rust/src/librustc_trans/trans/common.rs

1174 lines
39 KiB
Rust

// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![allow(non_camel_case_types, non_snake_case)]
//! Code that is useful in various trans modules.
pub use self::ExprOrMethodCall::*;
use session::Session;
use llvm;
use llvm::{ValueRef, BasicBlockRef, BuilderRef, ContextRef};
use llvm::{True, False, Bool};
use middle::cfg;
use middle::def;
use middle::infer;
use middle::lang_items::LangItem;
use middle::mem_categorization as mc;
use middle::region;
use middle::subst::{self, Subst, Substs};
use trans::base;
use trans::build;
use trans::cleanup;
use trans::consts;
use trans::datum;
use trans::debuginfo::{self, DebugLoc};
use trans::machine;
use trans::monomorphize;
use trans::type_::Type;
use trans::type_of;
use middle::traits;
use middle::ty::{self, HasProjectionTypes, Ty};
use middle::ty_fold;
use middle::ty_fold::{TypeFolder, TypeFoldable};
use util::ppaux::Repr;
use util::nodemap::{FnvHashMap, NodeMap};
use arena::TypedArena;
use libc::{c_uint, c_char};
use std::ffi::CString;
use std::cell::{Cell, RefCell};
use std::vec::Vec;
use syntax::ast::Ident;
use syntax::ast;
use syntax::ast_map::{PathElem, PathName};
use syntax::codemap::{DUMMY_SP, Span};
use syntax::parse::token::InternedString;
use syntax::parse::token;
use util::common::memoized;
use util::nodemap::FnvHashSet;
pub use trans::context::CrateContext;
/// Returns an equivalent value with all free regions removed (note
/// that late-bound regions remain, because they are important for
/// subtyping, but they are anonymized and normalized as well). This
/// is a stronger, caching version of `ty_fold::erase_regions`.
pub fn erase_regions<'tcx,T>(cx: &ty::ctxt<'tcx>, value: &T) -> T
where T : TypeFoldable<'tcx> + Repr<'tcx>
{
let value1 = value.fold_with(&mut RegionEraser(cx));
debug!("erase_regions({}) = {}",
value.repr(cx), value1.repr(cx));
return value1;
struct RegionEraser<'a, 'tcx: 'a>(&'a ty::ctxt<'tcx>);
impl<'a, 'tcx> TypeFolder<'tcx> for RegionEraser<'a, 'tcx> {
fn tcx(&self) -> &ty::ctxt<'tcx> { self.0 }
fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> {
match self.tcx().normalized_cache.borrow().get(&ty).cloned() {
None => {}
Some(u) => return u
}
let t_norm = ty_fold::super_fold_ty(self, ty);
self.tcx().normalized_cache.borrow_mut().insert(ty, t_norm);
return t_norm;
}
fn fold_binder<T>(&mut self, t: &ty::Binder<T>) -> ty::Binder<T>
where T : TypeFoldable<'tcx> + Repr<'tcx>
{
let u = ty::anonymize_late_bound_regions(self.tcx(), t);
ty_fold::super_fold_binder(self, &u)
}
fn fold_region(&mut self, r: ty::Region) -> ty::Region {
// because late-bound regions affect subtyping, we can't
// erase the bound/free distinction, but we can replace
// all free regions with 'static.
//
// Note that we *CAN* replace early-bound regions -- the
// type system never "sees" those, they get substituted
// away. In trans, they will always be erased to 'static
// whenever a substitution occurs.
match r {
ty::ReLateBound(..) => r,
_ => ty::ReStatic
}
}
fn fold_substs(&mut self,
substs: &subst::Substs<'tcx>)
-> subst::Substs<'tcx> {
subst::Substs { regions: subst::ErasedRegions,
types: substs.types.fold_with(self) }
}
}
}
// Is the type's representation size known at compile time?
pub fn type_is_sized<'tcx>(tcx: &ty::ctxt<'tcx>, ty: Ty<'tcx>) -> bool {
let param_env = ty::empty_parameter_environment(tcx);
ty::type_is_sized(&param_env, DUMMY_SP, ty)
}
pub fn lltype_is_sized<'tcx>(cx: &ty::ctxt<'tcx>, ty: Ty<'tcx>) -> bool {
match ty.sty {
ty::ty_open(_) => true,
_ => type_is_sized(cx, ty),
}
}
pub fn type_is_fat_ptr<'tcx>(cx: &ty::ctxt<'tcx>, ty: Ty<'tcx>) -> bool {
match ty.sty {
ty::ty_ptr(ty::mt{ty, ..}) |
ty::ty_rptr(_, ty::mt{ty, ..}) |
ty::ty_uniq(ty) => {
!type_is_sized(cx, ty)
}
_ => {
false
}
}
}
// Return the smallest part of `ty` which is unsized. Fails if `ty` is sized.
// 'Smallest' here means component of the static representation of the type; not
// the size of an object at runtime.
pub fn unsized_part_of_type<'tcx>(cx: &ty::ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
match ty.sty {
ty::ty_str | ty::ty_trait(..) | ty::ty_vec(..) => ty,
ty::ty_struct(def_id, substs) => {
let unsized_fields: Vec<_> =
ty::struct_fields(cx, def_id, substs)
.iter()
.map(|f| f.mt.ty)
.filter(|ty| !type_is_sized(cx, *ty))
.collect();
// Exactly one of the fields must be unsized.
assert!(unsized_fields.len() == 1);
unsized_part_of_type(cx, unsized_fields[0])
}
_ => {
assert!(type_is_sized(cx, ty),
"unsized_part_of_type failed even though ty is unsized");
panic!("called unsized_part_of_type with sized ty");
}
}
}
// Some things don't need cleanups during unwinding because the
// task can free them all at once later. Currently only things
// that only contain scalars and shared boxes can avoid unwind
// cleanups.
pub fn type_needs_unwind_cleanup<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, ty: Ty<'tcx>) -> bool {
return memoized(ccx.needs_unwind_cleanup_cache(), ty, |ty| {
type_needs_unwind_cleanup_(ccx.tcx(), ty, &mut FnvHashSet())
});
fn type_needs_unwind_cleanup_<'tcx>(tcx: &ty::ctxt<'tcx>,
ty: Ty<'tcx>,
tycache: &mut FnvHashSet<Ty<'tcx>>)
-> bool
{
// Prevent infinite recursion
if !tycache.insert(ty) {
return false;
}
let mut needs_unwind_cleanup = false;
ty::maybe_walk_ty(ty, |ty| {
needs_unwind_cleanup |= match ty.sty {
ty::ty_bool | ty::ty_int(_) | ty::ty_uint(_) |
ty::ty_float(_) | ty::ty_tup(_) | ty::ty_ptr(_) => false,
ty::ty_enum(did, substs) =>
ty::enum_variants(tcx, did).iter().any(|v|
v.args.iter().any(|&aty| {
let t = aty.subst(tcx, substs);
type_needs_unwind_cleanup_(tcx, t, tycache)
})
),
_ => true
};
!needs_unwind_cleanup
});
needs_unwind_cleanup
}
}
pub fn type_needs_drop<'tcx>(cx: &ty::ctxt<'tcx>,
ty: Ty<'tcx>)
-> bool {
ty::type_contents(cx, ty).needs_drop(cx)
}
fn type_is_newtype_immediate<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, ty: Ty<'tcx>) -> bool {
match ty.sty {
ty::ty_struct(def_id, substs) => {
let fields = ty::lookup_struct_fields(ccx.tcx(), def_id);
fields.len() == 1 && {
let ty = ty::lookup_field_type(ccx.tcx(), def_id, fields[0].id, substs);
let ty = monomorphize::normalize_associated_type(ccx.tcx(), &ty);
type_is_immediate(ccx, ty)
}
}
_ => false
}
}
pub fn type_is_immediate<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, ty: Ty<'tcx>) -> bool {
use trans::machine::llsize_of_alloc;
use trans::type_of::sizing_type_of;
let tcx = ccx.tcx();
let simple = ty::type_is_scalar(ty) ||
ty::type_is_unique(ty) || ty::type_is_region_ptr(ty) ||
type_is_newtype_immediate(ccx, ty) ||
ty::type_is_simd(tcx, ty);
if simple && !type_is_fat_ptr(tcx, ty) {
return true;
}
if !type_is_sized(tcx, ty) {
return false;
}
match ty.sty {
ty::ty_struct(..) | ty::ty_enum(..) | ty::ty_tup(..) | ty::ty_vec(_, Some(_)) |
ty::ty_closure(..) => {
let llty = sizing_type_of(ccx, ty);
llsize_of_alloc(ccx, llty) <= llsize_of_alloc(ccx, ccx.int_type())
}
_ => type_is_zero_size(ccx, ty)
}
}
/// Identify types which have size zero at runtime.
pub fn type_is_zero_size<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, ty: Ty<'tcx>) -> bool {
use trans::machine::llsize_of_alloc;
use trans::type_of::sizing_type_of;
let llty = sizing_type_of(ccx, ty);
llsize_of_alloc(ccx, llty) == 0
}
/// Identifies types which we declare to be equivalent to `void` in C for the purpose of function
/// return types. These are `()`, bot, and uninhabited enums. Note that all such types are also
/// zero-size, but not all zero-size types use a `void` return type (in order to aid with C ABI
/// compatibility).
pub fn return_type_is_void(ccx: &CrateContext, ty: Ty) -> bool {
ty::type_is_nil(ty) || ty::type_is_empty(ccx.tcx(), ty)
}
/// Generates a unique symbol based off the name given. This is used to create
/// unique symbols for things like closures.
pub fn gensym_name(name: &str) -> PathElem {
let num = token::gensym(name).usize();
// use one colon which will get translated to a period by the mangler, and
// we're guaranteed that `num` is globally unique for this crate.
PathName(token::gensym(&format!("{}:{}", name, num)[]))
}
#[derive(Copy)]
pub struct tydesc_info<'tcx> {
pub ty: Ty<'tcx>,
pub tydesc: ValueRef,
pub size: ValueRef,
pub align: ValueRef,
pub name: ValueRef,
}
/*
* A note on nomenclature of linking: "extern", "foreign", and "upcall".
*
* An "extern" is an LLVM symbol we wind up emitting an undefined external
* reference to. This means "we don't have the thing in this compilation unit,
* please make sure you link it in at runtime". This could be a reference to
* C code found in a C library, or rust code found in a rust crate.
*
* Most "externs" are implicitly declared (automatically) as a result of a
* user declaring an extern _module_ dependency; this causes the rust driver
* to locate an extern crate, scan its compilation metadata, and emit extern
* declarations for any symbols used by the declaring crate.
*
* A "foreign" is an extern that references C (or other non-rust ABI) code.
* There is no metadata to scan for extern references so in these cases either
* a header-digester like bindgen, or manual function prototypes, have to
* serve as declarators. So these are usually given explicitly as prototype
* declarations, in rust code, with ABI attributes on them noting which ABI to
* link via.
*
* An "upcall" is a foreign call generated by the compiler (not corresponding
* to any user-written call in the code) into the runtime library, to perform
* some helper task such as bringing a task to life, allocating memory, etc.
*
*/
#[derive(Copy)]
pub struct NodeIdAndSpan {
pub id: ast::NodeId,
pub span: Span,
}
pub fn expr_info(expr: &ast::Expr) -> NodeIdAndSpan {
NodeIdAndSpan { id: expr.id, span: expr.span }
}
pub struct BuilderRef_res {
pub b: BuilderRef,
}
impl Drop for BuilderRef_res {
fn drop(&mut self) {
unsafe {
llvm::LLVMDisposeBuilder(self.b);
}
}
}
pub fn BuilderRef_res(b: BuilderRef) -> BuilderRef_res {
BuilderRef_res {
b: b
}
}
pub type ExternMap = FnvHashMap<String, ValueRef>;
pub fn validate_substs(substs: &Substs) {
assert!(substs.types.all(|t| !ty::type_needs_infer(*t)));
}
// work around bizarre resolve errors
type RvalueDatum<'tcx> = datum::Datum<'tcx, datum::Rvalue>;
type LvalueDatum<'tcx> = datum::Datum<'tcx, datum::Lvalue>;
// Function context. Every LLVM function we create will have one of
// these.
pub struct FunctionContext<'a, 'tcx: 'a> {
// The ValueRef returned from a call to llvm::LLVMAddFunction; the
// address of the first instruction in the sequence of
// instructions for this function that will go in the .text
// section of the executable we're generating.
pub llfn: ValueRef,
// always an empty parameter-environment
pub param_env: ty::ParameterEnvironment<'a, 'tcx>,
// The environment argument in a closure.
pub llenv: Option<ValueRef>,
// A pointer to where to store the return value. If the return type is
// immediate, this points to an alloca in the function. Otherwise, it's a
// pointer to the hidden first parameter of the function. After function
// construction, this should always be Some.
pub llretslotptr: Cell<Option<ValueRef>>,
// These pub elements: "hoisted basic blocks" containing
// administrative activities that have to happen in only one place in
// the function, due to LLVM's quirks.
// A marker for the place where we want to insert the function's static
// allocas, so that LLVM will coalesce them into a single alloca call.
pub alloca_insert_pt: Cell<Option<ValueRef>>,
pub llreturn: Cell<Option<BasicBlockRef>>,
// If the function has any nested return's, including something like:
// fn foo() -> Option<Foo> { Some(Foo { x: return None }) }, then
// we use a separate alloca for each return
pub needs_ret_allocas: bool,
// The a value alloca'd for calls to upcalls.rust_personality. Used when
// outputting the resume instruction.
pub personality: Cell<Option<ValueRef>>,
// True if the caller expects this fn to use the out pointer to
// return. Either way, your code should write into the slot llretslotptr
// points to, but if this value is false, that slot will be a local alloca.
pub caller_expects_out_pointer: bool,
// Maps the DefId's for local variables to the allocas created for
// them in llallocas.
pub lllocals: RefCell<NodeMap<LvalueDatum<'tcx>>>,
// Same as above, but for closure upvars
pub llupvars: RefCell<NodeMap<ValueRef>>,
// The NodeId of the function, or -1 if it doesn't correspond to
// a user-defined function.
pub id: ast::NodeId,
// If this function is being monomorphized, this contains the type
// substitutions used.
pub param_substs: &'tcx Substs<'tcx>,
// The source span and nesting context where this function comes from, for
// error reporting and symbol generation.
pub span: Option<Span>,
// The arena that blocks are allocated from.
pub block_arena: &'a TypedArena<BlockS<'a, 'tcx>>,
// This function's enclosing crate context.
pub ccx: &'a CrateContext<'a, 'tcx>,
// Used and maintained by the debuginfo module.
pub debug_context: debuginfo::FunctionDebugContext,
// Cleanup scopes.
pub scopes: RefCell<Vec<cleanup::CleanupScope<'a, 'tcx>>>,
pub cfg: Option<cfg::CFG>,
}
impl<'a, 'tcx> FunctionContext<'a, 'tcx> {
pub fn arg_pos(&self, arg: uint) -> uint {
let arg = self.env_arg_pos() + arg;
if self.llenv.is_some() {
arg + 1
} else {
arg
}
}
pub fn env_arg_pos(&self) -> uint {
if self.caller_expects_out_pointer {
1u
} else {
0u
}
}
pub fn cleanup(&self) {
unsafe {
llvm::LLVMInstructionEraseFromParent(self.alloca_insert_pt
.get()
.unwrap());
}
}
pub fn get_llreturn(&self) -> BasicBlockRef {
if self.llreturn.get().is_none() {
self.llreturn.set(Some(unsafe {
llvm::LLVMAppendBasicBlockInContext(self.ccx.llcx(), self.llfn,
"return\0".as_ptr() as *const _)
}))
}
self.llreturn.get().unwrap()
}
pub fn get_ret_slot(&self, bcx: Block<'a, 'tcx>,
output: ty::FnOutput<'tcx>,
name: &str) -> ValueRef {
if self.needs_ret_allocas {
base::alloca_no_lifetime(bcx, match output {
ty::FnConverging(output_type) => type_of::type_of(bcx.ccx(), output_type),
ty::FnDiverging => Type::void(bcx.ccx())
}, name)
} else {
self.llretslotptr.get().unwrap()
}
}
pub fn new_block(&'a self,
is_lpad: bool,
name: &str,
opt_node_id: Option<ast::NodeId>)
-> Block<'a, 'tcx> {
unsafe {
let name = CString::from_slice(name.as_bytes());
let llbb = llvm::LLVMAppendBasicBlockInContext(self.ccx.llcx(),
self.llfn,
name.as_ptr());
BlockS::new(llbb, is_lpad, opt_node_id, self)
}
}
pub fn new_id_block(&'a self,
name: &str,
node_id: ast::NodeId)
-> Block<'a, 'tcx> {
self.new_block(false, name, Some(node_id))
}
pub fn new_temp_block(&'a self,
name: &str)
-> Block<'a, 'tcx> {
self.new_block(false, name, None)
}
pub fn join_blocks(&'a self,
id: ast::NodeId,
in_cxs: &[Block<'a, 'tcx>])
-> Block<'a, 'tcx> {
let out = self.new_id_block("join", id);
let mut reachable = false;
for bcx in in_cxs {
if !bcx.unreachable.get() {
build::Br(*bcx, out.llbb, DebugLoc::None);
reachable = true;
}
}
if !reachable {
build::Unreachable(out);
}
return out;
}
pub fn monomorphize<T>(&self, value: &T) -> T
where T : TypeFoldable<'tcx> + Repr<'tcx> + HasProjectionTypes + Clone
{
monomorphize::apply_param_substs(self.ccx.tcx(),
self.param_substs,
value)
}
}
// Basic block context. We create a block context for each basic block
// (single-entry, single-exit sequence of instructions) we generate from Rust
// code. Each basic block we generate is attached to a function, typically
// with many basic blocks per function. All the basic blocks attached to a
// function are organized as a directed graph.
pub struct BlockS<'blk, 'tcx: 'blk> {
// The BasicBlockRef returned from a call to
// llvm::LLVMAppendBasicBlock(llfn, name), which adds a basic
// block to the function pointed to by llfn. We insert
// instructions into that block by way of this block context.
// The block pointing to this one in the function's digraph.
pub llbb: BasicBlockRef,
pub terminated: Cell<bool>,
pub unreachable: Cell<bool>,
// Is this block part of a landing pad?
pub is_lpad: bool,
// AST node-id associated with this block, if any. Used for
// debugging purposes only.
pub opt_node_id: Option<ast::NodeId>,
// The function context for the function to which this block is
// attached.
pub fcx: &'blk FunctionContext<'blk, 'tcx>,
}
pub type Block<'blk, 'tcx> = &'blk BlockS<'blk, 'tcx>;
impl<'blk, 'tcx> BlockS<'blk, 'tcx> {
pub fn new(llbb: BasicBlockRef,
is_lpad: bool,
opt_node_id: Option<ast::NodeId>,
fcx: &'blk FunctionContext<'blk, 'tcx>)
-> Block<'blk, 'tcx> {
fcx.block_arena.alloc(BlockS {
llbb: llbb,
terminated: Cell::new(false),
unreachable: Cell::new(false),
is_lpad: is_lpad,
opt_node_id: opt_node_id,
fcx: fcx
})
}
pub fn ccx(&self) -> &'blk CrateContext<'blk, 'tcx> {
self.fcx.ccx
}
pub fn tcx(&self) -> &'blk ty::ctxt<'tcx> {
self.fcx.ccx.tcx()
}
pub fn sess(&self) -> &'blk Session { self.fcx.ccx.sess() }
pub fn ident(&self, ident: Ident) -> String {
token::get_ident(ident).to_string()
}
pub fn node_id_to_string(&self, id: ast::NodeId) -> String {
self.tcx().map.node_to_string(id).to_string()
}
pub fn expr_to_string(&self, e: &ast::Expr) -> String {
e.repr(self.tcx())
}
pub fn def(&self, nid: ast::NodeId) -> def::Def {
match self.tcx().def_map.borrow().get(&nid) {
Some(v) => v.clone(),
None => {
self.tcx().sess.bug(&format!(
"no def associated with node id {}", nid)[]);
}
}
}
pub fn val_to_string(&self, val: ValueRef) -> String {
self.ccx().tn().val_to_string(val)
}
pub fn llty_str(&self, ty: Type) -> String {
self.ccx().tn().type_to_string(ty)
}
pub fn ty_to_string(&self, t: Ty<'tcx>) -> String {
t.repr(self.tcx())
}
pub fn to_str(&self) -> String {
format!("[block {:p}]", self)
}
pub fn monomorphize<T>(&self, value: &T) -> T
where T : TypeFoldable<'tcx> + Repr<'tcx> + HasProjectionTypes + Clone
{
monomorphize::apply_param_substs(self.tcx(),
self.fcx.param_substs,
value)
}
}
impl<'blk, 'tcx> mc::Typer<'tcx> for BlockS<'blk, 'tcx> {
fn tcx<'a>(&'a self) -> &'a ty::ctxt<'tcx> {
self.tcx()
}
fn node_ty(&self, id: ast::NodeId) -> mc::McResult<Ty<'tcx>> {
Ok(node_id_type(self, id))
}
fn expr_ty_adjusted(&self, expr: &ast::Expr) -> mc::McResult<Ty<'tcx>> {
Ok(expr_ty_adjusted(self, expr))
}
fn node_method_ty(&self, method_call: ty::MethodCall) -> Option<Ty<'tcx>> {
self.tcx()
.method_map
.borrow()
.get(&method_call)
.map(|method| monomorphize_type(self, method.ty))
}
fn node_method_origin(&self, method_call: ty::MethodCall)
-> Option<ty::MethodOrigin<'tcx>>
{
self.tcx()
.method_map
.borrow()
.get(&method_call)
.map(|method| method.origin.clone())
}
fn adjustments<'a>(&'a self) -> &'a RefCell<NodeMap<ty::AutoAdjustment<'tcx>>> {
&self.tcx().adjustments
}
fn is_method_call(&self, id: ast::NodeId) -> bool {
self.tcx().method_map.borrow().contains_key(&ty::MethodCall::expr(id))
}
fn temporary_scope(&self, rvalue_id: ast::NodeId) -> Option<region::CodeExtent> {
self.tcx().region_maps.temporary_scope(rvalue_id)
}
fn upvar_capture(&self, upvar_id: ty::UpvarId) -> Option<ty::UpvarCapture> {
Some(self.tcx().upvar_capture_map.borrow()[upvar_id].clone())
}
fn type_moves_by_default(&self, span: Span, ty: Ty<'tcx>) -> bool {
self.fcx.param_env.type_moves_by_default(span, ty)
}
}
impl<'blk, 'tcx> ty::ClosureTyper<'tcx> for BlockS<'blk, 'tcx> {
fn param_env<'a>(&'a self) -> &'a ty::ParameterEnvironment<'a, 'tcx> {
&self.fcx.param_env
}
fn closure_kind(&self,
def_id: ast::DefId)
-> Option<ty::ClosureKind>
{
let typer = NormalizingClosureTyper::new(self.tcx());
typer.closure_kind(def_id)
}
fn closure_type(&self,
def_id: ast::DefId,
substs: &subst::Substs<'tcx>)
-> ty::ClosureTy<'tcx>
{
let typer = NormalizingClosureTyper::new(self.tcx());
typer.closure_type(def_id, substs)
}
fn closure_upvars(&self,
def_id: ast::DefId,
substs: &Substs<'tcx>)
-> Option<Vec<ty::ClosureUpvar<'tcx>>>
{
let typer = NormalizingClosureTyper::new(self.tcx());
typer.closure_upvars(def_id, substs)
}
}
pub struct Result<'blk, 'tcx: 'blk> {
pub bcx: Block<'blk, 'tcx>,
pub val: ValueRef
}
impl<'b, 'tcx> Result<'b, 'tcx> {
pub fn new(bcx: Block<'b, 'tcx>, val: ValueRef) -> Result<'b, 'tcx> {
Result {
bcx: bcx,
val: val,
}
}
}
pub fn val_ty(v: ValueRef) -> Type {
unsafe {
Type::from_ref(llvm::LLVMTypeOf(v))
}
}
// LLVM constant constructors.
pub fn C_null(t: Type) -> ValueRef {
unsafe {
llvm::LLVMConstNull(t.to_ref())
}
}
pub fn C_undef(t: Type) -> ValueRef {
unsafe {
llvm::LLVMGetUndef(t.to_ref())
}
}
pub fn C_integral(t: Type, u: u64, sign_extend: bool) -> ValueRef {
unsafe {
llvm::LLVMConstInt(t.to_ref(), u, sign_extend as Bool)
}
}
pub fn C_floating(s: &str, t: Type) -> ValueRef {
unsafe {
let s = CString::from_slice(s.as_bytes());
llvm::LLVMConstRealOfString(t.to_ref(), s.as_ptr())
}
}
pub fn C_nil(ccx: &CrateContext) -> ValueRef {
C_struct(ccx, &[], false)
}
pub fn C_bool(ccx: &CrateContext, val: bool) -> ValueRef {
C_integral(Type::i1(ccx), val as u64, false)
}
pub fn C_i32(ccx: &CrateContext, i: i32) -> ValueRef {
C_integral(Type::i32(ccx), i as u64, true)
}
pub fn C_u64(ccx: &CrateContext, i: u64) -> ValueRef {
C_integral(Type::i64(ccx), i, false)
}
pub fn C_int<I: AsI64>(ccx: &CrateContext, i: I) -> ValueRef {
let v = i.as_i64();
match machine::llbitsize_of_real(ccx, ccx.int_type()) {
32 => assert!(v < (1<<31) && v >= -(1<<31)),
64 => {},
n => panic!("unsupported target size: {}", n)
}
C_integral(ccx.int_type(), v as u64, true)
}
pub fn C_uint<I: AsU64>(ccx: &CrateContext, i: I) -> ValueRef {
let v = i.as_u64();
match machine::llbitsize_of_real(ccx, ccx.int_type()) {
32 => assert!(v < (1<<32)),
64 => {},
n => panic!("unsupported target size: {}", n)
}
C_integral(ccx.int_type(), v, false)
}
pub trait AsI64 { fn as_i64(self) -> i64; }
pub trait AsU64 { fn as_u64(self) -> u64; }
// FIXME: remove the intptr conversions, because they
// are host-architecture-dependent
impl AsI64 for i64 { fn as_i64(self) -> i64 { self as i64 }}
impl AsI64 for i32 { fn as_i64(self) -> i64 { self as i64 }}
impl AsI64 for int { fn as_i64(self) -> i64 { self as i64 }}
impl AsU64 for u64 { fn as_u64(self) -> u64 { self as u64 }}
impl AsU64 for u32 { fn as_u64(self) -> u64 { self as u64 }}
impl AsU64 for uint { fn as_u64(self) -> u64 { self as u64 }}
pub fn C_u8(ccx: &CrateContext, i: uint) -> ValueRef {
C_integral(Type::i8(ccx), i as u64, false)
}
// This is a 'c-like' raw string, which differs from
// our boxed-and-length-annotated strings.
pub fn C_cstr(cx: &CrateContext, s: InternedString, null_terminated: bool) -> ValueRef {
unsafe {
match cx.const_cstr_cache().borrow().get(&s) {
Some(&llval) => return llval,
None => ()
}
let sc = llvm::LLVMConstStringInContext(cx.llcx(),
s.as_ptr() as *const c_char,
s.len() as c_uint,
!null_terminated as Bool);
let gsym = token::gensym("str");
let buf = CString::from_vec(format!("str{}", gsym.usize()).into_bytes());
let g = llvm::LLVMAddGlobal(cx.llmod(), val_ty(sc).to_ref(), buf.as_ptr());
llvm::LLVMSetInitializer(g, sc);
llvm::LLVMSetGlobalConstant(g, True);
llvm::SetLinkage(g, llvm::InternalLinkage);
cx.const_cstr_cache().borrow_mut().insert(s, g);
g
}
}
// NB: Do not use `do_spill_noroot` to make this into a constant string, or
// you will be kicked off fast isel. See issue #4352 for an example of this.
pub fn C_str_slice(cx: &CrateContext, s: InternedString) -> ValueRef {
let len = s.len();
let cs = consts::ptrcast(C_cstr(cx, s, false), Type::i8p(cx));
C_named_struct(cx.tn().find_type("str_slice").unwrap(), &[cs, C_uint(cx, len)])
}
pub fn C_struct(cx: &CrateContext, elts: &[ValueRef], packed: bool) -> ValueRef {
C_struct_in_context(cx.llcx(), elts, packed)
}
pub fn C_struct_in_context(llcx: ContextRef, elts: &[ValueRef], packed: bool) -> ValueRef {
unsafe {
llvm::LLVMConstStructInContext(llcx,
elts.as_ptr(), elts.len() as c_uint,
packed as Bool)
}
}
pub fn C_named_struct(t: Type, elts: &[ValueRef]) -> ValueRef {
unsafe {
llvm::LLVMConstNamedStruct(t.to_ref(), elts.as_ptr(), elts.len() as c_uint)
}
}
pub fn C_array(ty: Type, elts: &[ValueRef]) -> ValueRef {
unsafe {
return llvm::LLVMConstArray(ty.to_ref(), elts.as_ptr(), elts.len() as c_uint);
}
}
pub fn C_vector(elts: &[ValueRef]) -> ValueRef {
unsafe {
return llvm::LLVMConstVector(elts.as_ptr(), elts.len() as c_uint);
}
}
pub fn C_bytes(cx: &CrateContext, bytes: &[u8]) -> ValueRef {
C_bytes_in_context(cx.llcx(), bytes)
}
pub fn C_bytes_in_context(llcx: ContextRef, bytes: &[u8]) -> ValueRef {
unsafe {
let ptr = bytes.as_ptr() as *const c_char;
return llvm::LLVMConstStringInContext(llcx, ptr, bytes.len() as c_uint, True);
}
}
pub fn const_get_elt(cx: &CrateContext, v: ValueRef, us: &[c_uint])
-> ValueRef {
unsafe {
let r = llvm::LLVMConstExtractValue(v, us.as_ptr(), us.len() as c_uint);
debug!("const_get_elt(v={}, us={:?}, r={})",
cx.tn().val_to_string(v), us, cx.tn().val_to_string(r));
return r;
}
}
pub fn is_const(v: ValueRef) -> bool {
unsafe {
llvm::LLVMIsConstant(v) == True
}
}
pub fn const_to_int(v: ValueRef) -> i64 {
unsafe {
llvm::LLVMConstIntGetSExtValue(v)
}
}
pub fn const_to_uint(v: ValueRef) -> u64 {
unsafe {
llvm::LLVMConstIntGetZExtValue(v)
}
}
pub fn is_undef(val: ValueRef) -> bool {
unsafe {
llvm::LLVMIsUndef(val) != False
}
}
#[allow(dead_code)] // potentially useful
pub fn is_null(val: ValueRef) -> bool {
unsafe {
llvm::LLVMIsNull(val) != False
}
}
pub fn monomorphize_type<'blk, 'tcx>(bcx: &BlockS<'blk, 'tcx>, t: Ty<'tcx>) -> Ty<'tcx> {
bcx.fcx.monomorphize(&t)
}
pub fn node_id_type<'blk, 'tcx>(bcx: &BlockS<'blk, 'tcx>, id: ast::NodeId) -> Ty<'tcx> {
let tcx = bcx.tcx();
let t = ty::node_id_to_type(tcx, id);
monomorphize_type(bcx, t)
}
pub fn expr_ty<'blk, 'tcx>(bcx: &BlockS<'blk, 'tcx>, ex: &ast::Expr) -> Ty<'tcx> {
node_id_type(bcx, ex.id)
}
pub fn expr_ty_adjusted<'blk, 'tcx>(bcx: &BlockS<'blk, 'tcx>, ex: &ast::Expr) -> Ty<'tcx> {
monomorphize_type(bcx, ty::expr_ty_adjusted(bcx.tcx(), ex))
}
/// Attempts to resolve an obligation. The result is a shallow vtable resolution -- meaning that we
/// do not (necessarily) resolve all nested obligations on the impl. Note that type check should
/// guarantee to us that all nested obligations *could be* resolved if we wanted to.
pub fn fulfill_obligation<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
span: Span,
trait_ref: ty::PolyTraitRef<'tcx>)
-> traits::Vtable<'tcx, ()>
{
let tcx = ccx.tcx();
// Remove any references to regions; this helps improve caching.
let trait_ref = erase_regions(tcx, &trait_ref);
// First check the cache.
match ccx.trait_cache().borrow().get(&trait_ref) {
Some(vtable) => {
info!("Cache hit: {}", trait_ref.repr(ccx.tcx()));
return (*vtable).clone();
}
None => { }
}
debug!("trans fulfill_obligation: trait_ref={}", trait_ref.repr(ccx.tcx()));
ty::populate_implementations_for_trait_if_necessary(tcx, trait_ref.def_id());
let infcx = infer::new_infer_ctxt(tcx);
// Do the initial selection for the obligation. This yields the
// shallow result we are looking for -- that is, what specific impl.
let typer = NormalizingClosureTyper::new(tcx);
let mut selcx = traits::SelectionContext::new(&infcx, &typer);
let obligation = traits::Obligation::new(traits::ObligationCause::dummy(),
trait_ref.to_poly_trait_predicate());
let selection = match selcx.select(&obligation) {
Ok(Some(selection)) => selection,
Ok(None) => {
// Ambiguity can happen when monomorphizing during trans
// expands to some humongo type that never occurred
// statically -- this humongo type can then overflow,
// leading to an ambiguous result. So report this as an
// overflow bug, since I believe this is the only case
// where ambiguity can result.
debug!("Encountered ambiguity selecting `{}` during trans, \
presuming due to overflow",
trait_ref.repr(tcx));
ccx.sess().span_fatal(
span,
"reached the recursion limit during monomorphization");
}
Err(e) => {
tcx.sess.span_bug(
span,
&format!("Encountered error `{}` selecting `{}` during trans",
e.repr(tcx),
trait_ref.repr(tcx))[])
}
};
// Currently, we use a fulfillment context to completely resolve
// all nested obligations. This is because they can inform the
// inference of the impl's type parameters.
let mut fulfill_cx = traits::FulfillmentContext::new();
let vtable = selection.map_move_nested(|predicate| {
fulfill_cx.register_predicate_obligation(&infcx, predicate);
});
let vtable = drain_fulfillment_cx(span, &infcx, &mut fulfill_cx, &vtable);
info!("Cache miss: {}", trait_ref.repr(ccx.tcx()));
ccx.trait_cache().borrow_mut().insert(trait_ref,
vtable.clone());
vtable
}
pub struct NormalizingClosureTyper<'a,'tcx:'a> {
param_env: ty::ParameterEnvironment<'a, 'tcx>
}
impl<'a,'tcx> NormalizingClosureTyper<'a,'tcx> {
pub fn new(tcx: &'a ty::ctxt<'tcx>) -> NormalizingClosureTyper<'a,'tcx> {
// Parameter environment is used to give details about type parameters,
// but since we are in trans, everything is fully monomorphized.
NormalizingClosureTyper { param_env: ty::empty_parameter_environment(tcx) }
}
}
impl<'a,'tcx> ty::ClosureTyper<'tcx> for NormalizingClosureTyper<'a,'tcx> {
fn param_env<'b>(&'b self) -> &'b ty::ParameterEnvironment<'b,'tcx> {
&self.param_env
}
fn closure_kind(&self,
def_id: ast::DefId)
-> Option<ty::ClosureKind>
{
self.param_env.closure_kind(def_id)
}
fn closure_type(&self,
def_id: ast::DefId,
substs: &subst::Substs<'tcx>)
-> ty::ClosureTy<'tcx>
{
// the substitutions in `substs` are already monomorphized,
// but we still must normalize associated types
let closure_ty = self.param_env.tcx.closure_type(def_id, substs);
monomorphize::normalize_associated_type(self.param_env.tcx, &closure_ty)
}
fn closure_upvars(&self,
def_id: ast::DefId,
substs: &Substs<'tcx>)
-> Option<Vec<ty::ClosureUpvar<'tcx>>>
{
// the substitutions in `substs` are already monomorphized,
// but we still must normalize associated types
let result = ty::closure_upvars(&self.param_env, def_id, substs);
monomorphize::normalize_associated_type(self.param_env.tcx, &result)
}
}
pub fn drain_fulfillment_cx<'a,'tcx,T>(span: Span,
infcx: &infer::InferCtxt<'a,'tcx>,
fulfill_cx: &mut traits::FulfillmentContext<'tcx>,
result: &T)
-> T
where T : TypeFoldable<'tcx> + Repr<'tcx>
{
debug!("drain_fulfillment_cx(result={})",
result.repr(infcx.tcx));
// In principle, we only need to do this so long as `result`
// contains unbound type parameters. It could be a slight
// optimization to stop iterating early.
let typer = NormalizingClosureTyper::new(infcx.tcx);
match fulfill_cx.select_all_or_error(infcx, &typer) {
Ok(()) => { }
Err(errors) => {
if errors.iter().all(|e| e.is_overflow()) {
// See Ok(None) case above.
infcx.tcx.sess.span_fatal(
span,
"reached the recursion limit during monomorphization");
} else {
infcx.tcx.sess.span_bug(
span,
&format!("Encountered errors `{}` fulfilling during trans",
errors.repr(infcx.tcx))[]);
}
}
}
// Use freshen to simultaneously replace all type variables with
// their bindings and replace all regions with 'static. This is
// sort of overkill because we do not expect there to be any
// unbound type variables, hence no `TyFresh` types should ever be
// inserted.
result.fold_with(&mut infcx.freshener())
}
// Key used to lookup values supplied for type parameters in an expr.
#[derive(Copy, PartialEq, Debug)]
pub enum ExprOrMethodCall {
// Type parameters for a path like `None::<int>`
ExprId(ast::NodeId),
// Type parameters for a method call like `a.foo::<int>()`
MethodCallKey(ty::MethodCall)
}
pub fn node_id_substs<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
node: ExprOrMethodCall,
param_substs: &subst::Substs<'tcx>)
-> subst::Substs<'tcx> {
let tcx = ccx.tcx();
let substs = match node {
ExprId(id) => {
ty::node_id_item_substs(tcx, id).substs
}
MethodCallKey(method_call) => {
(*tcx.method_map.borrow())[method_call].substs.clone()
}
};
if substs.types.any(|t| ty::type_needs_infer(*t)) {
tcx.sess.bug(&format!("type parameters for node {:?} include inference types: {:?}",
node, substs.repr(tcx))[]);
}
monomorphize::apply_param_substs(tcx,
param_substs,
&substs.erase_regions())
}
pub fn langcall(bcx: Block,
span: Option<Span>,
msg: &str,
li: LangItem)
-> ast::DefId {
match bcx.tcx().lang_items.require(li) {
Ok(id) => id,
Err(s) => {
let msg = format!("{} {}", msg, s);
match span {
Some(span) => bcx.tcx().sess.span_fatal(span, &msg[]),
None => bcx.tcx().sess.fatal(&msg[]),
}
}
}
}