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