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                         ty::FnPtr(..) => trans_ptr_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 396                         _ => unimplemented!("binop {:?} for {:?}", bin_op, ty),
 397                     };
 398                     lval.write_cvalue(fx, res);
 399                 }
 400                 Rvalue::CheckedBinaryOp(bin_op, lhs, rhs) => {
 401                     let ty = fx.monomorphize(&lhs.ty(fx.mir, fx.tcx));
 402                     let lhs = trans_operand(fx, lhs);
 403                     let rhs = trans_operand(fx, rhs);
 404
 405                     let res = match ty.sty {
 406                         ty::Uint(_) => {
 407                             trans_checked_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, false)
 408                         }
 409                         ty::Int(_) => {
 410                             trans_checked_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, true)
 411                         }
 412                         _ => unimplemented!("checked binop {:?} for {:?}", bin_op, ty),
 413                     };
 414                     lval.write_cvalue(fx, res);
 415                 }
 416                 Rvalue::UnaryOp(un_op, operand) => {
 417                     let operand = trans_operand(fx, operand);
 418                     let layout = operand.layout();
 419                     let val = operand.load_scalar(fx);
 420                     let res = match un_op {
 421                         UnOp::Not => {
 422                             match layout.ty.sty {
 423                                 ty::Bool => {
 424                                     let val = fx.bcx.ins().uextend(types::I32, val); // WORKAROUND for CraneStation/cranelift#466
 425                                     let res = fx.bcx.ins().icmp_imm(IntCC::Equal, val, 0);
 426                                     fx.bcx.ins().bint(types::I8, res)
 427                                 }
 428                                 ty::Uint(_) | ty::Int(_) => fx.bcx.ins().bnot(val),
 429                                 _ => unimplemented!("un op Not for {:?}", layout.ty),
 430                             }
 431                         }
 432                         UnOp::Neg => match layout.ty.sty {
 433                             ty::Int(_) => {
 434                                 let clif_ty = fx.clif_type(layout.ty).unwrap();
 435                                 let zero = fx.bcx.ins().iconst(clif_ty, 0);
 436                                 fx.bcx.ins().isub(zero, val)
 437                             }
 438                             ty::Float(_) => fx.bcx.ins().fneg(val),
 439                             _ => unimplemented!("un op Neg for {:?}", layout.ty),
 440                         },
 441                     };
 442                     lval.write_cvalue(fx, CValue::ByVal(res, layout));
 443                 }
 444                 Rvalue::Cast(CastKind::ReifyFnPointer, operand, ty) => {
 445                     let layout = fx.layout_of(ty);
 446                     match fx.monomorphize(&operand.ty(&fx.mir.local_decls, fx.tcx)).sty {
 447                         ty::FnDef(def_id, substs) => {
 448                             let func_ref = fx.get_function_ref(
 449                                 Instance::resolve(fx.tcx, ParamEnv::reveal_all(), def_id, substs).unwrap(),
 450                             );
 451                             let func_addr = fx.bcx.ins().func_addr(fx.pointer_type, func_ref);
 452                             lval.write_cvalue(fx, CValue::ByVal(func_addr, layout));
 453                         }
 454                         _ => bug!("Trying to ReifyFnPointer on non FnDef {:?}", ty),
 455                     }
 456                 }
 457                 Rvalue::Cast(CastKind::UnsafeFnPointer, operand, ty) => {
 458                     let operand = trans_operand(fx, operand);
 459                     let layout = fx.layout_of(ty);
 460                     lval.write_cvalue(fx, operand.unchecked_cast_to(layout));
 461                 }
 462                 Rvalue::Cast(CastKind::Misc, operand, to_ty) => {
 463                     let operand = trans_operand(fx, operand);
 464                     let from_ty = operand.layout().ty;
 465                     match (&from_ty.sty, &to_ty.sty) {
 466                         (ty::Ref(..), ty::Ref(..))
 467                         | (ty::Ref(..), ty::RawPtr(..))
 468                         | (ty::RawPtr(..), ty::Ref(..))
 469                         | (ty::RawPtr(..), ty::RawPtr(..))
 470                         | (ty::FnPtr(..), ty::RawPtr(..)) => {
 471                             lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
 472                         }
 473                         (ty::RawPtr(..), ty::Uint(_))
 474                         | (ty::RawPtr(..), ty::Int(_))
 475                         | (ty::FnPtr(..), ty::Uint(_))
 476                             if to_ty.sty == fx.tcx.types.usize.sty
 477                                 || to_ty.sty == fx.tcx.types.isize.sty
 478                                 || fx.clif_type(to_ty).unwrap() == pointer_ty(fx.tcx) =>
 479                         {
 480                             lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
 481                         }
 482                         (ty::Uint(_), ty::RawPtr(..)) if from_ty.sty == fx.tcx.types.usize.sty => {
 483                             lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
 484                         }
 485                         (ty::Char, ty::Uint(_))
 486                         | (ty::Uint(_), ty::Char)
 487                         | (ty::Uint(_), ty::Int(_))
 488                         | (ty::Uint(_), ty::Uint(_)) => {
 489                             let from = operand.load_scalar(fx);
 490                             let res = crate::common::clif_intcast(
 491                                 fx,
 492                                 from,
 493                                 fx.clif_type(to_ty).unwrap(),
 494                                 false,
 495                             );
 496                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 497                         }
 498                         (ty::Int(_), ty::Int(_)) | (ty::Int(_), ty::Uint(_)) => {
 499                             let from = operand.load_scalar(fx);
 500                             let res = crate::common::clif_intcast(
 501                                 fx,
 502                                 from,
 503                                 fx.clif_type(to_ty).unwrap(),
 504                                 true,
 505                             );
 506                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 507                         }
 508                         (ty::Float(from_flt), ty::Float(to_flt)) => {
 509                             let from = operand.load_scalar(fx);
 510                             let res = match (from_flt, to_flt) {
 511                                 (FloatTy::F32, FloatTy::F64) => {
 512                                     fx.bcx.ins().fpromote(types::F64, from)
 513                                 }
 514                                 (FloatTy::F64, FloatTy::F32) => {
 515                                     fx.bcx.ins().fdemote(types::F32, from)
 516                                 }
 517                                 _ => from,
 518                             };
 519                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 520                         }
 521                         (ty::Int(_), ty::Float(_)) => {
 522                             let from_ty = fx.clif_type(from_ty).unwrap();
 523                             let from = operand.load_scalar(fx);
 524                             // FIXME missing encoding for fcvt_from_sint.f32.i8
 525                             let from = if from_ty == types::I8 || from_ty == types::I16 {
 526                                 fx.bcx.ins().sextend(types::I32, from)
 527                             } else {
 528                                 from
 529                             };
 530                             let f_type = fx.clif_type(to_ty).unwrap();
 531                             let res = fx.bcx.ins().fcvt_from_sint(f_type, from);
 532                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 533                         }
 534                         (ty::Uint(_), ty::Float(_)) => {
 535                             let from_ty = fx.clif_type(from_ty).unwrap();
 536                             let from = operand.load_scalar(fx);
 537                             // FIXME missing encoding for fcvt_from_uint.f32.i8
 538                             let from = if from_ty == types::I8 || from_ty == types::I16 {
 539                                 fx.bcx.ins().uextend(types::I32, from)
 540                             } else {
 541                                 from
 542                             };
 543                             let f_type = fx.clif_type(to_ty).unwrap();
 544                             let res = fx.bcx.ins().fcvt_from_uint(f_type, from);
 545                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 546                         }
 547                         (ty::Bool, ty::Uint(_)) | (ty::Bool, ty::Int(_)) => {
 548                             let to_ty = fx.clif_type(to_ty).unwrap();
 549                             let from = operand.load_scalar(fx);
 550                             let res = if to_ty != types::I8 {
 551                                 fx.bcx.ins().uextend(to_ty, from)
 552                             } else {
 553                                 from
 554                             };
 555                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 556                         }
 557                         (ty::Adt(adt_def, _substs), ty::Uint(_)) | (ty::Adt(adt_def, _substs), ty::Int(_)) if adt_def.is_enum() => {
 558                             let discr = trans_get_discriminant(fx, operand, fx.layout_of(to_ty));
 559                             lval.write_cvalue(fx, discr);
 560                         }
 561                         _ => unimpl!("rval misc {:?} {:?}", from_ty, to_ty),
 562                     }
 563                 }
 564                 Rvalue::Cast(CastKind::ClosureFnPointer, operand, ty) => {
 565                     unimplemented!("rval closure_fn_ptr {:?} {:?}", operand, ty)
 566                 }
 567                 Rvalue::Cast(CastKind::Unsize, operand, _ty) => {
 568                     let operand = trans_operand(fx, operand);
 569                     operand.unsize_value(fx, lval);
 570                 }
 571                 Rvalue::Discriminant(place) => {
 572                     let place = trans_place(fx, place).to_cvalue(fx);
 573                     let discr = trans_get_discriminant(fx, place, dest_layout);
 574                     lval.write_cvalue(fx, discr);
 575                 }
 576                 Rvalue::Repeat(operand, times) => {
 577                     let operand = trans_operand(fx, operand);
 578                     for i in 0..*times {
 579                         let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
 580                         let to = lval.place_index(fx, index);
 581                         to.write_cvalue(fx, operand);
 582                     }
 583                 }
 584                 Rvalue::Len(place) => {
 585                     let place = trans_place(fx, place);
 586                     let usize_layout = fx.layout_of(fx.tcx.types.usize);
 587                     let len = codegen_array_len(fx, place);
 588                     lval.write_cvalue(fx, CValue::ByVal(len, usize_layout));
 589                 }
 590                 Rvalue::NullaryOp(NullOp::Box, content_ty) => {
 591                     use rustc::middle::lang_items::ExchangeMallocFnLangItem;
 592
 593                     let usize_type = fx.clif_type(fx.tcx.types.usize).unwrap();
 594                     let layout = fx.layout_of(content_ty);
 595                     let llsize = fx.bcx.ins().iconst(usize_type, layout.size.bytes() as i64);
 596                     let llalign = fx
 597                         .bcx
 598                         .ins()
 599                         .iconst(usize_type, layout.align.abi.bytes() as i64);
 600                     let box_layout = fx.layout_of(fx.tcx.mk_box(content_ty));
 601
 602                     // Allocate space:
 603                     let def_id = match fx.tcx.lang_items().require(ExchangeMallocFnLangItem) {
 604                         Ok(id) => id,
 605                         Err(s) => {
 606                             fx.tcx
 607                                 .sess
 608                                 .fatal(&format!("allocation of `{}` {}", box_layout.ty, s));
 609                         }
 610                     };
 611                     let instance = ty::Instance::mono(fx.tcx, def_id);
 612                     let func_ref = fx.get_function_ref(instance);
 613                     let call = fx.bcx.ins().call(func_ref, &[llsize, llalign]);
 614                     let ptr = fx.bcx.inst_results(call)[0];
 615                     lval.write_cvalue(fx, CValue::ByVal(ptr, box_layout));
 616                 }
 617                 Rvalue::NullaryOp(NullOp::SizeOf, ty) => {
 618                     assert!(lval
 619                         .layout()
 620                         .ty
 621                         .is_sized(fx.tcx.at(DUMMY_SP), ParamEnv::reveal_all()));
 622                     let ty_size = fx.layout_of(ty).size.bytes();
 623                     let val = CValue::const_val(fx, fx.tcx.types.usize, ty_size as i64);
 624                     lval.write_cvalue(fx, val);
 625                 }
 626                 Rvalue::Aggregate(kind, operands) => match **kind {
 627                     AggregateKind::Array(_ty) => {
 628                         for (i, operand) in operands.into_iter().enumerate() {
 629                             let operand = trans_operand(fx, operand);
 630                             let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
 631                             let to = lval.place_index(fx, index);
 632                             to.write_cvalue(fx, operand);
 633                         }
 634                     }
 635                     _ => unimpl!("shouldn't exist at trans {:?}", rval),
 636                 },
 637             }
 638         }
 639         StatementKind::StorageLive(_)
 640         | StatementKind::StorageDead(_)
 641         | StatementKind::Nop
 642         | StatementKind::FakeRead(..)
 643         | StatementKind::Retag { .. }
 644         | StatementKind::AscribeUserType(..) => {}
 645
 646         StatementKind::InlineAsm { .. } => unimpl!("Inline assembly is not supported"),
 647     }
 648 }
 649
 650 fn codegen_array_len<'a, 'tcx: 'a>(
 651     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 652     place: CPlace<'tcx>,
 653 ) -> Value {
 654     match place.layout().ty.sty {
 655         ty::Array(_elem_ty, len) => {
 656             let len = crate::constant::force_eval_const(fx, len).unwrap_usize(fx.tcx) as i64;
 657             fx.bcx.ins().iconst(fx.pointer_type, len)
 658         }
 659         ty::Slice(_elem_ty) => {
 660             place.to_addr_maybe_unsized(fx).1.expect("Length metadata for slice place")
 661         }
 662         _ => bug!("Rvalue::Len({:?})", place),
 663     }
 664 }
 665
 666 pub fn trans_get_discriminant<'a, 'tcx: 'a>(
 667     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 668     value: CValue<'tcx>,
 669     dest_layout: TyLayout<'tcx>,
 670 ) -> CValue<'tcx> {
 671     let layout = value.layout();
 672
 673     if layout.abi == layout::Abi::Uninhabited {
 674         trap_unreachable(&mut fx.bcx);
 675     }
 676     match layout.variants {
 677         layout::Variants::Single { index } => {
 678             let discr_val = layout
 679                 .ty
 680                 .ty_adt_def()
 681                 .map_or(index.as_u32() as u128, |def| {
 682                     def.discriminant_for_variant(fx.tcx, index).val
 683                 });
 684             return CValue::const_val(fx, dest_layout.ty, discr_val as u64 as i64);
 685         }
 686         layout::Variants::Tagged { .. } | layout::Variants::NicheFilling { .. } => {}
 687     }
 688
 689     let discr = value.value_field(fx, mir::Field::new(0));
 690     let discr_ty = discr.layout().ty;
 691     let lldiscr = discr.load_scalar(fx);
 692     match layout.variants {
 693         layout::Variants::Single { .. } => bug!(),
 694         layout::Variants::Tagged { ref tag, .. } => {
 695             let signed = match tag.value {
 696                 layout::Int(_, signed) => signed,
 697                 _ => false,
 698             };
 699             let val = clif_intcast(fx, lldiscr, fx.clif_type(dest_layout.ty).unwrap(), signed);
 700             return CValue::ByVal(val, dest_layout);
 701         }
 702         layout::Variants::NicheFilling {
 703             dataful_variant,
 704             ref niche_variants,
 705             niche_start,
 706             ..
 707         } => {
 708             let niche_llty = fx.clif_type(discr_ty).unwrap();
 709             let dest_clif_ty = fx.clif_type(dest_layout.ty).unwrap();
 710             if niche_variants.start() == niche_variants.end() {
 711                 let b = fx
 712                     .bcx
 713                     .ins()
 714                     .icmp_imm(IntCC::Equal, lldiscr, niche_start as u64 as i64);
 715                 let if_true = fx
 716                     .bcx
 717                     .ins()
 718                     .iconst(dest_clif_ty, niche_variants.start().as_u32() as i64);
 719                 let if_false = fx
 720                     .bcx
 721                     .ins()
 722                     .iconst(dest_clif_ty, dataful_variant.as_u32() as i64);
 723                 let val = fx.bcx.ins().select(b, if_true, if_false);
 724                 return CValue::ByVal(val, dest_layout);
 725             } else {
 726                 // Rebase from niche values to discriminant values.
 727                 let delta = niche_start.wrapping_sub(niche_variants.start().as_u32() as u128);
 728                 let delta = fx.bcx.ins().iconst(niche_llty, delta as u64 as i64);
 729                 let lldiscr = fx.bcx.ins().isub(lldiscr, delta);
 730                 let b = fx.bcx.ins().icmp_imm(
 731                     IntCC::UnsignedLessThanOrEqual,
 732                     lldiscr,
 733                     niche_variants.end().as_u32() as i64,
 734                 );
 735                 let if_true =
 736                     clif_intcast(fx, lldiscr, fx.clif_type(dest_layout.ty).unwrap(), false);
 737                 let if_false = fx
 738                     .bcx
 739                     .ins()
 740                     .iconst(dest_clif_ty, dataful_variant.as_u32() as i64);
 741                 let val = fx.bcx.ins().select(b, if_true, if_false);
 742                 return CValue::ByVal(val, dest_layout);
 743             }
 744         }
 745     }
 746 }
 747
 748 macro_rules! binop_match {
 749     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, bug) => {
 750         bug!("binop {} on {} lhs: {:?} rhs: {:?}", stringify!($var), $bug_fmt, $lhs, $rhs)
 751     };
 752     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, icmp($cc:ident)) => {{
 753         assert_eq!($fx.tcx.types.bool, $ret_ty);
 754         let ret_layout = $fx.layout_of($ret_ty);
 755
 756         let b = $fx.bcx.ins().icmp(IntCC::$cc, $lhs, $rhs);
 757         CValue::ByVal($fx.bcx.ins().bint(types::I8, b), ret_layout)
 758     }};
 759     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, fcmp($cc:ident)) => {{
 760         assert_eq!($fx.tcx.types.bool, $ret_ty);
 761         let ret_layout = $fx.layout_of($ret_ty);
 762         let b = $fx.bcx.ins().fcmp(FloatCC::$cc, $lhs, $rhs);
 763         CValue::ByVal($fx.bcx.ins().bint(types::I8, b), ret_layout)
 764     }};
 765     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, custom(|| $body:expr)) => {{
 766         $body
 767     }};
 768     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, $name:ident) => {{
 769         let ret_layout = $fx.layout_of($ret_ty);
 770         CValue::ByVal($fx.bcx.ins().$name($lhs, $rhs), ret_layout)
 771     }};
 772     (
 773         $fx:expr, $bin_op:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, $bug_fmt:expr;
 774         $(
 775             $var:ident ($sign:pat) $name:tt $( ( $($next:tt)* ) )? ;
 776         )*
 777     ) => {{
 778         let lhs = $lhs.load_scalar($fx);
 779         let rhs = $rhs.load_scalar($fx);
 780         match ($bin_op, $signed) {
 781             $(
 782                 (BinOp::$var, $sign) => binop_match!(@single $fx, $bug_fmt, $var, $signed, lhs, rhs, $ret_ty, $name $( ( $($next)* ) )?),
 783             )*
 784         }
 785     }}
 786 }
 787
 788 fn trans_bool_binop<'a, 'tcx: 'a>(
 789     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 790     bin_op: BinOp,
 791     lhs: CValue<'tcx>,
 792     rhs: CValue<'tcx>,
 793     ty: Ty<'tcx>,
 794 ) -> CValue<'tcx> {
 795     let res = binop_match! {
 796         fx, bin_op, false, lhs, rhs, ty, "bool";
 797         Add (_) bug;
 798         Sub (_) bug;
 799         Mul (_) bug;
 800         Div (_) bug;
 801         Rem (_) bug;
 802         BitXor (_) bxor;
 803         BitAnd (_) band;
 804         BitOr (_) bor;
 805         Shl (_) bug;
 806         Shr (_) bug;
 807
 808         Eq (_) icmp(Equal);
 809         Lt (_) icmp(UnsignedLessThan);
 810         Le (_) icmp(UnsignedLessThanOrEqual);
 811         Ne (_) icmp(NotEqual);
 812         Ge (_) icmp(UnsignedGreaterThanOrEqual);
 813         Gt (_) icmp(UnsignedGreaterThan);
 814
 815         Offset (_) bug;
 816     };
 817
 818     res
 819 }
 820
 821 pub fn trans_int_binop<'a, 'tcx: 'a>(
 822     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 823     bin_op: BinOp,
 824     lhs: CValue<'tcx>,
 825     rhs: CValue<'tcx>,
 826     out_ty: Ty<'tcx>,
 827     signed: bool,
 828 ) -> CValue<'tcx> {
 829     if bin_op != BinOp::Shl && bin_op != BinOp::Shr {
 830         assert_eq!(
 831             lhs.layout().ty,
 832             rhs.layout().ty,
 833             "int binop requires lhs and rhs of same type"
 834         );
 835     }
 836     binop_match! {
 837         fx, bin_op, signed, lhs, rhs, out_ty, "int/uint";
 838         Add (_) iadd;
 839         Sub (_) isub;
 840         Mul (_) imul;
 841         Div (false) udiv;
 842         Div (true) sdiv;
 843         Rem (false) urem;
 844         Rem (true) srem;
 845         BitXor (_) bxor;
 846         BitAnd (_) band;
 847         BitOr (_) bor;
 848         Shl (_) ishl;
 849         Shr (false) ushr;
 850         Shr (true) sshr;
 851
 852         Eq (_) icmp(Equal);
 853         Lt (false) icmp(UnsignedLessThan);
 854         Lt (true) icmp(SignedLessThan);
 855         Le (false) icmp(UnsignedLessThanOrEqual);
 856         Le (true) icmp(SignedLessThanOrEqual);
 857         Ne (_) icmp(NotEqual);
 858         Ge (false) icmp(UnsignedGreaterThanOrEqual);
 859         Ge (true) icmp(SignedGreaterThanOrEqual);
 860         Gt (false) icmp(UnsignedGreaterThan);
 861         Gt (true) icmp(SignedGreaterThan);
 862
 863         Offset (_) bug;
 864     }
 865 }
 866
 867 pub fn trans_checked_int_binop<'a, 'tcx: 'a>(
 868     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 869     bin_op: BinOp,
 870     in_lhs: CValue<'tcx>,
 871     in_rhs: CValue<'tcx>,
 872     out_ty: Ty<'tcx>,
 873     signed: bool,
 874 ) -> CValue<'tcx> {
 875     if bin_op != BinOp::Shl && bin_op != BinOp::Shr {
 876         assert_eq!(
 877             in_lhs.layout().ty,
 878             in_rhs.layout().ty,
 879             "checked int binop requires lhs and rhs of same type"
 880         );
 881     }
 882
 883     let lhs = in_lhs.load_scalar(fx);
 884     let rhs = in_rhs.load_scalar(fx);
 885     let res = match bin_op {
 886         BinOp::Add => fx.bcx.ins().iadd(lhs, rhs),
 887         BinOp::Sub => fx.bcx.ins().isub(lhs, rhs),
 888         BinOp::Mul => fx.bcx.ins().imul(lhs, rhs),
 889         BinOp::Shl => fx.bcx.ins().ishl(lhs, rhs),
 890         BinOp::Shr => {
 891             if !signed {
 892                 fx.bcx.ins().ushr(lhs, rhs)
 893             } else {
 894                 fx.bcx.ins().sshr(lhs, rhs)
 895             }
 896         }
 897         _ => bug!(
 898             "binop {:?} on checked int/uint lhs: {:?} rhs: {:?}",
 899             bin_op,
 900             in_lhs,
 901             in_rhs
 902         ),
 903     };
 904
 905     // TODO: check for overflow
 906     let has_overflow = fx.bcx.ins().iconst(types::I8, 0);
 907
 908     let out_place = CPlace::new_stack_slot(fx, out_ty);
 909     let out_layout = out_place.layout();
 910     out_place.write_cvalue(fx, CValue::ByValPair(res, has_overflow, out_layout));
 911
 912     out_place.to_cvalue(fx)
 913 }
 914
 915 fn trans_float_binop<'a, 'tcx: 'a>(
 916     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 917     bin_op: BinOp,
 918     lhs: CValue<'tcx>,
 919     rhs: CValue<'tcx>,
 920     ty: Ty<'tcx>,
 921 ) -> CValue<'tcx> {
 922     let res = binop_match! {
 923         fx, bin_op, false, lhs, rhs, ty, "float";
 924         Add (_) fadd;
 925         Sub (_) fsub;
 926         Mul (_) fmul;
 927         Div (_) fdiv;
 928         Rem (_) custom(|| {
 929             assert_eq!(lhs.layout().ty, ty);
 930             assert_eq!(rhs.layout().ty, ty);
 931             match ty.sty {
 932                 ty::Float(FloatTy::F32) => fx.easy_call("fmodf", &[lhs, rhs], ty),
 933                 ty::Float(FloatTy::F64) => fx.easy_call("fmod", &[lhs, rhs], ty),
 934                 _ => bug!(),
 935             }
 936         });
 937         BitXor (_) bxor;
 938         BitAnd (_) band;
 939         BitOr (_) bor;
 940         Shl (_) bug;
 941         Shr (_) bug;
 942
 943         Eq (_) fcmp(Equal);
 944         Lt (_) fcmp(LessThan);
 945         Le (_) fcmp(LessThanOrEqual);
 946         Ne (_) fcmp(NotEqual);
 947         Ge (_) fcmp(GreaterThanOrEqual);
 948         Gt (_) fcmp(GreaterThan);
 949
 950         Offset (_) bug;
 951     };
 952
 953     res
 954 }
 955
 956 fn trans_char_binop<'a, 'tcx: 'a>(
 957     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 958     bin_op: BinOp,
 959     lhs: CValue<'tcx>,
 960     rhs: CValue<'tcx>,
 961     ty: Ty<'tcx>,
 962 ) -> CValue<'tcx> {
 963     let res = binop_match! {
 964         fx, bin_op, false, lhs, rhs, ty, "char";
 965         Add (_) bug;
 966         Sub (_) bug;
 967         Mul (_) bug;
 968         Div (_) bug;
 969         Rem (_) bug;
 970         BitXor (_) bug;
 971         BitAnd (_) bug;
 972         BitOr (_) bug;
 973         Shl (_) bug;
 974         Shr (_) bug;
 975
 976         Eq (_) icmp(Equal);
 977         Lt (_) icmp(UnsignedLessThan);
 978         Le (_) icmp(UnsignedLessThanOrEqual);
 979         Ne (_) icmp(NotEqual);
 980         Ge (_) icmp(UnsignedGreaterThanOrEqual);
 981         Gt (_) icmp(UnsignedGreaterThan);
 982
 983         Offset (_) bug;
 984     };
 985
 986     res
 987 }
 988
 989 fn trans_ptr_binop<'a, 'tcx: 'a>(
 990     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 991     bin_op: BinOp,
 992     lhs: CValue<'tcx>,
 993     rhs: CValue<'tcx>,
 994     ret_ty: Ty<'tcx>,
 995 ) -> CValue<'tcx> {
 996     let not_fat = match lhs.layout().ty.sty {
 997         ty::RawPtr(TypeAndMut { ty, mutbl: _ }) => ty.is_sized(fx.tcx.at(DUMMY_SP), ParamEnv::reveal_all()),
 998         ty::FnPtr(..) => true,
 999         _ => bug!("trans_ptr_binop on non ptr"),
1000     };
1001     if not_fat {
1002         binop_match! {
1003             fx, bin_op, false, lhs, rhs, ret_ty, "ptr";
1004             Add (_) bug;
1005             Sub (_) bug;
1006             Mul (_) bug;
1007             Div (_) bug;
1008             Rem (_) bug;
1009             BitXor (_) bug;
1010             BitAnd (_) bug;
1011             BitOr (_) bug;
1012             Shl (_) bug;
1013             Shr (_) bug;
1014
1015             Eq (_) icmp(Equal);
1016             Lt (_) icmp(UnsignedLessThan);
1017             Le (_) icmp(UnsignedLessThanOrEqual);
1018             Ne (_) icmp(NotEqual);
1019             Ge (_) icmp(UnsignedGreaterThanOrEqual);
1020             Gt (_) icmp(UnsignedGreaterThan);
1021
1022             Offset (_) iadd;
1023         }
1024     } else {
1025         let lhs = lhs.load_value_pair(fx).0;
1026         let rhs = rhs.load_value_pair(fx).0;
1027         let res = match bin_op {
1028             BinOp::Eq => fx.bcx.ins().icmp(IntCC::Equal, lhs, rhs),
1029             BinOp::Ne => fx.bcx.ins().icmp(IntCC::NotEqual, lhs, rhs),
1030             _ => unimplemented!(
1031                 "trans_ptr_binop({:?}, <fat ptr>, <fat ptr>) not implemented",
1032                 bin_op
1033             ),
1034         };
1035
1036         assert_eq!(fx.tcx.types.bool, ret_ty);
1037         let ret_layout = fx.layout_of(ret_ty);
1038         CValue::ByVal(fx.bcx.ins().bint(types::I8, res), ret_layout)
1039     }
1040 }
1041
1042 pub fn trans_place<'a, 'tcx: 'a>(
1043     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1044     place: &Place<'tcx>,
1045 ) -> CPlace<'tcx> {
1046     match place {
1047         Place::Local(local) => fx.get_local_place(*local),
1048         Place::Promoted(promoted) => crate::constant::trans_promoted(fx, promoted.0),
1049         Place::Static(static_) => crate::constant::codegen_static_ref(fx, static_),
1050         Place::Projection(projection) => {
1051             let base = trans_place(fx, &projection.base);
1052             match projection.elem {
1053                 ProjectionElem::Deref => base.place_deref(fx),
1054                 ProjectionElem::Field(field, _ty) => base.place_field(fx, field),
1055                 ProjectionElem::Index(local) => {
1056                     let index = fx.get_local_place(local).to_cvalue(fx).load_scalar(fx);
1057                     base.place_index(fx, index)
1058                 }
1059                 ProjectionElem::ConstantIndex {
1060                     offset,
1061                     min_length: _,
1062                     from_end,
1063                 } => {
1064                     let index = if !from_end {
1065                         fx.bcx.ins().iconst(fx.pointer_type, offset as i64)
1066                     } else {
1067                         let len = codegen_array_len(fx, base);
1068                         fx.bcx.ins().iadd_imm(len, -(offset as i64))
1069                     };
1070                     base.place_index(fx, index)
1071                 }
1072                 ProjectionElem::Subslice { from, to } => unimpl!(
1073                     "projection subslice {:?} from {} to {}",
1074                     projection.base,
1075                     from,
1076                     to
1077                 ),
1078                 ProjectionElem::Downcast(_adt_def, variant) => base.downcast_variant(fx, variant),
1079             }
1080         }
1081     }
1082 }
1083
1084 pub fn trans_operand<'a, 'tcx>(
1085     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1086     operand: &Operand<'tcx>,
1087 ) -> CValue<'tcx> {
1088     match operand {
1089         Operand::Move(place) | Operand::Copy(place) => {
1090             let cplace = trans_place(fx, place);
1091             cplace.to_cvalue(fx)
1092         }
1093         Operand::Constant(const_) => crate::constant::trans_constant(fx, const_),
1094     }
1095 }