rust/src/librustc_trans/trans/tvec.rs
2015-02-18 15:27:42 -08:00

486 lines
18 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 trans::base::*;
use trans::base;
use trans::build::*;
use trans::cleanup;
use trans::cleanup::CleanupMethods;
use trans::common::*;
use trans::consts;
use trans::datum::*;
use trans::debuginfo::DebugLoc;
use trans::expr::{Dest, Ignore, SaveIn};
use trans::expr;
use trans::glue;
use trans::machine;
use trans::machine::llsize_of_alloc;
use trans::type_::Type;
use trans::type_of;
use middle::ty::{self, 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 make_drop_glue_unboxed<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
vptr: ValueRef,
unit_ty: Ty<'tcx>,
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 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, DebugLoc::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, 0_u32),
DebugLoc::None);
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, DebugLoc::None);
glue::trans_exchange_free_dyn(bcx,
dataptr,
size,
llalign,
DebugLoc::None)
})
} else {
bcx
}
} else {
bcx
}
})
}
#[derive(Copy)]
pub struct VecTypes<'tcx> {
pub unit_ty: Ty<'tcx>,
pub llunit_ty: Type,
pub llunit_alloc_size: u64
}
impl<'tcx> VecTypes<'tcx> {
pub fn to_string<'a>(&self, ccx: &CrateContext<'a, 'tcx>) -> String {
format!("VecTypes {{unit_ty={}, llunit_ty={}, llunit_alloc_size={}}}",
ty_to_string(ccx.tcx(), self.unit_ty),
ccx.tn().type_to_string(self.llunit_ty),
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))
}
};
}
/// &[...] 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).
pub fn trans_slice_vec<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
slice_expr: &ast::Expr,
content_expr: &ast::Expr)
-> DatumBlock<'blk, 'tcx, Expr> {
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):
if let ast::ExprLit(ref lit) = content_expr.node {
if let ast::LitStr(ref s, _) = lit.node {
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 fixed_ty = ty::mk_vec(bcx.tcx(),
vt.unit_ty,
Some(count));
let llfixed_ty = type_of::type_of(bcx.ccx(), fixed_ty);
// Always create an alloca even if zero-sized, to preserve
// the non-null invariant of the inner slice ptr
let llfixed = base::alloca(bcx, llfixed_ty, "");
if count > 0 {
// Arrange for the backing array to be cleaned up.
let cleanup_scope = cleanup::temporary_scope(bcx.tcx(), content_expr.id);
fcx.schedule_lifetime_end(cleanup_scope, llfixed);
fcx.schedule_drop_mem(cleanup_scope, llfixed, fixed_ty);
// Generate the content into the backing array.
// llfixed has type *[T x N], but we want the type *T,
// so use GEP to convert
bcx = write_content(bcx, &vt, slice_expr, content_expr,
SaveIn(GEPi(bcx, llfixed, &[0, 0])));
};
immediate_rvalue_bcx(bcx, llfixed, vec_ty).to_expr_datumblock()
}
/// 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.
pub fn trans_lit_str<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
lit_expr: &ast::Expr,
str_lit: InternedString,
dest: Dest)
-> Block<'blk, 'tcx> {
debug!("trans_lit_str(lit_expr={}, dest={})",
bcx.expr_to_string(lit_expr),
dest.to_string(bcx.ccx()));
match dest {
Ignore => bcx,
SaveIn(lldest) => {
let bytes = str_lit.len();
let llbytes = C_uint(bcx.ccx(), bytes);
let llcstr = C_cstr(bcx.ccx(), str_lit, false);
let llcstr = consts::ptrcast(llcstr, Type::i8p(bcx.ccx()));
Store(bcx, llcstr, GEPi(bcx, lldest, &[0, abi::FAT_PTR_ADDR]));
Store(bcx, llbytes, GEPi(bcx, lldest, &[0, abi::FAT_PTR_EXTRA]));
bcx
}
}
}
pub fn write_content<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
vt: &VecTypes<'tcx>,
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.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 {
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));
let bcx = iter_vec_loop(bcx, lldest, vt,
C_uint(bcx.ccx(), count),
|set_bcx, lleltptr, _| {
elem.shallow_copy(set_bcx, lleltptr)
});
bcx
}
}
}
}
}
_ => {
bcx.tcx().sess.span_bug(content_expr.span,
"unexpected vec content");
}
}
}
pub fn vec_types_from_expr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
vec_expr: &ast::Expr)
-> VecTypes<'tcx> {
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<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
unit_ty: Ty<'tcx>)
-> VecTypes<'tcx> {
let ccx = bcx.ccx();
let llunit_ty = type_of::type_of(ccx, unit_ty);
let llunit_alloc_size = llsize_of_alloc(ccx, llunit_ty);
VecTypes {
unit_ty: unit_ty,
llunit_ty: llunit_ty,
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.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")
}
}
/// Converts a fixed-length vector into the slice pair. The vector should be stored in `llval`
/// which should be by ref.
pub fn get_fixed_base_and_len(bcx: Block,
llval: ValueRef,
vec_length: uint)
-> (ValueRef, ValueRef) {
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, &[0, abi::FAT_PTR_ADDR]));
let len = Load(bcx, GEPi(bcx, llval, &[0, abi::FAT_PTR_EXTRA]));
(base, len)
}
/// 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.
pub fn get_base_and_len(bcx: Block,
llval: ValueRef,
vec_ty: Ty)
-> (ValueRef, ValueRef) {
let ccx = bcx.ccx();
match vec_ty.sty {
ty::ty_vec(_, Some(n)) => get_fixed_base_and_len(bcx, llval, n),
ty::ty_open(ty) => match 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.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), &[0, 0]);
(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 fn iter_vec_loop<'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>,
data_ptr: ValueRef,
vt: &VecTypes<'tcx>,
count: ValueRef,
f: F)
-> Block<'blk, 'tcx> where
F: FnOnce(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>,
{
let _icx = push_ctxt("tvec::iter_vec_loop");
let fcx = bcx.fcx;
let loop_bcx = fcx.new_temp_block("expr_repeat");
let next_bcx = fcx.new_temp_block("expr_repeat: next");
Br(bcx, loop_bcx.llbb, DebugLoc::None);
let loop_counter = Phi(loop_bcx, bcx.ccx().int_type(),
&[C_uint(bcx.ccx(), 0 as usize)], &[bcx.llbb]);
let bcx = loop_bcx;
let lleltptr = if vt.llunit_alloc_size == 0 {
data_ptr
} else {
InBoundsGEP(bcx, data_ptr, &[loop_counter])
};
let bcx = f(bcx, lleltptr, vt.unit_ty);
let plusone = Add(bcx, loop_counter, C_uint(bcx.ccx(), 1us), DebugLoc::None);
AddIncomingToPhi(loop_counter, plusone, bcx.llbb);
let cond_val = ICmp(bcx, llvm::IntULT, plusone, count, DebugLoc::None);
CondBr(bcx, cond_val, loop_bcx.llbb, next_bcx.llbb, DebugLoc::None);
next_bcx
}
pub fn iter_vec_raw<'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>,
data_ptr: ValueRef,
unit_ty: Ty<'tcx>,
len: ValueRef,
f: F)
-> Block<'blk, 'tcx> where
F: FnOnce(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>,
{
let _icx = push_ctxt("tvec::iter_vec_raw");
let fcx = bcx.fcx;
let vt = vec_types(bcx, unit_ty);
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, len, f)
} else {
// Calculate the last pointer address we want to handle.
let data_end_ptr = InBoundsGEP(bcx, data_ptr, &[len]);
// Now perform the iteration.
let header_bcx = fcx.new_temp_block("iter_vec_loop_header");
Br(bcx, header_bcx.llbb, DebugLoc::None);
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, DebugLoc::None);
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, DebugLoc::None);
let body_bcx = f(body_bcx, data_ptr, vt.unit_ty);
AddIncomingToPhi(data_ptr, InBoundsGEP(body_bcx, data_ptr,
&[C_int(bcx.ccx(), 1)]),
body_bcx.llbb);
Br(body_bcx, header_bcx.llbb, DebugLoc::None);
next_bcx
}
}