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 astconv::AstConv;
  15 use intrinsics;
  16 use middle::subst;
  17 use middle::ty::FnSig;
  18 use middle::ty::{self, Ty};
  19 use middle::ty::fold::TypeFolder;
  20 use {CrateCtxt, require_same_types};
  21
  22 use std::collections::{HashMap};
  23 use syntax::abi;
  24 use syntax::ast;
  25 use syntax::attr::AttrMetaMethods;
  26 use syntax::codemap::Span;
  27 use syntax::parse::token;
  28
  29 use rustc_front::hir;
  30
  31 fn equate_intrinsic_type<'a, 'tcx>(tcx: &ty::ctxt<'tcx>, it: &hir::ForeignItem,
  32                                    n_tps: usize,
  33                                    abi: abi::Abi,
  34                                    inputs: Vec<ty::Ty<'tcx>>,
  35                                    output: ty::FnOutput<'tcx>) {
  36     let fty = tcx.mk_fn(None, tcx.mk_bare_fn(ty::BareFnTy {
  37         unsafety: hir::Unsafety::Unsafe,
  38         abi: abi,
  39         sig: ty::Binder(FnSig {
  40             inputs: inputs,
  41             output: output,
  42             variadic: false,
  43         }),
  44     }));
  45     let i_ty = tcx.lookup_item_type(tcx.map.local_def_id(it.id));
  46     let i_n_tps = i_ty.generics.types.len(subst::FnSpace);
  47     if i_n_tps != n_tps {
  48         span_err!(tcx.sess, it.span, E0094,
  49             "intrinsic has wrong number of type \
  50              parameters: found {}, expected {}",
  51              i_n_tps, n_tps);
  52     } else {
  53         require_same_types(tcx,
  54                            None,
  55                            false,
  56                            it.span,
  57                            i_ty.ty,
  58                            fty,
  59                            || {
  60                 format!("intrinsic has wrong type: expected `{}`",
  61                          fty)
  62             });
  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" => (1, vec!(tcx.mk_mut_ptr(param(ccx, 0)),
  83                                 param(ccx, 0),
  84                                 param(ccx, 0)),
  85                         param(ccx, 0)),
  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             "init" | "init_dropped" => (1, Vec::new(), param(ccx, 0)),
 121             "uninit" => (1, Vec::new(), param(ccx, 0)),
 122             "forget" => (1, vec!( param(ccx, 0) ), tcx.mk_nil()),
 123             "transmute" => (2, vec!( param(ccx, 0) ), param(ccx, 1)),
 124             "move_val_init" => {
 125                 (1,
 126                  vec!(
 127                     tcx.mk_mut_ptr(param(ccx, 0)),
 128                     param(ccx, 0)
 129                   ),
 130                tcx.mk_nil())
 131             }
 132             "drop_in_place" => {
 133                 (1, vec![tcx.mk_mut_ptr(param(ccx, 0))], tcx.mk_nil())
 134             }
 135             "needs_drop" => (1, Vec::new(), ccx.tcx.types.bool),
 136
 137             "type_name" => (1, Vec::new(), tcx.mk_static_str()),
 138             "type_id" => (1, Vec::new(), ccx.tcx.types.u64),
 139             "offset" | "arith_offset" => {
 140               (1,
 141                vec!(
 142                   tcx.mk_ptr(ty::TypeAndMut {
 143                       ty: param(ccx, 0),
 144                       mutbl: hir::MutImmutable
 145                   }),
 146                   ccx.tcx.types.isize
 147                ),
 148                tcx.mk_ptr(ty::TypeAndMut {
 149                    ty: param(ccx, 0),
 150                    mutbl: hir::MutImmutable
 151                }))
 152             }
 153             "copy" | "copy_nonoverlapping" => {
 154               (1,
 155                vec!(
 156                   tcx.mk_ptr(ty::TypeAndMut {
 157                       ty: param(ccx, 0),
 158                       mutbl: hir::MutImmutable
 159                   }),
 160                   tcx.mk_ptr(ty::TypeAndMut {
 161                       ty: param(ccx, 0),
 162                       mutbl: hir::MutMutable
 163                   }),
 164                   tcx.types.usize,
 165                ),
 166                tcx.mk_nil())
 167             }
 168             "volatile_copy_memory" | "volatile_copy_nonoverlapping_memory" => {
 169               (1,
 170                vec!(
 171                   tcx.mk_ptr(ty::TypeAndMut {
 172                       ty: param(ccx, 0),
 173                       mutbl: hir::MutMutable
 174                   }),
 175                   tcx.mk_ptr(ty::TypeAndMut {
 176                       ty: param(ccx, 0),
 177                       mutbl: hir::MutImmutable
 178                   }),
 179                   tcx.types.usize,
 180                ),
 181                tcx.mk_nil())
 182             }
 183             "write_bytes" | "volatile_set_memory" => {
 184               (1,
 185                vec!(
 186                   tcx.mk_ptr(ty::TypeAndMut {
 187                       ty: param(ccx, 0),
 188                       mutbl: hir::MutMutable
 189                   }),
 190                   tcx.types.u8,
 191                   tcx.types.usize,
 192                ),
 193                tcx.mk_nil())
 194             }
 195             "sqrtf32" => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 196             "sqrtf64" => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 197             "powif32" => {
 198                (0,
 199                 vec!( tcx.types.f32, tcx.types.i32 ),
 200                 tcx.types.f32)
 201             }
 202             "powif64" => {
 203                (0,
 204                 vec!( tcx.types.f64, tcx.types.i32 ),
 205                 tcx.types.f64)
 206             }
 207             "sinf32" => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 208             "sinf64" => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 209             "cosf32" => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 210             "cosf64" => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 211             "powf32" => {
 212                (0,
 213                 vec!( tcx.types.f32, tcx.types.f32 ),
 214                 tcx.types.f32)
 215             }
 216             "powf64" => {
 217                (0,
 218                 vec!( tcx.types.f64, tcx.types.f64 ),
 219                 tcx.types.f64)
 220             }
 221             "expf32"   => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 222             "expf64"   => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 223             "exp2f32"  => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 224             "exp2f64"  => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 225             "logf32"   => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 226             "logf64"   => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 227             "log10f32" => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 228             "log10f64" => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 229             "log2f32"  => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 230             "log2f64"  => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 231             "fmaf32" => {
 232                 (0,
 233                  vec!( tcx.types.f32, tcx.types.f32, tcx.types.f32 ),
 234                  tcx.types.f32)
 235             }
 236             "fmaf64" => {
 237                 (0,
 238                  vec!( tcx.types.f64, tcx.types.f64, tcx.types.f64 ),
 239                  tcx.types.f64)
 240             }
 241             "fabsf32"      => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 242             "fabsf64"      => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 243             "copysignf32"  => (0, vec!( tcx.types.f32, tcx.types.f32 ), tcx.types.f32),
 244             "copysignf64"  => (0, vec!( tcx.types.f64, tcx.types.f64 ), tcx.types.f64),
 245             "floorf32"     => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 246             "floorf64"     => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 247             "ceilf32"      => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 248             "ceilf64"      => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 249             "truncf32"     => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 250             "truncf64"     => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 251             "rintf32"      => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 252             "rintf64"      => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 253             "nearbyintf32" => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 254             "nearbyintf64" => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 255             "roundf32"     => (0, vec!( tcx.types.f32 ), tcx.types.f32),
 256             "roundf64"     => (0, vec!( tcx.types.f64 ), tcx.types.f64),
 257
 258             "volatile_load" =>
 259                 (1, vec!( tcx.mk_imm_ptr(param(ccx, 0)) ), param(ccx, 0)),
 260             "volatile_store" =>
 261                 (1, vec!( tcx.mk_mut_ptr(param(ccx, 0)), param(ccx, 0) ), tcx.mk_nil()),
 262
 263             "ctpop" | "ctlz" | "cttz" | "bswap" => (1, vec!(param(ccx, 0)), param(ccx, 0)),
 264
 265             "add_with_overflow" | "sub_with_overflow"  | "mul_with_overflow" =>
 266                 (1, vec!(param(ccx, 0), param(ccx, 0)),
 267                 tcx.mk_tup(vec!(param(ccx, 0), tcx.types.bool))),
 268
 269             "unchecked_div" | "unchecked_rem" =>
 270                 (1, vec![param(ccx, 0), param(ccx, 0)], param(ccx, 0)),
 271
 272             "overflowing_add" | "overflowing_sub" | "overflowing_mul" =>
 273                 (1, vec![param(ccx, 0), param(ccx, 0)], param(ccx, 0)),
 274
 275             "return_address" => (0, vec![], tcx.mk_imm_ptr(tcx.types.u8)),
 276
 277             "assume" => (0, vec![tcx.types.bool], tcx.mk_nil()),
 278
 279             "discriminant_value" => (1, vec![
 280                     tcx.mk_imm_ref(tcx.mk_region(ty::ReLateBound(ty::DebruijnIndex::new(1),
 281                                                                   ty::BrAnon(0))),
 282                                    param(ccx, 0))], tcx.types.u64),
 283
 284             "try" => {
 285                 let mut_u8 = tcx.mk_mut_ptr(tcx.types.u8);
 286                 let fn_ty = ty::BareFnTy {
 287                     unsafety: hir::Unsafety::Normal,
 288                     abi: abi::Rust,
 289                     sig: ty::Binder(FnSig {
 290                         inputs: vec![mut_u8],
 291                         output: ty::FnOutput::FnConverging(tcx.mk_nil()),
 292                         variadic: false,
 293                     }),
 294                 };
 295                 let fn_ty = tcx.mk_bare_fn(fn_ty);
 296                 (0, vec![tcx.mk_fn(None, fn_ty), mut_u8], mut_u8)
 297             }
 298
 299             ref other => {
 300                 span_err!(tcx.sess, it.span, E0093,
 301                           "unrecognized intrinsic function: `{}`", *other);
 302                 return;
 303             }
 304         };
 305         (n_tps, inputs, ty::FnConverging(output))
 306     };
 307     equate_intrinsic_type(
 308         tcx,
 309         it,
 310         n_tps,
 311         abi::RustIntrinsic,
 312         inputs,
 313         output
 314         )
 315 }
 316
 317 /// Type-check `extern "platform-intrinsic" { ... }` functions.
 318 pub fn check_platform_intrinsic_type(ccx: &CrateCtxt,
 319                                      it: &hir::ForeignItem) {
 320     let param = |n| {
 321         let name = token::intern(&format!("P{}", n));
 322         ccx.tcx.mk_param(subst::FnSpace, n, name)
 323     };
 324
 325     let tcx = ccx.tcx;
 326     let i_ty = tcx.lookup_item_type(tcx.map.local_def_id(it.id));
 327     let i_n_tps = i_ty.generics.types.len(subst::FnSpace);
 328     let name = it.name.as_str();
 329
 330     let (n_tps, inputs, output) = match &*name {
 331         "simd_eq" | "simd_ne" | "simd_lt" | "simd_le" | "simd_gt" | "simd_ge" => {
 332             (2, vec![param(0), param(0)], param(1))
 333         }
 334         "simd_add" | "simd_sub" | "simd_mul" |
 335         "simd_div" | "simd_shl" | "simd_shr" |
 336         "simd_and" | "simd_or" | "simd_xor" => {
 337             (1, vec![param(0), param(0)], param(0))
 338         }
 339         "simd_insert" => (2, vec![param(0), tcx.types.u32, param(1)], param(0)),
 340         "simd_extract" => (2, vec![param(0), tcx.types.u32], param(1)),
 341         "simd_cast" => (2, vec![param(0)], param(1)),
 342         name if name.starts_with("simd_shuffle") => {
 343             match name["simd_shuffle".len()..].parse() {
 344                 Ok(n) => {
 345                     let params = vec![param(0), param(0),
 346                                       tcx.mk_ty(ty::TyArray(tcx.types.u32, n))];
 347                     (2, params, param(1))
 348                 }
 349                 Err(_) => {
 350                     span_err!(tcx.sess, it.span, E0439,
 351                               "invalid `simd_shuffle`, needs length: `{}`", name);
 352                     return
 353                 }
 354             }
 355         }
 356         _ => {
 357             match intrinsics::Intrinsic::find(tcx, &name) {
 358                 Some(intr) => {
 359                     // this function is a platform specific intrinsic
 360                     if i_n_tps != 0 {
 361                         span_err!(tcx.sess, it.span, E0440,
 362                                   "platform-specific intrinsic has wrong number of type \
 363                                    parameters: found {}, expected 0",
 364                                   i_n_tps);
 365                         return
 366                     }
 367
 368                     let mut structural_to_nomimal = HashMap::new();
 369
 370                     let sig = tcx.no_late_bound_regions(i_ty.ty.fn_sig()).unwrap();
 371                     if intr.inputs.len() != sig.inputs.len() {
 372                         span_err!(tcx.sess, it.span, E0444,
 373                                   "platform-specific intrinsic has invalid number of \
 374                                    arguments: found {}, expected {}",
 375                                   intr.inputs.len(), sig.inputs.len());
 376                         return
 377                     }
 378                     let input_pairs = intr.inputs.iter().zip(&sig.inputs);
 379                     for (i, (expected_arg, arg)) in input_pairs.enumerate() {
 380                         match_intrinsic_type_to_type(tcx, &format!("argument {}", i + 1), it.span,
 381                                                      &mut structural_to_nomimal, expected_arg, arg);
 382                     }
 383                     match_intrinsic_type_to_type(tcx, "return value", it.span,
 384                                                  &mut structural_to_nomimal,
 385                                                  &intr.output, sig.output.unwrap());
 386                     return
 387                 }
 388                 None => {
 389                     span_err!(tcx.sess, it.span, E0441,
 390                               "unrecognized platform-specific intrinsic function: `{}`", name);
 391                     return;
 392                 }
 393             }
 394         }
 395     };
 396
 397     equate_intrinsic_type(
 398         tcx,
 399         it,
 400         n_tps,
 401         abi::PlatformIntrinsic,
 402         inputs,
 403         ty::FnConverging(output)
 404         )
 405 }
 406
 407 // walk the expected type and the actual type in lock step, checking they're
 408 // the same, in a kinda-structural way, i.e. `Vector`s have to be simd structs with
 409 // exactly the right element type
 410 fn match_intrinsic_type_to_type<'tcx, 'a>(
 411         tcx: &ty::ctxt<'tcx>,
 412         position: &str,
 413         span: Span,
 414         structural_to_nominal: &mut HashMap<&'a intrinsics::Type, ty::Ty<'tcx>>,
 415         expected: &'a intrinsics::Type, t: ty::Ty<'tcx>)
 416 {
 417     use intrinsics::Type::*;
 418
 419     let simple_error = |real: &str, expected: &str| {
 420         span_err!(tcx.sess, span, E0442,
 421                   "intrinsic {} has wrong type: found {}, expected {}",
 422                   position, real, expected)
 423     };
 424
 425     match *expected {
 426         Void => match t.sty {
 427             ty::TyTuple(ref v) if v.is_empty() => {},
 428             _ => simple_error(&format!("`{}`", t), "()"),
 429         },
 430         // (The width we pass to LLVM doesn't concern the type checker.)
 431         Integer(signed, bits, _llvm_width) => match (signed, bits, &t.sty) {
 432             (true,  8,  &ty::TyInt(ast::IntTy::TyI8)) |
 433             (false, 8,  &ty::TyUint(ast::UintTy::TyU8)) |
 434             (true,  16, &ty::TyInt(ast::IntTy::TyI16)) |
 435             (false, 16, &ty::TyUint(ast::UintTy::TyU16)) |
 436             (true,  32, &ty::TyInt(ast::IntTy::TyI32)) |
 437             (false, 32, &ty::TyUint(ast::UintTy::TyU32)) |
 438             (true,  64, &ty::TyInt(ast::IntTy::TyI64)) |
 439             (false, 64, &ty::TyUint(ast::UintTy::TyU64)) => {},
 440             _ => simple_error(&format!("`{}`", t),
 441                               &format!("`{}{n}`",
 442                                        if signed {"i"} else {"u"},
 443                                        n = bits)),
 444         },
 445         Float(bits) => match (bits, &t.sty) {
 446             (32, &ty::TyFloat(ast::FloatTy::TyF32)) |
 447             (64, &ty::TyFloat(ast::FloatTy::TyF64)) => {},
 448             _ => simple_error(&format!("`{}`", t),
 449                               &format!("`f{n}`", n = bits)),
 450         },
 451         Pointer(ref inner_expected, ref _llvm_type, const_) => {
 452             match t.sty {
 453                 ty::TyRawPtr(ty::TypeAndMut { ty, mutbl }) => {
 454                     if (mutbl == hir::MutImmutable) != const_ {
 455                         simple_error(&format!("`{}`", t),
 456                                      if const_ {"const pointer"} else {"mut pointer"})
 457                     }
 458                     match_intrinsic_type_to_type(tcx, position, span, structural_to_nominal,
 459                                                  inner_expected, ty)
 460                 }
 461                 _ => simple_error(&format!("`{}`", t), "raw pointer"),
 462             }
 463         }
 464         Vector(ref inner_expected, ref _llvm_type, len) => {
 465             if !t.is_simd() {
 466                 simple_error(&format!("non-simd type `{}`", t), "simd type");
 467                 return;
 468             }
 469             let t_len = t.simd_size(tcx);
 470             if len as usize != t_len {
 471                 simple_error(&format!("vector with length {}", t_len),
 472                              &format!("length {}", len));
 473                 return;
 474             }
 475             let t_ty = t.simd_type(tcx);
 476             {
 477                 // check that a given structural type always has the same an intrinsic definition
 478                 let previous = structural_to_nominal.entry(expected).or_insert(t);
 479                 if *previous != t {
 480                     // this gets its own error code because it is non-trivial
 481                     span_err!(tcx.sess, span, E0443,
 482                               "intrinsic {} has wrong type: found `{}`, expected `{}` which \
 483                                was used for this vector type previously in this signature",
 484                               position,
 485                               t,
 486                               *previous);
 487                     return;
 488                 }
 489             }
 490             match_intrinsic_type_to_type(tcx,
 491                                          position,
 492                                          span,
 493                                          structural_to_nominal,
 494                                          inner_expected,
 495                                          t_ty)
 496         }
 497         Aggregate(_flatten, ref expected_contents) => {
 498             match t.sty {
 499                 ty::TyTuple(ref contents) => {
 500                     if contents.len() != expected_contents.len() {
 501                         simple_error(&format!("tuple with length {}", contents.len()),
 502                                      &format!("tuple with length {}", expected_contents.len()));
 503                         return
 504                     }
 505                     for (e, c) in expected_contents.iter().zip(contents) {
 506                         match_intrinsic_type_to_type(tcx, position, span, structural_to_nominal,
 507                                                      e, c)
 508                     }
 509                 }
 510                 _ => simple_error(&format!("`{}`", t),
 511                                   &format!("tuple")),
 512             }
 513         }
 514     }
 515 }