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54c2a1e1ce
rust/src/librustc/middle/trans/base.rs
Alex Crichton 54c2a1e1ce rustc: Move the AST from @T to Gc<T>
2014-06-11 09:51:37 -07:00

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// 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.
// trans.rs: 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,
// trans_impl, 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::t 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::t`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 back::link::{mangle_exported_name};
use back::{link, abi};
use driver::config;
use driver::config::{NoDebugInfo, FullDebugInfo};
use driver::session::Session;
use driver::driver::OutputFilenames;
use driver::driver::{CrateAnalysis, CrateTranslation};
use lib::llvm::{ModuleRef, ValueRef, BasicBlockRef};
use lib::llvm::{llvm, Vector};
use lib;
use metadata::{csearch, encoder};
use middle::lint;
use middle::astencode;
use middle::lang_items::{LangItem, ExchangeMallocFnLangItem, StartFnLangItem};
use middle::weak_lang_items;
use middle::subst;
use middle::subst::Subst;
use middle::trans::_match;
use middle::trans::adt;
use middle::trans::build::*;
use middle::trans::builder::{Builder, noname};
use middle::trans::callee;
use middle::trans::cleanup;
use middle::trans::cleanup::CleanupMethods;
use middle::trans::common::*;
use middle::trans::consts;
use middle::trans::controlflow;
use middle::trans::datum;
// use middle::trans::datum::{Datum, Lvalue, Rvalue, ByRef, ByValue};
use middle::trans::debuginfo;
use middle::trans::expr;
use middle::trans::foreign;
use middle::trans::glue;
use middle::trans::inline;
use middle::trans::machine;
use middle::trans::machine::{llalign_of_min, llsize_of, llsize_of_real};
use middle::trans::meth;
use middle::trans::monomorphize;
use middle::trans::tvec;
use middle::trans::type_::Type;
use middle::trans::type_of;
use middle::trans::type_of::*;
use middle::trans::value::Value;
use middle::ty;
use middle::typeck;
use util::common::indenter;
use util::ppaux::{Repr, ty_to_str};
use util::sha2::Sha256;
use util::nodemap::NodeMap;
use arena::TypedArena;
use libc::{c_uint, uint64_t};
use std::c_str::ToCStr;
use std::cell::{Cell, RefCell};
use std::rc::Rc;
use std::{i8, i16, i32, i64};
use std::gc::Gc;
use syntax::abi::{X86, X86_64, Arm, Mips, Rust, RustIntrinsic};
use syntax::ast_util::{local_def, is_local};
use syntax::attr::AttrMetaMethods;
use syntax::attr;
use syntax::codemap::Span;
use syntax::parse::token::InternedString;
use syntax::visit::Visitor;
use syntax::visit;
use syntax::{ast, ast_util, ast_map};
use time;
local_data_key!(task_local_insn_key: RefCell<Vec<&'static str>>)
pub fn with_insn_ctxt(blk: |&[&'static str]|) {
match task_local_insn_key.get() {
Some(ctx) => blk(ctx.borrow().as_slice()),
None => ()
}
}
pub fn init_insn_ctxt() {
task_local_insn_key.replace(Some(RefCell::new(Vec::new())));
}
pub struct _InsnCtxt {
_cannot_construct_outside_of_this_module: ()
}
#[unsafe_destructor]
impl Drop for _InsnCtxt {
fn drop(&mut self) {
match task_local_insn_key.get() {
Some(ctx) => { ctx.borrow_mut().pop(); }
None => {}
}
}
}
pub fn push_ctxt(s: &'static str) -> _InsnCtxt {
debug!("new InsnCtxt: {}", s);
match task_local_insn_key.get() {
Some(ctx) => ctx.borrow_mut().push(s),
None => {}
}
_InsnCtxt { _cannot_construct_outside_of_this_module: () }
}
pub struct StatRecorder<'a> {
ccx: &'a CrateContext,
name: Option<String>,
start: u64,
istart: uint,
}
impl<'a> StatRecorder<'a> {
pub fn new(ccx: &'a CrateContext, name: String) -> StatRecorder<'a> {
let start = if ccx.sess().trans_stats() {
time::precise_time_ns()
} else {
0
};
let istart = ccx.stats.n_llvm_insns.get();
StatRecorder {
ccx: ccx,
name: Some(name),
start: start,
istart: istart,
}
}
}
#[unsafe_destructor]
impl<'a> Drop for StatRecorder<'a> {
fn drop(&mut self) {
if self.ccx.sess().trans_stats() {
let end = time::precise_time_ns();
let elapsed = ((end - self.start) / 1_000_000) as uint;
let iend = self.ccx.stats.n_llvm_insns.get();
self.ccx.stats.fn_stats.borrow_mut().push((self.name.take_unwrap(),
elapsed,
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);
}
}
}
// only use this for foreign function ABIs and glue, use `decl_rust_fn` for Rust functions
fn decl_fn(llmod: ModuleRef, name: &str, cc: lib::llvm::CallConv,
ty: Type, output: ty::t) -> ValueRef {
let llfn: ValueRef = name.with_c_str(|buf| {
unsafe {
llvm::LLVMGetOrInsertFunction(llmod, buf, ty.to_ref())
}
});
match ty::get(output).sty {
// functions returning bottom may unwind, but can never return normally
ty::ty_bot => {
unsafe {
llvm::LLVMAddFunctionAttribute(llfn,
lib::llvm::FunctionIndex as c_uint,
lib::llvm::NoReturnAttribute as uint64_t)
}
}
_ => {}
}
lib::llvm::SetFunctionCallConv(llfn, cc);
// Function addresses in Rust are never significant, allowing functions to be merged.
lib::llvm::SetUnnamedAddr(llfn, true);
set_split_stack(llfn);
llfn
}
// only use this for foreign function ABIs and glue, use `decl_rust_fn` for Rust functions
pub fn decl_cdecl_fn(llmod: ModuleRef,
name: &str,
ty: Type,
output: ty::t) -> ValueRef {
decl_fn(llmod, name, lib::llvm::CCallConv, ty, output)
}
// only use this for foreign function ABIs and glue, use `get_extern_rust_fn` for Rust functions
pub fn get_extern_fn(ccx: &CrateContext,
externs: &mut ExternMap,
name: &str,
cc: lib::llvm::CallConv,
ty: Type,
output: ty::t)
-> ValueRef {
match externs.find_equiv(&name) {
Some(n) => return *n,
None => {}
}
let f = decl_fn(ccx.llmod, name, cc, ty, output);
externs.insert(name.to_string(), f);
f
}
fn get_extern_rust_fn(ccx: &CrateContext, fn_ty: ty::t, name: &str, did: ast::DefId) -> ValueRef {
match ccx.externs.borrow().find_equiv(&name) {
Some(n) => return *n,
None => ()
}
let f = decl_rust_fn(ccx, fn_ty, name);
csearch::get_item_attrs(&ccx.sess().cstore, did, |attrs| {
set_llvm_fn_attrs(attrs.as_slice(), f)
});
ccx.externs.borrow_mut().insert(name.to_string(), f);
f
}
pub fn decl_rust_fn(ccx: &CrateContext, fn_ty: ty::t, name: &str) -> ValueRef {
let (inputs, output, has_env) = match ty::get(fn_ty).sty {
ty::ty_bare_fn(ref f) => (f.sig.inputs.clone(), f.sig.output, false),
ty::ty_closure(ref f) => (f.sig.inputs.clone(), f.sig.output, true),
_ => fail!("expected closure or fn")
};
let llfty = type_of_rust_fn(ccx, has_env, inputs.as_slice(), output);
let llfn = decl_fn(ccx.llmod, name, lib::llvm::CCallConv, llfty, output);
let attrs = get_fn_llvm_attributes(ccx, fn_ty);
for &(idx, attr) in attrs.iter() {
unsafe {
llvm::LLVMAddFunctionAttribute(llfn, idx as c_uint, attr);
}
}
llfn
}
pub fn decl_internal_rust_fn(ccx: &CrateContext, fn_ty: ty::t, name: &str) -> ValueRef {
let llfn = decl_rust_fn(ccx, fn_ty, name);
lib::llvm::SetLinkage(llfn, lib::llvm::InternalLinkage);
llfn
}
pub fn get_extern_const(externs: &mut ExternMap, llmod: ModuleRef,
name: &str, ty: Type) -> ValueRef {
match externs.find_equiv(&name) {
Some(n) => return *n,
None => ()
}
unsafe {
let c = name.with_c_str(|buf| {
llvm::LLVMAddGlobal(llmod, ty.to_ref(), buf)
});
externs.insert(name.to_string(), c);
return c;
}
}
// Returns a pointer to the body for the box. The box may be an opaque
// box. The result will be casted to the type of body_t, if it is statically
// known.
pub fn at_box_body(bcx: &Block, body_t: ty::t, boxptr: ValueRef) -> ValueRef {
let _icx = push_ctxt("at_box_body");
let ccx = bcx.ccx();
let ty = Type::at_box(ccx, type_of(ccx, body_t));
let boxptr = PointerCast(bcx, boxptr, ty.ptr_to());
GEPi(bcx, boxptr, [0u, abi::box_field_body])
}
fn require_alloc_fn(bcx: &Block, info_ty: ty::t, it: LangItem) -> ast::DefId {
match bcx.tcx().lang_items.require(it) {
Ok(id) => id,
Err(s) => {
bcx.sess().fatal(format!("allocation of `{}` {}",
bcx.ty_to_str(info_ty),
s).as_slice());
}
}
}
// 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<'a>(bcx: &'a Block<'a>,
ptr_ty: ty::t,
size: ValueRef,
align: ValueRef)
-> Result<'a> {
let _icx = push_ctxt("malloc_raw_exchange");
let ccx = bcx.ccx();
// Allocate space:
let r = callee::trans_lang_call(bcx,
require_alloc_fn(bcx, ptr_ty, ExchangeMallocFnLangItem),
[size, align],
None);
let llty_ptr = type_of::type_of(ccx, ptr_ty);
Result::new(r.bcx, PointerCast(r.bcx, r.val, llty_ptr))
}
pub fn malloc_raw_dyn_managed<'a>(
bcx: &'a Block<'a>,
t: ty::t,
alloc_fn: LangItem,
size: ValueRef)
-> Result<'a> {
let _icx = push_ctxt("malloc_raw_managed");
let ccx = bcx.ccx();
let langcall = require_alloc_fn(bcx, t, alloc_fn);
// Grab the TypeRef type of box_ptr_ty.
let box_ptr_ty = ty::mk_box(bcx.tcx(), t);
let llty = type_of(ccx, box_ptr_ty);
let llalign = C_uint(ccx, llalign_of_min(ccx, llty) as uint);
// Allocate space:
let drop_glue = glue::get_drop_glue(ccx, t);
let r = callee::trans_lang_call(
bcx,
langcall,
[
PointerCast(bcx, drop_glue, Type::glue_fn(ccx, Type::i8p(ccx)).ptr_to()),
size,
llalign
],
None);
Result::new(r.bcx, PointerCast(r.bcx, r.val, llty))
}
// Type descriptor and type glue stuff
pub fn get_tydesc(ccx: &CrateContext, t: ty::t) -> Rc<tydesc_info> {
match ccx.tydescs.borrow().find(&t) {
Some(inf) => return inf.clone(),
_ => { }
}
ccx.stats.n_static_tydescs.set(ccx.stats.n_static_tydescs.get() + 1u);
let inf = Rc::new(glue::declare_tydesc(ccx, t));
ccx.tydescs.borrow_mut().insert(t, inf.clone());
inf
}
#[allow(dead_code)] // useful
pub fn set_optimize_for_size(f: ValueRef) {
lib::llvm::SetFunctionAttribute(f, lib::llvm::OptimizeForSizeAttribute)
}
pub fn set_no_inline(f: ValueRef) {
lib::llvm::SetFunctionAttribute(f, lib::llvm::NoInlineAttribute)
}
#[allow(dead_code)] // useful
pub fn set_no_unwind(f: ValueRef) {
lib::llvm::SetFunctionAttribute(f, lib::llvm::NoUnwindAttribute)
}
// Tell LLVM to emit the information necessary to unwind the stack for the
// function f.
pub fn set_uwtable(f: ValueRef) {
lib::llvm::SetFunctionAttribute(f, lib::llvm::UWTableAttribute)
}
pub fn set_inline_hint(f: ValueRef) {
lib::llvm::SetFunctionAttribute(f, lib::llvm::InlineHintAttribute)
}
pub fn set_llvm_fn_attrs(attrs: &[ast::Attribute], llfn: ValueRef) {
use syntax::attr::*;
// Set the inline hint if there is one
match find_inline_attr(attrs) {
InlineHint => set_inline_hint(llfn),
InlineAlways => set_always_inline(llfn),
InlineNever => set_no_inline(llfn),
InlineNone => { /* fallthrough */ }
}
// Add the no-split-stack attribute if requested
if contains_name(attrs, "no_split_stack") {
unset_split_stack(llfn);
}
if contains_name(attrs, "cold") {
unsafe {
llvm::LLVMAddFunctionAttribute(llfn,
lib::llvm::FunctionIndex as c_uint,
lib::llvm::ColdAttribute as uint64_t)
}
}
}
pub fn set_always_inline(f: ValueRef) {
lib::llvm::SetFunctionAttribute(f, lib::llvm::AlwaysInlineAttribute)
}
pub fn set_split_stack(f: ValueRef) {
"split-stack".with_c_str(|buf| {
unsafe { llvm::LLVMAddFunctionAttrString(f, lib::llvm::FunctionIndex as c_uint, buf); }
})
}
pub fn unset_split_stack(f: ValueRef) {
"split-stack".with_c_str(|buf| {
unsafe { llvm::LLVMRemoveFunctionAttrString(f, lib::llvm::FunctionIndex as c_uint, buf); }
})
}
// Double-check that we never ask LLVM to declare the same symbol twice. It
// silently mangles such symbols, breaking our linkage model.
pub fn note_unique_llvm_symbol(ccx: &CrateContext, sym: String) {
if ccx.all_llvm_symbols.borrow().contains(&sym) {
ccx.sess().bug(format!("duplicate LLVM symbol: {}", sym).as_slice());
}
ccx.all_llvm_symbols.borrow_mut().insert(sym);
}
pub fn get_res_dtor(ccx: &CrateContext,
did: ast::DefId,
t: ty::t,
parent_id: ast::DefId,
substs: &subst::Substs)
-> ValueRef {
let _icx = push_ctxt("trans_res_dtor");
let did = if did.krate != ast::LOCAL_CRATE {
inline::maybe_instantiate_inline(ccx, did)
} else {
did
};
if !substs.tps.is_empty() || !substs.self_ty.is_none() {
assert_eq!(did.krate, ast::LOCAL_CRATE);
let vtables = typeck::check::vtable::trans_resolve_method(ccx.tcx(), did.node, substs);
let (val, _) = monomorphize::monomorphic_fn(ccx, did, substs, vtables, None, None);
val
} else if did.krate == ast::LOCAL_CRATE {
get_item_val(ccx, did.node)
} else {
let tcx = ccx.tcx();
let name = csearch::get_symbol(&ccx.sess().cstore, did);
let class_ty = ty::lookup_item_type(tcx, parent_id).ty.subst(tcx, substs);
let llty = type_of_dtor(ccx, class_ty);
let dtor_ty = ty::mk_ctor_fn(ccx.tcx(), ast::DUMMY_NODE_ID,
[glue::get_drop_glue_type(ccx, t)], ty::mk_nil());
get_extern_fn(ccx,
&mut *ccx.externs.borrow_mut(),
name.as_slice(),
lib::llvm::CCallConv,
llty,
dtor_ty)
}
}
// Structural comparison: a rather involved form of glue.
pub fn maybe_name_value(cx: &CrateContext, v: ValueRef, s: &str) {
if cx.sess().opts.cg.save_temps {
s.with_c_str(|buf| {
unsafe {
llvm::LLVMSetValueName(v, buf)
}
})
}
}
// Used only for creating scalar comparison glue.
pub enum scalar_type { nil_type, signed_int, unsigned_int, floating_point, }
// NB: This produces an i1, not a Rust bool (i8).
pub fn compare_scalar_types<'a>(
cx: &'a Block<'a>,
lhs: ValueRef,
rhs: ValueRef,
t: ty::t,
op: ast::BinOp)
-> Result<'a> {
let f = |a| Result::new(cx, compare_scalar_values(cx, lhs, rhs, a, op));
match ty::get(t).sty {
ty::ty_nil => f(nil_type),
ty::ty_bool | ty::ty_ptr(_) |
ty::ty_uint(_) | ty::ty_char => f(unsigned_int),
ty::ty_int(_) => f(signed_int),
ty::ty_float(_) => f(floating_point),
// Should never get here, because t is scalar.
_ => cx.sess().bug("non-scalar type passed to compare_scalar_types")
}
}
// A helper function to do the actual comparison of scalar values.
pub fn compare_scalar_values<'a>(
cx: &'a Block<'a>,
lhs: ValueRef,
rhs: ValueRef,
nt: scalar_type,
op: ast::BinOp)
-> ValueRef {
let _icx = push_ctxt("compare_scalar_values");
fn die(cx: &Block) -> ! {
cx.sess().bug("compare_scalar_values: must be a comparison operator");
}
match nt {
nil_type => {
// We don't need to do actual comparisons for nil.
// () == () holds but () < () does not.
match op {
ast::BiEq | ast::BiLe | ast::BiGe => return C_i1(cx.ccx(), true),
ast::BiNe | ast::BiLt | ast::BiGt => return C_i1(cx.ccx(), false),
// refinements would be nice
_ => die(cx)
}
}
floating_point => {
let cmp = match op {
ast::BiEq => lib::llvm::RealOEQ,
ast::BiNe => lib::llvm::RealUNE,
ast::BiLt => lib::llvm::RealOLT,
ast::BiLe => lib::llvm::RealOLE,
ast::BiGt => lib::llvm::RealOGT,
ast::BiGe => lib::llvm::RealOGE,
_ => die(cx)
};
return FCmp(cx, cmp, lhs, rhs);
}
signed_int => {
let cmp = match op {
ast::BiEq => lib::llvm::IntEQ,
ast::BiNe => lib::llvm::IntNE,
ast::BiLt => lib::llvm::IntSLT,
ast::BiLe => lib::llvm::IntSLE,
ast::BiGt => lib::llvm::IntSGT,
ast::BiGe => lib::llvm::IntSGE,
_ => die(cx)
};
return ICmp(cx, cmp, lhs, rhs);
}
unsigned_int => {
let cmp = match op {
ast::BiEq => lib::llvm::IntEQ,
ast::BiNe => lib::llvm::IntNE,
ast::BiLt => lib::llvm::IntULT,
ast::BiLe => lib::llvm::IntULE,
ast::BiGt => lib::llvm::IntUGT,
ast::BiGe => lib::llvm::IntUGE,
_ => die(cx)
};
return ICmp(cx, cmp, lhs, rhs);
}
}
}
pub fn compare_simd_types(
cx: &Block,
lhs: ValueRef,
rhs: ValueRef,
t: ty::t,
size: uint,
op: ast::BinOp)
-> ValueRef {
match ty::get(t).sty {
ty::ty_float(_) => {
// The comparison operators for floating point vectors are challenging.
// LLVM outputs a `< size x i1 >`, but if we perform a sign extension
// then bitcast to a floating point vector, the result will be `-NaN`
// for each truth value. Because of this they are unsupported.
cx.sess().bug("compare_simd_types: comparison operators \
not supported for floating point SIMD types")
},
ty::ty_uint(_) | ty::ty_int(_) => {
let cmp = match op {
ast::BiEq => lib::llvm::IntEQ,
ast::BiNe => lib::llvm::IntNE,
ast::BiLt => lib::llvm::IntSLT,
ast::BiLe => lib::llvm::IntSLE,
ast::BiGt => lib::llvm::IntSGT,
ast::BiGe => lib::llvm::IntSGE,
_ => cx.sess().bug("compare_simd_types: must be a comparison operator"),
};
let return_ty = Type::vector(&type_of(cx.ccx(), t), size as u64);
// 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(cx, ICmp(cx, cmp, lhs, rhs), return_ty)
},
_ => cx.sess().bug("compare_simd_types: invalid SIMD type"),
}
}
pub type val_and_ty_fn<'r,'b> =
|&'b Block<'b>, ValueRef, ty::t|: 'r -> &'b Block<'b>;
// Iterates through the elements of a structural type.
pub fn iter_structural_ty<'r,
'b>(
cx: &'b Block<'b>,
av: ValueRef,
t: ty::t,
f: val_and_ty_fn<'r,'b>)
-> &'b Block<'b> {
let _icx = push_ctxt("iter_structural_ty");
fn iter_variant<'r,
'b>(
cx: &'b Block<'b>,
repr: &adt::Repr,
av: ValueRef,
variant: &ty::VariantInfo,
substs: &subst::Substs,
f: val_and_ty_fn<'r,'b>)
-> &'b Block<'b> {
let _icx = push_ctxt("iter_variant");
let tcx = cx.tcx();
let mut cx = cx;
for (i, &arg) in variant.args.iter().enumerate() {
cx = f(cx,
adt::trans_field_ptr(cx, repr, av, variant.disr_val, i),
arg.subst(tcx, substs));
}
return cx;
}
let mut cx = cx;
match ty::get(t).sty {
ty::ty_struct(..) => {
let repr = adt::represent_type(cx.ccx(), t);
expr::with_field_tys(cx.tcx(), t, None, |discr, field_tys| {
for (i, field_ty) in field_tys.iter().enumerate() {
let llfld_a = adt::trans_field_ptr(cx, &*repr, av, discr, i);
cx = f(cx, llfld_a, field_ty.mt.ty);
}
})
}
ty::ty_vec(_, Some(n)) => {
let unit_ty = ty::sequence_element_type(cx.tcx(), t);
let (base, len) = tvec::get_fixed_base_and_byte_len(cx, av, unit_ty, n);
cx = tvec::iter_vec_raw(cx, base, unit_ty, len, f);
}
ty::ty_tup(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, av, 0, i);
cx = f(cx, llfld_a, *arg);
}
}
ty::ty_enum(tid, ref substs) => {
let fcx = cx.fcx;
let ccx = fcx.ccx;
let repr = adt::represent_type(ccx, t);
let variants = ty::enum_variants(ccx.tcx(), tid);
let n_variants = (*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) {
(_match::single, None) => {
cx = iter_variant(cx, &*repr, av, &**variants.get(0),
substs, f);
}
(_match::switch, Some(lldiscrim_a)) => {
cx = f(cx, lldiscrim_a, ty::mk_int());
let unr_cx = fcx.new_temp_block("enum-iter-unr");
Unreachable(unr_cx);
let llswitch = Switch(cx, lldiscrim_a, unr_cx.llbb,
n_variants);
let next_cx = fcx.new_temp_block("enum-iter-next");
for variant in (*variants).iter() {
let variant_cx =
fcx.new_temp_block(
format!("enum-iter-variant-{}",
variant.disr_val.to_str().as_slice())
.as_slice());
match adt::trans_case(cx, &*repr, variant.disr_val) {
_match::single_result(r) => {
AddCase(llswitch, r.val, variant_cx.llbb)
}
_ => ccx.sess().unimpl("value from adt::trans_case \
in iter_structural_ty")
}
let variant_cx =
iter_variant(variant_cx,
&*repr,
av,
&**variant,
substs,
|x,y,z| f(x,y,z));
Br(variant_cx, next_cx.llbb);
}
cx = next_cx;
}
_ => ccx.sess().unimpl("value from adt::trans_switch \
in iter_structural_ty")
}
}
_ => cx.sess().unimpl("type in iter_structural_ty")
}
return cx;
}
pub fn cast_shift_expr_rhs<'a>(
cx: &'a Block<'a>,
op: ast::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: ast::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()) })
}
pub fn cast_shift_rhs(op: ast::BinOp,
lhs: ValueRef,
rhs: ValueRef,
trunc: |ValueRef, Type| -> ValueRef,
zext: |ValueRef, Type| -> ValueRef)
-> ValueRef {
// Shifts may have any size int on the rhs
unsafe {
if ast_util::is_shift_binop(op) {
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 = llvm::LLVMGetIntTypeWidth(rhs_llty.to_ref());
let lhs_sz = llvm::LLVMGetIntTypeWidth(lhs_llty.to_ref());
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 fail_if_zero_or_overflows<'a>(
cx: &'a Block<'a>,
span: Span,
divrem: ast::BinOp,
lhs: ValueRef,
rhs: ValueRef,
rhs_t: ty::t)
-> &'a Block<'a> {
let (zero_text, overflow_text) = if divrem == ast::BiDiv {
("attempted to divide by zero",
"attempted to divide with overflow")
} else {
("attempted remainder with a divisor of zero",
"attempted remainder with overflow")
};
let (is_zero, is_signed) = match ty::get(rhs_t).sty {
ty::ty_int(t) => {
let zero = C_integral(Type::int_from_ty(cx.ccx(), t), 0u64, false);
(ICmp(cx, lib::llvm::IntEQ, rhs, zero), true)
}
ty::ty_uint(t) => {
let zero = C_integral(Type::uint_from_ty(cx.ccx(), t), 0u64, false);
(ICmp(cx, lib::llvm::IntEQ, rhs, zero), false)
}
_ => {
cx.sess().bug(format!("fail-if-zero on unexpected type: {}",
ty_to_str(cx.tcx(), rhs_t)).as_slice());
}
};
let bcx = with_cond(cx, is_zero, |bcx| {
controlflow::trans_fail(bcx, span, InternedString::new(zero_text))
});
// 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) = match ty::get(rhs_t).sty {
ty::ty_int(t) => {
let llty = Type::int_from_ty(cx.ccx(), t);
let min = match t {
ast::TyI if llty == Type::i32(cx.ccx()) => i32::MIN as u64,
ast::TyI => i64::MIN as u64,
ast::TyI8 => i8::MIN as u64,
ast::TyI16 => i16::MIN as u64,
ast::TyI32 => i32::MIN as u64,
ast::TyI64 => i64::MIN as u64,
};
(llty, min)
}
_ => unreachable!(),
};
let minus_one = ICmp(bcx, lib::llvm::IntEQ, rhs,
C_integral(llty, -1, false));
with_cond(bcx, minus_one, |bcx| {
let is_min = ICmp(bcx, lib::llvm::IntEQ, lhs,
C_integral(llty, min, true));
with_cond(bcx, is_min, |bcx| {
controlflow::trans_fail(bcx, span,
InternedString::new(overflow_text))
})
})
} else {
bcx
}
}
pub fn trans_external_path(ccx: &CrateContext, did: ast::DefId, t: ty::t) -> ValueRef {
let name = csearch::get_symbol(&ccx.sess().cstore, did);
match ty::get(t).sty {
ty::ty_bare_fn(ref fn_ty) => {
match fn_ty.abi.for_target(ccx.sess().targ_cfg.os,
ccx.sess().targ_cfg.arch) {
Some(Rust) | Some(RustIntrinsic) => {
get_extern_rust_fn(ccx, t, name.as_slice(), did)
}
Some(..) | None => {
foreign::register_foreign_item_fn(ccx, fn_ty.abi, t,
name.as_slice(), None)
}
}
}
ty::ty_closure(_) => {
get_extern_rust_fn(ccx, t, name.as_slice(), did)
}
_ => {
let llty = type_of(ccx, t);
get_extern_const(&mut *ccx.externs.borrow_mut(),
ccx.llmod,
name.as_slice(),
llty)
}
}
}
pub fn invoke<'a>(
bcx: &'a Block<'a>,
llfn: ValueRef,
llargs: Vec<ValueRef> ,
fn_ty: ty::t,
call_info: Option<NodeInfo>)
-> (ValueRef, &'a Block<'a>) {
let _icx = push_ctxt("invoke_");
if bcx.unreachable.get() {
return (C_null(Type::i8(bcx.ccx())), bcx);
}
let attributes = get_fn_llvm_attributes(bcx.ccx(), fn_ty);
match bcx.opt_node_id {
None => {
debug!("invoke at ???");
}
Some(id) => {
debug!("invoke at {}", bcx.tcx().map.node_to_str(id));
}
}
if need_invoke(bcx) {
debug!("invoking {} at {}", llfn, bcx.llbb);
for &llarg in llargs.iter() {
debug!("arg: {}", llarg);
}
let normal_bcx = bcx.fcx.new_temp_block("normal-return");
let landing_pad = bcx.fcx.get_landing_pad();
match call_info {
Some(info) => debuginfo::set_source_location(bcx.fcx, info.id, info.span),
None => debuginfo::clear_source_location(bcx.fcx)
};
let llresult = Invoke(bcx,
llfn,
llargs.as_slice(),
normal_bcx.llbb,
landing_pad,
attributes.as_slice());
return (llresult, normal_bcx);
} else {
debug!("calling {} at {}", llfn, bcx.llbb);
for &llarg in llargs.iter() {
debug!("arg: {}", llarg);
}
match call_info {
Some(info) => debuginfo::set_source_location(bcx.fcx, info.id, info.span),
None => debuginfo::clear_source_location(bcx.fcx)
};
let llresult = Call(bcx, llfn, llargs.as_slice(), attributes.as_slice());
return (llresult, bcx);
}
}
pub fn need_invoke(bcx: &Block) -> bool {
if bcx.sess().no_landing_pads() {
return false;
}
// Avoid using invoke if we are already inside a landing pad.
if bcx.is_lpad {
return false;
}
bcx.fcx.needs_invoke()
}
pub fn load_if_immediate(cx: &Block, v: ValueRef, t: ty::t) -> ValueRef {
let _icx = push_ctxt("load_if_immediate");
if type_is_immediate(cx.ccx(), t) { return Load(cx, v); }
return v;
}
pub fn ignore_lhs(_bcx: &Block, local: &ast::Local) -> bool {
match local.pat.node {
ast::PatWild => true, _ => false
}
}
pub fn init_local<'a>(bcx: &'a Block<'a>, local: &ast::Local)
-> &'a Block<'a> {
debug!("init_local(bcx={}, local.id={:?})",
bcx.to_str(), local.id);
let _indenter = indenter();
let _icx = push_ctxt("init_local");
if ignore_lhs(bcx, local) {
// Handle let _ = e; just like e;
match local.init {
Some(ref init) => {
return controlflow::trans_stmt_semi(bcx, &**init)
}
None => { return bcx; }
}
}
_match::store_local(bcx, local)
}
pub fn raw_block<'a>(
fcx: &'a FunctionContext<'a>,
is_lpad: bool,
llbb: BasicBlockRef)
-> &'a Block<'a> {
Block::new(llbb, is_lpad, None, fcx)
}
pub fn with_cond<'a>(
bcx: &'a Block<'a>,
val: ValueRef,
f: |&'a Block<'a>| -> &'a Block<'a>)
-> &'a Block<'a> {
let _icx = push_ctxt("with_cond");
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);
let after_cx = f(cond_cx);
if !after_cx.terminated.get() {
Br(after_cx, next_cx.llbb);
}
next_cx
}
pub fn call_memcpy(cx: &Block, dst: ValueRef, src: ValueRef, n_bytes: ValueRef, align: u32) {
let _icx = push_ctxt("call_memcpy");
let ccx = cx.ccx();
let key = match ccx.sess().targ_cfg.arch {
X86 | Arm | Mips => "llvm.memcpy.p0i8.p0i8.i32",
X86_64 => "llvm.memcpy.p0i8.p0i8.i64"
};
let memcpy = ccx.get_intrinsic(&key);
let src_ptr = PointerCast(cx, src, Type::i8p(ccx));
let dst_ptr = PointerCast(cx, dst, Type::i8p(ccx));
let size = IntCast(cx, n_bytes, ccx.int_type);
let align = C_i32(ccx, align as i32);
let volatile = C_i1(ccx, false);
Call(cx, memcpy, [dst_ptr, src_ptr, size, align, volatile], []);
}
pub fn memcpy_ty(bcx: &Block, dst: ValueRef, src: ValueRef, t: ty::t) {
let _icx = push_ctxt("memcpy_ty");
let ccx = bcx.ccx();
if ty::type_is_structural(t) {
let llty = type_of::type_of(ccx, t);
let llsz = llsize_of(ccx, llty);
let llalign = llalign_of_min(ccx, llty);
call_memcpy(bcx, dst, src, llsz, llalign as u32);
} else {
Store(bcx, Load(bcx, src), dst);
}
}
pub fn zero_mem(cx: &Block, llptr: ValueRef, t: ty::t) {
if cx.unreachable.get() { return; }
let _icx = push_ctxt("zero_mem");
let bcx = cx;
let ccx = cx.ccx();
let llty = type_of::type_of(ccx, t);
memzero(&B(bcx), llptr, llty);
}
// Always use this function instead of storing a zero constant to the memory
// in question. 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 memzero(b: &Builder, llptr: ValueRef, ty: Type) {
let _icx = push_ctxt("memzero");
let ccx = b.ccx;
let intrinsic_key = match ccx.sess().targ_cfg.arch {
X86 | Arm | Mips => "llvm.memset.p0i8.i32",
X86_64 => "llvm.memset.p0i8.i64"
};
let llintrinsicfn = ccx.get_intrinsic(&intrinsic_key);
let llptr = b.pointercast(llptr, Type::i8(ccx).ptr_to());
let llzeroval = C_u8(ccx, 0);
let size = machine::llsize_of(ccx, ty);
let align = C_i32(ccx, llalign_of_min(ccx, ty) as i32);
let volatile = C_i1(ccx, false);
b.call(llintrinsicfn, [llptr, llzeroval, size, align, volatile], []);
}
pub fn alloc_ty(bcx: &Block, t: ty::t, name: &str) -> ValueRef {
let _icx = push_ctxt("alloc_ty");
let ccx = bcx.ccx();
let ty = type_of::type_of(ccx, t);
assert!(!ty::type_has_params(t));
let val = alloca(bcx, ty, name);
return val;
}
pub fn alloca(cx: &Block, ty: Type, name: &str) -> ValueRef {
alloca_maybe_zeroed(cx, ty, name, false)
}
pub fn alloca_maybe_zeroed(cx: &Block, ty: Type, name: &str, zero: bool) -> ValueRef {
let _icx = push_ctxt("alloca");
if cx.unreachable.get() {
unsafe {
return llvm::LLVMGetUndef(ty.ptr_to().to_ref());
}
}
debuginfo::clear_source_location(cx.fcx);
let p = Alloca(cx, ty, name);
if zero {
let b = cx.fcx.ccx.builder();
b.position_before(cx.fcx.alloca_insert_pt.get().unwrap());
memzero(&b, p, ty);
}
p
}
pub fn arrayalloca(cx: &Block, ty: Type, v: ValueRef) -> ValueRef {
let _icx = push_ctxt("arrayalloca");
if cx.unreachable.get() {
unsafe {
return llvm::LLVMGetUndef(ty.to_ref());
}
}
debuginfo::clear_source_location(cx.fcx);
return ArrayAlloca(cx, ty, v);
}
// Creates and returns space for, or returns the argument representing, the
// slot where the return value of the function must go.
pub fn make_return_pointer(fcx: &FunctionContext, output_type: ty::t)
-> ValueRef {
unsafe {
if type_of::return_uses_outptr(fcx.ccx, output_type) {
llvm::LLVMGetParam(fcx.llfn, 0)
} else {
let lloutputtype = type_of::type_of(fcx.ccx, output_type);
let bcx = fcx.entry_bcx.borrow().clone().unwrap();
Alloca(bcx, lloutputtype, "__make_return_pointer")
}
}
}
// NB: must keep 4 fns in sync:
//
// - type_of_fn
// - create_datums_for_fn_args.
// - new_fn_ctxt
// - trans_args
//
// Be warned! You must call `init_function` before doing anything with the
// returned function context.
pub fn new_fn_ctxt<'a>(ccx: &'a CrateContext,
llfndecl: ValueRef,
id: ast::NodeId,
has_env: bool,
output_type: ty::t,
param_substs: &'a param_substs,
sp: Option<Span>,
block_arena: &'a TypedArena<Block<'a>>)
-> FunctionContext<'a> {
param_substs.validate();
debug!("new_fn_ctxt(path={}, id={}, param_substs={})",
if id == -1 {
"".to_string()
} else {
ccx.tcx.map.path_to_str(id).to_string()
},
id, param_substs.repr(ccx.tcx()));
let substd_output_type = output_type.substp(ccx.tcx(), param_substs);
let uses_outptr = type_of::return_uses_outptr(ccx, substd_output_type);
let debug_context = debuginfo::create_function_debug_context(ccx, id, param_substs, llfndecl);
let mut fcx = FunctionContext {
llfn: llfndecl,
llenv: None,
llretptr: Cell::new(None),
entry_bcx: RefCell::new(None),
alloca_insert_pt: Cell::new(None),
llreturn: Cell::new(None),
personality: Cell::new(None),
caller_expects_out_pointer: uses_outptr,
llargs: RefCell::new(NodeMap::new()),
lllocals: RefCell::new(NodeMap::new()),
llupvars: RefCell::new(NodeMap::new()),
id: id,
param_substs: param_substs,
span: sp,
block_arena: block_arena,
ccx: ccx,
debug_context: debug_context,
scopes: RefCell::new(Vec::new())
};
if has_env {
fcx.llenv = Some(unsafe {
llvm::LLVMGetParam(fcx.llfn, fcx.env_arg_pos() as c_uint)
});
}
fcx
}
/// Performs setup on a newly created function, creating the entry scope block
/// and allocating space for the return pointer.
pub fn init_function<'a>(fcx: &'a FunctionContext<'a>,
skip_retptr: bool,
output_type: ty::t) {
let entry_bcx = fcx.new_temp_block("entry-block");
*fcx.entry_bcx.borrow_mut() = Some(entry_bcx);
// Use a dummy instruction as the insertion point for all allocas.
// This is later removed in FunctionContext::cleanup.
fcx.alloca_insert_pt.set(Some(unsafe {
Load(entry_bcx, C_null(Type::i8p(fcx.ccx)));
llvm::LLVMGetFirstInstruction(entry_bcx.llbb)
}));
// This shouldn't need to recompute the return type,
// as new_fn_ctxt did it already.
let substd_output_type = output_type.substp(fcx.ccx.tcx(), fcx.param_substs);
if !return_type_is_void(fcx.ccx, substd_output_type) {
// If the function returns nil/bot, there is no real return
// value, so do not set `llretptr`.
if !skip_retptr || fcx.caller_expects_out_pointer {
// Otherwise, we normally allocate the llretptr, unless we
// have been instructed to skip it for immediate return
// values.
fcx.llretptr.set(Some(make_return_pointer(fcx, substd_output_type)));
}
}
}
// NB: must keep 4 fns in sync:
//
// - type_of_fn
// - create_datums_for_fn_args.
// - new_fn_ctxt
// - trans_args
fn arg_kind(cx: &FunctionContext, t: ty::t) -> datum::Rvalue {
use middle::trans::datum::{ByRef, ByValue};
datum::Rvalue {
mode: if arg_is_indirect(cx.ccx, t) { ByRef } else { ByValue }
}
}
// work around bizarre resolve errors
pub type RvalueDatum = datum::Datum<datum::Rvalue>;
pub type LvalueDatum = datum::Datum<datum::Lvalue>;
// create_datums_for_fn_args: creates rvalue datums for each of the
// incoming function arguments. These will later be stored into
// appropriate lvalue datums.
pub fn create_datums_for_fn_args(fcx: &FunctionContext,
arg_tys: &[ty::t])
-> Vec<RvalueDatum> {
let _icx = push_ctxt("create_datums_for_fn_args");
// Return an array wrapping the ValueRefs that we get from
// llvm::LLVMGetParam for each argument into datums.
arg_tys.iter().enumerate().map(|(i, &arg_ty)| {
let llarg = unsafe {
llvm::LLVMGetParam(fcx.llfn, fcx.arg_pos(i) as c_uint)
};
datum::Datum::new(llarg, arg_ty, arg_kind(fcx, arg_ty))
}).collect()
}
fn copy_args_to_allocas<'a>(fcx: &FunctionContext<'a>,
arg_scope: cleanup::CustomScopeIndex,
bcx: &'a Block<'a>,
args: &[ast::Arg],
arg_datums: Vec<RvalueDatum> )
-> &'a Block<'a> {
debug!("copy_args_to_allocas");
let _icx = push_ctxt("copy_args_to_allocas");
let mut bcx = bcx;
let arg_scope_id = cleanup::CustomScope(arg_scope);
for (i, arg_datum) in arg_datums.move_iter().enumerate() {
// 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.
bcx = _match::store_arg(bcx, args[i].pat, arg_datum, arg_scope_id);
if fcx.ccx.sess().opts.debuginfo == FullDebugInfo {
debuginfo::create_argument_metadata(bcx, &args[i]);
}
}
bcx
}
// Ties up the llstaticallocas -> llloadenv -> lltop edges,
// and builds the return block.
pub fn finish_fn<'a>(fcx: &'a FunctionContext<'a>,
last_bcx: &'a Block<'a>) {
let _icx = push_ctxt("finish_fn");
let ret_cx = match fcx.llreturn.get() {
Some(llreturn) => {
if !last_bcx.terminated.get() {
Br(last_bcx, llreturn);
}
raw_block(fcx, false, llreturn)
}
None => last_bcx
};
build_return_block(fcx, ret_cx);
debuginfo::clear_source_location(fcx);
fcx.cleanup();
}
// Builds the return block for a function.
pub fn build_return_block(fcx: &FunctionContext, ret_cx: &Block) {
// Return the value if this function immediate; otherwise, return void.
if fcx.llretptr.get().is_none() || fcx.caller_expects_out_pointer {
return RetVoid(ret_cx);
}
let retptr = Value(fcx.llretptr.get().unwrap());
let retval = match retptr.get_dominating_store(ret_cx) {
// 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
Some(s) => {
let retval = s.get_operand(0).unwrap().get();
s.erase_from_parent();
if retptr.has_no_uses() {
retptr.erase_from_parent();
}
retval
}
// Otherwise, load the return value from the ret slot
None => Load(ret_cx, fcx.llretptr.get().unwrap())
};
Ret(ret_cx, retval);
}
// trans_closure: 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(ccx: &CrateContext,
decl: &ast::FnDecl,
body: &ast::Block,
llfndecl: ValueRef,
param_substs: &param_substs,
id: ast::NodeId,
_attributes: &[ast::Attribute],
output_type: ty::t,
maybe_load_env: <'a> |&'a Block<'a>| -> &'a Block<'a>) {
ccx.stats.n_closures.set(ccx.stats.n_closures.get() + 1);
let _icx = push_ctxt("trans_closure");
set_uwtable(llfndecl);
debug!("trans_closure(..., param_substs={})",
param_substs.repr(ccx.tcx()));
let has_env = match ty::get(ty::node_id_to_type(ccx.tcx(), id)).sty {
ty::ty_closure(_) => true,
_ => false
};
let arena = TypedArena::new();
let fcx = new_fn_ctxt(ccx,
llfndecl,
id,
has_env,
output_type,
param_substs,
Some(body.span),
&arena);
init_function(&fcx, false, output_type);
// cleanup scope for the incoming arguments
let arg_scope = fcx.push_custom_cleanup_scope();
// Create the first basic block in the function and keep a handle on it to
// pass to finish_fn later.
let bcx_top = fcx.entry_bcx.borrow().clone().unwrap();
let mut bcx = bcx_top;
let block_ty = node_id_type(bcx, body.id);
// Set up arguments to the function.
let arg_tys = ty::ty_fn_args(node_id_type(bcx, id));
let arg_datums = create_datums_for_fn_args(&fcx, arg_tys.as_slice());
bcx = copy_args_to_allocas(&fcx,
arg_scope,
bcx,
decl.inputs.as_slice(),
arg_datums);
bcx = maybe_load_env(bcx);
// 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 = match fcx.llretptr.get() {
Some(e) => {expr::SaveIn(e)}
None => {
assert!(type_is_zero_size(bcx.ccx(), block_ty))
expr::Ignore
}
};
// 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).
bcx = controlflow::trans_block(bcx, body, dest);
match fcx.llreturn.get() {
Some(_) => {
Br(bcx, fcx.return_exit_block());
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();
for &llreturn in llreturn.iter() {
llvm::LLVMMoveBasicBlockAfter(llreturn, bcx.llbb);
}
}
// Insert the mandatory first few basic blocks before lltop.
finish_fn(&fcx, bcx);
}
// trans_fn: creates an LLVM function corresponding to a source language
// function.
pub fn trans_fn(ccx: &CrateContext,
decl: &ast::FnDecl,
body: &ast::Block,
llfndecl: ValueRef,
param_substs: &param_substs,
id: ast::NodeId,
attrs: &[ast::Attribute]) {
let _s = StatRecorder::new(ccx, ccx.tcx.map.path_to_str(id).to_string());
debug!("trans_fn(param_substs={})", param_substs.repr(ccx.tcx()));
let _icx = push_ctxt("trans_fn");
let output_type = ty::ty_fn_ret(ty::node_id_to_type(ccx.tcx(), id));
trans_closure(ccx, decl, body, llfndecl,
param_substs, id, attrs, output_type, |bcx| bcx);
}
pub fn trans_enum_variant(ccx: &CrateContext,
_enum_id: ast::NodeId,
variant: &ast::Variant,
_args: &[ast::VariantArg],
disr: ty::Disr,
param_substs: &param_substs,
llfndecl: ValueRef) {
let _icx = push_ctxt("trans_enum_variant");
trans_enum_variant_or_tuple_like_struct(
ccx,
variant.node.id,
disr,
param_substs,
llfndecl);
}
pub fn trans_tuple_struct(ccx: &CrateContext,
_fields: &[ast::StructField],
ctor_id: ast::NodeId,
param_substs: &param_substs,
llfndecl: ValueRef) {
let _icx = push_ctxt("trans_tuple_struct");
trans_enum_variant_or_tuple_like_struct(
ccx,
ctor_id,
0,
param_substs,
llfndecl);
}
fn trans_enum_variant_or_tuple_like_struct(ccx: &CrateContext,
ctor_id: ast::NodeId,
disr: ty::Disr,
param_substs: &param_substs,
llfndecl: ValueRef) {
let ctor_ty = ty::node_id_to_type(ccx.tcx(), ctor_id);
let ctor_ty = ctor_ty.substp(ccx.tcx(), param_substs);
let result_ty = match ty::get(ctor_ty).sty {
ty::ty_bare_fn(ref bft) => bft.sig.output,
_ => ccx.sess().bug(
format!("trans_enum_variant_or_tuple_like_struct: \
unexpected ctor return type {}",
ty_to_str(ccx.tcx(), ctor_ty)).as_slice())
};
let arena = TypedArena::new();
let fcx = new_fn_ctxt(ccx, llfndecl, ctor_id, false, result_ty,
param_substs, None, &arena);
init_function(&fcx, false, result_ty);
let arg_tys = ty::ty_fn_args(ctor_ty);
let arg_datums = create_datums_for_fn_args(&fcx, arg_tys.as_slice());
let bcx = fcx.entry_bcx.borrow().clone().unwrap();
if !type_is_zero_size(fcx.ccx, result_ty) {
let repr = adt::represent_type(ccx, result_ty);
adt::trans_start_init(bcx, &*repr, fcx.llretptr.get().unwrap(), disr);
for (i, arg_datum) in arg_datums.move_iter().enumerate() {
let lldestptr = adt::trans_field_ptr(bcx,
&*repr,
fcx.llretptr.get().unwrap(),
disr,
i);
arg_datum.store_to(bcx, lldestptr);
}
}
finish_fn(&fcx, bcx);
}
fn trans_enum_def(ccx: &CrateContext, enum_definition: &ast::EnumDef,
sp: Span, id: ast::NodeId, vi: &[Rc<ty::VariantInfo>],
i: &mut uint) {
for variant in enum_definition.variants.iter() {
let disr_val = vi[*i].disr_val;
*i += 1;
match variant.node.kind {
ast::TupleVariantKind(ref args) if args.len() > 0 => {
let llfn = get_item_val(ccx, variant.node.id);
trans_enum_variant(ccx, id, &**variant, args.as_slice(),
disr_val, &param_substs::empty(), llfn);
}
ast::TupleVariantKind(_) => {
// Nothing to do.
}
ast::StructVariantKind(struct_def) => {
trans_struct_def(ccx, struct_def);
}
}
}
enum_variant_size_lint(ccx, enum_definition, sp, id);
}
fn enum_variant_size_lint(ccx: &CrateContext, enum_def: &ast::EnumDef, sp: Span, id: ast::NodeId) {
let mut sizes = Vec::new(); // does no allocation if no pushes, thankfully
let (lvl, src) = ccx.tcx.node_lint_levels.borrow()
.find(&(id, lint::VariantSizeDifference))
.map_or((lint::Allow, lint::Default), |&(lvl,src)| (lvl, src));
if lvl != lint::Allow {
let avar = adt::represent_type(ccx, ty::node_id_to_type(ccx.tcx(), id));
match *avar {
adt::General(_, ref variants) => {
for var in variants.iter() {
let mut size = 0;
for field in var.fields.iter().skip(1) {
// skip the discriminant
size += llsize_of_real(ccx, sizing_type_of(ccx, *field));
}
sizes.push(size);
}
},
_ => { /* its size is either constant or unimportant */ }
}
let (largest, slargest, largest_index) = sizes.iter().enumerate().fold((0, 0, 0),
|(l, s, li), (idx, &size)|
if size > l {
(size, l, idx)
} else if size > s {
(l, size, li)
} else {
(l, s, li)
}
);
// we only warn if the largest variant is at least thrice as large as
// the second-largest.
if largest > slargest * 3 && slargest > 0 {
lint::emit_lint(lvl, src,
format!("enum variant is more than three times larger \
({} bytes) than the next largest (ignoring padding)",
largest).as_slice(),
sp, lint::lint_to_str(lint::VariantSizeDifference), ccx.tcx());
ccx.sess().span_note(enum_def.variants.get(largest_index).span,
"this variant is the largest");
}
}
}
pub struct TransItemVisitor<'a> {
pub ccx: &'a CrateContext,
}
impl<'a> Visitor<()> for TransItemVisitor<'a> {
fn visit_item(&mut self, i: &ast::Item, _:()) {
trans_item(self.ccx, i);
}
}
pub fn trans_item(ccx: &CrateContext, item: &ast::Item) {
let _icx = push_ctxt("trans_item");
match item.node {
ast::ItemFn(ref decl, _fn_style, abi, ref generics, ref body) => {
if abi != Rust {
let llfndecl = get_item_val(ccx, item.id);
foreign::trans_rust_fn_with_foreign_abi(
ccx, &**decl, &**body, item.attrs.as_slice(), llfndecl, item.id);
} else if !generics.is_type_parameterized() {
let llfn = get_item_val(ccx, item.id);
trans_fn(ccx,
&**decl,
&**body,
llfn,
&param_substs::empty(),
item.id,
item.attrs.as_slice());
} else {
// Be sure to travel more than just one layer deep to catch nested
// items in blocks and such.
let mut v = TransItemVisitor{ ccx: ccx };
v.visit_block(&**body, ());
}
}
ast::ItemImpl(ref generics, _, _, ref ms) => {
meth::trans_impl(ccx, item.ident, ms.as_slice(), generics, item.id);
}
ast::ItemMod(ref m) => {
trans_mod(ccx, m);
}
ast::ItemEnum(ref enum_definition, ref generics) => {
if !generics.is_type_parameterized() {
let vi = ty::enum_variants(ccx.tcx(), local_def(item.id));
let mut i = 0;
trans_enum_def(ccx, enum_definition, item.span, item.id, vi.as_slice(), &mut i);
}
}
ast::ItemStatic(_, m, ref expr) => {
// Recurse on the expression to catch items in blocks
let mut v = TransItemVisitor{ ccx: ccx };
v.visit_expr(&**expr, ());
consts::trans_const(ccx, m, item.id);
// Do static_assert checking. It can't really be done much earlier
// because we need to get the value of the bool out of LLVM
if attr::contains_name(item.attrs.as_slice(), "static_assert") {
if m == ast::MutMutable {
ccx.sess().span_fatal(expr.span,
"cannot have static_assert on a mutable \
static");
}
let v = ccx.const_values.borrow().get_copy(&item.id);
unsafe {
if !(llvm::LLVMConstIntGetZExtValue(v) != 0) {
ccx.sess().span_fatal(expr.span, "static assertion failed");
}
}
}
},
ast::ItemForeignMod(ref foreign_mod) => {
foreign::trans_foreign_mod(ccx, foreign_mod);
}
ast::ItemStruct(struct_def, ref generics) => {
if !generics.is_type_parameterized() {
trans_struct_def(ccx, struct_def);
}
}
ast::ItemTrait(..) => {
// Inside of this trait definition, we won't be actually translating any
// functions, but the trait still needs to be walked. Otherwise default
// methods with items will not get translated and will cause ICE's when
// metadata time comes around.
let mut v = TransItemVisitor{ ccx: ccx };
visit::walk_item(&mut v, item, ());
}
_ => {/* fall through */ }
}
}
pub fn trans_struct_def(ccx: &CrateContext, struct_def: Gc<ast::StructDef>) {
// If this is a tuple-like struct, translate the constructor.
match struct_def.ctor_id {
// We only need to translate a constructor if there are fields;
// otherwise this is a unit-like struct.
Some(ctor_id) if struct_def.fields.len() > 0 => {
let llfndecl = get_item_val(ccx, ctor_id);
trans_tuple_struct(ccx, struct_def.fields.as_slice(),
ctor_id, &param_substs::empty(), llfndecl);
}
Some(_) | None => {}
}
}
// Translate a module. Doing this amounts to translating the items in the
// module; there ends up being no artifact (aside from linkage names) of
// separate modules in the compiled program. That's because modules exist
// only as a convenience for humans working with the code, to organize names
// and control visibility.
pub fn trans_mod(ccx: &CrateContext, m: &ast::Mod) {
let _icx = push_ctxt("trans_mod");
for item in m.items.iter() {
trans_item(ccx, &**item);
}
}
fn finish_register_fn(ccx: &CrateContext, sp: Span, sym: String, node_id: ast::NodeId,
llfn: ValueRef) {
ccx.item_symbols.borrow_mut().insert(node_id, sym);
if !ccx.reachable.contains(&node_id) {
lib::llvm::SetLinkage(llfn, lib::llvm::InternalLinkage);
}
// The stack exhaustion lang item shouldn't have a split stack because
// otherwise it would continue to be exhausted (bad), and both it and the
// eh_personality functions need to be externally linkable.
let def = ast_util::local_def(node_id);
if ccx.tcx.lang_items.stack_exhausted() == Some(def) {
unset_split_stack(llfn);
lib::llvm::SetLinkage(llfn, lib::llvm::ExternalLinkage);
}
if ccx.tcx.lang_items.eh_personality() == Some(def) {
lib::llvm::SetLinkage(llfn, lib::llvm::ExternalLinkage);
}
if is_entry_fn(ccx.sess(), node_id) {
create_entry_wrapper(ccx, sp, llfn);
}
}
fn register_fn(ccx: &CrateContext,
sp: Span,
sym: String,
node_id: ast::NodeId,
node_type: ty::t)
-> ValueRef {
match ty::get(node_type).sty {
ty::ty_bare_fn(ref f) => {
assert!(f.abi == Rust || f.abi == RustIntrinsic);
}
_ => fail!("expected bare rust fn or an intrinsic")
};
let llfn = decl_rust_fn(ccx, node_type, sym.as_slice());
finish_register_fn(ccx, sp, sym, node_id, llfn);
llfn
}
pub fn get_fn_llvm_attributes(ccx: &CrateContext, fn_ty: ty::t) -> Vec<(uint, u64)> {
use middle::ty::{BrAnon, ReLateBound};
let (fn_sig, has_env) = match ty::get(fn_ty).sty {
ty::ty_closure(ref f) => (f.sig.clone(), true),
ty::ty_bare_fn(ref f) => (f.sig.clone(), false),
_ => fail!("expected closure or function.")
};
// Since index 0 is the return value of the llvm func, we start
// at either 1 or 2 depending on whether there's an env slot or not
let mut first_arg_offset = if has_env { 2 } else { 1 };
let mut attrs = Vec::new();
let ret_ty = fn_sig.output;
// A function pointer is called without the declaration
// available, so we have to apply any attributes with ABI
// implications directly to the call instruction. Right now,
// the only attribute we need to worry about is `sret`.
if type_of::return_uses_outptr(ccx, ret_ty) {
attrs.push((1, lib::llvm::StructRetAttribute as u64));
// The outptr can be noalias and nocapture because it's entirely
// invisible to the program. We can also mark it as nonnull
attrs.push((1, lib::llvm::NoAliasAttribute as u64));
attrs.push((1, lib::llvm::NoCaptureAttribute as u64));
attrs.push((1, lib::llvm::NonNullAttribute as u64));
// Add one more since there's an outptr
first_arg_offset += 1;
} else {
// The `noalias` attribute on the return value is useful to a
// function ptr caller.
match ty::get(ret_ty).sty {
// `~` pointer return values never alias because ownership
// is transferred
ty::ty_uniq(_) => {
attrs.push((lib::llvm::ReturnIndex as uint, lib::llvm::NoAliasAttribute as u64));
}
_ => {}
}
// We can also mark the return value as `nonnull` in certain cases
match ty::get(ret_ty).sty {
// These are not really pointers but pairs, (pointer, len)
ty::ty_rptr(_, ty::mt { ty: it, .. }) |
ty::ty_rptr(_, ty::mt { ty: it, .. }) if match ty::get(it).sty {
ty::ty_str | ty::ty_vec(..) => true, _ => false
} => {}
ty::ty_uniq(_) | ty::ty_rptr(_, _) => {
attrs.push((lib::llvm::ReturnIndex as uint, lib::llvm::NonNullAttribute as u64));
}
_ => {}
}
}
for (idx, &t) in fn_sig.inputs.iter().enumerate().map(|(i, v)| (i + first_arg_offset, v)) {
match ty::get(t).sty {
// this needs to be first to prevent fat pointers from falling through
_ if !type_is_immediate(ccx, t) => {
// For non-immediate arguments the callee gets its own copy of
// the value on the stack, so there are no aliases. It's also
// program-invisible so can't possibly capture
attrs.push((idx, lib::llvm::NoAliasAttribute as u64));
attrs.push((idx, lib::llvm::NoCaptureAttribute as u64));
attrs.push((idx, lib::llvm::NonNullAttribute as u64));
}
// `~` pointer parameters never alias because ownership is transferred
ty::ty_uniq(_) => {
attrs.push((idx, lib::llvm::NoAliasAttribute as u64));
attrs.push((idx, lib::llvm::NonNullAttribute as u64));
}
// `&mut` pointer parameters never alias other parameters, or mutable global data
ty::ty_rptr(b, mt) if mt.mutbl == ast::MutMutable => {
attrs.push((idx, lib::llvm::NoAliasAttribute as u64));
attrs.push((idx, lib::llvm::NonNullAttribute as u64));
match b {
ReLateBound(_, BrAnon(_)) => {
attrs.push((idx, lib::llvm::NoCaptureAttribute as u64));
}
_ => {}
}
}
// When a reference in an argument has no named lifetime, it's impossible for that
// reference to escape this function (returned or stored beyond the call by a closure).
ty::ty_rptr(ReLateBound(_, BrAnon(_)), _) => {
attrs.push((idx, lib::llvm::NoCaptureAttribute as u64));
attrs.push((idx, lib::llvm::NonNullAttribute as u64));
}
// & pointer parameters are never null
ty::ty_rptr(_, _) => {
attrs.push((idx, lib::llvm::NonNullAttribute as u64));
}
_ => ()
}
}
attrs
}
// only use this for foreign function ABIs and glue, use `register_fn` for Rust functions
pub fn register_fn_llvmty(ccx: &CrateContext,
sp: Span,
sym: String,
node_id: ast::NodeId,
cc: lib::llvm::CallConv,
llfty: Type) -> ValueRef {
debug!("register_fn_llvmty id={} sym={}", node_id, sym);
let llfn = decl_fn(ccx.llmod, sym.as_slice(), cc, llfty, ty::mk_nil());
finish_register_fn(ccx, sp, sym, node_id, llfn);
llfn
}
pub fn is_entry_fn(sess: &Session, node_id: ast::NodeId) -> bool {
match *sess.entry_fn.borrow() {
Some((entry_id, _)) => node_id == entry_id,
None => false
}
}
// Create a _rust_main(args: ~[str]) function which will be called from the
// runtime rust_start function
pub fn create_entry_wrapper(ccx: &CrateContext,
_sp: Span,
main_llfn: ValueRef) {
let et = ccx.sess().entry_type.get().unwrap();
match et {
config::EntryMain => {
create_entry_fn(ccx, main_llfn, true);
}
config::EntryStart => create_entry_fn(ccx, main_llfn, false),
config::EntryNone => {} // Do nothing.
}
fn create_entry_fn(ccx: &CrateContext,
rust_main: ValueRef,
use_start_lang_item: bool) {
let llfty = Type::func([ccx.int_type, Type::i8p(ccx).ptr_to()],
&ccx.int_type);
let llfn = decl_cdecl_fn(ccx.llmod, "main", llfty, ty::mk_nil());
let llbb = "top".with_c_str(|buf| {
unsafe {
llvm::LLVMAppendBasicBlockInContext(ccx.llcx, llfn, buf)
}
});
let bld = ccx.builder.b;
unsafe {
llvm::LLVMPositionBuilderAtEnd(bld, llbb);
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.as_slice()); }
};
let start_fn = if start_def_id.krate == ast::LOCAL_CRATE {
get_item_val(ccx, start_def_id.node)
} else {
let start_fn_type = csearch::get_type(ccx.tcx(),
start_def_id).ty;
trans_external_path(ccx, start_def_id, start_fn_type)
};
let args = {
let opaque_rust_main = "rust_main".with_c_str(|buf| {
llvm::LLVMBuildPointerCast(bld, rust_main, Type::i8p(ccx).to_ref(), buf)
});
vec!(
opaque_rust_main,
llvm::LLVMGetParam(llfn, 0),
llvm::LLVMGetParam(llfn, 1)
)
};
(start_fn, args)
} else {
debug!("using user-defined start fn");
let args = vec!(
llvm::LLVMGetParam(llfn, 0 as c_uint),
llvm::LLVMGetParam(llfn, 1 as c_uint)
);
(rust_main, args)
};
let result = llvm::LLVMBuildCall(bld,
start_fn,
args.as_ptr(),
args.len() as c_uint,
noname());
llvm::LLVMBuildRet(bld, result);
}
}
}
fn exported_name(ccx: &CrateContext, id: ast::NodeId,
ty: ty::t, attrs: &[ast::Attribute]) -> String {
match attr::first_attr_value_str_by_name(attrs, "export_name") {
// Use provided name
Some(name) => name.get().to_string(),
_ => ccx.tcx.map.with_path(id, |mut path| {
if attr::contains_name(attrs, "no_mangle") {
// Don't mangle
path.last().unwrap().to_str()
} else {
match weak_lang_items::link_name(attrs) {
Some(name) => name.get().to_string(),
None => {
// Usual name mangling
mangle_exported_name(ccx, path, ty, id)
}
}
}
})
}
}
pub fn get_item_val(ccx: &CrateContext, id: ast::NodeId) -> ValueRef {
debug!("get_item_val(id=`{:?}`)", id);
match ccx.item_vals.borrow().find_copy(&id) {
Some(v) => return v,
None => {}
}
let mut foreign = false;
let item = ccx.tcx.map.get(id);
let val = match item {
ast_map::NodeItem(i) => {
let ty = ty::node_id_to_type(ccx.tcx(), i.id);
let sym = exported_name(ccx, id, ty, i.attrs.as_slice());
let v = match i.node {
ast::ItemStatic(_, _, ref expr) => {
// If this static came from an external crate, then
// we need to get the symbol from csearch instead of
// using the current crate's name/version
// information in the hash of the symbol
debug!("making {}", sym);
let (sym, is_local) = {
match ccx.external_srcs.borrow().find(&i.id) {
Some(&did) => {
debug!("but found in other crate...");
(csearch::get_symbol(&ccx.sess().cstore,
did), false)
}
None => (sym, true)
}
};
// We need the translated value here, because for enums the
// LLVM type is not fully determined by the Rust type.
let (v, inlineable) = consts::const_expr(ccx, &**expr, is_local);
ccx.const_values.borrow_mut().insert(id, v);
let mut inlineable = inlineable;
unsafe {
let llty = llvm::LLVMTypeOf(v);
let g = sym.as_slice().with_c_str(|buf| {
llvm::LLVMAddGlobal(ccx.llmod, llty, buf)
});
if !ccx.reachable.contains(&id) {
lib::llvm::SetLinkage(g, lib::llvm::InternalLinkage);
}
// Apply the `unnamed_addr` attribute if
// requested
if attr::contains_name(i.attrs.as_slice(),
"address_insignificant") {
if ccx.reachable.contains(&id) {
ccx.sess().span_bug(i.span,
"insignificant static is reachable");
}
lib::llvm::SetUnnamedAddr(g, true);
// This is a curious case where we must make
// all of these statics inlineable. If a
// global is tagged as
// address_insignificant, then LLVM won't
// coalesce globals unless they have an
// internal linkage type. This means that
// external crates cannot use this global.
// This is a problem for things like inner
// statics in generic functions, because the
// function will be inlined into another
// crate and then attempt to link to the
// static in the original crate, only to
// find that it's not there. On the other
// side of inlininig, the crates knows to
// not declare this static as
// available_externally (because it isn't)
inlineable = true;
}
if attr::contains_name(i.attrs.as_slice(),
"thread_local") {
lib::llvm::set_thread_local(g, true);
}
if !inlineable {
debug!("{} not inlined", sym);
ccx.non_inlineable_statics.borrow_mut()
.insert(id);
}
ccx.item_symbols.borrow_mut().insert(i.id, sym);
g
}
}
ast::ItemFn(_, _, abi, _, _) => {
let llfn = if abi == Rust {
register_fn(ccx, i.span, sym, i.id, ty)
} else {
foreign::register_rust_fn_with_foreign_abi(ccx,
i.span,
sym,
i.id)
};
set_llvm_fn_attrs(i.attrs.as_slice(), llfn);
llfn
}
_ => fail!("get_item_val: weird result in table")
};
match attr::first_attr_value_str_by_name(i.attrs.as_slice(),
"link_section") {
Some(sect) => unsafe {
sect.get().with_c_str(|buf| {
llvm::LLVMSetSection(v, buf);
})
},
None => ()
}
v
}
ast_map::NodeTraitMethod(trait_method) => {
debug!("get_item_val(): processing a NodeTraitMethod");
match *trait_method {
ast::Required(_) => {
ccx.sess().bug("unexpected variant: required trait method in \
get_item_val()");
}
ast::Provided(m) => {
register_method(ccx, id, &*m)
}
}
}
ast_map::NodeMethod(m) => {
register_method(ccx, id, &*m)
}
ast_map::NodeForeignItem(ni) => {
foreign = true;
match ni.node {
ast::ForeignItemFn(..) => {
let abi = ccx.tcx.map.get_foreign_abi(id);
let ty = ty::node_id_to_type(ccx.tcx(), ni.id);
let name = foreign::link_name(&*ni);
foreign::register_foreign_item_fn(ccx, abi, ty,
name.get().as_slice(),
Some(ni.span))
}
ast::ForeignItemStatic(..) => {
foreign::register_static(ccx, &*ni)
}
}
}
ast_map::NodeVariant(ref v) => {
let llfn;
let args = match v.node.kind {
ast::TupleVariantKind(ref args) => args,
ast::StructVariantKind(_) => {
fail!("struct variant kind unexpected in get_item_val")
}
};
assert!(args.len() != 0u);
let ty = ty::node_id_to_type(ccx.tcx(), id);
let parent = ccx.tcx.map.get_parent(id);
let enm = ccx.tcx.map.expect_item(parent);
let sym = exported_name(ccx,
id,
ty,
enm.attrs.as_slice());
llfn = match enm.node {
ast::ItemEnum(_, _) => {
register_fn(ccx, (*v).span, sym, id, ty)
}
_ => fail!("NodeVariant, shouldn't happen")
};
set_inline_hint(llfn);
llfn
}
ast_map::NodeStructCtor(struct_def) => {
// Only register the constructor if this is a tuple-like struct.
let ctor_id = match struct_def.ctor_id {
None => {
ccx.sess().bug("attempt to register a constructor of \
a non-tuple-like struct")
}
Some(ctor_id) => ctor_id,
};
let parent = ccx.tcx.map.get_parent(id);
let struct_item = ccx.tcx.map.expect_item(parent);
let ty = ty::node_id_to_type(ccx.tcx(), ctor_id);
let sym = exported_name(ccx,
id,
ty,
struct_item.attrs
.as_slice());
let llfn = register_fn(ccx, struct_item.span,
sym, ctor_id, ty);
set_inline_hint(llfn);
llfn
}
ref variant => {
ccx.sess().bug(format!("get_item_val(): unexpected variant: {:?}",
variant).as_slice())
}
};
// foreign items (extern fns and extern statics) don't have internal
// linkage b/c that doesn't quite make sense. Otherwise items can
// have internal linkage if they're not reachable.
if !foreign && !ccx.reachable.contains(&id) {
lib::llvm::SetLinkage(val, lib::llvm::InternalLinkage);
}
ccx.item_vals.borrow_mut().insert(id, val);
val
}
fn register_method(ccx: &CrateContext, id: ast::NodeId,
m: &ast::Method) -> ValueRef {
let mty = ty::node_id_to_type(ccx.tcx(), id);
let sym = exported_name(ccx, id, mty, m.attrs.as_slice());
let llfn = register_fn(ccx, m.span, sym, id, mty);
set_llvm_fn_attrs(m.attrs.as_slice(), llfn);
llfn
}
pub fn p2i(ccx: &CrateContext, v: ValueRef) -> ValueRef {
unsafe {
return llvm::LLVMConstPtrToInt(v, ccx.int_type.to_ref());
}
}
pub fn crate_ctxt_to_encode_parms<'r>(cx: &'r CrateContext, ie: encoder::EncodeInlinedItem<'r>)
-> encoder::EncodeParams<'r> {
encoder::EncodeParams {
diag: cx.sess().diagnostic(),
tcx: cx.tcx(),
reexports2: &cx.exp_map2,
item_symbols: &cx.item_symbols,
non_inlineable_statics: &cx.non_inlineable_statics,
link_meta: &cx.link_meta,
cstore: &cx.sess().cstore,
encode_inlined_item: ie,
reachable: &cx.reachable,
}
}
pub fn write_metadata(cx: &CrateContext, krate: &ast::Crate) -> 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 encode_inlined_item: encoder::EncodeInlinedItem =
|ecx, ebml_w, ii| astencode::encode_inlined_item(ecx, ebml_w, ii);
let encode_parms = crate_ctxt_to_encode_parms(cx, encode_inlined_item);
let metadata = encoder::encode_metadata(encode_parms, krate);
let compressed = Vec::from_slice(encoder::metadata_encoding_version)
.append(match flate::deflate_bytes(metadata.as_slice()) {
Some(compressed) => compressed,
None => {
cx.sess().fatal("failed to compress metadata")
}
}.as_slice());
let llmeta = C_bytes(cx, compressed.as_slice());
let llconst = C_struct(cx, [llmeta], false);
let name = format!("rust_metadata_{}_{}_{}", cx.link_meta.crateid.name,
cx.link_meta.crateid.version_or_default(), cx.link_meta.crate_hash);
let llglobal = name.with_c_str(|buf| {
unsafe {
llvm::LLVMAddGlobal(cx.metadata_llmod, val_ty(llconst).to_ref(), buf)
}
});
unsafe {
llvm::LLVMSetInitializer(llglobal, llconst);
cx.sess()
.targ_cfg
.target_strs
.meta_sect_name
.as_slice()
.with_c_str(|buf| {
llvm::LLVMSetSection(llglobal, buf)
});
}
return metadata;
}
pub fn trans_crate(krate: ast::Crate,
analysis: CrateAnalysis,
output: &OutputFilenames) -> (ty::ctxt, CrateTranslation) {
let CrateAnalysis { ty_cx: tcx, exp_map2, reachable, .. } = analysis;
// Before we touch LLVM, make sure that multithreading is enabled.
unsafe {
use sync::one::{Once, ONCE_INIT};
static mut INIT: Once = ONCE_INIT;
static mut POISONED: bool = false;
INIT.doit(|| {
if llvm::LLVMStartMultithreaded() != 1 {
// use an extra bool to make sure that all future usage of LLVM
// cannot proceed despite the Once not running more than once.
POISONED = true;
}
});
if POISONED {
tcx.sess.bug("couldn't enable multi-threaded LLVM");
}
}
let link_meta = link::build_link_meta(&krate,
output.out_filestem.as_slice());
// Append ".rs" to crate name as LLVM module identifier.
//
// LLVM code generator emits a ".file filename" directive
// for ELF backends. Value of the "filename" is set as the
// LLVM module identifier. Due to a LLVM MC bug[1], LLVM
// crashes if the module identifier is same as other symbols
// such as a function name in the module.
// 1. http://llvm.org/bugs/show_bug.cgi?id=11479
let mut llmod_id = link_meta.crateid.name.clone();
llmod_id.push_str(".rs");
let ccx = CrateContext::new(llmod_id.as_slice(), tcx, exp_map2,
Sha256::new(), link_meta, reachable);
{
let _icx = push_ctxt("text");
trans_mod(&ccx, &krate.module);
}
glue::emit_tydescs(&ccx);
if ccx.sess().opts.debuginfo != NoDebugInfo {
debuginfo::finalize(&ccx);
}
// Translate the metadata.
let metadata = write_metadata(&ccx, &krate);
if ccx.sess().trans_stats() {
println!("--- trans stats ---");
println!("n_static_tydescs: {}", ccx.stats.n_static_tydescs.get());
println!("n_glues_created: {}", ccx.stats.n_glues_created.get());
println!("n_null_glues: {}", ccx.stats.n_null_glues.get());
println!("n_real_glues: {}", ccx.stats.n_real_glues.get());
println!("n_fns: {}", ccx.stats.n_fns.get());
println!("n_monos: {}", ccx.stats.n_monos.get());
println!("n_inlines: {}", ccx.stats.n_inlines.get());
println!("n_closures: {}", ccx.stats.n_closures.get());
println!("fn stats:");
ccx.stats.fn_stats.borrow_mut().sort_by(|&(_, _, insns_a), &(_, _, insns_b)| {
insns_b.cmp(&insns_a)
});
for tuple in ccx.stats.fn_stats.borrow().iter() {
match *tuple {
(ref name, ms, insns) => {
println!("{} insns, {} ms, {}", insns, ms, *name);
}
}
}
}
if ccx.sess().count_llvm_insns() {
for (k, v) in ccx.stats.llvm_insns.borrow().iter() {
println!("{:7u} {}", *v, *k);
}
}
let llcx = ccx.llcx;
let link_meta = ccx.link_meta.clone();
let llmod = ccx.llmod;
let mut reachable: Vec<String> = ccx.reachable.iter().filter_map(|id| {
ccx.item_symbols.borrow().find(id).map(|s| s.to_string())
}).collect();
// For the purposes of LTO, 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 LTO needs to preserve them.
ccx.sess().cstore.iter_crate_data(|cnum, _| {
let syms = csearch::get_reachable_extern_fns(&ccx.sess().cstore, cnum);
reachable.extend(syms.move_iter().map(|did| {
csearch::get_symbol(&ccx.sess().cstore, did)
}));
});
// Make sure that some other crucial symbols are not eliminated from the
// module. This includes the main function, the crate map (used for debug
// log settings and I/O), and finally the curious rust_stack_exhausted
// symbol. This symbol is required for use by the libmorestack library that
// we link in, so we must ensure that this symbol is not internalized (if
// defined in the crate).
reachable.push("main".to_string());
reachable.push("rust_stack_exhausted".to_string());
// referenced from .eh_frame section on some platforms
reachable.push("rust_eh_personality".to_string());
// referenced from rt/rust_try.ll
reachable.push("rust_eh_personality_catch".to_string());
let metadata_module = ccx.metadata_llmod;
let formats = ccx.tcx.dependency_formats.borrow().clone();
let no_builtins = attr::contains_name(krate.attrs.as_slice(), "no_builtins");
(ccx.tcx, CrateTranslation {
context: llcx,
module: llmod,
link: link_meta,
metadata_module: metadata_module,
metadata: metadata,
reachable: reachable,
crate_formats: formats,
no_builtins: no_builtins,
})
}
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