 692
 693     let discr = value.value_field(fx, mir::Field::new(0));
 694     let discr_ty = discr.layout().ty;
 695     let lldiscr = discr.load_value(fx);
 696     match layout.variants {
 697         layout::Variants::Single { .. } => bug!(),
 698         layout::Variants::Tagged { ref tag, .. } => {
 699             let signed = match tag.value {
 700                 layout::Int(_, signed) => signed,
 701                 _ => false,
 702             };
 703             let val = clif_intcast(fx, lldiscr, fx.clif_type(dest_layout.ty).unwrap(), signed);
 704             return CValue::ByVal(val, dest_layout);
 705         }
 706         layout::Variants::NicheFilling {
 707             dataful_variant,
 708             ref niche_variants,
 709             niche_start,
 710             ..
 711         } => {
 712             let niche_llty = fx.clif_type(discr_ty).unwrap();
 713             let dest_clif_ty = fx.clif_type(dest_layout.ty).unwrap();
 714             if niche_variants.start() == niche_variants.end() {
 715                 let b = fx
 716                     .bcx
 717                     .ins()
 718                     .icmp_imm(IntCC::Equal, lldiscr, niche_start as u64 as i64);
 719                 let if_true = fx
 720                     .bcx
 721                     .ins()
 722                     .iconst(dest_clif_ty, niche_variants.start().as_u32() as i64);
 723                 let if_false = fx
 724                     .bcx
 725                     .ins()
 726                     .iconst(dest_clif_ty, dataful_variant.as_u32() as i64);
 727                 let val = fx.bcx.ins().select(b, if_true, if_false);
 728                 return CValue::ByVal(val, dest_layout);
 729             } else {
 730                 // Rebase from niche values to discriminant values.
 731                 let delta = niche_start.wrapping_sub(niche_variants.start().as_u32() as u128);
 732                 let delta = fx.bcx.ins().iconst(niche_llty, delta as u64 as i64);
 733                 let lldiscr = fx.bcx.ins().isub(lldiscr, delta);
 734                 let b = fx.bcx.ins().icmp_imm(
 735                     IntCC::UnsignedLessThanOrEqual,
 736                     lldiscr,
 737                     niche_variants.end().as_u32() as i64,
 738                 );
 739                 let if_true =
 740                     clif_intcast(fx, lldiscr, fx.clif_type(dest_layout.ty).unwrap(), false);
 741                 let if_false = fx
 742                     .bcx
 743                     .ins()
 744                     .iconst(dest_clif_ty, dataful_variant.as_u32() as i64);
 745                 let val = fx.bcx.ins().select(b, if_true, if_false);
 746                 return CValue::ByVal(val, dest_layout);
 747             }
 748         }
 749     }
 750 }
 751
 752 macro_rules! binop_match {
 753     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, bug) => {
 754         bug!("binop {} on {} lhs: {:?} rhs: {:?}", stringify!($var), $bug_fmt, $lhs, $rhs)
 755     };
 756     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, icmp($cc:ident)) => {{
 757         assert_eq!($fx.tcx.types.bool, $ret_ty);
 758         let ret_layout = $fx.layout_of($ret_ty);
 759
 760         let b = $fx.bcx.ins().icmp(IntCC::$cc, $lhs, $rhs);
 761         CValue::ByVal($fx.bcx.ins().bint(types::I8, b), ret_layout)
 762     }};
 763     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, fcmp($cc:ident)) => {{
 764         assert_eq!($fx.tcx.types.bool, $ret_ty);
 765         let ret_layout = $fx.layout_of($ret_ty);
 766         let b = $fx.bcx.ins().fcmp(FloatCC::$cc, $lhs, $rhs);
 767         CValue::ByVal($fx.bcx.ins().bint(types::I8, b), ret_layout)
 768     }};
 769     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, custom(|| $body:expr)) => {{
 770         $body
 771     }};
 772     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, $name:ident) => {{
 773         let ret_layout = $fx.layout_of($ret_ty);
 774         CValue::ByVal($fx.bcx.ins().$name($lhs, $rhs), ret_layout)
 775     }};
 776     (
 777         $fx:expr, $bin_op:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, $bug_fmt:expr;
 778         $(
 779             $var:ident ($sign:pat) $name:tt $( ( $($next:tt)* ) )? ;
 780         )*
 781     ) => {{
 782         let lhs = $lhs.load_value($fx);
 783         let rhs = $rhs.load_value($fx);
 784         match ($bin_op, $signed) {
 785             $(
 786                 (BinOp::$var, $sign) => binop_match!(@single $fx, $bug_fmt, $var, $signed, lhs, rhs, $ret_ty, $name $( ( $($next)* ) )?),
 787             )*
 788         }
 789     }}
 790 }
 791
 792 fn trans_bool_binop<'a, 'tcx: 'a>(
 793     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 794     bin_op: BinOp,
 795     lhs: CValue<'tcx>,
 796     rhs: CValue<'tcx>,
 797     ty: Ty<'tcx>,
 798 ) -> CValue<'tcx> {
 799     let res = binop_match! {
 800         fx, bin_op, false, lhs, rhs, ty, "bool";
 801         Add (_) bug;
 802         Sub (_) bug;
 803         Mul (_) bug;
 804         Div (_) bug;
 805         Rem (_) bug;
 806         BitXor (_) bxor;
 807         BitAnd (_) band;
 808         BitOr (_) bor;
 809         Shl (_) bug;
 810         Shr (_) bug;
 811
 812         Eq (_) icmp(Equal);
 813         Lt (_) icmp(UnsignedLessThan);
 814         Le (_) icmp(UnsignedLessThanOrEqual);
 815         Ne (_) icmp(NotEqual);
 816         Ge (_) icmp(UnsignedGreaterThanOrEqual);
 817         Gt (_) icmp(UnsignedGreaterThan);
 818
 819         Offset (_) bug;
 820     };
 821
 822     res
 823 }
 824
 825 pub fn trans_int_binop<'a, 'tcx: 'a>(
 826     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 827     bin_op: BinOp,
 828     lhs: CValue<'tcx>,
 829     rhs: CValue<'tcx>,
 830     out_ty: Ty<'tcx>,
 831     signed: bool,
 832 ) -> CValue<'tcx> {
 833     if bin_op != BinOp::Shl && bin_op != BinOp::Shr {
 834         assert_eq!(
 835             lhs.layout().ty,
 836             rhs.layout().ty,
 837             "int binop requires lhs and rhs of same type"
 838         );
 839     }
 840     binop_match! {
 841         fx, bin_op, signed, lhs, rhs, out_ty, "int/uint";
 842         Add (_) iadd;
 843         Sub (_) isub;
 844         Mul (_) imul;
 845         Div (false) udiv;
 846         Div (true) sdiv;
 847         Rem (false) urem;
 848         Rem (true) srem;
 849         BitXor (_) bxor;
 850         BitAnd (_) band;
 851         BitOr (_) bor;
 852         Shl (_) ishl;
 853         Shr (false) ushr;
 854         Shr (true) sshr;
 855
 856         Eq (_) icmp(Equal);
 857         Lt (false) icmp(UnsignedLessThan);
 858         Lt (true) icmp(SignedLessThan);
 859         Le (false) icmp(UnsignedLessThanOrEqual);
 860         Le (true) icmp(SignedLessThanOrEqual);
 861         Ne (_) icmp(NotEqual);
 862         Ge (false) icmp(UnsignedGreaterThanOrEqual);
 863         Ge (true) icmp(SignedGreaterThanOrEqual);
 864         Gt (false) icmp(UnsignedGreaterThan);
 865         Gt (true) icmp(SignedGreaterThan);
 866
 867         Offset (_) bug;
 868     }
 869 }
 870
 871 pub fn trans_checked_int_binop<'a, 'tcx: 'a>(
 872     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 873     bin_op: BinOp,
 874     in_lhs: CValue<'tcx>,
 875     in_rhs: CValue<'tcx>,
 876     out_ty: Ty<'tcx>,
 877     signed: bool,
 878 ) -> CValue<'tcx> {
 879     if bin_op != BinOp::Shl && bin_op != BinOp::Shr {
 880         assert_eq!(
 881             in_lhs.layout().ty,
 882             in_rhs.layout().ty,
 883             "checked int binop requires lhs and rhs of same type"
 884         );
 885     }
 886
 887     let lhs = in_lhs.load_value(fx);
 888     let rhs = in_rhs.load_value(fx);
 889     let res = match bin_op {
 890         BinOp::Add => fx.bcx.ins().iadd(lhs, rhs),
 891         BinOp::Sub => fx.bcx.ins().isub(lhs, rhs),
 892         BinOp::Mul => fx.bcx.ins().imul(lhs, rhs),
 893         BinOp::Shl => fx.bcx.ins().ishl(lhs, rhs),
 894         BinOp::Shr => {
 895             if !signed {
 896                 fx.bcx.ins().ushr(lhs, rhs)
 897             } else {
 898                 fx.bcx.ins().sshr(lhs, rhs)
 899             }
 900         }
 901         _ => bug!(
 902             "binop {:?} on checked int/uint lhs: {:?} rhs: {:?}",
 903             bin_op,
 904             in_lhs,
 905             in_rhs
 906         ),
 907     };
 908
 909     // TODO: check for overflow
 910     let has_overflow = fx.bcx.ins().iconst(types::I8, 0);
 911
 912     let out_place = CPlace::temp(fx, out_ty);
 913     let out_layout = out_place.layout();
 914     out_place.write_cvalue(fx, CValue::ByValPair(res, has_overflow, out_layout));
 915
 916     out_place.to_cvalue(fx)
 917 }
 918
 919 fn trans_float_binop<'a, 'tcx: 'a>(
 920     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 921     bin_op: BinOp,
 922     lhs: CValue<'tcx>,
 923     rhs: CValue<'tcx>,
 924     ty: Ty<'tcx>,
 925 ) -> CValue<'tcx> {
 926     let res = binop_match! {
 927         fx, bin_op, false, lhs, rhs, ty, "float";
 928         Add (_) fadd;
 929         Sub (_) fsub;
 930         Mul (_) fmul;
 931         Div (_) fdiv;
 932         Rem (_) custom(|| {
 933             assert_eq!(lhs.layout().ty, ty);
 934             assert_eq!(rhs.layout().ty, ty);
 935             match ty.sty {
 936                 ty::Float(FloatTy::F32) => fx.easy_call("fmodf", &[lhs, rhs], ty),
 937                 ty::Float(FloatTy::F64) => fx.easy_call("fmod", &[lhs, rhs], ty),
 938                 _ => bug!(),
 939             }
 940         });
 941         BitXor (_) bxor;
 942         BitAnd (_) band;
 943         BitOr (_) bor;
 944         Shl (_) bug;
 945         Shr (_) bug;
 946
 947         Eq (_) fcmp(Equal);
 948         Lt (_) fcmp(LessThan);
 949         Le (_) fcmp(LessThanOrEqual);
 950         Ne (_) fcmp(NotEqual);
 951         Ge (_) fcmp(GreaterThanOrEqual);
 952         Gt (_) fcmp(GreaterThan);
 953
 954         Offset (_) bug;
 955     };
 956
 957     res
 958 }
 959
 960 fn trans_char_binop<'a, 'tcx: 'a>(
 961     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 962     bin_op: BinOp,
 963     lhs: CValue<'tcx>,
 964     rhs: CValue<'tcx>,
 965     ty: Ty<'tcx>,
 966 ) -> CValue<'tcx> {
 967     let res = binop_match! {
 968         fx, bin_op, false, lhs, rhs, ty, "char";
 969         Add (_) bug;
 970         Sub (_) bug;
 971         Mul (_) bug;
 972         Div (_) bug;
 973         Rem (_) bug;
 974         BitXor (_) bug;
 975         BitAnd (_) bug;
 976         BitOr (_) bug;
 977         Shl (_) bug;
 978         Shr (_) bug;
 979
 980         Eq (_) icmp(Equal);
 981         Lt (_) icmp(UnsignedLessThan);
 982         Le (_) icmp(UnsignedLessThanOrEqual);
 983         Ne (_) icmp(NotEqual);
 984         Ge (_) icmp(UnsignedGreaterThanOrEqual);
 985         Gt (_) icmp(UnsignedGreaterThan);
 986
 987         Offset (_) bug;
 988     };
 989
 990     res
 991 }
 992
 993 fn trans_ptr_binop<'a, 'tcx: 'a>(
 994     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 995     bin_op: BinOp,
 996     lhs: CValue<'tcx>,
 997     rhs: CValue<'tcx>,
 998     ret_ty: Ty<'tcx>,
 999 ) -> CValue<'tcx> {
1000     match lhs.layout().ty.sty {
1001         ty::RawPtr(TypeAndMut { ty, mutbl: _ }) => {
1002             if ty.is_sized(fx.tcx.at(DUMMY_SP), ParamEnv::reveal_all()) {
1003                 binop_match! {
1004                     fx, bin_op, false, lhs, rhs, ret_ty, "ptr";
1005                     Add (_) bug;
1006                     Sub (_) bug;
1007                     Mul (_) bug;
1008                     Div (_) bug;
1009                     Rem (_) bug;
1010                     BitXor (_) bug;
1011                     BitAnd (_) bug;
1012                     BitOr (_) bug;
1013                     Shl (_) bug;
1014                     Shr (_) bug;
1015
1016                     Eq (_) icmp(Equal);
1017                     Lt (_) icmp(UnsignedLessThan);
1018                     Le (_) icmp(UnsignedLessThanOrEqual);
1019                     Ne (_) icmp(NotEqual);
1020                     Ge (_) icmp(UnsignedGreaterThanOrEqual);
1021                     Gt (_) icmp(UnsignedGreaterThan);
1022
1023                     Offset (_) iadd;
1024                 }
1025             } else {
1026                 let lhs = lhs.load_value_pair(fx).0;
1027                 let rhs = rhs.load_value_pair(fx).0;
1028                 let res = match bin_op {
1029                     BinOp::Eq => fx.bcx.ins().icmp(IntCC::Equal, lhs, rhs),
1030                     BinOp::Ne => fx.bcx.ins().icmp(IntCC::NotEqual, lhs, rhs),
1031                     _ => unimplemented!(
1032                         "trans_ptr_binop({:?}, <fat ptr>, <fat ptr>) not implemented",
1033                         bin_op
1034                     ),
1035                 };
1036
1037                 assert_eq!(fx.tcx.types.bool, ret_ty);
1038                 let ret_layout = fx.layout_of(ret_ty);
1039                 CValue::ByVal(fx.bcx.ins().bint(types::I8, res), ret_layout)
1040             }
1041         }
1042         _ => bug!("trans_ptr_binop on non ptr"),
1043     }
1044 }
1045
1046 pub fn trans_place<'a, 'tcx: 'a>(
1047     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1048     place: &Place<'tcx>,
1049 ) -> CPlace<'tcx> {
1050     match place {
1051         Place::Local(local) => fx.get_local_place(*local),
1052         Place::Promoted(promoted) => crate::constant::trans_promoted(fx, promoted.0),
1053         Place::Static(static_) => crate::constant::codegen_static_ref(fx, static_),
1054         Place::Projection(projection) => {
1055             let base = trans_place(fx, &projection.base);
1056             match projection.elem {
1057                 ProjectionElem::Deref => base.place_deref(fx),
1058                 ProjectionElem::Field(field, _ty) => base.place_field(fx, field),
1059                 ProjectionElem::Index(local) => {
1060                     let index = fx.get_local_place(local).to_cvalue(fx).load_value(fx);
1061                     base.place_index(fx, index)
1062                 }
1063                 ProjectionElem::ConstantIndex {
1064                     offset,
1065                     min_length: _,
1066                     from_end,
1067                 } => {
1068                     let index = if !from_end {
1069                         fx.bcx.ins().iconst(fx.pointer_type, offset as i64)
1070                     } else {
1071                         let len = codegen_array_len(fx, base);
1072                         fx.bcx.ins().iadd_imm(len, -(offset as i64))
1073                     };
1074                     base.place_index(fx, index)
1075                 }
1076                 ProjectionElem::Subslice { from, to } => unimpl!(
1077                     "projection subslice {:?} from {} to {}",
1078                     projection.base,
1079                     from,
1080                     to
1081                 ),
1082                 ProjectionElem::Downcast(_adt_def, variant) => base.downcast_variant(fx, variant),
1083             }
1084         }
1085     }
1086 }
1087
1088 pub fn trans_operand<'a, 'tcx>(
1089     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1090     operand: &Operand<'tcx>,
1091 ) -> CValue<'tcx> {
1092     match operand {
1093         Operand::Move(place) | Operand::Copy(place) => {
1094             let cplace = trans_place(fx, place);
1095             cplace.to_cvalue(fx)
1096         }
1097         Operand::Constant(const_) => crate::constant::trans_constant(fx, const_),
1098     }
1099 }