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fuchsia / third_party / rust / 545a3a94fcbdd68c4eeb60848c8eae2118c639c7 / . / src / librustc_trans / base.rs
blob: 1077cb296c1ac307e2e5a07535ed1eaf11166825 [file] [log] [blame]
// Copyright 2012-2015 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.
//! Translate the completed AST to the LLVM IR.
//!
//! Some functions here, such as trans_block and trans_expr, return a value --
//! the result of the translation to LLVM -- while others, such as trans_fn
//! and trans_item, are called only for the side effect of adding a
//! particular definition to the LLVM IR output we're producing.
//!
//! Hopefully useful general knowledge about trans:
//!
//! * There's no way to find out the Ty type of a ValueRef. Doing so
//! would be "trying to get the eggs out of an omelette" (credit:
//! pcwalton). You can, instead, find out its TypeRef by calling val_ty,
//! but one TypeRef corresponds to many `Ty`s; for instance, tup(int, int,
//! int) and rec(x=int, y=int, z=int) will have the same TypeRef.
#![allow(non_camel_case_types)]
use super::CrateTranslation;
use super::ModuleLlvm;
use super::ModuleSource;
use super::ModuleTranslation;
use assert_module_sources;
use back::link;
use back::linker::LinkerInfo;
use llvm::{BasicBlockRef, Linkage, ValueRef, Vector, get_param};
use llvm;
use rustc::cfg;
use rustc::hir::def_id::DefId;
use middle::lang_items::{LangItem, ExchangeMallocFnLangItem, StartFnLangItem};
use rustc::hir::pat_util::simple_name;
use rustc::ty::subst::{self, Substs};
use rustc::traits;
use rustc::ty::{self, Ty, TyCtxt, TypeFoldable};
use rustc::ty::adjustment::CustomCoerceUnsized;
use rustc::dep_graph::{DepNode, WorkProduct};
use rustc::hir::map as hir_map;
use rustc::util::common::time;
use rustc::mir::mir_map::MirMap;
use rustc_data_structures::graph::OUTGOING;
use session::config::{self, NoDebugInfo, FullDebugInfo};
use session::Session;
use _match;
use abi::{self, Abi, FnType};
use adt;
use attributes;
use build::*;
use builder::{Builder, noname};
use callee::{Callee, CallArgs, ArgExprs, ArgVals};
use cleanup::{self, CleanupMethods, DropHint};
use closure;
use common::{Block, C_bool, C_bytes_in_context, C_i32, C_int, C_uint, C_integral};
use collector::{self, TransItemCollectionMode};
use common::{C_null, C_struct_in_context, C_u64, C_u8, C_undef};
use common::{CrateContext, DropFlagHintsMap, Field, FunctionContext};
use common::{Result, NodeIdAndSpan, VariantInfo};
use common::{node_id_type, fulfill_obligation};
use common::{type_is_immediate, type_is_zero_size, val_ty};
use common;
use consts;
use context::{SharedCrateContext, CrateContextList};
use controlflow;
use datum;
use debuginfo::{self, DebugLoc, ToDebugLoc};
use declare;
use expr;
use glue;
use inline;
use machine;
use machine::{llalign_of_min, llsize_of};
use meth;
use mir;
use monomorphize::{self, Instance};
use partitioning::{self, PartitioningStrategy, CodegenUnit};
use symbol_map::SymbolMap;
use symbol_names_test;
use trans_item::TransItem;
use tvec;
use type_::Type;
use type_of;
use value::Value;
use Disr;
use util::common::indenter;
use util::sha2::Sha256;
use util::nodemap::{NodeMap, NodeSet, FnvHashSet};
use arena::TypedArena;
use libc::c_uint;
use std::ffi::{CStr, CString};
use std::borrow::Cow;
use std::cell::{Cell, RefCell};
use std::collections::HashMap;
use std::ptr;
use std::rc::Rc;
use std::str;
use std::{i8, i16, i32, i64};
use syntax_pos::{Span, DUMMY_SP};
use syntax::parse::token::InternedString;
use syntax::attr::AttrMetaMethods;
use syntax::attr;
use rustc::hir::intravisit::{self, Visitor};
use rustc::hir;
use syntax::ast;
thread_local! {
static TASK_LOCAL_INSN_KEY: RefCell<Option<Vec<&'static str>>> = {
RefCell::new(None)
}
}
pub fn with_insn_ctxt<F>(blk: F)
where F: FnOnce(&[&'static str])
{
TASK_LOCAL_INSN_KEY.with(move |slot| {
slot.borrow().as_ref().map(move |s| blk(s));
})
}
pub fn init_insn_ctxt() {
TASK_LOCAL_INSN_KEY.with(|slot| {
*slot.borrow_mut() = Some(Vec::new());
});
}
pub struct _InsnCtxt {
_cannot_construct_outside_of_this_module: (),
}
impl Drop for _InsnCtxt {
fn drop(&mut self) {
TASK_LOCAL_INSN_KEY.with(|slot| {
if let Some(ctx) = slot.borrow_mut().as_mut() {
ctx.pop();
}
})
}
}
pub fn push_ctxt(s: &'static str) -> _InsnCtxt {
debug!("new InsnCtxt: {}", s);
TASK_LOCAL_INSN_KEY.with(|slot| {
if let Some(ctx) = slot.borrow_mut().as_mut() {
ctx.push(s)
}
});
_InsnCtxt {
_cannot_construct_outside_of_this_module: (),
}
}
pub struct StatRecorder<'a, 'tcx: 'a> {
ccx: &'a CrateContext<'a, 'tcx>,
name: Option<String>,
istart: usize,
}
impl<'a, 'tcx> StatRecorder<'a, 'tcx> {
pub fn new(ccx: &'a CrateContext<'a, 'tcx>, name: String) -> StatRecorder<'a, 'tcx> {
let istart = ccx.stats().n_llvm_insns.get();
StatRecorder {
ccx: ccx,
name: Some(name),
istart: istart,
}
}
}
impl<'a, 'tcx> Drop for StatRecorder<'a, 'tcx> {
fn drop(&mut self) {
if self.ccx.sess().trans_stats() {
let iend = self.ccx.stats().n_llvm_insns.get();
self.ccx
.stats()
.fn_stats
.borrow_mut()
.push((self.name.take().unwrap(), iend - self.istart));
self.ccx.stats().n_fns.set(self.ccx.stats().n_fns.get() + 1);
// Reset LLVM insn count to avoid compound costs.
self.ccx.stats().n_llvm_insns.set(self.istart);
}
}
}
pub fn kind_for_closure(ccx: &CrateContext, closure_id: DefId) -> ty::ClosureKind {
*ccx.tcx().tables.borrow().closure_kinds.get(&closure_id).unwrap()
}
fn require_alloc_fn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, info_ty: Ty<'tcx>, it: LangItem) -> DefId {
match bcx.tcx().lang_items.require(it) {
Ok(id) => id,
Err(s) => {
bcx.sess().fatal(&format!("allocation of `{}` {}", info_ty, s));
}
}
}
// The following malloc_raw_dyn* functions allocate a box to contain
// a given type, but with a potentially dynamic size.
pub fn malloc_raw_dyn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
llty_ptr: Type,
info_ty: Ty<'tcx>,
size: ValueRef,
align: ValueRef,
debug_loc: DebugLoc)
-> Result<'blk, 'tcx> {
let _icx = push_ctxt("malloc_raw_exchange");
// Allocate space:
let def_id = require_alloc_fn(bcx, info_ty, ExchangeMallocFnLangItem);
let r = Callee::def(bcx.ccx(), def_id, bcx.tcx().mk_substs(Substs::empty()))
.call(bcx, debug_loc, ArgVals(&[size, align]), None);
Result::new(r.bcx, PointerCast(r.bcx, r.val, llty_ptr))
}
pub fn bin_op_to_icmp_predicate(op: hir::BinOp_,
signed: bool)
-> llvm::IntPredicate {
match op {
hir::BiEq => llvm::IntEQ,
hir::BiNe => llvm::IntNE,
hir::BiLt => if signed { llvm::IntSLT } else { llvm::IntULT },
hir::BiLe => if signed { llvm::IntSLE } else { llvm::IntULE },
hir::BiGt => if signed { llvm::IntSGT } else { llvm::IntUGT },
hir::BiGe => if signed { llvm::IntSGE } else { llvm::IntUGE },
op => {
bug!("comparison_op_to_icmp_predicate: expected comparison operator, \
found {:?}",
op)
}
}
}
pub fn bin_op_to_fcmp_predicate(op: hir::BinOp_) -> llvm::RealPredicate {
match op {
hir::BiEq => llvm::RealOEQ,
hir::BiNe => llvm::RealUNE,
hir::BiLt => llvm::RealOLT,
hir::BiLe => llvm::RealOLE,
hir::BiGt => llvm::RealOGT,
hir::BiGe => llvm::RealOGE,
op => {
bug!("comparison_op_to_fcmp_predicate: expected comparison operator, \
found {:?}",
op);
}
}
}
pub fn compare_fat_ptrs<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
lhs_addr: ValueRef,
lhs_extra: ValueRef,
rhs_addr: ValueRef,
rhs_extra: ValueRef,
_t: Ty<'tcx>,
op: hir::BinOp_,
debug_loc: DebugLoc)
-> ValueRef {
match op {
hir::BiEq => {
let addr_eq = ICmp(bcx, llvm::IntEQ, lhs_addr, rhs_addr, debug_loc);
let extra_eq = ICmp(bcx, llvm::IntEQ, lhs_extra, rhs_extra, debug_loc);
And(bcx, addr_eq, extra_eq, debug_loc)
}
hir::BiNe => {
let addr_eq = ICmp(bcx, llvm::IntNE, lhs_addr, rhs_addr, debug_loc);
let extra_eq = ICmp(bcx, llvm::IntNE, lhs_extra, rhs_extra, debug_loc);
Or(bcx, addr_eq, extra_eq, debug_loc)
}
hir::BiLe | hir::BiLt | hir::BiGe | hir::BiGt => {
// a OP b ~ a.0 STRICT(OP) b.0 | (a.0 == b.0 && a.1 OP a.1)
let (op, strict_op) = match op {
hir::BiLt => (llvm::IntULT, llvm::IntULT),
hir::BiLe => (llvm::IntULE, llvm::IntULT),
hir::BiGt => (llvm::IntUGT, llvm::IntUGT),
hir::BiGe => (llvm::IntUGE, llvm::IntUGT),
_ => bug!(),
};
let addr_eq = ICmp(bcx, llvm::IntEQ, lhs_addr, rhs_addr, debug_loc);
let extra_op = ICmp(bcx, op, lhs_extra, rhs_extra, debug_loc);
let addr_eq_extra_op = And(bcx, addr_eq, extra_op, debug_loc);
let addr_strict = ICmp(bcx, strict_op, lhs_addr, rhs_addr, debug_loc);
Or(bcx, addr_strict, addr_eq_extra_op, debug_loc)
}
_ => {
bug!("unexpected fat ptr binop");
}
}
}
pub fn compare_scalar_types<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
lhs: ValueRef,
rhs: ValueRef,
t: Ty<'tcx>,
op: hir::BinOp_,
debug_loc: DebugLoc)
-> ValueRef {
match t.sty {
ty::TyTuple(ref tys) if tys.is_empty() => {
// We don't need to do actual comparisons for nil.
// () == () holds but () < () does not.
match op {
hir::BiEq | hir::BiLe | hir::BiGe => return C_bool(bcx.ccx(), true),
hir::BiNe | hir::BiLt | hir::BiGt => return C_bool(bcx.ccx(), false),
// refinements would be nice
_ => bug!("compare_scalar_types: must be a comparison operator"),
}
}
ty::TyFnDef(..) | ty::TyFnPtr(_) | ty::TyBool | ty::TyUint(_) | ty::TyChar => {
ICmp(bcx,
bin_op_to_icmp_predicate(op, false),
lhs,
rhs,
debug_loc)
}
ty::TyRawPtr(mt) if common::type_is_sized(bcx.tcx(), mt.ty) => {
ICmp(bcx,
bin_op_to_icmp_predicate(op, false),
lhs,
rhs,
debug_loc)
}
ty::TyRawPtr(_) => {
let lhs_addr = Load(bcx, GEPi(bcx, lhs, &[0, abi::FAT_PTR_ADDR]));
let lhs_extra = Load(bcx, GEPi(bcx, lhs, &[0, abi::FAT_PTR_EXTRA]));
let rhs_addr = Load(bcx, GEPi(bcx, rhs, &[0, abi::FAT_PTR_ADDR]));
let rhs_extra = Load(bcx, GEPi(bcx, rhs, &[0, abi::FAT_PTR_EXTRA]));
compare_fat_ptrs(bcx,
lhs_addr,
lhs_extra,
rhs_addr,
rhs_extra,
t,
op,
debug_loc)
}
ty::TyInt(_) => {
ICmp(bcx,
bin_op_to_icmp_predicate(op, true),
lhs,
rhs,
debug_loc)
}
ty::TyFloat(_) => {
FCmp(bcx,
bin_op_to_fcmp_predicate(op),
lhs,
rhs,
debug_loc)
}
// Should never get here, because t is scalar.
_ => bug!("non-scalar type passed to compare_scalar_types"),
}
}
pub fn compare_simd_types<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
lhs: ValueRef,
rhs: ValueRef,
t: Ty<'tcx>,
ret_ty: Type,
op: hir::BinOp_,
debug_loc: DebugLoc)
-> ValueRef {
let signed = match t.sty {
ty::TyFloat(_) => {
let cmp = bin_op_to_fcmp_predicate(op);
return SExt(bcx, FCmp(bcx, cmp, lhs, rhs, debug_loc), ret_ty);
},
ty::TyUint(_) => false,
ty::TyInt(_) => true,
_ => bug!("compare_simd_types: invalid SIMD type"),
};
let cmp = bin_op_to_icmp_predicate(op, signed);
// LLVM outputs an `< size x i1 >`, so we need to perform a sign extension
// to get the correctly sized type. This will compile to a single instruction
// once the IR is converted to assembly if the SIMD instruction is supported
// by the target architecture.
SExt(bcx, ICmp(bcx, cmp, lhs, rhs, debug_loc), ret_ty)
}
// Iterates through the elements of a structural type.
pub fn iter_structural_ty<'blk, 'tcx, F>(cx: Block<'blk, 'tcx>,
av: ValueRef,
t: Ty<'tcx>,
mut f: F)
-> Block<'blk, 'tcx>
where F: FnMut(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>
{
let _icx = push_ctxt("iter_structural_ty");
fn iter_variant<'blk, 'tcx, F>(cx: Block<'blk, 'tcx>,
repr: &adt::Repr<'tcx>,
av: adt::MaybeSizedValue,
variant: ty::VariantDef<'tcx>,
substs: &Substs<'tcx>,
f: &mut F)
-> Block<'blk, 'tcx>
where F: FnMut(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>
{
let _icx = push_ctxt("iter_variant");
let tcx = cx.tcx();
let mut cx = cx;
for (i, field) in variant.fields.iter().enumerate() {
let arg = monomorphize::field_ty(tcx, substs, field);
cx = f(cx,
adt::trans_field_ptr(cx, repr, av, Disr::from(variant.disr_val), i),
arg);
}
return cx;
}
let value = if common::type_is_sized(cx.tcx(), t) {
adt::MaybeSizedValue::sized(av)
} else {
let data = Load(cx, expr::get_dataptr(cx, av));
let info = Load(cx, expr::get_meta(cx, av));
adt::MaybeSizedValue::unsized_(data, info)
};
let mut cx = cx;
match t.sty {
ty::TyStruct(..) => {
let repr = adt::represent_type(cx.ccx(), t);
let VariantInfo { fields, discr } = VariantInfo::from_ty(cx.tcx(), t, None);
for (i, &Field(_, field_ty)) in fields.iter().enumerate() {
let llfld_a = adt::trans_field_ptr(cx, &repr, value, Disr::from(discr), i);
let val = if common::type_is_sized(cx.tcx(), field_ty) {
llfld_a
} else {
let scratch = datum::rvalue_scratch_datum(cx, field_ty, "__fat_ptr_iter");
Store(cx, llfld_a, expr::get_dataptr(cx, scratch.val));
Store(cx, value.meta, expr::get_meta(cx, scratch.val));
scratch.val
};
cx = f(cx, val, field_ty);
}
}
ty::TyClosure(_, ref substs) => {
let repr = adt::represent_type(cx.ccx(), t);
for (i, upvar_ty) in substs.upvar_tys.iter().enumerate() {
let llupvar = adt::trans_field_ptr(cx, &repr, value, Disr(0), i);
cx = f(cx, llupvar, upvar_ty);
}
}
ty::TyArray(_, n) => {
let (base, len) = tvec::get_fixed_base_and_len(cx, value.value, n);
let unit_ty = t.sequence_element_type(cx.tcx());
cx = tvec::iter_vec_raw(cx, base, unit_ty, len, f);
}
ty::TySlice(_) | ty::TyStr => {
let unit_ty = t.sequence_element_type(cx.tcx());
cx = tvec::iter_vec_raw(cx, value.value, unit_ty, value.meta, f);
}
ty::TyTuple(ref args) => {
let repr = adt::represent_type(cx.ccx(), t);
for (i, arg) in args.iter().enumerate() {
let llfld_a = adt::trans_field_ptr(cx, &repr, value, Disr(0), i);
cx = f(cx, llfld_a, *arg);
}
}
ty::TyEnum(en, substs) => {
let fcx = cx.fcx;
let ccx = fcx.ccx;
let repr = adt::represent_type(ccx, t);
let n_variants = en.variants.len();
// NB: we must hit the discriminant first so that structural
// comparison know not to proceed when the discriminants differ.
match adt::trans_switch(cx, &repr, av, false) {
(_match::Single, None) => {
if n_variants != 0 {
assert!(n_variants == 1);
cx = iter_variant(cx, &repr, adt::MaybeSizedValue::sized(av),
&en.variants[0], substs, &mut f);
}
}
(_match::Switch, Some(lldiscrim_a)) => {
cx = f(cx, lldiscrim_a, cx.tcx().types.isize);
// Create a fall-through basic block for the "else" case of
// the switch instruction we're about to generate. Note that
// we do **not** use an Unreachable instruction here, even
// though most of the time this basic block will never be hit.
//
// When an enum is dropped it's contents are currently
// overwritten to DTOR_DONE, which means the discriminant
// could have changed value to something not within the actual
// range of the discriminant. Currently this function is only
// used for drop glue so in this case we just return quickly
// from the outer function, and any other use case will only
// call this for an already-valid enum in which case the `ret
// void` will never be hit.
let ret_void_cx = fcx.new_temp_block("enum-iter-ret-void");
RetVoid(ret_void_cx, DebugLoc::None);
let llswitch = Switch(cx, lldiscrim_a, ret_void_cx.llbb, n_variants);
let next_cx = fcx.new_temp_block("enum-iter-next");
for variant in &en.variants {
let variant_cx = fcx.new_temp_block(&format!("enum-iter-variant-{}",
&variant.disr_val
.to_string()));
let case_val = adt::trans_case(cx, &repr, Disr::from(variant.disr_val));
AddCase(llswitch, case_val, variant_cx.llbb);
let variant_cx = iter_variant(variant_cx,
&repr,
value,
variant,
substs,
&mut f);
Br(variant_cx, next_cx.llbb, DebugLoc::None);
}
cx = next_cx;
}
_ => ccx.sess().unimpl("value from adt::trans_switch in iter_structural_ty"),
}
}
_ => {
cx.sess().unimpl(&format!("type in iter_structural_ty: {}", t))
}
}
return cx;
}
/// Retrieve the information we are losing (making dynamic) in an unsizing
/// adjustment.
///
/// The `old_info` argument is a bit funny. It is intended for use
/// in an upcast, where the new vtable for an object will be drived
/// from the old one.
pub fn unsized_info<'ccx, 'tcx>(ccx: &CrateContext<'ccx, 'tcx>,
source: Ty<'tcx>,
target: Ty<'tcx>,
old_info: Option<ValueRef>)
-> ValueRef {
let (source, target) = ccx.tcx().struct_lockstep_tails(source, target);
match (&source.sty, &target.sty) {
(&ty::TyArray(_, len), &ty::TySlice(_)) => C_uint(ccx, len),
(&ty::TyTrait(_), &ty::TyTrait(_)) => {
// For now, upcasts are limited to changes in marker
// traits, and hence never actually require an actual
// change to the vtable.
old_info.expect("unsized_info: missing old info for trait upcast")
}
(_, &ty::TyTrait(box ty::TraitTy { ref principal, .. })) => {
// Note that we preserve binding levels here:
let substs = principal.0.substs.with_self_ty(source).erase_regions();
let substs = ccx.tcx().mk_substs(substs);
let trait_ref = ty::Binder(ty::TraitRef {
def_id: principal.def_id(),
substs: substs,
});
consts::ptrcast(meth::get_vtable(ccx, trait_ref),
Type::vtable_ptr(ccx))
}
_ => bug!("unsized_info: invalid unsizing {:?} -> {:?}",
source,
target),
}
}
/// Coerce `src` to `dst_ty`. `src_ty` must be a thin pointer.
pub fn unsize_thin_ptr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
src: ValueRef,
src_ty: Ty<'tcx>,
dst_ty: Ty<'tcx>)
-> (ValueRef, ValueRef) {
debug!("unsize_thin_ptr: {:?} => {:?}", src_ty, dst_ty);
match (&src_ty.sty, &dst_ty.sty) {
(&ty::TyBox(a), &ty::TyBox(b)) |
(&ty::TyRef(_, ty::TypeAndMut { ty: a, .. }),
&ty::TyRef(_, ty::TypeAndMut { ty: b, .. })) |
(&ty::TyRef(_, ty::TypeAndMut { ty: a, .. }),
&ty::TyRawPtr(ty::TypeAndMut { ty: b, .. })) |
(&ty::TyRawPtr(ty::TypeAndMut { ty: a, .. }),
&ty::TyRawPtr(ty::TypeAndMut { ty: b, .. })) => {
assert!(common::type_is_sized(bcx.tcx(), a));
let ptr_ty = type_of::in_memory_type_of(bcx.ccx(), b).ptr_to();
(PointerCast(bcx, src, ptr_ty),
unsized_info(bcx.ccx(), a, b, None))
}
_ => bug!("unsize_thin_ptr: called on bad types"),
}
}
/// Coerce `src`, which is a reference to a value of type `src_ty`,
/// to a value of type `dst_ty` and store the result in `dst`
pub fn coerce_unsized_into<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
src: ValueRef,
src_ty: Ty<'tcx>,
dst: ValueRef,
dst_ty: Ty<'tcx>) {
match (&src_ty.sty, &dst_ty.sty) {
(&ty::TyBox(..), &ty::TyBox(..)) |
(&ty::TyRef(..), &ty::TyRef(..)) |
(&ty::TyRef(..), &ty::TyRawPtr(..)) |
(&ty::TyRawPtr(..), &ty::TyRawPtr(..)) => {
let (base, info) = if common::type_is_fat_ptr(bcx.tcx(), src_ty) {
// fat-ptr to fat-ptr unsize preserves the vtable
// i.e. &'a fmt::Debug+Send => &'a fmt::Debug
// So we need to pointercast the base to ensure
// the types match up.
let (base, info) = load_fat_ptr(bcx, src, src_ty);
let llcast_ty = type_of::fat_ptr_base_ty(bcx.ccx(), dst_ty);
let base = PointerCast(bcx, base, llcast_ty);
(base, info)
} else {
let base = load_ty(bcx, src, src_ty);
unsize_thin_ptr(bcx, base, src_ty, dst_ty)
};
store_fat_ptr(bcx, base, info, dst, dst_ty);
}
// This can be extended to enums and tuples in the future.
// (&ty::TyEnum(def_id_a, _), &ty::TyEnum(def_id_b, _)) |
(&ty::TyStruct(def_a, _), &ty::TyStruct(def_b, _)) => {
assert_eq!(def_a, def_b);
let src_repr = adt::represent_type(bcx.ccx(), src_ty);
let src_fields = match &*src_repr {
&adt::Repr::Univariant(ref s, _) => &s.fields,
_ => bug!("struct has non-univariant repr"),
};
let dst_repr = adt::represent_type(bcx.ccx(), dst_ty);
let dst_fields = match &*dst_repr {
&adt::Repr::Univariant(ref s, _) => &s.fields,
_ => bug!("struct has non-univariant repr"),
};
let src = adt::MaybeSizedValue::sized(src);
let dst = adt::MaybeSizedValue::sized(dst);
let iter = src_fields.iter().zip(dst_fields).enumerate();
for (i, (src_fty, dst_fty)) in iter {
if type_is_zero_size(bcx.ccx(), dst_fty) {
continue;
}
let src_f = adt::trans_field_ptr(bcx, &src_repr, src, Disr(0), i);
let dst_f = adt::trans_field_ptr(bcx, &dst_repr, dst, Disr(0), i);
if src_fty == dst_fty {
memcpy_ty(bcx, dst_f, src_f, src_fty);
} else {
coerce_unsized_into(bcx, src_f, src_fty, dst_f, dst_fty);
}
}
}
_ => bug!("coerce_unsized_into: invalid coercion {:?} -> {:?}",
src_ty,
dst_ty),
}
}
pub fn custom_coerce_unsize_info<'scx, 'tcx>(scx: &SharedCrateContext<'scx, 'tcx>,
source_ty: Ty<'tcx>,
target_ty: Ty<'tcx>)
-> CustomCoerceUnsized {
let trait_substs = Substs::new(subst::VecPerParamSpace::new(vec![target_ty],
vec![source_ty],
Vec::new()),
subst::VecPerParamSpace::empty());
let trait_ref = ty::Binder(ty::TraitRef {
def_id: scx.tcx().lang_items.coerce_unsized_trait().unwrap(),
substs: scx.tcx().mk_substs(trait_substs)
});
match fulfill_obligation(scx, DUMMY_SP, trait_ref) {
traits::VtableImpl(traits::VtableImplData { impl_def_id, .. }) => {
scx.tcx().custom_coerce_unsized_kind(impl_def_id)
}
vtable => {
bug!("invalid CoerceUnsized vtable: {:?}", vtable);
}
}
}
pub fn cast_shift_expr_rhs(cx: Block, op: hir::BinOp_, lhs: ValueRef, rhs: ValueRef) -> ValueRef {
cast_shift_rhs(op, lhs, rhs, |a, b| Trunc(cx, a, b), |a, b| ZExt(cx, a, b))
}
pub fn cast_shift_const_rhs(op: hir::BinOp_, lhs: ValueRef, rhs: ValueRef) -> ValueRef {
cast_shift_rhs(op,
lhs,
rhs,
|a, b| unsafe { llvm::LLVMConstTrunc(a, b.to_ref()) },
|a, b| unsafe { llvm::LLVMConstZExt(a, b.to_ref()) })
}
fn cast_shift_rhs<F, G>(op: hir::BinOp_,
lhs: ValueRef,
rhs: ValueRef,
trunc: F,
zext: G)
-> ValueRef
where F: FnOnce(ValueRef, Type) -> ValueRef,
G: FnOnce(ValueRef, Type) -> ValueRef
{
// Shifts may have any size int on the rhs
if op.is_shift() {
let mut rhs_llty = val_ty(rhs);
let mut lhs_llty = val_ty(lhs);
if rhs_llty.kind() == Vector {
rhs_llty = rhs_llty.element_type()
}
if lhs_llty.kind() == Vector {
lhs_llty = lhs_llty.element_type()
}
let rhs_sz = rhs_llty.int_width();
let lhs_sz = lhs_llty.int_width();
if lhs_sz < rhs_sz {
trunc(rhs, lhs_llty)
} else if lhs_sz > rhs_sz {
// FIXME (#1877: If shifting by negative
// values becomes not undefined then this is wrong.
zext(rhs, lhs_llty)
} else {
rhs
}
} else {
rhs
}
}
pub fn llty_and_min_for_signed_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
val_t: Ty<'tcx>)
-> (Type, u64) {
match val_t.sty {
ty::TyInt(t) => {
let llty = Type::int_from_ty(cx.ccx(), t);
let min = match t {
ast::IntTy::Is if llty == Type::i32(cx.ccx()) => i32::MIN as u64,
ast::IntTy::Is => i64::MIN as u64,
ast::IntTy::I8 => i8::MIN as u64,
ast::IntTy::I16 => i16::MIN as u64,
ast::IntTy::I32 => i32::MIN as u64,
ast::IntTy::I64 => i64::MIN as u64,
};
(llty, min)
}
_ => bug!(),
}
}
pub fn fail_if_zero_or_overflows<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
call_info: NodeIdAndSpan,
divrem: hir::BinOp,
lhs: ValueRef,
rhs: ValueRef,
rhs_t: Ty<'tcx>)
-> Block<'blk, 'tcx> {
use rustc_const_math::{ConstMathErr, Op};
let (zero_err, overflow_err) = if divrem.node == hir::BiDiv {
(ConstMathErr::DivisionByZero, ConstMathErr::Overflow(Op::Div))
} else {
(ConstMathErr::RemainderByZero, ConstMathErr::Overflow(Op::Rem))
};
let debug_loc = call_info.debug_loc();
let (is_zero, is_signed) = match rhs_t.sty {
ty::TyInt(t) => {
let zero = C_integral(Type::int_from_ty(cx.ccx(), t), 0, false);
(ICmp(cx, llvm::IntEQ, rhs, zero, debug_loc), true)
}
ty::TyUint(t) => {
let zero = C_integral(Type::uint_from_ty(cx.ccx(), t), 0, false);
(ICmp(cx, llvm::IntEQ, rhs, zero, debug_loc), false)
}
ty::TyStruct(def, _) if def.is_simd() => {
let mut res = C_bool(cx.ccx(), false);
for i in 0..rhs_t.simd_size(cx.tcx()) {
res = Or(cx,
res,
IsNull(cx, ExtractElement(cx, rhs, C_int(cx.ccx(), i as i64))),
debug_loc);
}
(res, false)
}
_ => {
bug!("fail-if-zero on unexpected type: {}", rhs_t);
}
};
let bcx = with_cond(cx, is_zero, |bcx| {
controlflow::trans_fail(bcx, call_info, InternedString::new(zero_err.description()))
});
// To quote LLVM's documentation for the sdiv instruction:
//
// Division by zero leads to undefined behavior. Overflow also leads
// to undefined behavior; this is a rare case, but can occur, for
// example, by doing a 32-bit division of -2147483648 by -1.
//
// In order to avoid undefined behavior, we perform runtime checks for
// signed division/remainder which would trigger overflow. For unsigned
// integers, no action beyond checking for zero need be taken.
if is_signed {
let (llty, min) = llty_and_min_for_signed_ty(cx, rhs_t);
let minus_one = ICmp(bcx,
llvm::IntEQ,
rhs,
C_integral(llty, !0, false),
debug_loc);
with_cond(bcx, minus_one, |bcx| {
let is_min = ICmp(bcx,
llvm::IntEQ,
lhs,
C_integral(llty, min, true),
debug_loc);
with_cond(bcx, is_min, |bcx| {
controlflow::trans_fail(bcx, call_info,
InternedString::new(overflow_err.description()))
})
})
} else {
bcx
}
}
pub fn invoke<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
llfn: ValueRef,
llargs: &[ValueRef],
debug_loc: DebugLoc)
-> (ValueRef, Block<'blk, 'tcx>) {
let _icx = push_ctxt("invoke_");
if bcx.unreachable.get() {
return (C_null(Type::i8(bcx.ccx())), bcx);
}
match bcx.opt_node_id {
None => {
debug!("invoke at ???");
}
Some(id) => {
debug!("invoke at {}", bcx.tcx().map.node_to_string(id));
}
}
if need_invoke(bcx) {
debug!("invoking {:?} at {:?}", Value(llfn), bcx.llbb);
for &llarg in llargs {
debug!("arg: {:?}", Value(llarg));
}
let normal_bcx = bcx.fcx.new_temp_block("normal-return");
let landing_pad = bcx.fcx.get_landing_pad();
let llresult = Invoke(bcx,
llfn,
&llargs[..],
normal_bcx.llbb,
landing_pad,
debug_loc);
return (llresult, normal_bcx);
} else {
debug!("calling {:?} at {:?}", Value(llfn), bcx.llbb);
for &llarg in llargs {
debug!("arg: {:?}", Value(llarg));
}
let llresult = Call(bcx, llfn, &llargs[..], debug_loc);
return (llresult, bcx);
}
}
/// Returns whether this session's target will use SEH-based unwinding.
///
/// This is only true for MSVC targets, and even then the 64-bit MSVC target
/// currently uses SEH-ish unwinding with DWARF info tables to the side (same as
/// 64-bit MinGW) instead of "full SEH".
pub fn wants_msvc_seh(sess: &Session) -> bool {
sess.target.target.options.is_like_msvc
}
pub fn avoid_invoke(bcx: Block) -> bool {
bcx.sess().no_landing_pads() || bcx.lpad().is_some()
}
pub fn need_invoke(bcx: Block) -> bool {
if avoid_invoke(bcx) {
false
} else {
bcx.fcx.needs_invoke()
}
}
pub fn load_if_immediate<'blk, 'tcx>(cx: Block<'blk, 'tcx>, v: ValueRef, t: Ty<'tcx>) -> ValueRef {
let _icx = push_ctxt("load_if_immediate");
if type_is_immediate(cx.ccx(), t) {
return load_ty(cx, v, t);
}
return v;
}
/// Helper for loading values from memory. Does the necessary conversion if the in-memory type
/// differs from the type used for SSA values. Also handles various special cases where the type
/// gives us better information about what we are loading.
pub fn load_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>, ptr: ValueRef, t: Ty<'tcx>) -> ValueRef {
if cx.unreachable.get() {
return C_undef(type_of::type_of(cx.ccx(), t));
}
load_ty_builder(&B(cx), ptr, t)
}
pub fn load_ty_builder<'a, 'tcx>(b: &Builder<'a, 'tcx>, ptr: ValueRef, t: Ty<'tcx>) -> ValueRef {
let ccx = b.ccx;
if type_is_zero_size(ccx, t) {
return C_undef(type_of::type_of(ccx, t));
}
unsafe {
let global = llvm::LLVMIsAGlobalVariable(ptr);
if !global.is_null() && llvm::LLVMIsGlobalConstant(global) == llvm::True {
let val = llvm::LLVMGetInitializer(global);
if !val.is_null() {
if t.is_bool() {
return llvm::LLVMConstTrunc(val, Type::i1(ccx).to_ref());
}
return val;
}
}
}
if t.is_bool() {
b.trunc(b.load_range_assert(ptr, 0, 2, llvm::False), Type::i1(ccx))
} else if t.is_char() {
// a char is a Unicode codepoint, and so takes values from 0
// to 0x10FFFF inclusive only.
b.load_range_assert(ptr, 0, 0x10FFFF + 1, llvm::False)
} else if (t.is_region_ptr() || t.is_unique()) &&
!common::type_is_fat_ptr(ccx.tcx(), t) {
b.load_nonnull(ptr)
} else {
b.load(ptr)
}
}
/// Helper for storing values in memory. Does the necessary conversion if the in-memory type
/// differs from the type used for SSA values.
pub fn store_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>, v: ValueRef, dst: ValueRef, t: Ty<'tcx>) {
if cx.unreachable.get() {
return;
}
debug!("store_ty: {:?} : {:?} <- {:?}", Value(dst), t, Value(v));
if common::type_is_fat_ptr(cx.tcx(), t) {
Store(cx,
ExtractValue(cx, v, abi::FAT_PTR_ADDR),
expr::get_dataptr(cx, dst));
Store(cx,
ExtractValue(cx, v, abi::FAT_PTR_EXTRA),
expr::get_meta(cx, dst));
} else {
Store(cx, from_immediate(cx, v), dst);
}
}
pub fn store_fat_ptr<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
data: ValueRef,
extra: ValueRef,
dst: ValueRef,
_ty: Ty<'tcx>) {
// FIXME: emit metadata
Store(cx, data, expr::get_dataptr(cx, dst));
Store(cx, extra, expr::get_meta(cx, dst));
}
pub fn load_fat_ptr<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
src: ValueRef,
_ty: Ty<'tcx>)
-> (ValueRef, ValueRef) {
// FIXME: emit metadata
(Load(cx, expr::get_dataptr(cx, src)),
Load(cx, expr::get_meta(cx, src)))
}
pub fn from_immediate(bcx: Block, val: ValueRef) -> ValueRef {
if val_ty(val) == Type::i1(bcx.ccx()) {
ZExt(bcx, val, Type::i8(bcx.ccx()))
} else {
val
}
}
pub fn to_immediate(bcx: Block, val: ValueRef, ty: Ty) -> ValueRef {
if ty.is_bool() {
Trunc(bcx, val, Type::i1(bcx.ccx()))
} else {
val
}
}
pub fn init_local<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, local: &hir::Local) -> Block<'blk, 'tcx> {
debug!("init_local(bcx={}, local.id={})", bcx.to_str(), local.id);
let _indenter = indenter();
let _icx = push_ctxt("init_local");
_match::store_local(bcx, local)
}
pub fn raw_block<'blk, 'tcx>(fcx: &'blk FunctionContext<'blk, 'tcx>,
llbb: BasicBlockRef)
-> Block<'blk, 'tcx> {
common::BlockS::new(llbb, None, fcx)
}
pub fn with_cond<'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>, val: ValueRef, f: F) -> Block<'blk, 'tcx>
where F: FnOnce(Block<'blk, 'tcx>) -> Block<'blk, 'tcx>
{
let _icx = push_ctxt("with_cond");
if bcx.unreachable.get() || common::const_to_opt_uint(val) == Some(0) {
return bcx;
}
let fcx = bcx.fcx;
let next_cx = fcx.new_temp_block("next");
let cond_cx = fcx.new_temp_block("cond");
CondBr(bcx, val, cond_cx.llbb, next_cx.llbb, DebugLoc::None);
let after_cx = f(cond_cx);
if !after_cx.terminated.get() {
Br(after_cx, next_cx.llbb, DebugLoc::None);
}
next_cx
}
pub enum Lifetime { Start, End }
// If LLVM lifetime intrinsic support is enabled (i.e. optimizations
// on), and `ptr` is nonzero-sized, then extracts the size of `ptr`
// and the intrinsic for `lt` and passes them to `emit`, which is in
// charge of generating code to call the passed intrinsic on whatever
// block of generated code is targetted for the intrinsic.
//
// If LLVM lifetime intrinsic support is disabled (i.e. optimizations
// off) or `ptr` is zero-sized, then no-op (does not call `emit`).
fn core_lifetime_emit<'blk, 'tcx, F>(ccx: &'blk CrateContext<'blk, 'tcx>,
ptr: ValueRef,
lt: Lifetime,
emit: F)
where F: FnOnce(&'blk CrateContext<'blk, 'tcx>, machine::llsize, ValueRef)
{
if ccx.sess().opts.optimize == config::OptLevel::No {
return;
}
let _icx = push_ctxt(match lt {
Lifetime::Start => "lifetime_start",
Lifetime::End => "lifetime_end"
});
let size = machine::llsize_of_alloc(ccx, val_ty(ptr).element_type());
if size == 0 {
return;
}
let lifetime_intrinsic = ccx.get_intrinsic(match lt {
Lifetime::Start => "llvm.lifetime.start",
Lifetime::End => "llvm.lifetime.end"
});
emit(ccx, size, lifetime_intrinsic)
}
impl Lifetime {
pub fn call(self, b: &Builder, ptr: ValueRef) {
core_lifetime_emit(b.ccx, ptr, self, |ccx, size, lifetime_intrinsic| {
let ptr = b.pointercast(ptr, Type::i8p(ccx));
b.call(lifetime_intrinsic, &[C_u64(ccx, size), ptr], None);
});
}
}
pub fn call_lifetime_start(bcx: Block, ptr: ValueRef) {
if !bcx.unreachable.get() {
Lifetime::Start.call(&bcx.build(), ptr);
}
}
pub fn call_lifetime_end(bcx: Block, ptr: ValueRef) {
if !bcx.unreachable.get() {
Lifetime::End.call(&bcx.build(), ptr);
}
}
// Generates code for resumption of unwind at the end of a landing pad.
pub fn trans_unwind_resume(bcx: Block, lpval: ValueRef) {
if !bcx.sess().target.target.options.custom_unwind_resume {
Resume(bcx, lpval);
} else {
let exc_ptr = ExtractValue(bcx, lpval, 0);
bcx.fcx.eh_unwind_resume()
.call(bcx, DebugLoc::None, ArgVals(&[exc_ptr]), None);
}
}
pub fn call_memcpy<'bcx, 'tcx>(b: &Builder<'bcx, 'tcx>,
dst: ValueRef,
src: ValueRef,
n_bytes: ValueRef,
align: u32) {
let _icx = push_ctxt("call_memcpy");
let ccx = b.ccx;
let ptr_width = &ccx.sess().target.target.target_pointer_width[..];
let key = format!("llvm.memcpy.p0i8.p0i8.i{}", ptr_width);
let memcpy = ccx.get_intrinsic(&key);
let src_ptr = b.pointercast(src, Type::i8p(ccx));
let dst_ptr = b.pointercast(dst, Type::i8p(ccx));
let size = b.intcast(n_bytes, ccx.int_type());
let align = C_i32(ccx, align as i32);
let volatile = C_bool(ccx, false);
b.call(memcpy, &[dst_ptr, src_ptr, size, align, volatile], None);
}
pub fn memcpy_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, dst: ValueRef, src: ValueRef, t: Ty<'tcx>) {
let _icx = push_ctxt("memcpy_ty");
let ccx = bcx.ccx();
if type_is_zero_size(ccx, t) || bcx.unreachable.get() {
return;
}
if t.is_structural() {
let llty = type_of::type_of(ccx, t);
let llsz = llsize_of(ccx, llty);
let llalign = type_of::align_of(ccx, t);
call_memcpy(&B(bcx), dst, src, llsz, llalign as u32);
} else if common::type_is_fat_ptr(bcx.tcx(), t) {
let (data, extra) = load_fat_ptr(bcx, src, t);
store_fat_ptr(bcx, data, extra, dst, t);
} else {
store_ty(bcx, load_ty(bcx, src, t), dst, t);
}
}
pub fn drop_done_fill_mem<'blk, 'tcx>(cx: Block<'blk, 'tcx>, llptr: ValueRef, t: Ty<'tcx>) {
if cx.unreachable.get() {
return;
}
let _icx = push_ctxt("drop_done_fill_mem");
let bcx = cx;
memfill(&B(bcx), llptr, t, adt::DTOR_DONE);
}
pub fn init_zero_mem<'blk, 'tcx>(cx: Block<'blk, 'tcx>, llptr: ValueRef, t: Ty<'tcx>) {
if cx.unreachable.get() {
return;
}
let _icx = push_ctxt("init_zero_mem");
let bcx = cx;
memfill(&B(bcx), llptr, t, 0);
}
// Always use this function instead of storing a constant byte to the memory
// in question. e.g. if you store a zero constant, LLVM will drown in vreg
// allocation for large data structures, and the generated code will be
// awful. (A telltale sign of this is large quantities of
// `mov [byte ptr foo],0` in the generated code.)
fn memfill<'a, 'tcx>(b: &Builder<'a, 'tcx>, llptr: ValueRef, ty: Ty<'tcx>, byte: u8) {
let _icx = push_ctxt("memfill");
let ccx = b.ccx;
let llty = type_of::type_of(ccx, ty);
let llptr = b.pointercast(llptr, Type::i8(ccx).ptr_to());
let llzeroval = C_u8(ccx, byte);
let size = machine::llsize_of(ccx, llty);
let align = C_i32(ccx, type_of::align_of(ccx, ty) as i32);
call_memset(b, llptr, llzeroval, size, align, false);
}
pub fn call_memset<'bcx, 'tcx>(b: &Builder<'bcx, 'tcx>,
ptr: ValueRef,
fill_byte: ValueRef,
size: ValueRef,
align: ValueRef,
volatile: bool) {
let ccx = b.ccx;
let ptr_width = &ccx.sess().target.target.target_pointer_width[..];
let intrinsic_key = format!("llvm.memset.p0i8.i{}", ptr_width);
let llintrinsicfn = ccx.get_intrinsic(&intrinsic_key);
let volatile = C_bool(ccx, volatile);
b.call(llintrinsicfn, &[ptr, fill_byte, size, align, volatile], None);
}
/// In general, when we create an scratch value in an alloca, the
/// creator may not know if the block (that initializes the scratch
/// with the desired value) actually dominates the cleanup associated
/// with the scratch value.
///
/// To deal with this, when we do an alloca (at the *start* of whole
/// function body), we optionally can also set the associated
/// dropped-flag state of the alloca to "dropped."
#[derive(Copy, Clone, Debug)]
pub enum InitAlloca {
/// Indicates that the state should have its associated drop flag
/// set to "dropped" at the point of allocation.
Dropped,
/// Indicates the value of the associated drop flag is irrelevant.
/// The embedded string literal is a programmer provided argument
/// for why. This is a safeguard forcing compiler devs to
/// document; it might be a good idea to also emit this as a
/// comment with the alloca itself when emitting LLVM output.ll.
Uninit(&'static str),
}
pub fn alloc_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
t: Ty<'tcx>,
name: &str) -> ValueRef {
// pnkfelix: I do not know why alloc_ty meets the assumptions for
// passing Uninit, but it was never needed (even back when we had
// the original boolean `zero` flag on `lvalue_scratch_datum`).
alloc_ty_init(bcx, t, InitAlloca::Uninit("all alloc_ty are uninit"), name)
}
/// This variant of `fn alloc_ty` does not necessarily assume that the
/// alloca should be created with no initial value. Instead the caller
/// controls that assumption via the `init` flag.
///
/// Note that if the alloca *is* initialized via `init`, then we will
/// also inject an `llvm.lifetime.start` before that initialization
/// occurs, and thus callers should not call_lifetime_start
/// themselves. But if `init` says "uninitialized", then callers are
/// in charge of choosing where to call_lifetime_start and
/// subsequently populate the alloca.
///
/// (See related discussion on PR #30823.)
pub fn alloc_ty_init<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
t: Ty<'tcx>,
init: InitAlloca,
name: &str) -> ValueRef {
let _icx = push_ctxt("alloc_ty");
let ccx = bcx.ccx();
let ty = type_of::type_of(ccx, t);
assert!(!t.has_param_types());
match init {
InitAlloca::Dropped => alloca_dropped(bcx, t, name),
InitAlloca::Uninit(_) => alloca(bcx, ty, name),
}
}
pub fn alloca_dropped<'blk, 'tcx>(cx: Block<'blk, 'tcx>, ty: Ty<'tcx>, name: &str) -> ValueRef {
let _icx = push_ctxt("alloca_dropped");
let llty = type_of::type_of(cx.ccx(), ty);
if cx.unreachable.get() {
unsafe { return llvm::LLVMGetUndef(llty.ptr_to().to_ref()); }
}
let p = alloca(cx, llty, name);
let b = cx.fcx.ccx.builder();
b.position_before(cx.fcx.alloca_insert_pt.get().unwrap());
// This is just like `call_lifetime_start` (but latter expects a
// Block, which we do not have for `alloca_insert_pt`).
core_lifetime_emit(cx.ccx(), p, Lifetime::Start, |ccx, size, lifetime_start| {
let ptr = b.pointercast(p, Type::i8p(ccx));
b.call(lifetime_start, &[C_u64(ccx, size), ptr], None);
});
memfill(&b, p, ty, adt::DTOR_DONE);
p
}
pub fn alloca(cx: Block, ty: Type, name: &str) -> ValueRef {
let _icx = push_ctxt("alloca");
if cx.unreachable.get() {
unsafe {
return llvm::LLVMGetUndef(ty.ptr_to().to_ref());
}
}
DebugLoc::None.apply(cx.fcx);
Alloca(cx, ty, name)
}
pub fn set_value_name(val: ValueRef, name: &str) {
unsafe {
let name = CString::new(name).unwrap();
llvm::LLVMSetValueName(val, name.as_ptr());
}
}
struct FindNestedReturn {
found: bool,
}
impl FindNestedReturn {
fn new() -> FindNestedReturn {
FindNestedReturn {
found: false,
}
}
}
impl<'v> Visitor<'v> for FindNestedReturn {
fn visit_expr(&mut self, e: &hir::Expr) {
match e.node {
hir::ExprRet(..) => {
self.found = true;
}
_ => intravisit::walk_expr(self, e),
}
}
}
fn build_cfg<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
id: ast::NodeId)
-> (ast::NodeId, Option<cfg::CFG>) {
let blk = match tcx.map.find(id) {
Some(hir_map::NodeItem(i)) => {
match i.node {
hir::ItemFn(_, _, _, _, _, ref blk) => {
blk
}
_ => bug!("unexpected item variant in has_nested_returns"),
}
}
Some(hir_map::NodeTraitItem(trait_item)) => {
match trait_item.node {
hir::MethodTraitItem(_, Some(ref body)) => body,
_ => {
bug!("unexpected variant: trait item other than a provided method in \
has_nested_returns")
}
}
}
Some(hir_map::NodeImplItem(impl_item)) => {
match impl_item.node {
hir::ImplItemKind::Method(_, ref body) => body,
_ => {
bug!("unexpected variant: non-method impl item in has_nested_returns")
}
}
}
Some(hir_map::NodeExpr(e)) => {
match e.node {
hir::ExprClosure(_, _, ref blk, _) => blk,
_ => bug!("unexpected expr variant in has_nested_returns"),
}
}
Some(hir_map::NodeVariant(..)) |
Some(hir_map::NodeStructCtor(..)) => return (ast::DUMMY_NODE_ID, None),
// glue, shims, etc
None if id == ast::DUMMY_NODE_ID => return (ast::DUMMY_NODE_ID, None),
_ => bug!("unexpected variant in has_nested_returns: {}",
tcx.node_path_str(id)),
};
(blk.id, Some(cfg::CFG::new(tcx, blk)))
}
// Checks for the presence of "nested returns" in a function.
// Nested returns are when the inner expression of a return expression
// (the 'expr' in 'return expr') contains a return expression. Only cases
// where the outer return is actually reachable are considered. Implicit
// returns from the end of blocks are considered as well.
//
// This check is needed to handle the case where the inner expression is
// part of a larger expression that may have already partially-filled the
// return slot alloca. This can cause errors related to clean-up due to
// the clobbering of the existing value in the return slot.
fn has_nested_returns(tcx: TyCtxt, cfg: &cfg::CFG, blk_id: ast::NodeId) -> bool {
for index in cfg.graph.depth_traverse(cfg.entry, OUTGOING) {
let n = cfg.graph.node_data(index);
match tcx.map.find(n.id()) {
Some(hir_map::NodeExpr(ex)) => {
if let hir::ExprRet(Some(ref ret_expr)) = ex.node {
let mut visitor = FindNestedReturn::new();
intravisit::walk_expr(&mut visitor, &ret_expr);
if visitor.found {
return true;
}
}
}
Some(hir_map::NodeBlock(blk)) if blk.id == blk_id => {
let mut visitor = FindNestedReturn::new();
walk_list!(&mut visitor, visit_expr, &blk.expr);
if visitor.found {
return true;
}
}
_ => {}
}
}
return false;
}
impl<'blk, 'tcx> FunctionContext<'blk, 'tcx> {
/// Create a function context for the given function.
/// Beware that you must call `fcx.init` or `fcx.bind_args`
/// before doing anything with the returned function context.
pub fn new(ccx: &'blk CrateContext<'blk, 'tcx>,
llfndecl: ValueRef,
fn_ty: FnType,
definition: Option<(Instance<'tcx>, &ty::FnSig<'tcx>, Abi, ast::NodeId)>,
block_arena: &'blk TypedArena<common::BlockS<'blk, 'tcx>>)
-> FunctionContext<'blk, 'tcx> {
let (param_substs, def_id, inlined_id) = match definition {
Some((instance, _, _, inlined_id)) => {
common::validate_substs(instance.substs);
(instance.substs, Some(instance.def), Some(inlined_id))
}
None => (ccx.tcx().mk_substs(Substs::empty()), None, None)
};
let local_id = def_id.and_then(|id| ccx.tcx().map.as_local_node_id(id));
debug!("FunctionContext::new({})",
definition.map_or(String::new(), |d| d.0.to_string()));
let cfg = inlined_id.map(|id| build_cfg(ccx.tcx(), id));
let nested_returns = if let Some((blk_id, Some(ref cfg))) = cfg {
has_nested_returns(ccx.tcx(), cfg, blk_id)
} else {
false
};
let check_attrs = |attrs: &[ast::Attribute]| {
let default_to_mir = ccx.sess().opts.debugging_opts.orbit;
let invert = if default_to_mir { "rustc_no_mir" } else { "rustc_mir" };
(default_to_mir ^ attrs.iter().any(|item| item.check_name(invert)),
attrs.iter().any(|item| item.check_name("no_debug")))
};
let (use_mir, no_debug) = if let Some(id) = local_id {
check_attrs(ccx.tcx().map.attrs(id))
} else if let Some(def_id) = def_id {
check_attrs(&ccx.sess().cstore.item_attrs(def_id))
} else {
check_attrs(&[])
};
let mir = if use_mir {
def_id.and_then(|id| ccx.get_mir(id))
} else {
None
};
let debug_context = if let (false, Some(definition)) = (no_debug, definition) {
let (instance, sig, abi, _) = definition;
debuginfo::create_function_debug_context(ccx, instance, sig, abi, llfndecl)
} else {
debuginfo::empty_function_debug_context(ccx)
};
FunctionContext {
needs_ret_allocas: nested_returns && mir.is_none(),
mir: mir,
llfn: llfndecl,
llretslotptr: Cell::new(None),
param_env: ccx.tcx().empty_parameter_environment(),
alloca_insert_pt: Cell::new(None),
llreturn: Cell::new(None),
landingpad_alloca: Cell::new(None),
lllocals: RefCell::new(NodeMap()),
llupvars: RefCell::new(NodeMap()),
lldropflag_hints: RefCell::new(DropFlagHintsMap::new()),
fn_ty: fn_ty,
param_substs: param_substs,
span: inlined_id.and_then(|id| ccx.tcx().map.opt_span(id)),
block_arena: block_arena,
lpad_arena: TypedArena::new(),
ccx: ccx,
debug_context: debug_context,
scopes: RefCell::new(Vec::new()),
cfg: cfg.and_then(|(_, cfg)| cfg)
}
}
/// Performs setup on a newly created function, creating the entry
/// scope block and allocating space for the return pointer.
pub fn init(&'blk self, skip_retptr: bool, fn_did: Option<DefId>)
-> Block<'blk, 'tcx> {
let entry_bcx = self.new_temp_block("entry-block");
// Use a dummy instruction as the insertion point for all allocas.
// This is later removed in FunctionContext::cleanup.
self.alloca_insert_pt.set(Some(unsafe {
Load(entry_bcx, C_null(Type::i8p(self.ccx)));
llvm::LLVMGetFirstInstruction(entry_bcx.llbb)
}));
if !self.fn_ty.ret.is_ignore() && !skip_retptr {
// We normally allocate the llretslotptr, unless we
// have been instructed to skip it for immediate return
// values, or there is nothing to return at all.
// We create an alloca to hold a pointer of type `ret.original_ty`
// which will hold the pointer to the right alloca which has the
// final ret value
let llty = self.fn_ty.ret.memory_ty(self.ccx);
let slot = if self.needs_ret_allocas {
// Let's create the stack slot
let slot = AllocaFcx(self, llty.ptr_to(), "llretslotptr");
// and if we're using an out pointer, then store that in our newly made slot
if self.fn_ty.ret.is_indirect() {
let outptr = get_param(self.llfn, 0);
let b = self.ccx.builder();
b.position_before(self.alloca_insert_pt.get().unwrap());
b.store(outptr, slot);
}
slot
} else {
// But if there are no nested returns, we skip the indirection
// and have a single retslot
if self.fn_ty.ret.is_indirect() {
get_param(self.llfn, 0)
} else {
AllocaFcx(self, llty, "sret_slot")
}
};
self.llretslotptr.set(Some(slot));
}
// Create the drop-flag hints for every unfragmented path in the function.
let tcx = self.ccx.tcx();
let tables = tcx.tables.borrow();
let mut hints = self.lldropflag_hints.borrow_mut();
let fragment_infos = tcx.fragment_infos.borrow();
// Intern table for drop-flag hint datums.
let mut seen = HashMap::new();
let fragment_infos = fn_did.and_then(|did| fragment_infos.get(&did));
if let Some(fragment_infos) = fragment_infos {
for &info in fragment_infos {
let make_datum = |id| {
let init_val = C_u8(self.ccx, adt::DTOR_NEEDED_HINT);
let llname = &format!("dropflag_hint_{}", id);
debug!("adding hint {}", llname);
let ty = tcx.types.u8;
let ptr = alloc_ty(entry_bcx, ty, llname);
Store(entry_bcx, init_val, ptr);
let flag = datum::Lvalue::new_dropflag_hint("FunctionContext::init");
datum::Datum::new(ptr, ty, flag)
};
let (var, datum) = match info {
ty::FragmentInfo::Moved { var, .. } |
ty::FragmentInfo::Assigned { var, .. } => {
let opt_datum = seen.get(&var).cloned().unwrap_or_else(|| {
let ty = tables.node_types[&var];
if self.type_needs_drop(ty) {
let datum = make_datum(var);
seen.insert(var, Some(datum.clone()));
Some(datum)
} else {
// No drop call needed, so we don't need a dropflag hint
None
}
});
if let Some(datum) = opt_datum {
(var, datum)
} else {
continue
}
}
};
match info {
ty::FragmentInfo::Moved { move_expr: expr_id, .. } => {
debug!("FragmentInfo::Moved insert drop hint for {}", expr_id);
hints.insert(expr_id, DropHint::new(var, datum));
}
ty::FragmentInfo::Assigned { assignee_id: expr_id, .. } => {
debug!("FragmentInfo::Assigned insert drop hint for {}", expr_id);
hints.insert(expr_id, DropHint::new(var, datum));
}
}
}
}
entry_bcx
}
/// Creates lvalue datums for each of the incoming function arguments,
/// matches all argument patterns against them to produce bindings,
/// and returns the entry block (see FunctionContext::init).
fn bind_args(&'blk self,
args: &[hir::Arg],
abi: Abi,
id: ast::NodeId,
closure_env: closure::ClosureEnv,
arg_scope: cleanup::CustomScopeIndex)
-> Block<'blk, 'tcx> {
let _icx = push_ctxt("FunctionContext::bind_args");
let fn_did = self.ccx.tcx().map.local_def_id(id);
let mut bcx = self.init(false, Some(fn_did));
let arg_scope_id = cleanup::CustomScope(arg_scope);
let mut idx = 0;
let mut llarg_idx = self.fn_ty.ret.is_indirect() as usize;
let has_tupled_arg = match closure_env {
closure::ClosureEnv::NotClosure => abi == Abi::RustCall,
closure::ClosureEnv::Closure(..) => {
closure_env.load(bcx, arg_scope_id);
let env_arg = &self.fn_ty.args[idx];
idx += 1;
if env_arg.pad.is_some() {
llarg_idx += 1;
}
if !env_arg.is_ignore() {
llarg_idx += 1;
}
false
}
};
let tupled_arg_id = if has_tupled_arg {
args[args.len() - 1].id
} else {
ast::DUMMY_NODE_ID
};
// Return an array wrapping the ValueRefs that we get from `get_param` for
// each argument into datums.
//
// For certain mode/type combinations, the raw llarg values are passed
// by value. However, within the fn body itself, we want to always
// have all locals and arguments be by-ref so that we can cancel the
// cleanup and for better interaction with LLVM's debug info. So, if
// the argument would be passed by value, we store it into an alloca.
// This alloca should be optimized away by LLVM's mem-to-reg pass in
// the event it's not truly needed.
let uninit_reason = InitAlloca::Uninit("fn_arg populate dominates dtor");
for hir_arg in args {
let arg_ty = node_id_type(bcx, hir_arg.id);
let arg_datum = if hir_arg.id != tupled_arg_id {
let arg = &self.fn_ty.args[idx];
idx += 1;
if arg.is_indirect() && bcx.sess().opts.debuginfo != FullDebugInfo {
// Don't copy an indirect argument to an alloca, the caller
// already put it in a temporary alloca and gave it up, unless
// we emit extra-debug-info, which requires local allocas :(.
let llarg = get_param(self.llfn, llarg_idx as c_uint);
llarg_idx += 1;
self.schedule_lifetime_end(arg_scope_id, llarg);
self.schedule_drop_mem(arg_scope_id, llarg, arg_ty, None);
datum::Datum::new(llarg,
arg_ty,
datum::Lvalue::new("FunctionContext::bind_args"))
} else {
unpack_datum!(bcx, datum::lvalue_scratch_datum(bcx, arg_ty, "",
uninit_reason,
arg_scope_id, |bcx, dst| {
debug!("FunctionContext::bind_args: {:?}: {:?}", hir_arg, arg_ty);
let b = &bcx.build();
if common::type_is_fat_ptr(bcx.tcx(), arg_ty) {
let meta = &self.fn_ty.args[idx];
idx += 1;
arg.store_fn_arg(b, &mut llarg_idx, expr::get_dataptr(bcx, dst));
meta.store_fn_arg(b, &mut llarg_idx, expr::get_meta(bcx, dst));
} else {
arg.store_fn_arg(b, &mut llarg_idx, dst);
}
bcx
}))
}
} else {
// FIXME(pcwalton): Reduce the amount of code bloat this is responsible for.
let tupled_arg_tys = match arg_ty.sty {
ty::TyTuple(ref tys) => tys,
_ => bug!("last argument of `rust-call` fn isn't a tuple?!")
};
unpack_datum!(bcx, datum::lvalue_scratch_datum(bcx,
arg_ty,
"tupled_args",
uninit_reason,
arg_scope_id,
|bcx, llval| {
debug!("FunctionContext::bind_args: tupled {:?}: {:?}", hir_arg, arg_ty);
for (j, &tupled_arg_ty) in tupled_arg_tys.iter().enumerate() {
let dst = StructGEP(bcx, llval, j);
let arg = &self.fn_ty.args[idx];
idx += 1;
let b = &bcx.build();
if common::type_is_fat_ptr(bcx.tcx(), tupled_arg_ty) {
let meta = &self.fn_ty.args[idx];
idx += 1;
arg.store_fn_arg(b, &mut llarg_idx, expr::get_dataptr(bcx, dst));
meta.store_fn_arg(b, &mut llarg_idx, expr::get_meta(bcx, dst));
} else {
arg.store_fn_arg(b, &mut llarg_idx, dst);
}
}
bcx
}))
};
let pat = &hir_arg.pat;
bcx = if let Some(name) = simple_name(pat) {
// Generate nicer LLVM for the common case of fn a pattern
// like `x: T`
set_value_name(arg_datum.val, &bcx.name(name));
self.lllocals.borrow_mut().insert(pat.id, arg_datum);
bcx
} else {
// General path. Copy out the values that are used in the
// pattern.
_match::bind_irrefutable_pat(bcx, pat, arg_datum.match_input(), arg_scope_id)
};
debuginfo::create_argument_metadata(bcx, hir_arg);
}
bcx
}
/// Ties up the llstaticallocas -> llloadenv -> lltop edges,
/// and builds the return block.
pub fn finish(&'blk self, last_bcx: Block<'blk, 'tcx>,
ret_debug_loc: DebugLoc) {
let _icx = push_ctxt("FunctionContext::finish");
let ret_cx = match self.llreturn.get() {
Some(llreturn) => {
if !last_bcx.terminated.get() {
Br(last_bcx, llreturn, DebugLoc::None);
}
raw_block(self, llreturn)
}
None => last_bcx,
};
self.build_return_block(ret_cx, ret_debug_loc);
DebugLoc::None.apply(self);
self.cleanup();
}
// Builds the return block for a function.
pub fn build_return_block(&self, ret_cx: Block<'blk, 'tcx>,
ret_debug_location: DebugLoc) {
if self.llretslotptr.get().is_none() ||
ret_cx.unreachable.get() ||
(!self.needs_ret_allocas && self.fn_ty.ret.is_indirect()) {
return RetVoid(ret_cx, ret_debug_location);
}
let retslot = if self.needs_ret_allocas {
Load(ret_cx, self.llretslotptr.get().unwrap())
} else {
self.llretslotptr.get().unwrap()
};
let retptr = Value(retslot);
let llty = self.fn_ty.ret.original_ty;
match (retptr.get_dominating_store(ret_cx), self.fn_ty.ret.cast) {
// If there's only a single store to the ret slot, we can directly return
// the value that was stored and omit the store and the alloca.
// However, we only want to do this when there is no cast needed.
(Some(s), None) => {
let mut retval = s.get_operand(0).unwrap().get();
s.erase_from_parent();
if retptr.has_no_uses() {
retptr.erase_from_parent();
}
if self.fn_ty.ret.is_indirect() {
Store(ret_cx, retval, get_param(self.llfn, 0));
RetVoid(ret_cx, ret_debug_location)
} else {
if llty == Type::i1(self.ccx) {
retval = Trunc(ret_cx, retval, llty);
}
Ret(ret_cx, retval, ret_debug_location)
}
}
(_, cast_ty) if self.fn_ty.ret.is_indirect() => {
// Otherwise, copy the return value to the ret slot.
assert_eq!(cast_ty, None);
let llsz = llsize_of(self.ccx, self.fn_ty.ret.ty);
let llalign = llalign_of_min(self.ccx, self.fn_ty.ret.ty);
call_memcpy(&B(ret_cx), get_param(self.llfn, 0),
retslot, llsz, llalign as u32);
RetVoid(ret_cx, ret_debug_location)
}
(_, Some(cast_ty)) => {
let load = Load(ret_cx, PointerCast(ret_cx, retslot, cast_ty.ptr_to()));
let llalign = llalign_of_min(self.ccx, self.fn_ty.ret.ty);
unsafe {
llvm::LLVMSetAlignment(load, llalign);
}
Ret(ret_cx, load, ret_debug_location)
}
(_, None) => {
let retval = if llty == Type::i1(self.ccx) {
let val = LoadRangeAssert(ret_cx, retslot, 0, 2, llvm::False);
Trunc(ret_cx, val, llty)
} else {
Load(ret_cx, retslot)
};
Ret(ret_cx, retval, ret_debug_location)
}
}
}
}
/// Builds an LLVM function out of a source function.
///
/// If the function closes over its environment a closure will be returned.
pub fn trans_closure<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
decl: &hir::FnDecl,
body: &hir::Block,
llfndecl: ValueRef,
instance: Instance<'tcx>,
inlined_id: ast::NodeId,
sig: &ty::FnSig<'tcx>,
abi: Abi,
closure_env: closure::ClosureEnv) {
ccx.stats().n_closures.set(ccx.stats().n_closures.get() + 1);
let _icx = push_ctxt("trans_closure");
if !ccx.sess().no_landing_pads() {
attributes::emit_uwtable(llfndecl, true);
}
// this is an info! to allow collecting monomorphization statistics
// and to allow finding the last function before LLVM aborts from
// release builds.
info!("trans_closure(..., {})", instance);
let fn_ty = FnType::new(ccx, abi, sig, &[]);
let (arena, fcx): (TypedArena<_>, FunctionContext);
arena = TypedArena::new();
fcx = FunctionContext::new(ccx,
llfndecl,
fn_ty,
Some((instance, sig, abi, inlined_id)),
&arena);
if fcx.mir.is_some() {
return mir::trans_mir(&fcx);
}
debuginfo::fill_scope_map_for_function(&fcx, decl, body, inlined_id);
// cleanup scope for the incoming arguments
let fn_cleanup_debug_loc = debuginfo::get_cleanup_debug_loc_for_ast_node(
ccx, inlined_id, body.span, true);
let arg_scope = fcx.push_custom_cleanup_scope_with_debug_loc(fn_cleanup_debug_loc);
// Set up arguments to the function.
debug!("trans_closure: function: {:?}", Value(fcx.llfn));
let bcx = fcx.bind_args(&decl.inputs, abi, inlined_id, closure_env, arg_scope);
// Up until here, IR instructions for this function have explicitly not been annotated with
// source code location, so we don't step into call setup code. From here on, source location
// emitting should be enabled.
debuginfo::start_emitting_source_locations(&fcx);
let dest = if fcx.fn_ty.ret.is_ignore() {
expr::Ignore
} else {
expr::SaveIn(fcx.get_ret_slot(bcx, "iret_slot"))
};
// This call to trans_block is the place where we bridge between
// translation calls that don't have a return value (trans_crate,
// trans_mod, trans_item, et cetera) and those that do
// (trans_block, trans_expr, et cetera).
let mut bcx = controlflow::trans_block(bcx, body, dest);
match dest {
expr::SaveIn(slot) if fcx.needs_ret_allocas => {
Store(bcx, slot, fcx.llretslotptr.get().unwrap());
}
_ => {}
}
match fcx.llreturn.get() {
Some(_) => {
Br(bcx, fcx.return_exit_block(), DebugLoc::None);
fcx.pop_custom_cleanup_scope(arg_scope);
}
None => {
// Microoptimization writ large: avoid creating a separate
// llreturn basic block
bcx = fcx.pop_and_trans_custom_cleanup_scope(bcx, arg_scope);
}
};
// Put return block after all other blocks.
// This somewhat improves single-stepping experience in debugger.
unsafe {
let llreturn = fcx.llreturn.get();
if let Some(llreturn) = llreturn {
llvm::LLVMMoveBasicBlockAfter(llreturn, bcx.llbb);
}
}
// Insert the mandatory first few basic blocks before lltop.
fcx.finish(bcx, fn_cleanup_debug_loc.debug_loc());
}
pub fn trans_instance<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, instance: Instance<'tcx>) {
let local_instance = inline::maybe_inline_instance(ccx, instance);
let fn_node_id = ccx.tcx().map.as_local_node_id(local_instance.def).unwrap();
let _s = StatRecorder::new(ccx, ccx.tcx().node_path_str(fn_node_id));
debug!("trans_instance(instance={:?})", instance);
let _icx = push_ctxt("trans_instance");
let item = ccx.tcx().map.find(fn_node_id).unwrap();
let fn_ty = ccx.tcx().lookup_item_type(instance.def).ty;
let fn_ty = ccx.tcx().erase_regions(&fn_ty);
let fn_ty = monomorphize::apply_param_substs(ccx.tcx(), instance.substs, &fn_ty);
let sig = ccx.tcx().erase_late_bound_regions(fn_ty.fn_sig());
let sig = ccx.tcx().normalize_associated_type(&sig);
let abi = fn_ty.fn_abi();
let lldecl = match ccx.instances().borrow().get(&local_instance) {
Some(&val) => val,
None => bug!("Instance `{:?}` not already declared", instance)
};
match item {
hir_map::NodeItem(&hir::Item {
node: hir::ItemFn(ref decl, _, _, _, _, ref body), ..
}) |
hir_map::NodeTraitItem(&hir::TraitItem {
node: hir::MethodTraitItem(
hir::MethodSig { ref decl, .. }, Some(ref body)), ..
}) |
hir_map::NodeImplItem(&hir::ImplItem {
node: hir::ImplItemKind::Method(
hir::MethodSig { ref decl, .. }, ref body), ..
}) => {
trans_closure(ccx, decl, body, lldecl, instance,
fn_node_id, &sig, abi, closure::ClosureEnv::NotClosure);
}
_ => bug!("Instance is a {:?}?", item)
}
}
pub fn trans_named_tuple_constructor<'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
ctor_ty: Ty<'tcx>,
disr: Disr,
args: CallArgs,
dest: expr::Dest,
debug_loc: DebugLoc)
-> Result<'blk, 'tcx> {
let ccx = bcx.fcx.ccx;
let sig = ccx.tcx().erase_late_bound_regions(&ctor_ty.fn_sig());
let sig = ccx.tcx().normalize_associated_type(&sig);
let result_ty = sig.output.unwrap();
// Get location to store the result. If the user does not care about
// the result, just make a stack slot
let llresult = match dest {
expr::SaveIn(d) => d,
expr::Ignore => {
if !type_is_zero_size(ccx, result_ty) {
let llresult = alloc_ty(bcx, result_ty, "constructor_result");
call_lifetime_start(bcx, llresult);
llresult
} else {
C_undef(type_of::type_of(ccx, result_ty).ptr_to())
}
}
};
if !type_is_zero_size(ccx, result_ty) {
match args {
ArgExprs(exprs) => {
let fields = exprs.iter().map(|x| &**x).enumerate().collect::<Vec<_>>();
bcx = expr::trans_adt(bcx,
result_ty,
disr,
&fields[..],
None,
expr::SaveIn(llresult),
debug_loc);
}
_ => bug!("expected expr as arguments for variant/struct tuple constructor"),
}
} else {
// Just eval all the expressions (if any). Since expressions in Rust can have arbitrary
// contents, there could be side-effects we need from them.
match args {
ArgExprs(exprs) => {
for expr in exprs {
bcx = expr::trans_into(bcx, expr, expr::Ignore);
}
}
_ => (),
}
}
// If the caller doesn't care about the result
// drop the temporary we made
let bcx = match dest {
expr::SaveIn(_) => bcx,
expr::Ignore => {
let bcx = glue::drop_ty(bcx, llresult, result_ty, debug_loc);
if !type_is_zero_size(ccx, result_ty) {
call_lifetime_end(bcx, llresult);
}
bcx
}
};
Result::new(bcx, llresult)
}
pub fn trans_ctor_shim<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
ctor_id: ast::NodeId,
disr: Disr,
param_substs: &'tcx Substs<'tcx>,
llfndecl: ValueRef) {
let ctor_ty = ccx.tcx().node_id_to_type(ctor_id);
let ctor_ty = monomorphize::apply_param_substs(ccx.tcx(), param_substs, &ctor_ty);
let sig = ccx.tcx().erase_late_bound_regions(&ctor_ty.fn_sig());
let sig = ccx.tcx().normalize_associated_type(&sig);
let fn_ty = FnType::new(ccx, Abi::Rust, &sig, &[]);
let (arena, fcx): (TypedArena<_>, FunctionContext);
arena = TypedArena::new();
fcx = FunctionContext::new(ccx, llfndecl, fn_ty, None, &arena);
let bcx = fcx.init(false, None);
assert!(!fcx.needs_ret_allocas);
if !fcx.fn_ty.ret.is_ignore() {
let dest = fcx.get_ret_slot(bcx, "eret_slot");
let dest_val = adt::MaybeSizedValue::sized(dest); // Can return unsized value
let repr = adt::represent_type(ccx, sig.output.unwrap());
let mut llarg_idx = fcx.fn_ty.ret.is_indirect() as usize;
let mut arg_idx = 0;
for (i, arg_ty) in sig.inputs.into_iter().enumerate() {
let lldestptr = adt::trans_field_ptr(bcx, &repr, dest_val, Disr::from(disr), i);
let arg = &fcx.fn_ty.args[arg_idx];
arg_idx += 1;
let b = &bcx.build();
if common::type_is_fat_ptr(bcx.tcx(), arg_ty) {
let meta = &fcx.fn_ty.args[arg_idx];
arg_idx += 1;
arg.store_fn_arg(b, &mut llarg_idx, expr::get_dataptr(bcx, lldestptr));
meta.store_fn_arg(b, &mut llarg_idx, expr::get_meta(bcx, lldestptr));
} else {
arg.store_fn_arg(b, &mut llarg_idx, lldestptr);
}
}
adt::trans_set_discr(bcx, &repr, dest, disr);
}
fcx.finish(bcx, DebugLoc::None);
}
pub fn llvm_linkage_by_name(name: &str) -> Option<Linkage> {
// Use the names from src/llvm/docs/LangRef.rst here. Most types are only
// applicable to variable declarations and may not really make sense for
// Rust code in the first place but whitelist them anyway and trust that
// the user knows what s/he's doing. Who knows, unanticipated use cases
// may pop up in the future.
//
// ghost, dllimport, dllexport and linkonce_odr_autohide are not supported
// and don't have to be, LLVM treats them as no-ops.
match name {
"appending" => Some(llvm::AppendingLinkage),
"available_externally" => Some(llvm::AvailableExternallyLinkage),
"common" => Some(llvm::CommonLinkage),
"extern_weak" => Some(llvm::ExternalWeakLinkage),
"external" => Some(llvm::ExternalLinkage),
"internal" => Some(llvm::InternalLinkage),
"linkonce" => Some(llvm::LinkOnceAnyLinkage),
"linkonce_odr" => Some(llvm::LinkOnceODRLinkage),
"private" => Some(llvm::PrivateLinkage),
"weak" => Some(llvm::WeakAnyLinkage),
"weak_odr" => Some(llvm::WeakODRLinkage),
_ => None,
}
}
pub fn set_link_section(ccx: &CrateContext,
llval: ValueRef,
attrs: &[ast::Attribute]) {
if let Some(sect) = attr::first_attr_value_str_by_name(attrs, "link_section") {
if contains_null(&sect) {
ccx.sess().fatal(&format!("Illegal null byte in link_section value: `{}`", &sect));
}
unsafe {
let buf = CString::new(sect.as_bytes()).unwrap();
llvm::LLVMSetSection(llval, buf.as_ptr());
}
}
}
/// Create the `main` function which will initialise the rust runtime and call
/// users’ main function.
pub fn maybe_create_entry_wrapper(ccx: &CrateContext) {
let (main_def_id, span) = match *ccx.sess().entry_fn.borrow() {
Some((id, span)) => {
(ccx.tcx().map.local_def_id(id), span)
}
None => return,
};
// check for the #[rustc_error] annotation, which forces an
// error in trans. This is used to write compile-fail tests
// that actually test that compilation succeeds without
// reporting an error.
if ccx.tcx().has_attr(main_def_id, "rustc_error") {
ccx.tcx().sess.span_fatal(span, "compilation successful");
}
let instance = Instance::mono(ccx.shared(), main_def_id);
if !ccx.codegen_unit().contains_item(&TransItem::Fn(instance)) {
// We want to create the wrapper in the same codegen unit as Rust's main
// function.
return;
}
let main_llfn = Callee::def(ccx, main_def_id, instance.substs).reify(ccx).val;
let et = ccx.sess().entry_type.get().unwrap();
match et {
config::EntryMain => {
create_entry_fn(ccx, span, main_llfn, true);
}
config::EntryStart => create_entry_fn(ccx, span, main_llfn, false),
config::EntryNone => {} // Do nothing.
}
fn create_entry_fn(ccx: &CrateContext,
sp: Span,
rust_main: ValueRef,
use_start_lang_item: bool) {
let llfty = Type::func(&[ccx.int_type(), Type::i8p(ccx).ptr_to()], &ccx.int_type());
if declare::get_defined_value(ccx, "main").is_some() {
// FIXME: We should be smart and show a better diagnostic here.
ccx.sess().struct_span_err(sp, "entry symbol `main` defined multiple times")
.help("did you use #[no_mangle] on `fn main`? Use #[start] instead")
.emit();
ccx.sess().abort_if_errors();
bug!();
}
let llfn = declare::declare_cfn(ccx, "main", llfty);
let llbb = unsafe {
llvm::LLVMAppendBasicBlockInContext(ccx.llcx(), llfn, "top\0".as_ptr() as *const _)
};
let bld = ccx.raw_builder();
unsafe {
llvm::LLVMPositionBuilderAtEnd(bld, llbb);
debuginfo::gdb::insert_reference_to_gdb_debug_scripts_section_global(ccx);
let (start_fn, args) = if use_start_lang_item {
let start_def_id = match ccx.tcx().lang_items.require(StartFnLangItem) {
Ok(id) => id,
Err(s) => ccx.sess().fatal(&s)
};
let empty_substs = ccx.tcx().mk_substs(Substs::empty());
let start_fn = Callee::def(ccx, start_def_id, empty_substs).reify(ccx).val;
let args = {
let opaque_rust_main =
llvm::LLVMBuildPointerCast(bld,
rust_main,
Type::i8p(ccx).to_ref(),
"rust_main\0".as_ptr() as *const _);
vec![opaque_rust_main, get_param(llfn, 0), get_param(llfn, 1)]
};
(start_fn, args)
} else {
debug!("using user-defined start fn");
let args = vec![get_param(llfn, 0 as c_uint), get_param(llfn, 1 as c_uint)];
(rust_main, args)
};
let result = llvm::LLVMRustBuildCall(bld,
start_fn,
args.as_ptr(),
args.len() as c_uint,
ptr::null_mut(),
noname());
llvm::LLVMBuildRet(bld, result);
}
}
}
fn contains_null(s: &str) -> bool {
s.bytes().any(|b| b == 0)
}
fn write_metadata(cx: &SharedCrateContext,
reachable_ids: &NodeSet) -> Vec<u8> {
use flate;
let any_library = cx.sess()
.crate_types
.borrow()
.iter()
.any(|ty| *ty != config::CrateTypeExecutable);
if !any_library {
return Vec::new();
}
let cstore = &cx.tcx().sess.cstore;
let metadata = cstore.encode_metadata(cx.tcx(),
cx.export_map(),
cx.link_meta(),
reachable_ids,
cx.mir_map(),
cx.tcx().map.krate());
let mut compressed = cstore.metadata_encoding_version().to_vec();
compressed.extend_from_slice(&flate::deflate_bytes(&metadata));
let llmeta = C_bytes_in_context(cx.metadata_llcx(), &compressed[..]);
let llconst = C_struct_in_context(cx.metadata_llcx(), &[llmeta], false);
let name = cx.metadata_symbol_name();
let buf = CString::new(name).unwrap();
let llglobal = unsafe {
llvm::LLVMAddGlobal(cx.metadata_llmod(), val_ty(llconst).to_ref(), buf.as_ptr())
};
unsafe {
llvm::LLVMSetInitializer(llglobal, llconst);
let name =
cx.tcx().sess.cstore.metadata_section_name(&cx.sess().target.target);
let name = CString::new(name).unwrap();
llvm::LLVMSetSection(llglobal, name.as_ptr())
}
return metadata;
}
/// Find any symbols that are defined in one compilation unit, but not declared
/// in any other compilation unit. Give these symbols internal linkage.
fn internalize_symbols<'a, 'tcx>(sess: &Session,
ccxs: &CrateContextList<'a, 'tcx>,
symbol_map: &SymbolMap<'tcx>,
reachable: &FnvHashSet<&str>) {
let scx = ccxs.shared();
let tcx = scx.tcx();
// In incr. comp. mode, we can't necessarily see all refs since we
// don't generate LLVM IR for reused modules, so skip this
// step. Later we should get smarter.
if sess.opts.debugging_opts.incremental.is_some() {
return;
}
// 'unsafe' because we are holding on to CStr's from the LLVM module within
// this block.
unsafe {
let mut referenced_somewhere = FnvHashSet();
// Collect all symbols that need to stay externally visible because they
// are referenced via a declaration in some other codegen unit.
for ccx in ccxs.iter_need_trans() {
for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
let linkage = llvm::LLVMGetLinkage(val);
// We only care about external declarations (not definitions)
// and available_externally definitions.
let is_available_externally = linkage == llvm::AvailableExternallyLinkage as c_uint;
let is_decl = llvm::LLVMIsDeclaration(val) != 0;
if is_decl || is_available_externally {
let symbol_name = CStr::from_ptr(llvm::LLVMGetValueName(val));
referenced_somewhere.insert(symbol_name);
}
}
}
// Also collect all symbols for which we cannot adjust linkage, because
// it is fixed by some directive in the source code (e.g. #[no_mangle]).
let linkage_fixed_explicitly: FnvHashSet<_> = scx
.translation_items()
.borrow()
.iter()
.cloned()
.filter(|trans_item|{
let def_id = match *trans_item {
TransItem::DropGlue(..) => {
return false
},
TransItem::Fn(ref instance) => {
instance.def
}
TransItem::Static(node_id) => {
tcx.map.local_def_id(node_id)
}
};
trans_item.explicit_linkage(tcx).is_some() ||
attr::contains_extern_indicator(tcx.sess.diagnostic(),
&tcx.get_attrs(def_id))
})
.map(|trans_item| symbol_map.get_or_compute(scx, trans_item))
.collect();
// Examine each external definition. If the definition is not used in
// any other compilation unit, and is not reachable from other crates,
// then give it internal linkage.
for ccx in ccxs.iter_need_trans() {
for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
let linkage = llvm::LLVMGetLinkage(val);
let is_externally_visible = (linkage == llvm::ExternalLinkage as c_uint) ||
(linkage == llvm::LinkOnceODRLinkage as c_uint) ||
(linkage == llvm::WeakODRLinkage as c_uint);
let is_definition = llvm::LLVMIsDeclaration(val) == 0;
// If this is a definition (as opposed to just a declaration)
// and externally visible, check if we can internalize it
if is_definition && is_externally_visible {
let name_cstr = CStr::from_ptr(llvm::LLVMGetValueName(val));
let name_str = name_cstr.to_str().unwrap();
let name_cow = Cow::Borrowed(name_str);
let is_referenced_somewhere = referenced_somewhere.contains(&name_cstr);
let is_reachable = reachable.contains(&name_str);
let has_fixed_linkage = linkage_fixed_explicitly.contains(&name_cow);
if !is_referenced_somewhere && !is_reachable && !has_fixed_linkage {
llvm::LLVMSetLinkage(val, llvm::InternalLinkage);
llvm::LLVMSetDLLStorageClass(val,
llvm::DLLStorageClass::Default);
llvm::UnsetComdat(val);
}
}
}
}
}
}
// Create a `__imp_<symbol> = &symbol` global for every public static `symbol`.
// This is required to satisfy `dllimport` references to static data in .rlibs
// when using MSVC linker. We do this only for data, as linker can fix up
// code references on its own.
// See #26591, #27438
fn create_imps(cx: &CrateContextList) {
// The x86 ABI seems to require that leading underscores are added to symbol
// names, so we need an extra underscore on 32-bit. There's also a leading
// '\x01' here which disables LLVM's symbol mangling (e.g. no extra
// underscores added in front).
let prefix = if cx.shared().sess().target.target.target_pointer_width == "32" {
"\x01__imp__"
} else {
"\x01__imp_"
};
unsafe {
for ccx in cx.iter_need_trans() {
let exported: Vec<_> = iter_globals(ccx.llmod())
.filter(|&val| {
llvm::LLVMGetLinkage(val) ==
llvm::ExternalLinkage as c_uint &&
llvm::LLVMIsDeclaration(val) == 0
})
.collect();
let i8p_ty = Type::i8p(&ccx);
for val in exported {
let name = CStr::from_ptr(llvm::LLVMGetValueName(val));
let mut imp_name = prefix.as_bytes().to_vec();
imp_name.extend(name.to_bytes());
let imp_name = CString::new(imp_name).unwrap();
let imp = llvm::LLVMAddGlobal(ccx.llmod(),
i8p_ty.to_ref(),
imp_name.as_ptr() as *const _);
let init = llvm::LLVMConstBitCast(val, i8p_ty.to_ref());
llvm::LLVMSetInitializer(imp, init);
llvm::LLVMSetLinkage(imp, llvm::ExternalLinkage);
}
}
}
}
struct ValueIter {
cur: ValueRef,
step: unsafe extern "C" fn(ValueRef) -> ValueRef,
}
impl Iterator for ValueIter {
type Item = ValueRef;
fn next(&mut self) -> Option<ValueRef> {
let old = self.cur;
if !old.is_null() {
self.cur = unsafe { (self.step)(old) };
Some(old)
} else {
None
}
}
}
fn iter_globals(llmod: llvm::ModuleRef) -> ValueIter {
unsafe {
ValueIter {
cur: llvm::LLVMGetFirstGlobal(llmod),
step: llvm::LLVMGetNextGlobal,
}
}
}
fn iter_functions(llmod: llvm::ModuleRef) -> ValueIter {
unsafe {
ValueIter {
cur: llvm::LLVMGetFirstFunction(llmod),
step: llvm::LLVMGetNextFunction,
}
}
}
/// The context provided lists a set of reachable ids as calculated by
/// middle::reachable, but this contains far more ids and symbols than we're
/// actually exposing from the object file. This function will filter the set in
/// the context to the set of ids which correspond to symbols that are exposed
/// from the object file being generated.
///
/// This list is later used by linkers to determine the set of symbols needed to
/// be exposed from a dynamic library and it's also encoded into the metadata.
pub fn filter_reachable_ids(tcx: TyCtxt, reachable: NodeSet) -> NodeSet {
reachable.into_iter().filter(|&id| {
// Next, we want to ignore some FFI functions that are not exposed from
// this crate. Reachable FFI functions can be lumped into two
// categories:
//
// 1. Those that are included statically via a static library
// 2. Those included otherwise (e.g. dynamically or via a framework)
//
// Although our LLVM module is not literally emitting code for the
// statically included symbols, it's an export of our library which
// needs to be passed on to the linker and encoded in the metadata.
//
// As a result, if this id is an FFI item (foreign item) then we only
// let it through if it's included statically.
match tcx.map.get(id) {
hir_map::NodeForeignItem(..) => {
tcx.sess.cstore.is_statically_included_foreign_item(id)
}
// Only consider nodes that actually have exported symbols.
hir_map::NodeItem(&hir::Item {
node: hir::ItemStatic(..), .. }) |
hir_map::NodeItem(&hir::Item {
node: hir::ItemFn(..), .. }) |
hir_map::NodeImplItem(&hir::ImplItem {
node: hir::ImplItemKind::Method(..), .. }) => {
let def_id = tcx.map.local_def_id(id);
let scheme = tcx.lookup_item_type(def_id);
scheme.generics.types.is_empty()
}
_ => false
}
}).collect()
}
pub fn trans_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
mir_map: &MirMap<'tcx>,
analysis: ty::CrateAnalysis)
-> CrateTranslation {
let _task = tcx.dep_graph.in_task(DepNode::TransCrate);
// Be careful with this krate: obviously it gives access to the
// entire contents of the krate. So if you push any subtasks of
// `TransCrate`, you need to be careful to register "reads" of the
// particular items that will be processed.
let krate = tcx.map.krate();
let ty::CrateAnalysis { export_map, reachable, name, .. } = analysis;
let reachable = filter_reachable_ids(tcx, reachable);
let check_overflow = if let Some(v) = tcx.sess.opts.debugging_opts.force_overflow_checks {
v
} else {
tcx.sess.opts.debug_assertions
};
let check_dropflag = if let Some(v) = tcx.sess.opts.debugging_opts.force_dropflag_checks {
v
} else {
tcx.sess.opts.debug_assertions
};
let link_meta = link::build_link_meta(tcx, name);
let shared_ccx = SharedCrateContext::new(tcx,
&mir_map,
export_map,
Sha256::new(),
link_meta.clone(),
reachable,
check_overflow,
check_dropflag);
// Translate the metadata.
let metadata = time(tcx.sess.time_passes(), "write metadata", || {
write_metadata(&shared_ccx, shared_ccx.reachable())
});
let metadata_module = ModuleTranslation {
name: "metadata".to_string(),
symbol_name_hash: 0, // we always rebuild metadata, at least for now
source: ModuleSource::Translated(ModuleLlvm {
llcx: shared_ccx.metadata_llcx(),
llmod: shared_ccx.metadata_llmod(),
}),
};
let no_builtins = attr::contains_name(&krate.attrs, "no_builtins");
// Run the translation item collector and partition the collected items into
// codegen units.
let (codegen_units, symbol_map) = collect_and_partition_translation_items(&shared_ccx);
let symbol_map = Rc::new(symbol_map);
let previous_work_products = trans_reuse_previous_work_products(tcx,
&codegen_units,
&symbol_map);
let crate_context_list = CrateContextList::new(&shared_ccx,
codegen_units,
previous_work_products,
symbol_map.clone());
let modules: Vec<_> = crate_context_list.iter_all()
.map(|ccx| {
let source = match ccx.previous_work_product() {
Some(buf) => ModuleSource::Preexisting(buf.clone()),
None => ModuleSource::Translated(ModuleLlvm {
llcx: ccx.llcx(),
llmod: ccx.llmod(),
}),
};
ModuleTranslation {
name: String::from(ccx.codegen_unit().name()),
symbol_name_hash: ccx.codegen_unit().compute_symbol_name_hash(tcx, &symbol_map),
source: source,
}
})
.collect();
assert_module_sources::assert_module_sources(tcx, &modules);
// Skip crate items and just output metadata in -Z no-trans mode.
if tcx.sess.opts.no_trans {
let linker_info = LinkerInfo::new(&shared_ccx, &[]);
return CrateTranslation {
modules: modules,
metadata_module: metadata_module,
link: link_meta,
metadata: metadata,
reachable: vec![],
no_builtins: no_builtins,
linker_info: linker_info
};
}
// Instantiate translation items without filling out definitions yet...
for ccx in crate_context_list.iter_need_trans() {
let cgu = ccx.codegen_unit();
let trans_items = cgu.items_in_deterministic_order(tcx, &symbol_map);
tcx.dep_graph.with_task(cgu.work_product_dep_node(), || {
for (trans_item, linkage) in trans_items {
trans_item.predefine(&ccx, linkage);
}
});
}
// ... and now that we have everything pre-defined, fill out those definitions.
for ccx in crate_context_list.iter_need_trans() {
let cgu = ccx.codegen_unit();
let trans_items = cgu.items_in_deterministic_order(tcx, &symbol_map);
tcx.dep_graph.with_task(cgu.work_product_dep_node(), || {
for (trans_item, _) in trans_items {
trans_item.define(&ccx);
}
// If this codegen unit contains the main function, also create the
// wrapper here
maybe_create_entry_wrapper(&ccx);
// Run replace-all-uses-with for statics that need it
for &(old_g, new_g) in ccx.statics_to_rauw().borrow().iter() {
unsafe {
let bitcast = llvm::LLVMConstPointerCast(new_g, llvm::LLVMTypeOf(old_g));
llvm::LLVMReplaceAllUsesWith(old_g, bitcast);
llvm::LLVMDeleteGlobal(old_g);
}
}
// Finalize debuginfo
if ccx.sess().opts.debuginfo != NoDebugInfo {
debuginfo::finalize(&ccx);
}
});
}
symbol_names_test::report_symbol_names(&shared_ccx);
if shared_ccx.sess().trans_stats() {
let stats = shared_ccx.stats();
println!("--- trans stats ---");
println!("n_glues_created: {}", stats.n_glues_created.get());
println!("n_null_glues: {}", stats.n_null_glues.get());
println!("n_real_glues: {}", stats.n_real_glues.get());
println!("n_fallback_instantiations: {}", stats.n_fallback_instantiations.get());
println!("n_fns: {}", stats.n_fns.get());
println!("n_monos: {}", stats.n_monos.get());
println!("n_inlines: {}", stats.n_inlines.get());
println!("n_closures: {}", stats.n_closures.get());
println!("fn stats:");
stats.fn_stats.borrow_mut().sort_by(|&(_, insns_a), &(_, insns_b)| {
insns_b.cmp(&insns_a)
});
for tuple in stats.fn_stats.borrow().iter() {
match *tuple {
(ref name, insns) => {
println!("{} insns, {}", insns, *name);
}
}
}
}
if shared_ccx.sess().count_llvm_insns() {
for (k, v) in shared_ccx.stats().llvm_insns.borrow().iter() {
println!("{:7} {}", *v, *k);
}
}
let sess = shared_ccx.sess();
let mut reachable_symbols = shared_ccx.reachable().iter().map(|&id| {
let def_id = shared_ccx.tcx().map.local_def_id(id);
symbol_for_def_id(def_id, &shared_ccx, &symbol_map)
}).collect::<Vec<_>>();
if sess.entry_fn.borrow().is_some() {
reachable_symbols.push("main".to_string());
}
if sess.crate_types.borrow().contains(&config::CrateTypeDylib) {
reachable_symbols.push(shared_ccx.metadata_symbol_name());
}
// For the purposes of LTO or when creating a cdylib, we add to the
// reachable set all of the upstream reachable extern fns. These functions
// are all part of the public ABI of the final product, so we need to
// preserve them.
//
// Note that this happens even if LTO isn't requested or we're not creating
// a cdylib. In those cases, though, we're not even reading the
// `reachable_symbols` list later on so it should be ok.
for cnum in sess.cstore.crates() {
let syms = sess.cstore.reachable_ids(cnum);
reachable_symbols.extend(syms.into_iter().filter(|did| {
sess.cstore.is_extern_item(shared_ccx.tcx(), *did)
}).map(|did| {
symbol_for_def_id(did, &shared_ccx, &symbol_map)
}));
}
time(shared_ccx.sess().time_passes(), "internalize symbols", || {
internalize_symbols(sess,
&crate_context_list,
&symbol_map,
&reachable_symbols.iter()
.map(|s| &s[..])
.collect())
});
if sess.target.target.options.is_like_msvc &&
sess.crate_types.borrow().iter().any(|ct| *ct == config::CrateTypeRlib) {
create_imps(&crate_context_list);
}
let linker_info = LinkerInfo::new(&shared_ccx, &reachable_symbols);
CrateTranslation {
modules: modules,
metadata_module: metadata_module,
link: link_meta,
metadata: metadata,
reachable: reachable_symbols,
no_builtins: no_builtins,
linker_info: linker_info
}
}
/// For each CGU, identify if we can reuse an existing object file (or
/// maybe other context).
fn trans_reuse_previous_work_products(tcx: TyCtxt,
codegen_units: &[CodegenUnit],
symbol_map: &SymbolMap)
-> Vec<Option<WorkProduct>> {
debug!("trans_reuse_previous_work_products()");
codegen_units
.iter()
.map(|cgu| {
let id = cgu.work_product_id();
let hash = cgu.compute_symbol_name_hash(tcx, symbol_map);
debug!("trans_reuse_previous_work_products: id={:?} hash={}", id, hash);
if let Some(work_product) = tcx.dep_graph.previous_work_product(&id) {
if work_product.input_hash == hash {
debug!("trans_reuse_previous_work_products: reusing {:?}", work_product);
return Some(work_product);
} else {
debug!("trans_reuse_previous_work_products: \
not reusing {:?} because hash changed to {:?}",
work_product, hash);
}
}
None
})
.collect()
}
fn collect_and_partition_translation_items<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>)
-> (Vec<CodegenUnit<'tcx>>, SymbolMap<'tcx>) {
let time_passes = scx.sess().time_passes();
let collection_mode = match scx.sess().opts.debugging_opts.print_trans_items {
Some(ref s) => {
let mode_string = s.to_lowercase();
let mode_string = mode_string.trim();
if mode_string == "eager" {
TransItemCollectionMode::Eager
} else {
if mode_string != "lazy" {
let message = format!("Unknown codegen-item collection mode '{}'. \
Falling back to 'lazy' mode.",
mode_string);
scx.sess().warn(&message);
}
TransItemCollectionMode::Lazy
}
}
None => TransItemCollectionMode::Lazy
};
let (items, inlining_map) =
time(time_passes, "translation item collection", || {
collector::collect_crate_translation_items(&scx, collection_mode)
});
let symbol_map = SymbolMap::build(scx, items.iter().cloned());
let strategy = if scx.sess().opts.debugging_opts.incremental.is_some() {
PartitioningStrategy::PerModule
} else {
PartitioningStrategy::FixedUnitCount(scx.sess().opts.cg.codegen_units)
};
let codegen_units = time(time_passes, "codegen unit partitioning", || {
partitioning::partition(scx.tcx(),
items.iter().cloned(),
strategy,
&inlining_map,
scx.reachable())
});
assert!(scx.tcx().sess.opts.cg.codegen_units == codegen_units.len() ||
scx.tcx().sess.opts.debugging_opts.incremental.is_some());
{
let mut ccx_map = scx.translation_items().borrow_mut();
for trans_item in items.iter().cloned() {
ccx_map.insert(trans_item);
}
}
if scx.sess().opts.debugging_opts.print_trans_items.is_some() {
let mut item_to_cgus = HashMap::new();
for cgu in &codegen_units {
for (&trans_item, &linkage) in cgu.items() {
item_to_cgus.entry(trans_item)
.or_insert(Vec::new())
.push((cgu.name().clone(), linkage));
}
}
let mut item_keys: Vec<_> = items
.iter()
.map(|i| {
let mut output = i.to_string(scx.tcx());
output.push_str(" @@");
let mut empty = Vec::new();
let mut cgus = item_to_cgus.get_mut(i).unwrap_or(&mut empty);
cgus.as_mut_slice().sort_by_key(|&(ref name, _)| name.clone());
cgus.dedup();
for &(ref cgu_name, linkage) in cgus.iter() {
output.push_str(" ");
output.push_str(&cgu_name[..]);
let linkage_abbrev = match linkage {
llvm::ExternalLinkage => "External",
llvm::AvailableExternallyLinkage => "Available",
llvm::LinkOnceAnyLinkage => "OnceAny",
llvm::LinkOnceODRLinkage => "OnceODR",
llvm::WeakAnyLinkage => "WeakAny",
llvm::WeakODRLinkage => "WeakODR",
llvm::AppendingLinkage => "Appending",
llvm::InternalLinkage => "Internal",
llvm::PrivateLinkage => "Private",
llvm::ExternalWeakLinkage => "ExternalWeak",
llvm::CommonLinkage => "Common",
};
output.push_str("[");
output.push_str(linkage_abbrev);
output.push_str("]");
}
output
})
.collect();
item_keys.sort();
for item in item_keys {
println!("TRANS_ITEM {}", item);
}
}
(codegen_units, symbol_map)
}
fn symbol_for_def_id<'a, 'tcx>(def_id: DefId,
scx: &SharedCrateContext<'a, 'tcx>,
symbol_map: &SymbolMap<'tcx>)
-> String {
// Just try to look things up in the symbol map. If nothing's there, we
// recompute.
if let Some(node_id) = scx.tcx().map.as_local_node_id(def_id) {
if let Some(sym) = symbol_map.get(TransItem::Static(node_id)) {
return sym.to_owned();
}
}
let instance = Instance::mono(scx, def_id);
symbol_map.get(TransItem::Fn(instance))
.map(str::to_owned)
.unwrap_or_else(|| instance.symbol_name(scx))
}