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.
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.
11 #![allow(non_camel_case_types)]
19 use trans::cleanup::CleanupMethods;
23 use trans::debuginfo::DebugLoc;
24 use trans::expr::{Dest, Ignore, SaveIn};
26 use trans::machine::llsize_of_alloc;
27 use trans::type_::Type;
29 use middle::ty::{self, Ty};
34 use syntax::parse::token::InternedString;
36 #[derive(Copy, Clone)]
37 struct VecTypes<'tcx> {
42 impl<'tcx> VecTypes<'tcx> {
43 pub fn to_string<'a>(&self, ccx: &CrateContext<'a, 'tcx>) -> String {
44 format!("VecTypes {{unit_ty={}, llunit_ty={}}}",
46 ccx.tn().type_to_string(self.llunit_ty))
50 pub fn trans_fixed_vstore<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
53 -> Block<'blk, 'tcx> {
56 // [...] allocates a fixed-size array and moves it around "by value".
57 // In this case, it means that the caller has already given us a location
58 // to store the array of the suitable size, so all we have to do is
59 // generate the content.
61 debug!("trans_fixed_vstore(expr={:?}, dest={})",
62 expr, dest.to_string(bcx.ccx()));
64 let vt = vec_types_from_expr(bcx, expr);
67 Ignore => write_content(bcx, &vt, expr, expr, dest),
69 // lldest will have type *[T x N], but we want the type *T,
70 // so use GEP to convert:
71 let lldest = StructGEP(bcx, lldest, 0);
72 write_content(bcx, &vt, expr, expr, SaveIn(lldest))
77 /// &[...] allocates memory on the stack and writes the values into it, returning the vector (the
78 /// caller must make the reference). "..." is similar except that the memory can be statically
79 /// allocated and we return a reference (strings are always by-ref).
80 pub fn trans_slice_vec<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
81 slice_expr: &hir::Expr,
82 content_expr: &hir::Expr)
83 -> DatumBlock<'blk, 'tcx, Expr> {
88 debug!("trans_slice_vec(slice_expr={:?})",
91 let vec_ty = node_id_type(bcx, slice_expr.id);
93 // Handle the "..." case (returns a slice since strings are always unsized):
94 if let hir::ExprLit(ref lit) = content_expr.node {
95 if let ast::LitKind::Str(ref s, _) = lit.node {
96 let scratch = rvalue_scratch_datum(bcx, vec_ty, "");
97 bcx = trans_lit_str(bcx,
100 SaveIn(scratch.val));
101 return DatumBlock::new(bcx, scratch.to_expr_datum());
105 // Handle the &[...] case:
106 let vt = vec_types_from_expr(bcx, content_expr);
107 let count = elements_required(bcx, content_expr);
108 debug!(" vt={}, count={}", vt.to_string(ccx), count);
110 let fixed_ty = bcx.tcx().mk_array(vt.unit_ty, count);
112 // Always create an alloca even if zero-sized, to preserve
113 // the non-null invariant of the inner slice ptr
115 // Issue 30018: ensure state is initialized as dropped if necessary.
116 if fcx.type_needs_drop(vt.unit_ty) {
117 llfixed = base::alloc_ty_init(bcx, fixed_ty, InitAlloca::Dropped, "");
119 let uninit = InitAlloca::Uninit("fcx says vt.unit_ty is non-drop");
120 llfixed = base::alloc_ty_init(bcx, fixed_ty, uninit, "");
121 call_lifetime_start(bcx, llfixed);
125 // Arrange for the backing array to be cleaned up.
126 let cleanup_scope = cleanup::temporary_scope(bcx.tcx(), content_expr.id);
127 fcx.schedule_lifetime_end(cleanup_scope, llfixed);
128 fcx.schedule_drop_mem(cleanup_scope, llfixed, fixed_ty, None);
130 // Generate the content into the backing array.
131 // llfixed has type *[T x N], but we want the type *T,
132 // so use GEP to convert
133 bcx = write_content(bcx, &vt, slice_expr, content_expr,
134 SaveIn(StructGEP(bcx, llfixed, 0)));
137 immediate_rvalue_bcx(bcx, llfixed, vec_ty).to_expr_datumblock()
140 /// Literal strings translate to slices into static memory. This is different from
141 /// trans_slice_vstore() above because it doesn't need to copy the content anywhere.
142 pub fn trans_lit_str<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
143 lit_expr: &hir::Expr,
144 str_lit: InternedString,
146 -> Block<'blk, 'tcx> {
147 debug!("trans_lit_str(lit_expr={:?}, dest={})",
149 dest.to_string(bcx.ccx()));
154 let bytes = str_lit.len();
155 let llbytes = C_uint(bcx.ccx(), bytes);
156 let llcstr = C_cstr(bcx.ccx(), str_lit, false);
157 let llcstr = consts::ptrcast(llcstr, Type::i8p(bcx.ccx()));
158 Store(bcx, llcstr, expr::get_dataptr(bcx, lldest));
159 Store(bcx, llbytes, expr::get_meta(bcx, lldest));
165 fn write_content<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
167 vstore_expr: &hir::Expr,
168 content_expr: &hir::Expr,
170 -> Block<'blk, 'tcx> {
171 let _icx = push_ctxt("tvec::write_content");
175 debug!("write_content(vt={}, dest={}, vstore_expr={:?})",
176 vt.to_string(bcx.ccx()),
177 dest.to_string(bcx.ccx()),
180 match content_expr.node {
181 hir::ExprLit(ref lit) => {
183 ast::LitKind::Str(ref s, _) => {
185 Ignore => return bcx,
188 let llbytes = C_uint(bcx.ccx(), bytes);
189 let llcstr = C_cstr(bcx.ccx(), (*s).clone(), false);
190 base::call_memcpy(bcx,
200 bcx.tcx().sess.span_bug(content_expr.span,
201 "unexpected evec content");
205 hir::ExprVec(ref elements) => {
208 for element in elements {
209 bcx = expr::trans_into(bcx, &element, Ignore);
214 let temp_scope = fcx.push_custom_cleanup_scope();
215 for (i, element) in elements.iter().enumerate() {
216 let lleltptr = GEPi(bcx, lldest, &[i]);
217 debug!("writing index {} with lleltptr={}",
218 i, bcx.val_to_string(lleltptr));
219 bcx = expr::trans_into(bcx, &element,
221 let scope = cleanup::CustomScope(temp_scope);
222 // Issue #30822: mark memory as dropped after running destructor
223 fcx.schedule_drop_and_fill_mem(scope, lleltptr, vt.unit_ty, None);
225 fcx.pop_custom_cleanup_scope(temp_scope);
230 hir::ExprRepeat(ref element, ref count_expr) => {
233 return expr::trans_into(bcx, &element, Ignore);
236 match bcx.tcx().eval_repeat_count(&count_expr) {
237 0 => expr::trans_into(bcx, &element, Ignore),
238 1 => expr::trans_into(bcx, &element, SaveIn(lldest)),
240 let elem = unpack_datum!(bcx, expr::trans(bcx, &element));
241 let bcx = iter_vec_loop(bcx, lldest, vt,
242 C_uint(bcx.ccx(), count),
243 |set_bcx, lleltptr, _| {
244 elem.shallow_copy(set_bcx, lleltptr)
253 bcx.tcx().sess.span_bug(content_expr.span,
254 "unexpected vec content");
259 fn vec_types_from_expr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, vec_expr: &hir::Expr)
261 let vec_ty = node_id_type(bcx, vec_expr.id);
262 vec_types(bcx, vec_ty.sequence_element_type(bcx.tcx()))
265 fn vec_types<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, unit_ty: Ty<'tcx>)
269 llunit_ty: type_of::type_of(bcx.ccx(), unit_ty)
273 fn elements_required(bcx: Block, content_expr: &hir::Expr) -> usize {
274 //! Figure out the number of elements we need to store this content
276 match content_expr.node {
277 hir::ExprLit(ref lit) => {
279 ast::LitKind::Str(ref s, _) => s.len(),
281 bcx.tcx().sess.span_bug(content_expr.span,
282 "unexpected evec content")
286 hir::ExprVec(ref es) => es.len(),
287 hir::ExprRepeat(_, ref count_expr) => {
288 bcx.tcx().eval_repeat_count(&count_expr)
290 _ => bcx.tcx().sess.span_bug(content_expr.span,
291 "unexpected vec content")
295 /// Converts a fixed-length vector into the slice pair. The vector should be stored in `llval`
296 /// which should be by ref.
297 pub fn get_fixed_base_and_len(bcx: Block,
300 -> (ValueRef, ValueRef) {
303 let base = expr::get_dataptr(bcx, llval);
304 let len = C_uint(ccx, vec_length);
308 /// Converts a vector into the slice pair. The vector should be stored in `llval` which should be
309 /// by-reference. If you have a datum, you would probably prefer to call
310 /// `Datum::get_base_and_len()` which will handle any conversions for you.
311 pub fn get_base_and_len<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
314 -> (ValueRef, ValueRef) {
318 ty::TyArray(_, n) => get_fixed_base_and_len(bcx, llval, n),
319 ty::TySlice(_) | ty::TyStr => {
320 let base = Load(bcx, expr::get_dataptr(bcx, llval));
321 let len = Load(bcx, expr::get_meta(bcx, llval));
325 // Only used for pattern matching.
326 ty::TyBox(ty) | ty::TyRef(_, ty::TypeAndMut{ty, ..}) => {
327 let inner = if type_is_sized(bcx.tcx(), ty) {
332 get_base_and_len(bcx, inner, ty)
334 _ => ccx.sess().bug("unexpected type in get_base_and_len"),
338 fn iter_vec_loop<'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>,
343 -> Block<'blk, 'tcx> where
344 F: FnOnce(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>,
346 let _icx = push_ctxt("tvec::iter_vec_loop");
348 if bcx.unreachable.get() {
353 let loop_bcx = fcx.new_temp_block("expr_repeat");
354 let next_bcx = fcx.new_temp_block("expr_repeat: next");
356 Br(bcx, loop_bcx.llbb, DebugLoc::None);
358 let loop_counter = Phi(loop_bcx, bcx.ccx().int_type(),
359 &[C_uint(bcx.ccx(), 0 as usize)], &[bcx.llbb]);
363 let lleltptr = if llsize_of_alloc(bcx.ccx(), vt.llunit_ty) == 0 {
366 InBoundsGEP(bcx, data_ptr, &[loop_counter])
368 let bcx = f(bcx, lleltptr, vt.unit_ty);
369 let plusone = Add(bcx, loop_counter, C_uint(bcx.ccx(), 1usize), DebugLoc::None);
370 AddIncomingToPhi(loop_counter, plusone, bcx.llbb);
372 let cond_val = ICmp(bcx, llvm::IntULT, plusone, count, DebugLoc::None);
373 CondBr(bcx, cond_val, loop_bcx.llbb, next_bcx.llbb, DebugLoc::None);
378 pub fn iter_vec_raw<'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>,
383 -> Block<'blk, 'tcx> where
384 F: FnOnce(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>,
386 let _icx = push_ctxt("tvec::iter_vec_raw");
389 let vt = vec_types(bcx, unit_ty);
391 if llsize_of_alloc(bcx.ccx(), vt.llunit_ty) == 0 {
392 // Special-case vectors with elements of size 0 so they don't go out of bounds (#9890)
393 iter_vec_loop(bcx, data_ptr, &vt, len, f)
395 // Calculate the last pointer address we want to handle.
396 let data_end_ptr = InBoundsGEP(bcx, data_ptr, &[len]);
398 // Now perform the iteration.
399 let header_bcx = fcx.new_temp_block("iter_vec_loop_header");
400 Br(bcx, header_bcx.llbb, DebugLoc::None);
402 Phi(header_bcx, val_ty(data_ptr), &[data_ptr], &[bcx.llbb]);
404 ICmp(header_bcx, llvm::IntULT, data_ptr, data_end_ptr, DebugLoc::None);
405 let body_bcx = fcx.new_temp_block("iter_vec_loop_body");
406 let next_bcx = fcx.new_temp_block("iter_vec_next");
407 CondBr(header_bcx, not_yet_at_end, body_bcx.llbb, next_bcx.llbb, DebugLoc::None);
408 let body_bcx = f(body_bcx, data_ptr, unit_ty);
409 AddIncomingToPhi(data_ptr, InBoundsGEP(body_bcx, data_ptr,
410 &[C_int(bcx.ccx(), 1)]),
412 Br(body_bcx, header_bcx.llbb, DebugLoc::None);