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