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     #[cfg(debug_assertions)]
 114     fx.write_clif_file();
 115
 116     // Step 8. Verify function
 117     verify_func(tcx, fx.clif_comments, &func);
 118
 119     // Step 9. Define function
 120     cx.caches.context.func = func;
 121     cx.module
 122         .define_function(func_id, &mut cx.caches.context)
 123         .unwrap();
 124     cx.caches.context.clear();
 125 }
 126
 127 fn verify_func(tcx: TyCtxt, writer: crate::pretty_clif::CommentWriter, func: &Function) {
 128     let flags = settings::Flags::new(settings::builder());
 129     match ::cranelift::codegen::verify_function(&func, &flags) {
 130         Ok(_) => {}
 131         Err(err) => {
 132             tcx.sess.err(&format!("{:?}", err));
 133             let pretty_error = ::cranelift::codegen::print_errors::pretty_verifier_error(
 134                 &func,
 135                 None,
 136                 Some(Box::new(&writer)),
 137                 err,
 138             );
 139             tcx.sess
 140                 .fatal(&format!("cranelift verify error:\n{}", pretty_error));
 141         }
 142     }
 143 }
 144
 145 fn codegen_fn_content<'a, 'tcx: 'a>(fx: &mut FunctionCx<'a, 'tcx, impl Backend>) {
 146     for (bb, bb_data) in fx.mir.basic_blocks().iter_enumerated() {
 147         if bb_data.is_cleanup {
 148             // Unwinding after panicking is not supported
 149             continue;
 150         }
 151
 152         let ebb = fx.get_ebb(bb);
 153         fx.bcx.switch_to_block(ebb);
 154
 155         fx.bcx.ins().nop();
 156         for stmt in &bb_data.statements {
 157             trans_stmt(fx, ebb, stmt);
 158         }
 159
 160         #[cfg(debug_assertions)]
 161         {
 162             let mut terminator_head = "\n".to_string();
 163             bb_data
 164                 .terminator()
 165                 .kind
 166                 .fmt_head(&mut terminator_head)
 167                 .unwrap();
 168             let inst = fx.bcx.func.layout.last_inst(ebb).unwrap();
 169             fx.add_comment(inst, terminator_head);
 170         }
 171
 172         match &bb_data.terminator().kind {
 173             TerminatorKind::Goto { target } => {
 174                 let ebb = fx.get_ebb(*target);
 175                 fx.bcx.ins().jump(ebb, &[]);
 176             }
 177             TerminatorKind::Return => {
 178                 crate::abi::codegen_return(fx);
 179             }
 180             TerminatorKind::Assert {
 181                 cond,
 182                 expected,
 183                 msg: _,
 184                 target,
 185                 cleanup: _,
 186             } => {
 187                 let cond = trans_operand(fx, cond).load_value(fx);
 188                 // TODO HACK brz/brnz for i8/i16 is not yet implemented
 189                 let cond = fx.bcx.ins().uextend(types::I32, cond);
 190                 let target = fx.get_ebb(*target);
 191                 if *expected {
 192                     fx.bcx.ins().brnz(cond, target, &[]);
 193                 } else {
 194                     fx.bcx.ins().brz(cond, target, &[]);
 195                 };
 196                 trap_panic(&mut fx.bcx);
 197             }
 198
 199             TerminatorKind::SwitchInt {
 200                 discr,
 201                 switch_ty: _,
 202                 values,
 203                 targets,
 204             } => {
 205                 let discr = trans_operand(fx, discr).load_value(fx);
 206                 let mut switch = ::cranelift::frontend::Switch::new();
 207                 for (i, value) in values.iter().enumerate() {
 208                     let ebb = fx.get_ebb(targets[i]);
 209                     switch.set_entry(*value as u64, ebb);
 210                 }
 211                 let otherwise_ebb = fx.get_ebb(targets[targets.len() - 1]);
 212                 switch.emit(&mut fx.bcx, discr, otherwise_ebb);
 213             }
 214             TerminatorKind::Call {
 215                 func,
 216                 args,
 217                 destination,
 218                 cleanup: _,
 219                 from_hir_call: _,
 220             } => {
 221                 crate::abi::codegen_terminator_call(fx, func, args, destination);
 222             }
 223             TerminatorKind::Resume | TerminatorKind::Abort | TerminatorKind::Unreachable => {
 224                 trap_unreachable(&mut fx.bcx);
 225             }
 226             TerminatorKind::Yield { .. }
 227             | TerminatorKind::FalseEdges { .. }
 228             | TerminatorKind::FalseUnwind { .. }
 229             | TerminatorKind::DropAndReplace { .. } => {
 230                 bug!("shouldn't exist at trans {:?}", bb_data.terminator());
 231             }
 232             TerminatorKind::Drop {
 233                 location,
 234                 target,
 235                 unwind: _,
 236             } => {
 237                 let ty = location.ty(fx.mir, fx.tcx).to_ty(fx.tcx);
 238                 let ty = fx.monomorphize(&ty);
 239                 let drop_fn = crate::rustc_mir::monomorphize::resolve_drop_in_place(fx.tcx, ty);
 240
 241                 if let ty::InstanceDef::DropGlue(_, None) = drop_fn.def {
 242                     // we don't actually need to drop anything
 243                 } else {
 244                     let drop_place = trans_place(fx, location);
 245                     let arg_place = CPlace::temp(
 246                         fx,
 247                         fx.tcx.mk_ref(
 248                             &ty::RegionKind::ReErased,
 249                             TypeAndMut {
 250                                 ty,
 251                                 mutbl: crate::rustc::hir::Mutability::MutMutable,
 252                             },
 253                         ),
 254                     );
 255                     drop_place.write_place_ref(fx, arg_place);
 256                     match ty.sty {
 257                         ty::Dynamic(..) => {
 258                             fx.tcx.sess.warn("Drop for trait object");
 259                         }
 260                         _ => {
 261                             let drop_fn_ty = drop_fn.ty(fx.tcx);
 262                             let arg_value = arg_place.to_cvalue(fx);
 263                             crate::abi::codegen_call_inner(
 264                                 fx,
 265                                 None,
 266                                 drop_fn_ty,
 267                                 vec![arg_value],
 268                                 None,
 269                             );
 270                         }
 271                     }
 272                     /*
 273                     let (args1, args2);
 274                     /*let mut args = if let Some(llextra) = place.llextra {
 275                         args2 = [place.llval, llextra];
 276                         &args2[..]
 277                     } else {
 278                         args1 = [place.llval];
 279                         &args1[..]
 280                     };*/
 281                     let (drop_fn, fn_ty) = match ty.sty {
 282                     ty::Dynamic(..) => {
 283                     let fn_ty = drop_fn.ty(bx.cx.tcx);
 284                     let sig = common::ty_fn_sig(bx.cx, fn_ty);
 285                     let sig = bx.tcx().normalize_erasing_late_bound_regions(
 286                     ty::ParamEnv::reveal_all(),
 287                     &sig,
 288                     );
 289                     let fn_ty = FnType::new_vtable(bx.cx, sig, &[]);
 290                     let vtable = args[1];
 291                     args = &args[..1];
 292                     (meth::DESTRUCTOR.get_fn(&bx, vtable, &fn_ty), fn_ty)
 293                     }
 294                     _ => {
 295                     let value = place.to_cvalue(fx);
 296                     (callee::get_fn(bx.cx, drop_fn),
 297                     FnType::of_instance(bx.cx, &drop_fn))
 298                     }
 299                     };
 300                     do_call(self, bx, fn_ty, drop_fn, args,
 301                     Some((ReturnDest::Nothing, target)),
 302                     unwind);*/
 303                 }
 304
 305                 let target_ebb = fx.get_ebb(*target);
 306                 fx.bcx.ins().jump(target_ebb, &[]);
 307             }
 308             TerminatorKind::GeneratorDrop => {
 309                 unimplemented!("terminator GeneratorDrop");
 310             }
 311         };
 312     }
 313
 314     fx.bcx.seal_all_blocks();
 315     fx.bcx.finalize();
 316 }
 317
 318 fn trans_stmt<'a, 'tcx: 'a>(
 319     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 320     cur_ebb: Ebb,
 321     stmt: &Statement<'tcx>,
 322 ) {
 323     let _print_guard = PrintOnPanic(|| format!("stmt {:?}", stmt));
 324
 325     #[cfg(debug_assertions)]
 326     match &stmt.kind {
 327         StatementKind::StorageLive(..) | StatementKind::StorageDead(..) => {} // Those are not very useful
 328         _ => {
 329             let inst = fx.bcx.func.layout.last_inst(cur_ebb).unwrap();
 330             fx.add_comment(inst, format!("{:?}", stmt));
 331         }
 332     }
 333
 334     match &stmt.kind {
 335         StatementKind::SetDiscriminant {
 336             place,
 337             variant_index,
 338         } => {
 339             let place = trans_place(fx, place);
 340             let layout = place.layout();
 341             if layout.for_variant(&*fx, *variant_index).abi == layout::Abi::Uninhabited {
 342                 return;
 343             }
 344             match layout.variants {
 345                 layout::Variants::Single { index } => {
 346                     assert_eq!(index, *variant_index);
 347                 }
 348                 layout::Variants::Tagged { .. } => {
 349                     let ptr = place.place_field(fx, mir::Field::new(0));
 350                     let to = layout
 351                         .ty
 352                         .ty_adt_def()
 353                         .unwrap()
 354                         .discriminant_for_variant(fx.tcx, *variant_index)
 355                         .val;
 356                     let discr = CValue::const_val(fx, ptr.layout().ty, to as u64 as i64);
 357                     ptr.write_cvalue(fx, discr);
 358                 }
 359                 layout::Variants::NicheFilling {
 360                     dataful_variant,
 361                     ref niche_variants,
 362                     niche_start,
 363                     ..
 364                 } => {
 365                     if *variant_index != dataful_variant {
 366                         let niche = place.place_field(fx, mir::Field::new(0));
 367                         //let niche_llty = niche.layout.immediate_llvm_type(bx.cx);
 368                         let niche_value =
 369                             ((variant_index.as_u32() - niche_variants.start().as_u32()) as u128)
 370                                 .wrapping_add(niche_start);
 371                         // FIXME(eddyb) Check the actual primitive type here.
 372                         let niche_llval = if niche_value == 0 {
 373                             CValue::const_val(fx, niche.layout().ty, 0)
 374                         } else {
 375                             CValue::const_val(fx, niche.layout().ty, niche_value as u64 as i64)
 376                         };
 377                         niche.write_cvalue(fx, niche_llval);
 378                     }
 379                 }
 380             }
 381         }
 382         StatementKind::Assign(to_place, rval) => {
 383             let lval = trans_place(fx, to_place);
 384             let dest_layout = lval.layout();
 385             match &**rval {
 386                 Rvalue::Use(operand) => {
 387                     let val = trans_operand(fx, operand);
 388                     lval.write_cvalue(fx, val);
 389                 }
 390                 Rvalue::Ref(_, _, place) => {
 391                     let place = trans_place(fx, place);
 392                     place.write_place_ref(fx, lval);
 393                 }
 394                 Rvalue::BinaryOp(bin_op, lhs, rhs) => {
 395                     let ty = fx.monomorphize(&lhs.ty(fx.mir, fx.tcx));
 396                     let lhs = trans_operand(fx, lhs);
 397                     let rhs = trans_operand(fx, rhs);
 398
 399                     let res = match ty.sty {
 400                         ty::Bool => trans_bool_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 401                         ty::Uint(_) => {
 402                             trans_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, false)
 403                         }
 404                         ty::Int(_) => {
 405                             trans_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, true)
 406                         }
 407                         ty::Float(_) => trans_float_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 408                         ty::Char => trans_char_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 409                         ty::RawPtr(..) => trans_ptr_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 410                         _ => unimplemented!("binop {:?} for {:?}", bin_op, ty),
 411                     };
 412                     lval.write_cvalue(fx, res);
 413                 }
 414                 Rvalue::CheckedBinaryOp(bin_op, lhs, rhs) => {
 415                     let ty = fx.monomorphize(&lhs.ty(fx.mir, fx.tcx));
 416                     let lhs = trans_operand(fx, lhs);
 417                     let rhs = trans_operand(fx, rhs);
 418
 419                     let res = match ty.sty {
 420                         ty::Uint(_) => {
 421                             trans_checked_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, false)
 422                         }
 423                         ty::Int(_) => {
 424                             trans_checked_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, true)
 425                         }
 426                         _ => unimplemented!("checked binop {:?} for {:?}", bin_op, ty),
 427                     };
 428                     lval.write_cvalue(fx, res);
 429                 }
 430                 Rvalue::UnaryOp(un_op, operand) => {
 431                     let operand = trans_operand(fx, operand);
 432                     let layout = operand.layout();
 433                     let val = operand.load_value(fx);
 434                     let res = match un_op {
 435                         UnOp::Not => {
 436                             match layout.ty.sty {
 437                                 ty::Bool => {
 438                                     let val = fx.bcx.ins().uextend(types::I32, val); // WORKAROUND for CraneStation/cranelift#466
 439                                     let res = fx.bcx.ins().icmp_imm(IntCC::Equal, val, 0);
 440                                     fx.bcx.ins().bint(types::I8, res)
 441                                 }
 442                                 ty::Uint(_) | ty::Int(_) => fx.bcx.ins().bnot(val),
 443                                 _ => unimplemented!("un op Not for {:?}", layout.ty),
 444                             }
 445                         }
 446                         UnOp::Neg => match layout.ty.sty {
 447                             ty::Int(_) => {
 448                                 let clif_ty = fx.clif_type(layout.ty).unwrap();
 449                                 let zero = fx.bcx.ins().iconst(clif_ty, 0);
 450                                 fx.bcx.ins().isub(zero, val)
 451                             }
 452                             ty::Float(_) => fx.bcx.ins().fneg(val),
 453                             _ => unimplemented!("un op Neg for {:?}", layout.ty),
 454                         },
 455                     };
 456                     lval.write_cvalue(fx, CValue::ByVal(res, layout));
 457                 }
 458                 Rvalue::Cast(CastKind::ReifyFnPointer, 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::UnsafeFnPointer, operand, ty) => {
 464                     let operand = trans_operand(fx, operand);
 465                     let layout = fx.layout_of(ty);
 466                     lval.write_cvalue(fx, operand.unchecked_cast_to(layout));
 467                 }
 468                 Rvalue::Cast(CastKind::Misc, operand, to_ty) => {
 469                     let operand = trans_operand(fx, operand);
 470                     let from_ty = operand.layout().ty;
 471                     match (&from_ty.sty, &to_ty.sty) {
 472                         (ty::Ref(..), ty::Ref(..))
 473                         | (ty::Ref(..), ty::RawPtr(..))
 474                         | (ty::RawPtr(..), ty::Ref(..))
 475                         | (ty::RawPtr(..), ty::RawPtr(..))
 476                         | (ty::FnPtr(..), ty::RawPtr(..)) => {
 477                             lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
 478                         }
 479                         (ty::RawPtr(..), ty::Uint(_))
 480                         | (ty::RawPtr(..), ty::Int(_))
 481                         | (ty::FnPtr(..), ty::Uint(_))
 482                             if to_ty.sty == fx.tcx.types.usize.sty
 483                                 || to_ty.sty == fx.tcx.types.isize.sty
 484                                 || fx.clif_type(to_ty).unwrap() == pointer_ty(fx.tcx) =>
 485                         {
 486                             lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
 487                         }
 488                         (ty::Uint(_), ty::RawPtr(..)) if from_ty.sty == fx.tcx.types.usize.sty => {
 489                             lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
 490                         }
 491                         (ty::Char, ty::Uint(_))
 492                         | (ty::Uint(_), ty::Char)
 493                         | (ty::Uint(_), ty::Int(_))
 494                         | (ty::Uint(_), ty::Uint(_)) => {
 495                             let from = operand.load_value(fx);
 496                             let res = crate::common::clif_intcast(
 497                                 fx,
 498                                 from,
 499                                 fx.clif_type(to_ty).unwrap(),
 500                                 false,
 501                             );
 502                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 503                         }
 504                         (ty::Int(_), ty::Int(_)) | (ty::Int(_), ty::Uint(_)) => {
 505                             let from = operand.load_value(fx);
 506                             let res = crate::common::clif_intcast(
 507                                 fx,
 508                                 from,
 509                                 fx.clif_type(to_ty).unwrap(),
 510                                 true,
 511                             );
 512                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 513                         }
 514                         (ty::Float(from_flt), ty::Float(to_flt)) => {
 515                             let from = operand.load_value(fx);
 516                             let res = match (from_flt, to_flt) {
 517                                 (FloatTy::F32, FloatTy::F64) => {
 518                                     fx.bcx.ins().fpromote(types::F64, from)
 519                                 }
 520                                 (FloatTy::F64, FloatTy::F32) => {
 521                                     fx.bcx.ins().fdemote(types::F32, from)
 522                                 }
 523                                 _ => from,
 524                             };
 525                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 526                         }
 527                         (ty::Int(_), ty::Float(_)) => {
 528                             let from_ty = fx.clif_type(from_ty).unwrap();
 529                             let from = operand.load_value(fx);
 530                             // FIXME missing encoding for fcvt_from_sint.f32.i8
 531                             let from = if from_ty == types::I8 || from_ty == types::I16 {
 532                                 fx.bcx.ins().sextend(types::I32, from)
 533                             } else {
 534                                 from
 535                             };
 536                             let f_type = fx.clif_type(to_ty).unwrap();
 537                             let res = fx.bcx.ins().fcvt_from_sint(f_type, from);
 538                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 539                         }
 540                         (ty::Uint(_), ty::Float(_)) => {
 541                             let from_ty = fx.clif_type(from_ty).unwrap();
 542                             let from = operand.load_value(fx);
 543                             // FIXME missing encoding for fcvt_from_uint.f32.i8
 544                             let from = if from_ty == types::I8 || from_ty == types::I16 {
 545                                 fx.bcx.ins().uextend(types::I32, from)
 546                             } else {
 547                                 from
 548                             };
 549                             let f_type = fx.clif_type(to_ty).unwrap();
 550                             let res = fx.bcx.ins().fcvt_from_uint(f_type, from);
 551                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 552                         }
 553                         (ty::Bool, ty::Uint(_)) | (ty::Bool, ty::Int(_)) => {
 554                             let to_ty = fx.clif_type(to_ty).unwrap();
 555                             let from = operand.load_value(fx);
 556                             let res = if to_ty != types::I8 {
 557                                 fx.bcx.ins().uextend(to_ty, from)
 558                             } else {
 559                                 from
 560                             };
 561                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 562                         }
 563                         (ty::Adt(adt_def, _substs), ty::Uint(_)) | (ty::Adt(adt_def, _substs), ty::Int(_)) if adt_def.is_enum() => {
 564                             let discr = trans_get_discriminant(fx, operand, fx.layout_of(to_ty));
 565                             lval.write_cvalue(fx, discr);
 566                         }
 567                         _ => unimpl!("rval misc {:?} {:?}", from_ty, to_ty),
 568                     }
 569                 }
 570                 Rvalue::Cast(CastKind::ClosureFnPointer, operand, ty) => {
 571                     unimplemented!("rval closure_fn_ptr {:?} {:?}", operand, ty)
 572                 }
 573                 Rvalue::Cast(CastKind::Unsize, operand, _ty) => {
 574                     let operand = trans_operand(fx, operand);
 575                     operand.unsize_value(fx, lval);
 576                 }
 577                 Rvalue::Discriminant(place) => {
 578                     let place = trans_place(fx, place).to_cvalue(fx);
 579                     let discr = trans_get_discriminant(fx, place, dest_layout);
 580                     lval.write_cvalue(fx, discr);
 581                 }
 582                 Rvalue::Repeat(operand, times) => {
 583                     let operand = trans_operand(fx, operand);
 584                     for i in 0..*times {
 585                         let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
 586                         let to = lval.place_index(fx, index);
 587                         to.write_cvalue(fx, operand);
 588                     }
 589                 }
 590                 Rvalue::Len(place) => {
 591                     let place = trans_place(fx, place);
 592                     let usize_layout = fx.layout_of(fx.tcx.types.usize);
 593                     let len = codegen_array_len(fx, place);
 594                     lval.write_cvalue(fx, CValue::ByVal(len, usize_layout));
 595                 }
 596                 Rvalue::NullaryOp(NullOp::Box, content_ty) => {
 597                     use rustc::middle::lang_items::ExchangeMallocFnLangItem;
 598
 599                     let usize_type = fx.clif_type(fx.tcx.types.usize).unwrap();
 600                     let layout = fx.layout_of(content_ty);
 601                     let llsize = fx.bcx.ins().iconst(usize_type, layout.size.bytes() as i64);
 602                     let llalign = fx
 603                         .bcx
 604                         .ins()
 605                         .iconst(usize_type, layout.align.abi.bytes() as i64);
 606                     let box_layout = fx.layout_of(fx.tcx.mk_box(content_ty));
 607
 608                     // Allocate space:
 609                     let def_id = match fx.tcx.lang_items().require(ExchangeMallocFnLangItem) {
 610                         Ok(id) => id,
 611                         Err(s) => {
 612                             fx.tcx
 613                                 .sess
 614                                 .fatal(&format!("allocation of `{}` {}", box_layout.ty, s));
 615                         }
 616                     };
 617                     let instance = ty::Instance::mono(fx.tcx, def_id);
 618                     let func_ref = fx.get_function_ref(instance);
 619                     let call = fx.bcx.ins().call(func_ref, &[llsize, llalign]);
 620                     let ptr = fx.bcx.inst_results(call)[0];
 621                     lval.write_cvalue(fx, CValue::ByVal(ptr, box_layout));
 622                 }
 623                 Rvalue::NullaryOp(NullOp::SizeOf, ty) => {
 624                     assert!(lval
 625                         .layout()
 626                         .ty
 627                         .is_sized(fx.tcx.at(DUMMY_SP), ParamEnv::reveal_all()));
 628                     let ty_size = fx.layout_of(ty).size.bytes();
 629                     let val = CValue::const_val(fx, fx.tcx.types.usize, ty_size as i64);
 630                     lval.write_cvalue(fx, val);
 631                 }
 632                 Rvalue::Aggregate(kind, operands) => match **kind {
 633                     AggregateKind::Array(_ty) => {
 634                         for (i, operand) in operands.into_iter().enumerate() {
 635                             let operand = trans_operand(fx, operand);
 636                             let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
 637                             let to = lval.place_index(fx, index);
 638                             to.write_cvalue(fx, operand);
 639                         }
 640                     }
 641                     _ => unimpl!("shouldn't exist at trans {:?}", rval),
 642                 },
 643             }
 644         }
 645         StatementKind::StorageLive(_)
 646         | StatementKind::StorageDead(_)
 647         | StatementKind::Nop
 648         | StatementKind::FakeRead(..)
 649         | StatementKind::Retag { .. }
 650         | StatementKind::AscribeUserType(..) => {}
 651
 652         StatementKind::InlineAsm { .. } => unimpl!("Inline assembly is not supported"),
 653     }
 654 }
 655
 656 fn codegen_array_len<'a, 'tcx: 'a>(
 657     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 658     place: CPlace<'tcx>,
 659 ) -> Value {
 660     match place.layout().ty.sty {
 661         ty::Array(_elem_ty, len) => {
 662             let len = crate::constant::force_eval_const(fx, len).unwrap_usize(fx.tcx) as i64;
 663             fx.bcx.ins().iconst(fx.pointer_type, len)
 664         }
 665         ty::Slice(_elem_ty) => match place {
 666             CPlace::Addr(_, size, _) => size.unwrap(),
 667             CPlace::Var(_, _) => unreachable!(),
 668         },
 669         _ => bug!("Rvalue::Len({:?})", place),
 670     }
 671 }
 672
 673 pub fn trans_get_discriminant<'a, 'tcx: 'a>(
 674     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 675     value: CValue<'tcx>,
 676     dest_layout: TyLayout<'tcx>,
 677 ) -> CValue<'tcx> {
 678     let layout = value.layout();
 679
 680     if layout.abi == layout::Abi::Uninhabited {
 681         trap_unreachable(&mut fx.bcx);
 682     }
 683     match layout.variants {
 684         layout::Variants::Single { index } => {
 685             let discr_val = layout
 686                 .ty
 687                 .ty_adt_def()
 688                 .map_or(index.as_u32() as u128, |def| {
 689                     def.discriminant_for_variant(fx.tcx, index).val
 690                 });
 691             return CValue::const_val(fx, dest_layout.ty, discr_val as u64 as i64);
 692         }
 693         layout::Variants::Tagged { .. } | layout::Variants::NicheFilling { .. } => {}
 694     }
 695
 696     let discr = value.value_field(fx, mir::Field::new(0));
 697     let discr_ty = discr.layout().ty;
 698     let lldiscr = discr.load_value(fx);
 699     match layout.variants {
 700         layout::Variants::Single { .. } => bug!(),
 701         layout::Variants::Tagged { ref tag, .. } => {
 702             let signed = match tag.value {
 703                 layout::Int(_, signed) => signed,
 704                 _ => false,
 705             };
 706             let val = clif_intcast(fx, lldiscr, fx.clif_type(dest_layout.ty).unwrap(), signed);
 707             return CValue::ByVal(val, dest_layout);
 708         }
 709         layout::Variants::NicheFilling {
 710             dataful_variant,
 711             ref niche_variants,
 712             niche_start,
 713             ..
 714         } => {
 715             let niche_llty = fx.clif_type(discr_ty).unwrap();
 716             let dest_clif_ty = fx.clif_type(dest_layout.ty).unwrap();
 717             if niche_variants.start() == niche_variants.end() {
 718                 let b = fx
 719                     .bcx
 720                     .ins()
 721                     .icmp_imm(IntCC::Equal, lldiscr, niche_start as u64 as i64);
 722                 let if_true = fx
 723                     .bcx
 724                     .ins()
 725                     .iconst(dest_clif_ty, niche_variants.start().as_u32() as i64);
 726                 let if_false = fx
 727                     .bcx
 728                     .ins()
 729                     .iconst(dest_clif_ty, dataful_variant.as_u32() as i64);
 730                 let val = fx.bcx.ins().select(b, if_true, if_false);
 731                 return CValue::ByVal(val, dest_layout);
 732             } else {
 733                 // Rebase from niche values to discriminant values.
 734                 let delta = niche_start.wrapping_sub(niche_variants.start().as_u32() as u128);
 735                 let delta = fx.bcx.ins().iconst(niche_llty, delta as u64 as i64);
 736                 let lldiscr = fx.bcx.ins().isub(lldiscr, delta);
 737                 let b = fx.bcx.ins().icmp_imm(
 738                     IntCC::UnsignedLessThanOrEqual,
 739                     lldiscr,
 740                     niche_variants.end().as_u32() as i64,
 741                 );
 742                 let if_true =
 743                     clif_intcast(fx, lldiscr, fx.clif_type(dest_layout.ty).unwrap(), false);
 744                 let if_false = fx
 745                     .bcx
 746                     .ins()
 747                     .iconst(dest_clif_ty, dataful_variant.as_u32() as i64);
 748                 let val = fx.bcx.ins().select(b, if_true, if_false);
 749                 return CValue::ByVal(val, dest_layout);
 750             }
 751         }
 752     }
 753 }
 754
 755 macro_rules! binop_match {
 756     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, bug) => {
 757         bug!("binop {} on {} lhs: {:?} rhs: {:?}", stringify!($var), $bug_fmt, $lhs, $rhs)
 758     };
 759     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, icmp($cc:ident)) => {{
 760         assert_eq!($fx.tcx.types.bool, $ret_ty);
 761         let ret_layout = $fx.layout_of($ret_ty);
 762
 763         let b = $fx.bcx.ins().icmp(IntCC::$cc, $lhs, $rhs);
 764         CValue::ByVal($fx.bcx.ins().bint(types::I8, b), ret_layout)
 765     }};
 766     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, fcmp($cc:ident)) => {{
 767         assert_eq!($fx.tcx.types.bool, $ret_ty);
 768         let ret_layout = $fx.layout_of($ret_ty);
 769         let b = $fx.bcx.ins().fcmp(FloatCC::$cc, $lhs, $rhs);
 770         CValue::ByVal($fx.bcx.ins().bint(types::I8, b), ret_layout)
 771     }};
 772     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, custom(|| $body:expr)) => {{
 773         $body
 774     }};
 775     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, $name:ident) => {{
 776         let ret_layout = $fx.layout_of($ret_ty);
 777         CValue::ByVal($fx.bcx.ins().$name($lhs, $rhs), ret_layout)
 778     }};
 779     (
 780         $fx:expr, $bin_op:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, $bug_fmt:expr;
 781         $(
 782             $var:ident ($sign:pat) $name:tt $( ( $($next:tt)* ) )? ;
 783         )*
 784     ) => {{
 785         let lhs = $lhs.load_value($fx);
 786         let rhs = $rhs.load_value($fx);
 787         match ($bin_op, $signed) {
 788             $(
 789                 (BinOp::$var, $sign) => binop_match!(@single $fx, $bug_fmt, $var, $signed, lhs, rhs, $ret_ty, $name $( ( $($next)* ) )?),
 790             )*
 791         }
 792     }}
 793 }
 794
 795 fn trans_bool_binop<'a, 'tcx: 'a>(
 796     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 797     bin_op: BinOp,
 798     lhs: CValue<'tcx>,
 799     rhs: CValue<'tcx>,
 800     ty: Ty<'tcx>,
 801 ) -> CValue<'tcx> {
 802     let res = binop_match! {
 803         fx, bin_op, false, lhs, rhs, ty, "bool";
 804         Add (_) bug;
 805         Sub (_) bug;
 806         Mul (_) bug;
 807         Div (_) bug;
 808         Rem (_) bug;
 809         BitXor (_) bxor;
 810         BitAnd (_) band;
 811         BitOr (_) bor;
 812         Shl (_) bug;
 813         Shr (_) bug;
 814
 815         Eq (_) icmp(Equal);
 816         Lt (_) icmp(UnsignedLessThan);
 817         Le (_) icmp(UnsignedLessThanOrEqual);
 818         Ne (_) icmp(NotEqual);
 819         Ge (_) icmp(UnsignedGreaterThanOrEqual);
 820         Gt (_) icmp(UnsignedGreaterThan);
 821
 822         Offset (_) bug;
 823     };
 824
 825     res
 826 }
 827
 828 pub fn trans_int_binop<'a, 'tcx: 'a>(
 829     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 830     bin_op: BinOp,
 831     lhs: CValue<'tcx>,
 832     rhs: CValue<'tcx>,
 833     out_ty: Ty<'tcx>,
 834     signed: bool,
 835 ) -> CValue<'tcx> {
 836     if bin_op != BinOp::Shl && bin_op != BinOp::Shr {
 837         assert_eq!(
 838             lhs.layout().ty,
 839             rhs.layout().ty,
 840             "int binop requires lhs and rhs of same type"
 841         );
 842     }
 843     binop_match! {
 844         fx, bin_op, signed, lhs, rhs, out_ty, "int/uint";
 845         Add (_) iadd;
 846         Sub (_) isub;
 847         Mul (_) imul;
 848         Div (false) udiv;
 849         Div (true) sdiv;
 850         Rem (false) urem;
 851         Rem (true) srem;
 852         BitXor (_) bxor;
 853         BitAnd (_) band;
 854         BitOr (_) bor;
 855         Shl (_) ishl;
 856         Shr (false) ushr;
 857         Shr (true) sshr;
 858
 859         Eq (_) icmp(Equal);
 860         Lt (false) icmp(UnsignedLessThan);
 861         Lt (true) icmp(SignedLessThan);
 862         Le (false) icmp(UnsignedLessThanOrEqual);
 863         Le (true) icmp(SignedLessThanOrEqual);
 864         Ne (_) icmp(NotEqual);
 865         Ge (false) icmp(UnsignedGreaterThanOrEqual);
 866         Ge (true) icmp(SignedGreaterThanOrEqual);
 867         Gt (false) icmp(UnsignedGreaterThan);
 868         Gt (true) icmp(SignedGreaterThan);
 869
 870         Offset (_) bug;
 871     }
 872 }
 873
 874 pub fn trans_checked_int_binop<'a, 'tcx: 'a>(
 875     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 876     bin_op: BinOp,
 877     in_lhs: CValue<'tcx>,
 878     in_rhs: CValue<'tcx>,
 879     out_ty: Ty<'tcx>,
 880     signed: bool,
 881 ) -> CValue<'tcx> {
 882     if bin_op != BinOp::Shl && bin_op != BinOp::Shr {
 883         assert_eq!(
 884             in_lhs.layout().ty,
 885             in_rhs.layout().ty,
 886             "checked int binop requires lhs and rhs of same type"
 887         );
 888     }
 889
 890     let lhs = in_lhs.load_value(fx);
 891     let rhs = in_rhs.load_value(fx);
 892     let res = match bin_op {
 893         BinOp::Add => fx.bcx.ins().iadd(lhs, rhs),
 894         BinOp::Sub => fx.bcx.ins().isub(lhs, rhs),
 895         BinOp::Mul => fx.bcx.ins().imul(lhs, rhs),
 896         BinOp::Shl => fx.bcx.ins().ishl(lhs, rhs),
 897         BinOp::Shr => {
 898             if !signed {
 899                 fx.bcx.ins().ushr(lhs, rhs)
 900             } else {
 901                 fx.bcx.ins().sshr(lhs, rhs)
 902             }
 903         }
 904         _ => bug!(
 905             "binop {:?} on checked int/uint lhs: {:?} rhs: {:?}",
 906             bin_op,
 907             in_lhs,
 908             in_rhs
 909         ),
 910     };
 911
 912     // TODO: check for overflow
 913     let has_overflow = fx.bcx.ins().iconst(types::I8, 0);
 914
 915     let out_place = CPlace::temp(fx, out_ty);
 916     let out_layout = out_place.layout();
 917     out_place.write_cvalue(fx, CValue::ByValPair(res, has_overflow, out_layout));
 918
 919     out_place.to_cvalue(fx)
 920 }
 921
 922 fn trans_float_binop<'a, 'tcx: 'a>(
 923     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 924     bin_op: BinOp,
 925     lhs: CValue<'tcx>,
 926     rhs: CValue<'tcx>,
 927     ty: Ty<'tcx>,
 928 ) -> CValue<'tcx> {
 929     let res = binop_match! {
 930         fx, bin_op, false, lhs, rhs, ty, "float";
 931         Add (_) fadd;
 932         Sub (_) fsub;
 933         Mul (_) fmul;
 934         Div (_) fdiv;
 935         Rem (_) custom(|| {
 936             assert_eq!(lhs.layout().ty, ty);
 937             assert_eq!(rhs.layout().ty, ty);
 938             match ty.sty {
 939                 ty::Float(FloatTy::F32) => fx.easy_call("fmodf", &[lhs, rhs], ty),
 940                 ty::Float(FloatTy::F64) => fx.easy_call("fmod", &[lhs, rhs], ty),
 941                 _ => bug!(),
 942             }
 943         });
 944         BitXor (_) bxor;
 945         BitAnd (_) band;
 946         BitOr (_) bor;
 947         Shl (_) bug;
 948         Shr (_) bug;
 949
 950         Eq (_) fcmp(Equal);
 951         Lt (_) fcmp(LessThan);
 952         Le (_) fcmp(LessThanOrEqual);
 953         Ne (_) fcmp(NotEqual);
 954         Ge (_) fcmp(GreaterThanOrEqual);
 955         Gt (_) fcmp(GreaterThan);
 956
 957         Offset (_) bug;
 958     };
 959
 960     res
 961 }
 962
 963 fn trans_char_binop<'a, 'tcx: 'a>(
 964     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 965     bin_op: BinOp,
 966     lhs: CValue<'tcx>,
 967     rhs: CValue<'tcx>,
 968     ty: Ty<'tcx>,
 969 ) -> CValue<'tcx> {
 970     let res = binop_match! {
 971         fx, bin_op, false, lhs, rhs, ty, "char";
 972         Add (_) bug;
 973         Sub (_) bug;
 974         Mul (_) bug;
 975         Div (_) bug;
 976         Rem (_) bug;
 977         BitXor (_) bug;
 978         BitAnd (_) bug;
 979         BitOr (_) bug;
 980         Shl (_) bug;
 981         Shr (_) bug;
 982
 983         Eq (_) icmp(Equal);
 984         Lt (_) icmp(UnsignedLessThan);
 985         Le (_) icmp(UnsignedLessThanOrEqual);
 986         Ne (_) icmp(NotEqual);
 987         Ge (_) icmp(UnsignedGreaterThanOrEqual);
 988         Gt (_) icmp(UnsignedGreaterThan);
 989
 990         Offset (_) bug;
 991     };
 992
 993     res
 994 }
 995
 996 fn trans_ptr_binop<'a, 'tcx: 'a>(
 997     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 998     bin_op: BinOp,
 999     lhs: CValue<'tcx>,
1000     rhs: CValue<'tcx>,
1001     ret_ty: Ty<'tcx>,
1002 ) -> CValue<'tcx> {
1003     match lhs.layout().ty.sty {
1004         ty::RawPtr(TypeAndMut { ty, mutbl: _ }) => {
1005             if ty.is_sized(fx.tcx.at(DUMMY_SP), ParamEnv::reveal_all()) {
1006                 binop_match! {
1007                     fx, bin_op, false, lhs, rhs, ret_ty, "ptr";
1008                     Add (_) bug;
1009                     Sub (_) bug;
1010                     Mul (_) bug;
1011                     Div (_) bug;
1012                     Rem (_) bug;
1013                     BitXor (_) bug;
1014                     BitAnd (_) bug;
1015                     BitOr (_) bug;
1016                     Shl (_) bug;
1017                     Shr (_) bug;
1018
1019                     Eq (_) icmp(Equal);
1020                     Lt (_) icmp(UnsignedLessThan);
1021                     Le (_) icmp(UnsignedLessThanOrEqual);
1022                     Ne (_) icmp(NotEqual);
1023                     Ge (_) icmp(UnsignedGreaterThanOrEqual);
1024                     Gt (_) icmp(UnsignedGreaterThan);
1025
1026                     Offset (_) iadd;
1027                 }
1028             } else {
1029                 let lhs = lhs.load_value_pair(fx).0;
1030                 let rhs = rhs.load_value_pair(fx).0;
1031                 let res = match bin_op {
1032                     BinOp::Eq => fx.bcx.ins().icmp(IntCC::Equal, lhs, rhs),
1033                     BinOp::Ne => fx.bcx.ins().icmp(IntCC::NotEqual, lhs, rhs),
1034                     _ => unimplemented!(
1035                         "trans_ptr_binop({:?}, <fat ptr>, <fat ptr>) not implemented",
1036                         bin_op
1037                     ),
1038                 };
1039
1040                 assert_eq!(fx.tcx.types.bool, ret_ty);
1041                 let ret_layout = fx.layout_of(ret_ty);
1042                 CValue::ByVal(fx.bcx.ins().bint(types::I8, res), ret_layout)
1043             }
1044         }
1045         _ => bug!("trans_ptr_binop on non ptr"),
1046     }
1047 }
1048
1049 pub fn trans_place<'a, 'tcx: 'a>(
1050     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1051     place: &Place<'tcx>,
1052 ) -> CPlace<'tcx> {
1053     match place {
1054         Place::Local(local) => fx.get_local_place(*local),
1055         Place::Promoted(promoted) => crate::constant::trans_promoted(fx, promoted.0),
1056         Place::Static(static_) => crate::constant::codegen_static_ref(fx, static_),
1057         Place::Projection(projection) => {
1058             let base = trans_place(fx, &projection.base);
1059             match projection.elem {
1060                 ProjectionElem::Deref => base.place_deref(fx),
1061                 ProjectionElem::Field(field, _ty) => base.place_field(fx, field),
1062                 ProjectionElem::Index(local) => {
1063                     let index = fx.get_local_place(local).to_cvalue(fx).load_value(fx);
1064                     base.place_index(fx, index)
1065                 }
1066                 ProjectionElem::ConstantIndex {
1067                     offset,
1068                     min_length: _,
1069                     from_end,
1070                 } => {
1071                     let index = if !from_end {
1072                         fx.bcx.ins().iconst(fx.pointer_type, offset as i64)
1073                     } else {
1074                         let len = codegen_array_len(fx, base);
1075                         fx.bcx.ins().iadd_imm(len, -(offset as i64))
1076                     };
1077                     base.place_index(fx, index)
1078                 }
1079                 ProjectionElem::Subslice { from, to } => unimpl!(
1080                     "projection subslice {:?} from {} to {}",
1081                     projection.base,
1082                     from,
1083                     to
1084                 ),
1085                 ProjectionElem::Downcast(_adt_def, variant) => base.downcast_variant(fx, variant),
1086             }
1087         }
1088     }
1089 }
1090
1091 pub fn trans_operand<'a, 'tcx>(
1092     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1093     operand: &Operand<'tcx>,
1094 ) -> CValue<'tcx> {
1095     match operand {
1096         Operand::Move(place) | Operand::Copy(place) => {
1097             let cplace = trans_place(fx, place);
1098             cplace.to_cvalue(fx)
1099         }
1100         Operand::Constant(const_) => crate::constant::trans_constant(fx, const_),
1101     }
1102 }