src/base.rs

   1 use crate::prelude::*;
   2
   3 struct PrintOnPanic<F: Fn() -> String>(F);
   4 impl<F: Fn() -> String> Drop for PrintOnPanic<F> {
   5     fn drop(&mut self) {
   6         if ::std::thread::panicking() {
   7             println!("{}", (self.0)());
   8         }
   9     }
  10 }
  11
  12 pub fn trans_mono_item<'a, 'clif, 'tcx: 'a, B: Backend + 'static>(
  13     cx: &mut crate::CodegenCx<'a, 'clif, 'tcx, B>,
  14     mono_item: MonoItem<'tcx>,
  15     linkage: Linkage,
  16 ) {
  17     let tcx = cx.tcx;
  18     match mono_item {
  19         MonoItem::Fn(inst) => {
  20             let _inst_guard =
  21                 PrintOnPanic(|| format!("{:?} {}", inst, tcx.symbol_name(inst).as_str()));
  22             debug_assert!(!inst.substs.needs_infer());
  23             let _mir_guard = PrintOnPanic(|| {
  24                 match inst.def {
  25                     InstanceDef::Item(_)
  26                     | InstanceDef::DropGlue(_, _)
  27                     | InstanceDef::Virtual(_, _)
  28                         if inst.def_id().krate == LOCAL_CRATE =>
  29                     {
  30                         let mut mir = ::std::io::Cursor::new(Vec::new());
  31                         crate::rustc_mir::util::write_mir_pretty(
  32                             tcx,
  33                             Some(inst.def_id()),
  34                             &mut mir,
  35                         )
  36                         .unwrap();
  37                         String::from_utf8(mir.into_inner()).unwrap()
  38                     }
  39                     _ => {
  40                         // FIXME fix write_mir_pretty for these instances
  41                         format!("{:#?}", tcx.instance_mir(inst.def))
  42                     }
  43                 }
  44             });
  45
  46             trans_fn(cx, inst, linkage);
  47         }
  48         MonoItem::Static(def_id) => {
  49             crate::constant::codegen_static(&mut cx.ccx, def_id);
  50         }
  51         MonoItem::GlobalAsm(node_id) => tcx
  52             .sess
  53             .fatal(&format!("Unimplemented global asm mono item {:?}", node_id)),
  54     }
  55 }
  56
  57 fn trans_fn<'a, 'clif, 'tcx: 'a, B: Backend + 'static>(
  58     cx: &mut crate::CodegenCx<'a, 'clif, 'tcx, B>,
  59     instance: Instance<'tcx>,
  60     linkage: Linkage,
  61 ) {
  62     let tcx = cx.tcx;
  63
  64     // Step 1. Get mir
  65     let mir = tcx.instance_mir(instance.def);
  66
  67     // Step 2. Declare function
  68     let (name, sig) = get_function_name_and_sig(tcx, instance);
  69     let func_id = cx.module
  70         .declare_function(&name, linkage, &sig)
  71         .unwrap();
  72     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         spans: Vec::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 spans = fx.spans.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, &spans[..]));
 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                 bug!("shouldn't exist at trans {:?}", bb_data.terminator());
 247             }
 248             TerminatorKind::Drop {
 249                 location,
 250                 target,
 251                 unwind: _,
 252             } => {
 253                 let ty = location.ty(fx.mir, fx.tcx).to_ty(fx.tcx);
 254                 let ty = fx.monomorphize(&ty);
 255                 let drop_fn = crate::rustc_mir::monomorphize::resolve_drop_in_place(fx.tcx, ty);
 256
 257                 if let ty::InstanceDef::DropGlue(_, None) = drop_fn.def {
 258                     // we don't actually need to drop anything
 259                 } else {
 260                     let drop_place = trans_place(fx, location);
 261                     let arg_place = CPlace::temp(
 262                         fx,
 263                         fx.tcx.mk_ref(
 264                             &ty::RegionKind::ReErased,
 265                             TypeAndMut {
 266                                 ty,
 267                                 mutbl: crate::rustc::hir::Mutability::MutMutable,
 268                             },
 269                         ),
 270                     );
 271                     drop_place.write_place_ref(fx, arg_place);
 272                     match ty.sty {
 273                         ty::Dynamic(..) => {
 274                             fx.tcx.sess.warn("Drop for trait object");
 275                         }
 276                         _ => {
 277                             let drop_fn_ty = drop_fn.ty(fx.tcx);
 278                             let arg_value = arg_place.to_cvalue(fx);
 279                             crate::abi::codegen_call_inner(
 280                                 fx,
 281                                 None,
 282                                 drop_fn_ty,
 283                                 vec![arg_value],
 284                                 None,
 285                             );
 286                         }
 287                     }
 288                     /*
 289                     let (args1, args2);
 290                     /*let mut args = if let Some(llextra) = place.llextra {
 291                         args2 = [place.llval, llextra];
 292                         &args2[..]
 293                     } else {
 294                         args1 = [place.llval];
 295                         &args1[..]
 296                     };*/
 297                     let (drop_fn, fn_ty) = match ty.sty {
 298                     ty::Dynamic(..) => {
 299                     let fn_ty = drop_fn.ty(bx.cx.tcx);
 300                     let sig = common::ty_fn_sig(bx.cx, fn_ty);
 301                     let sig = bx.tcx().normalize_erasing_late_bound_regions(
 302                     ty::ParamEnv::reveal_all(),
 303                     &sig,
 304                     );
 305                     let fn_ty = FnType::new_vtable(bx.cx, sig, &[]);
 306                     let vtable = args[1];
 307                     args = &args[..1];
 308                     (meth::DESTRUCTOR.get_fn(&bx, vtable, &fn_ty), fn_ty)
 309                     }
 310                     _ => {
 311                     let value = place.to_cvalue(fx);
 312                     (callee::get_fn(bx.cx, drop_fn),
 313                     FnType::of_instance(bx.cx, &drop_fn))
 314                     }
 315                     };
 316                     do_call(self, bx, fn_ty, drop_fn, args,
 317                     Some((ReturnDest::Nothing, target)),
 318                     unwind);*/
 319                 }
 320
 321                 let target_ebb = fx.get_ebb(*target);
 322                 fx.bcx.ins().jump(target_ebb, &[]);
 323             }
 324             TerminatorKind::GeneratorDrop => {
 325                 unimplemented!("terminator GeneratorDrop");
 326             }
 327         };
 328     }
 329
 330     fx.bcx.seal_all_blocks();
 331     fx.bcx.finalize();
 332 }
 333
 334 fn trans_stmt<'a, 'tcx: 'a>(
 335     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 336     cur_ebb: Ebb,
 337     stmt: &Statement<'tcx>,
 338 ) {
 339     let _print_guard = PrintOnPanic(|| format!("stmt {:?}", stmt));
 340
 341     fx.set_debug_loc(stmt.source_info);
 342
 343     #[cfg(debug_assertions)]
 344     match &stmt.kind {
 345         StatementKind::StorageLive(..) | StatementKind::StorageDead(..) => {} // Those are not very useful
 346         _ => {
 347             let inst = fx.bcx.func.layout.last_inst(cur_ebb).unwrap();
 348             fx.add_comment(inst, format!("{:?}", stmt));
 349         }
 350     }
 351
 352     match &stmt.kind {
 353         StatementKind::SetDiscriminant {
 354             place,
 355             variant_index,
 356         } => {
 357             let place = trans_place(fx, place);
 358             let layout = place.layout();
 359             if layout.for_variant(&*fx, *variant_index).abi == layout::Abi::Uninhabited {
 360                 return;
 361             }
 362             match layout.variants {
 363                 layout::Variants::Single { index } => {
 364                     assert_eq!(index, *variant_index);
 365                 }
 366                 layout::Variants::Tagged { .. } => {
 367                     let ptr = place.place_field(fx, mir::Field::new(0));
 368                     let to = layout
 369                         .ty
 370                         .ty_adt_def()
 371                         .unwrap()
 372                         .discriminant_for_variant(fx.tcx, *variant_index)
 373                         .val;
 374                     let discr = CValue::const_val(fx, ptr.layout().ty, to as u64 as i64);
 375                     ptr.write_cvalue(fx, discr);
 376                 }
 377                 layout::Variants::NicheFilling {
 378                     dataful_variant,
 379                     ref niche_variants,
 380                     niche_start,
 381                     ..
 382                 } => {
 383                     if *variant_index != dataful_variant {
 384                         let niche = place.place_field(fx, mir::Field::new(0));
 385                         //let niche_llty = niche.layout.immediate_llvm_type(bx.cx);
 386                         let niche_value =
 387                             ((variant_index.as_u32() - niche_variants.start().as_u32()) as u128)
 388                                 .wrapping_add(niche_start);
 389                         // FIXME(eddyb) Check the actual primitive type here.
 390                         let niche_llval = if niche_value == 0 {
 391                             CValue::const_val(fx, niche.layout().ty, 0)
 392                         } else {
 393                             CValue::const_val(fx, niche.layout().ty, niche_value as u64 as i64)
 394                         };
 395                         niche.write_cvalue(fx, niche_llval);
 396                     }
 397                 }
 398             }
 399         }
 400         StatementKind::Assign(to_place, rval) => {
 401             let lval = trans_place(fx, to_place);
 402             let dest_layout = lval.layout();
 403             match &**rval {
 404                 Rvalue::Use(operand) => {
 405                     let val = trans_operand(fx, operand);
 406                     lval.write_cvalue(fx, val);
 407                 }
 408                 Rvalue::Ref(_, _, place) => {
 409                     let place = trans_place(fx, place);
 410                     place.write_place_ref(fx, lval);
 411                 }
 412                 Rvalue::BinaryOp(bin_op, lhs, rhs) => {
 413                     let ty = fx.monomorphize(&lhs.ty(fx.mir, fx.tcx));
 414                     let lhs = trans_operand(fx, lhs);
 415                     let rhs = trans_operand(fx, rhs);
 416
 417                     let res = match ty.sty {
 418                         ty::Bool => trans_bool_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 419                         ty::Uint(_) => {
 420                             trans_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, false)
 421                         }
 422                         ty::Int(_) => {
 423                             trans_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, true)
 424                         }
 425                         ty::Float(_) => trans_float_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 426                         ty::Char => trans_char_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 427                         ty::RawPtr(..) => trans_ptr_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 428                         _ => unimplemented!("binop {:?} for {:?}", bin_op, ty),
 429                     };
 430                     lval.write_cvalue(fx, res);
 431                 }
 432                 Rvalue::CheckedBinaryOp(bin_op, lhs, rhs) => {
 433                     let ty = fx.monomorphize(&lhs.ty(fx.mir, fx.tcx));
 434                     let lhs = trans_operand(fx, lhs);
 435                     let rhs = trans_operand(fx, rhs);
 436
 437                     let res = match ty.sty {
 438                         ty::Uint(_) => {
 439                             trans_checked_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, false)
 440                         }
 441                         ty::Int(_) => {
 442                             trans_checked_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, true)
 443                         }
 444                         _ => unimplemented!("checked binop {:?} for {:?}", bin_op, ty),
 445                     };
 446                     lval.write_cvalue(fx, res);
 447                 }
 448                 Rvalue::UnaryOp(un_op, operand) => {
 449                     let operand = trans_operand(fx, operand);
 450                     let layout = operand.layout();
 451                     let val = operand.load_scalar(fx);
 452                     let res = match un_op {
 453                         UnOp::Not => {
 454                             match layout.ty.sty {
 455                                 ty::Bool => {
 456                                     let val = fx.bcx.ins().uextend(types::I32, val); // WORKAROUND for CraneStation/cranelift#466
 457                                     let res = fx.bcx.ins().icmp_imm(IntCC::Equal, val, 0);
 458                                     fx.bcx.ins().bint(types::I8, res)
 459                                 }
 460                                 ty::Uint(_) | ty::Int(_) => fx.bcx.ins().bnot(val),
 461                                 _ => unimplemented!("un op Not for {:?}", layout.ty),
 462                             }
 463                         }
 464                         UnOp::Neg => match layout.ty.sty {
 465                             ty::Int(_) => {
 466                                 let clif_ty = fx.clif_type(layout.ty).unwrap();
 467                                 let zero = fx.bcx.ins().iconst(clif_ty, 0);
 468                                 fx.bcx.ins().isub(zero, val)
 469                             }
 470                             ty::Float(_) => fx.bcx.ins().fneg(val),
 471                             _ => unimplemented!("un op Neg for {:?}", layout.ty),
 472                         },
 473                     };
 474                     lval.write_cvalue(fx, CValue::ByVal(res, layout));
 475                 }
 476                 Rvalue::Cast(CastKind::ReifyFnPointer, operand, ty) => {
 477                     let operand = trans_operand(fx, operand);
 478                     let layout = fx.layout_of(ty);
 479                     lval.write_cvalue(fx, operand.unchecked_cast_to(layout));
 480                 }
 481                 Rvalue::Cast(CastKind::UnsafeFnPointer, operand, ty) => {
 482                     let operand = trans_operand(fx, operand);
 483                     let layout = fx.layout_of(ty);
 484                     lval.write_cvalue(fx, operand.unchecked_cast_to(layout));
 485                 }
 486                 Rvalue::Cast(CastKind::Misc, operand, to_ty) => {
 487                     let operand = trans_operand(fx, operand);
 488                     let from_ty = operand.layout().ty;
 489                     match (&from_ty.sty, &to_ty.sty) {
 490                         (ty::Ref(..), ty::Ref(..))
 491                         | (ty::Ref(..), ty::RawPtr(..))
 492                         | (ty::RawPtr(..), ty::Ref(..))
 493                         | (ty::RawPtr(..), ty::RawPtr(..))
 494                         | (ty::FnPtr(..), ty::RawPtr(..)) => {
 495                             lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
 496                         }
 497                         (ty::RawPtr(..), ty::Uint(_))
 498                         | (ty::RawPtr(..), ty::Int(_))
 499                         | (ty::FnPtr(..), ty::Uint(_))
 500                             if to_ty.sty == fx.tcx.types.usize.sty
 501                                 || to_ty.sty == fx.tcx.types.isize.sty
 502                                 || fx.clif_type(to_ty).unwrap() == pointer_ty(fx.tcx) =>
 503                         {
 504                             lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
 505                         }
 506                         (ty::Uint(_), ty::RawPtr(..)) if from_ty.sty == fx.tcx.types.usize.sty => {
 507                             lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
 508                         }
 509                         (ty::Char, ty::Uint(_))
 510                         | (ty::Uint(_), ty::Char)
 511                         | (ty::Uint(_), ty::Int(_))
 512                         | (ty::Uint(_), ty::Uint(_)) => {
 513                             let from = operand.load_scalar(fx);
 514                             let res = crate::common::clif_intcast(
 515                                 fx,
 516                                 from,
 517                                 fx.clif_type(to_ty).unwrap(),
 518                                 false,
 519                             );
 520                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 521                         }
 522                         (ty::Int(_), ty::Int(_)) | (ty::Int(_), ty::Uint(_)) => {
 523                             let from = operand.load_scalar(fx);
 524                             let res = crate::common::clif_intcast(
 525                                 fx,
 526                                 from,
 527                                 fx.clif_type(to_ty).unwrap(),
 528                                 true,
 529                             );
 530                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 531                         }
 532                         (ty::Float(from_flt), ty::Float(to_flt)) => {
 533                             let from = operand.load_scalar(fx);
 534                             let res = match (from_flt, to_flt) {
 535                                 (FloatTy::F32, FloatTy::F64) => {
 536                                     fx.bcx.ins().fpromote(types::F64, from)
 537                                 }
 538                                 (FloatTy::F64, FloatTy::F32) => {
 539                                     fx.bcx.ins().fdemote(types::F32, from)
 540                                 }
 541                                 _ => from,
 542                             };
 543                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 544                         }
 545                         (ty::Int(_), ty::Float(_)) => {
 546                             let from_ty = fx.clif_type(from_ty).unwrap();
 547                             let from = operand.load_scalar(fx);
 548                             // FIXME missing encoding for fcvt_from_sint.f32.i8
 549                             let from = if from_ty == types::I8 || from_ty == types::I16 {
 550                                 fx.bcx.ins().sextend(types::I32, from)
 551                             } else {
 552                                 from
 553                             };
 554                             let f_type = fx.clif_type(to_ty).unwrap();
 555                             let res = fx.bcx.ins().fcvt_from_sint(f_type, from);
 556                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 557                         }
 558                         (ty::Uint(_), ty::Float(_)) => {
 559                             let from_ty = fx.clif_type(from_ty).unwrap();
 560                             let from = operand.load_scalar(fx);
 561                             // FIXME missing encoding for fcvt_from_uint.f32.i8
 562                             let from = if from_ty == types::I8 || from_ty == types::I16 {
 563                                 fx.bcx.ins().uextend(types::I32, from)
 564                             } else {
 565                                 from
 566                             };
 567                             let f_type = fx.clif_type(to_ty).unwrap();
 568                             let res = fx.bcx.ins().fcvt_from_uint(f_type, from);
 569                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 570                         }
 571                         (ty::Bool, ty::Uint(_)) | (ty::Bool, ty::Int(_)) => {
 572                             let to_ty = fx.clif_type(to_ty).unwrap();
 573                             let from = operand.load_scalar(fx);
 574                             let res = if to_ty != types::I8 {
 575                                 fx.bcx.ins().uextend(to_ty, from)
 576                             } else {
 577                                 from
 578                             };
 579                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 580                         }
 581                         (ty::Adt(adt_def, _substs), ty::Uint(_)) | (ty::Adt(adt_def, _substs), ty::Int(_)) if adt_def.is_enum() => {
 582                             let discr = trans_get_discriminant(fx, operand, fx.layout_of(to_ty));
 583                             lval.write_cvalue(fx, discr);
 584                         }
 585                         _ => unimpl!("rval misc {:?} {:?}", from_ty, to_ty),
 586                     }
 587                 }
 588                 Rvalue::Cast(CastKind::ClosureFnPointer, operand, ty) => {
 589                     unimplemented!("rval closure_fn_ptr {:?} {:?}", operand, ty)
 590                 }
 591                 Rvalue::Cast(CastKind::Unsize, operand, _ty) => {
 592                     let operand = trans_operand(fx, operand);
 593                     operand.unsize_value(fx, lval);
 594                 }
 595                 Rvalue::Discriminant(place) => {
 596                     let place = trans_place(fx, place).to_cvalue(fx);
 597                     let discr = trans_get_discriminant(fx, place, dest_layout);
 598                     lval.write_cvalue(fx, discr);
 599                 }
 600                 Rvalue::Repeat(operand, times) => {
 601                     let operand = trans_operand(fx, operand);
 602                     for i in 0..*times {
 603                         let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
 604                         let to = lval.place_index(fx, index);
 605                         to.write_cvalue(fx, operand);
 606                     }
 607                 }
 608                 Rvalue::Len(place) => {
 609                     let place = trans_place(fx, place);
 610                     let usize_layout = fx.layout_of(fx.tcx.types.usize);
 611                     let len = codegen_array_len(fx, place);
 612                     lval.write_cvalue(fx, CValue::ByVal(len, usize_layout));
 613                 }
 614                 Rvalue::NullaryOp(NullOp::Box, content_ty) => {
 615                     use rustc::middle::lang_items::ExchangeMallocFnLangItem;
 616
 617                     let usize_type = fx.clif_type(fx.tcx.types.usize).unwrap();
 618                     let layout = fx.layout_of(content_ty);
 619                     let llsize = fx.bcx.ins().iconst(usize_type, layout.size.bytes() as i64);
 620                     let llalign = fx
 621                         .bcx
 622                         .ins()
 623                         .iconst(usize_type, layout.align.abi.bytes() as i64);
 624                     let box_layout = fx.layout_of(fx.tcx.mk_box(content_ty));
 625
 626                     // Allocate space:
 627                     let def_id = match fx.tcx.lang_items().require(ExchangeMallocFnLangItem) {
 628                         Ok(id) => id,
 629                         Err(s) => {
 630                             fx.tcx
 631                                 .sess
 632                                 .fatal(&format!("allocation of `{}` {}", box_layout.ty, s));
 633                         }
 634                     };
 635                     let instance = ty::Instance::mono(fx.tcx, def_id);
 636                     let func_ref = fx.get_function_ref(instance);
 637                     let call = fx.bcx.ins().call(func_ref, &[llsize, llalign]);
 638                     let ptr = fx.bcx.inst_results(call)[0];
 639                     lval.write_cvalue(fx, CValue::ByVal(ptr, box_layout));
 640                 }
 641                 Rvalue::NullaryOp(NullOp::SizeOf, ty) => {
 642                     assert!(lval
 643                         .layout()
 644                         .ty
 645                         .is_sized(fx.tcx.at(DUMMY_SP), ParamEnv::reveal_all()));
 646                     let ty_size = fx.layout_of(ty).size.bytes();
 647                     let val = CValue::const_val(fx, fx.tcx.types.usize, ty_size as i64);
 648                     lval.write_cvalue(fx, val);
 649                 }
 650                 Rvalue::Aggregate(kind, operands) => match **kind {
 651                     AggregateKind::Array(_ty) => {
 652                         for (i, operand) in operands.into_iter().enumerate() {
 653                             let operand = trans_operand(fx, operand);
 654                             let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
 655                             let to = lval.place_index(fx, index);
 656                             to.write_cvalue(fx, operand);
 657                         }
 658                     }
 659                     _ => unimpl!("shouldn't exist at trans {:?}", rval),
 660                 },
 661             }
 662         }
 663         StatementKind::StorageLive(_)
 664         | StatementKind::StorageDead(_)
 665         | StatementKind::Nop
 666         | StatementKind::FakeRead(..)
 667         | StatementKind::Retag { .. }
 668         | StatementKind::AscribeUserType(..) => {}
 669
 670         StatementKind::InlineAsm { .. } => unimpl!("Inline assembly is not supported"),
 671     }
 672 }
 673
 674 fn codegen_array_len<'a, 'tcx: 'a>(
 675     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 676     place: CPlace<'tcx>,
 677 ) -> Value {
 678     match place.layout().ty.sty {
 679         ty::Array(_elem_ty, len) => {
 680             let len = crate::constant::force_eval_const(fx, len).unwrap_usize(fx.tcx) as i64;
 681             fx.bcx.ins().iconst(fx.pointer_type, len)
 682         }
 683         ty::Slice(_elem_ty) => match place {
 684             CPlace::Addr(_, size, _) => size.unwrap(),
 685             CPlace::Var(_, _) => unreachable!(),
 686         },
 687         _ => bug!("Rvalue::Len({:?})", place),
 688     }
 689 }
 690
 691 pub fn trans_get_discriminant<'a, 'tcx: 'a>(
 692     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 693     value: CValue<'tcx>,
 694     dest_layout: TyLayout<'tcx>,
 695 ) -> CValue<'tcx> {
 696     let layout = value.layout();
 697
 698     if layout.abi == layout::Abi::Uninhabited {
 699         trap_unreachable(&mut fx.bcx);
 700     }
 701     match layout.variants {
 702         layout::Variants::Single { index } => {
 703             let discr_val = layout
 704                 .ty
 705                 .ty_adt_def()
 706                 .map_or(index.as_u32() as u128, |def| {
 707                     def.discriminant_for_variant(fx.tcx, index).val
 708                 });
 709             return CValue::const_val(fx, dest_layout.ty, discr_val as u64 as i64);
 710         }
 711         layout::Variants::Tagged { .. } | layout::Variants::NicheFilling { .. } => {}
 712     }
 713
 714     let discr = value.value_field(fx, mir::Field::new(0));
 715     let discr_ty = discr.layout().ty;
 716     let lldiscr = discr.load_scalar(fx);
 717     match layout.variants {
 718         layout::Variants::Single { .. } => bug!(),
 719         layout::Variants::Tagged { ref tag, .. } => {
 720             let signed = match tag.value {
 721                 layout::Int(_, signed) => signed,
 722                 _ => false,
 723             };
 724             let val = clif_intcast(fx, lldiscr, fx.clif_type(dest_layout.ty).unwrap(), signed);
 725             return CValue::ByVal(val, dest_layout);
 726         }
 727         layout::Variants::NicheFilling {
 728             dataful_variant,
 729             ref niche_variants,
 730             niche_start,
 731             ..
 732         } => {
 733             let niche_llty = fx.clif_type(discr_ty).unwrap();
 734             let dest_clif_ty = fx.clif_type(dest_layout.ty).unwrap();
 735             if niche_variants.start() == niche_variants.end() {
 736                 let b = fx
 737                     .bcx
 738                     .ins()
 739                     .icmp_imm(IntCC::Equal, lldiscr, niche_start as u64 as i64);
 740                 let if_true = fx
 741                     .bcx
 742                     .ins()
 743                     .iconst(dest_clif_ty, niche_variants.start().as_u32() as i64);
 744                 let if_false = fx
 745                     .bcx
 746                     .ins()
 747                     .iconst(dest_clif_ty, dataful_variant.as_u32() as i64);
 748                 let val = fx.bcx.ins().select(b, if_true, if_false);
 749                 return CValue::ByVal(val, dest_layout);
 750             } else {
 751                 // Rebase from niche values to discriminant values.
 752                 let delta = niche_start.wrapping_sub(niche_variants.start().as_u32() as u128);
 753                 let delta = fx.bcx.ins().iconst(niche_llty, delta as u64 as i64);
 754                 let lldiscr = fx.bcx.ins().isub(lldiscr, delta);
 755                 let b = fx.bcx.ins().icmp_imm(
 756                     IntCC::UnsignedLessThanOrEqual,
 757                     lldiscr,
 758                     niche_variants.end().as_u32() as i64,
 759                 );
 760                 let if_true =
 761                     clif_intcast(fx, lldiscr, fx.clif_type(dest_layout.ty).unwrap(), false);
 762                 let if_false = fx
 763                     .bcx
 764                     .ins()
 765                     .iconst(dest_clif_ty, dataful_variant.as_u32() as i64);
 766                 let val = fx.bcx.ins().select(b, if_true, if_false);
 767                 return CValue::ByVal(val, dest_layout);
 768             }
 769         }
 770     }
 771 }
 772
 773 macro_rules! binop_match {
 774     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, bug) => {
 775         bug!("binop {} on {} lhs: {:?} rhs: {:?}", stringify!($var), $bug_fmt, $lhs, $rhs)
 776     };
 777     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, icmp($cc:ident)) => {{
 778         assert_eq!($fx.tcx.types.bool, $ret_ty);
 779         let ret_layout = $fx.layout_of($ret_ty);
 780
 781         let b = $fx.bcx.ins().icmp(IntCC::$cc, $lhs, $rhs);
 782         CValue::ByVal($fx.bcx.ins().bint(types::I8, b), ret_layout)
 783     }};
 784     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, fcmp($cc:ident)) => {{
 785         assert_eq!($fx.tcx.types.bool, $ret_ty);
 786         let ret_layout = $fx.layout_of($ret_ty);
 787         let b = $fx.bcx.ins().fcmp(FloatCC::$cc, $lhs, $rhs);
 788         CValue::ByVal($fx.bcx.ins().bint(types::I8, b), ret_layout)
 789     }};
 790     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, custom(|| $body:expr)) => {{
 791         $body
 792     }};
 793     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, $name:ident) => {{
 794         let ret_layout = $fx.layout_of($ret_ty);
 795         CValue::ByVal($fx.bcx.ins().$name($lhs, $rhs), ret_layout)
 796     }};
 797     (
 798         $fx:expr, $bin_op:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, $bug_fmt:expr;
 799         $(
 800             $var:ident ($sign:pat) $name:tt $( ( $($next:tt)* ) )? ;
 801         )*
 802     ) => {{
 803         let lhs = $lhs.load_scalar($fx);
 804         let rhs = $rhs.load_scalar($fx);
 805         match ($bin_op, $signed) {
 806             $(
 807                 (BinOp::$var, $sign) => binop_match!(@single $fx, $bug_fmt, $var, $signed, lhs, rhs, $ret_ty, $name $( ( $($next)* ) )?),
 808             )*
 809         }
 810     }}
 811 }
 812
 813 fn trans_bool_binop<'a, 'tcx: 'a>(
 814     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 815     bin_op: BinOp,
 816     lhs: CValue<'tcx>,
 817     rhs: CValue<'tcx>,
 818     ty: Ty<'tcx>,
 819 ) -> CValue<'tcx> {
 820     let res = binop_match! {
 821         fx, bin_op, false, lhs, rhs, ty, "bool";
 822         Add (_) bug;
 823         Sub (_) bug;
 824         Mul (_) bug;
 825         Div (_) bug;
 826         Rem (_) bug;
 827         BitXor (_) bxor;
 828         BitAnd (_) band;
 829         BitOr (_) bor;
 830         Shl (_) bug;
 831         Shr (_) bug;
 832
 833         Eq (_) icmp(Equal);
 834         Lt (_) icmp(UnsignedLessThan);
 835         Le (_) icmp(UnsignedLessThanOrEqual);
 836         Ne (_) icmp(NotEqual);
 837         Ge (_) icmp(UnsignedGreaterThanOrEqual);
 838         Gt (_) icmp(UnsignedGreaterThan);
 839
 840         Offset (_) bug;
 841     };
 842
 843     res
 844 }
 845
 846 pub fn trans_int_binop<'a, 'tcx: 'a>(
 847     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 848     bin_op: BinOp,
 849     lhs: CValue<'tcx>,
 850     rhs: CValue<'tcx>,
 851     out_ty: Ty<'tcx>,
 852     signed: bool,
 853 ) -> CValue<'tcx> {
 854     if bin_op != BinOp::Shl && bin_op != BinOp::Shr {
 855         assert_eq!(
 856             lhs.layout().ty,
 857             rhs.layout().ty,
 858             "int binop requires lhs and rhs of same type"
 859         );
 860     }
 861     binop_match! {
 862         fx, bin_op, signed, lhs, rhs, out_ty, "int/uint";
 863         Add (_) iadd;
 864         Sub (_) isub;
 865         Mul (_) imul;
 866         Div (false) udiv;
 867         Div (true) sdiv;
 868         Rem (false) urem;
 869         Rem (true) srem;
 870         BitXor (_) bxor;
 871         BitAnd (_) band;
 872         BitOr (_) bor;
 873         Shl (_) ishl;
 874         Shr (false) ushr;
 875         Shr (true) sshr;
 876
 877         Eq (_) icmp(Equal);
 878         Lt (false) icmp(UnsignedLessThan);
 879         Lt (true) icmp(SignedLessThan);
 880         Le (false) icmp(UnsignedLessThanOrEqual);
 881         Le (true) icmp(SignedLessThanOrEqual);
 882         Ne (_) icmp(NotEqual);
 883         Ge (false) icmp(UnsignedGreaterThanOrEqual);
 884         Ge (true) icmp(SignedGreaterThanOrEqual);
 885         Gt (false) icmp(UnsignedGreaterThan);
 886         Gt (true) icmp(SignedGreaterThan);
 887
 888         Offset (_) bug;
 889     }
 890 }
 891
 892 pub fn trans_checked_int_binop<'a, 'tcx: 'a>(
 893     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 894     bin_op: BinOp,
 895     in_lhs: CValue<'tcx>,
 896     in_rhs: CValue<'tcx>,
 897     out_ty: Ty<'tcx>,
 898     signed: bool,
 899 ) -> CValue<'tcx> {
 900     if bin_op != BinOp::Shl && bin_op != BinOp::Shr {
 901         assert_eq!(
 902             in_lhs.layout().ty,
 903             in_rhs.layout().ty,
 904             "checked int binop requires lhs and rhs of same type"
 905         );
 906     }
 907
 908     let lhs = in_lhs.load_scalar(fx);
 909     let rhs = in_rhs.load_scalar(fx);
 910     let res = match bin_op {
 911         BinOp::Add => fx.bcx.ins().iadd(lhs, rhs),
 912         BinOp::Sub => fx.bcx.ins().isub(lhs, rhs),
 913         BinOp::Mul => fx.bcx.ins().imul(lhs, rhs),
 914         BinOp::Shl => fx.bcx.ins().ishl(lhs, rhs),
 915         BinOp::Shr => {
 916             if !signed {
 917                 fx.bcx.ins().ushr(lhs, rhs)
 918             } else {
 919                 fx.bcx.ins().sshr(lhs, rhs)
 920             }
 921         }
 922         _ => bug!(
 923             "binop {:?} on checked int/uint lhs: {:?} rhs: {:?}",
 924             bin_op,
 925             in_lhs,
 926             in_rhs
 927         ),
 928     };
 929
 930     // TODO: check for overflow
 931     let has_overflow = fx.bcx.ins().iconst(types::I8, 0);
 932
 933     let out_place = CPlace::temp(fx, out_ty);
 934     let out_layout = out_place.layout();
 935     out_place.write_cvalue(fx, CValue::ByValPair(res, has_overflow, out_layout));
 936
 937     out_place.to_cvalue(fx)
 938 }
 939
 940 fn trans_float_binop<'a, 'tcx: 'a>(
 941     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 942     bin_op: BinOp,
 943     lhs: CValue<'tcx>,
 944     rhs: CValue<'tcx>,
 945     ty: Ty<'tcx>,
 946 ) -> CValue<'tcx> {
 947     let res = binop_match! {
 948         fx, bin_op, false, lhs, rhs, ty, "float";
 949         Add (_) fadd;
 950         Sub (_) fsub;
 951         Mul (_) fmul;
 952         Div (_) fdiv;
 953         Rem (_) custom(|| {
 954             assert_eq!(lhs.layout().ty, ty);
 955             assert_eq!(rhs.layout().ty, ty);
 956             match ty.sty {
 957                 ty::Float(FloatTy::F32) => fx.easy_call("fmodf", &[lhs, rhs], ty),
 958                 ty::Float(FloatTy::F64) => fx.easy_call("fmod", &[lhs, rhs], ty),
 959                 _ => bug!(),
 960             }
 961         });
 962         BitXor (_) bxor;
 963         BitAnd (_) band;
 964         BitOr (_) bor;
 965         Shl (_) bug;
 966         Shr (_) bug;
 967
 968         Eq (_) fcmp(Equal);
 969         Lt (_) fcmp(LessThan);
 970         Le (_) fcmp(LessThanOrEqual);
 971         Ne (_) fcmp(NotEqual);
 972         Ge (_) fcmp(GreaterThanOrEqual);
 973         Gt (_) fcmp(GreaterThan);
 974
 975         Offset (_) bug;
 976     };
 977
 978     res
 979 }
 980
 981 fn trans_char_binop<'a, 'tcx: 'a>(
 982     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 983     bin_op: BinOp,
 984     lhs: CValue<'tcx>,
 985     rhs: CValue<'tcx>,
 986     ty: Ty<'tcx>,
 987 ) -> CValue<'tcx> {
 988     let res = binop_match! {
 989         fx, bin_op, false, lhs, rhs, ty, "char";
 990         Add (_) bug;
 991         Sub (_) bug;
 992         Mul (_) bug;
 993         Div (_) bug;
 994         Rem (_) bug;
 995         BitXor (_) bug;
 996         BitAnd (_) bug;
 997         BitOr (_) bug;
 998         Shl (_) bug;
 999         Shr (_) bug;
1000
1001         Eq (_) icmp(Equal);
1002         Lt (_) icmp(UnsignedLessThan);
1003         Le (_) icmp(UnsignedLessThanOrEqual);
1004         Ne (_) icmp(NotEqual);
1005         Ge (_) icmp(UnsignedGreaterThanOrEqual);
1006         Gt (_) icmp(UnsignedGreaterThan);
1007
1008         Offset (_) bug;
1009     };
1010
1011     res
1012 }
1013
1014 fn trans_ptr_binop<'a, 'tcx: 'a>(
1015     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1016     bin_op: BinOp,
1017     lhs: CValue<'tcx>,
1018     rhs: CValue<'tcx>,
1019     ret_ty: Ty<'tcx>,
1020 ) -> CValue<'tcx> {
1021     match lhs.layout().ty.sty {
1022         ty::RawPtr(TypeAndMut { ty, mutbl: _ }) => {
1023             if ty.is_sized(fx.tcx.at(DUMMY_SP), ParamEnv::reveal_all()) {
1024                 binop_match! {
1025                     fx, bin_op, false, lhs, rhs, ret_ty, "ptr";
1026                     Add (_) bug;
1027                     Sub (_) bug;
1028                     Mul (_) bug;
1029                     Div (_) bug;
1030                     Rem (_) bug;
1031                     BitXor (_) bug;
1032                     BitAnd (_) bug;
1033                     BitOr (_) bug;
1034                     Shl (_) bug;
1035                     Shr (_) bug;
1036
1037                     Eq (_) icmp(Equal);
1038                     Lt (_) icmp(UnsignedLessThan);
1039                     Le (_) icmp(UnsignedLessThanOrEqual);
1040                     Ne (_) icmp(NotEqual);
1041                     Ge (_) icmp(UnsignedGreaterThanOrEqual);
1042                     Gt (_) icmp(UnsignedGreaterThan);
1043
1044                     Offset (_) iadd;
1045                 }
1046             } else {
1047                 let lhs = lhs.load_value_pair(fx).0;
1048                 let rhs = rhs.load_value_pair(fx).0;
1049                 let res = match bin_op {
1050                     BinOp::Eq => fx.bcx.ins().icmp(IntCC::Equal, lhs, rhs),
1051                     BinOp::Ne => fx.bcx.ins().icmp(IntCC::NotEqual, lhs, rhs),
1052                     _ => unimplemented!(
1053                         "trans_ptr_binop({:?}, <fat ptr>, <fat ptr>) not implemented",
1054                         bin_op
1055                     ),
1056                 };
1057
1058                 assert_eq!(fx.tcx.types.bool, ret_ty);
1059                 let ret_layout = fx.layout_of(ret_ty);
1060                 CValue::ByVal(fx.bcx.ins().bint(types::I8, res), ret_layout)
1061             }
1062         }
1063         _ => bug!("trans_ptr_binop on non ptr"),
1064     }
1065 }
1066
1067 pub fn trans_place<'a, 'tcx: 'a>(
1068     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1069     place: &Place<'tcx>,
1070 ) -> CPlace<'tcx> {
1071     match place {
1072         Place::Local(local) => fx.get_local_place(*local),
1073         Place::Promoted(promoted) => crate::constant::trans_promoted(fx, promoted.0),
1074         Place::Static(static_) => crate::constant::codegen_static_ref(fx, static_),
1075         Place::Projection(projection) => {
1076             let base = trans_place(fx, &projection.base);
1077             match projection.elem {
1078                 ProjectionElem::Deref => base.place_deref(fx),
1079                 ProjectionElem::Field(field, _ty) => base.place_field(fx, field),
1080                 ProjectionElem::Index(local) => {
1081                     let index = fx.get_local_place(local).to_cvalue(fx).load_scalar(fx);
1082                     base.place_index(fx, index)
1083                 }
1084                 ProjectionElem::ConstantIndex {
1085                     offset,
1086                     min_length: _,
1087                     from_end,
1088                 } => {
1089                     let index = if !from_end {
1090                         fx.bcx.ins().iconst(fx.pointer_type, offset as i64)
1091                     } else {
1092                         let len = codegen_array_len(fx, base);
1093                         fx.bcx.ins().iadd_imm(len, -(offset as i64))
1094                     };
1095                     base.place_index(fx, index)
1096                 }
1097                 ProjectionElem::Subslice { from, to } => unimpl!(
1098                     "projection subslice {:?} from {} to {}",
1099                     projection.base,
1100                     from,
1101                     to
1102                 ),
1103                 ProjectionElem::Downcast(_adt_def, variant) => base.downcast_variant(fx, variant),
1104             }
1105         }
1106     }
1107 }
1108
1109 pub fn trans_operand<'a, 'tcx>(
1110     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1111     operand: &Operand<'tcx>,
1112 ) -> CValue<'tcx> {
1113     match operand {
1114         Operand::Move(place) | Operand::Copy(place) => {
1115             let cplace = trans_place(fx, place);
1116             cplace.to_cvalue(fx)
1117         }
1118         Operand::Constant(const_) => crate::constant::trans_constant(fx, const_),
1119     }
1120 }