src/librustc_typeck/check/intrinsic.rs

   1 // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 //! Type-checking for the rust-intrinsic and platform-intrinsic
  12 //! intrinsics that the compiler exposes.
  13
  14 use intrinsics;
  15 use rustc::infer::TypeOrigin;
  16 use rustc::ty::subst::{self, Substs};
  17 use rustc::ty::FnSig;
  18 use rustc::ty::{self, Ty};
  19 use {CrateCtxt, require_same_types};
  20
  21 use std::collections::{HashMap};
  22 use syntax::abi::Abi;
  23 use syntax::ast;
  24 use syntax::parse::token;
  25 use syntax_pos::Span;
  26
  27 use rustc::hir;
  28
  29 fn equate_intrinsic_type<'a, 'tcx>(ccx: &CrateCtxt<'a, 'tcx>,
  30                                    it: &hir::ForeignItem,
  31                                    n_tps: usize,
  32                                    abi: Abi,
  33                                    inputs: Vec<ty::Ty<'tcx>>,
  34                                    output: ty::FnOutput<'tcx>) {
  35     let tcx = ccx.tcx;
  36     let def_id = tcx.map.local_def_id(it.id);
  37     let i_ty = tcx.lookup_item_type(def_id);
  38
  39     let mut substs = Substs::empty();
  40     substs.types = i_ty.generics.types.map(|def| tcx.mk_param_from_def(def));
  41
  42     let fty = tcx.mk_fn_def(def_id, tcx.mk_substs(substs),
  43                             tcx.mk_bare_fn(ty::BareFnTy {
  44         unsafety: hir::Unsafety::Unsafe,
  45         abi: abi,
  46         sig: ty::Binder(FnSig {
  47             inputs: inputs,
  48             output: output,
  49             variadic: false,
  50         }),
  51     }));
  52     let i_n_tps = i_ty.generics.types.len(subst::FnSpace);
  53     if i_n_tps != n_tps {
  54         span_err!(tcx.sess, it.span, E0094,
  55             "intrinsic has wrong number of type \
  56              parameters: found {}, expected {}",
  57              i_n_tps, n_tps);
  58     } else {
  59         require_same_types(ccx,
  60                            TypeOrigin::IntrinsicType(it.span),
  61                            i_ty.ty,
  62                            fty);
  63     }
  64 }
  65
  66 /// Remember to add all intrinsics here, in librustc_trans/trans/intrinsic.rs,
  67 /// and in libcore/intrinsics.rs
  68 pub fn check_intrinsic_type(ccx: &CrateCtxt, it: &hir::ForeignItem) {
  69     fn param<'a, 'tcx>(ccx: &CrateCtxt<'a, 'tcx>, n: u32) -> Ty<'tcx> {
  70         let name = token::intern(&format!("P{}", n));
  71         ccx.tcx.mk_param(subst::FnSpace, n, name)
  72     }
  73
  74     let tcx = ccx.tcx;
  75     let name = it.name.as_str();
  76     let (n_tps, inputs, output) = if name.starts_with("atomic_") {
  77         let split : Vec<&str> = name.split('_').collect();
  78         assert!(split.len() >= 2, "Atomic intrinsic not correct format");
  79
  80         //We only care about the operation here
  81         let (n_tps, inputs, output) = match split[1] {
  82             "cxchg" | "cxchgweak" => (1, vec!(tcx.mk_mut_ptr(param(ccx, 0)),
  83                                               param(ccx, 0),
  84                                               param(ccx, 0)),
  85                                       tcx.mk_tup(vec!(param(ccx, 0), tcx.types.bool))),
  86             "load" => (1, vec!(tcx.mk_imm_ptr(param(ccx, 0))),
  87                        param(ccx, 0)),
  88             "store" => (1, vec!(tcx.mk_mut_ptr(param(ccx, 0)), param(ccx, 0)),
  89                         tcx.mk_nil()),
  90
  91             "xchg" | "xadd" | "xsub" | "and"  | "nand" | "or" | "xor" | "max" |
  92             "min"  | "umax" | "umin" => {
  93                 (1, vec!(tcx.mk_mut_ptr(param(ccx, 0)), param(ccx, 0)),
  94                  param(ccx, 0))
  95             }
  96             "fence" | "singlethreadfence" => {
  97                 (0, Vec::new(), tcx.mk_nil())
  98             }
  99             op => {
 100                 span_err!(tcx.sess, it.span, E0092,
 101                     "unrecognized atomic operation function: `{}`", op);
 102                 return;
 103             }
 104         };
 105         (n_tps, inputs, ty::FnConverging(output))
 106     } else if &name[..] == "abort" || &name[..] == "unreachable" {
 107         (0, Vec::new(), ty::FnDiverging)
 108     } else {
 109         let (n_tps, inputs, output) = match &name[..] {
 110             "breakpoint" => (0, Vec::new(), tcx.mk_nil()),
 111             "size_of" |
 112             "pref_align_of" | "min_align_of" => (1, Vec::new(), ccx.tcx.types.usize),
 113             "size_of_val" |  "min_align_of_val" => {
 114                 (1, vec![
 115                     tcx.mk_imm_ref(tcx.mk_region(ty::ReLateBound(ty::DebruijnIndex::new(1),
 116                                                                   ty::BrAnon(0))),
 117                                     param(ccx, 0))
 118                  ], ccx.tcx.types.usize)
 119             }
 120             "rustc_peek" => (1, vec![param(ccx, 0)], param(ccx, 0)),
 121             "init" | "init_dropped" => (1, Vec::new(), param(ccx, 0)),
 122             "uninit" => (1, Vec::new(), param(ccx, 0)),
 123             "forget" => (1, vec!( param(ccx, 0) ), tcx.mk_nil()),
 124             "transmute" => (2, vec!( param(ccx, 0) ), param(ccx, 1)),
 125             "move_val_init" => {
 126                 (1,
 127                  vec!(
 128                     tcx.mk_mut_ptr(param(ccx, 0)),
 129                     param(ccx, 0)
 130                   ),
 131                tcx.mk_nil())
 132             }
 133             "drop_in_place" => {
 134                 (1, vec![tcx.mk_mut_ptr(param(ccx, 0))], tcx.mk_nil())
 135             }
 136             "needs_drop" => (1, Vec::new(), ccx.tcx.types.bool),
 137
 138             "type_name" => (1, Vec::new(), tcx.mk_static_str()),
 139             "type_id" => (1, Vec::new(), ccx.tcx.types.u64),
 140             "offset" | "arith_offset" => {
 141               (1,
 142                vec!(
 143                   tcx.mk_ptr(ty::TypeAndMut {
 144                       ty: param(ccx, 0),
 145                       mutbl: hir::MutImmutable
 146                   }),
 147                   ccx.tcx.types.isize
 148                ),
 149                tcx.mk_ptr(ty::TypeAndMut {
 150                    ty: param(ccx, 0),
 151                    mutbl: hir::MutImmutable
 152                }))
 153             }
 154             "copy" | "copy_nonoverlapping" => {
 155               (1,
 156                vec!(
 157                   tcx.mk_ptr(ty::TypeAndMut {
 158                       ty: param(ccx, 0),
 159                       mutbl: hir::MutImmutable
 160                   }),
 161                   tcx.mk_ptr(ty::TypeAndMut {
 162                       ty: param(ccx, 0),
 163                       mutbl: hir::MutMutable
 164                   }),
 165                   tcx.types.usize,
 166                ),
 167                tcx.mk_nil())
 168             }
 169             "volatile_copy_memory" | "volatile_copy_nonoverlapping_memory" => {
 170               (1,
 171                vec!(
 172                   tcx.mk_ptr(ty::TypeAndMut {
 173                       ty: param(ccx, 0),
 174                       mutbl: hir::MutMutable
 175                   }),
 176                   tcx.mk_ptr(ty::TypeAndMut {
 177                       ty: param(ccx, 0),
 178                       mutbl: hir::MutImmutable
 179                   }),
 180                   tcx.types.usize,
 181                ),
 182                tcx.mk_nil())
 183             }
 184             "write_bytes" | "volatile_set_memory" => {
 185               (1,
 186                vec!(
 187                   tcx.mk_ptr(ty::TypeAndMut {
 188                       ty: param(ccx, 0),
 189                       mutbl: hir::MutMutable
 190                   }),
 191                   tcx.types.u8,
 192                   tcx.types.usize,
 193                ),
 194                tcx.mk_nil())
 195             }
 196             "sqrtf32" => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 197             "sqrtf64" => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 198             "powif32" => {
 199                (0,
 200                 vec!( tcx.types.f32, tcx.types.i32 ),
 201                 tcx.types.f32)
 202             }
 203             "powif64" => {
 204                (0,
 205                 vec!( tcx.types.f64, tcx.types.i32 ),
 206                 tcx.types.f64)
 207             }
 208             "sinf32" => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 209             "sinf64" => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 210             "cosf32" => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 211             "cosf64" => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 212             "powf32" => {
 213                (0,
 214                 vec!( tcx.types.f32, tcx.types.f32 ),
 215                 tcx.types.f32)
 216             }
 217             "powf64" => {
 218                (0,
 219                 vec!( tcx.types.f64, tcx.types.f64 ),
 220                 tcx.types.f64)
 221             }
 222             "expf32"   => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 223             "expf64"   => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 224             "exp2f32"  => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 225             "exp2f64"  => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 226             "logf32"   => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 227             "logf64"   => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 228             "log10f32" => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 229             "log10f64" => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 230             "log2f32"  => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 231             "log2f64"  => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 232             "fmaf32" => {
 233                 (0,
 234                  vec!( tcx.types.f32, tcx.types.f32, tcx.types.f32 ),
 235                  tcx.types.f32)
 236             }
 237             "fmaf64" => {
 238                 (0,
 239                  vec!( tcx.types.f64, tcx.types.f64, tcx.types.f64 ),
 240                  tcx.types.f64)
 241             }
 242             "fabsf32"      => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 243             "fabsf64"      => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 244             "copysignf32"  => (0, vec!( tcx.types.f32, tcx.types.f32 ), tcx.types.f32),
 245             "copysignf64"  => (0, vec!( tcx.types.f64, tcx.types.f64 ), tcx.types.f64),
 246             "floorf32"     => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 247             "floorf64"     => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 248             "ceilf32"      => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 249             "ceilf64"      => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 250             "truncf32"     => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 251             "truncf64"     => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 252             "rintf32"      => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 253             "rintf64"      => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 254             "nearbyintf32" => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 255             "nearbyintf64" => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 256             "roundf32"     => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 257             "roundf64"     => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 258
 259             "volatile_load" =>
 260                 (1, vec!( tcx.mk_imm_ptr(param(ccx, 0)) ), param(ccx, 0)),
 261             "volatile_store" =>
 262                 (1, vec!( tcx.mk_mut_ptr(param(ccx, 0)), param(ccx, 0) ), tcx.mk_nil()),
 263
 264             "ctpop" | "ctlz" | "cttz" | "bswap" => (1, vec!(param(ccx, 0)), param(ccx, 0)),
 265
 266             "add_with_overflow" | "sub_with_overflow"  | "mul_with_overflow" =>
 267                 (1, vec!(param(ccx, 0), param(ccx, 0)),
 268                 tcx.mk_tup(vec!(param(ccx, 0), tcx.types.bool))),
 269
 270             "unchecked_div" | "unchecked_rem" =>
 271                 (1, vec![param(ccx, 0), param(ccx, 0)], param(ccx, 0)),
 272
 273             "overflowing_add" | "overflowing_sub" | "overflowing_mul" =>
 274                 (1, vec![param(ccx, 0), param(ccx, 0)], param(ccx, 0)),
 275             "fadd_fast" | "fsub_fast" | "fmul_fast" | "fdiv_fast" | "frem_fast" =>
 276                 (1, vec![param(ccx, 0), param(ccx, 0)], param(ccx, 0)),
 277
 278             "assume" => (0, vec![tcx.types.bool], tcx.mk_nil()),
 279
 280             "discriminant_value" => (1, vec![
 281                     tcx.mk_imm_ref(tcx.mk_region(ty::ReLateBound(ty::DebruijnIndex::new(1),
 282                                                                   ty::BrAnon(0))),
 283                                    param(ccx, 0))], tcx.types.u64),
 284
 285             "try" => {
 286                 let mut_u8 = tcx.mk_mut_ptr(tcx.types.u8);
 287                 let fn_ty = tcx.mk_bare_fn(ty::BareFnTy {
 288                     unsafety: hir::Unsafety::Normal,
 289                     abi: Abi::Rust,
 290                     sig: ty::Binder(FnSig {
 291                         inputs: vec![mut_u8],
 292                         output: ty::FnOutput::FnConverging(tcx.mk_nil()),
 293                         variadic: false,
 294                     }),
 295                 });
 296                 (0, vec![tcx.mk_fn_ptr(fn_ty), mut_u8, mut_u8], tcx.types.i32)
 297             }
 298
 299             ref other => {
 300                 struct_span_err!(tcx.sess, it.span, E0093,
 301                                 "unrecognized intrinsic function: `{}`",
 302                                 *other)
 303                                 .span_label(it.span, &format!("unrecognized intrinsic"))
 304                                 .emit();
 305                 return;
 306             }
 307         };
 308         (n_tps, inputs, ty::FnConverging(output))
 309     };
 310     equate_intrinsic_type(ccx, it, n_tps, Abi::RustIntrinsic, inputs, output)
 311 }
 312
 313 /// Type-check `extern "platform-intrinsic" { ... }` functions.
 314 pub fn check_platform_intrinsic_type(ccx: &CrateCtxt,
 315                                      it: &hir::ForeignItem) {
 316     let param = |n| {
 317         let name = token::intern(&format!("P{}", n));
 318         ccx.tcx.mk_param(subst::FnSpace, n, name)
 319     };
 320
 321     let tcx = ccx.tcx;
 322     let i_ty = tcx.lookup_item_type(tcx.map.local_def_id(it.id));
 323     let i_n_tps = i_ty.generics.types.len(subst::FnSpace);
 324     let name = it.name.as_str();
 325
 326     let (n_tps, inputs, output) = match &*name {
 327         "simd_eq" | "simd_ne" | "simd_lt" | "simd_le" | "simd_gt" | "simd_ge" => {
 328             (2, vec![param(0), param(0)], param(1))
 329         }
 330         "simd_add" | "simd_sub" | "simd_mul" |
 331         "simd_div" | "simd_shl" | "simd_shr" |
 332         "simd_and" | "simd_or" | "simd_xor" => {
 333             (1, vec![param(0), param(0)], param(0))
 334         }
 335         "simd_insert" => (2, vec![param(0), tcx.types.u32, param(1)], param(0)),
 336         "simd_extract" => (2, vec![param(0), tcx.types.u32], param(1)),
 337         "simd_cast" => (2, vec![param(0)], param(1)),
 338         name if name.starts_with("simd_shuffle") => {
 339             match name["simd_shuffle".len()..].parse() {
 340                 Ok(n) => {
 341                     let params = vec![param(0), param(0),
 342                                       tcx.mk_ty(ty::TyArray(tcx.types.u32, n))];
 343                     (2, params, param(1))
 344                 }
 345                 Err(_) => {
 346                     span_err!(tcx.sess, it.span, E0439,
 347                               "invalid `simd_shuffle`, needs length: `{}`", name);
 348                     return
 349                 }
 350             }
 351         }
 352         _ => {
 353             match intrinsics::Intrinsic::find(&name) {
 354                 Some(intr) => {
 355                     // this function is a platform specific intrinsic
 356                     if i_n_tps != 0 {
 357                         span_err!(tcx.sess, it.span, E0440,
 358                                   "platform-specific intrinsic has wrong number of type \
 359                                    parameters: found {}, expected 0",
 360                                   i_n_tps);
 361                         return
 362                     }
 363
 364                     let mut structural_to_nomimal = HashMap::new();
 365
 366                     let sig = tcx.no_late_bound_regions(i_ty.ty.fn_sig()).unwrap();
 367                     if intr.inputs.len() != sig.inputs.len() {
 368                         span_err!(tcx.sess, it.span, E0444,
 369                                   "platform-specific intrinsic has invalid number of \
 370                                    arguments: found {}, expected {}",
 371                                   intr.inputs.len(), sig.inputs.len());
 372                         return
 373                     }
 374                     let input_pairs = intr.inputs.iter().zip(&sig.inputs);
 375                     for (i, (expected_arg, arg)) in input_pairs.enumerate() {
 376                         match_intrinsic_type_to_type(ccx, &format!("argument {}", i + 1), it.span,
 377                                                      &mut structural_to_nomimal, expected_arg, arg);
 378                     }
 379                     match_intrinsic_type_to_type(ccx, "return value", it.span,
 380                                                  &mut structural_to_nomimal,
 381                                                  &intr.output, sig.output.unwrap());
 382                     return
 383                 }
 384                 None => {
 385                     span_err!(tcx.sess, it.span, E0441,
 386                               "unrecognized platform-specific intrinsic function: `{}`", name);
 387                     return;
 388                 }
 389             }
 390         }
 391     };
 392
 393     equate_intrinsic_type(ccx, it, n_tps, Abi::PlatformIntrinsic,
 394                           inputs, ty::FnConverging(output))
 395 }
 396
 397 // walk the expected type and the actual type in lock step, checking they're
 398 // the same, in a kinda-structural way, i.e. `Vector`s have to be simd structs with
 399 // exactly the right element type
 400 fn match_intrinsic_type_to_type<'tcx, 'a>(
 401         ccx: &CrateCtxt<'a, 'tcx>,
 402         position: &str,
 403         span: Span,
 404         structural_to_nominal: &mut HashMap<&'a intrinsics::Type, ty::Ty<'tcx>>,
 405         expected: &'a intrinsics::Type, t: ty::Ty<'tcx>)
 406 {
 407     use intrinsics::Type::*;
 408
 409     let simple_error = |real: &str, expected: &str| {
 410         span_err!(ccx.tcx.sess, span, E0442,
 411                   "intrinsic {} has wrong type: found {}, expected {}",
 412                   position, real, expected)
 413     };
 414
 415     match *expected {
 416         Void => match t.sty {
 417             ty::TyTuple(ref v) if v.is_empty() => {},
 418             _ => simple_error(&format!("`{}`", t), "()"),
 419         },
 420         // (The width we pass to LLVM doesn't concern the type checker.)
 421         Integer(signed, bits, _llvm_width) => match (signed, bits, &t.sty) {
 422             (true,  8,  &ty::TyInt(ast::IntTy::I8)) |
 423             (false, 8,  &ty::TyUint(ast::UintTy::U8)) |
 424             (true,  16, &ty::TyInt(ast::IntTy::I16)) |
 425             (false, 16, &ty::TyUint(ast::UintTy::U16)) |
 426             (true,  32, &ty::TyInt(ast::IntTy::I32)) |
 427             (false, 32, &ty::TyUint(ast::UintTy::U32)) |
 428             (true,  64, &ty::TyInt(ast::IntTy::I64)) |
 429             (false, 64, &ty::TyUint(ast::UintTy::U64)) => {},
 430             _ => simple_error(&format!("`{}`", t),
 431                               &format!("`{}{n}`",
 432                                        if signed {"i"} else {"u"},
 433                                        n = bits)),
 434         },
 435         Float(bits) => match (bits, &t.sty) {
 436             (32, &ty::TyFloat(ast::FloatTy::F32)) |
 437             (64, &ty::TyFloat(ast::FloatTy::F64)) => {},
 438             _ => simple_error(&format!("`{}`", t),
 439                               &format!("`f{n}`", n = bits)),
 440         },
 441         Pointer(ref inner_expected, ref _llvm_type, const_) => {
 442             match t.sty {
 443                 ty::TyRawPtr(ty::TypeAndMut { ty, mutbl }) => {
 444                     if (mutbl == hir::MutImmutable) != const_ {
 445                         simple_error(&format!("`{}`", t),
 446                                      if const_ {"const pointer"} else {"mut pointer"})
 447                     }
 448                     match_intrinsic_type_to_type(ccx, position, span, structural_to_nominal,
 449                                                  inner_expected, ty)
 450                 }
 451                 _ => simple_error(&format!("`{}`", t), "raw pointer"),
 452             }
 453         }
 454         Vector(ref inner_expected, ref _llvm_type, len) => {
 455             if !t.is_simd() {
 456                 simple_error(&format!("non-simd type `{}`", t), "simd type");
 457                 return;
 458             }
 459             let t_len = t.simd_size(ccx.tcx);
 460             if len as usize != t_len {
 461                 simple_error(&format!("vector with length {}", t_len),
 462                              &format!("length {}", len));
 463                 return;
 464             }
 465             let t_ty = t.simd_type(ccx.tcx);
 466             {
 467                 // check that a given structural type always has the same an intrinsic definition
 468                 let previous = structural_to_nominal.entry(expected).or_insert(t);
 469                 if *previous != t {
 470                     // this gets its own error code because it is non-trivial
 471                     span_err!(ccx.tcx.sess, span, E0443,
 472                               "intrinsic {} has wrong type: found `{}`, expected `{}` which \
 473                                was used for this vector type previously in this signature",
 474                               position,
 475                               t,
 476                               *previous);
 477                     return;
 478                 }
 479             }
 480             match_intrinsic_type_to_type(ccx,
 481                                          position,
 482                                          span,
 483                                          structural_to_nominal,
 484                                          inner_expected,
 485                                          t_ty)
 486         }
 487         Aggregate(_flatten, ref expected_contents) => {
 488             match t.sty {
 489                 ty::TyTuple(contents) => {
 490                     if contents.len() != expected_contents.len() {
 491                         simple_error(&format!("tuple with length {}", contents.len()),
 492                                      &format!("tuple with length {}", expected_contents.len()));
 493                         return
 494                     }
 495                     for (e, c) in expected_contents.iter().zip(contents) {
 496                         match_intrinsic_type_to_type(ccx, position, span, structural_to_nominal,
 497                                                      e, c)
 498                     }
 499                 }
 500                 _ => simple_error(&format!("`{}`", t),
 501                                   &format!("tuple")),
 502             }
 503         }
 504     }
 505 }