723 lines
32 KiB
Rust
723 lines
32 KiB
Rust
// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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use back::abi;
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use llvm;
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use llvm::{ConstFCmp, ConstICmp, SetLinkage, PrivateLinkage, ValueRef, Bool, True, False};
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use llvm::{IntEQ, IntNE, IntUGT, IntUGE, IntULT, IntULE, IntSGT, IntSGE, IntSLT, IntSLE,
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RealOEQ, RealOGT, RealOGE, RealOLT, RealOLE, RealONE};
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use metadata::csearch;
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use middle::{const_eval, def};
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use trans::{adt, closure, consts, debuginfo, expr, inline, machine};
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use trans::base::{mod, push_ctxt};
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use trans::common::*;
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use trans::type_::Type;
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use trans::type_of;
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use middle::ty::{mod, Ty};
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use util::ppaux::{Repr, ty_to_string};
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use std::c_str::ToCStr;
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use libc::c_uint;
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use syntax::{ast, ast_util};
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use syntax::ptr::P;
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pub fn const_lit(cx: &CrateContext, e: &ast::Expr, lit: &ast::Lit)
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-> ValueRef {
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let _icx = push_ctxt("trans_lit");
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debug!("const_lit: {}", lit);
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match lit.node {
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ast::LitByte(b) => C_integral(Type::uint_from_ty(cx, ast::TyU8), b as u64, false),
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ast::LitChar(i) => C_integral(Type::char(cx), i as u64, false),
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ast::LitInt(i, ast::SignedIntLit(t, _)) => {
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C_integral(Type::int_from_ty(cx, t), i, true)
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}
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ast::LitInt(u, ast::UnsignedIntLit(t)) => {
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C_integral(Type::uint_from_ty(cx, t), u, false)
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}
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ast::LitInt(i, ast::UnsuffixedIntLit(_)) => {
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let lit_int_ty = ty::node_id_to_type(cx.tcx(), e.id);
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match lit_int_ty.sty {
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ty::ty_int(t) => {
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C_integral(Type::int_from_ty(cx, t), i as u64, true)
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}
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ty::ty_uint(t) => {
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C_integral(Type::uint_from_ty(cx, t), i as u64, false)
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}
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_ => cx.sess().span_bug(lit.span,
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format!("integer literal has type {} (expected int \
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or uint)",
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ty_to_string(cx.tcx(), lit_int_ty)).as_slice())
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}
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}
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ast::LitFloat(ref fs, t) => {
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C_floating(fs.get(), Type::float_from_ty(cx, t))
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}
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ast::LitFloatUnsuffixed(ref fs) => {
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let lit_float_ty = ty::node_id_to_type(cx.tcx(), e.id);
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match lit_float_ty.sty {
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ty::ty_float(t) => {
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C_floating(fs.get(), Type::float_from_ty(cx, t))
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}
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_ => {
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cx.sess().span_bug(lit.span,
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"floating point literal doesn't have the right type");
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}
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}
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}
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ast::LitBool(b) => C_bool(cx, b),
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ast::LitStr(ref s, _) => C_str_slice(cx, (*s).clone()),
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ast::LitBinary(ref data) => C_binary_slice(cx, data.as_slice()),
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}
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}
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pub fn const_ptrcast(cx: &CrateContext, a: ValueRef, t: Type) -> ValueRef {
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unsafe {
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let b = llvm::LLVMConstPointerCast(a, t.ptr_to().to_ref());
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assert!(cx.const_globals().borrow_mut().insert(b as int, a).is_none());
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b
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}
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}
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fn const_vec(cx: &CrateContext, e: &ast::Expr,
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es: &[P<ast::Expr>]) -> (ValueRef, Type) {
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let vec_ty = ty::expr_ty(cx.tcx(), e);
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let unit_ty = ty::sequence_element_type(cx.tcx(), vec_ty);
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let llunitty = type_of::type_of(cx, unit_ty);
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let vs = es.iter().map(|e| const_expr(cx, &**e).val0())
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.collect::<Vec<_>>();
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// If the vector contains enums, an LLVM array won't work.
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let v = if vs.iter().any(|vi| val_ty(*vi) != llunitty) {
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C_struct(cx, vs.as_slice(), false)
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} else {
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C_array(llunitty, vs.as_slice())
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};
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(v, llunitty)
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}
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pub fn const_addr_of(cx: &CrateContext, cv: ValueRef, mutbl: ast::Mutability) -> ValueRef {
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unsafe {
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let gv = "const".with_c_str(|name| {
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llvm::LLVMAddGlobal(cx.llmod(), val_ty(cv).to_ref(), name)
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});
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llvm::LLVMSetInitializer(gv, cv);
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llvm::LLVMSetGlobalConstant(gv,
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if mutbl == ast::MutImmutable {True} else {False});
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SetLinkage(gv, PrivateLinkage);
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gv
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}
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}
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fn const_deref_ptr(cx: &CrateContext, v: ValueRef) -> ValueRef {
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let v = match cx.const_globals().borrow().get(&(v as int)) {
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Some(&v) => v,
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None => v
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};
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unsafe {
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llvm::LLVMGetInitializer(v)
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}
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}
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fn const_deref_newtype<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, v: ValueRef, t: Ty<'tcx>)
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-> ValueRef {
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let repr = adt::represent_type(cx, t);
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adt::const_get_field(cx, &*repr, v, 0, 0)
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}
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fn const_deref<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, v: ValueRef,
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t: Ty<'tcx>, explicit: bool)
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-> (ValueRef, Ty<'tcx>) {
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match ty::deref(t, explicit) {
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Some(ref mt) => {
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match t.sty {
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ty::ty_ptr(mt) | ty::ty_rptr(_, mt) => {
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if ty::type_is_sized(cx.tcx(), mt.ty) {
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(const_deref_ptr(cx, v), mt.ty)
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} else {
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// Derefing a fat pointer does not change the representation,
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// just the type to ty_open.
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(v, ty::mk_open(cx.tcx(), mt.ty))
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}
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}
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ty::ty_enum(..) | ty::ty_struct(..) => {
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assert!(mt.mutbl != ast::MutMutable);
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(const_deref_newtype(cx, v, t), mt.ty)
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}
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_ => {
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cx.sess().bug(format!("unexpected dereferenceable type {}",
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ty_to_string(cx.tcx(), t)).as_slice())
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}
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}
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}
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None => {
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cx.sess().bug(format!("cannot dereference const of type {}",
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ty_to_string(cx.tcx(), t)).as_slice())
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}
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}
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}
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pub fn get_const_val(cx: &CrateContext,
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mut def_id: ast::DefId) -> ValueRef {
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let contains_key = cx.const_values().borrow().contains_key(&def_id.node);
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if !ast_util::is_local(def_id) || !contains_key {
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if !ast_util::is_local(def_id) {
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def_id = inline::maybe_instantiate_inline(cx, def_id);
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}
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if let ast::ItemConst(..) = cx.tcx().map.expect_item(def_id.node).node {
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base::get_item_val(cx, def_id.node);
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}
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}
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cx.const_values().borrow()[def_id.node].clone()
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}
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pub fn const_expr<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, e: &ast::Expr)
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-> (ValueRef, Ty<'tcx>) {
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let llconst = const_expr_unadjusted(cx, e);
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let mut llconst = llconst;
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let ety = ty::expr_ty(cx.tcx(), e);
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let mut ety_adjusted = ty::expr_ty_adjusted(cx.tcx(), e);
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let opt_adj = cx.tcx().adjustments.borrow().get(&e.id).cloned();
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match opt_adj {
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None => { }
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Some(adj) => {
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match adj {
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ty::AdjustAddEnv(ty::RegionTraitStore(ty::ReStatic, _)) => {
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let def = ty::resolve_expr(cx.tcx(), e);
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let wrapper = closure::get_wrapper_for_bare_fn(cx,
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ety_adjusted,
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def,
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llconst,
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true);
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llconst = C_struct(cx, &[wrapper, C_null(Type::i8p(cx))], false)
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}
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ty::AdjustAddEnv(store) => {
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cx.sess()
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.span_bug(e.span,
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format!("unexpected static function: {}",
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store).as_slice())
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}
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ty::AdjustDerefRef(ref adj) => {
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let mut ty = ety;
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// Save the last autoderef in case we can avoid it.
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if adj.autoderefs > 0 {
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for _ in range(0, adj.autoderefs-1) {
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let (dv, dt) = const_deref(cx, llconst, ty, false);
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llconst = dv;
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ty = dt;
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}
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}
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match adj.autoref {
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None => {
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let (dv, dt) = const_deref(cx, llconst, ty, false);
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llconst = dv;
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// If we derefed a fat pointer then we will have an
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// open type here. So we need to update the type with
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// the one returned from const_deref.
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ety_adjusted = dt;
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}
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Some(ref autoref) => {
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match *autoref {
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ty::AutoUnsafe(_, None) |
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ty::AutoPtr(ty::ReStatic, _, None) => {
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// Don't copy data to do a deref+ref
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// (i.e., skip the last auto-deref).
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if adj.autoderefs == 0 {
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llconst = const_addr_of(cx, llconst, ast::MutImmutable);
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}
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}
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ty::AutoPtr(ty::ReStatic, _, Some(box ty::AutoUnsize(..))) => {
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if adj.autoderefs > 0 {
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// Seeing as we are deref'ing here and take a reference
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// again to make the pointer part of the far pointer below,
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// we just skip the whole thing. We still need the type
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// though. This works even if we don't need to deref
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// because of byref semantics. Note that this is not just
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// an optimisation, it is necessary for mutable vectors to
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// work properly.
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let (_, dt) = const_deref(cx, llconst, ty, false);
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ty = dt;
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} else {
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llconst = const_addr_of(cx, llconst, ast::MutImmutable)
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}
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match ty.sty {
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ty::ty_vec(unit_ty, Some(len)) => {
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let llunitty = type_of::type_of(cx, unit_ty);
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let llptr = const_ptrcast(cx, llconst, llunitty);
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assert_eq!(abi::FAT_PTR_ADDR, 0);
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assert_eq!(abi::FAT_PTR_EXTRA, 1);
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llconst = C_struct(cx, &[
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llptr,
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C_uint(cx, len)
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], false);
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}
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_ => cx.sess().span_bug(e.span,
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format!("unimplemented type in const unsize: {}",
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ty_to_string(cx.tcx(), ty)).as_slice())
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}
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}
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_ => {
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cx.sess()
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.span_bug(e.span,
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format!("unimplemented const \
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autoref {}",
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autoref).as_slice())
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}
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}
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}
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}
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}
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}
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}
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}
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let llty = type_of::sizing_type_of(cx, ety_adjusted);
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let csize = machine::llsize_of_alloc(cx, val_ty(llconst));
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let tsize = machine::llsize_of_alloc(cx, llty);
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if csize != tsize {
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unsafe {
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// FIXME these values could use some context
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llvm::LLVMDumpValue(llconst);
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llvm::LLVMDumpValue(C_undef(llty));
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}
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cx.sess().bug(format!("const {} of type {} has size {} instead of {}",
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e.repr(cx.tcx()), ty_to_string(cx.tcx(), ety),
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csize, tsize).as_slice());
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}
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(llconst, ety_adjusted)
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}
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// the bool returned is whether this expression can be inlined into other crates
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// if it's assigned to a static.
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fn const_expr_unadjusted(cx: &CrateContext, e: &ast::Expr) -> ValueRef {
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let map_list = |exprs: &[P<ast::Expr>]| {
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exprs.iter().map(|e| const_expr(cx, &**e).val0())
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.fold(Vec::new(), |mut l, val| { l.push(val); l })
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};
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unsafe {
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let _icx = push_ctxt("const_expr");
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return match e.node {
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ast::ExprLit(ref lit) => {
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consts::const_lit(cx, e, &**lit)
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}
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ast::ExprBinary(b, ref e1, ref e2) => {
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let (te1, _) = const_expr(cx, &**e1);
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let (te2, _) = const_expr(cx, &**e2);
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let te2 = base::cast_shift_const_rhs(b, te1, te2);
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/* Neither type is bottom, and we expect them to be unified
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* already, so the following is safe. */
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let ty = ty::expr_ty(cx.tcx(), &**e1);
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let is_float = ty::type_is_fp(ty);
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let signed = ty::type_is_signed(ty);
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return match b {
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ast::BiAdd => {
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if is_float { llvm::LLVMConstFAdd(te1, te2) }
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else { llvm::LLVMConstAdd(te1, te2) }
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}
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ast::BiSub => {
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if is_float { llvm::LLVMConstFSub(te1, te2) }
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else { llvm::LLVMConstSub(te1, te2) }
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}
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ast::BiMul => {
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if is_float { llvm::LLVMConstFMul(te1, te2) }
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else { llvm::LLVMConstMul(te1, te2) }
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}
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ast::BiDiv => {
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if is_float { llvm::LLVMConstFDiv(te1, te2) }
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else if signed { llvm::LLVMConstSDiv(te1, te2) }
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else { llvm::LLVMConstUDiv(te1, te2) }
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}
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ast::BiRem => {
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if is_float { llvm::LLVMConstFRem(te1, te2) }
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else if signed { llvm::LLVMConstSRem(te1, te2) }
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else { llvm::LLVMConstURem(te1, te2) }
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}
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ast::BiAnd => llvm::LLVMConstAnd(te1, te2),
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ast::BiOr => llvm::LLVMConstOr(te1, te2),
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ast::BiBitXor => llvm::LLVMConstXor(te1, te2),
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ast::BiBitAnd => llvm::LLVMConstAnd(te1, te2),
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ast::BiBitOr => llvm::LLVMConstOr(te1, te2),
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ast::BiShl => llvm::LLVMConstShl(te1, te2),
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ast::BiShr => {
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if signed { llvm::LLVMConstAShr(te1, te2) }
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else { llvm::LLVMConstLShr(te1, te2) }
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}
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ast::BiEq => {
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if is_float { ConstFCmp(RealOEQ, te1, te2) }
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else { ConstICmp(IntEQ, te1, te2) }
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},
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ast::BiLt => {
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if is_float { ConstFCmp(RealOLT, te1, te2) }
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else {
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if signed { ConstICmp(IntSLT, te1, te2) }
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else { ConstICmp(IntULT, te1, te2) }
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}
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},
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ast::BiLe => {
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if is_float { ConstFCmp(RealOLE, te1, te2) }
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else {
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if signed { ConstICmp(IntSLE, te1, te2) }
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else { ConstICmp(IntULE, te1, te2) }
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}
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},
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ast::BiNe => {
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if is_float { ConstFCmp(RealONE, te1, te2) }
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else { ConstICmp(IntNE, te1, te2) }
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},
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ast::BiGe => {
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if is_float { ConstFCmp(RealOGE, te1, te2) }
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else {
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if signed { ConstICmp(IntSGE, te1, te2) }
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else { ConstICmp(IntUGE, te1, te2) }
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}
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},
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ast::BiGt => {
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if is_float { ConstFCmp(RealOGT, te1, te2) }
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else {
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if signed { ConstICmp(IntSGT, te1, te2) }
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else { ConstICmp(IntUGT, te1, te2) }
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}
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},
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}
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},
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ast::ExprUnary(u, ref e) => {
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let (te, _) = const_expr(cx, &**e);
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let ty = ty::expr_ty(cx.tcx(), &**e);
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let is_float = ty::type_is_fp(ty);
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return match u {
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ast::UnUniq | ast::UnDeref => {
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let (dv, _dt) = const_deref(cx, te, ty, true);
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dv
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}
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ast::UnNot => llvm::LLVMConstNot(te),
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ast::UnNeg => {
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if is_float { llvm::LLVMConstFNeg(te) }
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else { llvm::LLVMConstNeg(te) }
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}
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}
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}
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ast::ExprField(ref base, field) => {
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let (bv, bt) = const_expr(cx, &**base);
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let brepr = adt::represent_type(cx, bt);
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expr::with_field_tys(cx.tcx(), bt, None, |discr, field_tys| {
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let ix = ty::field_idx_strict(cx.tcx(), field.node.name, field_tys);
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adt::const_get_field(cx, &*brepr, bv, discr, ix)
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})
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}
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ast::ExprTupField(ref base, idx) => {
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let (bv, bt) = const_expr(cx, &**base);
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let brepr = adt::represent_type(cx, bt);
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expr::with_field_tys(cx.tcx(), bt, None, |discr, _| {
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adt::const_get_field(cx, &*brepr, bv, discr, idx.node)
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})
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}
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ast::ExprIndex(ref base, ref index) => {
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let (bv, bt) = const_expr(cx, &**base);
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let iv = match const_eval::eval_const_expr(cx.tcx(), &**index) {
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const_eval::const_int(i) => i as u64,
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const_eval::const_uint(u) => u,
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_ => cx.sess().span_bug(index.span,
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"index is not an integer-constant expression")
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};
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let (arr, len) = match bt.sty {
|
|
ty::ty_vec(_, Some(u)) => (bv, C_uint(cx, u)),
|
|
ty::ty_open(ty) => match ty.sty {
|
|
ty::ty_vec(_, None) | ty::ty_str => {
|
|
let e1 = const_get_elt(cx, bv, &[0]);
|
|
(const_deref_ptr(cx, e1), const_get_elt(cx, bv, &[1]))
|
|
},
|
|
_ => cx.sess().span_bug(base.span,
|
|
format!("index-expr base must be a vector \
|
|
or string type, found {}",
|
|
ty_to_string(cx.tcx(), bt)).as_slice())
|
|
},
|
|
ty::ty_rptr(_, mt) => match mt.ty.sty {
|
|
ty::ty_vec(_, Some(u)) => {
|
|
(const_deref_ptr(cx, bv), C_uint(cx, u))
|
|
},
|
|
_ => cx.sess().span_bug(base.span,
|
|
format!("index-expr base must be a vector \
|
|
or string type, found {}",
|
|
ty_to_string(cx.tcx(), bt)).as_slice())
|
|
},
|
|
_ => cx.sess().span_bug(base.span,
|
|
format!("index-expr base must be a vector \
|
|
or string type, found {}",
|
|
ty_to_string(cx.tcx(), bt)).as_slice())
|
|
};
|
|
|
|
let len = llvm::LLVMConstIntGetZExtValue(len) as u64;
|
|
let len = match bt.sty {
|
|
ty::ty_uniq(ty) | ty::ty_rptr(_, ty::mt{ty, ..}) => match ty.sty {
|
|
ty::ty_str => {
|
|
assert!(len > 0);
|
|
len - 1
|
|
}
|
|
_ => len
|
|
},
|
|
_ => len
|
|
};
|
|
if iv >= len {
|
|
// FIXME #3170: report this earlier on in the const-eval
|
|
// pass. Reporting here is a bit late.
|
|
cx.sess().span_err(e.span,
|
|
"const index-expr is out of bounds");
|
|
}
|
|
const_get_elt(cx, arr, &[iv as c_uint])
|
|
}
|
|
ast::ExprCast(ref base, _) => {
|
|
let ety = ty::expr_ty(cx.tcx(), e);
|
|
let llty = type_of::type_of(cx, ety);
|
|
let (v, basety) = const_expr(cx, &**base);
|
|
return match (expr::cast_type_kind(cx.tcx(), basety),
|
|
expr::cast_type_kind(cx.tcx(), ety)) {
|
|
|
|
(expr::cast_integral, expr::cast_integral) => {
|
|
let s = ty::type_is_signed(basety) as Bool;
|
|
llvm::LLVMConstIntCast(v, llty.to_ref(), s)
|
|
}
|
|
(expr::cast_integral, expr::cast_float) => {
|
|
if ty::type_is_signed(basety) {
|
|
llvm::LLVMConstSIToFP(v, llty.to_ref())
|
|
} else {
|
|
llvm::LLVMConstUIToFP(v, llty.to_ref())
|
|
}
|
|
}
|
|
(expr::cast_float, expr::cast_float) => {
|
|
llvm::LLVMConstFPCast(v, llty.to_ref())
|
|
}
|
|
(expr::cast_float, expr::cast_integral) => {
|
|
if ty::type_is_signed(ety) { llvm::LLVMConstFPToSI(v, llty.to_ref()) }
|
|
else { llvm::LLVMConstFPToUI(v, llty.to_ref()) }
|
|
}
|
|
(expr::cast_enum, expr::cast_integral) => {
|
|
let repr = adt::represent_type(cx, basety);
|
|
let discr = adt::const_get_discrim(cx, &*repr, v);
|
|
let iv = C_integral(cx.int_type(), discr, false);
|
|
let ety_cast = expr::cast_type_kind(cx.tcx(), ety);
|
|
match ety_cast {
|
|
expr::cast_integral => {
|
|
let s = ty::type_is_signed(ety) as Bool;
|
|
llvm::LLVMConstIntCast(iv, llty.to_ref(), s)
|
|
}
|
|
_ => cx.sess().bug("enum cast destination is not \
|
|
integral")
|
|
}
|
|
}
|
|
(expr::cast_pointer, expr::cast_pointer) => {
|
|
llvm::LLVMConstPointerCast(v, llty.to_ref())
|
|
}
|
|
(expr::cast_integral, expr::cast_pointer) => {
|
|
llvm::LLVMConstIntToPtr(v, llty.to_ref())
|
|
}
|
|
(expr::cast_pointer, expr::cast_integral) => {
|
|
llvm::LLVMConstPtrToInt(v, llty.to_ref())
|
|
}
|
|
_ => {
|
|
cx.sess().impossible_case(e.span,
|
|
"bad combination of types for cast")
|
|
}
|
|
}
|
|
}
|
|
ast::ExprAddrOf(mutbl, ref sub) => {
|
|
// If this is the address of some static, then we need to return
|
|
// the actual address of the static itself (short circuit the rest
|
|
// of const eval).
|
|
let mut cur = sub;
|
|
loop {
|
|
match cur.node {
|
|
ast::ExprParen(ref sub) => cur = sub,
|
|
_ => break,
|
|
}
|
|
}
|
|
let opt_def = cx.tcx().def_map.borrow().get(&cur.id).cloned();
|
|
if let Some(def::DefStatic(def_id, _)) = opt_def {
|
|
let ty = ty::expr_ty(cx.tcx(), e);
|
|
return get_static_val(cx, def_id, ty);
|
|
}
|
|
|
|
// If this isn't the address of a static, then keep going through
|
|
// normal constant evaluation.
|
|
let (e, _) = const_expr(cx, &**sub);
|
|
const_addr_of(cx, e, mutbl)
|
|
}
|
|
ast::ExprTup(ref es) => {
|
|
let ety = ty::expr_ty(cx.tcx(), e);
|
|
let repr = adt::represent_type(cx, ety);
|
|
let vals = map_list(es.as_slice());
|
|
adt::trans_const(cx, &*repr, 0, vals.as_slice())
|
|
}
|
|
ast::ExprStruct(_, ref fs, ref base_opt) => {
|
|
let ety = ty::expr_ty(cx.tcx(), e);
|
|
let repr = adt::represent_type(cx, ety);
|
|
let tcx = cx.tcx();
|
|
|
|
let base_val = match *base_opt {
|
|
Some(ref base) => Some(const_expr(cx, &**base)),
|
|
None => None
|
|
};
|
|
|
|
expr::with_field_tys(tcx, ety, Some(e.id), |discr, field_tys| {
|
|
let cs = field_tys.iter().enumerate()
|
|
.map(|(ix, &field_ty)| {
|
|
match fs.iter().find(|f| field_ty.name == f.ident.node.name) {
|
|
Some(ref f) => const_expr(cx, &*f.expr).val0(),
|
|
None => {
|
|
match base_val {
|
|
Some((bv, _)) => {
|
|
adt::const_get_field(cx, &*repr, bv,
|
|
discr, ix)
|
|
}
|
|
None => {
|
|
cx.sess().span_bug(e.span,
|
|
"missing struct field")
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}).collect::<Vec<_>>();
|
|
adt::trans_const(cx, &*repr, discr, cs.as_slice())
|
|
})
|
|
}
|
|
ast::ExprVec(ref es) => {
|
|
const_vec(cx, e, es.as_slice()).val0()
|
|
}
|
|
ast::ExprRepeat(ref elem, ref count) => {
|
|
let vec_ty = ty::expr_ty(cx.tcx(), e);
|
|
let unit_ty = ty::sequence_element_type(cx.tcx(), vec_ty);
|
|
let llunitty = type_of::type_of(cx, unit_ty);
|
|
let n = match const_eval::eval_const_expr(cx.tcx(), &**count) {
|
|
const_eval::const_int(i) => i as uint,
|
|
const_eval::const_uint(i) => i as uint,
|
|
_ => cx.sess().span_bug(count.span, "count must be integral const expression.")
|
|
};
|
|
let vs = Vec::from_elem(n, const_expr(cx, &**elem).val0());
|
|
if vs.iter().any(|vi| val_ty(*vi) != llunitty) {
|
|
C_struct(cx, vs.as_slice(), false)
|
|
} else {
|
|
C_array(llunitty, vs.as_slice())
|
|
}
|
|
}
|
|
ast::ExprPath(ref pth) => {
|
|
// Assert that there are no type parameters in this path.
|
|
assert!(pth.segments.iter().all(|seg| !seg.parameters.has_types()));
|
|
|
|
let opt_def = cx.tcx().def_map.borrow().get(&e.id).cloned();
|
|
match opt_def {
|
|
Some(def::DefFn(def_id, _)) => {
|
|
if !ast_util::is_local(def_id) {
|
|
let ty = csearch::get_type(cx.tcx(), def_id).ty;
|
|
base::trans_external_path(cx, def_id, ty)
|
|
} else {
|
|
assert!(ast_util::is_local(def_id));
|
|
base::get_item_val(cx, def_id.node)
|
|
}
|
|
}
|
|
Some(def::DefConst(def_id)) => {
|
|
get_const_val(cx, def_id)
|
|
}
|
|
Some(def::DefVariant(enum_did, variant_did, _)) => {
|
|
let ety = ty::expr_ty(cx.tcx(), e);
|
|
let repr = adt::represent_type(cx, ety);
|
|
let vinfo = ty::enum_variant_with_id(cx.tcx(),
|
|
enum_did,
|
|
variant_did);
|
|
adt::trans_const(cx, &*repr, vinfo.disr_val, &[])
|
|
}
|
|
Some(def::DefStruct(_)) => {
|
|
let ety = ty::expr_ty(cx.tcx(), e);
|
|
let llty = type_of::type_of(cx, ety);
|
|
C_null(llty)
|
|
}
|
|
_ => {
|
|
cx.sess().span_bug(e.span, "expected a const, fn, struct, \
|
|
or variant def")
|
|
}
|
|
}
|
|
}
|
|
ast::ExprCall(ref callee, ref args) => {
|
|
let opt_def = cx.tcx().def_map.borrow().get(&callee.id).cloned();
|
|
match opt_def {
|
|
Some(def::DefStruct(_)) => {
|
|
let ety = ty::expr_ty(cx.tcx(), e);
|
|
let repr = adt::represent_type(cx, ety);
|
|
let arg_vals = map_list(args.as_slice());
|
|
adt::trans_const(cx, &*repr, 0, arg_vals.as_slice())
|
|
}
|
|
Some(def::DefVariant(enum_did, variant_did, _)) => {
|
|
let ety = ty::expr_ty(cx.tcx(), e);
|
|
let repr = adt::represent_type(cx, ety);
|
|
let vinfo = ty::enum_variant_with_id(cx.tcx(),
|
|
enum_did,
|
|
variant_did);
|
|
let arg_vals = map_list(args.as_slice());
|
|
adt::trans_const(cx,
|
|
&*repr,
|
|
vinfo.disr_val,
|
|
arg_vals.as_slice())
|
|
}
|
|
_ => cx.sess().span_bug(e.span, "expected a struct or variant def")
|
|
}
|
|
}
|
|
ast::ExprParen(ref e) => const_expr(cx, &**e).val0(),
|
|
ast::ExprBlock(ref block) => {
|
|
match block.expr {
|
|
Some(ref expr) => const_expr(cx, &**expr).val0(),
|
|
None => C_nil(cx)
|
|
}
|
|
}
|
|
_ => cx.sess().span_bug(e.span,
|
|
"bad constant expression type in consts::const_expr")
|
|
};
|
|
}
|
|
}
|
|
|
|
pub fn trans_static(ccx: &CrateContext, m: ast::Mutability, id: ast::NodeId) {
|
|
unsafe {
|
|
let _icx = push_ctxt("trans_static");
|
|
let g = base::get_item_val(ccx, id);
|
|
// At this point, get_item_val has already translated the
|
|
// constant's initializer to determine its LLVM type.
|
|
let v = ccx.static_values().borrow()[id].clone();
|
|
// boolean SSA values are i1, but they have to be stored in i8 slots,
|
|
// otherwise some LLVM optimization passes don't work as expected
|
|
let v = if llvm::LLVMTypeOf(v) == Type::i1(ccx).to_ref() {
|
|
llvm::LLVMConstZExt(v, Type::i8(ccx).to_ref())
|
|
} else {
|
|
v
|
|
};
|
|
llvm::LLVMSetInitializer(g, v);
|
|
|
|
// As an optimization, all shared statics which do not have interior
|
|
// mutability are placed into read-only memory.
|
|
if m != ast::MutMutable {
|
|
let node_ty = ty::node_id_to_type(ccx.tcx(), id);
|
|
let tcontents = ty::type_contents(ccx.tcx(), node_ty);
|
|
if !tcontents.interior_unsafe() {
|
|
llvm::LLVMSetGlobalConstant(g, True);
|
|
}
|
|
}
|
|
debuginfo::create_global_var_metadata(ccx, id, g);
|
|
}
|
|
}
|
|
|
|
fn get_static_val<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, did: ast::DefId,
|
|
ty: Ty<'tcx>) -> ValueRef {
|
|
if ast_util::is_local(did) { return base::get_item_val(ccx, did.node) }
|
|
base::trans_external_path(ccx, did, ty)
|
|
}
|