/
consts.rs
696 lines (667 loc) · 30.6 KB
/
consts.rs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use back::abi;
use llvm;
use llvm::{ConstFCmp, ConstICmp, SetLinkage, PrivateLinkage, ValueRef, Bool, True, False};
use llvm::{IntEQ, IntNE, IntUGT, IntUGE, IntULT, IntULE, IntSGT, IntSGE, IntSLT, IntSLE,
RealOEQ, RealOGT, RealOGE, RealOLT, RealOLE, RealONE};
use metadata::csearch;
use middle::const_eval;
use middle::def;
use middle::trans::adt;
use middle::trans::base;
use middle::trans::base::push_ctxt;
use middle::trans::closure;
use middle::trans::common::*;
use middle::trans::consts;
use middle::trans::expr;
use middle::trans::inline;
use middle::trans::machine;
use middle::trans::type_::Type;
use middle::trans::type_of;
use middle::trans::debuginfo;
use middle::ty;
use util::ppaux::{Repr, ty_to_string};
use std::c_str::ToCStr;
use std::gc::Gc;
use std::vec;
use libc::c_uint;
use syntax::{ast, ast_util};
pub fn const_lit(cx: &CrateContext, e: &ast::Expr, lit: ast::Lit)
-> ValueRef {
let _icx = push_ctxt("trans_lit");
debug!("const_lit: {}", lit);
match lit.node {
ast::LitByte(b) => C_integral(Type::uint_from_ty(cx, ast::TyU8), b as u64, false),
ast::LitChar(i) => C_integral(Type::char(cx), i as u64, false),
ast::LitInt(i, ast::SignedIntLit(t, _)) => {
C_integral(Type::int_from_ty(cx, t), i, true)
}
ast::LitInt(u, ast::UnsignedIntLit(t)) => {
C_integral(Type::uint_from_ty(cx, t), u, false)
}
ast::LitInt(i, ast::UnsuffixedIntLit(_)) => {
let lit_int_ty = ty::node_id_to_type(cx.tcx(), e.id);
match ty::get(lit_int_ty).sty {
ty::ty_int(t) => {
C_integral(Type::int_from_ty(cx, t), i as u64, true)
}
ty::ty_uint(t) => {
C_integral(Type::uint_from_ty(cx, t), i as u64, false)
}
_ => cx.sess().span_bug(lit.span,
format!("integer literal has type {} (expected int \
or uint)",
ty_to_string(cx.tcx(), lit_int_ty)).as_slice())
}
}
ast::LitFloat(ref fs, t) => {
C_floating(fs.get(), Type::float_from_ty(cx, t))
}
ast::LitFloatUnsuffixed(ref fs) => {
let lit_float_ty = ty::node_id_to_type(cx.tcx(), e.id);
match ty::get(lit_float_ty).sty {
ty::ty_float(t) => {
C_floating(fs.get(), Type::float_from_ty(cx, t))
}
_ => {
cx.sess().span_bug(lit.span,
"floating point literal doesn't have the right type");
}
}
}
ast::LitBool(b) => C_bool(cx, b),
ast::LitNil => C_nil(cx),
ast::LitStr(ref s, _) => C_str_slice(cx, (*s).clone()),
ast::LitBinary(ref data) => C_binary_slice(cx, data.as_slice()),
}
}
pub fn const_ptrcast(cx: &CrateContext, a: ValueRef, t: Type) -> ValueRef {
unsafe {
let b = llvm::LLVMConstPointerCast(a, t.ptr_to().to_ref());
assert!(cx.const_globals.borrow_mut().insert(b as int, a));
b
}
}
// Helper function because we don't have tuple-swizzling.
fn first_two<R, S, T>((a, b, _): (R, S, T)) -> (R, S) {
(a, b)
}
fn const_vec(cx: &CrateContext, e: &ast::Expr,
es: &[Gc<ast::Expr>], is_local: bool) -> (ValueRef, Type, bool) {
let vec_ty = ty::expr_ty(cx.tcx(), e);
let unit_ty = ty::sequence_element_type(cx.tcx(), vec_ty);
let llunitty = type_of::type_of(cx, unit_ty);
let (vs, inlineable) = vec::unzip(es.iter().map(|e| first_two(const_expr(cx, &**e, is_local))));
// If the vector contains enums, an LLVM array won't work.
let v = if vs.iter().any(|vi| val_ty(*vi) != llunitty) {
C_struct(cx, vs.as_slice(), false)
} else {
C_array(llunitty, vs.as_slice())
};
(v, llunitty, inlineable.iter().fold(true, |a, &b| a && b))
}
pub fn const_addr_of(cx: &CrateContext, cv: ValueRef, mutbl: ast::Mutability) -> ValueRef {
unsafe {
let gv = "const".with_c_str(|name| {
llvm::LLVMAddGlobal(cx.llmod, val_ty(cv).to_ref(), name)
});
llvm::LLVMSetInitializer(gv, cv);
llvm::LLVMSetGlobalConstant(gv,
if mutbl == ast::MutImmutable {True} else {False});
SetLinkage(gv, PrivateLinkage);
gv
}
}
fn const_deref_ptr(cx: &CrateContext, v: ValueRef) -> ValueRef {
let v = match cx.const_globals.borrow().find(&(v as int)) {
Some(&v) => v,
None => v
};
unsafe {
llvm::LLVMGetInitializer(v)
}
}
fn const_deref_newtype(cx: &CrateContext, v: ValueRef, t: ty::t)
-> ValueRef {
let repr = adt::represent_type(cx, t);
adt::const_get_field(cx, &*repr, v, 0, 0)
}
fn const_deref(cx: &CrateContext, v: ValueRef, t: ty::t, explicit: bool)
-> (ValueRef, ty::t) {
match ty::deref(t, explicit) {
Some(ref mt) => {
match ty::get(t).sty {
ty::ty_ptr(mt) | ty::ty_rptr(_, mt) => {
if ty::type_is_sized(cx.tcx(), mt.ty) {
(const_deref_ptr(cx, v), mt.ty)
} else {
// Derefing a fat pointer does not change the representation,
// just the type to ty_open.
(v, ty::mk_open(cx.tcx(), mt.ty))
}
}
ty::ty_enum(..) | ty::ty_struct(..) => {
assert!(mt.mutbl != ast::MutMutable);
(const_deref_newtype(cx, v, t), mt.ty)
}
_ => {
cx.sess().bug(format!("unexpected dereferenceable type {}",
ty_to_string(cx.tcx(), t)).as_slice())
}
}
}
None => {
cx.sess().bug(format!("can't dereference const of type {}",
ty_to_string(cx.tcx(), t)).as_slice())
}
}
}
pub fn get_const_val(cx: &CrateContext,
mut def_id: ast::DefId) -> (ValueRef, bool) {
let contains_key = cx.const_values.borrow().contains_key(&def_id.node);
if !ast_util::is_local(def_id) || !contains_key {
if !ast_util::is_local(def_id) {
def_id = inline::maybe_instantiate_inline(cx, def_id);
}
match cx.tcx.map.expect_item(def_id.node).node {
ast::ItemStatic(_, ast::MutImmutable, _) => {
trans_const(cx, ast::MutImmutable, def_id.node);
}
_ => {}
}
}
(cx.const_values.borrow().get_copy(&def_id.node),
!cx.non_inlineable_statics.borrow().contains(&def_id.node))
}
pub fn const_expr(cx: &CrateContext, e: &ast::Expr, is_local: bool) -> (ValueRef, bool, ty::t) {
let (llconst, inlineable) = const_expr_unadjusted(cx, e, is_local);
let mut llconst = llconst;
let mut inlineable = inlineable;
let ety = ty::expr_ty(cx.tcx(), e);
let mut ety_adjusted = ty::expr_ty_adjusted(cx.tcx(), e);
let opt_adj = cx.tcx.adjustments.borrow().find_copy(&e.id);
match opt_adj {
None => { }
Some(adj) => {
match adj {
ty::AutoAddEnv(ty::RegionTraitStore(ty::ReStatic, _)) => {
let def = ty::resolve_expr(cx.tcx(), e);
let wrapper = closure::get_wrapper_for_bare_fn(cx,
ety_adjusted,
def,
llconst,
is_local);
llconst = C_struct(cx, [wrapper, C_null(Type::i8p(cx))], false)
}
ty::AutoAddEnv(store) => {
cx.sess()
.span_bug(e.span,
format!("unexpected static function: {:?}",
store).as_slice())
}
ty::AutoDerefRef(ref adj) => {
let mut ty = ety;
// Save the last autoderef in case we can avoid it.
for _ in range(0, adj.autoderefs-1) {
let (dv, dt) = const_deref(cx, llconst, ty, false);
llconst = dv;
ty = dt;
}
match adj.autoref {
None => {
let (dv, dt) = const_deref(cx, llconst, ty, false);
llconst = dv;
// If we derefed a fat pointer then we will have an
// open type here. So we need to update the type with
// the one returned from const_deref.
ety_adjusted = dt;
}
Some(ref autoref) => {
match *autoref {
ty::AutoUnsafe(_, None) |
ty::AutoPtr(ty::ReStatic, _, None) => {
// Don't copy data to do a deref+ref
// (i.e., skip the last auto-deref).
if adj.autoderefs == 0 {
inlineable = false;
llconst = const_addr_of(cx, llconst, ast::MutImmutable);
}
}
ty::AutoPtr(ty::ReStatic, _, Some(box ty::AutoUnsize(..))) => {
if adj.autoderefs > 0 {
// Seeing as we are deref'ing here and take a reference
// again to make the pointer part of the far pointer below,
// we just skip the whole thing. We still need the type
// though. This works even if we don't need to deref
// because of byref semantics. Note that this is not just
// an optimisation, it is necessary for mutable vectors to
// work properly.
let (_, dt) = const_deref(cx, llconst, ty, false);
ty = dt;
}
match ty::get(ty).sty {
ty::ty_vec(unit_ty, Some(len)) => {
inlineable = false;
let llunitty = type_of::type_of(cx, unit_ty);
let llptr = const_ptrcast(cx, llconst, llunitty);
assert_eq!(abi::slice_elt_base, 0);
assert_eq!(abi::slice_elt_len, 1);
llconst = C_struct(cx, [
llptr,
C_uint(cx, len)
], false);
}
_ => cx.sess().span_bug(e.span,
format!("unimplemented type in const unsize: {}",
ty_to_string(cx.tcx(), ty)).as_slice())
}
}
_ => {
cx.sess()
.span_bug(e.span,
format!("unimplemented const \
autoref {:?}",
autoref).as_slice())
}
}
}
}
}
}
}
}
let llty = type_of::sizing_type_of(cx, ety_adjusted);
let csize = machine::llsize_of_alloc(cx, val_ty(llconst));
let tsize = machine::llsize_of_alloc(cx, llty);
if csize != tsize {
unsafe {
// FIXME these values could use some context
llvm::LLVMDumpValue(llconst);
llvm::LLVMDumpValue(C_undef(llty));
}
cx.sess().bug(format!("const {} of type {} has size {} instead of {}",
e.repr(cx.tcx()), ty_to_string(cx.tcx(), ety),
csize, tsize).as_slice());
}
(llconst, inlineable, ety_adjusted)
}
// the bool returned is whether this expression can be inlined into other crates
// if it's assigned to a static.
fn const_expr_unadjusted(cx: &CrateContext, e: &ast::Expr,
is_local: bool) -> (ValueRef, bool) {
let map_list = |exprs: &[Gc<ast::Expr>]| {
exprs.iter().map(|e| first_two(const_expr(cx, &**e, is_local)))
.fold((Vec::new(), true),
|(l, all_inlineable), (val, inlineable)| {
(l.append_one(val), all_inlineable && inlineable)
})
};
unsafe {
let _icx = push_ctxt("const_expr");
return match e.node {
ast::ExprLit(ref lit) => {
(consts::const_lit(cx, e, (**lit).clone()), true)
}
ast::ExprBinary(b, ref e1, ref e2) => {
let (te1, _, _) = const_expr(cx, &**e1, is_local);
let (te2, _, _) = const_expr(cx, &**e2, is_local);
let te2 = base::cast_shift_const_rhs(b, te1, te2);
/* Neither type is bottom, and we expect them to be unified
* already, so the following is safe. */
let ty = ty::expr_ty(cx.tcx(), &**e1);
let is_float = ty::type_is_fp(ty);
let signed = ty::type_is_signed(ty);
return (match b {
ast::BiAdd => {
if is_float { llvm::LLVMConstFAdd(te1, te2) }
else { llvm::LLVMConstAdd(te1, te2) }
}
ast::BiSub => {
if is_float { llvm::LLVMConstFSub(te1, te2) }
else { llvm::LLVMConstSub(te1, te2) }
}
ast::BiMul => {
if is_float { llvm::LLVMConstFMul(te1, te2) }
else { llvm::LLVMConstMul(te1, te2) }
}
ast::BiDiv => {
if is_float { llvm::LLVMConstFDiv(te1, te2) }
else if signed { llvm::LLVMConstSDiv(te1, te2) }
else { llvm::LLVMConstUDiv(te1, te2) }
}
ast::BiRem => {
if is_float { llvm::LLVMConstFRem(te1, te2) }
else if signed { llvm::LLVMConstSRem(te1, te2) }
else { llvm::LLVMConstURem(te1, te2) }
}
ast::BiAnd => llvm::LLVMConstAnd(te1, te2),
ast::BiOr => llvm::LLVMConstOr(te1, te2),
ast::BiBitXor => llvm::LLVMConstXor(te1, te2),
ast::BiBitAnd => llvm::LLVMConstAnd(te1, te2),
ast::BiBitOr => llvm::LLVMConstOr(te1, te2),
ast::BiShl => llvm::LLVMConstShl(te1, te2),
ast::BiShr => {
if signed { llvm::LLVMConstAShr(te1, te2) }
else { llvm::LLVMConstLShr(te1, te2) }
}
ast::BiEq => {
if is_float { ConstFCmp(RealOEQ, te1, te2) }
else { ConstICmp(IntEQ, te1, te2) }
},
ast::BiLt => {
if is_float { ConstFCmp(RealOLT, te1, te2) }
else {
if signed { ConstICmp(IntSLT, te1, te2) }
else { ConstICmp(IntULT, te1, te2) }
}
},
ast::BiLe => {
if is_float { ConstFCmp(RealOLE, te1, te2) }
else {
if signed { ConstICmp(IntSLE, te1, te2) }
else { ConstICmp(IntULE, te1, te2) }
}
},
ast::BiNe => {
if is_float { ConstFCmp(RealONE, te1, te2) }
else { ConstICmp(IntNE, te1, te2) }
},
ast::BiGe => {
if is_float { ConstFCmp(RealOGE, te1, te2) }
else {
if signed { ConstICmp(IntSGE, te1, te2) }
else { ConstICmp(IntUGE, te1, te2) }
}
},
ast::BiGt => {
if is_float { ConstFCmp(RealOGT, te1, te2) }
else {
if signed { ConstICmp(IntSGT, te1, te2) }
else { ConstICmp(IntUGT, te1, te2) }
}
},
}, true)
},
ast::ExprUnary(u, ref e) => {
let (te, _, _) = const_expr(cx, &**e, is_local);
let ty = ty::expr_ty(cx.tcx(), &**e);
let is_float = ty::type_is_fp(ty);
return (match u {
ast::UnBox | ast::UnUniq | ast::UnDeref => {
let (dv, _dt) = const_deref(cx, te, ty, true);
dv
}
ast::UnNot => llvm::LLVMConstNot(te),
ast::UnNeg => {
if is_float { llvm::LLVMConstFNeg(te) }
else { llvm::LLVMConstNeg(te) }
}
}, true)
}
ast::ExprField(ref base, field, _) => {
let (bv, inlineable, bt) = const_expr(cx, &**base, is_local);
let brepr = adt::represent_type(cx, bt);
expr::with_field_tys(cx.tcx(), bt, None, |discr, field_tys| {
let ix = ty::field_idx_strict(cx.tcx(), field.node.name, field_tys);
(adt::const_get_field(cx, &*brepr, bv, discr, ix), inlineable)
})
}
ast::ExprIndex(ref base, ref index) => {
let (bv, inlineable, bt) = const_expr(cx, &**base, is_local);
let iv = match const_eval::eval_const_expr(cx.tcx(), &**index) {
const_eval::const_int(i) => i as u64,
const_eval::const_uint(u) => u,
_ => cx.sess().span_bug(index.span,
"index is not an integer-constant expression")
};
let (arr, len) = match ty::get(bt).sty {
ty::ty_vec(_, Some(u)) => (bv, C_uint(cx, u)),
ty::ty_open(ty) => match ty::get(ty).sty {
ty::ty_vec(_, None) | ty::ty_str => {
let e1 = const_get_elt(cx, bv, [0]);
(const_deref_ptr(cx, e1), const_get_elt(cx, bv, [1]))
},
_ => cx.sess().span_bug(base.span,
format!("index-expr base must be a vector \
or string type, found {}",
ty_to_string(cx.tcx(), bt)).as_slice())
},
ty::ty_rptr(_, mt) => match ty::get(mt.ty).sty {
ty::ty_vec(_, Some(u)) => {
(const_deref_ptr(cx, bv), C_uint(cx, u))
},
_ => cx.sess().span_bug(base.span,
format!("index-expr base must be a vector \
or string type, found {}",
ty_to_string(cx.tcx(), bt)).as_slice())
},
_ => cx.sess().span_bug(base.span,
format!("index-expr base must be a vector \
or string type, found {}",
ty_to_string(cx.tcx(), bt)).as_slice())
};
let len = llvm::LLVMConstIntGetZExtValue(len) as u64;
let len = match ty::get(bt).sty {
ty::ty_uniq(ty) | ty::ty_rptr(_, ty::mt{ty, ..}) => match ty::get(ty).sty {
ty::ty_str => {
assert!(len > 0);
len - 1
}
_ => len
},
_ => len
};
if iv >= len {
// FIXME #3170: report this earlier on in the const-eval
// pass. Reporting here is a bit late.
cx.sess().span_err(e.span,
"const index-expr is out of bounds");
}
(const_get_elt(cx, arr, [iv as c_uint]), inlineable)
}
ast::ExprCast(ref base, _) => {
let ety = ty::expr_ty(cx.tcx(), e);
let llty = type_of::type_of(cx, ety);
let (v, inlineable, basety) = const_expr(cx, &**base, is_local);
return (match (expr::cast_type_kind(cx.tcx(), basety),
expr::cast_type_kind(cx.tcx(), ety)) {
(expr::cast_integral, expr::cast_integral) => {
let s = ty::type_is_signed(basety) as Bool;
llvm::LLVMConstIntCast(v, llty.to_ref(), s)
}
(expr::cast_integral, expr::cast_float) => {
if ty::type_is_signed(basety) {
llvm::LLVMConstSIToFP(v, llty.to_ref())
} else {
llvm::LLVMConstUIToFP(v, llty.to_ref())
}
}
(expr::cast_float, expr::cast_float) => {
llvm::LLVMConstFPCast(v, llty.to_ref())
}
(expr::cast_float, expr::cast_integral) => {
if ty::type_is_signed(ety) { llvm::LLVMConstFPToSI(v, llty.to_ref()) }
else { llvm::LLVMConstFPToUI(v, llty.to_ref()) }
}
(expr::cast_enum, expr::cast_integral) => {
let repr = adt::represent_type(cx, basety);
let discr = adt::const_get_discrim(cx, &*repr, v);
let iv = C_integral(cx.int_type, discr, false);
let ety_cast = expr::cast_type_kind(cx.tcx(), ety);
match ety_cast {
expr::cast_integral => {
let s = ty::type_is_signed(ety) as Bool;
llvm::LLVMConstIntCast(iv, llty.to_ref(), s)
}
_ => cx.sess().bug("enum cast destination is not \
integral")
}
}
(expr::cast_pointer, expr::cast_pointer) => {
llvm::LLVMConstPointerCast(v, llty.to_ref())
}
(expr::cast_integral, expr::cast_pointer) => {
llvm::LLVMConstIntToPtr(v, llty.to_ref())
}
_ => {
cx.sess().impossible_case(e.span,
"bad combination of types for cast")
}
}, inlineable)
}
ast::ExprAddrOf(mutbl, ref sub) => {
let (e, _, _) = const_expr(cx, &**sub, is_local);
(const_addr_of(cx, e, mutbl), false)
}
ast::ExprTup(ref es) => {
let ety = ty::expr_ty(cx.tcx(), e);
let repr = adt::represent_type(cx, ety);
let (vals, inlineable) = map_list(es.as_slice());
(adt::trans_const(cx, &*repr, 0, vals.as_slice()), inlineable)
}
ast::ExprStruct(_, ref fs, ref base_opt) => {
let ety = ty::expr_ty(cx.tcx(), e);
let repr = adt::represent_type(cx, ety);
let tcx = cx.tcx();
let base_val = match *base_opt {
Some(ref base) => Some(const_expr(cx, &**base, is_local)),
None => None
};
expr::with_field_tys(tcx, ety, Some(e.id), |discr, field_tys| {
let (cs, inlineable) = vec::unzip(field_tys.iter().enumerate()
.map(|(ix, &field_ty)| {
match fs.iter().find(|f| field_ty.ident.name == f.ident.node.name) {
Some(ref f) => first_two(const_expr(cx, &*f.expr, is_local)),
None => {
match base_val {
Some((bv, inlineable, _)) => {
(adt::const_get_field(cx, &*repr, bv, discr, ix),
inlineable)
}
None => cx.sess().span_bug(e.span, "missing struct field")
}
}
}
}));
(adt::trans_const(cx, &*repr, discr, cs.as_slice()),
inlineable.iter().fold(true, |a, &b| a && b))
})
}
ast::ExprVec(ref es) => {
let (v, _, inlineable) = const_vec(cx,
e,
es.as_slice(),
is_local);
(v, inlineable)
}
ast::ExprRepeat(ref elem, ref count) => {
let vec_ty = ty::expr_ty(cx.tcx(), e);
let unit_ty = ty::sequence_element_type(cx.tcx(), vec_ty);
let llunitty = type_of::type_of(cx, unit_ty);
let n = match const_eval::eval_const_expr(cx.tcx(), &**count) {
const_eval::const_int(i) => i as uint,
const_eval::const_uint(i) => i as uint,
_ => cx.sess().span_bug(count.span, "count must be integral const expression.")
};
let vs = Vec::from_elem(n, const_expr(cx, &**elem, is_local).val0());
let v = if vs.iter().any(|vi| val_ty(*vi) != llunitty) {
C_struct(cx, vs.as_slice(), false)
} else {
C_array(llunitty, vs.as_slice())
};
(v, true)
}
ast::ExprPath(ref pth) => {
// Assert that there are no type parameters in this path.
assert!(pth.segments.iter().all(|seg| seg.types.is_empty()));
let opt_def = cx.tcx().def_map.borrow().find_copy(&e.id);
match opt_def {
Some(def::DefFn(def_id, _fn_style)) => {
if !ast_util::is_local(def_id) {
let ty = csearch::get_type(cx.tcx(), def_id).ty;
(base::trans_external_path(cx, def_id, ty), true)
} else {
assert!(ast_util::is_local(def_id));
(base::get_item_val(cx, def_id.node), true)
}
}
Some(def::DefStatic(def_id, false)) => {
get_const_val(cx, def_id)
}
Some(def::DefVariant(enum_did, variant_did, _)) => {
let ety = ty::expr_ty(cx.tcx(), e);
let repr = adt::represent_type(cx, ety);
let vinfo = ty::enum_variant_with_id(cx.tcx(),
enum_did,
variant_did);
(adt::trans_const(cx, &*repr, vinfo.disr_val, []), true)
}
Some(def::DefStruct(_)) => {
let ety = ty::expr_ty(cx.tcx(), e);
let llty = type_of::type_of(cx, ety);
(C_null(llty), true)
}
_ => {
cx.sess().span_bug(e.span, "expected a const, fn, struct, or variant def")
}
}
}
ast::ExprCall(callee, ref args) => {
let opt_def = cx.tcx().def_map.borrow().find_copy(&callee.id);
match opt_def {
Some(def::DefStruct(_)) => {
let ety = ty::expr_ty(cx.tcx(), e);
let repr = adt::represent_type(cx, ety);
let (arg_vals, inlineable) = map_list(args.as_slice());
(adt::trans_const(cx, &*repr, 0, arg_vals.as_slice()),
inlineable)
}
Some(def::DefVariant(enum_did, variant_did, _)) => {
let ety = ty::expr_ty(cx.tcx(), e);
let repr = adt::represent_type(cx, ety);
let vinfo = ty::enum_variant_with_id(cx.tcx(),
enum_did,
variant_did);
let (arg_vals, inlineable) = map_list(args.as_slice());
(adt::trans_const(cx,
&*repr,
vinfo.disr_val,
arg_vals.as_slice()), inlineable)
}
_ => cx.sess().span_bug(e.span, "expected a struct or variant def")
}
}
ast::ExprParen(ref e) => first_two(const_expr(cx, &**e, is_local)),
ast::ExprBlock(ref block) => {
match block.expr {
Some(ref expr) => first_two(const_expr(cx, &**expr, is_local)),
None => (C_nil(cx), true)
}
}
_ => cx.sess().span_bug(e.span,
"bad constant expression type in consts::const_expr")
};
}
}
pub fn trans_const(ccx: &CrateContext, m: ast::Mutability, id: ast::NodeId) {
unsafe {
let _icx = push_ctxt("trans_const");
let g = base::get_item_val(ccx, id);
// At this point, get_item_val has already translated the
// constant's initializer to determine its LLVM type.
let v = ccx.const_values.borrow().get_copy(&id);
llvm::LLVMSetInitializer(g, v);
if m != ast::MutMutable {
llvm::LLVMSetGlobalConstant(g, True);
}
debuginfo::create_global_var_metadata(ccx, id, g);
}
}