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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::traits::{ObligationCause, ObligationCauseCode};
16 use rustc::ty::{self, TyCtxt, Ty};
17 use rustc::util::nodemap::FxHashMap;
18 use require_same_types;
19
20 use syntax::abi::Abi;
21 use syntax::ast;
22 use syntax::symbol::Symbol;
23 use syntax_pos::Span;
24
25 use rustc::hir;
26
27 use std::iter;
28
29 fn equate_intrinsic_type<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
30                                    it: &hir::ForeignItem,
31                                    n_tps: usize,
32                                    abi: Abi,
33                                    inputs: Vec<Ty<'tcx>>,
34                                    output: Ty<'tcx>) {
35     let def_id = tcx.hir.local_def_id(it.id);
36
37     match it.node {
38         hir::ForeignItemFn(..) => {}
39         _ => {
40             struct_span_err!(tcx.sess, it.span, E0622,
41                              "intrinsic must be a function")
42                 .span_label(it.span, "expected a function")
43                 .emit();
44             return;
45         }
46     }
47
48     let i_n_tps = tcx.generics_of(def_id).types.len();
49     if i_n_tps != n_tps {
50         let span = match it.node {
51             hir::ForeignItemFn(_, _, ref generics) => generics.span,
52             _ => bug!()
53         };
54
55         struct_span_err!(tcx.sess, span, E0094,
56                         "intrinsic has wrong number of type \
57                         parameters: found {}, expected {}",
58                         i_n_tps, n_tps)
59             .span_label(span, format!("expected {} type parameter", n_tps))
60             .emit();
61         return;
62     }
63
64     let fty = tcx.mk_fn_ptr(ty::Binder(tcx.mk_fn_sig(
65         inputs.into_iter(),
66         output,
67         false,
68         hir::Unsafety::Unsafe,
69         abi
70     )));
71     let cause = ObligationCause::new(it.span, it.id, ObligationCauseCode::IntrinsicType);
72     require_same_types(tcx, &cause, tcx.mk_fn_ptr(tcx.fn_sig(def_id)), fty);
73 }
74
75 /// Remember to add all intrinsics here, in librustc_trans/trans/intrinsic.rs,
76 /// and in libcore/intrinsics.rs
77 pub fn check_intrinsic_type<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
78                                       it: &hir::ForeignItem) {
79     let param = |n| tcx.mk_param(n, Symbol::intern(&format!("P{}", n)));
80     let name = it.name.as_str();
81     let (n_tps, inputs, output) = if name.starts_with("atomic_") {
82         let split : Vec<&str> = name.split('_').collect();
83         assert!(split.len() >= 2, "Atomic intrinsic not correct format");
84
85         //We only care about the operation here
86         let (n_tps, inputs, output) = match split[1] {
87             "cxchg" | "cxchgweak" => (1, vec![tcx.mk_mut_ptr(param(0)),
88                                               param(0),
89                                               param(0)],
90                                       tcx.intern_tup(&[param(0), tcx.types.bool], false)),
91             "load" => (1, vec![tcx.mk_imm_ptr(param(0))],
92                        param(0)),
93             "store" => (1, vec![tcx.mk_mut_ptr(param(0)), param(0)],
94                         tcx.mk_nil()),
95
96             "xchg" | "xadd" | "xsub" | "and"  | "nand" | "or" | "xor" | "max" |
97             "min"  | "umax" | "umin" => {
98                 (1, vec![tcx.mk_mut_ptr(param(0)), param(0)],
99                  param(0))
100             }
101             "fence" | "singlethreadfence" => {
102                 (0, Vec::new(), tcx.mk_nil())
103             }
104             op => {
105                 struct_span_err!(tcx.sess, it.span, E0092,
106                       "unrecognized atomic operation function: `{}`", op)
107                   .span_label(it.span, "unrecognized atomic operation")
108                   .emit();
109                 return;
110             }
111         };
112         (n_tps, inputs, output)
113     } else if &name[..] == "abort" || &name[..] == "unreachable" {
114         (0, Vec::new(), tcx.types.never)
115     } else {
116         let (n_tps, inputs, output) = match &name[..] {
117             "breakpoint" => (0, Vec::new(), tcx.mk_nil()),
118             "size_of" |
119             "pref_align_of" | "min_align_of" => (1, Vec::new(), tcx.types.usize),
120             "size_of_val" |  "min_align_of_val" => {
121                 (1, vec![
122                     tcx.mk_imm_ref(tcx.mk_region(ty::ReLateBound(ty::DebruijnIndex::new(1),
123                                                                   ty::BrAnon(0))),
124                                     param(0))
125                  ], tcx.types.usize)
126             }
127             "rustc_peek" => (1, vec![param(0)], param(0)),
128             "init" => (1, Vec::new(), param(0)),
129             "uninit" => (1, Vec::new(), param(0)),
130             "transmute" => (2, vec![ param(0) ], param(1)),
131             "move_val_init" => {
132                 (1,
133                  vec![
134                     tcx.mk_mut_ptr(param(0)),
135                     param(0)
136                   ],
137                tcx.mk_nil())
138             }
139             "prefetch_read_data" | "prefetch_write_data" |
140             "prefetch_read_instruction" | "prefetch_write_instruction" => {
141                 (1, vec![tcx.mk_ptr(ty::TypeAndMut {
142                           ty: param(0),
143                           mutbl: hir::MutImmutable
144                          }), tcx.types.i32],
145                     tcx.mk_nil())
146             }
147             "drop_in_place" => {
148                 (1, vec![tcx.mk_mut_ptr(param(0))], tcx.mk_nil())
149             }
150             "needs_drop" => (1, Vec::new(), tcx.types.bool),
151
152             "type_name" => (1, Vec::new(), tcx.mk_static_str()),
153             "type_id" => (1, Vec::new(), tcx.types.u64),
154             "offset" | "arith_offset" => {
155               (1,
156                vec![
157                   tcx.mk_ptr(ty::TypeAndMut {
158                       ty: param(0),
159                       mutbl: hir::MutImmutable
160                   }),
161                   tcx.types.isize
162                ],
163                tcx.mk_ptr(ty::TypeAndMut {
164                    ty: param(0),
165                    mutbl: hir::MutImmutable
166                }))
167             }
168             "copy" | "copy_nonoverlapping" => {
169               (1,
170                vec![
171                   tcx.mk_ptr(ty::TypeAndMut {
172                       ty: param(0),
173                       mutbl: hir::MutImmutable
174                   }),
175                   tcx.mk_ptr(ty::TypeAndMut {
176                       ty: param(0),
177                       mutbl: hir::MutMutable
178                   }),
179                   tcx.types.usize,
180                ],
181                tcx.mk_nil())
182             }
183             "volatile_copy_memory" | "volatile_copy_nonoverlapping_memory" => {
184               (1,
185                vec![
186                   tcx.mk_ptr(ty::TypeAndMut {
187                       ty: param(0),
188                       mutbl: hir::MutMutable
189                   }),
190                   tcx.mk_ptr(ty::TypeAndMut {
191                       ty: param(0),
192                       mutbl: hir::MutImmutable
193                   }),
194                   tcx.types.usize,
195                ],
196                tcx.mk_nil())
197             }
198             "write_bytes" | "volatile_set_memory" => {
199               (1,
200                vec![
201                   tcx.mk_ptr(ty::TypeAndMut {
202                       ty: param(0),
203                       mutbl: hir::MutMutable
204                   }),
205                   tcx.types.u8,
206                   tcx.types.usize,
207                ],
208                tcx.mk_nil())
209             }
210             "sqrtf32" => (0, vec![ tcx.types.f32 ], tcx.types.f32),
211             "sqrtf64" => (0, vec![ tcx.types.f64 ], tcx.types.f64),
212             "powif32" => {
213                (0,
214                 vec![ tcx.types.f32, tcx.types.i32 ],
215                 tcx.types.f32)
216             }
217             "powif64" => {
218                (0,
219                 vec![ tcx.types.f64, tcx.types.i32 ],
220                 tcx.types.f64)
221             }
222             "sinf32" => (0, vec![ tcx.types.f32 ], tcx.types.f32),
223             "sinf64" => (0, vec![ tcx.types.f64 ], tcx.types.f64),
224             "cosf32" => (0, vec![ tcx.types.f32 ], tcx.types.f32),
225             "cosf64" => (0, vec![ tcx.types.f64 ], tcx.types.f64),
226             "powf32" => {
227                (0,
228                 vec![ tcx.types.f32, tcx.types.f32 ],
229                 tcx.types.f32)
230             }
231             "powf64" => {
232                (0,
233                 vec![ tcx.types.f64, tcx.types.f64 ],
234                 tcx.types.f64)
235             }
236             "expf32"   => (0, vec![ tcx.types.f32 ], tcx.types.f32),
237             "expf64"   => (0, vec![ tcx.types.f64 ], tcx.types.f64),
238             "exp2f32"  => (0, vec![ tcx.types.f32 ], tcx.types.f32),
239             "exp2f64"  => (0, vec![ tcx.types.f64 ], tcx.types.f64),
240             "logf32"   => (0, vec![ tcx.types.f32 ], tcx.types.f32),
241             "logf64"   => (0, vec![ tcx.types.f64 ], tcx.types.f64),
242             "log10f32" => (0, vec![ tcx.types.f32 ], tcx.types.f32),
243             "log10f64" => (0, vec![ tcx.types.f64 ], tcx.types.f64),
244             "log2f32"  => (0, vec![ tcx.types.f32 ], tcx.types.f32),
245             "log2f64"  => (0, vec![ tcx.types.f64 ], tcx.types.f64),
246             "fmaf32" => {
247                 (0,
248                  vec![ tcx.types.f32, tcx.types.f32, tcx.types.f32 ],
249                  tcx.types.f32)
250             }
251             "fmaf64" => {
252                 (0,
253                  vec![ tcx.types.f64, tcx.types.f64, tcx.types.f64 ],
254                  tcx.types.f64)
255             }
256             "fabsf32"      => (0, vec![ tcx.types.f32 ], tcx.types.f32),
257             "fabsf64"      => (0, vec![ tcx.types.f64 ], tcx.types.f64),
258             "copysignf32"  => (0, vec![ tcx.types.f32, tcx.types.f32 ], tcx.types.f32),
259             "copysignf64"  => (0, vec![ tcx.types.f64, tcx.types.f64 ], tcx.types.f64),
260             "floorf32"     => (0, vec![ tcx.types.f32 ], tcx.types.f32),
261             "floorf64"     => (0, vec![ tcx.types.f64 ], tcx.types.f64),
262             "ceilf32"      => (0, vec![ tcx.types.f32 ], tcx.types.f32),
263             "ceilf64"      => (0, vec![ tcx.types.f64 ], tcx.types.f64),
264             "truncf32"     => (0, vec![ tcx.types.f32 ], tcx.types.f32),
265             "truncf64"     => (0, vec![ tcx.types.f64 ], tcx.types.f64),
266             "rintf32"      => (0, vec![ tcx.types.f32 ], tcx.types.f32),
267             "rintf64"      => (0, vec![ tcx.types.f64 ], tcx.types.f64),
268             "nearbyintf32" => (0, vec![ tcx.types.f32 ], tcx.types.f32),
269             "nearbyintf64" => (0, vec![ tcx.types.f64 ], tcx.types.f64),
270             "roundf32"     => (0, vec![ tcx.types.f32 ], tcx.types.f32),
271             "roundf64"     => (0, vec![ tcx.types.f64 ], tcx.types.f64),
272
273             "volatile_load" =>
274                 (1, vec![ tcx.mk_imm_ptr(param(0)) ], param(0)),
275             "volatile_store" =>
276                 (1, vec![ tcx.mk_mut_ptr(param(0)), param(0) ], tcx.mk_nil()),
277
278             "ctpop" | "ctlz" | "ctlz_nonzero" | "cttz" | "cttz_nonzero" | "bswap" =>
279                 (1, vec![param(0)], param(0)),
280
281             "add_with_overflow" | "sub_with_overflow"  | "mul_with_overflow" =>
282                 (1, vec![param(0), param(0)],
283                 tcx.intern_tup(&[param(0), tcx.types.bool], false)),
284
285             "unchecked_div" | "unchecked_rem" =>
286                 (1, vec![param(0), param(0)], param(0)),
287             "unchecked_shl" | "unchecked_shr" =>
288                 (1, vec![param(0), param(0)], param(0)),
289
290             "overflowing_add" | "overflowing_sub" | "overflowing_mul" =>
291                 (1, vec![param(0), param(0)], param(0)),
292             "fadd_fast" | "fsub_fast" | "fmul_fast" | "fdiv_fast" | "frem_fast" =>
293                 (1, vec![param(0), param(0)], param(0)),
294
295             "assume" => (0, vec![tcx.types.bool], tcx.mk_nil()),
296             "likely" => (0, vec![tcx.types.bool], tcx.types.bool),
297             "unlikely" => (0, vec![tcx.types.bool], tcx.types.bool),
298
299             "discriminant_value" => (1, vec![
300                     tcx.mk_imm_ref(tcx.mk_region(ty::ReLateBound(ty::DebruijnIndex::new(1),
301                                                                   ty::BrAnon(0))),
302                                    param(0))], tcx.types.u64),
303
304             "try" => {
305                 let mut_u8 = tcx.mk_mut_ptr(tcx.types.u8);
306                 let fn_ty = ty::Binder(tcx.mk_fn_sig(
307                     iter::once(mut_u8),
308                     tcx.mk_nil(),
309                     false,
310                     hir::Unsafety::Normal,
311                     Abi::Rust,
312                 ));
313                 (0, vec![tcx.mk_fn_ptr(fn_ty), mut_u8, mut_u8], tcx.types.i32)
314             }
315
316             "align_offset" => {
317                 let ptr_ty = tcx.mk_imm_ptr(tcx.mk_nil());
318                 (0, vec![ptr_ty, tcx.types.usize], tcx.types.usize)
319             },
320
321             "nontemporal_store" => {
322                 (1, vec![ tcx.mk_mut_ptr(param(0)), param(0) ], tcx.mk_nil())
323             }
324
325             ref other => {
326                 struct_span_err!(tcx.sess, it.span, E0093,
327                                 "unrecognized intrinsic function: `{}`",
328                                 *other)
329                                 .span_label(it.span, "unrecognized intrinsic")
330                                 .emit();
331                 return;
332             }
333         };
334         (n_tps, inputs, output)
335     };
336     equate_intrinsic_type(tcx, it, n_tps, Abi::RustIntrinsic, inputs, output)
337 }
338
339 /// Type-check `extern "platform-intrinsic" { ... }` functions.
340 pub fn check_platform_intrinsic_type<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
341                                                it: &hir::ForeignItem) {
342     let param = |n| {
343         let name = Symbol::intern(&format!("P{}", n));
344         tcx.mk_param(n, name)
345     };
346
347     let def_id = tcx.hir.local_def_id(it.id);
348     let i_n_tps = tcx.generics_of(def_id).types.len();
349     let name = it.name.as_str();
350
351     let (n_tps, inputs, output) = match &*name {
352         "simd_eq" | "simd_ne" | "simd_lt" | "simd_le" | "simd_gt" | "simd_ge" => {
353             (2, vec![param(0), param(0)], param(1))
354         }
355         "simd_add" | "simd_sub" | "simd_mul" | "simd_rem" |
356         "simd_div" | "simd_shl" | "simd_shr" |
357         "simd_and" | "simd_or" | "simd_xor" => {
358             (1, vec![param(0), param(0)], param(0))
359         }
360         "simd_insert" => (2, vec![param(0), tcx.types.u32, param(1)], param(0)),
361         "simd_extract" => (2, vec![param(0), tcx.types.u32], param(1)),
362         "simd_cast" => (2, vec![param(0)], param(1)),
363         name if name.starts_with("simd_shuffle") => {
364             match name["simd_shuffle".len()..].parse() {
365                 Ok(n) => {
366                     let params = vec![param(0), param(0),
367                                       tcx.mk_array(tcx.types.u32, n)];
368                     (2, params, param(1))
369                 }
370                 Err(_) => {
371                     span_err!(tcx.sess, it.span, E0439,
372                               "invalid `simd_shuffle`, needs length: `{}`", name);
373                     return
374                 }
375             }
376         }
377         _ => {
378             match intrinsics::Intrinsic::find(&name) {
379                 Some(intr) => {
380                     // this function is a platform specific intrinsic
381                     if i_n_tps != 0 {
382                         span_err!(tcx.sess, it.span, E0440,
383                                   "platform-specific intrinsic has wrong number of type \
384                                    parameters: found {}, expected 0",
385                                   i_n_tps);
386                         return
387                     }
388
389                     let mut structural_to_nomimal = FxHashMap();
390
391                     let sig = tcx.fn_sig(def_id);
392                     let sig = tcx.no_late_bound_regions(&sig).unwrap();
393                     if intr.inputs.len() != sig.inputs().len() {
394                         span_err!(tcx.sess, it.span, E0444,
395                                   "platform-specific intrinsic has invalid number of \
396                                    arguments: found {}, expected {}",
397                                   sig.inputs().len(), intr.inputs.len());
398                         return
399                     }
400                     let input_pairs = intr.inputs.iter().zip(sig.inputs());
401                     for (i, (expected_arg, arg)) in input_pairs.enumerate() {
402                         match_intrinsic_type_to_type(tcx, &format!("argument {}", i + 1), it.span,
403                                                      &mut structural_to_nomimal, expected_arg, arg);
404                     }
405                     match_intrinsic_type_to_type(tcx, "return value", it.span,
406                                                  &mut structural_to_nomimal,
407                                                  &intr.output, sig.output());
408                     return
409                 }
410                 None => {
411                     span_err!(tcx.sess, it.span, E0441,
412                               "unrecognized platform-specific intrinsic function: `{}`", name);
413                     return;
414                 }
415             }
416         }
417     };
418
419     equate_intrinsic_type(tcx, it, n_tps, Abi::PlatformIntrinsic,
420                           inputs, output)
421 }
422
423 // walk the expected type and the actual type in lock step, checking they're
424 // the same, in a kinda-structural way, i.e. `Vector`s have to be simd structs with
425 // exactly the right element type
426 fn match_intrinsic_type_to_type<'a, 'tcx>(
427         tcx: TyCtxt<'a, 'tcx, 'tcx>,
428         position: &str,
429         span: Span,
430         structural_to_nominal: &mut FxHashMap<&'a intrinsics::Type, Ty<'tcx>>,
431         expected: &'a intrinsics::Type, t: Ty<'tcx>)
432 {
433     use intrinsics::Type::*;
434
435     let simple_error = |real: &str, expected: &str| {
436         span_err!(tcx.sess, span, E0442,
437                   "intrinsic {} has wrong type: found {}, expected {}",
438                   position, real, expected)
439     };
440
441     match *expected {
442         Void => match t.sty {
443             ty::TyTuple(ref v, _) if v.is_empty() => {},
444             _ => simple_error(&format!("`{}`", t), "()"),
445         },
446         // (The width we pass to LLVM doesn't concern the type checker.)
447         Integer(signed, bits, _llvm_width) => match (signed, bits, &t.sty) {
448             (true,  8,  &ty::TyInt(ast::IntTy::I8)) |
449             (false, 8,  &ty::TyUint(ast::UintTy::U8)) |
450             (true,  16, &ty::TyInt(ast::IntTy::I16)) |
451             (false, 16, &ty::TyUint(ast::UintTy::U16)) |
452             (true,  32, &ty::TyInt(ast::IntTy::I32)) |
453             (false, 32, &ty::TyUint(ast::UintTy::U32)) |
454             (true,  64, &ty::TyInt(ast::IntTy::I64)) |
455             (false, 64, &ty::TyUint(ast::UintTy::U64)) |
456             (true,  128, &ty::TyInt(ast::IntTy::I128)) |
457             (false, 128, &ty::TyUint(ast::UintTy::U128)) => {},
458             _ => simple_error(&format!("`{}`", t),
459                               &format!("`{}{n}`",
460                                        if signed {"i"} else {"u"},
461                                        n = bits)),
462         },
463         Float(bits) => match (bits, &t.sty) {
464             (32, &ty::TyFloat(ast::FloatTy::F32)) |
465             (64, &ty::TyFloat(ast::FloatTy::F64)) => {},
466             _ => simple_error(&format!("`{}`", t),
467                               &format!("`f{n}`", n = bits)),
468         },
469         Pointer(ref inner_expected, ref _llvm_type, const_) => {
470             match t.sty {
471                 ty::TyRawPtr(ty::TypeAndMut { ty, mutbl }) => {
472                     if (mutbl == hir::MutImmutable) != const_ {
473                         simple_error(&format!("`{}`", t),
474                                      if const_ {"const pointer"} else {"mut pointer"})
475                     }
476                     match_intrinsic_type_to_type(tcx, position, span, structural_to_nominal,
477                                                  inner_expected, ty)
478                 }
479                 _ => simple_error(&format!("`{}`", t), "raw pointer"),
480             }
481         }
482         Vector(ref inner_expected, ref _llvm_type, len) => {
483             if !t.is_simd() {
484                 simple_error(&format!("non-simd type `{}`", t), "simd type");
485                 return;
486             }
487             let t_len = t.simd_size(tcx);
488             if len as usize != t_len {
489                 simple_error(&format!("vector with length {}", t_len),
490                              &format!("length {}", len));
491                 return;
492             }
493             let t_ty = t.simd_type(tcx);
494             {
495                 // check that a given structural type always has the same an intrinsic definition
496                 let previous = structural_to_nominal.entry(expected).or_insert(t);
497                 if *previous != t {
498                     // this gets its own error code because it is non-trivial
499                     span_err!(tcx.sess, span, E0443,
500                               "intrinsic {} has wrong type: found `{}`, expected `{}` which \
501                                was used for this vector type previously in this signature",
502                               position,
503                               t,
504                               *previous);
505                     return;
506                 }
507             }
508             match_intrinsic_type_to_type(tcx,
509                                          position,
510                                          span,
511                                          structural_to_nominal,
512                                          inner_expected,
513                                          t_ty)
514         }
515         Aggregate(_flatten, ref expected_contents) => {
516             match t.sty {
517                 ty::TyTuple(contents, _) => {
518                     if contents.len() != expected_contents.len() {
519                         simple_error(&format!("tuple with length {}", contents.len()),
520                                      &format!("tuple with length {}", expected_contents.len()));
521                         return
522                     }
523                     for (e, c) in expected_contents.iter().zip(contents) {
524                         match_intrinsic_type_to_type(tcx, position, span, structural_to_nominal,
525                                                      e, c)
526                     }
527                 }
528                 _ => simple_error(&format!("`{}`", t),
529                                   "tuple"),
530             }
531         }
532     }
533 }