rust/src/librustc/middle/trans/tvec.rs
Brian Koropoff 8384dd9357 Fix ICE translating array repeat expr of non-Copy type
The type checker permits an array repeat expression of non-Copy
type if the count is 1, but trans asserts on it prior to this
change.

Closes #18425
2014-10-29 21:45:35 -07:00

538 lines
20 KiB
Rust

// Copyright 2012-2014 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.
#![allow(non_camel_case_types)]
use back::abi;
use llvm;
use llvm::{ValueRef};
use middle::trans::base::*;
use middle::trans::base;
use middle::trans::build::*;
use middle::trans::cleanup;
use middle::trans::cleanup::CleanupMethods;
use middle::trans::common::*;
use middle::trans::datum::*;
use middle::trans::expr::{Dest, Ignore, SaveIn};
use middle::trans::expr;
use middle::trans::glue;
use middle::trans::machine;
use middle::trans::machine::{nonzero_llsize_of, llsize_of_alloc};
use middle::trans::type_::Type;
use middle::trans::type_of;
use middle::ty;
use util::ppaux::ty_to_string;
use syntax::ast;
use syntax::parse::token::InternedString;
fn get_len(bcx: Block, vptr: ValueRef) -> ValueRef {
let _icx = push_ctxt("tvec::get_lenl");
Load(bcx, expr::get_len(bcx, vptr))
}
fn get_dataptr(bcx: Block, vptr: ValueRef) -> ValueRef {
let _icx = push_ctxt("tvec::get_dataptr");
Load(bcx, expr::get_dataptr(bcx, vptr))
}
pub fn pointer_add_byte(bcx: Block, ptr: ValueRef, bytes: ValueRef) -> ValueRef {
let _icx = push_ctxt("tvec::pointer_add_byte");
let old_ty = val_ty(ptr);
let bptr = PointerCast(bcx, ptr, Type::i8p(bcx.ccx()));
return PointerCast(bcx, InBoundsGEP(bcx, bptr, [bytes]), old_ty);
}
pub fn make_drop_glue_unboxed<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
vptr: ValueRef,
unit_ty: ty::t,
should_deallocate: bool)
-> Block<'blk, 'tcx> {
let not_null = IsNotNull(bcx, vptr);
with_cond(bcx, not_null, |bcx| {
let ccx = bcx.ccx();
let tcx = bcx.tcx();
let _icx = push_ctxt("tvec::make_drop_glue_unboxed");
let dataptr = get_dataptr(bcx, vptr);
let bcx = if ty::type_needs_drop(tcx, unit_ty) {
let len = get_len(bcx, vptr);
iter_vec_raw(bcx, dataptr, unit_ty, len, |bb, vv, tt| glue::drop_ty(bb, vv, tt, None))
} else {
bcx
};
if should_deallocate {
let llty = type_of::type_of(ccx, unit_ty);
let unit_size = llsize_of_alloc(ccx, llty);
if unit_size != 0 {
let len = get_len(bcx, vptr);
let not_empty = ICmp(bcx, llvm::IntNE, len, C_uint(ccx, 0u));
with_cond(bcx, not_empty, |bcx| {
let llalign = C_uint(ccx, machine::llalign_of_min(ccx, llty));
let size = Mul(bcx, C_uint(ccx, unit_size), len);
glue::trans_exchange_free_dyn(bcx, dataptr, size, llalign)
})
} else {
bcx
}
} else {
bcx
}
})
}
pub struct VecTypes {
pub unit_ty: ty::t,
pub llunit_ty: Type,
pub llunit_size: ValueRef,
pub llunit_alloc_size: u64
}
impl VecTypes {
pub fn to_string(&self, ccx: &CrateContext) -> String {
format!("VecTypes {{unit_ty={}, llunit_ty={}, \
llunit_size={}, llunit_alloc_size={}}}",
ty_to_string(ccx.tcx(), self.unit_ty),
ccx.tn().type_to_string(self.llunit_ty),
ccx.tn().val_to_string(self.llunit_size),
self.llunit_alloc_size)
}
}
pub fn trans_fixed_vstore<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
expr: &ast::Expr,
dest: expr::Dest)
-> Block<'blk, 'tcx> {
//!
//
// [...] allocates a fixed-size array and moves it around "by value".
// In this case, it means that the caller has already given us a location
// to store the array of the suitable size, so all we have to do is
// generate the content.
debug!("trans_fixed_vstore(expr={}, dest={})",
bcx.expr_to_string(expr), dest.to_string(bcx.ccx()));
let vt = vec_types_from_expr(bcx, expr);
return match dest {
Ignore => write_content(bcx, &vt, expr, expr, dest),
SaveIn(lldest) => {
// lldest will have type *[T x N], but we want the type *T,
// so use GEP to convert:
let lldest = GEPi(bcx, lldest, [0, 0]);
write_content(bcx, &vt, expr, expr, SaveIn(lldest))
}
};
}
pub fn trans_slice_vec<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
slice_expr: &ast::Expr,
content_expr: &ast::Expr)
-> DatumBlock<'blk, 'tcx, Expr> {
/*!
* &[...] allocates memory on the stack and writes the values into it,
* returning the vector (the caller must make the reference). "..." is
* similar except that the memory can be statically allocated and we return
* a reference (strings are always by-ref).
*/
let fcx = bcx.fcx;
let ccx = fcx.ccx;
let mut bcx = bcx;
debug!("trans_slice_vec(slice_expr={})",
bcx.expr_to_string(slice_expr));
let vec_ty = node_id_type(bcx, slice_expr.id);
// Handle the "..." case (returns a slice since strings are always unsized):
match content_expr.node {
ast::ExprLit(ref lit) => {
match lit.node {
ast::LitStr(ref s, _) => {
let scratch = rvalue_scratch_datum(bcx, vec_ty, "");
bcx = trans_lit_str(bcx,
content_expr,
s.clone(),
SaveIn(scratch.val));
return DatumBlock::new(bcx, scratch.to_expr_datum());
}
_ => {}
}
}
_ => {}
}
// Handle the &[...] case:
let vt = vec_types_from_expr(bcx, content_expr);
let count = elements_required(bcx, content_expr);
debug!(" vt={}, count={}", vt.to_string(ccx), count);
let llcount = C_uint(ccx, count);
let fixed_ty = ty::mk_vec(bcx.tcx(),
vt.unit_ty,
Some(count));
let llfixed_ty = type_of::type_of(bcx.ccx(), fixed_ty).ptr_to();
let llfixed = if count == 0 {
// Just create a zero-sized alloca to preserve
// the non-null invariant of the inner slice ptr
let llfixed = base::arrayalloca(bcx, vt.llunit_ty, llcount);
BitCast(bcx, llfixed, llfixed_ty)
} else {
// Make a fixed-length backing array and allocate it on the stack.
let llfixed = base::arrayalloca(bcx, vt.llunit_ty, llcount);
// Arrange for the backing array to be cleaned up.
let llfixed_casted = BitCast(bcx, llfixed, llfixed_ty);
let cleanup_scope = cleanup::temporary_scope(bcx.tcx(), content_expr.id);
fcx.schedule_lifetime_end(cleanup_scope, llfixed_casted);
fcx.schedule_drop_mem(cleanup_scope, llfixed_casted, fixed_ty);
// Generate the content into the backing array.
bcx = write_content(bcx, &vt, slice_expr,
content_expr, SaveIn(llfixed));
llfixed_casted
};
immediate_rvalue_bcx(bcx, llfixed, vec_ty).to_expr_datumblock()
}
pub fn trans_lit_str<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
lit_expr: &ast::Expr,
str_lit: InternedString,
dest: Dest)
-> Block<'blk, 'tcx> {
/*!
* Literal strings translate to slices into static memory. This is
* different from trans_slice_vstore() above because it doesn't need to copy
* the content anywhere.
*/
debug!("trans_lit_str(lit_expr={}, dest={})",
bcx.expr_to_string(lit_expr),
dest.to_string(bcx.ccx()));
match dest {
Ignore => bcx,
SaveIn(lldest) => {
unsafe {
let bytes = str_lit.get().len();
let llbytes = C_uint(bcx.ccx(), bytes);
let llcstr = C_cstr(bcx.ccx(), str_lit, false);
let llcstr = llvm::LLVMConstPointerCast(llcstr, Type::i8p(bcx.ccx()).to_ref());
Store(bcx, llcstr, GEPi(bcx, lldest, [0u, abi::slice_elt_base]));
Store(bcx, llbytes, GEPi(bcx, lldest, [0u, abi::slice_elt_len]));
bcx
}
}
}
}
pub fn write_content<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
vt: &VecTypes,
vstore_expr: &ast::Expr,
content_expr: &ast::Expr,
dest: Dest)
-> Block<'blk, 'tcx> {
let _icx = push_ctxt("tvec::write_content");
let fcx = bcx.fcx;
let mut bcx = bcx;
debug!("write_content(vt={}, dest={}, vstore_expr={})",
vt.to_string(bcx.ccx()),
dest.to_string(bcx.ccx()),
bcx.expr_to_string(vstore_expr));
match content_expr.node {
ast::ExprLit(ref lit) => {
match lit.node {
ast::LitStr(ref s, _) => {
match dest {
Ignore => return bcx,
SaveIn(lldest) => {
let bytes = s.get().len();
let llbytes = C_uint(bcx.ccx(), bytes);
let llcstr = C_cstr(bcx.ccx(), (*s).clone(), false);
base::call_memcpy(bcx,
lldest,
llcstr,
llbytes,
1);
return bcx;
}
}
}
_ => {
bcx.tcx().sess.span_bug(content_expr.span,
"unexpected evec content");
}
}
}
ast::ExprVec(ref elements) => {
match dest {
Ignore => {
for element in elements.iter() {
bcx = expr::trans_into(bcx, &**element, Ignore);
}
}
SaveIn(lldest) => {
let temp_scope = fcx.push_custom_cleanup_scope();
for (i, element) in elements.iter().enumerate() {
let lleltptr = GEPi(bcx, lldest, [i]);
debug!("writing index {} with lleltptr={}",
i, bcx.val_to_string(lleltptr));
bcx = expr::trans_into(bcx, &**element,
SaveIn(lleltptr));
let scope = cleanup::CustomScope(temp_scope);
fcx.schedule_lifetime_end(scope, lleltptr);
fcx.schedule_drop_mem(scope, lleltptr, vt.unit_ty);
}
fcx.pop_custom_cleanup_scope(temp_scope);
}
}
return bcx;
}
ast::ExprRepeat(ref element, ref count_expr) => {
match dest {
Ignore => {
return expr::trans_into(bcx, &**element, Ignore);
}
SaveIn(lldest) => {
match ty::eval_repeat_count(bcx.tcx(), &**count_expr) {
0 => bcx,
1 => expr::trans_into(bcx, &**element, SaveIn(lldest)),
count => {
let elem = unpack_datum!(bcx, expr::trans(bcx, &**element));
assert!(!ty::type_moves_by_default(bcx.tcx(), elem.ty));
let bcx = iter_vec_loop(bcx, lldest, vt,
C_uint(bcx.ccx(), count),
|set_bcx, lleltptr, _| {
elem.shallow_copy(set_bcx, lleltptr)
});
elem.add_clean_if_rvalue(bcx, element.id);
bcx
}
}
}
}
}
_ => {
bcx.tcx().sess.span_bug(content_expr.span,
"unexpected vec content");
}
}
}
pub fn vec_types_from_expr(bcx: Block, vec_expr: &ast::Expr) -> VecTypes {
let vec_ty = node_id_type(bcx, vec_expr.id);
vec_types(bcx, ty::sequence_element_type(bcx.tcx(), vec_ty))
}
pub fn vec_types(bcx: Block, unit_ty: ty::t) -> VecTypes {
let ccx = bcx.ccx();
let llunit_ty = type_of::type_of(ccx, unit_ty);
let llunit_size = nonzero_llsize_of(ccx, llunit_ty);
let llunit_alloc_size = llsize_of_alloc(ccx, llunit_ty);
VecTypes {
unit_ty: unit_ty,
llunit_ty: llunit_ty,
llunit_size: llunit_size,
llunit_alloc_size: llunit_alloc_size
}
}
pub fn elements_required(bcx: Block, content_expr: &ast::Expr) -> uint {
//! Figure out the number of elements we need to store this content
match content_expr.node {
ast::ExprLit(ref lit) => {
match lit.node {
ast::LitStr(ref s, _) => s.get().len(),
_ => {
bcx.tcx().sess.span_bug(content_expr.span,
"unexpected evec content")
}
}
},
ast::ExprVec(ref es) => es.len(),
ast::ExprRepeat(_, ref count_expr) => {
ty::eval_repeat_count(bcx.tcx(), &**count_expr)
}
_ => bcx.tcx().sess.span_bug(content_expr.span,
"unexpected vec content")
}
}
pub fn get_fixed_base_and_len(bcx: Block,
llval: ValueRef,
vec_length: uint)
-> (ValueRef, ValueRef) {
/*!
* Converts a fixed-length vector into the slice pair.
* The vector should be stored in `llval` which should be by ref.
*/
let ccx = bcx.ccx();
let base = expr::get_dataptr(bcx, llval);
let len = C_uint(ccx, vec_length);
(base, len)
}
fn get_slice_base_and_len(bcx: Block,
llval: ValueRef)
-> (ValueRef, ValueRef) {
let base = Load(bcx, GEPi(bcx, llval, [0u, abi::slice_elt_base]));
let len = Load(bcx, GEPi(bcx, llval, [0u, abi::slice_elt_len]));
(base, len)
}
pub fn get_base_and_len(bcx: Block,
llval: ValueRef,
vec_ty: ty::t)
-> (ValueRef, ValueRef) {
/*!
* Converts a vector into the slice pair. The vector should be
* stored in `llval` which should be by-reference. If you have a
* datum, you would probably prefer to call
* `Datum::get_base_and_len()` which will handle any conversions
* for you.
*/
let ccx = bcx.ccx();
match ty::get(vec_ty).sty {
ty::ty_vec(_, Some(n)) => get_fixed_base_and_len(bcx, llval, n),
ty::ty_open(ty) => match ty::get(ty).sty {
ty::ty_vec(_, None) | ty::ty_str => get_slice_base_and_len(bcx, llval),
_ => ccx.sess().bug("unexpected type in get_base_and_len")
},
// Only used for pattern matching.
ty::ty_uniq(ty) | ty::ty_rptr(_, ty::mt{ty, ..}) => match ty::get(ty).sty {
ty::ty_vec(_, None) | ty::ty_str => get_slice_base_and_len(bcx, llval),
ty::ty_vec(_, Some(n)) => {
let base = GEPi(bcx, Load(bcx, llval), [0u, 0u]);
(base, C_uint(ccx, n))
}
_ => ccx.sess().bug("unexpected type in get_base_and_len"),
},
_ => ccx.sess().bug("unexpected type in get_base_and_len"),
}
}
pub type iter_vec_block<'a, 'blk, 'tcx> =
|Block<'blk, 'tcx>, ValueRef, ty::t|: 'a -> Block<'blk, 'tcx>;
pub fn iter_vec_loop<'a, 'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
data_ptr: ValueRef,
vt: &VecTypes,
count: ValueRef,
f: iter_vec_block<'a, 'blk, 'tcx>)
-> Block<'blk, 'tcx> {
let _icx = push_ctxt("tvec::iter_vec_loop");
let fcx = bcx.fcx;
let next_bcx = fcx.new_temp_block("expr_repeat: while next");
let loop_bcx = fcx.new_temp_block("expr_repeat");
let cond_bcx = fcx.new_temp_block("expr_repeat: loop cond");
let body_bcx = fcx.new_temp_block("expr_repeat: body: set");
let inc_bcx = fcx.new_temp_block("expr_repeat: body: inc");
Br(bcx, loop_bcx.llbb);
let loop_counter = {
// i = 0
let i = alloca(loop_bcx, bcx.ccx().int_type(), "__i");
Store(loop_bcx, C_uint(bcx.ccx(), 0u), i);
Br(loop_bcx, cond_bcx.llbb);
i
};
{ // i < count
let lhs = Load(cond_bcx, loop_counter);
let rhs = count;
let cond_val = ICmp(cond_bcx, llvm::IntULT, lhs, rhs);
CondBr(cond_bcx, cond_val, body_bcx.llbb, next_bcx.llbb);
}
{ // loop body
let i = Load(body_bcx, loop_counter);
let lleltptr = if vt.llunit_alloc_size == 0 {
data_ptr
} else {
InBoundsGEP(body_bcx, data_ptr, [i])
};
let body_bcx = f(body_bcx, lleltptr, vt.unit_ty);
Br(body_bcx, inc_bcx.llbb);
}
{ // i += 1
let i = Load(inc_bcx, loop_counter);
let plusone = Add(inc_bcx, i, C_uint(bcx.ccx(), 1u));
Store(inc_bcx, plusone, loop_counter);
Br(inc_bcx, cond_bcx.llbb);
}
next_bcx
}
pub fn iter_vec_raw<'a, 'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
data_ptr: ValueRef,
unit_ty: ty::t,
len: ValueRef,
f: iter_vec_block<'a, 'blk, 'tcx>)
-> Block<'blk, 'tcx> {
let _icx = push_ctxt("tvec::iter_vec_raw");
let fcx = bcx.fcx;
let vt = vec_types(bcx, unit_ty);
let fill = Mul(bcx, len, vt.llunit_size);
if vt.llunit_alloc_size == 0 {
// Special-case vectors with elements of size 0 so they don't go out of bounds (#9890)
iter_vec_loop(bcx, data_ptr, &vt, fill, f)
} else {
// Calculate the last pointer address we want to handle.
// FIXME (#3729): Optimize this when the size of the unit type is
// statically known to not use pointer casts, which tend to confuse
// LLVM.
let data_end_ptr = pointer_add_byte(bcx, data_ptr, fill);
// Now perform the iteration.
let header_bcx = fcx.new_temp_block("iter_vec_loop_header");
Br(bcx, header_bcx.llbb);
let data_ptr =
Phi(header_bcx, val_ty(data_ptr), [data_ptr], [bcx.llbb]);
let not_yet_at_end =
ICmp(header_bcx, llvm::IntULT, data_ptr, data_end_ptr);
let body_bcx = fcx.new_temp_block("iter_vec_loop_body");
let next_bcx = fcx.new_temp_block("iter_vec_next");
CondBr(header_bcx, not_yet_at_end, body_bcx.llbb, next_bcx.llbb);
let body_bcx = f(body_bcx, data_ptr, vt.unit_ty);
AddIncomingToPhi(data_ptr, InBoundsGEP(body_bcx, data_ptr,
[C_int(bcx.ccx(), 1i)]),
body_bcx.llbb);
Br(body_bcx, header_bcx.llbb);
next_bcx
}
}