794 lines
33 KiB
Rust
794 lines
33 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, SetUnnamedAddr};
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use llvm::{InternalLinkage, ValueRef, Bool, True};
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use middle::{check_const, const_eval, def};
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use trans::{adt, closure, debuginfo, expr, inline, machine};
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use trans::base::{self, push_ctxt};
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use trans::common::*;
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use trans::monomorphize;
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use trans::type_::Type;
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use trans::type_of;
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use middle::subst::Substs;
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use middle::ty::{self, Ty};
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use util::ppaux::{Repr, ty_to_string};
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use std::iter::repeat;
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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)))
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}
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}
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ast::LitFloat(ref fs, t) => {
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C_floating(&fs, 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, 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) => {
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let g = addr_of(cx, C_bytes(cx, &data[..]), "binary", e.id);
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let base = ptrcast(g, Type::i8p(cx));
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let prev_const = cx.const_unsized().borrow_mut()
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.insert(base, g);
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assert!(prev_const.is_none() || prev_const == Some(g));
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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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C_struct(cx, &[base, C_uint(cx, data.len())], false)
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}
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}
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}
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pub fn ptrcast(val: ValueRef, ty: Type) -> ValueRef {
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unsafe {
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llvm::LLVMConstPointerCast(val, ty.to_ref())
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}
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}
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fn addr_of_mut(ccx: &CrateContext,
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cv: ValueRef,
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kind: &str,
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id: ast::NodeId)
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-> ValueRef {
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unsafe {
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let name = format!("{}{}\0", kind, id);
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let gv = llvm::LLVMAddGlobal(ccx.llmod(), val_ty(cv).to_ref(),
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name.as_ptr() as *const _);
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llvm::LLVMSetInitializer(gv, cv);
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SetLinkage(gv, InternalLinkage);
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SetUnnamedAddr(gv, true);
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gv
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}
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}
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pub fn addr_of(ccx: &CrateContext,
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cv: ValueRef,
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kind: &str,
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id: ast::NodeId)
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-> ValueRef {
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match ccx.const_globals().borrow().get(&cv) {
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Some(&gv) => return gv,
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None => {}
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}
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let gv = addr_of_mut(ccx, cv, kind, id);
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unsafe {
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llvm::LLVMSetGlobalConstant(gv, True);
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}
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ccx.const_globals().borrow_mut().insert(cv, gv);
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gv
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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_unsized().borrow().get(&v) {
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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<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>,
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v: ValueRef,
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ty: Ty<'tcx>)
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-> (ValueRef, Ty<'tcx>) {
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match ty::deref(ty, true) {
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Some(mt) => {
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if 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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None => {
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cx.sess().bug(&format!("unexpected dereferenceable type {}",
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ty_to_string(cx.tcx(), ty)))
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}
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}
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}
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pub fn get_const_expr<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
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def_id: ast::DefId,
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ref_expr: &ast::Expr)
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-> &'tcx ast::Expr {
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let def_id = inline::maybe_instantiate_inline(ccx, def_id);
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if def_id.krate != ast::LOCAL_CRATE {
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ccx.sess().span_bug(ref_expr.span,
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"cross crate constant could not be inlined");
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}
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let item = ccx.tcx().map.expect_item(def_id.node);
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if let ast::ItemConst(_, ref expr) = item.node {
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&**expr
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} else {
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ccx.sess().span_bug(ref_expr.span,
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&format!("get_const_val given non-constant item {}",
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item.repr(ccx.tcx())));
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}
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}
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fn get_const_val(ccx: &CrateContext,
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def_id: ast::DefId,
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ref_expr: &ast::Expr) -> ValueRef {
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let expr = get_const_expr(ccx, def_id, ref_expr);
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let empty_substs = ccx.tcx().mk_substs(Substs::trans_empty());
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get_const_expr_as_global(ccx, expr, check_const::PURE_CONST, empty_substs)
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}
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pub fn get_const_expr_as_global<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
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expr: &ast::Expr,
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qualif: check_const::ConstQualif,
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param_substs: &'tcx Substs<'tcx>)
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-> ValueRef {
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// Special-case constants to cache a common global for all uses.
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match expr.node {
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ast::ExprPath(_) => {
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let def = ccx.tcx().def_map.borrow()[expr.id];
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match def {
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def::DefConst(def_id) => {
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if !ccx.tcx().adjustments.borrow().contains_key(&expr.id) {
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return get_const_val(ccx, def_id, expr);
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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 key = (expr.id, param_substs);
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match ccx.const_values().borrow().get(&key) {
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Some(&val) => return val,
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None => {}
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}
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let val = if qualif.intersects(check_const::NON_STATIC_BORROWS) {
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// Avoid autorefs as they would create global instead of stack
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// references, even when only the latter are correct.
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let ty = monomorphize::apply_param_substs(ccx.tcx(), param_substs,
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&ty::expr_ty(ccx.tcx(), expr));
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const_expr_unadjusted(ccx, expr, ty, param_substs)
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} else {
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const_expr(ccx, expr, param_substs).0
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};
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// boolean SSA values are i1, but they have to be stored in i8 slots,
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// otherwise some LLVM optimization passes don't work as expected
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let val = unsafe {
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if llvm::LLVMTypeOf(val) == Type::i1(ccx).to_ref() {
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llvm::LLVMConstZExt(val, Type::i8(ccx).to_ref())
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} else {
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val
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}
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};
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let lvalue = addr_of(ccx, val, "const", expr.id);
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ccx.const_values().borrow_mut().insert(key, lvalue);
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lvalue
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}
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pub fn const_expr<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>,
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e: &ast::Expr,
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param_substs: &'tcx Substs<'tcx>)
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-> (ValueRef, Ty<'tcx>) {
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let ety = monomorphize::apply_param_substs(cx.tcx(), param_substs,
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&ty::expr_ty(cx.tcx(), e));
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let llconst = const_expr_unadjusted(cx, e, ety, param_substs);
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let mut llconst = llconst;
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let mut ety_adjusted = monomorphize::apply_param_substs(cx.tcx(), param_substs,
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&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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Some(ty::AdjustReifyFnPointer(_def_id)) => {
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// FIXME(#19925) once fn item types are
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// zero-sized, we'll need to do something here
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}
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Some(ty::AdjustDerefRef(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 0..adj.autoderefs-1 {
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let (dv, dt) = const_deref(cx, llconst, ty);
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llconst = dv;
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ty = dt;
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}
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}
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let second_autoref = match adj.autoref {
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None => {
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let (dv, dt) = const_deref(cx, llconst, ty);
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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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None
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}
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Some(ty::AutoUnsafe(_, opt_autoref)) |
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Some(ty::AutoPtr(_, _, opt_autoref)) => {
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if adj.autoderefs == 0 {
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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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llconst = addr_of(cx, llconst, "autoref", e.id);
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} else {
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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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ty = match ty::deref(ty, true) {
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Some(mt) => {
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if type_is_sized(cx.tcx(), mt.ty) {
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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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ty::mk_open(cx.tcx(), mt.ty)
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}
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}
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None => {
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cx.sess().bug(&format!("unexpected dereferenceable type {}",
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ty_to_string(cx.tcx(), ty)))
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}
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}
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}
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opt_autoref
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}
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Some(autoref) => {
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cx.sess().span_bug(e.span,
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&format!("unimplemented const first autoref {:?}", autoref))
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}
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};
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match second_autoref {
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None => {}
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Some(box ty::AutoUnsafe(_, None)) |
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Some(box ty::AutoPtr(_, _, None)) => {
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llconst = addr_of(cx, llconst, "autoref", e.id);
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}
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Some(box ty::AutoUnsize(ref k)) => {
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let unsized_ty = ty::unsize_ty(cx.tcx(), ty, k, e.span);
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let info = expr::unsized_info(cx, k, e.id, ty, param_substs,
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|t| ty::mk_imm_rptr(cx.tcx(), cx.tcx().mk_region(ty::ReStatic), t));
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let base = ptrcast(llconst, type_of::type_of(cx, unsized_ty).ptr_to());
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let prev_const = cx.const_unsized().borrow_mut()
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.insert(base, llconst);
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assert!(prev_const.is_none() || prev_const == Some(llconst));
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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, &[base, info], false);
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}
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Some(autoref) => {
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cx.sess().span_bug(e.span,
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&format!("unimplemented const second autoref {:?}", autoref))
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}
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}
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}
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None => {}
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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_adjusted),
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csize, tsize));
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}
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(llconst, ety_adjusted)
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}
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fn const_expr_unadjusted<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>,
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e: &ast::Expr,
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ety: Ty<'tcx>,
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param_substs: &'tcx Substs<'tcx>) -> ValueRef {
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let map_list = |exprs: &[P<ast::Expr>]| {
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exprs.iter().map(|e| const_expr(cx, &**e, param_substs).0)
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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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const_lit(cx, e, &**lit)
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}
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ast::ExprBinary(b, ref e1, ref e2) => {
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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 (te1, ty) = const_expr(cx, &**e1, param_substs);
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let is_simd = ty::type_is_simd(cx.tcx(), ty);
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let intype = if is_simd {
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ty::simd_type(cx.tcx(), ty)
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} else {
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ty
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};
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let is_float = ty::type_is_fp(intype);
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let signed = ty::type_is_signed(intype);
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let (te2, _) = const_expr(cx, &**e2, param_substs);
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let te2 = base::cast_shift_const_rhs(b, te1, te2);
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return match b.node {
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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 | ast::BiNe | ast::BiLt | ast::BiLe | ast::BiGt | ast::BiGe => {
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if is_float {
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let cmp = base::bin_op_to_fcmp_predicate(cx, b.node);
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ConstFCmp(cmp, te1, te2)
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} else {
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let cmp = base::bin_op_to_icmp_predicate(cx, b.node, signed);
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let bool_val = ConstICmp(cmp, te1, te2);
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if is_simd {
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// LLVM outputs an `< size x i1 >`, so we need to perform
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// a sign extension to get the correctly sized type.
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llvm::LLVMConstIntCast(bool_val, val_ty(te1).to_ref(), True)
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} else {
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bool_val
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}
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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, ty) = const_expr(cx, &**e, param_substs);
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let is_float = ty::type_is_fp(ty);
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return match u {
|
|
ast::UnUniq | ast::UnDeref => {
|
|
const_deref(cx, te, ty).0
|
|
}
|
|
ast::UnNot => llvm::LLVMConstNot(te),
|
|
ast::UnNeg => {
|
|
if is_float { llvm::LLVMConstFNeg(te) }
|
|
else { llvm::LLVMConstNeg(te) }
|
|
}
|
|
}
|
|
}
|
|
ast::ExprField(ref base, field) => {
|
|
let (bv, bt) = const_expr(cx, &**base, param_substs);
|
|
let brepr = adt::represent_type(cx, bt);
|
|
expr::with_field_tys(cx.tcx(), bt, None, |discr, field_tys| {
|
|
let ix = ty::field_idx_strict(cx.tcx(), field.node.name, field_tys);
|
|
adt::const_get_field(cx, &*brepr, bv, discr, ix)
|
|
})
|
|
}
|
|
ast::ExprTupField(ref base, idx) => {
|
|
let (bv, bt) = const_expr(cx, &**base, param_substs);
|
|
let brepr = adt::represent_type(cx, bt);
|
|
expr::with_field_tys(cx.tcx(), bt, None, |discr, _| {
|
|
adt::const_get_field(cx, &*brepr, bv, discr, idx.node)
|
|
})
|
|
}
|
|
|
|
ast::ExprIndex(ref base, ref index) => {
|
|
let (bv, bt) = const_expr(cx, &**base, param_substs);
|
|
let iv = match const_eval::eval_const_expr(cx.tcx(), &**index) {
|
|
const_eval::const_int(i) => i as u64,
|
|
const_eval::const_uint(u) => u,
|
|
_ => cx.sess().span_bug(index.span,
|
|
"index is not an integer-constant expression")
|
|
};
|
|
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)))
|
|
},
|
|
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)))
|
|
},
|
|
_ => cx.sess().span_bug(base.span,
|
|
&format!("index-expr base must be a vector \
|
|
or string type, found {}",
|
|
ty_to_string(cx.tcx(), bt)))
|
|
};
|
|
|
|
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 llty = type_of::type_of(cx, ety);
|
|
let (v, basety) = const_expr(cx, &**base, param_substs);
|
|
if expr::cast_is_noop(basety, ety) {
|
|
return v;
|
|
}
|
|
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) => {
|
|
ptrcast(v, llty)
|
|
}
|
|
(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(ast::MutImmutable, 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,
|
|
ast::ExprBlock(ref blk) => {
|
|
if let Some(ref sub) = blk.expr {
|
|
cur = sub;
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
_ => break,
|
|
}
|
|
}
|
|
let opt_def = cx.tcx().def_map.borrow().get(&cur.id).cloned();
|
|
if let Some(def::DefStatic(def_id, _)) = opt_def {
|
|
return get_static_val(cx, def_id, ety);
|
|
}
|
|
|
|
// If this isn't the address of a static, then keep going through
|
|
// normal constant evaluation.
|
|
let (v, _) = const_expr(cx, &**sub, param_substs);
|
|
addr_of(cx, v, "ref", e.id)
|
|
}
|
|
ast::ExprAddrOf(ast::MutMutable, ref sub) => {
|
|
let (v, _) = const_expr(cx, &**sub, param_substs);
|
|
addr_of_mut(cx, v, "ref_mut_slice", e.id)
|
|
}
|
|
ast::ExprTup(ref es) => {
|
|
let repr = adt::represent_type(cx, ety);
|
|
let vals = map_list(&es[..]);
|
|
adt::trans_const(cx, &*repr, 0, &vals[..])
|
|
}
|
|
ast::ExprStruct(_, ref fs, ref base_opt) => {
|
|
let repr = adt::represent_type(cx, ety);
|
|
|
|
let base_val = match *base_opt {
|
|
Some(ref base) => Some(const_expr(cx, &**base, param_substs)),
|
|
None => None
|
|
};
|
|
|
|
expr::with_field_tys(cx.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, param_substs).0,
|
|
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<_>>();
|
|
if ty::type_is_simd(cx.tcx(), ety) {
|
|
C_vector(&cs[..])
|
|
} else {
|
|
adt::trans_const(cx, &*repr, discr, &cs[..])
|
|
}
|
|
})
|
|
}
|
|
ast::ExprVec(ref es) => {
|
|
let unit_ty = ty::sequence_element_type(cx.tcx(), ety);
|
|
let llunitty = type_of::type_of(cx, unit_ty);
|
|
let vs = es.iter().map(|e| const_expr(cx, &**e, param_substs).0)
|
|
.collect::<Vec<_>>();
|
|
// If the vector contains enums, an LLVM array won't work.
|
|
if vs.iter().any(|vi| val_ty(*vi) != llunitty) {
|
|
C_struct(cx, &vs[..], false)
|
|
} else {
|
|
C_array(llunitty, &vs[..])
|
|
}
|
|
}
|
|
ast::ExprRepeat(ref elem, ref count) => {
|
|
let unit_ty = ty::sequence_element_type(cx.tcx(), ety);
|
|
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 unit_val = const_expr(cx, &**elem, param_substs).0;
|
|
let vs: Vec<_> = repeat(unit_val).take(n).collect();
|
|
if val_ty(unit_val) != llunitty {
|
|
C_struct(cx, &vs[..], false)
|
|
} else {
|
|
C_array(llunitty, &vs[..])
|
|
}
|
|
}
|
|
ast::ExprPath(_) | ast::ExprQPath(_) => {
|
|
let def = cx.tcx().def_map.borrow()[e.id];
|
|
match def {
|
|
def::DefFn(..) | def::DefStaticMethod(..) | def::DefMethod(..) => {
|
|
expr::trans_def_fn_unadjusted(cx, e, def, param_substs).val
|
|
}
|
|
def::DefConst(def_id) => {
|
|
const_deref_ptr(cx, get_const_val(cx, def_id, e))
|
|
}
|
|
def::DefVariant(enum_did, variant_did, _) => {
|
|
let vinfo = ty::enum_variant_with_id(cx.tcx(),
|
|
enum_did,
|
|
variant_did);
|
|
if vinfo.args.len() > 0 {
|
|
// N-ary variant.
|
|
expr::trans_def_fn_unadjusted(cx, e, def, param_substs).val
|
|
} else {
|
|
// Nullary variant.
|
|
let repr = adt::represent_type(cx, ety);
|
|
adt::trans_const(cx, &*repr, vinfo.disr_val, &[])
|
|
}
|
|
}
|
|
def::DefStruct(_) => {
|
|
if let ty::ty_bare_fn(..) = ety.sty {
|
|
// Tuple struct.
|
|
expr::trans_def_fn_unadjusted(cx, e, def, param_substs).val
|
|
} else {
|
|
// Unit struct.
|
|
C_null(type_of::type_of(cx, ety))
|
|
}
|
|
}
|
|
_ => {
|
|
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();
|
|
let arg_vals = map_list(&args[..]);
|
|
match opt_def {
|
|
Some(def::DefStruct(_)) => {
|
|
if ty::type_is_simd(cx.tcx(), ety) {
|
|
C_vector(&arg_vals[..])
|
|
} else {
|
|
let repr = adt::represent_type(cx, ety);
|
|
adt::trans_const(cx, &*repr, 0, &arg_vals[..])
|
|
}
|
|
}
|
|
Some(def::DefVariant(enum_did, variant_did, _)) => {
|
|
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,
|
|
&arg_vals[..])
|
|
}
|
|
_ => cx.sess().span_bug(e.span, "expected a struct or variant def")
|
|
}
|
|
}
|
|
ast::ExprParen(ref e) => const_expr(cx, &**e, param_substs).0,
|
|
ast::ExprBlock(ref block) => {
|
|
match block.expr {
|
|
Some(ref expr) => const_expr(cx, &**expr, param_substs).0,
|
|
None => C_nil(cx)
|
|
}
|
|
}
|
|
ast::ExprClosure(_, ref decl, ref body) => {
|
|
closure::trans_closure_expr(closure::Dest::Ignore(cx),
|
|
&**decl, &**body, e.id,
|
|
param_substs);
|
|
C_null(type_of::type_of(cx, ety))
|
|
}
|
|
_ => 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)
|
|
}
|