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 mut fx = FunctionCx {
  86         tcx,
  87         module: cx.module,
  88         pointer_type,
  89
  90         instance,
  91         mir,
  92
  93         bcx,
  94         ebb_map,
  95         local_map: HashMap::new(),
  96
  97         comments: HashMap::new(),
  98         constants: &mut cx.ccx,
  99         caches: &mut cx.caches,
 100
 101         top_nop: None,
 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     let mut writer = crate::pretty_clif::CommentWriter(fx.comments);
 112
 113     let mut clif = String::new();
 114     if cfg!(debug_assertions) {
 115         ::cranelift::codegen::write::decorate_function(&mut writer, &mut clif, &func, None)
 116             .unwrap();
 117         let clif_file_name = format!(
 118             "{}/{}__{}.clif",
 119             concat!(env!("CARGO_MANIFEST_DIR"), "/target/out/clif"),
 120             tcx.crate_name(LOCAL_CRATE),
 121             tcx.symbol_name(instance).as_str(),
 122         );
 123         if let Err(e) = ::std::fs::write(clif_file_name, clif.as_bytes()) {
 124             tcx.sess.warn(&format!("err writing clif file: {:?}", e));
 125         }
 126     }
 127
 128     // Step 8. Verify function
 129     verify_func(tcx, writer, &func);
 130
 131     // Step 9. Define function
 132     cx.caches.context.func = func;
 133     cx.module
 134         .define_function(func_id, &mut cx.caches.context)
 135         .unwrap();
 136     cx.caches.context.clear();
 137 }
 138
 139 fn verify_func(tcx: TyCtxt, writer: crate::pretty_clif::CommentWriter, func: &Function) {
 140     let flags = settings::Flags::new(settings::builder());
 141     match ::cranelift::codegen::verify_function(&func, &flags) {
 142         Ok(_) => {}
 143         Err(err) => {
 144             tcx.sess.err(&format!("{:?}", err));
 145             let pretty_error = ::cranelift::codegen::print_errors::pretty_verifier_error(
 146                 &func,
 147                 None,
 148                 Some(Box::new(writer)),
 149                 err,
 150             );
 151             tcx.sess
 152                 .fatal(&format!("cranelift verify error:\n{}", pretty_error));
 153         }
 154     }
 155 }
 156
 157 fn codegen_fn_content<'a, 'tcx: 'a>(fx: &mut FunctionCx<'a, 'tcx, impl Backend>) {
 158     for (bb, bb_data) in fx.mir.basic_blocks().iter_enumerated() {
 159         if bb_data.is_cleanup {
 160             // Unwinding after panicking is not supported
 161             continue;
 162         }
 163
 164         let ebb = fx.get_ebb(bb);
 165         fx.bcx.switch_to_block(ebb);
 166
 167         fx.bcx.ins().nop();
 168         for stmt in &bb_data.statements {
 169             trans_stmt(fx, ebb, stmt);
 170         }
 171
 172         let mut terminator_head = "\n".to_string();
 173         bb_data
 174             .terminator()
 175             .kind
 176             .fmt_head(&mut terminator_head)
 177             .unwrap();
 178         let inst = fx.bcx.func.layout.last_inst(ebb).unwrap();
 179         fx.add_comment(inst, terminator_head);
 180
 181         match &bb_data.terminator().kind {
 182             TerminatorKind::Goto { target } => {
 183                 let ebb = fx.get_ebb(*target);
 184                 fx.bcx.ins().jump(ebb, &[]);
 185             }
 186             TerminatorKind::Return => {
 187                 crate::abi::codegen_return(fx);
 188             }
 189             TerminatorKind::Assert {
 190                 cond,
 191                 expected,
 192                 msg: _,
 193                 target,
 194                 cleanup: _,
 195             } => {
 196                 let cond = trans_operand(fx, cond).load_value(fx);
 197                 // TODO HACK brz/brnz for i8/i16 is not yet implemented
 198                 let cond = fx.bcx.ins().uextend(types::I32, cond);
 199                 let target = fx.get_ebb(*target);
 200                 if *expected {
 201                     fx.bcx.ins().brnz(cond, target, &[]);
 202                 } else {
 203                     fx.bcx.ins().brz(cond, target, &[]);
 204                 };
 205                 trap_panic(&mut fx.bcx);
 206             }
 207
 208             TerminatorKind::SwitchInt {
 209                 discr,
 210                 switch_ty: _,
 211                 values,
 212                 targets,
 213             } => {
 214                 let discr = trans_operand(fx, discr).load_value(fx);
 215                 let mut switch = ::cranelift::frontend::Switch::new();
 216                 for (i, value) in values.iter().enumerate() {
 217                     let ebb = fx.get_ebb(targets[i]);
 218                     switch.set_entry(*value as u64, ebb);
 219                 }
 220                 let otherwise_ebb = fx.get_ebb(targets[targets.len() - 1]);
 221                 switch.emit(&mut fx.bcx, discr, otherwise_ebb);
 222             }
 223             TerminatorKind::Call {
 224                 func,
 225                 args,
 226                 destination,
 227                 cleanup: _,
 228                 from_hir_call: _,
 229             } => {
 230                 crate::abi::codegen_terminator_call(fx, func, args, destination);
 231             }
 232             TerminatorKind::Resume | TerminatorKind::Abort | TerminatorKind::Unreachable => {
 233                 trap_unreachable(&mut fx.bcx);
 234             }
 235             TerminatorKind::Yield { .. }
 236             | TerminatorKind::FalseEdges { .. }
 237             | TerminatorKind::FalseUnwind { .. }
 238             | TerminatorKind::DropAndReplace { .. } => {
 239                 bug!("shouldn't exist at trans {:?}", bb_data.terminator());
 240             }
 241             TerminatorKind::Drop {
 242                 location,
 243                 target,
 244                 unwind: _,
 245             } => {
 246                 let ty = location.ty(fx.mir, fx.tcx).to_ty(fx.tcx);
 247                 let ty = fx.monomorphize(&ty);
 248                 let drop_fn = crate::rustc_mir::monomorphize::resolve_drop_in_place(fx.tcx, ty);
 249
 250                 if let ty::InstanceDef::DropGlue(_, None) = drop_fn.def {
 251                     // we don't actually need to drop anything
 252                 } else {
 253                     let drop_place = trans_place(fx, location);
 254                     let arg_place = CPlace::temp(
 255                         fx,
 256                         fx.tcx.mk_ref(
 257                             &ty::RegionKind::ReErased,
 258                             TypeAndMut {
 259                                 ty,
 260                                 mutbl: crate::rustc::hir::Mutability::MutMutable,
 261                             },
 262                         ),
 263                     );
 264                     drop_place.write_place_ref(fx, arg_place);
 265                     match ty.sty {
 266                         ty::Dynamic(..) => {
 267                             fx.tcx.sess.warn("Drop for trait object");
 268                         }
 269                         _ => {
 270                             let drop_fn_ty = drop_fn.ty(fx.tcx);
 271                             let arg_value = arg_place.to_cvalue(fx);
 272                             crate::abi::codegen_call_inner(
 273                                 fx,
 274                                 None,
 275                                 drop_fn_ty,
 276                                 vec![arg_value],
 277                                 None,
 278                             );
 279                         }
 280                     }
 281                     /*
 282                     let (args1, args2);
 283                     /*let mut args = if let Some(llextra) = place.llextra {
 284                         args2 = [place.llval, llextra];
 285                         &args2[..]
 286                     } else {
 287                         args1 = [place.llval];
 288                         &args1[..]
 289                     };*/
 290                     let (drop_fn, fn_ty) = match ty.sty {
 291                     ty::Dynamic(..) => {
 292                     let fn_ty = drop_fn.ty(bx.cx.tcx);
 293                     let sig = common::ty_fn_sig(bx.cx, fn_ty);
 294                     let sig = bx.tcx().normalize_erasing_late_bound_regions(
 295                     ty::ParamEnv::reveal_all(),
 296                     &sig,
 297                     );
 298                     let fn_ty = FnType::new_vtable(bx.cx, sig, &[]);
 299                     let vtable = args[1];
 300                     args = &args[..1];
 301                     (meth::DESTRUCTOR.get_fn(&bx, vtable, &fn_ty), fn_ty)
 302                     }
 303                     _ => {
 304                     let value = place.to_cvalue(fx);
 305                     (callee::get_fn(bx.cx, drop_fn),
 306                     FnType::of_instance(bx.cx, &drop_fn))
 307                     }
 308                     };
 309                     do_call(self, bx, fn_ty, drop_fn, args,
 310                     Some((ReturnDest::Nothing, target)),
 311                     unwind);*/
 312                 }
 313
 314                 let target_ebb = fx.get_ebb(*target);
 315                 fx.bcx.ins().jump(target_ebb, &[]);
 316             }
 317             TerminatorKind::GeneratorDrop => {
 318                 unimplemented!("terminator GeneratorDrop");
 319             }
 320         };
 321     }
 322
 323     fx.bcx.seal_all_blocks();
 324     fx.bcx.finalize();
 325 }
 326
 327 fn trans_stmt<'a, 'tcx: 'a>(
 328     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 329     cur_ebb: Ebb,
 330     stmt: &Statement<'tcx>,
 331 ) {
 332     let _print_guard = PrintOnPanic(|| format!("stmt {:?}", stmt));
 333
 334     match &stmt.kind {
 335         StatementKind::StorageLive(..) | StatementKind::StorageDead(..) => {} // Those are not very useful
 336         _ => {
 337             let inst = fx.bcx.func.layout.last_inst(cur_ebb).unwrap();
 338             fx.add_comment(inst, format!("{:?}", stmt));
 339         }
 340     }
 341
 342     match &stmt.kind {
 343         StatementKind::SetDiscriminant {
 344             place,
 345             variant_index,
 346         } => {
 347             let place = trans_place(fx, place);
 348             let layout = place.layout();
 349             if layout.for_variant(&*fx, *variant_index).abi == layout::Abi::Uninhabited {
 350                 return;
 351             }
 352             match layout.variants {
 353                 layout::Variants::Single { index } => {
 354                     assert_eq!(index, *variant_index);
 355                 }
 356                 layout::Variants::Tagged { .. } => {
 357                     let ptr = place.place_field(fx, mir::Field::new(0));
 358                     let to = layout
 359                         .ty
 360                         .ty_adt_def()
 361                         .unwrap()
 362                         .discriminant_for_variant(fx.tcx, *variant_index)
 363                         .val;
 364                     let discr = CValue::const_val(fx, ptr.layout().ty, to as u64 as i64);
 365                     ptr.write_cvalue(fx, discr);
 366                 }
 367                 layout::Variants::NicheFilling {
 368                     dataful_variant,
 369                     ref niche_variants,
 370                     niche_start,
 371                     ..
 372                 } => {
 373                     if *variant_index != dataful_variant {
 374                         let niche = place.place_field(fx, mir::Field::new(0));
 375                         //let niche_llty = niche.layout.immediate_llvm_type(bx.cx);
 376                         let niche_value =
 377                             ((variant_index.as_u32() - niche_variants.start().as_u32()) as u128)
 378                                 .wrapping_add(niche_start);
 379                         // FIXME(eddyb) Check the actual primitive type here.
 380                         let niche_llval = if niche_value == 0 {
 381                             CValue::const_val(fx, niche.layout().ty, 0)
 382                         } else {
 383                             CValue::const_val(fx, niche.layout().ty, niche_value as u64 as i64)
 384                         };
 385                         niche.write_cvalue(fx, niche_llval);
 386                     }
 387                 }
 388             }
 389         }
 390         StatementKind::Assign(to_place, rval) => {
 391             let lval = trans_place(fx, to_place);
 392             let dest_layout = lval.layout();
 393             match &**rval {
 394                 Rvalue::Use(operand) => {
 395                     let val = trans_operand(fx, operand);
 396                     lval.write_cvalue(fx, val);
 397                 }
 398                 Rvalue::Ref(_, _, place) => {
 399                     let place = trans_place(fx, place);
 400                     place.write_place_ref(fx, lval);
 401                 }
 402                 Rvalue::BinaryOp(bin_op, lhs, rhs) => {
 403                     let ty = fx.monomorphize(&lhs.ty(fx.mir, fx.tcx));
 404                     let lhs = trans_operand(fx, lhs);
 405                     let rhs = trans_operand(fx, rhs);
 406
 407                     let res = match ty.sty {
 408                         ty::Bool => trans_bool_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 409                         ty::Uint(_) => {
 410                             trans_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, false)
 411                         }
 412                         ty::Int(_) => {
 413                             trans_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, true)
 414                         }
 415                         ty::Float(_) => trans_float_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 416                         ty::Char => trans_char_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 417                         ty::RawPtr(..) => trans_ptr_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 418                         _ => unimplemented!("binop {:?} for {:?}", bin_op, ty),
 419                     };
 420                     lval.write_cvalue(fx, res);
 421                 }
 422                 Rvalue::CheckedBinaryOp(bin_op, lhs, rhs) => {
 423                     let ty = fx.monomorphize(&lhs.ty(fx.mir, fx.tcx));
 424                     let lhs = trans_operand(fx, lhs);
 425                     let rhs = trans_operand(fx, rhs);
 426
 427                     let res = match ty.sty {
 428                         ty::Uint(_) => {
 429                             trans_checked_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, false)
 430                         }
 431                         ty::Int(_) => {
 432                             trans_checked_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, true)
 433                         }
 434                         _ => unimplemented!("checked binop {:?} for {:?}", bin_op, ty),
 435                     };
 436                     lval.write_cvalue(fx, res);
 437                 }
 438                 Rvalue::UnaryOp(un_op, operand) => {
 439                     let operand = trans_operand(fx, operand);
 440                     let layout = operand.layout();
 441                     let val = operand.load_value(fx);
 442                     let res = match un_op {
 443                         UnOp::Not => {
 444                             match layout.ty.sty {
 445                                 ty::Bool => {
 446                                     let val = fx.bcx.ins().uextend(types::I32, val); // WORKAROUND for CraneStation/cranelift#466
 447                                     let res = fx.bcx.ins().icmp_imm(IntCC::Equal, val, 0);
 448                                     fx.bcx.ins().bint(types::I8, res)
 449                                 }
 450                                 ty::Uint(_) | ty::Int(_) => fx.bcx.ins().bnot(val),
 451                                 _ => unimplemented!("un op Not for {:?}", layout.ty),
 452                             }
 453                         }
 454                         UnOp::Neg => match layout.ty.sty {
 455                             ty::Int(_) => {
 456                                 let clif_ty = fx.clif_type(layout.ty).unwrap();
 457                                 let zero = fx.bcx.ins().iconst(clif_ty, 0);
 458                                 fx.bcx.ins().isub(zero, val)
 459                             }
 460                             ty::Float(_) => fx.bcx.ins().fneg(val),
 461                             _ => unimplemented!("un op Neg for {:?}", layout.ty),
 462                         },
 463                     };
 464                     lval.write_cvalue(fx, CValue::ByVal(res, layout));
 465                 }
 466                 Rvalue::Cast(CastKind::ReifyFnPointer, operand, ty) => {
 467                     let operand = trans_operand(fx, operand);
 468                     let layout = fx.layout_of(ty);
 469                     lval.write_cvalue(fx, operand.unchecked_cast_to(layout));
 470                 }
 471                 Rvalue::Cast(CastKind::UnsafeFnPointer, operand, ty) => {
 472                     let operand = trans_operand(fx, operand);
 473                     let layout = fx.layout_of(ty);
 474                     lval.write_cvalue(fx, operand.unchecked_cast_to(layout));
 475                 }
 476                 Rvalue::Cast(CastKind::Misc, operand, to_ty) => {
 477                     let operand = trans_operand(fx, operand);
 478                     let from_ty = operand.layout().ty;
 479                     match (&from_ty.sty, &to_ty.sty) {
 480                         (ty::Ref(..), ty::Ref(..))
 481                         | (ty::Ref(..), ty::RawPtr(..))
 482                         | (ty::RawPtr(..), ty::Ref(..))
 483                         | (ty::RawPtr(..), ty::RawPtr(..))
 484                         | (ty::FnPtr(..), ty::RawPtr(..)) => {
 485                             lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
 486                         }
 487                         (ty::RawPtr(..), ty::Uint(_))
 488                         | (ty::RawPtr(..), ty::Int(_))
 489                         | (ty::FnPtr(..), ty::Uint(_))
 490                             if to_ty.sty == fx.tcx.types.usize.sty
 491                                 || to_ty.sty == fx.tcx.types.isize.sty
 492                                 || fx.clif_type(to_ty).unwrap() == pointer_ty(fx.tcx) =>
 493                         {
 494                             lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
 495                         }
 496                         (ty::Uint(_), ty::RawPtr(..)) if from_ty.sty == fx.tcx.types.usize.sty => {
 497                             lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
 498                         }
 499                         (ty::Char, ty::Uint(_))
 500                         | (ty::Uint(_), ty::Char)
 501                         | (ty::Uint(_), ty::Int(_))
 502                         | (ty::Uint(_), ty::Uint(_)) => {
 503                             let from = operand.load_value(fx);
 504                             let res = crate::common::clif_intcast(
 505                                 fx,
 506                                 from,
 507                                 fx.clif_type(to_ty).unwrap(),
 508                                 false,
 509                             );
 510                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 511                         }
 512                         (ty::Int(_), ty::Int(_)) | (ty::Int(_), ty::Uint(_)) => {
 513                             let from = operand.load_value(fx);
 514                             let res = crate::common::clif_intcast(
 515                                 fx,
 516                                 from,
 517                                 fx.clif_type(to_ty).unwrap(),
 518                                 true,
 519                             );
 520                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 521                         }
 522                         (ty::Float(from_flt), ty::Float(to_flt)) => {
 523                             let from = operand.load_value(fx);
 524                             let res = match (from_flt, to_flt) {
 525                                 (FloatTy::F32, FloatTy::F64) => {
 526                                     fx.bcx.ins().fpromote(types::F64, from)
 527                                 }
 528                                 (FloatTy::F64, FloatTy::F32) => {
 529                                     fx.bcx.ins().fdemote(types::F32, from)
 530                                 }
 531                                 _ => from,
 532                             };
 533                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 534                         }
 535                         (ty::Int(_), 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_sint.f32.i8
 539                             let from = if from_ty == types::I8 || from_ty == types::I16 {
 540                                 fx.bcx.ins().sextend(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_sint(f_type, from);
 546                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 547                         }
 548                         (ty::Uint(_), ty::Float(_)) => {
 549                             let from_ty = fx.clif_type(from_ty).unwrap();
 550                             let from = operand.load_value(fx);
 551                             // FIXME missing encoding for fcvt_from_uint.f32.i8
 552                             let from = if from_ty == types::I8 || from_ty == types::I16 {
 553                                 fx.bcx.ins().uextend(types::I32, from)
 554                             } else {
 555                                 from
 556                             };
 557                             let f_type = fx.clif_type(to_ty).unwrap();
 558                             let res = fx.bcx.ins().fcvt_from_uint(f_type, from);
 559                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 560                         }
 561                         (ty::Bool, ty::Uint(_)) | (ty::Bool, ty::Int(_)) => {
 562                             let to_ty = fx.clif_type(to_ty).unwrap();
 563                             let from = operand.load_value(fx);
 564                             let res = if to_ty != types::I8 {
 565                                 fx.bcx.ins().uextend(to_ty, from)
 566                             } else {
 567                                 from
 568                             };
 569                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 570                         }
 571                         (ty::Adt(adt_def, _substs), ty::Uint(_)) | (ty::Adt(adt_def, _substs), ty::Int(_)) if adt_def.is_enum() => {
 572                             let discr = trans_get_discriminant(fx, operand, fx.layout_of(to_ty));
 573                             lval.write_cvalue(fx, discr);
 574                         }
 575                         _ => unimpl!("rval misc {:?} {:?}", from_ty, to_ty),
 576                     }
 577                 }
 578                 Rvalue::Cast(CastKind::ClosureFnPointer, operand, ty) => {
 579                     unimplemented!("rval closure_fn_ptr {:?} {:?}", operand, ty)
 580                 }
 581                 Rvalue::Cast(CastKind::Unsize, operand, _ty) => {
 582                     let operand = trans_operand(fx, operand);
 583                     operand.unsize_value(fx, lval);
 584                 }
 585                 Rvalue::Discriminant(place) => {
 586                     let place = trans_place(fx, place).to_cvalue(fx);
 587                     let discr = trans_get_discriminant(fx, place, dest_layout);
 588                     lval.write_cvalue(fx, discr);
 589                 }
 590                 Rvalue::Repeat(operand, times) => {
 591                     let operand = trans_operand(fx, operand);
 592                     for i in 0..*times {
 593                         let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
 594                         let to = lval.place_index(fx, index);
 595                         to.write_cvalue(fx, operand);
 596                     }
 597                 }
 598                 Rvalue::Len(place) => {
 599                     let place = trans_place(fx, place);
 600                     let usize_layout = fx.layout_of(fx.tcx.types.usize);
 601                     let len = codegen_array_len(fx, place);
 602                     lval.write_cvalue(fx, CValue::ByVal(len, usize_layout));
 603                 }
 604                 Rvalue::NullaryOp(NullOp::Box, content_ty) => {
 605                     use rustc::middle::lang_items::ExchangeMallocFnLangItem;
 606
 607                     let usize_type = fx.clif_type(fx.tcx.types.usize).unwrap();
 608                     let layout = fx.layout_of(content_ty);
 609                     let llsize = fx.bcx.ins().iconst(usize_type, layout.size.bytes() as i64);
 610                     let llalign = fx
 611                         .bcx
 612                         .ins()
 613                         .iconst(usize_type, layout.align.abi.bytes() as i64);
 614                     let box_layout = fx.layout_of(fx.tcx.mk_box(content_ty));
 615
 616                     // Allocate space:
 617                     let def_id = match fx.tcx.lang_items().require(ExchangeMallocFnLangItem) {
 618                         Ok(id) => id,
 619                         Err(s) => {
 620                             fx.tcx
 621                                 .sess
 622                                 .fatal(&format!("allocation of `{}` {}", box_layout.ty, s));
 623                         }
 624                     };
 625                     let instance = ty::Instance::mono(fx.tcx, def_id);
 626                     let func_ref = fx.get_function_ref(instance);
 627                     let call = fx.bcx.ins().call(func_ref, &[llsize, llalign]);
 628                     let ptr = fx.bcx.inst_results(call)[0];
 629                     lval.write_cvalue(fx, CValue::ByVal(ptr, box_layout));
 630                 }
 631                 Rvalue::NullaryOp(NullOp::SizeOf, ty) => {
 632                     assert!(lval
 633                         .layout()
 634                         .ty
 635                         .is_sized(fx.tcx.at(DUMMY_SP), ParamEnv::reveal_all()));
 636                     let ty_size = fx.layout_of(ty).size.bytes();
 637                     let val = CValue::const_val(fx, fx.tcx.types.usize, ty_size as i64);
 638                     lval.write_cvalue(fx, val);
 639                 }
 640                 Rvalue::Aggregate(kind, operands) => match **kind {
 641                     AggregateKind::Array(_ty) => {
 642                         for (i, operand) in operands.into_iter().enumerate() {
 643                             let operand = trans_operand(fx, operand);
 644                             let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
 645                             let to = lval.place_index(fx, index);
 646                             to.write_cvalue(fx, operand);
 647                         }
 648                     }
 649                     _ => unimpl!("shouldn't exist at trans {:?}", rval),
 650                 },
 651             }
 652         }
 653         StatementKind::StorageLive(_)
 654         | StatementKind::StorageDead(_)
 655         | StatementKind::Nop
 656         | StatementKind::FakeRead(..)
 657         | StatementKind::Retag { .. }
 658         | StatementKind::AscribeUserType(..) => {}
 659
 660         StatementKind::InlineAsm { .. } => unimpl!("Inline assembly is not supported"),
 661     }
 662 }
 663
 664 fn codegen_array_len<'a, 'tcx: 'a>(
 665     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 666     place: CPlace<'tcx>,
 667 ) -> Value {
 668     match place.layout().ty.sty {
 669         ty::Array(_elem_ty, len) => {
 670             let len = crate::constant::force_eval_const(fx, len).unwrap_usize(fx.tcx) as i64;
 671             fx.bcx.ins().iconst(fx.pointer_type, len)
 672         }
 673         ty::Slice(_elem_ty) => match place {
 674             CPlace::Addr(_, size, _) => size.unwrap(),
 675             CPlace::Var(_, _) => unreachable!(),
 676         },
 677         _ => bug!("Rvalue::Len({:?})", place),
 678     }
 679 }
 680
 681 pub fn trans_get_discriminant<'a, 'tcx: 'a>(
 682     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 683     value: CValue<'tcx>,
 684     dest_layout: TyLayout<'tcx>,
 685 ) -> CValue<'tcx> {
 686     let layout = value.layout();
 687
 688     if layout.abi == layout::Abi::Uninhabited {
 689         trap_unreachable(&mut fx.bcx);
 690     }
 691     match layout.variants {
 692         layout::Variants::Single { index } => {
 693             let discr_val = layout
 694                 .ty
 695                 .ty_adt_def()
 696                 .map_or(index.as_u32() as u128, |def| {
 697                     def.discriminant_for_variant(fx.tcx, index).val
 698                 });
 699             return CValue::const_val(fx, dest_layout.ty, discr_val as u64 as i64);
 700         }
 701         layout::Variants::Tagged { .. } | layout::Variants::NicheFilling { .. } => {}
 702     }
 703
 704     let discr = value.value_field(fx, mir::Field::new(0));
 705     let discr_ty = discr.layout().ty;
 706     let lldiscr = discr.load_value(fx);
 707     match layout.variants {
 708         layout::Variants::Single { .. } => bug!(),
 709         layout::Variants::Tagged { ref tag, .. } => {
 710             let signed = match tag.value {
 711                 layout::Int(_, signed) => signed,
 712                 _ => false,
 713             };
 714             let val = clif_intcast(fx, lldiscr, fx.clif_type(dest_layout.ty).unwrap(), signed);
 715             return CValue::ByVal(val, dest_layout);
 716         }
 717         layout::Variants::NicheFilling {
 718             dataful_variant,
 719             ref niche_variants,
 720             niche_start,
 721             ..
 722         } => {
 723             let niche_llty = fx.clif_type(discr_ty).unwrap();
 724             let dest_clif_ty = fx.clif_type(dest_layout.ty).unwrap();
 725             if niche_variants.start() == niche_variants.end() {
 726                 let b = fx
 727                     .bcx
 728                     .ins()
 729                     .icmp_imm(IntCC::Equal, lldiscr, niche_start as u64 as i64);
 730                 let if_true = fx
 731                     .bcx
 732                     .ins()
 733                     .iconst(dest_clif_ty, niche_variants.start().as_u32() as i64);
 734                 let if_false = fx
 735                     .bcx
 736                     .ins()
 737                     .iconst(dest_clif_ty, dataful_variant.as_u32() as i64);
 738                 let val = fx.bcx.ins().select(b, if_true, if_false);
 739                 return CValue::ByVal(val, dest_layout);
 740             } else {
 741                 // Rebase from niche values to discriminant values.
 742                 let delta = niche_start.wrapping_sub(niche_variants.start().as_u32() as u128);
 743                 let delta = fx.bcx.ins().iconst(niche_llty, delta as u64 as i64);
 744                 let lldiscr = fx.bcx.ins().isub(lldiscr, delta);
 745                 let b = fx.bcx.ins().icmp_imm(
 746                     IntCC::UnsignedLessThanOrEqual,
 747                     lldiscr,
 748                     niche_variants.end().as_u32() as i64,
 749                 );
 750                 let if_true =
 751                     clif_intcast(fx, lldiscr, fx.clif_type(dest_layout.ty).unwrap(), false);
 752                 let if_false = fx
 753                     .bcx
 754                     .ins()
 755                     .iconst(dest_clif_ty, dataful_variant.as_u32() as i64);
 756                 let val = fx.bcx.ins().select(b, if_true, if_false);
 757                 return CValue::ByVal(val, dest_layout);
 758             }
 759         }
 760     }
 761 }
 762
 763 macro_rules! binop_match {
 764     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, bug) => {
 765         bug!("binop {} on {} lhs: {:?} rhs: {:?}", stringify!($var), $bug_fmt, $lhs, $rhs)
 766     };
 767     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, icmp($cc:ident)) => {{
 768         assert_eq!($fx.tcx.types.bool, $ret_ty);
 769         let ret_layout = $fx.layout_of($ret_ty);
 770
 771         let b = $fx.bcx.ins().icmp(IntCC::$cc, $lhs, $rhs);
 772         CValue::ByVal($fx.bcx.ins().bint(types::I8, b), ret_layout)
 773     }};
 774     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, fcmp($cc:ident)) => {{
 775         assert_eq!($fx.tcx.types.bool, $ret_ty);
 776         let ret_layout = $fx.layout_of($ret_ty);
 777         let b = $fx.bcx.ins().fcmp(FloatCC::$cc, $lhs, $rhs);
 778         CValue::ByVal($fx.bcx.ins().bint(types::I8, b), ret_layout)
 779     }};
 780     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, custom(|| $body:expr)) => {{
 781         $body
 782     }};
 783     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, $name:ident) => {{
 784         let ret_layout = $fx.layout_of($ret_ty);
 785         CValue::ByVal($fx.bcx.ins().$name($lhs, $rhs), ret_layout)
 786     }};
 787     (
 788         $fx:expr, $bin_op:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, $bug_fmt:expr;
 789         $(
 790             $var:ident ($sign:pat) $name:tt $( ( $($next:tt)* ) )? ;
 791         )*
 792     ) => {{
 793         let lhs = $lhs.load_value($fx);
 794         let rhs = $rhs.load_value($fx);
 795         match ($bin_op, $signed) {
 796             $(
 797                 (BinOp::$var, $sign) => binop_match!(@single $fx, $bug_fmt, $var, $signed, lhs, rhs, $ret_ty, $name $( ( $($next)* ) )?),
 798             )*
 799         }
 800     }}
 801 }
 802
 803 fn trans_bool_binop<'a, 'tcx: 'a>(
 804     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 805     bin_op: BinOp,
 806     lhs: CValue<'tcx>,
 807     rhs: CValue<'tcx>,
 808     ty: Ty<'tcx>,
 809 ) -> CValue<'tcx> {
 810     let res = binop_match! {
 811         fx, bin_op, false, lhs, rhs, ty, "bool";
 812         Add (_) bug;
 813         Sub (_) bug;
 814         Mul (_) bug;
 815         Div (_) bug;
 816         Rem (_) bug;
 817         BitXor (_) bxor;
 818         BitAnd (_) band;
 819         BitOr (_) bor;
 820         Shl (_) bug;
 821         Shr (_) bug;
 822
 823         Eq (_) icmp(Equal);
 824         Lt (_) icmp(UnsignedLessThan);
 825         Le (_) icmp(UnsignedLessThanOrEqual);
 826         Ne (_) icmp(NotEqual);
 827         Ge (_) icmp(UnsignedGreaterThanOrEqual);
 828         Gt (_) icmp(UnsignedGreaterThan);
 829
 830         Offset (_) bug;
 831     };
 832
 833     res
 834 }
 835
 836 pub fn trans_int_binop<'a, 'tcx: 'a>(
 837     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 838     bin_op: BinOp,
 839     lhs: CValue<'tcx>,
 840     rhs: CValue<'tcx>,
 841     out_ty: Ty<'tcx>,
 842     signed: bool,
 843 ) -> CValue<'tcx> {
 844     if bin_op != BinOp::Shl && bin_op != BinOp::Shr {
 845         assert_eq!(
 846             lhs.layout().ty,
 847             rhs.layout().ty,
 848             "int binop requires lhs and rhs of same type"
 849         );
 850     }
 851     binop_match! {
 852         fx, bin_op, signed, lhs, rhs, out_ty, "int/uint";
 853         Add (_) iadd;
 854         Sub (_) isub;
 855         Mul (_) imul;
 856         Div (false) udiv;
 857         Div (true) sdiv;
 858         Rem (false) urem;
 859         Rem (true) srem;
 860         BitXor (_) bxor;
 861         BitAnd (_) band;
 862         BitOr (_) bor;
 863         Shl (_) ishl;
 864         Shr (false) ushr;
 865         Shr (true) sshr;
 866
 867         Eq (_) icmp(Equal);
 868         Lt (false) icmp(UnsignedLessThan);
 869         Lt (true) icmp(SignedLessThan);
 870         Le (false) icmp(UnsignedLessThanOrEqual);
 871         Le (true) icmp(SignedLessThanOrEqual);
 872         Ne (_) icmp(NotEqual);
 873         Ge (false) icmp(UnsignedGreaterThanOrEqual);
 874         Ge (true) icmp(SignedGreaterThanOrEqual);
 875         Gt (false) icmp(UnsignedGreaterThan);
 876         Gt (true) icmp(SignedGreaterThan);
 877
 878         Offset (_) bug;
 879     }
 880 }
 881
 882 pub fn trans_checked_int_binop<'a, 'tcx: 'a>(
 883     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 884     bin_op: BinOp,
 885     in_lhs: CValue<'tcx>,
 886     in_rhs: CValue<'tcx>,
 887     out_ty: Ty<'tcx>,
 888     signed: bool,
 889 ) -> CValue<'tcx> {
 890     if bin_op != BinOp::Shl && bin_op != BinOp::Shr {
 891         assert_eq!(
 892             in_lhs.layout().ty,
 893             in_rhs.layout().ty,
 894             "checked int binop requires lhs and rhs of same type"
 895         );
 896     }
 897
 898     let lhs = in_lhs.load_value(fx);
 899     let rhs = in_rhs.load_value(fx);
 900     let res = match bin_op {
 901         BinOp::Add => fx.bcx.ins().iadd(lhs, rhs),
 902         BinOp::Sub => fx.bcx.ins().isub(lhs, rhs),
 903         BinOp::Mul => fx.bcx.ins().imul(lhs, rhs),
 904         BinOp::Shl => fx.bcx.ins().ishl(lhs, rhs),
 905         BinOp::Shr => {
 906             if !signed {
 907                 fx.bcx.ins().ushr(lhs, rhs)
 908             } else {
 909                 fx.bcx.ins().sshr(lhs, rhs)
 910             }
 911         }
 912         _ => bug!(
 913             "binop {:?} on checked int/uint lhs: {:?} rhs: {:?}",
 914             bin_op,
 915             in_lhs,
 916             in_rhs
 917         ),
 918     };
 919
 920     // TODO: check for overflow
 921     let has_overflow = fx.bcx.ins().iconst(types::I8, 0);
 922
 923     let out_place = CPlace::temp(fx, out_ty);
 924     let out_layout = out_place.layout();
 925     out_place.write_cvalue(fx, CValue::ByValPair(res, has_overflow, out_layout));
 926
 927     out_place.to_cvalue(fx)
 928 }
 929
 930 fn trans_float_binop<'a, 'tcx: 'a>(
 931     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 932     bin_op: BinOp,
 933     lhs: CValue<'tcx>,
 934     rhs: CValue<'tcx>,
 935     ty: Ty<'tcx>,
 936 ) -> CValue<'tcx> {
 937     let res = binop_match! {
 938         fx, bin_op, false, lhs, rhs, ty, "float";
 939         Add (_) fadd;
 940         Sub (_) fsub;
 941         Mul (_) fmul;
 942         Div (_) fdiv;
 943         Rem (_) custom(|| {
 944             assert_eq!(lhs.layout().ty, ty);
 945             assert_eq!(rhs.layout().ty, ty);
 946             match ty.sty {
 947                 ty::Float(FloatTy::F32) => fx.easy_call("fmodf", &[lhs, rhs], ty),
 948                 ty::Float(FloatTy::F64) => fx.easy_call("fmod", &[lhs, rhs], ty),
 949                 _ => bug!(),
 950             }
 951         });
 952         BitXor (_) bxor;
 953         BitAnd (_) band;
 954         BitOr (_) bor;
 955         Shl (_) bug;
 956         Shr (_) bug;
 957
 958         Eq (_) fcmp(Equal);
 959         Lt (_) fcmp(LessThan);
 960         Le (_) fcmp(LessThanOrEqual);
 961         Ne (_) fcmp(NotEqual);
 962         Ge (_) fcmp(GreaterThanOrEqual);
 963         Gt (_) fcmp(GreaterThan);
 964
 965         Offset (_) bug;
 966     };
 967
 968     res
 969 }
 970
 971 fn trans_char_binop<'a, 'tcx: 'a>(
 972     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 973     bin_op: BinOp,
 974     lhs: CValue<'tcx>,
 975     rhs: CValue<'tcx>,
 976     ty: Ty<'tcx>,
 977 ) -> CValue<'tcx> {
 978     let res = binop_match! {
 979         fx, bin_op, false, lhs, rhs, ty, "char";
 980         Add (_) bug;
 981         Sub (_) bug;
 982         Mul (_) bug;
 983         Div (_) bug;
 984         Rem (_) bug;
 985         BitXor (_) bug;
 986         BitAnd (_) bug;
 987         BitOr (_) bug;
 988         Shl (_) bug;
 989         Shr (_) bug;
 990
 991         Eq (_) icmp(Equal);
 992         Lt (_) icmp(UnsignedLessThan);
 993         Le (_) icmp(UnsignedLessThanOrEqual);
 994         Ne (_) icmp(NotEqual);
 995         Ge (_) icmp(UnsignedGreaterThanOrEqual);
 996         Gt (_) icmp(UnsignedGreaterThan);
 997
 998         Offset (_) bug;
 999     };
1000
1001     res
1002 }
1003
1004 fn trans_ptr_binop<'a, 'tcx: 'a>(
1005     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1006     bin_op: BinOp,
1007     lhs: CValue<'tcx>,
1008     rhs: CValue<'tcx>,
1009     ret_ty: Ty<'tcx>,
1010 ) -> CValue<'tcx> {
1011     match lhs.layout().ty.sty {
1012         ty::RawPtr(TypeAndMut { ty, mutbl: _ }) => {
1013             if ty.is_sized(fx.tcx.at(DUMMY_SP), ParamEnv::reveal_all()) {
1014                 binop_match! {
1015                     fx, bin_op, false, lhs, rhs, ret_ty, "ptr";
1016                     Add (_) bug;
1017                     Sub (_) bug;
1018                     Mul (_) bug;
1019                     Div (_) bug;
1020                     Rem (_) bug;
1021                     BitXor (_) bug;
1022                     BitAnd (_) bug;
1023                     BitOr (_) bug;
1024                     Shl (_) bug;
1025                     Shr (_) bug;
1026
1027                     Eq (_) icmp(Equal);
1028                     Lt (_) icmp(UnsignedLessThan);
1029                     Le (_) icmp(UnsignedLessThanOrEqual);
1030                     Ne (_) icmp(NotEqual);
1031                     Ge (_) icmp(UnsignedGreaterThanOrEqual);
1032                     Gt (_) icmp(UnsignedGreaterThan);
1033
1034                     Offset (_) iadd;
1035                 }
1036             } else {
1037                 let lhs = lhs.load_value_pair(fx).0;
1038                 let rhs = rhs.load_value_pair(fx).0;
1039                 let res = match bin_op {
1040                     BinOp::Eq => fx.bcx.ins().icmp(IntCC::Equal, lhs, rhs),
1041                     BinOp::Ne => fx.bcx.ins().icmp(IntCC::NotEqual, lhs, rhs),
1042                     _ => unimplemented!(
1043                         "trans_ptr_binop({:?}, <fat ptr>, <fat ptr>) not implemented",
1044                         bin_op
1045                     ),
1046                 };
1047
1048                 assert_eq!(fx.tcx.types.bool, ret_ty);
1049                 let ret_layout = fx.layout_of(ret_ty);
1050                 CValue::ByVal(fx.bcx.ins().bint(types::I8, res), ret_layout)
1051             }
1052         }
1053         _ => bug!("trans_ptr_binop on non ptr"),
1054     }
1055 }
1056
1057 pub fn trans_place<'a, 'tcx: 'a>(
1058     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1059     place: &Place<'tcx>,
1060 ) -> CPlace<'tcx> {
1061     match place {
1062         Place::Local(local) => fx.get_local_place(*local),
1063         Place::Promoted(promoted) => crate::constant::trans_promoted(fx, promoted.0),
1064         Place::Static(static_) => crate::constant::codegen_static_ref(fx, static_),
1065         Place::Projection(projection) => {
1066             let base = trans_place(fx, &projection.base);
1067             match projection.elem {
1068                 ProjectionElem::Deref => base.place_deref(fx),
1069                 ProjectionElem::Field(field, _ty) => base.place_field(fx, field),
1070                 ProjectionElem::Index(local) => {
1071                     let index = fx.get_local_place(local).to_cvalue(fx).load_value(fx);
1072                     base.place_index(fx, index)
1073                 }
1074                 ProjectionElem::ConstantIndex {
1075                     offset,
1076                     min_length: _,
1077                     from_end,
1078                 } => {
1079                     let index = if !from_end {
1080                         fx.bcx.ins().iconst(fx.pointer_type, offset as i64)
1081                     } else {
1082                         let len = codegen_array_len(fx, base);
1083                         fx.bcx.ins().iadd_imm(len, -(offset as i64))
1084                     };
1085                     base.place_index(fx, index)
1086                 }
1087                 ProjectionElem::Subslice { from, to } => unimpl!(
1088                     "projection subslice {:?} from {} to {}",
1089                     projection.base,
1090                     from,
1091                     to
1092                 ),
1093                 ProjectionElem::Downcast(_adt_def, variant) => base.downcast_variant(fx, variant),
1094             }
1095         }
1096     }
1097 }
1098
1099 pub fn trans_operand<'a, 'tcx>(
1100     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1101     operand: &Operand<'tcx>,
1102 ) -> CValue<'tcx> {
1103     match operand {
1104         Operand::Move(place) | Operand::Copy(place) => {
1105             let cplace = trans_place(fx, place);
1106             cplace.to_cvalue(fx)
1107         }
1108         Operand::Constant(const_) => crate::constant::trans_constant(fx, const_),
1109     }
1110 }