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1 | // Copyright 2012-2014 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 | //! # Translation of Expressions | |
12 | //! | |
85aaf69f SL |
13 | //! The expr module handles translation of expressions. The most general |
14 | //! translation routine is `trans()`, which will translate an expression | |
15 | //! into a datum. `trans_into()` is also available, which will translate | |
16 | //! an expression and write the result directly into memory, sometimes | |
17 | //! avoiding the need for a temporary stack slot. Finally, | |
18 | //! `trans_to_lvalue()` is available if you'd like to ensure that the | |
19 | //! result has cleanup scheduled. | |
20 | //! | |
21 | //! Internally, each of these functions dispatches to various other | |
22 | //! expression functions depending on the kind of expression. We divide | |
23 | //! up expressions into: | |
24 | //! | |
25 | //! - **Datum expressions:** Those that most naturally yield values. | |
26 | //! Examples would be `22`, `box x`, or `a + b` (when not overloaded). | |
27 | //! - **DPS expressions:** Those that most naturally write into a location | |
28 | //! in memory. Examples would be `foo()` or `Point { x: 3, y: 4 }`. | |
29 | //! - **Statement expressions:** That that do not generate a meaningful | |
30 | //! result. Examples would be `while { ... }` or `return 44`. | |
31 | //! | |
1a4d82fc JJ |
32 | //! Public entry points: |
33 | //! | |
34 | //! - `trans_into(bcx, expr, dest) -> bcx`: evaluates an expression, | |
35 | //! storing the result into `dest`. This is the preferred form, if you | |
36 | //! can manage it. | |
37 | //! | |
38 | //! - `trans(bcx, expr) -> DatumBlock`: evaluates an expression, yielding | |
39 | //! `Datum` with the result. You can then store the datum, inspect | |
40 | //! the value, etc. This may introduce temporaries if the datum is a | |
41 | //! structural type. | |
42 | //! | |
43 | //! - `trans_to_lvalue(bcx, expr, "...") -> DatumBlock`: evaluates an | |
44 | //! expression and ensures that the result has a cleanup associated with it, | |
45 | //! creating a temporary stack slot if necessary. | |
46 | //! | |
54a0048b | 47 | //! - `trans_var -> Datum`: looks up a local variable, upvar or static. |
1a4d82fc JJ |
48 | |
49 | #![allow(non_camel_case_types)] | |
50 | ||
1a4d82fc JJ |
51 | pub use self::Dest::*; |
52 | use self::lazy_binop_ty::*; | |
53 | ||
62682a34 | 54 | use llvm::{self, ValueRef, TypeKind}; |
7453a54e | 55 | use middle::const_qualif::ConstQualif; |
54a0048b SL |
56 | use rustc::hir::def::Def; |
57 | use rustc::ty::subst::Substs; | |
58 | use {_match, abi, adt, asm, base, closure, consts, controlflow}; | |
59 | use base::*; | |
60 | use build::*; | |
61 | use callee::{Callee, ArgExprs, ArgOverloadedCall, ArgOverloadedOp}; | |
62 | use cleanup::{self, CleanupMethods, DropHintMethods}; | |
63 | use common::*; | |
64 | use datum::*; | |
65 | use debuginfo::{self, DebugLoc, ToDebugLoc}; | |
54a0048b SL |
66 | use glue; |
67 | use machine; | |
68 | use tvec; | |
69 | use type_of; | |
70 | use value::Value; | |
71 | use Disr; | |
5bcae85e | 72 | use rustc::ty::adjustment::{AdjustNeverToAny, AdjustDerefRef, AdjustReifyFnPointer}; |
54a0048b SL |
73 | use rustc::ty::adjustment::{AdjustUnsafeFnPointer, AdjustMutToConstPointer}; |
74 | use rustc::ty::adjustment::CustomCoerceUnsized; | |
75 | use rustc::ty::{self, Ty, TyCtxt}; | |
76 | use rustc::ty::MethodCall; | |
77 | use rustc::ty::cast::{CastKind, CastTy}; | |
1a4d82fc | 78 | use util::common::indenter; |
54a0048b SL |
79 | use machine::{llsize_of, llsize_of_alloc}; |
80 | use type_::Type; | |
1a4d82fc | 81 | |
54a0048b | 82 | use rustc::hir; |
e9174d1e | 83 | |
3157f602 | 84 | use syntax::ast; |
c34b1796 | 85 | use syntax::parse::token::InternedString; |
3157f602 | 86 | use syntax_pos; |
54a0048b | 87 | use std::fmt; |
85aaf69f | 88 | use std::mem; |
1a4d82fc JJ |
89 | |
90 | // Destinations | |
91 | ||
92 | // These are passed around by the code generating functions to track the | |
93 | // destination of a computation's value. | |
94 | ||
c34b1796 | 95 | #[derive(Copy, Clone, PartialEq)] |
1a4d82fc JJ |
96 | pub enum Dest { |
97 | SaveIn(ValueRef), | |
98 | Ignore, | |
99 | } | |
100 | ||
54a0048b SL |
101 | impl fmt::Debug for Dest { |
102 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
1a4d82fc | 103 | match *self { |
54a0048b SL |
104 | SaveIn(v) => write!(f, "SaveIn({:?})", Value(v)), |
105 | Ignore => f.write_str("Ignore") | |
1a4d82fc JJ |
106 | } |
107 | } | |
108 | } | |
109 | ||
110 | /// This function is equivalent to `trans(bcx, expr).store_to_dest(dest)` but it may generate | |
111 | /// better optimized LLVM code. | |
112 | pub fn trans_into<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e | 113 | expr: &hir::Expr, |
1a4d82fc JJ |
114 | dest: Dest) |
115 | -> Block<'blk, 'tcx> { | |
116 | let mut bcx = bcx; | |
117 | ||
a7813a04 | 118 | expr.debug_loc().apply(bcx.fcx); |
85aaf69f | 119 | |
b039eaaf | 120 | if adjustment_required(bcx, expr) { |
1a4d82fc JJ |
121 | // use trans, which may be less efficient but |
122 | // which will perform the adjustments: | |
123 | let datum = unpack_datum!(bcx, trans(bcx, expr)); | |
85aaf69f SL |
124 | return datum.store_to_dest(bcx, dest, expr.id); |
125 | } | |
126 | ||
c34b1796 | 127 | let qualif = *bcx.tcx().const_qualif_map.borrow().get(&expr.id).unwrap(); |
7453a54e SL |
128 | if !qualif.intersects(ConstQualif::NOT_CONST | ConstQualif::NEEDS_DROP) { |
129 | if !qualif.intersects(ConstQualif::PREFER_IN_PLACE) { | |
85aaf69f | 130 | if let SaveIn(lldest) = dest { |
b039eaaf SL |
131 | match consts::get_const_expr_as_global(bcx.ccx(), expr, qualif, |
132 | bcx.fcx.param_substs, | |
133 | consts::TrueConst::No) { | |
134 | Ok(global) => { | |
135 | // Cast pointer to destination, because constants | |
136 | // have different types. | |
137 | let lldest = PointerCast(bcx, lldest, val_ty(global)); | |
138 | memcpy_ty(bcx, lldest, global, expr_ty_adjusted(bcx, expr)); | |
139 | return bcx; | |
140 | }, | |
141 | Err(consts::ConstEvalFailure::Runtime(_)) => { | |
142 | // in case const evaluation errors, translate normally | |
143 | // debug assertions catch the same errors | |
144 | // see RFC 1229 | |
145 | }, | |
146 | Err(consts::ConstEvalFailure::Compiletime(_)) => { | |
147 | return bcx; | |
148 | }, | |
149 | } | |
85aaf69f | 150 | } |
7453a54e SL |
151 | |
152 | // If we see a const here, that's because it evaluates to a type with zero size. We | |
153 | // should be able to just discard it, since const expressions are guaranteed not to | |
154 | // have side effects. This seems to be reached through tuple struct constructors being | |
155 | // passed zero-size constants. | |
156 | if let hir::ExprPath(..) = expr.node { | |
3157f602 | 157 | match bcx.tcx().expect_def(expr.id) { |
7453a54e SL |
158 | Def::Const(_) | Def::AssociatedConst(_) => { |
159 | assert!(type_is_zero_size(bcx.ccx(), bcx.tcx().node_id_to_type(expr.id))); | |
160 | return bcx; | |
161 | } | |
162 | _ => {} | |
163 | } | |
164 | } | |
165 | ||
62682a34 SL |
166 | // Even if we don't have a value to emit, and the expression |
167 | // doesn't have any side-effects, we still have to translate the | |
168 | // body of any closures. | |
169 | // FIXME: Find a better way of handling this case. | |
85aaf69f SL |
170 | } else { |
171 | // The only way we're going to see a `const` at this point is if | |
172 | // it prefers in-place instantiation, likely because it contains | |
173 | // `[x; N]` somewhere within. | |
174 | match expr.node { | |
e9174d1e | 175 | hir::ExprPath(..) => { |
3157f602 | 176 | match bcx.tcx().expect_def(expr.id) { |
7453a54e | 177 | Def::Const(did) | Def::AssociatedConst(did) => { |
54a0048b | 178 | let empty_substs = bcx.tcx().mk_substs(Substs::empty()); |
9cc50fc6 SL |
179 | let const_expr = consts::get_const_expr(bcx.ccx(), did, expr, |
180 | empty_substs); | |
85aaf69f SL |
181 | // Temporarily get cleanup scopes out of the way, |
182 | // as they require sub-expressions to be contained | |
183 | // inside the current AST scope. | |
184 | // These should record no cleanups anyways, `const` | |
185 | // can't have destructors. | |
186 | let scopes = mem::replace(&mut *bcx.fcx.scopes.borrow_mut(), | |
187 | vec![]); | |
c34b1796 AL |
188 | // Lock emitted debug locations to the location of |
189 | // the constant reference expression. | |
190 | debuginfo::with_source_location_override(bcx.fcx, | |
191 | expr.debug_loc(), | |
192 | || { | |
193 | bcx = trans_into(bcx, const_expr, dest) | |
194 | }); | |
85aaf69f SL |
195 | let scopes = mem::replace(&mut *bcx.fcx.scopes.borrow_mut(), |
196 | scopes); | |
197 | assert!(scopes.is_empty()); | |
198 | return bcx; | |
199 | } | |
200 | _ => {} | |
201 | } | |
202 | } | |
203 | _ => {} | |
204 | } | |
205 | } | |
1a4d82fc JJ |
206 | } |
207 | ||
62682a34 | 208 | debug!("trans_into() expr={:?}", expr); |
1a4d82fc JJ |
209 | |
210 | let cleanup_debug_loc = debuginfo::get_cleanup_debug_loc_for_ast_node(bcx.ccx(), | |
211 | expr.id, | |
212 | expr.span, | |
213 | false); | |
214 | bcx.fcx.push_ast_cleanup_scope(cleanup_debug_loc); | |
215 | ||
62682a34 | 216 | let kind = expr_kind(bcx.tcx(), expr); |
1a4d82fc | 217 | bcx = match kind { |
62682a34 | 218 | ExprKind::Lvalue | ExprKind::RvalueDatum => { |
1a4d82fc JJ |
219 | trans_unadjusted(bcx, expr).store_to_dest(dest, expr.id) |
220 | } | |
62682a34 | 221 | ExprKind::RvalueDps => { |
1a4d82fc JJ |
222 | trans_rvalue_dps_unadjusted(bcx, expr, dest) |
223 | } | |
62682a34 | 224 | ExprKind::RvalueStmt => { |
1a4d82fc JJ |
225 | trans_rvalue_stmt_unadjusted(bcx, expr) |
226 | } | |
227 | }; | |
228 | ||
229 | bcx.fcx.pop_and_trans_ast_cleanup_scope(bcx, expr.id) | |
230 | } | |
231 | ||
232 | /// Translates an expression, returning a datum (and new block) encapsulating the result. When | |
233 | /// possible, it is preferred to use `trans_into`, as that may avoid creating a temporary on the | |
234 | /// stack. | |
235 | pub fn trans<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e | 236 | expr: &hir::Expr) |
1a4d82fc | 237 | -> DatumBlock<'blk, 'tcx, Expr> { |
62682a34 | 238 | debug!("trans(expr={:?})", expr); |
1a4d82fc JJ |
239 | |
240 | let mut bcx = bcx; | |
241 | let fcx = bcx.fcx; | |
c34b1796 | 242 | let qualif = *bcx.tcx().const_qualif_map.borrow().get(&expr.id).unwrap(); |
7453a54e SL |
243 | let adjusted_global = !qualif.intersects(ConstQualif::NON_STATIC_BORROWS); |
244 | let global = if !qualif.intersects(ConstQualif::NOT_CONST | ConstQualif::NEEDS_DROP) { | |
b039eaaf SL |
245 | match consts::get_const_expr_as_global(bcx.ccx(), expr, qualif, |
246 | bcx.fcx.param_substs, | |
247 | consts::TrueConst::No) { | |
248 | Ok(global) => { | |
7453a54e | 249 | if qualif.intersects(ConstQualif::HAS_STATIC_BORROWS) { |
b039eaaf SL |
250 | // Is borrowed as 'static, must return lvalue. |
251 | ||
252 | // Cast pointer to global, because constants have different types. | |
253 | let const_ty = expr_ty_adjusted(bcx, expr); | |
254 | let llty = type_of::type_of(bcx.ccx(), const_ty); | |
255 | let global = PointerCast(bcx, global, llty.ptr_to()); | |
256 | let datum = Datum::new(global, const_ty, Lvalue::new("expr::trans")); | |
257 | return DatumBlock::new(bcx, datum.to_expr_datum()); | |
258 | } | |
85aaf69f | 259 | |
b039eaaf SL |
260 | // Otherwise, keep around and perform adjustments, if needed. |
261 | let const_ty = if adjusted_global { | |
262 | expr_ty_adjusted(bcx, expr) | |
263 | } else { | |
264 | expr_ty(bcx, expr) | |
265 | }; | |
85aaf69f | 266 | |
b039eaaf SL |
267 | // This could use a better heuristic. |
268 | Some(if type_is_immediate(bcx.ccx(), const_ty) { | |
269 | // Cast pointer to global, because constants have different types. | |
270 | let llty = type_of::type_of(bcx.ccx(), const_ty); | |
271 | let global = PointerCast(bcx, global, llty.ptr_to()); | |
272 | // Maybe just get the value directly, instead of loading it? | |
273 | immediate_rvalue(load_ty(bcx, global, const_ty), const_ty) | |
274 | } else { | |
275 | let scratch = alloc_ty(bcx, const_ty, "const"); | |
276 | call_lifetime_start(bcx, scratch); | |
277 | let lldest = if !const_ty.is_structural() { | |
278 | // Cast pointer to slot, because constants have different types. | |
279 | PointerCast(bcx, scratch, val_ty(global)) | |
280 | } else { | |
281 | // In this case, memcpy_ty calls llvm.memcpy after casting both | |
282 | // source and destination to i8*, so we don't need any casts. | |
283 | scratch | |
284 | }; | |
285 | memcpy_ty(bcx, lldest, global, const_ty); | |
286 | Datum::new(scratch, const_ty, Rvalue::new(ByRef)) | |
287 | }) | |
288 | }, | |
289 | Err(consts::ConstEvalFailure::Runtime(_)) => { | |
290 | // in case const evaluation errors, translate normally | |
291 | // debug assertions catch the same errors | |
292 | // see RFC 1229 | |
293 | None | |
294 | }, | |
295 | Err(consts::ConstEvalFailure::Compiletime(_)) => { | |
296 | // generate a dummy llvm value | |
297 | let const_ty = expr_ty(bcx, expr); | |
298 | let llty = type_of::type_of(bcx.ccx(), const_ty); | |
299 | let dummy = C_undef(llty.ptr_to()); | |
300 | Some(Datum::new(dummy, const_ty, Rvalue::new(ByRef))) | |
301 | }, | |
85aaf69f | 302 | } |
85aaf69f SL |
303 | } else { |
304 | None | |
305 | }; | |
1a4d82fc JJ |
306 | |
307 | let cleanup_debug_loc = debuginfo::get_cleanup_debug_loc_for_ast_node(bcx.ccx(), | |
308 | expr.id, | |
309 | expr.span, | |
310 | false); | |
311 | fcx.push_ast_cleanup_scope(cleanup_debug_loc); | |
85aaf69f SL |
312 | let datum = match global { |
313 | Some(rvalue) => rvalue.to_expr_datum(), | |
314 | None => unpack_datum!(bcx, trans_unadjusted(bcx, expr)) | |
315 | }; | |
316 | let datum = if adjusted_global { | |
317 | datum // trans::consts already performed adjustments. | |
318 | } else { | |
319 | unpack_datum!(bcx, apply_adjustments(bcx, expr, datum)) | |
320 | }; | |
1a4d82fc JJ |
321 | bcx = fcx.pop_and_trans_ast_cleanup_scope(bcx, expr.id); |
322 | return DatumBlock::new(bcx, datum); | |
323 | } | |
324 | ||
e9174d1e SL |
325 | pub fn get_meta(bcx: Block, fat_ptr: ValueRef) -> ValueRef { |
326 | StructGEP(bcx, fat_ptr, abi::FAT_PTR_EXTRA) | |
1a4d82fc JJ |
327 | } |
328 | ||
329 | pub fn get_dataptr(bcx: Block, fat_ptr: ValueRef) -> ValueRef { | |
e9174d1e | 330 | StructGEP(bcx, fat_ptr, abi::FAT_PTR_ADDR) |
85aaf69f SL |
331 | } |
332 | ||
c34b1796 AL |
333 | pub fn copy_fat_ptr(bcx: Block, src_ptr: ValueRef, dst_ptr: ValueRef) { |
334 | Store(bcx, Load(bcx, get_dataptr(bcx, src_ptr)), get_dataptr(bcx, dst_ptr)); | |
e9174d1e | 335 | Store(bcx, Load(bcx, get_meta(bcx, src_ptr)), get_meta(bcx, dst_ptr)); |
c34b1796 AL |
336 | } |
337 | ||
b039eaaf SL |
338 | fn adjustment_required<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, |
339 | expr: &hir::Expr) -> bool { | |
340 | let adjustment = match bcx.tcx().tables.borrow().adjustments.get(&expr.id).cloned() { | |
341 | None => { return false; } | |
342 | Some(adj) => adj | |
343 | }; | |
344 | ||
345 | // Don't skip a conversion from Box<T> to &T, etc. | |
346 | if bcx.tcx().is_overloaded_autoderef(expr.id, 0) { | |
347 | return true; | |
348 | } | |
349 | ||
350 | match adjustment { | |
5bcae85e | 351 | AdjustNeverToAny(..) => true, |
54a0048b | 352 | AdjustReifyFnPointer => true, |
7453a54e | 353 | AdjustUnsafeFnPointer | AdjustMutToConstPointer => { |
b039eaaf SL |
354 | // purely a type-level thing |
355 | false | |
356 | } | |
357 | AdjustDerefRef(ref adj) => { | |
358 | // We are a bit paranoid about adjustments and thus might have a re- | |
359 | // borrow here which merely derefs and then refs again (it might have | |
360 | // a different region or mutability, but we don't care here). | |
361 | !(adj.autoderefs == 1 && adj.autoref.is_some() && adj.unsize.is_none()) | |
362 | } | |
363 | } | |
364 | } | |
365 | ||
1a4d82fc JJ |
366 | /// Helper for trans that apply adjustments from `expr` to `datum`, which should be the unadjusted |
367 | /// translation of `expr`. | |
368 | fn apply_adjustments<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e | 369 | expr: &hir::Expr, |
1a4d82fc | 370 | datum: Datum<'tcx, Expr>) |
c34b1796 AL |
371 | -> DatumBlock<'blk, 'tcx, Expr> |
372 | { | |
1a4d82fc JJ |
373 | let mut bcx = bcx; |
374 | let mut datum = datum; | |
c1a9b12d | 375 | let adjustment = match bcx.tcx().tables.borrow().adjustments.get(&expr.id).cloned() { |
1a4d82fc JJ |
376 | None => { |
377 | return DatumBlock::new(bcx, datum); | |
378 | } | |
379 | Some(adj) => { adj } | |
380 | }; | |
54a0048b SL |
381 | debug!("unadjusted datum for expr {:?}: {:?} adjustment={:?}", |
382 | expr, datum, adjustment); | |
1a4d82fc | 383 | match adjustment { |
5bcae85e SL |
384 | AdjustNeverToAny(ref target) => { |
385 | let mono_target = bcx.monomorphize(target); | |
386 | let llty = type_of::type_of(bcx.ccx(), mono_target); | |
387 | let dummy = C_undef(llty.ptr_to()); | |
388 | datum = Datum::new(dummy, mono_target, Lvalue::new("never")).to_expr_datum(); | |
389 | } | |
9346a6ac | 390 | AdjustReifyFnPointer => { |
54a0048b SL |
391 | match datum.ty.sty { |
392 | ty::TyFnDef(def_id, substs, _) => { | |
393 | datum = Callee::def(bcx.ccx(), def_id, substs) | |
394 | .reify(bcx.ccx()).to_expr_datum(); | |
395 | } | |
396 | _ => { | |
397 | bug!("{} cannot be reified to a fn ptr", datum.ty) | |
398 | } | |
399 | } | |
1a4d82fc | 400 | } |
7453a54e | 401 | AdjustUnsafeFnPointer | AdjustMutToConstPointer => { |
c34b1796 AL |
402 | // purely a type-level thing |
403 | } | |
1a4d82fc | 404 | AdjustDerefRef(ref adj) => { |
9346a6ac | 405 | let skip_reborrows = if adj.autoderefs == 1 && adj.autoref.is_some() { |
1a4d82fc JJ |
406 | // We are a bit paranoid about adjustments and thus might have a re- |
407 | // borrow here which merely derefs and then refs again (it might have | |
9346a6ac AL |
408 | // a different region or mutability, but we don't care here). |
409 | match datum.ty.sty { | |
410 | // Don't skip a conversion from Box<T> to &T, etc. | |
62682a34 | 411 | ty::TyRef(..) => { |
c1a9b12d | 412 | if bcx.tcx().is_overloaded_autoderef(expr.id, 0) { |
9346a6ac AL |
413 | // Don't skip an overloaded deref. |
414 | 0 | |
415 | } else { | |
416 | 1 | |
1a4d82fc | 417 | } |
1a4d82fc | 418 | } |
9346a6ac | 419 | _ => 0 |
1a4d82fc | 420 | } |
9346a6ac AL |
421 | } else { |
422 | 0 | |
1a4d82fc JJ |
423 | }; |
424 | ||
9346a6ac | 425 | if adj.autoderefs > skip_reborrows { |
1a4d82fc JJ |
426 | // Schedule cleanup. |
427 | let lval = unpack_datum!(bcx, datum.to_lvalue_datum(bcx, "auto_deref", expr.id)); | |
9346a6ac AL |
428 | datum = unpack_datum!(bcx, deref_multiple(bcx, expr, |
429 | lval.to_expr_datum(), | |
430 | adj.autoderefs - skip_reborrows)); | |
1a4d82fc JJ |
431 | } |
432 | ||
433 | // (You might think there is a more elegant way to do this than a | |
9346a6ac AL |
434 | // skip_reborrows bool, but then you remember that the borrow checker exists). |
435 | if skip_reborrows == 0 && adj.autoref.is_some() { | |
e9174d1e | 436 | datum = unpack_datum!(bcx, auto_ref(bcx, datum, expr)); |
9346a6ac AL |
437 | } |
438 | ||
439 | if let Some(target) = adj.unsize { | |
d9579d0f AL |
440 | // We do not arrange cleanup ourselves; if we already are an |
441 | // L-value, then cleanup will have already been scheduled (and | |
442 | // the `datum.to_rvalue_datum` call below will emit code to zero | |
443 | // the drop flag when moving out of the L-value). If we are an | |
444 | // R-value, then we do not need to schedule cleanup. | |
445 | let source_datum = unpack_datum!(bcx, | |
446 | datum.to_rvalue_datum(bcx, "__coerce_source")); | |
447 | ||
448 | let target = bcx.monomorphize(&target); | |
d9579d0f | 449 | |
e9174d1e SL |
450 | let scratch = alloc_ty(bcx, target, "__coerce_target"); |
451 | call_lifetime_start(bcx, scratch); | |
d9579d0f AL |
452 | let target_datum = Datum::new(scratch, target, |
453 | Rvalue::new(ByRef)); | |
454 | bcx = coerce_unsized(bcx, expr.span, source_datum, target_datum); | |
455 | datum = Datum::new(scratch, target, | |
456 | RvalueExpr(Rvalue::new(ByRef))); | |
1a4d82fc JJ |
457 | } |
458 | } | |
459 | } | |
54a0048b | 460 | debug!("after adjustments, datum={:?}", datum); |
d9579d0f AL |
461 | DatumBlock::new(bcx, datum) |
462 | } | |
1a4d82fc | 463 | |
d9579d0f | 464 | fn coerce_unsized<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, |
3157f602 | 465 | span: syntax_pos::Span, |
d9579d0f AL |
466 | source: Datum<'tcx, Rvalue>, |
467 | target: Datum<'tcx, Rvalue>) | |
468 | -> Block<'blk, 'tcx> { | |
469 | let mut bcx = bcx; | |
54a0048b | 470 | debug!("coerce_unsized({:?} -> {:?})", source, target); |
d9579d0f AL |
471 | |
472 | match (&source.ty.sty, &target.ty.sty) { | |
62682a34 | 473 | (&ty::TyBox(a), &ty::TyBox(b)) | |
c1a9b12d SL |
474 | (&ty::TyRef(_, ty::TypeAndMut { ty: a, .. }), |
475 | &ty::TyRef(_, ty::TypeAndMut { ty: b, .. })) | | |
476 | (&ty::TyRef(_, ty::TypeAndMut { ty: a, .. }), | |
477 | &ty::TyRawPtr(ty::TypeAndMut { ty: b, .. })) | | |
478 | (&ty::TyRawPtr(ty::TypeAndMut { ty: a, .. }), | |
479 | &ty::TyRawPtr(ty::TypeAndMut { ty: b, .. })) => { | |
d9579d0f AL |
480 | let (inner_source, inner_target) = (a, b); |
481 | ||
482 | let (base, old_info) = if !type_is_sized(bcx.tcx(), inner_source) { | |
483 | // Normally, the source is a thin pointer and we are | |
484 | // adding extra info to make a fat pointer. The exception | |
485 | // is when we are upcasting an existing object fat pointer | |
486 | // to use a different vtable. In that case, we want to | |
487 | // load out the original data pointer so we can repackage | |
488 | // it. | |
489 | (Load(bcx, get_dataptr(bcx, source.val)), | |
e9174d1e | 490 | Some(Load(bcx, get_meta(bcx, source.val)))) |
d9579d0f AL |
491 | } else { |
492 | let val = if source.kind.is_by_ref() { | |
493 | load_ty(bcx, source.val, source.ty) | |
494 | } else { | |
495 | source.val | |
496 | }; | |
497 | (val, None) | |
498 | }; | |
1a4d82fc | 499 | |
54a0048b | 500 | let info = unsized_info(bcx.ccx(), inner_source, inner_target, old_info); |
d9579d0f AL |
501 | |
502 | // Compute the base pointer. This doesn't change the pointer value, | |
503 | // but merely its type. | |
504 | let ptr_ty = type_of::in_memory_type_of(bcx.ccx(), inner_target).ptr_to(); | |
505 | let base = PointerCast(bcx, base, ptr_ty); | |
506 | ||
507 | Store(bcx, base, get_dataptr(bcx, target.val)); | |
e9174d1e | 508 | Store(bcx, info, get_meta(bcx, target.val)); |
9346a6ac | 509 | } |
1a4d82fc | 510 | |
d9579d0f | 511 | // This can be extended to enums and tuples in the future. |
62682a34 SL |
512 | // (&ty::TyEnum(def_id_a, _), &ty::TyEnum(def_id_b, _)) | |
513 | (&ty::TyStruct(def_id_a, _), &ty::TyStruct(def_id_b, _)) => { | |
d9579d0f AL |
514 | assert_eq!(def_id_a, def_id_b); |
515 | ||
516 | // The target is already by-ref because it's to be written to. | |
517 | let source = unpack_datum!(bcx, source.to_ref_datum(bcx)); | |
518 | assert!(target.kind.is_by_ref()); | |
9346a6ac | 519 | |
a7813a04 XL |
520 | let kind = custom_coerce_unsize_info(bcx.ccx().shared(), |
521 | source.ty, | |
522 | target.ty); | |
1a4d82fc | 523 | |
d9579d0f AL |
524 | let repr_source = adt::represent_type(bcx.ccx(), source.ty); |
525 | let src_fields = match &*repr_source { | |
526 | &adt::Repr::Univariant(ref s, _) => &s.fields, | |
54a0048b SL |
527 | _ => span_bug!(span, |
528 | "Non univariant struct? (repr_source: {:?})", | |
529 | repr_source), | |
d9579d0f AL |
530 | }; |
531 | let repr_target = adt::represent_type(bcx.ccx(), target.ty); | |
532 | let target_fields = match &*repr_target { | |
533 | &adt::Repr::Univariant(ref s, _) => &s.fields, | |
54a0048b SL |
534 | _ => span_bug!(span, |
535 | "Non univariant struct? (repr_target: {:?})", | |
536 | repr_target), | |
d9579d0f | 537 | }; |
1a4d82fc | 538 | |
d9579d0f | 539 | let coerce_index = match kind { |
e9174d1e | 540 | CustomCoerceUnsized::Struct(i) => i |
d9579d0f AL |
541 | }; |
542 | assert!(coerce_index < src_fields.len() && src_fields.len() == target_fields.len()); | |
543 | ||
92a42be0 SL |
544 | let source_val = adt::MaybeSizedValue::sized(source.val); |
545 | let target_val = adt::MaybeSizedValue::sized(target.val); | |
546 | ||
62682a34 | 547 | let iter = src_fields.iter().zip(target_fields).enumerate(); |
d9579d0f | 548 | for (i, (src_ty, target_ty)) in iter { |
9cc50fc6 SL |
549 | let ll_source = adt::trans_field_ptr(bcx, &repr_source, source_val, Disr(0), i); |
550 | let ll_target = adt::trans_field_ptr(bcx, &repr_target, target_val, Disr(0), i); | |
d9579d0f AL |
551 | |
552 | // If this is the field we need to coerce, recurse on it. | |
553 | if i == coerce_index { | |
554 | coerce_unsized(bcx, span, | |
555 | Datum::new(ll_source, src_ty, | |
556 | Rvalue::new(ByRef)), | |
557 | Datum::new(ll_target, target_ty, | |
558 | Rvalue::new(ByRef))); | |
559 | } else { | |
560 | // Otherwise, simply copy the data from the source. | |
b039eaaf | 561 | assert!(src_ty.is_phantom_data() || src_ty == target_ty); |
d9579d0f AL |
562 | memcpy_ty(bcx, ll_target, ll_source, src_ty); |
563 | } | |
564 | } | |
565 | } | |
54a0048b SL |
566 | _ => bug!("coerce_unsized: invalid coercion {:?} -> {:?}", |
567 | source.ty, | |
568 | target.ty) | |
1a4d82fc | 569 | } |
d9579d0f | 570 | bcx |
1a4d82fc JJ |
571 | } |
572 | ||
573 | /// Translates an expression in "lvalue" mode -- meaning that it returns a reference to the memory | |
574 | /// that the expr represents. | |
575 | /// | |
576 | /// If this expression is an rvalue, this implies introducing a temporary. In other words, | |
577 | /// something like `x().f` is translated into roughly the equivalent of | |
578 | /// | |
579 | /// { tmp = x(); tmp.f } | |
580 | pub fn trans_to_lvalue<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e | 581 | expr: &hir::Expr, |
1a4d82fc JJ |
582 | name: &str) |
583 | -> DatumBlock<'blk, 'tcx, Lvalue> { | |
584 | let mut bcx = bcx; | |
585 | let datum = unpack_datum!(bcx, trans(bcx, expr)); | |
586 | return datum.to_lvalue_datum(bcx, name, expr.id); | |
587 | } | |
588 | ||
589 | /// A version of `trans` that ignores adjustments. You almost certainly do not want to call this | |
590 | /// directly. | |
591 | fn trans_unadjusted<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e | 592 | expr: &hir::Expr) |
1a4d82fc JJ |
593 | -> DatumBlock<'blk, 'tcx, Expr> { |
594 | let mut bcx = bcx; | |
595 | ||
62682a34 | 596 | debug!("trans_unadjusted(expr={:?})", expr); |
1a4d82fc JJ |
597 | let _indenter = indenter(); |
598 | ||
a7813a04 | 599 | expr.debug_loc().apply(bcx.fcx); |
1a4d82fc | 600 | |
62682a34 SL |
601 | return match expr_kind(bcx.tcx(), expr) { |
602 | ExprKind::Lvalue | ExprKind::RvalueDatum => { | |
1a4d82fc JJ |
603 | let datum = unpack_datum!(bcx, { |
604 | trans_datum_unadjusted(bcx, expr) | |
605 | }); | |
606 | ||
607 | DatumBlock {bcx: bcx, datum: datum} | |
608 | } | |
609 | ||
62682a34 | 610 | ExprKind::RvalueStmt => { |
1a4d82fc JJ |
611 | bcx = trans_rvalue_stmt_unadjusted(bcx, expr); |
612 | nil(bcx, expr_ty(bcx, expr)) | |
613 | } | |
614 | ||
62682a34 | 615 | ExprKind::RvalueDps => { |
1a4d82fc JJ |
616 | let ty = expr_ty(bcx, expr); |
617 | if type_is_zero_size(bcx.ccx(), ty) { | |
618 | bcx = trans_rvalue_dps_unadjusted(bcx, expr, Ignore); | |
619 | nil(bcx, ty) | |
620 | } else { | |
621 | let scratch = rvalue_scratch_datum(bcx, ty, ""); | |
622 | bcx = trans_rvalue_dps_unadjusted( | |
623 | bcx, expr, SaveIn(scratch.val)); | |
624 | ||
625 | // Note: this is not obviously a good idea. It causes | |
626 | // immediate values to be loaded immediately after a | |
627 | // return from a call or other similar expression, | |
628 | // which in turn leads to alloca's having shorter | |
629 | // lifetimes and hence larger stack frames. However, | |
630 | // in turn it can lead to more register pressure. | |
631 | // Still, in practice it seems to increase | |
632 | // performance, since we have fewer problems with | |
633 | // morestack churn. | |
634 | let scratch = unpack_datum!( | |
635 | bcx, scratch.to_appropriate_datum(bcx)); | |
636 | ||
637 | DatumBlock::new(bcx, scratch.to_expr_datum()) | |
638 | } | |
639 | } | |
640 | }; | |
641 | ||
642 | fn nil<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, ty: Ty<'tcx>) | |
643 | -> DatumBlock<'blk, 'tcx, Expr> { | |
644 | let llval = C_undef(type_of::type_of(bcx.ccx(), ty)); | |
645 | let datum = immediate_rvalue(llval, ty); | |
646 | DatumBlock::new(bcx, datum.to_expr_datum()) | |
647 | } | |
648 | } | |
649 | ||
650 | fn trans_datum_unadjusted<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e | 651 | expr: &hir::Expr) |
1a4d82fc JJ |
652 | -> DatumBlock<'blk, 'tcx, Expr> { |
653 | let mut bcx = bcx; | |
654 | let fcx = bcx.fcx; | |
655 | let _icx = push_ctxt("trans_datum_unadjusted"); | |
656 | ||
657 | match expr.node { | |
9cc50fc6 | 658 | hir::ExprType(ref e, _) => { |
7453a54e | 659 | trans(bcx, &e) |
9cc50fc6 | 660 | } |
e9174d1e | 661 | hir::ExprPath(..) => { |
3157f602 | 662 | let var = trans_var(bcx, bcx.tcx().expect_def(expr.id)); |
54a0048b | 663 | DatumBlock::new(bcx, var.to_expr_datum()) |
1a4d82fc | 664 | } |
b039eaaf | 665 | hir::ExprField(ref base, name) => { |
7453a54e | 666 | trans_rec_field(bcx, &base, name.node) |
1a4d82fc | 667 | } |
e9174d1e | 668 | hir::ExprTupField(ref base, idx) => { |
7453a54e | 669 | trans_rec_tup_field(bcx, &base, idx.node) |
1a4d82fc | 670 | } |
e9174d1e | 671 | hir::ExprIndex(ref base, ref idx) => { |
7453a54e | 672 | trans_index(bcx, expr, &base, &idx, MethodCall::expr(expr.id)) |
1a4d82fc | 673 | } |
b039eaaf | 674 | hir::ExprBox(ref contents) => { |
1a4d82fc JJ |
675 | // Special case for `Box<T>` |
676 | let box_ty = expr_ty(bcx, expr); | |
7453a54e | 677 | let contents_ty = expr_ty(bcx, &contents); |
1a4d82fc | 678 | match box_ty.sty { |
62682a34 | 679 | ty::TyBox(..) => { |
7453a54e | 680 | trans_uniq_expr(bcx, expr, box_ty, &contents, contents_ty) |
1a4d82fc | 681 | } |
54a0048b SL |
682 | _ => span_bug!(expr.span, |
683 | "expected unique box") | |
1a4d82fc JJ |
684 | } |
685 | ||
686 | } | |
7453a54e | 687 | hir::ExprLit(ref lit) => trans_immediate_lit(bcx, expr, &lit), |
e9174d1e | 688 | hir::ExprBinary(op, ref lhs, ref rhs) => { |
7453a54e | 689 | trans_binary(bcx, expr, op, &lhs, &rhs) |
1a4d82fc | 690 | } |
e9174d1e | 691 | hir::ExprUnary(op, ref x) => { |
7453a54e | 692 | trans_unary(bcx, expr, op, &x) |
1a4d82fc | 693 | } |
e9174d1e | 694 | hir::ExprAddrOf(_, ref x) => { |
1a4d82fc | 695 | match x.node { |
e9174d1e | 696 | hir::ExprRepeat(..) | hir::ExprVec(..) => { |
1a4d82fc JJ |
697 | // Special case for slices. |
698 | let cleanup_debug_loc = | |
699 | debuginfo::get_cleanup_debug_loc_for_ast_node(bcx.ccx(), | |
700 | x.id, | |
701 | x.span, | |
702 | false); | |
703 | fcx.push_ast_cleanup_scope(cleanup_debug_loc); | |
704 | let datum = unpack_datum!( | |
7453a54e | 705 | bcx, tvec::trans_slice_vec(bcx, expr, &x)); |
1a4d82fc JJ |
706 | bcx = fcx.pop_and_trans_ast_cleanup_scope(bcx, x.id); |
707 | DatumBlock::new(bcx, datum) | |
708 | } | |
709 | _ => { | |
7453a54e | 710 | trans_addr_of(bcx, expr, &x) |
1a4d82fc JJ |
711 | } |
712 | } | |
713 | } | |
e9174d1e | 714 | hir::ExprCast(ref val, _) => { |
1a4d82fc | 715 | // Datum output mode means this is a scalar cast: |
7453a54e | 716 | trans_imm_cast(bcx, &val, expr.id) |
1a4d82fc JJ |
717 | } |
718 | _ => { | |
54a0048b | 719 | span_bug!( |
1a4d82fc | 720 | expr.span, |
54a0048b SL |
721 | "trans_rvalue_datum_unadjusted reached \ |
722 | fall-through case: {:?}", | |
723 | expr.node); | |
1a4d82fc JJ |
724 | } |
725 | } | |
726 | } | |
727 | ||
728 | fn trans_field<'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>, | |
e9174d1e | 729 | base: &hir::Expr, |
1a4d82fc JJ |
730 | get_idx: F) |
731 | -> DatumBlock<'blk, 'tcx, Expr> where | |
a7813a04 | 732 | F: FnOnce(TyCtxt<'blk, 'tcx, 'tcx>, &VariantInfo<'tcx>) -> usize, |
1a4d82fc JJ |
733 | { |
734 | let mut bcx = bcx; | |
735 | let _icx = push_ctxt("trans_rec_field"); | |
736 | ||
737 | let base_datum = unpack_datum!(bcx, trans_to_lvalue(bcx, base, "field")); | |
c34b1796 | 738 | let bare_ty = base_datum.ty; |
1a4d82fc | 739 | let repr = adt::represent_type(bcx.ccx(), bare_ty); |
e9174d1e | 740 | let vinfo = VariantInfo::from_ty(bcx.tcx(), bare_ty, None); |
1a4d82fc | 741 | |
e9174d1e SL |
742 | let ix = get_idx(bcx.tcx(), &vinfo); |
743 | let d = base_datum.get_element( | |
744 | bcx, | |
745 | vinfo.fields[ix].1, | |
92a42be0 | 746 | |srcval| { |
7453a54e | 747 | adt::trans_field_ptr(bcx, &repr, srcval, vinfo.discr, ix) |
92a42be0 | 748 | }); |
1a4d82fc | 749 | |
e9174d1e SL |
750 | if type_is_sized(bcx.tcx(), d.ty) { |
751 | DatumBlock { datum: d.to_expr_datum(), bcx: bcx } | |
752 | } else { | |
753 | let scratch = rvalue_scratch_datum(bcx, d.ty, ""); | |
754 | Store(bcx, d.val, get_dataptr(bcx, scratch.val)); | |
755 | let info = Load(bcx, get_meta(bcx, base_datum.val)); | |
756 | Store(bcx, info, get_meta(bcx, scratch.val)); | |
757 | ||
758 | // Always generate an lvalue datum, because this pointer doesn't own | |
759 | // the data and cleanup is scheduled elsewhere. | |
760 | DatumBlock::new(bcx, Datum::new(scratch.val, scratch.ty, LvalueExpr(d.kind))) | |
761 | } | |
1a4d82fc JJ |
762 | } |
763 | ||
764 | /// Translates `base.field`. | |
765 | fn trans_rec_field<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e | 766 | base: &hir::Expr, |
9346a6ac | 767 | field: ast::Name) |
1a4d82fc | 768 | -> DatumBlock<'blk, 'tcx, Expr> { |
e9174d1e | 769 | trans_field(bcx, base, |_, vinfo| vinfo.field_index(field)) |
1a4d82fc JJ |
770 | } |
771 | ||
772 | /// Translates `base.<idx>`. | |
773 | fn trans_rec_tup_field<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e | 774 | base: &hir::Expr, |
c34b1796 | 775 | idx: usize) |
1a4d82fc JJ |
776 | -> DatumBlock<'blk, 'tcx, Expr> { |
777 | trans_field(bcx, base, |_, _| idx) | |
778 | } | |
779 | ||
780 | fn trans_index<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e SL |
781 | index_expr: &hir::Expr, |
782 | base: &hir::Expr, | |
783 | idx: &hir::Expr, | |
1a4d82fc JJ |
784 | method_call: MethodCall) |
785 | -> DatumBlock<'blk, 'tcx, Expr> { | |
786 | //! Translates `base[idx]`. | |
787 | ||
788 | let _icx = push_ctxt("trans_index"); | |
789 | let ccx = bcx.ccx(); | |
790 | let mut bcx = bcx; | |
791 | ||
85aaf69f SL |
792 | let index_expr_debug_loc = index_expr.debug_loc(); |
793 | ||
1a4d82fc | 794 | // Check for overloaded index. |
54a0048b SL |
795 | let method = ccx.tcx().tables.borrow().method_map.get(&method_call).cloned(); |
796 | let elt_datum = match method { | |
797 | Some(method) => { | |
798 | let method_ty = monomorphize_type(bcx, method.ty); | |
1a4d82fc JJ |
799 | |
800 | let base_datum = unpack_datum!(bcx, trans(bcx, base)); | |
801 | ||
802 | // Translate index expression. | |
803 | let ix_datum = unpack_datum!(bcx, trans(bcx, idx)); | |
804 | ||
805 | let ref_ty = // invoked methods have LB regions instantiated: | |
5bcae85e | 806 | bcx.tcx().no_late_bound_regions(&method_ty.fn_ret()).unwrap(); |
e9174d1e | 807 | let elt_ty = match ref_ty.builtin_deref(true, ty::NoPreference) { |
1a4d82fc | 808 | None => { |
54a0048b SL |
809 | span_bug!(index_expr.span, |
810 | "index method didn't return a \ | |
811 | dereferenceable type?!") | |
1a4d82fc JJ |
812 | } |
813 | Some(elt_tm) => elt_tm.ty, | |
814 | }; | |
815 | ||
54a0048b SL |
816 | // Overloaded. Invoke the index() method, which basically |
817 | // yields a `&T` pointer. We can then proceed down the | |
818 | // normal path (below) to dereference that `&T`. | |
1a4d82fc | 819 | let scratch = rvalue_scratch_datum(bcx, ref_ty, "overloaded_index_elt"); |
54a0048b SL |
820 | |
821 | bcx = Callee::method(bcx, method) | |
822 | .call(bcx, index_expr_debug_loc, | |
823 | ArgOverloadedOp(base_datum, Some(ix_datum)), | |
824 | Some(SaveIn(scratch.val))).bcx; | |
825 | ||
1a4d82fc | 826 | let datum = scratch.to_expr_datum(); |
c1a9b12d | 827 | let lval = Lvalue::new("expr::trans_index overload"); |
1a4d82fc | 828 | if type_is_sized(bcx.tcx(), elt_ty) { |
c1a9b12d | 829 | Datum::new(datum.to_llscalarish(bcx), elt_ty, LvalueExpr(lval)) |
1a4d82fc | 830 | } else { |
c1a9b12d | 831 | Datum::new(datum.val, elt_ty, LvalueExpr(lval)) |
1a4d82fc JJ |
832 | } |
833 | } | |
834 | None => { | |
835 | let base_datum = unpack_datum!(bcx, trans_to_lvalue(bcx, | |
836 | base, | |
837 | "index")); | |
838 | ||
839 | // Translate index expression and cast to a suitable LLVM integer. | |
840 | // Rust is less strict than LLVM in this regard. | |
841 | let ix_datum = unpack_datum!(bcx, trans(bcx, idx)); | |
842 | let ix_val = ix_datum.to_llscalarish(bcx); | |
843 | let ix_size = machine::llbitsize_of_real(bcx.ccx(), | |
844 | val_ty(ix_val)); | |
845 | let int_size = machine::llbitsize_of_real(bcx.ccx(), | |
846 | ccx.int_type()); | |
847 | let ix_val = { | |
848 | if ix_size < int_size { | |
c1a9b12d | 849 | if expr_ty(bcx, idx).is_signed() { |
1a4d82fc JJ |
850 | SExt(bcx, ix_val, ccx.int_type()) |
851 | } else { ZExt(bcx, ix_val, ccx.int_type()) } | |
852 | } else if ix_size > int_size { | |
853 | Trunc(bcx, ix_val, ccx.int_type()) | |
854 | } else { | |
855 | ix_val | |
856 | } | |
857 | }; | |
858 | ||
c1a9b12d | 859 | let unit_ty = base_datum.ty.sequence_element_type(bcx.tcx()); |
1a4d82fc JJ |
860 | |
861 | let (base, len) = base_datum.get_vec_base_and_len(bcx); | |
862 | ||
54a0048b SL |
863 | debug!("trans_index: base {:?}", Value(base)); |
864 | debug!("trans_index: len {:?}", Value(len)); | |
1a4d82fc | 865 | |
85aaf69f SL |
866 | let bounds_check = ICmp(bcx, |
867 | llvm::IntUGE, | |
868 | ix_val, | |
869 | len, | |
870 | index_expr_debug_loc); | |
1a4d82fc JJ |
871 | let expect = ccx.get_intrinsic(&("llvm.expect.i1")); |
872 | let expected = Call(bcx, | |
873 | expect, | |
874 | &[bounds_check, C_bool(ccx, false)], | |
85aaf69f | 875 | index_expr_debug_loc); |
1a4d82fc JJ |
876 | bcx = with_cond(bcx, expected, |bcx| { |
877 | controlflow::trans_fail_bounds_check(bcx, | |
85aaf69f | 878 | expr_info(index_expr), |
1a4d82fc JJ |
879 | ix_val, |
880 | len) | |
881 | }); | |
882 | let elt = InBoundsGEP(bcx, base, &[ix_val]); | |
c34b1796 | 883 | let elt = PointerCast(bcx, elt, type_of::type_of(ccx, unit_ty).ptr_to()); |
c1a9b12d SL |
884 | let lval = Lvalue::new("expr::trans_index fallback"); |
885 | Datum::new(elt, unit_ty, LvalueExpr(lval)) | |
1a4d82fc JJ |
886 | } |
887 | }; | |
888 | ||
889 | DatumBlock::new(bcx, elt_datum) | |
890 | } | |
891 | ||
54a0048b SL |
892 | /// Translates a reference to a variable. |
893 | pub fn trans_var<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, def: Def) | |
894 | -> Datum<'tcx, Lvalue> { | |
1a4d82fc | 895 | |
1a4d82fc | 896 | match def { |
54a0048b SL |
897 | Def::Static(did, _) => consts::get_static(bcx.ccx(), did), |
898 | Def::Upvar(_, nid, _, _) => { | |
899 | // Can't move upvars, so this is never a ZeroMemLastUse. | |
900 | let local_ty = node_id_type(bcx, nid); | |
901 | let lval = Lvalue::new_with_hint("expr::trans_var (upvar)", | |
902 | bcx, nid, HintKind::ZeroAndMaintain); | |
903 | match bcx.fcx.llupvars.borrow().get(&nid) { | |
904 | Some(&val) => Datum::new(val, local_ty, lval), | |
905 | None => { | |
906 | bug!("trans_var: no llval for upvar {} found", nid); | |
907 | } | |
908 | } | |
1a4d82fc | 909 | } |
54a0048b SL |
910 | Def::Local(_, nid) => { |
911 | let datum = match bcx.fcx.lllocals.borrow().get(&nid) { | |
912 | Some(&v) => v, | |
913 | None => { | |
914 | bug!("trans_var: no datum for local/arg {} found", nid); | |
915 | } | |
916 | }; | |
917 | debug!("take_local(nid={}, v={:?}, ty={})", | |
918 | nid, Value(datum.val), datum.ty); | |
919 | datum | |
1a4d82fc | 920 | } |
54a0048b | 921 | _ => bug!("{:?} should not reach expr::trans_var", def) |
1a4d82fc JJ |
922 | } |
923 | } | |
924 | ||
925 | fn trans_rvalue_stmt_unadjusted<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e | 926 | expr: &hir::Expr) |
1a4d82fc JJ |
927 | -> Block<'blk, 'tcx> { |
928 | let mut bcx = bcx; | |
929 | let _icx = push_ctxt("trans_rvalue_stmt"); | |
930 | ||
931 | if bcx.unreachable.get() { | |
932 | return bcx; | |
933 | } | |
934 | ||
a7813a04 | 935 | expr.debug_loc().apply(bcx.fcx); |
1a4d82fc JJ |
936 | |
937 | match expr.node { | |
e9174d1e | 938 | hir::ExprBreak(label_opt) => { |
a7813a04 | 939 | controlflow::trans_break(bcx, expr, label_opt.map(|l| l.node)) |
1a4d82fc | 940 | } |
9cc50fc6 | 941 | hir::ExprType(ref e, _) => { |
7453a54e | 942 | trans_into(bcx, &e, Ignore) |
9cc50fc6 | 943 | } |
e9174d1e | 944 | hir::ExprAgain(label_opt) => { |
a7813a04 | 945 | controlflow::trans_cont(bcx, expr, label_opt.map(|l| l.node)) |
1a4d82fc | 946 | } |
e9174d1e | 947 | hir::ExprRet(ref ex) => { |
1a4d82fc JJ |
948 | // Check to see if the return expression itself is reachable. |
949 | // This can occur when the inner expression contains a return | |
950 | let reachable = if let Some(ref cfg) = bcx.fcx.cfg { | |
951 | cfg.node_is_reachable(expr.id) | |
952 | } else { | |
953 | true | |
954 | }; | |
955 | ||
956 | if reachable { | |
85aaf69f | 957 | controlflow::trans_ret(bcx, expr, ex.as_ref().map(|e| &**e)) |
1a4d82fc JJ |
958 | } else { |
959 | // If it's not reachable, just translate the inner expression | |
960 | // directly. This avoids having to manage a return slot when | |
961 | // it won't actually be used anyway. | |
962 | if let &Some(ref x) = ex { | |
7453a54e | 963 | bcx = trans_into(bcx, &x, Ignore); |
1a4d82fc JJ |
964 | } |
965 | // Mark the end of the block as unreachable. Once we get to | |
966 | // a return expression, there's no more we should be doing | |
967 | // after this. | |
968 | Unreachable(bcx); | |
969 | bcx | |
970 | } | |
971 | } | |
e9174d1e | 972 | hir::ExprWhile(ref cond, ref body, _) => { |
7453a54e | 973 | controlflow::trans_while(bcx, expr, &cond, &body) |
1a4d82fc | 974 | } |
e9174d1e | 975 | hir::ExprLoop(ref body, _) => { |
7453a54e | 976 | controlflow::trans_loop(bcx, expr, &body) |
1a4d82fc | 977 | } |
e9174d1e | 978 | hir::ExprAssign(ref dst, ref src) => { |
7453a54e SL |
979 | let src_datum = unpack_datum!(bcx, trans(bcx, &src)); |
980 | let dst_datum = unpack_datum!(bcx, trans_to_lvalue(bcx, &dst, "assign")); | |
1a4d82fc | 981 | |
c34b1796 | 982 | if bcx.fcx.type_needs_drop(dst_datum.ty) { |
1a4d82fc JJ |
983 | // If there are destructors involved, make sure we |
984 | // are copying from an rvalue, since that cannot possible | |
985 | // alias an lvalue. We are concerned about code like: | |
986 | // | |
987 | // a = a | |
988 | // | |
989 | // but also | |
990 | // | |
991 | // a = a.b | |
992 | // | |
993 | // where e.g. a : Option<Foo> and a.b : | |
994 | // Option<Foo>. In that case, freeing `a` before the | |
995 | // assignment may also free `a.b`! | |
996 | // | |
997 | // We could avoid this intermediary with some analysis | |
998 | // to determine whether `dst` may possibly own `src`. | |
a7813a04 | 999 | expr.debug_loc().apply(bcx.fcx); |
1a4d82fc JJ |
1000 | let src_datum = unpack_datum!( |
1001 | bcx, src_datum.to_rvalue_datum(bcx, "ExprAssign")); | |
c1a9b12d SL |
1002 | let opt_hint_datum = dst_datum.kind.drop_flag_info.hint_datum(bcx); |
1003 | let opt_hint_val = opt_hint_datum.map(|d|d.to_value()); | |
1004 | ||
1005 | // 1. Drop the data at the destination, passing the | |
1006 | // drop-hint in case the lvalue has already been | |
1007 | // dropped or moved. | |
1008 | bcx = glue::drop_ty_core(bcx, | |
1009 | dst_datum.val, | |
1010 | dst_datum.ty, | |
1011 | expr.debug_loc(), | |
1012 | false, | |
1013 | opt_hint_val); | |
1014 | ||
1015 | // 2. We are overwriting the destination; ensure that | |
1016 | // its drop-hint (if any) says "initialized." | |
1017 | if let Some(hint_val) = opt_hint_val { | |
1018 | let hint_llval = hint_val.value(); | |
e9174d1e | 1019 | let drop_needed = C_u8(bcx.fcx.ccx, adt::DTOR_NEEDED_HINT); |
c1a9b12d SL |
1020 | Store(bcx, drop_needed, hint_llval); |
1021 | } | |
1a4d82fc JJ |
1022 | src_datum.store_to(bcx, dst_datum.val) |
1023 | } else { | |
1024 | src_datum.store_to(bcx, dst_datum.val) | |
1025 | } | |
1026 | } | |
e9174d1e | 1027 | hir::ExprAssignOp(op, ref dst, ref src) => { |
54a0048b SL |
1028 | let method = bcx.tcx().tables |
1029 | .borrow() | |
1030 | .method_map | |
1031 | .get(&MethodCall::expr(expr.id)).cloned(); | |
b039eaaf | 1032 | |
54a0048b | 1033 | if let Some(method) = method { |
7453a54e SL |
1034 | let dst = unpack_datum!(bcx, trans(bcx, &dst)); |
1035 | let src_datum = unpack_datum!(bcx, trans(bcx, &src)); | |
54a0048b SL |
1036 | |
1037 | Callee::method(bcx, method) | |
1038 | .call(bcx, expr.debug_loc(), | |
1039 | ArgOverloadedOp(dst, Some(src_datum)), None).bcx | |
b039eaaf | 1040 | } else { |
7453a54e | 1041 | trans_assign_op(bcx, expr, op, &dst, &src) |
b039eaaf | 1042 | } |
1a4d82fc | 1043 | } |
54a0048b SL |
1044 | hir::ExprInlineAsm(ref a, ref outputs, ref inputs) => { |
1045 | let outputs = outputs.iter().map(|output| { | |
1046 | let out_datum = unpack_datum!(bcx, trans(bcx, output)); | |
1047 | unpack_datum!(bcx, out_datum.to_lvalue_datum(bcx, "out", expr.id)) | |
1048 | }).collect(); | |
1049 | let inputs = inputs.iter().map(|input| { | |
1050 | let input = unpack_datum!(bcx, trans(bcx, input)); | |
1051 | let input = unpack_datum!(bcx, input.to_rvalue_datum(bcx, "in")); | |
1052 | input.to_llscalarish(bcx) | |
1053 | }).collect(); | |
1054 | asm::trans_inline_asm(bcx, a, outputs, inputs); | |
1055 | bcx | |
1a4d82fc JJ |
1056 | } |
1057 | _ => { | |
54a0048b | 1058 | span_bug!( |
1a4d82fc | 1059 | expr.span, |
54a0048b SL |
1060 | "trans_rvalue_stmt_unadjusted reached \ |
1061 | fall-through case: {:?}", | |
1062 | expr.node); | |
1a4d82fc JJ |
1063 | } |
1064 | } | |
1065 | } | |
1066 | ||
1067 | fn trans_rvalue_dps_unadjusted<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e | 1068 | expr: &hir::Expr, |
1a4d82fc JJ |
1069 | dest: Dest) |
1070 | -> Block<'blk, 'tcx> { | |
1071 | let _icx = push_ctxt("trans_rvalue_dps_unadjusted"); | |
1072 | let mut bcx = bcx; | |
1a4d82fc | 1073 | |
a7813a04 | 1074 | expr.debug_loc().apply(bcx.fcx); |
1a4d82fc | 1075 | |
54a0048b SL |
1076 | // Entry into the method table if this is an overloaded call/op. |
1077 | let method_call = MethodCall::expr(expr.id); | |
1078 | ||
1a4d82fc | 1079 | match expr.node { |
9cc50fc6 | 1080 | hir::ExprType(ref e, _) => { |
7453a54e | 1081 | trans_into(bcx, &e, dest) |
9cc50fc6 | 1082 | } |
e9174d1e | 1083 | hir::ExprPath(..) => { |
3157f602 | 1084 | trans_def_dps_unadjusted(bcx, expr, bcx.tcx().expect_def(expr.id), dest) |
1a4d82fc | 1085 | } |
e9174d1e | 1086 | hir::ExprIf(ref cond, ref thn, ref els) => { |
7453a54e | 1087 | controlflow::trans_if(bcx, expr.id, &cond, &thn, els.as_ref().map(|e| &**e), dest) |
1a4d82fc | 1088 | } |
e9174d1e | 1089 | hir::ExprMatch(ref discr, ref arms, _) => { |
7453a54e | 1090 | _match::trans_match(bcx, expr, &discr, &arms[..], dest) |
1a4d82fc | 1091 | } |
e9174d1e | 1092 | hir::ExprBlock(ref blk) => { |
7453a54e | 1093 | controlflow::trans_block(bcx, &blk, dest) |
1a4d82fc | 1094 | } |
e9174d1e | 1095 | hir::ExprStruct(_, ref fields, ref base) => { |
1a4d82fc | 1096 | trans_struct(bcx, |
85aaf69f | 1097 | &fields[..], |
1a4d82fc JJ |
1098 | base.as_ref().map(|e| &**e), |
1099 | expr.span, | |
1100 | expr.id, | |
1101 | node_id_type(bcx, expr.id), | |
1102 | dest) | |
1103 | } | |
e9174d1e SL |
1104 | hir::ExprTup(ref args) => { |
1105 | let numbered_fields: Vec<(usize, &hir::Expr)> = | |
1a4d82fc JJ |
1106 | args.iter().enumerate().map(|(i, arg)| (i, &**arg)).collect(); |
1107 | trans_adt(bcx, | |
1108 | expr_ty(bcx, expr), | |
9cc50fc6 | 1109 | Disr(0), |
85aaf69f | 1110 | &numbered_fields[..], |
1a4d82fc JJ |
1111 | None, |
1112 | dest, | |
85aaf69f | 1113 | expr.debug_loc()) |
1a4d82fc | 1114 | } |
e9174d1e | 1115 | hir::ExprLit(ref lit) => { |
1a4d82fc | 1116 | match lit.node { |
7453a54e | 1117 | ast::LitKind::Str(ref s, _) => { |
1a4d82fc JJ |
1118 | tvec::trans_lit_str(bcx, expr, (*s).clone(), dest) |
1119 | } | |
1120 | _ => { | |
54a0048b SL |
1121 | span_bug!(expr.span, |
1122 | "trans_rvalue_dps_unadjusted shouldn't be \ | |
1123 | translating this type of literal") | |
1a4d82fc JJ |
1124 | } |
1125 | } | |
1126 | } | |
e9174d1e | 1127 | hir::ExprVec(..) | hir::ExprRepeat(..) => { |
1a4d82fc JJ |
1128 | tvec::trans_fixed_vstore(bcx, expr, dest) |
1129 | } | |
a7813a04 | 1130 | hir::ExprClosure(_, ref decl, ref body, _) => { |
85aaf69f SL |
1131 | let dest = match dest { |
1132 | SaveIn(lldest) => closure::Dest::SaveIn(bcx, lldest), | |
1133 | Ignore => closure::Dest::Ignore(bcx.ccx()) | |
1134 | }; | |
b039eaaf SL |
1135 | |
1136 | // NB. To get the id of the closure, we don't use | |
1137 | // `local_def_id(id)`, but rather we extract the closure | |
1138 | // def-id from the expr's type. This is because this may | |
1139 | // be an inlined expression from another crate, and we | |
1140 | // want to get the ORIGINAL closure def-id, since that is | |
1141 | // the key we need to find the closure-kind and | |
1142 | // closure-type etc. | |
1143 | let (def_id, substs) = match expr_ty(bcx, expr).sty { | |
a7813a04 | 1144 | ty::TyClosure(def_id, substs) => (def_id, substs), |
c1a9b12d | 1145 | ref t => |
54a0048b | 1146 | span_bug!( |
c1a9b12d | 1147 | expr.span, |
54a0048b | 1148 | "closure expr without closure type: {:?}", t), |
c1a9b12d | 1149 | }; |
b039eaaf | 1150 | |
9cc50fc6 SL |
1151 | closure::trans_closure_expr(dest, |
1152 | decl, | |
1153 | body, | |
1154 | expr.id, | |
1155 | def_id, | |
54a0048b | 1156 | substs).unwrap_or(bcx) |
1a4d82fc | 1157 | } |
e9174d1e | 1158 | hir::ExprCall(ref f, ref args) => { |
54a0048b SL |
1159 | let method = bcx.tcx().tables.borrow().method_map.get(&method_call).cloned(); |
1160 | let (callee, args) = if let Some(method) = method { | |
1161 | let mut all_args = vec![&**f]; | |
1162 | all_args.extend(args.iter().map(|e| &**e)); | |
1163 | ||
1164 | (Callee::method(bcx, method), ArgOverloadedCall(all_args)) | |
1a4d82fc | 1165 | } else { |
54a0048b SL |
1166 | let f = unpack_datum!(bcx, trans(bcx, f)); |
1167 | (match f.ty.sty { | |
1168 | ty::TyFnDef(def_id, substs, _) => { | |
1169 | Callee::def(bcx.ccx(), def_id, substs) | |
1170 | } | |
1171 | ty::TyFnPtr(_) => { | |
1172 | let f = unpack_datum!(bcx, | |
1173 | f.to_rvalue_datum(bcx, "callee")); | |
1174 | Callee::ptr(f) | |
1175 | } | |
1176 | _ => { | |
1177 | span_bug!(expr.span, | |
1178 | "type of callee is not a fn: {}", f.ty); | |
1179 | } | |
1180 | }, ArgExprs(&args)) | |
1181 | }; | |
1182 | callee.call(bcx, expr.debug_loc(), args, Some(dest)).bcx | |
1a4d82fc | 1183 | } |
e9174d1e | 1184 | hir::ExprMethodCall(_, _, ref args) => { |
54a0048b SL |
1185 | Callee::method_call(bcx, method_call) |
1186 | .call(bcx, expr.debug_loc(), ArgExprs(&args), Some(dest)).bcx | |
1a4d82fc | 1187 | } |
54a0048b | 1188 | hir::ExprBinary(op, ref lhs, ref rhs_expr) => { |
1a4d82fc | 1189 | // if not overloaded, would be RvalueDatumExpr |
7453a54e | 1190 | let lhs = unpack_datum!(bcx, trans(bcx, &lhs)); |
54a0048b SL |
1191 | let mut rhs = unpack_datum!(bcx, trans(bcx, &rhs_expr)); |
1192 | if !op.node.is_by_value() { | |
1193 | rhs = unpack_datum!(bcx, auto_ref(bcx, rhs, rhs_expr)); | |
1194 | } | |
1195 | ||
1196 | Callee::method_call(bcx, method_call) | |
1197 | .call(bcx, expr.debug_loc(), | |
1198 | ArgOverloadedOp(lhs, Some(rhs)), Some(dest)).bcx | |
1a4d82fc | 1199 | } |
54a0048b | 1200 | hir::ExprUnary(_, ref subexpr) => { |
1a4d82fc | 1201 | // if not overloaded, would be RvalueDatumExpr |
7453a54e | 1202 | let arg = unpack_datum!(bcx, trans(bcx, &subexpr)); |
54a0048b SL |
1203 | |
1204 | Callee::method_call(bcx, method_call) | |
1205 | .call(bcx, expr.debug_loc(), | |
1206 | ArgOverloadedOp(arg, None), Some(dest)).bcx | |
1a4d82fc | 1207 | } |
e9174d1e | 1208 | hir::ExprCast(..) => { |
c34b1796 | 1209 | // Trait casts used to come this way, now they should be coercions. |
54a0048b | 1210 | span_bug!(expr.span, "DPS expr_cast (residual trait cast?)") |
1a4d82fc | 1211 | } |
b039eaaf | 1212 | hir::ExprAssignOp(op, _, _) => { |
54a0048b | 1213 | span_bug!( |
b039eaaf | 1214 | expr.span, |
54a0048b SL |
1215 | "augmented assignment `{}=` should always be a rvalue_stmt", |
1216 | op.node.as_str()) | |
1a4d82fc JJ |
1217 | } |
1218 | _ => { | |
54a0048b | 1219 | span_bug!( |
1a4d82fc | 1220 | expr.span, |
54a0048b SL |
1221 | "trans_rvalue_dps_unadjusted reached fall-through \ |
1222 | case: {:?}", | |
1223 | expr.node); | |
1a4d82fc JJ |
1224 | } |
1225 | } | |
1226 | } | |
1227 | ||
1228 | fn trans_def_dps_unadjusted<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e | 1229 | ref_expr: &hir::Expr, |
7453a54e | 1230 | def: Def, |
1a4d82fc JJ |
1231 | dest: Dest) |
1232 | -> Block<'blk, 'tcx> { | |
1233 | let _icx = push_ctxt("trans_def_dps_unadjusted"); | |
1234 | ||
1235 | let lldest = match dest { | |
1236 | SaveIn(lldest) => lldest, | |
1237 | Ignore => { return bcx; } | |
1238 | }; | |
1239 | ||
54a0048b SL |
1240 | let ty = expr_ty(bcx, ref_expr); |
1241 | if let ty::TyFnDef(..) = ty.sty { | |
1242 | // Zero-sized function or ctor. | |
1243 | return bcx; | |
1244 | } | |
1245 | ||
1a4d82fc | 1246 | match def { |
7453a54e | 1247 | Def::Variant(tid, vid) => { |
e9174d1e | 1248 | let variant = bcx.tcx().lookup_adt_def(tid).variant_with_id(vid); |
54a0048b SL |
1249 | // Nullary variant. |
1250 | let ty = expr_ty(bcx, ref_expr); | |
1251 | let repr = adt::represent_type(bcx.ccx(), ty); | |
1252 | adt::trans_set_discr(bcx, &repr, lldest, Disr::from(variant.disr_val)); | |
1253 | bcx | |
1a4d82fc | 1254 | } |
7453a54e | 1255 | Def::Struct(..) => { |
1a4d82fc | 1256 | match ty.sty { |
e9174d1e | 1257 | ty::TyStruct(def, _) if def.has_dtor() => { |
1a4d82fc | 1258 | let repr = adt::represent_type(bcx.ccx(), ty); |
7453a54e | 1259 | adt::trans_set_discr(bcx, &repr, lldest, Disr(0)); |
1a4d82fc JJ |
1260 | } |
1261 | _ => {} | |
1262 | } | |
1263 | bcx | |
1264 | } | |
1265 | _ => { | |
54a0048b SL |
1266 | span_bug!(ref_expr.span, |
1267 | "Non-DPS def {:?} referened by {}", | |
1268 | def, bcx.node_id_to_string(ref_expr.id)); | |
1a4d82fc JJ |
1269 | } |
1270 | } | |
1271 | } | |
1272 | ||
1a4d82fc | 1273 | fn trans_struct<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, |
e9174d1e SL |
1274 | fields: &[hir::Field], |
1275 | base: Option<&hir::Expr>, | |
3157f602 | 1276 | expr_span: syntax_pos::Span, |
1a4d82fc JJ |
1277 | expr_id: ast::NodeId, |
1278 | ty: Ty<'tcx>, | |
1279 | dest: Dest) -> Block<'blk, 'tcx> { | |
1280 | let _icx = push_ctxt("trans_rec"); | |
1281 | ||
1282 | let tcx = bcx.tcx(); | |
e9174d1e SL |
1283 | let vinfo = VariantInfo::of_node(tcx, ty, expr_id); |
1284 | ||
1285 | let mut need_base = vec![true; vinfo.fields.len()]; | |
1286 | ||
1287 | let numbered_fields = fields.iter().map(|field| { | |
b039eaaf | 1288 | let pos = vinfo.field_index(field.name.node); |
e9174d1e SL |
1289 | need_base[pos] = false; |
1290 | (pos, &*field.expr) | |
1291 | }).collect::<Vec<_>>(); | |
1292 | ||
1293 | let optbase = match base { | |
1294 | Some(base_expr) => { | |
1295 | let mut leftovers = Vec::new(); | |
1296 | for (i, b) in need_base.iter().enumerate() { | |
1297 | if *b { | |
1298 | leftovers.push((i, vinfo.fields[i].1)); | |
1a4d82fc | 1299 | } |
1a4d82fc | 1300 | } |
e9174d1e SL |
1301 | Some(StructBaseInfo {expr: base_expr, |
1302 | fields: leftovers }) | |
1303 | } | |
1304 | None => { | |
1305 | if need_base.iter().any(|b| *b) { | |
54a0048b | 1306 | span_bug!(expr_span, "missing fields and no base expr") |
1a4d82fc | 1307 | } |
e9174d1e SL |
1308 | None |
1309 | } | |
1310 | }; | |
1a4d82fc | 1311 | |
e9174d1e SL |
1312 | trans_adt(bcx, |
1313 | ty, | |
1314 | vinfo.discr, | |
1315 | &numbered_fields, | |
1316 | optbase, | |
1317 | dest, | |
1318 | DebugLoc::At(expr_id, expr_span)) | |
1a4d82fc JJ |
1319 | } |
1320 | ||
1321 | /// Information that `trans_adt` needs in order to fill in the fields | |
1322 | /// of a struct copied from a base struct (e.g., from an expression | |
1323 | /// like `Foo { a: b, ..base }`. | |
1324 | /// | |
1325 | /// Note that `fields` may be empty; the base expression must always be | |
1326 | /// evaluated for side-effects. | |
1327 | pub struct StructBaseInfo<'a, 'tcx> { | |
1328 | /// The base expression; will be evaluated after all explicit fields. | |
e9174d1e | 1329 | expr: &'a hir::Expr, |
1a4d82fc | 1330 | /// The indices of fields to copy paired with their types. |
c34b1796 | 1331 | fields: Vec<(usize, Ty<'tcx>)> |
1a4d82fc JJ |
1332 | } |
1333 | ||
1334 | /// Constructs an ADT instance: | |
1335 | /// | |
1336 | /// - `fields` should be a list of field indices paired with the | |
1337 | /// expression to store into that field. The initializers will be | |
1338 | /// evaluated in the order specified by `fields`. | |
1339 | /// | |
1340 | /// - `optbase` contains information on the base struct (if any) from | |
1341 | /// which remaining fields are copied; see comments on `StructBaseInfo`. | |
1342 | pub fn trans_adt<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>, | |
1343 | ty: Ty<'tcx>, | |
9cc50fc6 | 1344 | discr: Disr, |
e9174d1e | 1345 | fields: &[(usize, &hir::Expr)], |
1a4d82fc JJ |
1346 | optbase: Option<StructBaseInfo<'a, 'tcx>>, |
1347 | dest: Dest, | |
85aaf69f | 1348 | debug_location: DebugLoc) |
1a4d82fc JJ |
1349 | -> Block<'blk, 'tcx> { |
1350 | let _icx = push_ctxt("trans_adt"); | |
1351 | let fcx = bcx.fcx; | |
1352 | let repr = adt::represent_type(bcx.ccx(), ty); | |
1353 | ||
85aaf69f | 1354 | debug_location.apply(bcx.fcx); |
1a4d82fc JJ |
1355 | |
1356 | // If we don't care about the result, just make a | |
1357 | // temporary stack slot | |
1358 | let addr = match dest { | |
1359 | SaveIn(pos) => pos, | |
e9174d1e SL |
1360 | Ignore => { |
1361 | let llresult = alloc_ty(bcx, ty, "temp"); | |
1362 | call_lifetime_start(bcx, llresult); | |
1363 | llresult | |
1364 | } | |
1a4d82fc JJ |
1365 | }; |
1366 | ||
9cc50fc6 SL |
1367 | debug!("trans_adt"); |
1368 | ||
1a4d82fc JJ |
1369 | // This scope holds intermediates that must be cleaned should |
1370 | // panic occur before the ADT as a whole is ready. | |
1371 | let custom_cleanup_scope = fcx.push_custom_cleanup_scope(); | |
1372 | ||
e9174d1e | 1373 | if ty.is_simd() { |
c34b1796 AL |
1374 | // Issue 23112: The original logic appeared vulnerable to same |
1375 | // order-of-eval bug. But, SIMD values are tuple-structs; | |
1376 | // i.e. functional record update (FRU) syntax is unavailable. | |
1377 | // | |
1378 | // To be safe, double-check that we did not get here via FRU. | |
1379 | assert!(optbase.is_none()); | |
1380 | ||
1a4d82fc JJ |
1381 | // This is the constructor of a SIMD type, such types are |
1382 | // always primitive machine types and so do not have a | |
1383 | // destructor or require any clean-up. | |
1384 | let llty = type_of::type_of(bcx.ccx(), ty); | |
1385 | ||
1386 | // keep a vector as a register, and running through the field | |
1387 | // `insertelement`ing them directly into that register | |
1388 | // (i.e. avoid GEPi and `store`s to an alloca) . | |
1389 | let mut vec_val = C_undef(llty); | |
1390 | ||
85aaf69f | 1391 | for &(i, ref e) in fields { |
7453a54e | 1392 | let block_datum = trans(bcx, &e); |
1a4d82fc JJ |
1393 | bcx = block_datum.bcx; |
1394 | let position = C_uint(bcx.ccx(), i); | |
1395 | let value = block_datum.datum.to_llscalarish(bcx); | |
1396 | vec_val = InsertElement(bcx, vec_val, value, position); | |
1397 | } | |
1398 | Store(bcx, vec_val, addr); | |
c34b1796 AL |
1399 | } else if let Some(base) = optbase { |
1400 | // Issue 23112: If there is a base, then order-of-eval | |
1401 | // requires field expressions eval'ed before base expression. | |
1402 | ||
1403 | // First, trans field expressions to temporary scratch values. | |
1404 | let scratch_vals: Vec<_> = fields.iter().map(|&(i, ref e)| { | |
7453a54e | 1405 | let datum = unpack_datum!(bcx, trans(bcx, &e)); |
c34b1796 AL |
1406 | (i, datum) |
1407 | }).collect(); | |
1408 | ||
1409 | debug_location.apply(bcx.fcx); | |
1410 | ||
1411 | // Second, trans the base to the dest. | |
9cc50fc6 | 1412 | assert_eq!(discr, Disr(0)); |
c34b1796 | 1413 | |
92a42be0 | 1414 | let addr = adt::MaybeSizedValue::sized(addr); |
7453a54e | 1415 | match expr_kind(bcx.tcx(), &base.expr) { |
62682a34 | 1416 | ExprKind::RvalueDps | ExprKind::RvalueDatum if !bcx.fcx.type_needs_drop(ty) => { |
7453a54e | 1417 | bcx = trans_into(bcx, &base.expr, SaveIn(addr.value)); |
c34b1796 | 1418 | }, |
62682a34 | 1419 | ExprKind::RvalueStmt => { |
54a0048b | 1420 | bug!("unexpected expr kind for struct base expr") |
62682a34 | 1421 | } |
c34b1796 | 1422 | _ => { |
7453a54e | 1423 | let base_datum = unpack_datum!(bcx, trans_to_lvalue(bcx, &base.expr, "base")); |
c34b1796 AL |
1424 | for &(i, t) in &base.fields { |
1425 | let datum = base_datum.get_element( | |
7453a54e | 1426 | bcx, t, |srcval| adt::trans_field_ptr(bcx, &repr, srcval, discr, i)); |
c34b1796 | 1427 | assert!(type_is_sized(bcx.tcx(), datum.ty)); |
7453a54e | 1428 | let dest = adt::trans_field_ptr(bcx, &repr, addr, discr, i); |
c34b1796 AL |
1429 | bcx = datum.store_to(bcx, dest); |
1430 | } | |
1431 | } | |
1432 | } | |
1433 | ||
1434 | // Finally, move scratch field values into actual field locations | |
62682a34 | 1435 | for (i, datum) in scratch_vals { |
7453a54e | 1436 | let dest = adt::trans_field_ptr(bcx, &repr, addr, discr, i); |
c34b1796 AL |
1437 | bcx = datum.store_to(bcx, dest); |
1438 | } | |
1a4d82fc | 1439 | } else { |
c34b1796 | 1440 | // No base means we can write all fields directly in place. |
92a42be0 | 1441 | let addr = adt::MaybeSizedValue::sized(addr); |
85aaf69f | 1442 | for &(i, ref e) in fields { |
7453a54e SL |
1443 | let dest = adt::trans_field_ptr(bcx, &repr, addr, discr, i); |
1444 | let e_ty = expr_ty_adjusted(bcx, &e); | |
1445 | bcx = trans_into(bcx, &e, SaveIn(dest)); | |
1a4d82fc JJ |
1446 | let scope = cleanup::CustomScope(custom_cleanup_scope); |
1447 | fcx.schedule_lifetime_end(scope, dest); | |
c1a9b12d SL |
1448 | // FIXME: nonzeroing move should generalize to fields |
1449 | fcx.schedule_drop_mem(scope, dest, e_ty, None); | |
1a4d82fc JJ |
1450 | } |
1451 | } | |
1452 | ||
7453a54e | 1453 | adt::trans_set_discr(bcx, &repr, addr, discr); |
1a4d82fc JJ |
1454 | |
1455 | fcx.pop_custom_cleanup_scope(custom_cleanup_scope); | |
1456 | ||
1457 | // If we don't care about the result drop the temporary we made | |
1458 | match dest { | |
1459 | SaveIn(_) => bcx, | |
1460 | Ignore => { | |
85aaf69f | 1461 | bcx = glue::drop_ty(bcx, addr, ty, debug_location); |
1a4d82fc JJ |
1462 | base::call_lifetime_end(bcx, addr); |
1463 | bcx | |
1464 | } | |
1465 | } | |
1466 | } | |
1467 | ||
1468 | ||
1469 | fn trans_immediate_lit<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e | 1470 | expr: &hir::Expr, |
b039eaaf | 1471 | lit: &ast::Lit) |
1a4d82fc JJ |
1472 | -> DatumBlock<'blk, 'tcx, Expr> { |
1473 | // must not be a string constant, that is a RvalueDpsExpr | |
1474 | let _icx = push_ctxt("trans_immediate_lit"); | |
1475 | let ty = expr_ty(bcx, expr); | |
1476 | let v = consts::const_lit(bcx.ccx(), expr, lit); | |
1477 | immediate_rvalue_bcx(bcx, v, ty).to_expr_datumblock() | |
1478 | } | |
1479 | ||
1480 | fn trans_unary<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e SL |
1481 | expr: &hir::Expr, |
1482 | op: hir::UnOp, | |
1483 | sub_expr: &hir::Expr) | |
1a4d82fc JJ |
1484 | -> DatumBlock<'blk, 'tcx, Expr> { |
1485 | let ccx = bcx.ccx(); | |
1486 | let mut bcx = bcx; | |
1487 | let _icx = push_ctxt("trans_unary_datum"); | |
1488 | ||
1489 | let method_call = MethodCall::expr(expr.id); | |
1490 | ||
1491 | // The only overloaded operator that is translated to a datum | |
1492 | // is an overloaded deref, since it is always yields a `&T`. | |
1493 | // Otherwise, we should be in the RvalueDpsExpr path. | |
e9174d1e | 1494 | assert!(op == hir::UnDeref || !ccx.tcx().is_method_call(expr.id)); |
1a4d82fc JJ |
1495 | |
1496 | let un_ty = expr_ty(bcx, expr); | |
1497 | ||
85aaf69f SL |
1498 | let debug_loc = expr.debug_loc(); |
1499 | ||
1a4d82fc | 1500 | match op { |
e9174d1e | 1501 | hir::UnNot => { |
1a4d82fc | 1502 | let datum = unpack_datum!(bcx, trans(bcx, sub_expr)); |
85aaf69f | 1503 | let llresult = Not(bcx, datum.to_llscalarish(bcx), debug_loc); |
1a4d82fc JJ |
1504 | immediate_rvalue_bcx(bcx, llresult, un_ty).to_expr_datumblock() |
1505 | } | |
e9174d1e | 1506 | hir::UnNeg => { |
1a4d82fc JJ |
1507 | let datum = unpack_datum!(bcx, trans(bcx, sub_expr)); |
1508 | let val = datum.to_llscalarish(bcx); | |
9346a6ac | 1509 | let (bcx, llneg) = { |
c1a9b12d | 1510 | if un_ty.is_fp() { |
9346a6ac AL |
1511 | let result = FNeg(bcx, val, debug_loc); |
1512 | (bcx, result) | |
1a4d82fc | 1513 | } else { |
c1a9b12d | 1514 | let is_signed = un_ty.is_signed(); |
9346a6ac AL |
1515 | let result = Neg(bcx, val, debug_loc); |
1516 | let bcx = if bcx.ccx().check_overflow() && is_signed { | |
1517 | let (llty, min) = base::llty_and_min_for_signed_ty(bcx, un_ty); | |
1518 | let is_min = ICmp(bcx, llvm::IntEQ, val, | |
1519 | C_integral(llty, min, true), debug_loc); | |
1520 | with_cond(bcx, is_min, |bcx| { | |
1521 | let msg = InternedString::new( | |
5bcae85e | 1522 | "attempt to negate with overflow"); |
9346a6ac AL |
1523 | controlflow::trans_fail(bcx, expr_info(expr), msg) |
1524 | }) | |
1525 | } else { | |
1526 | bcx | |
1527 | }; | |
1528 | (bcx, result) | |
1a4d82fc JJ |
1529 | } |
1530 | }; | |
1531 | immediate_rvalue_bcx(bcx, llneg, un_ty).to_expr_datumblock() | |
1532 | } | |
e9174d1e | 1533 | hir::UnDeref => { |
1a4d82fc JJ |
1534 | let datum = unpack_datum!(bcx, trans(bcx, sub_expr)); |
1535 | deref_once(bcx, expr, datum, method_call) | |
1536 | } | |
1537 | } | |
1538 | } | |
1539 | ||
1540 | fn trans_uniq_expr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e | 1541 | box_expr: &hir::Expr, |
1a4d82fc | 1542 | box_ty: Ty<'tcx>, |
e9174d1e | 1543 | contents: &hir::Expr, |
1a4d82fc JJ |
1544 | contents_ty: Ty<'tcx>) |
1545 | -> DatumBlock<'blk, 'tcx, Expr> { | |
1546 | let _icx = push_ctxt("trans_uniq_expr"); | |
1547 | let fcx = bcx.fcx; | |
1548 | assert!(type_is_sized(bcx.tcx(), contents_ty)); | |
1549 | let llty = type_of::type_of(bcx.ccx(), contents_ty); | |
1550 | let size = llsize_of(bcx.ccx(), llty); | |
1551 | let align = C_uint(bcx.ccx(), type_of::align_of(bcx.ccx(), contents_ty)); | |
1552 | let llty_ptr = llty.ptr_to(); | |
85aaf69f SL |
1553 | let Result { bcx, val } = malloc_raw_dyn(bcx, |
1554 | llty_ptr, | |
1555 | box_ty, | |
1556 | size, | |
1557 | align, | |
1558 | box_expr.debug_loc()); | |
1a4d82fc JJ |
1559 | // Unique boxes do not allocate for zero-size types. The standard library |
1560 | // may assume that `free` is never called on the pointer returned for | |
1561 | // `Box<ZeroSizeType>`. | |
1562 | let bcx = if llsize_of_alloc(bcx.ccx(), llty) == 0 { | |
1563 | trans_into(bcx, contents, SaveIn(val)) | |
1564 | } else { | |
1565 | let custom_cleanup_scope = fcx.push_custom_cleanup_scope(); | |
1566 | fcx.schedule_free_value(cleanup::CustomScope(custom_cleanup_scope), | |
1567 | val, cleanup::HeapExchange, contents_ty); | |
1568 | let bcx = trans_into(bcx, contents, SaveIn(val)); | |
1569 | fcx.pop_custom_cleanup_scope(custom_cleanup_scope); | |
1570 | bcx | |
1571 | }; | |
1572 | immediate_rvalue_bcx(bcx, val, box_ty).to_expr_datumblock() | |
1573 | } | |
1574 | ||
1575 | fn trans_addr_of<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e SL |
1576 | expr: &hir::Expr, |
1577 | subexpr: &hir::Expr) | |
1a4d82fc JJ |
1578 | -> DatumBlock<'blk, 'tcx, Expr> { |
1579 | let _icx = push_ctxt("trans_addr_of"); | |
1580 | let mut bcx = bcx; | |
1581 | let sub_datum = unpack_datum!(bcx, trans_to_lvalue(bcx, subexpr, "addr_of")); | |
b039eaaf | 1582 | let ty = expr_ty(bcx, expr); |
c34b1796 | 1583 | if !type_is_sized(bcx.tcx(), sub_datum.ty) { |
b039eaaf SL |
1584 | // Always generate an lvalue datum, because this pointer doesn't own |
1585 | // the data and cleanup is scheduled elsewhere. | |
1586 | DatumBlock::new(bcx, Datum::new(sub_datum.val, ty, LvalueExpr(sub_datum.kind))) | |
c34b1796 AL |
1587 | } else { |
1588 | // Sized value, ref to a thin pointer | |
c34b1796 | 1589 | immediate_rvalue_bcx(bcx, sub_datum.val, ty).to_expr_datumblock() |
1a4d82fc JJ |
1590 | } |
1591 | } | |
1592 | ||
e9174d1e SL |
1593 | fn trans_scalar_binop<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, |
1594 | binop_expr: &hir::Expr, | |
1595 | binop_ty: Ty<'tcx>, | |
1596 | op: hir::BinOp, | |
1597 | lhs: Datum<'tcx, Rvalue>, | |
1598 | rhs: Datum<'tcx, Rvalue>) | |
1599 | -> DatumBlock<'blk, 'tcx, Expr> | |
1600 | { | |
1601 | let _icx = push_ctxt("trans_scalar_binop"); | |
1602 | ||
e9174d1e SL |
1603 | let lhs_t = lhs.ty; |
1604 | assert!(!lhs_t.is_simd()); | |
1605 | let is_float = lhs_t.is_fp(); | |
1606 | let is_signed = lhs_t.is_signed(); | |
c34b1796 | 1607 | let info = expr_info(binop_expr); |
1a4d82fc | 1608 | |
85aaf69f SL |
1609 | let binop_debug_loc = binop_expr.debug_loc(); |
1610 | ||
1a4d82fc | 1611 | let mut bcx = bcx; |
e9174d1e SL |
1612 | let lhs = lhs.to_llscalarish(bcx); |
1613 | let rhs = rhs.to_llscalarish(bcx); | |
85aaf69f | 1614 | let val = match op.node { |
e9174d1e | 1615 | hir::BiAdd => { |
85aaf69f SL |
1616 | if is_float { |
1617 | FAdd(bcx, lhs, rhs, binop_debug_loc) | |
c34b1796 AL |
1618 | } else { |
1619 | let (newbcx, res) = with_overflow_check( | |
1620 | bcx, OverflowOp::Add, info, lhs_t, lhs, rhs, binop_debug_loc); | |
1621 | bcx = newbcx; | |
1622 | res | |
85aaf69f | 1623 | } |
1a4d82fc | 1624 | } |
e9174d1e | 1625 | hir::BiSub => { |
85aaf69f SL |
1626 | if is_float { |
1627 | FSub(bcx, lhs, rhs, binop_debug_loc) | |
c34b1796 AL |
1628 | } else { |
1629 | let (newbcx, res) = with_overflow_check( | |
1630 | bcx, OverflowOp::Sub, info, lhs_t, lhs, rhs, binop_debug_loc); | |
1631 | bcx = newbcx; | |
1632 | res | |
85aaf69f | 1633 | } |
1a4d82fc | 1634 | } |
e9174d1e | 1635 | hir::BiMul => { |
85aaf69f SL |
1636 | if is_float { |
1637 | FMul(bcx, lhs, rhs, binop_debug_loc) | |
c34b1796 AL |
1638 | } else { |
1639 | let (newbcx, res) = with_overflow_check( | |
1640 | bcx, OverflowOp::Mul, info, lhs_t, lhs, rhs, binop_debug_loc); | |
1641 | bcx = newbcx; | |
1642 | res | |
85aaf69f | 1643 | } |
1a4d82fc | 1644 | } |
e9174d1e | 1645 | hir::BiDiv => { |
1a4d82fc | 1646 | if is_float { |
85aaf69f | 1647 | FDiv(bcx, lhs, rhs, binop_debug_loc) |
1a4d82fc JJ |
1648 | } else { |
1649 | // Only zero-check integers; fp /0 is NaN | |
85aaf69f SL |
1650 | bcx = base::fail_if_zero_or_overflows(bcx, |
1651 | expr_info(binop_expr), | |
1652 | op, | |
1653 | lhs, | |
1654 | rhs, | |
e9174d1e | 1655 | lhs_t); |
1a4d82fc | 1656 | if is_signed { |
85aaf69f | 1657 | SDiv(bcx, lhs, rhs, binop_debug_loc) |
1a4d82fc | 1658 | } else { |
85aaf69f | 1659 | UDiv(bcx, lhs, rhs, binop_debug_loc) |
1a4d82fc JJ |
1660 | } |
1661 | } | |
1662 | } | |
e9174d1e | 1663 | hir::BiRem => { |
1a4d82fc | 1664 | if is_float { |
a7813a04 | 1665 | FRem(bcx, lhs, rhs, binop_debug_loc) |
1a4d82fc JJ |
1666 | } else { |
1667 | // Only zero-check integers; fp %0 is NaN | |
85aaf69f SL |
1668 | bcx = base::fail_if_zero_or_overflows(bcx, |
1669 | expr_info(binop_expr), | |
e9174d1e | 1670 | op, lhs, rhs, lhs_t); |
1a4d82fc | 1671 | if is_signed { |
85aaf69f | 1672 | SRem(bcx, lhs, rhs, binop_debug_loc) |
1a4d82fc | 1673 | } else { |
85aaf69f | 1674 | URem(bcx, lhs, rhs, binop_debug_loc) |
1a4d82fc JJ |
1675 | } |
1676 | } | |
1677 | } | |
e9174d1e SL |
1678 | hir::BiBitOr => Or(bcx, lhs, rhs, binop_debug_loc), |
1679 | hir::BiBitAnd => And(bcx, lhs, rhs, binop_debug_loc), | |
1680 | hir::BiBitXor => Xor(bcx, lhs, rhs, binop_debug_loc), | |
1681 | hir::BiShl => { | |
c34b1796 AL |
1682 | let (newbcx, res) = with_overflow_check( |
1683 | bcx, OverflowOp::Shl, info, lhs_t, lhs, rhs, binop_debug_loc); | |
1684 | bcx = newbcx; | |
1685 | res | |
1686 | } | |
e9174d1e | 1687 | hir::BiShr => { |
c34b1796 AL |
1688 | let (newbcx, res) = with_overflow_check( |
1689 | bcx, OverflowOp::Shr, info, lhs_t, lhs, rhs, binop_debug_loc); | |
1690 | bcx = newbcx; | |
1691 | res | |
1a4d82fc | 1692 | } |
e9174d1e SL |
1693 | hir::BiEq | hir::BiNe | hir::BiLt | hir::BiGe | hir::BiLe | hir::BiGt => { |
1694 | base::compare_scalar_types(bcx, lhs, rhs, lhs_t, op.node, binop_debug_loc) | |
1a4d82fc JJ |
1695 | } |
1696 | _ => { | |
54a0048b | 1697 | span_bug!(binop_expr.span, "unexpected binop"); |
1a4d82fc JJ |
1698 | } |
1699 | }; | |
1700 | ||
1701 | immediate_rvalue_bcx(bcx, val, binop_ty).to_expr_datumblock() | |
1702 | } | |
1703 | ||
1704 | // refinement types would obviate the need for this | |
5bcae85e | 1705 | #[derive(Clone, Copy)] |
1a4d82fc JJ |
1706 | enum lazy_binop_ty { |
1707 | lazy_and, | |
1708 | lazy_or, | |
1709 | } | |
1710 | ||
5bcae85e | 1711 | |
1a4d82fc | 1712 | fn trans_lazy_binop<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, |
e9174d1e | 1713 | binop_expr: &hir::Expr, |
1a4d82fc | 1714 | op: lazy_binop_ty, |
e9174d1e SL |
1715 | a: &hir::Expr, |
1716 | b: &hir::Expr) | |
1a4d82fc JJ |
1717 | -> DatumBlock<'blk, 'tcx, Expr> { |
1718 | let _icx = push_ctxt("trans_lazy_binop"); | |
1719 | let binop_ty = expr_ty(bcx, binop_expr); | |
1720 | let fcx = bcx.fcx; | |
1721 | ||
1722 | let DatumBlock {bcx: past_lhs, datum: lhs} = trans(bcx, a); | |
1723 | let lhs = lhs.to_llscalarish(past_lhs); | |
1724 | ||
1725 | if past_lhs.unreachable.get() { | |
1726 | return immediate_rvalue_bcx(past_lhs, lhs, binop_ty).to_expr_datumblock(); | |
1727 | } | |
1728 | ||
5bcae85e SL |
1729 | // If the rhs can never be reached, don't generate code for it. |
1730 | if let Some(cond_val) = const_to_opt_uint(lhs) { | |
1731 | match (cond_val, op) { | |
1732 | (0, lazy_and) | | |
1733 | (1, lazy_or) => { | |
1734 | return immediate_rvalue_bcx(past_lhs, lhs, binop_ty).to_expr_datumblock(); | |
1735 | } | |
1736 | _ => { /* continue */ } | |
1737 | } | |
1738 | } | |
1739 | ||
1a4d82fc JJ |
1740 | let join = fcx.new_id_block("join", binop_expr.id); |
1741 | let before_rhs = fcx.new_id_block("before_rhs", b.id); | |
1742 | ||
1743 | match op { | |
85aaf69f SL |
1744 | lazy_and => CondBr(past_lhs, lhs, before_rhs.llbb, join.llbb, DebugLoc::None), |
1745 | lazy_or => CondBr(past_lhs, lhs, join.llbb, before_rhs.llbb, DebugLoc::None) | |
1a4d82fc JJ |
1746 | } |
1747 | ||
1748 | let DatumBlock {bcx: past_rhs, datum: rhs} = trans(before_rhs, b); | |
1749 | let rhs = rhs.to_llscalarish(past_rhs); | |
1750 | ||
1751 | if past_rhs.unreachable.get() { | |
1752 | return immediate_rvalue_bcx(join, lhs, binop_ty).to_expr_datumblock(); | |
1753 | } | |
1754 | ||
85aaf69f | 1755 | Br(past_rhs, join.llbb, DebugLoc::None); |
1a4d82fc JJ |
1756 | let phi = Phi(join, Type::i1(bcx.ccx()), &[lhs, rhs], |
1757 | &[past_lhs.llbb, past_rhs.llbb]); | |
1758 | ||
1759 | return immediate_rvalue_bcx(join, phi, binop_ty).to_expr_datumblock(); | |
1760 | } | |
1761 | ||
1762 | fn trans_binary<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e SL |
1763 | expr: &hir::Expr, |
1764 | op: hir::BinOp, | |
1765 | lhs: &hir::Expr, | |
1766 | rhs: &hir::Expr) | |
1a4d82fc JJ |
1767 | -> DatumBlock<'blk, 'tcx, Expr> { |
1768 | let _icx = push_ctxt("trans_binary"); | |
1769 | let ccx = bcx.ccx(); | |
1770 | ||
1771 | // if overloaded, would be RvalueDpsExpr | |
c1a9b12d | 1772 | assert!(!ccx.tcx().is_method_call(expr.id)); |
1a4d82fc | 1773 | |
85aaf69f | 1774 | match op.node { |
e9174d1e | 1775 | hir::BiAnd => { |
1a4d82fc JJ |
1776 | trans_lazy_binop(bcx, expr, lazy_and, lhs, rhs) |
1777 | } | |
e9174d1e | 1778 | hir::BiOr => { |
1a4d82fc JJ |
1779 | trans_lazy_binop(bcx, expr, lazy_or, lhs, rhs) |
1780 | } | |
1781 | _ => { | |
1782 | let mut bcx = bcx; | |
1a4d82fc JJ |
1783 | let binop_ty = expr_ty(bcx, expr); |
1784 | ||
e9174d1e SL |
1785 | let lhs = unpack_datum!(bcx, trans(bcx, lhs)); |
1786 | let lhs = unpack_datum!(bcx, lhs.to_rvalue_datum(bcx, "binop_lhs")); | |
54a0048b | 1787 | debug!("trans_binary (expr {}): lhs={:?}", expr.id, lhs); |
e9174d1e SL |
1788 | let rhs = unpack_datum!(bcx, trans(bcx, rhs)); |
1789 | let rhs = unpack_datum!(bcx, rhs.to_rvalue_datum(bcx, "binop_rhs")); | |
54a0048b | 1790 | debug!("trans_binary (expr {}): rhs={:?}", expr.id, rhs); |
e9174d1e SL |
1791 | |
1792 | if type_is_fat_ptr(ccx.tcx(), lhs.ty) { | |
1793 | assert!(type_is_fat_ptr(ccx.tcx(), rhs.ty), | |
1794 | "built-in binary operators on fat pointers are homogeneous"); | |
92a42be0 SL |
1795 | assert_eq!(binop_ty, bcx.tcx().types.bool); |
1796 | let val = base::compare_scalar_types( | |
1797 | bcx, | |
1798 | lhs.val, | |
1799 | rhs.val, | |
1800 | lhs.ty, | |
1801 | op.node, | |
1802 | expr.debug_loc()); | |
1803 | immediate_rvalue_bcx(bcx, val, binop_ty).to_expr_datumblock() | |
e9174d1e SL |
1804 | } else { |
1805 | assert!(!type_is_fat_ptr(ccx.tcx(), rhs.ty), | |
1806 | "built-in binary operators on fat pointers are homogeneous"); | |
1807 | trans_scalar_binop(bcx, expr, binop_ty, op, lhs, rhs) | |
1808 | } | |
1a4d82fc JJ |
1809 | } |
1810 | } | |
1811 | } | |
1812 | ||
a7813a04 XL |
1813 | pub fn cast_is_noop<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
1814 | expr: &hir::Expr, | |
1815 | t_in: Ty<'tcx>, | |
1816 | t_out: Ty<'tcx>) | |
1817 | -> bool { | |
62682a34 SL |
1818 | if let Some(&CastKind::CoercionCast) = tcx.cast_kinds.borrow().get(&expr.id) { |
1819 | return true; | |
1a4d82fc | 1820 | } |
1a4d82fc | 1821 | |
e9174d1e SL |
1822 | match (t_in.builtin_deref(true, ty::NoPreference), |
1823 | t_out.builtin_deref(true, ty::NoPreference)) { | |
c1a9b12d | 1824 | (Some(ty::TypeAndMut{ ty: t_in, .. }), Some(ty::TypeAndMut{ ty: t_out, .. })) => { |
1a4d82fc JJ |
1825 | t_in == t_out |
1826 | } | |
62682a34 SL |
1827 | _ => { |
1828 | // This condition isn't redundant with the check for CoercionCast: | |
1829 | // different types can be substituted into the same type, and | |
1830 | // == equality can be overconservative if there are regions. | |
1831 | t_in == t_out | |
1832 | } | |
1a4d82fc JJ |
1833 | } |
1834 | } | |
1835 | ||
1836 | fn trans_imm_cast<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e | 1837 | expr: &hir::Expr, |
1a4d82fc | 1838 | id: ast::NodeId) |
62682a34 SL |
1839 | -> DatumBlock<'blk, 'tcx, Expr> |
1840 | { | |
54a0048b SL |
1841 | use rustc::ty::cast::CastTy::*; |
1842 | use rustc::ty::cast::IntTy::*; | |
62682a34 SL |
1843 | |
1844 | fn int_cast(bcx: Block, | |
1845 | lldsttype: Type, | |
1846 | llsrctype: Type, | |
1847 | llsrc: ValueRef, | |
1848 | signed: bool) | |
1849 | -> ValueRef | |
1850 | { | |
1851 | let _icx = push_ctxt("int_cast"); | |
1852 | let srcsz = llsrctype.int_width(); | |
1853 | let dstsz = lldsttype.int_width(); | |
1854 | return if dstsz == srcsz { | |
1855 | BitCast(bcx, llsrc, lldsttype) | |
1856 | } else if srcsz > dstsz { | |
1857 | TruncOrBitCast(bcx, llsrc, lldsttype) | |
1858 | } else if signed { | |
1859 | SExtOrBitCast(bcx, llsrc, lldsttype) | |
1860 | } else { | |
1861 | ZExtOrBitCast(bcx, llsrc, lldsttype) | |
1862 | } | |
1863 | } | |
1864 | ||
1865 | fn float_cast(bcx: Block, | |
1866 | lldsttype: Type, | |
1867 | llsrctype: Type, | |
1868 | llsrc: ValueRef) | |
1869 | -> ValueRef | |
1870 | { | |
1871 | let _icx = push_ctxt("float_cast"); | |
1872 | let srcsz = llsrctype.float_width(); | |
1873 | let dstsz = lldsttype.float_width(); | |
1874 | return if dstsz > srcsz { | |
1875 | FPExt(bcx, llsrc, lldsttype) | |
1876 | } else if srcsz > dstsz { | |
1877 | FPTrunc(bcx, llsrc, lldsttype) | |
1878 | } else { llsrc }; | |
1879 | } | |
1880 | ||
1a4d82fc JJ |
1881 | let _icx = push_ctxt("trans_cast"); |
1882 | let mut bcx = bcx; | |
1883 | let ccx = bcx.ccx(); | |
1884 | ||
c34b1796 | 1885 | let t_in = expr_ty_adjusted(bcx, expr); |
1a4d82fc | 1886 | let t_out = node_id_type(bcx, id); |
1a4d82fc | 1887 | |
62682a34 | 1888 | debug!("trans_cast({:?} as {:?})", t_in, t_out); |
54a0048b SL |
1889 | let mut ll_t_in = type_of::immediate_type_of(ccx, t_in); |
1890 | let ll_t_out = type_of::immediate_type_of(ccx, t_out); | |
1a4d82fc JJ |
1891 | // Convert the value to be cast into a ValueRef, either by-ref or |
1892 | // by-value as appropriate given its type: | |
1893 | let mut datum = unpack_datum!(bcx, trans(bcx, expr)); | |
1894 | ||
c34b1796 | 1895 | let datum_ty = monomorphize_type(bcx, datum.ty); |
62682a34 SL |
1896 | |
1897 | if cast_is_noop(bcx.tcx(), expr, datum_ty, t_out) { | |
1a4d82fc JJ |
1898 | datum.ty = t_out; |
1899 | return DatumBlock::new(bcx, datum); | |
1900 | } | |
1901 | ||
62682a34 SL |
1902 | if type_is_fat_ptr(bcx.tcx(), t_in) { |
1903 | assert!(datum.kind.is_by_ref()); | |
1904 | if type_is_fat_ptr(bcx.tcx(), t_out) { | |
1905 | return DatumBlock::new(bcx, Datum::new( | |
1906 | PointerCast(bcx, datum.val, ll_t_out.ptr_to()), | |
1907 | t_out, | |
1908 | Rvalue::new(ByRef) | |
1909 | )).to_expr_datumblock(); | |
1910 | } else { | |
1911 | // Return the address | |
1912 | return immediate_rvalue_bcx(bcx, | |
1913 | PointerCast(bcx, | |
1914 | Load(bcx, get_dataptr(bcx, datum.val)), | |
1915 | ll_t_out), | |
1916 | t_out).to_expr_datumblock(); | |
d9579d0f | 1917 | } |
62682a34 SL |
1918 | } |
1919 | ||
e9174d1e SL |
1920 | let r_t_in = CastTy::from_ty(t_in).expect("bad input type for cast"); |
1921 | let r_t_out = CastTy::from_ty(t_out).expect("bad output type for cast"); | |
62682a34 SL |
1922 | |
1923 | let (llexpr, signed) = if let Int(CEnum) = r_t_in { | |
1924 | let repr = adt::represent_type(ccx, t_in); | |
1925 | let datum = unpack_datum!( | |
1926 | bcx, datum.to_lvalue_datum(bcx, "trans_imm_cast", expr.id)); | |
1927 | let llexpr_ptr = datum.to_llref(); | |
7453a54e SL |
1928 | let discr = adt::trans_get_discr(bcx, &repr, llexpr_ptr, |
1929 | Some(Type::i64(ccx)), true); | |
62682a34 | 1930 | ll_t_in = val_ty(discr); |
7453a54e | 1931 | (discr, adt::is_discr_signed(&repr)) |
62682a34 | 1932 | } else { |
c1a9b12d | 1933 | (datum.to_llscalarish(bcx), t_in.is_signed()) |
62682a34 SL |
1934 | }; |
1935 | ||
1936 | let newval = match (r_t_in, r_t_out) { | |
1937 | (Ptr(_), Ptr(_)) | (FnPtr, Ptr(_)) | (RPtr(_), Ptr(_)) => { | |
1938 | PointerCast(bcx, llexpr, ll_t_out) | |
1a4d82fc | 1939 | } |
62682a34 SL |
1940 | (Ptr(_), Int(_)) | (FnPtr, Int(_)) => PtrToInt(bcx, llexpr, ll_t_out), |
1941 | (Int(_), Ptr(_)) => IntToPtr(bcx, llexpr, ll_t_out), | |
1942 | ||
1943 | (Int(_), Int(_)) => int_cast(bcx, ll_t_out, ll_t_in, llexpr, signed), | |
1944 | (Float, Float) => float_cast(bcx, ll_t_out, ll_t_in, llexpr), | |
1945 | (Int(_), Float) if signed => SIToFP(bcx, llexpr, ll_t_out), | |
1946 | (Int(_), Float) => UIToFP(bcx, llexpr, ll_t_out), | |
1947 | (Float, Int(I)) => FPToSI(bcx, llexpr, ll_t_out), | |
1948 | (Float, Int(_)) => FPToUI(bcx, llexpr, ll_t_out), | |
1949 | ||
54a0048b SL |
1950 | _ => span_bug!(expr.span, |
1951 | "translating unsupported cast: \ | |
1952 | {:?} -> {:?}", | |
1953 | t_in, | |
1954 | t_out) | |
1a4d82fc JJ |
1955 | }; |
1956 | return immediate_rvalue_bcx(bcx, newval, t_out).to_expr_datumblock(); | |
1957 | } | |
1958 | ||
1959 | fn trans_assign_op<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e SL |
1960 | expr: &hir::Expr, |
1961 | op: hir::BinOp, | |
1962 | dst: &hir::Expr, | |
1963 | src: &hir::Expr) | |
1a4d82fc JJ |
1964 | -> Block<'blk, 'tcx> { |
1965 | let _icx = push_ctxt("trans_assign_op"); | |
1966 | let mut bcx = bcx; | |
1967 | ||
62682a34 | 1968 | debug!("trans_assign_op(expr={:?})", expr); |
1a4d82fc JJ |
1969 | |
1970 | // User-defined operator methods cannot be used with `+=` etc right now | |
c1a9b12d | 1971 | assert!(!bcx.tcx().is_method_call(expr.id)); |
1a4d82fc JJ |
1972 | |
1973 | // Evaluate LHS (destination), which should be an lvalue | |
e9174d1e SL |
1974 | let dst = unpack_datum!(bcx, trans_to_lvalue(bcx, dst, "assign_op")); |
1975 | assert!(!bcx.fcx.type_needs_drop(dst.ty)); | |
1976 | let lhs = load_ty(bcx, dst.val, dst.ty); | |
1977 | let lhs = immediate_rvalue(lhs, dst.ty); | |
1a4d82fc | 1978 | |
e9174d1e | 1979 | // Evaluate RHS - FIXME(#28160) this sucks |
7453a54e | 1980 | let rhs = unpack_datum!(bcx, trans(bcx, &src)); |
e9174d1e | 1981 | let rhs = unpack_datum!(bcx, rhs.to_rvalue_datum(bcx, "assign_op_rhs")); |
1a4d82fc JJ |
1982 | |
1983 | // Perform computation and store the result | |
1984 | let result_datum = unpack_datum!( | |
e9174d1e SL |
1985 | bcx, trans_scalar_binop(bcx, expr, dst.ty, op, lhs, rhs)); |
1986 | return result_datum.store_to(bcx, dst.val); | |
1a4d82fc JJ |
1987 | } |
1988 | ||
1989 | fn auto_ref<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
1990 | datum: Datum<'tcx, Expr>, | |
e9174d1e | 1991 | expr: &hir::Expr) |
1a4d82fc JJ |
1992 | -> DatumBlock<'blk, 'tcx, Expr> { |
1993 | let mut bcx = bcx; | |
1994 | ||
1995 | // Ensure cleanup of `datum` if not already scheduled and obtain | |
1996 | // a "by ref" pointer. | |
1997 | let lv_datum = unpack_datum!(bcx, datum.to_lvalue_datum(bcx, "autoref", expr.id)); | |
1998 | ||
1999 | // Compute final type. Note that we are loose with the region and | |
2000 | // mutability, since those things don't matter in trans. | |
2001 | let referent_ty = lv_datum.ty; | |
3157f602 | 2002 | let ptr_ty = bcx.tcx().mk_imm_ref(bcx.tcx().mk_region(ty::ReErased), referent_ty); |
1a4d82fc | 2003 | |
9cc50fc6 SL |
2004 | // Construct the resulting datum. The right datum to return here would be an Lvalue datum, |
2005 | // because there is cleanup scheduled and the datum doesn't own the data, but for thin pointers | |
2006 | // we microoptimize it to be an Rvalue datum to avoid the extra alloca and level of | |
2007 | // indirection and for thin pointers, this has no ill effects. | |
2008 | let kind = if type_is_sized(bcx.tcx(), referent_ty) { | |
2009 | RvalueExpr(Rvalue::new(ByValue)) | |
2010 | } else { | |
2011 | LvalueExpr(lv_datum.kind) | |
2012 | }; | |
2013 | ||
1a4d82fc JJ |
2014 | // Get the pointer. |
2015 | let llref = lv_datum.to_llref(); | |
9cc50fc6 | 2016 | DatumBlock::new(bcx, Datum::new(llref, ptr_ty, kind)) |
1a4d82fc JJ |
2017 | } |
2018 | ||
2019 | fn deref_multiple<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e | 2020 | expr: &hir::Expr, |
1a4d82fc | 2021 | datum: Datum<'tcx, Expr>, |
c34b1796 | 2022 | times: usize) |
1a4d82fc JJ |
2023 | -> DatumBlock<'blk, 'tcx, Expr> { |
2024 | let mut bcx = bcx; | |
2025 | let mut datum = datum; | |
85aaf69f | 2026 | for i in 0..times { |
9346a6ac | 2027 | let method_call = MethodCall::autoderef(expr.id, i as u32); |
1a4d82fc JJ |
2028 | datum = unpack_datum!(bcx, deref_once(bcx, expr, datum, method_call)); |
2029 | } | |
2030 | DatumBlock { bcx: bcx, datum: datum } | |
2031 | } | |
2032 | ||
2033 | fn deref_once<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
e9174d1e | 2034 | expr: &hir::Expr, |
1a4d82fc JJ |
2035 | datum: Datum<'tcx, Expr>, |
2036 | method_call: MethodCall) | |
2037 | -> DatumBlock<'blk, 'tcx, Expr> { | |
2038 | let ccx = bcx.ccx(); | |
2039 | ||
54a0048b SL |
2040 | debug!("deref_once(expr={:?}, datum={:?}, method_call={:?})", |
2041 | expr, datum, method_call); | |
1a4d82fc JJ |
2042 | |
2043 | let mut bcx = bcx; | |
2044 | ||
2045 | // Check for overloaded deref. | |
54a0048b SL |
2046 | let method = ccx.tcx().tables.borrow().method_map.get(&method_call).cloned(); |
2047 | let datum = match method { | |
2048 | Some(method) => { | |
2049 | let method_ty = monomorphize_type(bcx, method.ty); | |
2050 | ||
2051 | // Overloaded. Invoke the deref() method, which basically | |
1a4d82fc JJ |
2052 | // converts from the `Smaht<T>` pointer that we have into |
2053 | // a `&T` pointer. We can then proceed down the normal | |
2054 | // path (below) to dereference that `&T`. | |
9346a6ac AL |
2055 | let datum = if method_call.autoderef == 0 { |
2056 | datum | |
2057 | } else { | |
1a4d82fc | 2058 | // Always perform an AutoPtr when applying an overloaded auto-deref |
9346a6ac | 2059 | unpack_datum!(bcx, auto_ref(bcx, datum, expr)) |
1a4d82fc JJ |
2060 | }; |
2061 | ||
2062 | let ref_ty = // invoked methods have their LB regions instantiated | |
5bcae85e | 2063 | ccx.tcx().no_late_bound_regions(&method_ty.fn_ret()).unwrap(); |
1a4d82fc JJ |
2064 | let scratch = rvalue_scratch_datum(bcx, ref_ty, "overloaded_deref"); |
2065 | ||
54a0048b SL |
2066 | bcx = Callee::method(bcx, method) |
2067 | .call(bcx, expr.debug_loc(), | |
2068 | ArgOverloadedOp(datum, None), | |
2069 | Some(SaveIn(scratch.val))).bcx; | |
1a4d82fc JJ |
2070 | scratch.to_expr_datum() |
2071 | } | |
2072 | None => { | |
2073 | // Not overloaded. We already have a pointer we know how to deref. | |
2074 | datum | |
2075 | } | |
2076 | }; | |
2077 | ||
2078 | let r = match datum.ty.sty { | |
62682a34 SL |
2079 | ty::TyBox(content_ty) => { |
2080 | // Make sure we have an lvalue datum here to get the | |
2081 | // proper cleanups scheduled | |
2082 | let datum = unpack_datum!( | |
2083 | bcx, datum.to_lvalue_datum(bcx, "deref", expr.id)); | |
2084 | ||
1a4d82fc | 2085 | if type_is_sized(bcx.tcx(), content_ty) { |
62682a34 | 2086 | let ptr = load_ty(bcx, datum.val, datum.ty); |
c1a9b12d | 2087 | DatumBlock::new(bcx, Datum::new(ptr, content_ty, LvalueExpr(datum.kind))) |
1a4d82fc | 2088 | } else { |
c34b1796 AL |
2089 | // A fat pointer and a DST lvalue have the same representation |
2090 | // just different types. Since there is no temporary for `*e` | |
2091 | // here (because it is unsized), we cannot emulate the sized | |
2092 | // object code path for running drop glue and free. Instead, | |
2093 | // we schedule cleanup for `e`, turning it into an lvalue. | |
1a4d82fc | 2094 | |
c1a9b12d SL |
2095 | let lval = Lvalue::new("expr::deref_once ty_uniq"); |
2096 | let datum = Datum::new(datum.val, content_ty, LvalueExpr(lval)); | |
1a4d82fc JJ |
2097 | DatumBlock::new(bcx, datum) |
2098 | } | |
2099 | } | |
2100 | ||
c1a9b12d SL |
2101 | ty::TyRawPtr(ty::TypeAndMut { ty: content_ty, .. }) | |
2102 | ty::TyRef(_, ty::TypeAndMut { ty: content_ty, .. }) => { | |
2103 | let lval = Lvalue::new("expr::deref_once ptr"); | |
1a4d82fc JJ |
2104 | if type_is_sized(bcx.tcx(), content_ty) { |
2105 | let ptr = datum.to_llscalarish(bcx); | |
2106 | ||
2107 | // Always generate an lvalue datum, even if datum.mode is | |
2108 | // an rvalue. This is because datum.mode is only an | |
2109 | // rvalue for non-owning pointers like &T or *T, in which | |
2110 | // case cleanup *is* scheduled elsewhere, by the true | |
2111 | // owner (or, in the case of *T, by the user). | |
c1a9b12d | 2112 | DatumBlock::new(bcx, Datum::new(ptr, content_ty, LvalueExpr(lval))) |
1a4d82fc | 2113 | } else { |
c34b1796 | 2114 | // A fat pointer and a DST lvalue have the same representation |
1a4d82fc | 2115 | // just different types. |
c1a9b12d | 2116 | DatumBlock::new(bcx, Datum::new(datum.val, content_ty, LvalueExpr(lval))) |
1a4d82fc JJ |
2117 | } |
2118 | } | |
2119 | ||
2120 | _ => { | |
54a0048b | 2121 | span_bug!( |
1a4d82fc | 2122 | expr.span, |
54a0048b SL |
2123 | "deref invoked on expr of invalid type {:?}", |
2124 | datum.ty); | |
1a4d82fc JJ |
2125 | } |
2126 | }; | |
2127 | ||
54a0048b SL |
2128 | debug!("deref_once(expr={}, method_call={:?}, result={:?})", |
2129 | expr.id, method_call, r.datum); | |
1a4d82fc JJ |
2130 | |
2131 | return r; | |
1a4d82fc | 2132 | } |
c34b1796 AL |
2133 | |
2134 | #[derive(Debug)] | |
2135 | enum OverflowOp { | |
2136 | Add, | |
2137 | Sub, | |
2138 | Mul, | |
2139 | Shl, | |
2140 | Shr, | |
2141 | } | |
2142 | ||
2143 | impl OverflowOp { | |
2144 | fn codegen_strategy(&self) -> OverflowCodegen { | |
2145 | use self::OverflowCodegen::{ViaIntrinsic, ViaInputCheck}; | |
2146 | match *self { | |
2147 | OverflowOp::Add => ViaIntrinsic(OverflowOpViaIntrinsic::Add), | |
2148 | OverflowOp::Sub => ViaIntrinsic(OverflowOpViaIntrinsic::Sub), | |
2149 | OverflowOp::Mul => ViaIntrinsic(OverflowOpViaIntrinsic::Mul), | |
2150 | ||
2151 | OverflowOp::Shl => ViaInputCheck(OverflowOpViaInputCheck::Shl), | |
2152 | OverflowOp::Shr => ViaInputCheck(OverflowOpViaInputCheck::Shr), | |
2153 | } | |
2154 | } | |
2155 | } | |
2156 | ||
2157 | enum OverflowCodegen { | |
2158 | ViaIntrinsic(OverflowOpViaIntrinsic), | |
2159 | ViaInputCheck(OverflowOpViaInputCheck), | |
2160 | } | |
2161 | ||
2162 | enum OverflowOpViaInputCheck { Shl, Shr, } | |
2163 | ||
2164 | #[derive(Debug)] | |
2165 | enum OverflowOpViaIntrinsic { Add, Sub, Mul, } | |
2166 | ||
2167 | impl OverflowOpViaIntrinsic { | |
2168 | fn to_intrinsic<'blk, 'tcx>(&self, bcx: Block<'blk, 'tcx>, lhs_ty: Ty) -> ValueRef { | |
2169 | let name = self.to_intrinsic_name(bcx.tcx(), lhs_ty); | |
2170 | bcx.ccx().get_intrinsic(&name) | |
2171 | } | |
a7813a04 | 2172 | fn to_intrinsic_name(&self, tcx: TyCtxt, ty: Ty) -> &'static str { |
b039eaaf SL |
2173 | use syntax::ast::IntTy::*; |
2174 | use syntax::ast::UintTy::*; | |
54a0048b | 2175 | use rustc::ty::{TyInt, TyUint}; |
c34b1796 AL |
2176 | |
2177 | let new_sty = match ty.sty { | |
7453a54e | 2178 | TyInt(Is) => match &tcx.sess.target.target.target_pointer_width[..] { |
3157f602 | 2179 | "16" => TyInt(I16), |
7453a54e SL |
2180 | "32" => TyInt(I32), |
2181 | "64" => TyInt(I64), | |
54a0048b | 2182 | _ => bug!("unsupported target word size") |
c34b1796 | 2183 | }, |
7453a54e | 2184 | TyUint(Us) => match &tcx.sess.target.target.target_pointer_width[..] { |
3157f602 | 2185 | "16" => TyUint(U16), |
7453a54e SL |
2186 | "32" => TyUint(U32), |
2187 | "64" => TyUint(U64), | |
54a0048b | 2188 | _ => bug!("unsupported target word size") |
c34b1796 | 2189 | }, |
62682a34 | 2190 | ref t @ TyUint(_) | ref t @ TyInt(_) => t.clone(), |
54a0048b SL |
2191 | _ => bug!("tried to get overflow intrinsic for {:?} applied to non-int type", |
2192 | *self) | |
c34b1796 AL |
2193 | }; |
2194 | ||
2195 | match *self { | |
2196 | OverflowOpViaIntrinsic::Add => match new_sty { | |
7453a54e SL |
2197 | TyInt(I8) => "llvm.sadd.with.overflow.i8", |
2198 | TyInt(I16) => "llvm.sadd.with.overflow.i16", | |
2199 | TyInt(I32) => "llvm.sadd.with.overflow.i32", | |
2200 | TyInt(I64) => "llvm.sadd.with.overflow.i64", | |
c34b1796 | 2201 | |
7453a54e SL |
2202 | TyUint(U8) => "llvm.uadd.with.overflow.i8", |
2203 | TyUint(U16) => "llvm.uadd.with.overflow.i16", | |
2204 | TyUint(U32) => "llvm.uadd.with.overflow.i32", | |
2205 | TyUint(U64) => "llvm.uadd.with.overflow.i64", | |
c34b1796 | 2206 | |
54a0048b | 2207 | _ => bug!(), |
c34b1796 AL |
2208 | }, |
2209 | OverflowOpViaIntrinsic::Sub => match new_sty { | |
7453a54e SL |
2210 | TyInt(I8) => "llvm.ssub.with.overflow.i8", |
2211 | TyInt(I16) => "llvm.ssub.with.overflow.i16", | |
2212 | TyInt(I32) => "llvm.ssub.with.overflow.i32", | |
2213 | TyInt(I64) => "llvm.ssub.with.overflow.i64", | |
c34b1796 | 2214 | |
7453a54e SL |
2215 | TyUint(U8) => "llvm.usub.with.overflow.i8", |
2216 | TyUint(U16) => "llvm.usub.with.overflow.i16", | |
2217 | TyUint(U32) => "llvm.usub.with.overflow.i32", | |
2218 | TyUint(U64) => "llvm.usub.with.overflow.i64", | |
c34b1796 | 2219 | |
54a0048b | 2220 | _ => bug!(), |
c34b1796 AL |
2221 | }, |
2222 | OverflowOpViaIntrinsic::Mul => match new_sty { | |
7453a54e SL |
2223 | TyInt(I8) => "llvm.smul.with.overflow.i8", |
2224 | TyInt(I16) => "llvm.smul.with.overflow.i16", | |
2225 | TyInt(I32) => "llvm.smul.with.overflow.i32", | |
2226 | TyInt(I64) => "llvm.smul.with.overflow.i64", | |
c34b1796 | 2227 | |
7453a54e SL |
2228 | TyUint(U8) => "llvm.umul.with.overflow.i8", |
2229 | TyUint(U16) => "llvm.umul.with.overflow.i16", | |
2230 | TyUint(U32) => "llvm.umul.with.overflow.i32", | |
2231 | TyUint(U64) => "llvm.umul.with.overflow.i64", | |
c34b1796 | 2232 | |
54a0048b | 2233 | _ => bug!(), |
c34b1796 AL |
2234 | }, |
2235 | } | |
2236 | } | |
2237 | ||
2238 | fn build_intrinsic_call<'blk, 'tcx>(&self, bcx: Block<'blk, 'tcx>, | |
2239 | info: NodeIdAndSpan, | |
2240 | lhs_t: Ty<'tcx>, lhs: ValueRef, | |
2241 | rhs: ValueRef, | |
2242 | binop_debug_loc: DebugLoc) | |
2243 | -> (Block<'blk, 'tcx>, ValueRef) { | |
3157f602 XL |
2244 | use rustc_const_math::{ConstMathErr, Op}; |
2245 | ||
c34b1796 AL |
2246 | let llfn = self.to_intrinsic(bcx, lhs_t); |
2247 | ||
54a0048b | 2248 | let val = Call(bcx, llfn, &[lhs, rhs], binop_debug_loc); |
c34b1796 AL |
2249 | let result = ExtractValue(bcx, val, 0); // iN operation result |
2250 | let overflow = ExtractValue(bcx, val, 1); // i1 "did it overflow?" | |
2251 | ||
2252 | let cond = ICmp(bcx, llvm::IntEQ, overflow, C_integral(Type::i1(bcx.ccx()), 1, false), | |
2253 | binop_debug_loc); | |
2254 | ||
2255 | let expect = bcx.ccx().get_intrinsic(&"llvm.expect.i1"); | |
3157f602 XL |
2256 | let expected = Call(bcx, expect, &[cond, C_bool(bcx.ccx(), false)], |
2257 | binop_debug_loc); | |
2258 | ||
2259 | let op = match *self { | |
2260 | OverflowOpViaIntrinsic::Add => Op::Add, | |
2261 | OverflowOpViaIntrinsic::Sub => Op::Sub, | |
2262 | OverflowOpViaIntrinsic::Mul => Op::Mul | |
2263 | }; | |
c34b1796 AL |
2264 | |
2265 | let bcx = | |
3157f602 | 2266 | base::with_cond(bcx, expected, |bcx| |
c34b1796 | 2267 | controlflow::trans_fail(bcx, info, |
3157f602 | 2268 | InternedString::new(ConstMathErr::Overflow(op).description()))); |
c34b1796 AL |
2269 | |
2270 | (bcx, result) | |
2271 | } | |
2272 | } | |
2273 | ||
2274 | impl OverflowOpViaInputCheck { | |
2275 | fn build_with_input_check<'blk, 'tcx>(&self, | |
2276 | bcx: Block<'blk, 'tcx>, | |
2277 | info: NodeIdAndSpan, | |
2278 | lhs_t: Ty<'tcx>, | |
2279 | lhs: ValueRef, | |
2280 | rhs: ValueRef, | |
2281 | binop_debug_loc: DebugLoc) | |
2282 | -> (Block<'blk, 'tcx>, ValueRef) | |
2283 | { | |
3157f602 XL |
2284 | use rustc_const_math::{ConstMathErr, Op}; |
2285 | ||
c34b1796 AL |
2286 | let lhs_llty = val_ty(lhs); |
2287 | let rhs_llty = val_ty(rhs); | |
2288 | ||
2289 | // Panic if any bits are set outside of bits that we always | |
2290 | // mask in. | |
2291 | // | |
2292 | // Note that the mask's value is derived from the LHS type | |
2293 | // (since that is where the 32/64 distinction is relevant) but | |
2294 | // the mask's type must match the RHS type (since they will | |
b039eaaf | 2295 | // both be fed into an and-binop) |
62682a34 | 2296 | let invert_mask = shift_mask_val(bcx, lhs_llty, rhs_llty, true); |
c34b1796 AL |
2297 | |
2298 | let outer_bits = And(bcx, rhs, invert_mask, binop_debug_loc); | |
62682a34 | 2299 | let cond = build_nonzero_check(bcx, outer_bits, binop_debug_loc); |
3157f602 | 2300 | let (result, op) = match *self { |
c34b1796 | 2301 | OverflowOpViaInputCheck::Shl => |
3157f602 | 2302 | (build_unchecked_lshift(bcx, lhs, rhs, binop_debug_loc), Op::Shl), |
c34b1796 | 2303 | OverflowOpViaInputCheck::Shr => |
3157f602 | 2304 | (build_unchecked_rshift(bcx, lhs_t, lhs, rhs, binop_debug_loc), Op::Shr) |
c34b1796 AL |
2305 | }; |
2306 | let bcx = | |
2307 | base::with_cond(bcx, cond, |bcx| | |
2308 | controlflow::trans_fail(bcx, info, | |
3157f602 | 2309 | InternedString::new(ConstMathErr::Overflow(op).description()))); |
c34b1796 AL |
2310 | |
2311 | (bcx, result) | |
2312 | } | |
2313 | } | |
2314 | ||
62682a34 SL |
2315 | // Check if an integer or vector contains a nonzero element. |
2316 | fn build_nonzero_check<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, | |
2317 | value: ValueRef, | |
2318 | binop_debug_loc: DebugLoc) -> ValueRef { | |
2319 | let llty = val_ty(value); | |
2320 | let kind = llty.kind(); | |
2321 | match kind { | |
2322 | TypeKind::Integer => ICmp(bcx, llvm::IntNE, value, C_null(llty), binop_debug_loc), | |
2323 | TypeKind::Vector => { | |
2324 | // Check if any elements of the vector are nonzero by treating | |
2325 | // it as a wide integer and checking if the integer is nonzero. | |
2326 | let width = llty.vector_length() as u64 * llty.element_type().int_width(); | |
2327 | let int_value = BitCast(bcx, value, Type::ix(bcx.ccx(), width)); | |
2328 | build_nonzero_check(bcx, int_value, binop_debug_loc) | |
2329 | }, | |
54a0048b | 2330 | _ => bug!("build_nonzero_check: expected Integer or Vector, found {:?}", kind), |
62682a34 | 2331 | } |
c34b1796 AL |
2332 | } |
2333 | ||
c34b1796 AL |
2334 | fn with_overflow_check<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, oop: OverflowOp, info: NodeIdAndSpan, |
2335 | lhs_t: Ty<'tcx>, lhs: ValueRef, | |
2336 | rhs: ValueRef, | |
2337 | binop_debug_loc: DebugLoc) | |
2338 | -> (Block<'blk, 'tcx>, ValueRef) { | |
2339 | if bcx.unreachable.get() { return (bcx, _Undef(lhs)); } | |
2340 | if bcx.ccx().check_overflow() { | |
2341 | ||
2342 | match oop.codegen_strategy() { | |
2343 | OverflowCodegen::ViaIntrinsic(oop) => | |
2344 | oop.build_intrinsic_call(bcx, info, lhs_t, lhs, rhs, binop_debug_loc), | |
2345 | OverflowCodegen::ViaInputCheck(oop) => | |
2346 | oop.build_with_input_check(bcx, info, lhs_t, lhs, rhs, binop_debug_loc), | |
2347 | } | |
2348 | } else { | |
2349 | let res = match oop { | |
2350 | OverflowOp::Add => Add(bcx, lhs, rhs, binop_debug_loc), | |
2351 | OverflowOp::Sub => Sub(bcx, lhs, rhs, binop_debug_loc), | |
2352 | OverflowOp::Mul => Mul(bcx, lhs, rhs, binop_debug_loc), | |
2353 | ||
2354 | OverflowOp::Shl => | |
2355 | build_unchecked_lshift(bcx, lhs, rhs, binop_debug_loc), | |
2356 | OverflowOp::Shr => | |
2357 | build_unchecked_rshift(bcx, lhs_t, lhs, rhs, binop_debug_loc), | |
2358 | }; | |
2359 | (bcx, res) | |
2360 | } | |
2361 | } | |
62682a34 SL |
2362 | |
2363 | /// We categorize expressions into three kinds. The distinction between | |
2364 | /// lvalue/rvalue is fundamental to the language. The distinction between the | |
2365 | /// two kinds of rvalues is an artifact of trans which reflects how we will | |
2366 | /// generate code for that kind of expression. See trans/expr.rs for more | |
2367 | /// information. | |
2368 | #[derive(Copy, Clone)] | |
2369 | enum ExprKind { | |
2370 | Lvalue, | |
2371 | RvalueDps, | |
2372 | RvalueDatum, | |
2373 | RvalueStmt | |
2374 | } | |
2375 | ||
a7813a04 | 2376 | fn expr_kind<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, expr: &hir::Expr) -> ExprKind { |
c1a9b12d | 2377 | if tcx.is_method_call(expr.id) { |
62682a34 SL |
2378 | // Overloaded operations are generally calls, and hence they are |
2379 | // generated via DPS, but there are a few exceptions: | |
2380 | return match expr.node { | |
2381 | // `a += b` has a unit result. | |
e9174d1e | 2382 | hir::ExprAssignOp(..) => ExprKind::RvalueStmt, |
62682a34 SL |
2383 | |
2384 | // the deref method invoked for `*a` always yields an `&T` | |
e9174d1e | 2385 | hir::ExprUnary(hir::UnDeref, _) => ExprKind::Lvalue, |
62682a34 SL |
2386 | |
2387 | // the index method invoked for `a[i]` always yields an `&T` | |
e9174d1e | 2388 | hir::ExprIndex(..) => ExprKind::Lvalue, |
62682a34 SL |
2389 | |
2390 | // in the general case, result could be any type, use DPS | |
2391 | _ => ExprKind::RvalueDps | |
2392 | }; | |
2393 | } | |
2394 | ||
2395 | match expr.node { | |
e9174d1e | 2396 | hir::ExprPath(..) => { |
3157f602 | 2397 | match tcx.expect_def(expr.id) { |
54a0048b SL |
2398 | // Put functions and ctors with the ADTs, as they |
2399 | // are zero-sized, so DPS is the cheapest option. | |
2400 | Def::Struct(..) | Def::Variant(..) | | |
2401 | Def::Fn(..) | Def::Method(..) => { | |
2402 | ExprKind::RvalueDps | |
62682a34 SL |
2403 | } |
2404 | ||
62682a34 SL |
2405 | // Note: there is actually a good case to be made that |
2406 | // DefArg's, particularly those of immediate type, ought to | |
2407 | // considered rvalues. | |
7453a54e SL |
2408 | Def::Static(..) | |
2409 | Def::Upvar(..) | | |
2410 | Def::Local(..) => ExprKind::Lvalue, | |
62682a34 | 2411 | |
7453a54e SL |
2412 | Def::Const(..) | |
2413 | Def::AssociatedConst(..) => ExprKind::RvalueDatum, | |
62682a34 SL |
2414 | |
2415 | def => { | |
54a0048b | 2416 | span_bug!( |
62682a34 | 2417 | expr.span, |
54a0048b SL |
2418 | "uncategorized def for expr {}: {:?}", |
2419 | expr.id, | |
2420 | def); | |
62682a34 SL |
2421 | } |
2422 | } | |
2423 | } | |
2424 | ||
9cc50fc6 SL |
2425 | hir::ExprType(ref expr, _) => { |
2426 | expr_kind(tcx, expr) | |
2427 | } | |
2428 | ||
e9174d1e SL |
2429 | hir::ExprUnary(hir::UnDeref, _) | |
2430 | hir::ExprField(..) | | |
2431 | hir::ExprTupField(..) | | |
2432 | hir::ExprIndex(..) => { | |
62682a34 SL |
2433 | ExprKind::Lvalue |
2434 | } | |
2435 | ||
e9174d1e SL |
2436 | hir::ExprCall(..) | |
2437 | hir::ExprMethodCall(..) | | |
2438 | hir::ExprStruct(..) | | |
e9174d1e SL |
2439 | hir::ExprTup(..) | |
2440 | hir::ExprIf(..) | | |
2441 | hir::ExprMatch(..) | | |
2442 | hir::ExprClosure(..) | | |
2443 | hir::ExprBlock(..) | | |
2444 | hir::ExprRepeat(..) | | |
2445 | hir::ExprVec(..) => { | |
62682a34 SL |
2446 | ExprKind::RvalueDps |
2447 | } | |
2448 | ||
9cc50fc6 | 2449 | hir::ExprLit(ref lit) if lit.node.is_str() => { |
62682a34 SL |
2450 | ExprKind::RvalueDps |
2451 | } | |
2452 | ||
e9174d1e SL |
2453 | hir::ExprBreak(..) | |
2454 | hir::ExprAgain(..) | | |
2455 | hir::ExprRet(..) | | |
2456 | hir::ExprWhile(..) | | |
2457 | hir::ExprLoop(..) | | |
2458 | hir::ExprAssign(..) | | |
2459 | hir::ExprInlineAsm(..) | | |
2460 | hir::ExprAssignOp(..) => { | |
62682a34 SL |
2461 | ExprKind::RvalueStmt |
2462 | } | |
2463 | ||
e9174d1e SL |
2464 | hir::ExprLit(_) | // Note: LitStr is carved out above |
2465 | hir::ExprUnary(..) | | |
b039eaaf | 2466 | hir::ExprBox(_) | |
e9174d1e SL |
2467 | hir::ExprAddrOf(..) | |
2468 | hir::ExprBinary(..) | | |
2469 | hir::ExprCast(..) => { | |
62682a34 SL |
2470 | ExprKind::RvalueDatum |
2471 | } | |
62682a34 SL |
2472 | } |
2473 | } |