// Copyright 2012 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 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. /*! * # Translation of Expressions * * Public entry points: * * - `trans_into(bcx, expr, dest) -> bcx`: evaluates an expression, * storing the result into `dest`. This is the preferred form, if you * can manage it. * * - `trans(bcx, expr) -> DatumBlock`: evaluates an expression, yielding * `Datum` with the result. You can then store the datum, inspect * the value, etc. This may introduce temporaries if the datum is a * structural type. * * - `trans_to_lvalue(bcx, expr, "...") -> DatumBlock`: evaluates an * expression and ensures that the result has a cleanup associated with it, * creating a temporary stack slot if necessary. * * - `trans_local_var -> Datum`: looks up a local variable or upvar. * * See doc.rs for more comments. */ use back::abi; use back::link; use lib::llvm::{ValueRef, llvm, SetLinkage, False}; use lib; use metadata::csearch; use middle::trans::_match; use middle::trans::adt; use middle::trans::asm; use middle::trans::base::*; use middle::trans::base; use middle::trans::build::*; use middle::trans::callee::DoAutorefArg; use middle::trans::callee; use middle::trans::cleanup; use middle::trans::cleanup::CleanupMethods; use middle::trans::closure; use middle::trans::common::*; use middle::trans::consts; use middle::trans::controlflow; use middle::trans::datum::*; use middle::trans::debuginfo; use middle::trans::glue; use middle::trans::machine; use middle::trans::meth; use middle::trans::inline; use middle::trans::tvec; use middle::trans::type_of; use middle::trans::write_guard; use middle::ty::struct_fields; use middle::ty::{AutoBorrowObj, AutoDerefRef, AutoAddEnv, AutoObject, AutoUnsafe}; use middle::ty::{AutoPtr, AutoBorrowVec, AutoBorrowVecRef, AutoBorrowFn}; use middle::ty; use util::common::indenter; use util::ppaux::Repr; use middle::trans::machine::llsize_of; use middle::trans::type_::Type; use std::hashmap::HashMap; use std::vec; use syntax::print::pprust::{expr_to_str}; use syntax::ast; use syntax::ast_map::PathMod; use syntax::codemap; // Destinations // These are passed around by the code generating functions to track the // destination of a computation's value. #[deriving(Eq)] pub enum Dest { SaveIn(ValueRef), Ignore, } impl Dest { pub fn to_str(&self, ccx: &CrateContext) -> ~str { match *self { SaveIn(v) => format!("SaveIn({})", ccx.tn.val_to_str(v)), Ignore => ~"Ignore" } } } pub fn trans_into<'a>(bcx: &'a Block<'a>, expr: &ast::Expr, dest: Dest) -> &'a Block<'a> { /*! * This function is equivalent to `trans(bcx, expr).store_to_dest(dest)` * but it may generate better optimized LLVM code. */ let mut bcx = bcx; let is_adjusted = { let adjustments = bcx.tcx().adjustments.borrow(); adjustments.get().contains_key(&expr.id) }; if is_adjusted { // use trans, which may be less efficient but // which will perform the adjustments: let datum = unpack_datum!(bcx, trans(bcx, expr)); return datum.store_to_dest(bcx, dest, expr.id) } debug!("trans_into() expr={}", expr.repr(bcx.tcx())); debuginfo::set_source_location(bcx.fcx, expr.id, expr.span); bcx.fcx.push_ast_cleanup_scope(expr.id); let kind = ty::expr_kind(bcx.tcx(), bcx.ccx().maps.method_map, expr); bcx = match kind { ty::LvalueExpr | ty::RvalueDatumExpr => { trans_unadjusted(bcx, expr).store_to_dest(dest, expr.id) } ty::RvalueDpsExpr => { trans_rvalue_dps_unadjusted(bcx, expr, dest) } ty::RvalueStmtExpr => { trans_rvalue_stmt_unadjusted(bcx, expr) } }; bcx.fcx.pop_and_trans_ast_cleanup_scope(bcx, expr.id) } pub fn trans<'a>(bcx: &'a Block<'a>, expr: &ast::Expr) -> DatumBlock<'a, Expr> { /*! * Translates an expression, returning a datum (and new block) * encapsulating the result. When possible, it is preferred to * use `trans_into`, as that may avoid creating a temporary on * the stack. */ debug!("trans(expr={})", bcx.expr_to_str(expr)); let mut bcx = bcx; let fcx = bcx.fcx; fcx.push_ast_cleanup_scope(expr.id); let datum = unpack_datum!(bcx, trans_unadjusted(bcx, expr)); let datum = unpack_datum!(bcx, apply_adjustments(bcx, expr, datum)); bcx = fcx.pop_and_trans_ast_cleanup_scope(bcx, expr.id); return DatumBlock(bcx, datum); } fn apply_adjustments<'a>(bcx: &'a Block<'a>, expr: &ast::Expr, datum: Datum) -> DatumBlock<'a, Expr> { /*! * Helper for trans that apply adjustments from `expr` to `datum`, * which should be the unadjusted translation of `expr`. */ let mut bcx = bcx; let mut datum = datum; let adjustment = { let adjustments = bcx.tcx().adjustments.borrow(); match adjustments.get().find_copy(&expr.id) { None => { return DatumBlock(bcx, datum); } Some(adj) => { adj } } }; debug!("unadjusted datum for expr {}: {}", expr.id, datum.to_str(bcx.ccx())); match *adjustment { AutoAddEnv(..) => { datum = unpack_datum!(bcx, add_env(bcx, expr, datum)); } AutoDerefRef(ref adj) => { if adj.autoderefs > 0 { datum = unpack_datum!( bcx, deref_multiple(bcx, expr, datum, adj.autoderefs)); } datum = match adj.autoref { None => { datum } Some(AutoUnsafe(..)) | // region + unsafe ptrs have same repr Some(AutoPtr(..)) => { unpack_datum!(bcx, auto_ref(bcx, datum, expr)) } Some(AutoBorrowVec(..)) => { unpack_datum!(bcx, auto_slice(bcx, adj.autoderefs, expr, datum)) } Some(AutoBorrowVecRef(..)) => { unpack_datum!(bcx, auto_slice_and_ref(bcx, adj.autoderefs, expr, datum)) } Some(AutoBorrowFn(..)) => { let adjusted_ty = ty::adjust_ty(bcx.tcx(), expr.span, datum.ty, Some(adjustment)); unpack_datum!(bcx, auto_borrow_fn(bcx, adjusted_ty, datum)) } Some(AutoBorrowObj(..)) => { unpack_datum!(bcx, auto_borrow_obj( bcx, adj.autoderefs, expr, datum)) } }; } AutoObject(..) => { let adjusted_ty = ty::expr_ty_adjusted(bcx.tcx(), expr); let scratch = rvalue_scratch_datum(bcx, adjusted_ty, "__adjust"); bcx = meth::trans_trait_cast( bcx, datum, expr.id, SaveIn(scratch.val)); datum = scratch.to_expr_datum(); } } debug!("after adjustments, datum={}", datum.to_str(bcx.ccx())); return DatumBlock {bcx: bcx, datum: datum}; fn auto_ref<'a>(bcx: &'a Block<'a>, datum: Datum, expr: &ast::Expr) -> DatumBlock<'a, Expr> { let mut bcx = bcx; // Ensure cleanup of `datum` if not already scheduled and obtain // a "by ref" pointer. let lv_datum = unpack_datum!(bcx, datum.to_lvalue_datum(bcx, "autoref", expr.id)); // Compute final type. Note that we are loose with the region and // mutability, since those things don't matter in trans. let referent_ty = lv_datum.ty; let ptr_ty = ty::mk_imm_rptr(bcx.tcx(), ty::ReStatic, referent_ty); // Get the pointer. let llref = lv_datum.to_llref(); // Construct the resulting datum, using what was the "by ref" // ValueRef of type `referent_ty` to be the "by value" ValueRef // of type `&referent_ty`. DatumBlock(bcx, Datum(llref, ptr_ty, RvalueExpr(Rvalue(ByValue)))) } fn auto_borrow_fn<'a>( bcx: &'a Block<'a>, adjusted_ty: ty::t, datum: Datum) -> DatumBlock<'a, Expr> { // Currently, all closure types are represented precisely the // same, so no runtime adjustment is required, but we still // must patchup the type. DatumBlock {bcx: bcx, datum: Datum {val: datum.val, ty: adjusted_ty, kind: datum.kind}} } fn auto_slice<'a>( bcx: &'a Block<'a>, autoderefs: uint, expr: &ast::Expr, datum: Datum) -> DatumBlock<'a, Expr> { // This is not the most efficient thing possible; since slices // are two words it'd be better if this were compiled in // 'dest' mode, but I can't find a nice way to structure the // code and keep it DRY that accommodates that use case at the // moment. let mut bcx = bcx; let tcx = bcx.tcx(); let unit_ty = ty::sequence_element_type(tcx, datum.ty); // Arrange cleanup, if not already done. This is needed in // case we are auto-slicing an owned vector or some such. let datum = unpack_datum!( bcx, datum.to_lvalue_datum(bcx, "auto_slice", expr.id)); let (bcx, base, len) = datum.get_vec_base_and_len(bcx, expr.span, expr.id, autoderefs+1); // this type may have a different region/mutability than the // real one, but it will have the same runtime representation let slice_ty = ty::mk_vec(tcx, ty::mt { ty: unit_ty, mutbl: ast::MutImmutable }, ty::vstore_slice(ty::ReStatic)); let scratch = rvalue_scratch_datum(bcx, slice_ty, "__adjust"); Store(bcx, base, GEPi(bcx, scratch.val, [0u, abi::slice_elt_base])); Store(bcx, len, GEPi(bcx, scratch.val, [0u, abi::slice_elt_len])); DatumBlock(bcx, scratch.to_expr_datum()) } fn add_env<'a>(bcx: &'a Block<'a>, expr: &ast::Expr, datum: Datum) -> DatumBlock<'a, Expr> { // This is not the most efficient thing possible; since closures // are two words it'd be better if this were compiled in // 'dest' mode, but I can't find a nice way to structure the // code and keep it DRY that accommodates that use case at the // moment. let tcx = bcx.tcx(); let closure_ty = expr_ty_adjusted(bcx, expr); debug!("add_env(closure_ty={})", closure_ty.repr(tcx)); let scratch = rvalue_scratch_datum(bcx, closure_ty, "__adjust"); let llfn = GEPi(bcx, scratch.val, [0u, abi::fn_field_code]); let llval = datum.to_llscalarish(bcx); Store(bcx, llval, llfn); let llenv = GEPi(bcx, scratch.val, [0u, abi::fn_field_box]); Store(bcx, base::null_env_ptr(bcx.ccx()), llenv); DatumBlock(bcx, scratch.to_expr_datum()) } fn auto_slice_and_ref<'a>( bcx: &'a Block<'a>, autoderefs: uint, expr: &ast::Expr, datum: Datum) -> DatumBlock<'a, Expr> { let DatumBlock { bcx, datum } = auto_slice(bcx, autoderefs, expr, datum); auto_ref(bcx, datum, expr) } fn auto_borrow_obj<'a>( mut bcx: &'a Block<'a>, autoderefs: uint, expr: &ast::Expr, source_datum: Datum) -> DatumBlock<'a, Expr> { let tcx = bcx.tcx(); let target_obj_ty = expr_ty_adjusted(bcx, expr); debug!("auto_borrow_obj(target={})", target_obj_ty.repr(tcx)); // Extract source store information let (source_store, source_mutbl) = match ty::get(source_datum.ty).sty { ty::ty_trait(_, _, s, m, _) => (s, m), _ => { bcx.sess().span_bug( expr.span, format!("auto_borrow_trait_obj expected a trait, found {}", source_datum.ty.repr(bcx.tcx()))); } }; // check if any borrowing is really needed or we could reuse // the source_datum instead match ty::get(target_obj_ty).sty { ty::ty_trait(_, _, ty::RegionTraitStore(target_scope), target_mutbl, _) => { if target_mutbl == ast::MutImmutable && target_mutbl == source_mutbl { match source_store { ty::RegionTraitStore(source_scope) => { if tcx.region_maps.is_subregion_of(target_scope, source_scope) { return DatumBlock { bcx: bcx, datum: source_datum }; } }, _ => {} }; } }, _ => {} } let scratch = rvalue_scratch_datum(bcx, target_obj_ty, "__auto_borrow_obj"); // Convert a @Object, ~Object, or &Object pair into an &Object pair. // Get a pointer to the source object, which is represented as // a (vtable, data) pair. let source_datum = unpack_datum!( bcx, source_datum.to_lvalue_datum(bcx, "auto_borrow_obj", expr.id)); let source_llval = source_datum.to_llref(); // Set the vtable field of the new pair let vtable_ptr = GEPi(bcx, source_llval, [0u, abi::trt_field_vtable]); let vtable = Load(bcx, vtable_ptr); Store(bcx, vtable, GEPi(bcx, scratch.val, [0u, abi::trt_field_vtable])); // Load the data for the source, which is either an @T, // ~T, or &T, depending on source_obj_ty. let source_data_ptr = GEPi(bcx, source_llval, [0u, abi::trt_field_box]); let target_data = match source_store { ty::BoxTraitStore(..) => { // For deref of @T, create a dummy datum and use the // datum's deref method. This is more work than just // calling GEPi ourselves, but it ensures that any // necessary rooting is performed. Note that we don't // know the type T, so just substitute `i8`-- it // doesn't really matter for our purposes right now. let source_ty = ty::mk_box(tcx, ty::mk_i8()); let source_datum = Datum(source_data_ptr, source_ty, LvalueExpr); let derefd_datum = unpack_datum!( bcx, deref_once(bcx, expr, source_datum, autoderefs)); derefd_datum.assert_lvalue(bcx).to_llref() } ty::UniqTraitStore(..) | ty::RegionTraitStore(..) => { Load(bcx, source_data_ptr) } }; Store(bcx, target_data, GEPi(bcx, scratch.val, [0u, abi::trt_field_box])); DatumBlock(bcx, scratch.to_expr_datum()) } } pub fn trans_to_lvalue<'a>(bcx: &'a Block<'a>, expr: &ast::Expr, name: &str) -> DatumBlock<'a, Lvalue> { /*! * Translates an expression in "lvalue" mode -- meaning that it * returns a reference to the memory that the expr represents. * * If this expression is an rvalue, this implies introducing a * temporary. In other words, something like `x().f` is * translated into roughly the equivalent of * * { tmp = x(); tmp.f } */ let mut bcx = bcx; let datum = unpack_datum!(bcx, trans(bcx, expr)); return datum.to_lvalue_datum(bcx, name, expr.id); } fn trans_unadjusted<'a>(bcx: &'a Block<'a>, expr: &ast::Expr) -> DatumBlock<'a, Expr> { /*! * A version of `trans` that ignores adjustments. You almost * certainly do not want to call this directly. */ let mut bcx = bcx; debug!("trans_unadjusted(expr={})", bcx.expr_to_str(expr)); let _indenter = indenter(); debuginfo::set_source_location(bcx.fcx, expr.id, expr.span); return match ty::expr_kind(bcx.tcx(), bcx.ccx().maps.method_map, expr) { ty::LvalueExpr | ty::RvalueDatumExpr => { let datum = unpack_datum!(bcx, { trans_datum_unadjusted(bcx, expr) }); DatumBlock {bcx: bcx, datum: datum} } ty::RvalueStmtExpr => { bcx = trans_rvalue_stmt_unadjusted(bcx, expr); nil(bcx, expr_ty(bcx, expr)) } ty::RvalueDpsExpr => { let ty = expr_ty(bcx, expr); if type_is_zero_size(bcx.ccx(), ty) { bcx = trans_rvalue_dps_unadjusted(bcx, expr, Ignore); nil(bcx, ty) } else { let scratch = rvalue_scratch_datum(bcx, ty, ""); bcx = trans_rvalue_dps_unadjusted( bcx, expr, SaveIn(scratch.val)); // Note: this is not obviously a good idea. It causes // immediate values to be loaded immediately after a // return from a call or other similar expression, // which in turn leads to alloca's having shorter // lifetimes and hence larger stack frames. However, // in turn it can lead to more register pressure. // Still, in practice it seems to increase // performance, since we have fewer problems with // morestack churn. let scratch = unpack_datum!( bcx, scratch.to_appropriate_datum(bcx)); DatumBlock(bcx, scratch.to_expr_datum()) } } }; fn nil<'a>(bcx: &'a Block<'a>, ty: ty::t) -> DatumBlock<'a, Expr> { let llval = C_undef(type_of::type_of(bcx.ccx(), ty)); let datum = immediate_rvalue(llval, ty); DatumBlock(bcx, datum.to_expr_datum()) } } fn trans_datum_unadjusted<'a>(bcx: &'a Block<'a>, expr: &ast::Expr) -> DatumBlock<'a, Expr> { let mut bcx = bcx; let fcx = bcx.fcx; let _icx = push_ctxt("trans_datum_unadjusted"); match expr.node { ast::ExprParen(e) => { trans(bcx, e) } ast::ExprPath(_) | ast::ExprSelf => { trans_def(bcx, expr, bcx.def(expr.id)) } ast::ExprField(base, ident, _) => { trans_rec_field(bcx, base, ident) } ast::ExprIndex(_, base, idx) => { trans_index(bcx, expr, base, idx) } ast::ExprVstore(contents, ast::ExprVstoreBox) => { fcx.push_ast_cleanup_scope(contents.id); let datum = unpack_datum!( bcx, tvec::trans_uniq_or_managed_vstore(bcx, heap_managed, expr, contents)); bcx = fcx.pop_and_trans_ast_cleanup_scope(bcx, contents.id); DatumBlock(bcx, datum) } ast::ExprVstore(contents, ast::ExprVstoreUniq) => { fcx.push_ast_cleanup_scope(contents.id); let datum = unpack_datum!( bcx, tvec::trans_uniq_or_managed_vstore(bcx, heap_exchange, expr, contents)); bcx = fcx.pop_and_trans_ast_cleanup_scope(bcx, contents.id); DatumBlock(bcx, datum) } ast::ExprBox(_, contents) => { // Special case for `~T`. (The other case, for GC, is handled in // `trans_rvalue_dps_unadjusted`.) let box_ty = expr_ty(bcx, expr); let contents_ty = expr_ty(bcx, contents); let heap = heap_exchange; return trans_boxed_expr(bcx, box_ty, contents, contents_ty, heap) } ast::ExprLit(lit) => { trans_immediate_lit(bcx, expr, *lit) } ast::ExprBinary(_, op, lhs, rhs) => { // if overloaded, would be RvalueDpsExpr { let method_map = bcx.ccx().maps.method_map.borrow(); assert!(!method_map.get().contains_key(&expr.id)); } trans_binary(bcx, expr, op, lhs, rhs) } ast::ExprUnary(_, ast::UnDeref, base) => { let basedatum = unpack_datum!(bcx, trans(bcx, base)); deref_once(bcx, expr, basedatum, 0) } ast::ExprUnary(_, op, x) => { trans_unary_datum(bcx, expr, op, x) } ast::ExprAddrOf(_, x) => { trans_addr_of(bcx, expr, x) } ast::ExprCast(val, _) => { // Datum output mode means this is a scalar cast: trans_imm_cast(bcx, val, expr.id) } ast::ExprLogLevel => { trans_log_level(bcx) } _ => { bcx.tcx().sess.span_bug( expr.span, format!("trans_rvalue_datum_unadjusted reached \ fall-through case: {:?}", expr.node)); } } } fn trans_rec_field<'a>(bcx: &'a Block<'a>, base: &ast::Expr, field: ast::Ident) -> DatumBlock<'a, Expr> { //! Translates `base.field`. let mut bcx = bcx; let _icx = push_ctxt("trans_rec_field"); let base_datum = unpack_datum!(bcx, trans_to_lvalue(bcx, base, "field")); let repr = adt::represent_type(bcx.ccx(), base_datum.ty); with_field_tys(bcx.tcx(), base_datum.ty, None, |discr, field_tys| { let ix = ty::field_idx_strict(bcx.tcx(), field.name, field_tys); let d = base_datum.get_element( field_tys[ix].mt.ty, |srcval| adt::trans_field_ptr(bcx, repr, srcval, discr, ix)); DatumBlock { datum: d.to_expr_datum(), bcx: bcx } }) } fn trans_index<'a>(bcx: &'a Block<'a>, index_expr: &ast::Expr, base: &ast::Expr, idx: &ast::Expr) -> DatumBlock<'a, Expr> { //! Translates `base[idx]`. let _icx = push_ctxt("trans_index"); let ccx = bcx.ccx(); let mut bcx = bcx; let base_datum = unpack_datum!(bcx, trans_to_lvalue(bcx, base, "index")); // Translate index expression and cast to a suitable LLVM integer. // Rust is less strict than LLVM in this regard. let ix_datum = unpack_datum!(bcx, trans(bcx, idx)); let ix_val = ix_datum.to_llscalarish(bcx); let ix_size = machine::llbitsize_of_real(bcx.ccx(), val_ty(ix_val)); let int_size = machine::llbitsize_of_real(bcx.ccx(), ccx.int_type); let ix_val = { if ix_size < int_size { if ty::type_is_signed(expr_ty(bcx, idx)) { SExt(bcx, ix_val, ccx.int_type) } else { ZExt(bcx, ix_val, ccx.int_type) } } else if ix_size > int_size { Trunc(bcx, ix_val, ccx.int_type) } else { ix_val } }; let vt = tvec::vec_types(bcx, base_datum.ty); base::maybe_name_value(bcx.ccx(), vt.llunit_size, "unit_sz"); let (bcx, base, len) = base_datum.get_vec_base_and_len(bcx, index_expr.span, index_expr.id, 0); debug!("trans_index: base {}", bcx.val_to_str(base)); debug!("trans_index: len {}", bcx.val_to_str(len)); let bounds_check = ICmp(bcx, lib::llvm::IntUGE, ix_val, len); let expect = ccx.intrinsics.get_copy(&("llvm.expect.i1")); let expected = Call(bcx, expect, [bounds_check, C_i1(false)], []); let bcx = with_cond(bcx, expected, |bcx| { controlflow::trans_fail_bounds_check(bcx, index_expr.span, ix_val, len) }); let elt = InBoundsGEP(bcx, base, [ix_val]); let elt = PointerCast(bcx, elt, vt.llunit_ty.ptr_to()); DatumBlock(bcx, Datum(elt, vt.unit_ty, LvalueExpr)) } fn trans_def<'a>(bcx: &'a Block<'a>, ref_expr: &ast::Expr, def: ast::Def) -> DatumBlock<'a, Expr> { //! Translates a reference to a path. let _icx = push_ctxt("trans_def_lvalue"); match def { ast::DefFn(..) | ast::DefStaticMethod(..) => { trans_def_fn_unadjusted(bcx, ref_expr, def) } ast::DefStatic(did, _) => { let const_ty = expr_ty(bcx, ref_expr); fn get_did(ccx: @CrateContext, did: ast::DefId) -> ast::DefId { if did.crate != ast::LOCAL_CRATE { inline::maybe_instantiate_inline(ccx, did) } else { did } } fn get_val<'a>(bcx: &'a Block<'a>, did: ast::DefId, const_ty: ty::t) -> ValueRef { // For external constants, we don't inline. if did.crate == ast::LOCAL_CRATE { // The LLVM global has the type of its initializer, // which may not be equal to the enum's type for // non-C-like enums. let val = base::get_item_val(bcx.ccx(), did.node); let pty = type_of::type_of(bcx.ccx(), const_ty).ptr_to(); PointerCast(bcx, val, pty) } else { { let extern_const_values = bcx.ccx().extern_const_values.borrow(); match extern_const_values.get().find(&did) { None => {} // Continue. Some(llval) => { return *llval; } } } unsafe { let llty = type_of::type_of(bcx.ccx(), const_ty); let symbol = csearch::get_symbol( bcx.ccx().sess.cstore, did); let llval = symbol.with_c_str(|buf| { llvm::LLVMAddGlobal(bcx.ccx().llmod, llty.to_ref(), buf) }); let mut extern_const_values = bcx.ccx().extern_const_values.borrow_mut(); extern_const_values.get().insert(did, llval); llval } } } let did = get_did(bcx.ccx(), did); let val = get_val(bcx, did, const_ty); DatumBlock(bcx, Datum(val, const_ty, LvalueExpr)) } _ => { DatumBlock(bcx, trans_local_var(bcx, def).to_expr_datum()) } } } fn trans_rvalue_stmt_unadjusted<'a>(bcx: &'a Block<'a>, expr: &ast::Expr) -> &'a Block<'a> { let mut bcx = bcx; let _icx = push_ctxt("trans_rvalue_stmt"); if bcx.unreachable.get() { return bcx; } match expr.node { ast::ExprParen(e) => { trans_into(bcx, e, Ignore) } ast::ExprBreak(label_opt) => { controlflow::trans_break(bcx, expr.id, label_opt) } ast::ExprAgain(label_opt) => { controlflow::trans_cont(bcx, expr.id, label_opt) } ast::ExprRet(ex) => { controlflow::trans_ret(bcx, ex) } ast::ExprWhile(cond, body) => { controlflow::trans_while(bcx, expr.id, cond, body) } ast::ExprLoop(body, _) => { controlflow::trans_loop(bcx, expr.id, body) } ast::ExprAssign(dst, src) => { let src_datum = unpack_datum!(bcx, trans(bcx, src)); let dst_datum = unpack_datum!(bcx, trans_to_lvalue(bcx, dst, "assign")); if ty::type_needs_drop(bcx.tcx(), dst_datum.ty) { // If there are destructors involved, make sure we // are copying from an rvalue, since that cannot possible // alias an lvalue. We are concerned about code like: // // a = a // // but also // // a = a.b // // where e.g. a : Option and a.b : // Option. In that case, freeing `a` before the // assignment may also free `a.b`! // // We could avoid this intermediary with some analysis // to determine whether `dst` may possibly own `src`. let src_datum = unpack_datum!( bcx, src_datum.to_rvalue_datum(bcx, "ExprAssign")); bcx = glue::drop_ty(bcx, dst_datum.val, dst_datum.ty); src_datum.store_to(bcx, dst_datum.val) } else { src_datum.store_to(bcx, dst_datum.val) } } ast::ExprAssignOp(callee_id, op, dst, src) => { trans_assign_op(bcx, expr, callee_id, op, dst, src) } ast::ExprInlineAsm(ref a) => { asm::trans_inline_asm(bcx, a) } _ => { bcx.tcx().sess.span_bug( expr.span, format!("trans_rvalue_stmt_unadjusted reached \ fall-through case: {:?}", expr.node)); } } } fn trans_rvalue_dps_unadjusted<'a>(bcx: &'a Block<'a>, expr: &ast::Expr, dest: Dest) -> &'a Block<'a> { let _icx = push_ctxt("trans_rvalue_dps_unadjusted"); let mut bcx = bcx; let tcx = bcx.tcx(); let fcx = bcx.fcx; match expr.node { ast::ExprParen(e) => { return trans_into(bcx, e, dest); } ast::ExprPath(_) | ast::ExprSelf => { return trans_def_dps_unadjusted(bcx, expr, bcx.def(expr.id), dest); } ast::ExprIf(cond, thn, els) => { return controlflow::trans_if(bcx, expr.id, cond, thn, els, dest); } ast::ExprMatch(discr, ref arms) => { return _match::trans_match(bcx, expr, discr, *arms, dest); } ast::ExprBlock(blk) => { controlflow::trans_block(bcx, blk, dest) } ast::ExprStruct(_, ref fields, base) => { return trans_rec_or_struct(bcx, (*fields), base, expr.span, expr.id, dest); } ast::ExprTup(ref args) => { let repr = adt::represent_type(bcx.ccx(), expr_ty(bcx, expr)); let numbered_fields: ~[(uint, @ast::Expr)] = args.iter().enumerate().map(|(i, arg)| (i, *arg)).collect(); return trans_adt(bcx, repr, 0, numbered_fields, None, dest); } ast::ExprLit(lit) => { match lit.node { ast::LitStr(s, _) => { return tvec::trans_lit_str(bcx, expr, s, dest); } _ => { bcx.tcx() .sess .span_bug(expr.span, "trans_rvalue_dps_unadjusted shouldn't be \ translating this type of literal") } } } ast::ExprVstore(contents, ast::ExprVstoreSlice) | ast::ExprVstore(contents, ast::ExprVstoreMutSlice) => { fcx.push_ast_cleanup_scope(contents.id); bcx = tvec::trans_slice_vstore(bcx, expr, contents, dest); return fcx.pop_and_trans_ast_cleanup_scope(bcx, contents.id); } ast::ExprVec(..) | ast::ExprRepeat(..) => { return tvec::trans_fixed_vstore(bcx, expr, expr, dest); } ast::ExprFnBlock(decl, body) | ast::ExprProc(decl, body) => { let expr_ty = expr_ty(bcx, expr); let sigil = ty::ty_closure_sigil(expr_ty); debug!("translating block function {} with type {}", expr_to_str(expr, tcx.sess.intr()), expr_ty.repr(tcx)); return closure::trans_expr_fn(bcx, sigil, decl, body, expr.id, expr.id, dest); } ast::ExprDoBody(blk) => { return trans_into(bcx, blk, dest); } ast::ExprCall(f, ref args, _) => { return callee::trans_call( bcx, expr, f, callee::ArgExprs(*args), expr.id, dest); } ast::ExprMethodCall(callee_id, rcvr, _, _, ref args, _) => { return callee::trans_method_call(bcx, expr, callee_id, rcvr, callee::ArgExprs(*args), dest); } ast::ExprBinary(callee_id, _, lhs, rhs) => { // if not overloaded, would be RvalueDatumExpr return trans_overloaded_op(bcx, expr, callee_id, lhs, ~[rhs], expr_ty(bcx, expr), dest); } ast::ExprUnary(callee_id, _, subexpr) => { // if not overloaded, would be RvalueDatumExpr return trans_overloaded_op(bcx, expr, callee_id, subexpr, ~[], expr_ty(bcx, expr), dest); } ast::ExprIndex(callee_id, base, idx) => { // if not overloaded, would be RvalueDatumExpr return trans_overloaded_op(bcx, expr, callee_id, base, ~[idx], expr_ty(bcx, expr), dest); } ast::ExprCast(val, _) => { // DPS output mode means this is a trait cast: match ty::get(node_id_type(bcx, expr.id)).sty { ty::ty_trait(..) => { let datum = unpack_datum!(bcx, trans(bcx, val)); return meth::trans_trait_cast(bcx, datum, expr.id, dest); } _ => { bcx.tcx().sess.span_bug(expr.span, "expr_cast of non-trait"); } } } ast::ExprAssignOp(callee_id, op, dst, src) => { return trans_assign_op(bcx, expr, callee_id, op, dst, src); } ast::ExprBox(_, contents) => { // Special case for `Gc` for now. The other case, for unique // pointers, is handled in `trans_rvalue_datum_unadjusted`. return trans_gc(bcx, expr, contents, dest) } _ => { bcx.tcx().sess.span_bug( expr.span, format!("trans_rvalue_dps_unadjusted reached fall-through case: {:?}", expr.node)); } } } fn trans_def_dps_unadjusted<'a>( bcx: &'a Block<'a>, ref_expr: &ast::Expr, def: ast::Def, dest: Dest) -> &'a Block<'a> { let _icx = push_ctxt("trans_def_dps_unadjusted"); let ccx = bcx.ccx(); let lldest = match dest { SaveIn(lldest) => lldest, Ignore => { return bcx; } }; match def { ast::DefVariant(tid, vid, _) => { let variant_info = ty::enum_variant_with_id(ccx.tcx, tid, vid); if variant_info.args.len() > 0u { // N-ary variant. let fn_data = callee::trans_fn_ref(bcx, vid, ref_expr.id); Store(bcx, fn_data.llfn, lldest); return bcx; } else { // Nullary variant. let ty = expr_ty(bcx, ref_expr); let repr = adt::represent_type(ccx, ty); adt::trans_start_init(bcx, repr, lldest, variant_info.disr_val); return bcx; } } ast::DefStruct(def_id) => { let ty = expr_ty(bcx, ref_expr); match ty::get(ty).sty { ty::ty_struct(did, _) if ty::has_dtor(ccx.tcx, did) => { let repr = adt::represent_type(ccx, ty); adt::trans_start_init(bcx, repr, lldest, 0); } ty::ty_bare_fn(..) => { let fn_data = callee::trans_fn_ref(bcx, def_id, ref_expr.id); Store(bcx, fn_data.llfn, lldest); } _ => () } return bcx; } _ => { bcx.tcx().sess.span_bug(ref_expr.span, format!( "Non-DPS def {:?} referened by {}", def, bcx.node_id_to_str(ref_expr.id))); } } } fn trans_def_fn_unadjusted<'a>(bcx: &'a Block<'a>, ref_expr: &ast::Expr, def: ast::Def) -> DatumBlock<'a, Expr> { let _icx = push_ctxt("trans_def_datum_unadjusted"); let fn_data = match def { ast::DefFn(did, _) | ast::DefStaticMethod(did, ast::FromImpl(_), _) => { callee::trans_fn_ref(bcx, did, ref_expr.id) } ast::DefStaticMethod(impl_did, ast::FromTrait(trait_did), _) => { meth::trans_static_method_callee(bcx, impl_did, trait_did, ref_expr.id) } _ => { bcx.tcx().sess.span_bug(ref_expr.span, format!( "trans_def_fn_unadjusted invoked on: {:?} for {}", def, ref_expr.repr(bcx.tcx()))); } }; let fn_ty = expr_ty(bcx, ref_expr); DatumBlock(bcx, Datum(fn_data.llfn, fn_ty, RvalueExpr(Rvalue(ByValue)))) } pub fn trans_local_var<'a>(bcx: &'a Block<'a>, def: ast::Def) -> Datum { /*! * Translates a reference to a local variable or argument. * This always results in an lvalue datum. */ let _icx = push_ctxt("trans_local_var"); return match def { ast::DefUpvar(nid, _, _, _) => { // Can't move upvars, so this is never a ZeroMemLastUse. let local_ty = node_id_type(bcx, nid); let llupvars = bcx.fcx.llupvars.borrow(); match llupvars.get().find(&nid) { Some(&val) => Datum(val, local_ty, Lvalue), None => { bcx.sess().bug(format!( "trans_local_var: no llval for upvar {:?} found", nid)); } } } ast::DefArg(nid, _) => { let llargs = bcx.fcx.llargs.borrow(); take_local(bcx, llargs.get(), nid) } ast::DefLocal(nid, _) | ast::DefBinding(nid, _) => { let lllocals = bcx.fcx.lllocals.borrow(); take_local(bcx, lllocals.get(), nid) } ast::DefSelf(nid, _) => { let self_info = match bcx.fcx.llself.get() { Some(self_info) => self_info, None => { bcx.sess().bug(format!( "trans_local_var: reference to self \ out of context with id {:?}", nid)); } }; debug!("def_self() reference, self_info.ty={}", self_info.ty.repr(bcx.tcx())); self_info } _ => { bcx.sess().unimpl(format!( "unsupported def type in trans_local_var: {:?}", def)); } }; fn take_local<'a>(bcx: &'a Block<'a>, table: &HashMap>, nid: ast::NodeId) -> Datum { let datum = match table.find(&nid) { Some(&v) => v, None => { bcx.sess().bug(format!( "trans_local_var: no datum for local/arg {:?} found", nid)); } }; debug!("take_local(nid={:?}, v={}, ty={})", nid, bcx.val_to_str(datum.val), bcx.ty_to_str(datum.ty)); datum } } pub fn with_field_tys(tcx: ty::ctxt, ty: ty::t, node_id_opt: Option, op: |ty::Disr, (&[ty::field])| -> R) -> R { /*! * Helper for enumerating the field types of structs, enums, or records. * The optional node ID here is the node ID of the path identifying the enum * variant in use. If none, this cannot possibly an enum variant (so, if it * is and `node_id_opt` is none, this function fails). */ match ty::get(ty).sty { ty::ty_struct(did, ref substs) => { op(0, struct_fields(tcx, did, substs)) } ty::ty_enum(_, ref substs) => { // We want the *variant* ID here, not the enum ID. match node_id_opt { None => { tcx.sess.bug(format!( "cannot get field types from the enum type {} \ without a node ID", ty.repr(tcx))); } Some(node_id) => { let opt_def = { let def_map = tcx.def_map.borrow(); def_map.get().get_copy(&node_id) }; match opt_def { ast::DefVariant(enum_id, variant_id, _) => { let variant_info = ty::enum_variant_with_id( tcx, enum_id, variant_id); op(variant_info.disr_val, struct_fields(tcx, variant_id, substs)) } _ => { tcx.sess.bug("resolve didn't map this expr to a \ variant ID") } } } } } _ => { tcx.sess.bug(format!( "cannot get field types from the type {}", ty.repr(tcx))); } } } fn trans_rec_or_struct<'a>( bcx: &'a Block<'a>, fields: &[ast::Field], base: Option<@ast::Expr>, expr_span: codemap::Span, id: ast::NodeId, dest: Dest) -> &'a Block<'a> { let _icx = push_ctxt("trans_rec"); let bcx = bcx; let ty = node_id_type(bcx, id); let tcx = bcx.tcx(); with_field_tys(tcx, ty, Some(id), |discr, field_tys| { let mut need_base = vec::from_elem(field_tys.len(), true); let numbered_fields = fields.map(|field| { let opt_pos = field_tys.iter().position(|field_ty| field_ty.ident.name == field.ident.node.name); match opt_pos { Some(i) => { need_base[i] = false; (i, field.expr) } None => { tcx.sess.span_bug(field.span, "Couldn't find field in struct type") } } }); let optbase = match base { Some(base_expr) => { let mut leftovers = ~[]; for (i, b) in need_base.iter().enumerate() { if *b { leftovers.push((i, field_tys[i].mt.ty)) } } Some(StructBaseInfo {expr: base_expr, fields: leftovers }) } None => { if need_base.iter().any(|b| *b) { tcx.sess.span_bug(expr_span, "missing fields and no base expr") } None } }; let repr = adt::represent_type(bcx.ccx(), ty); trans_adt(bcx, repr, discr, numbered_fields, optbase, dest) }) } /** * Information that `trans_adt` needs in order to fill in the fields * of a struct copied from a base struct (e.g., from an expression * like `Foo { a: b, ..base }`. * * Note that `fields` may be empty; the base expression must always be * evaluated for side-effects. */ struct StructBaseInfo { /// The base expression; will be evaluated after all explicit fields. expr: @ast::Expr, /// The indices of fields to copy paired with their types. fields: ~[(uint, ty::t)] } /** * Constructs an ADT instance: * * - `fields` should be a list of field indices paired with the * expression to store into that field. The initializers will be * evaluated in the order specified by `fields`. * * - `optbase` contains information on the base struct (if any) from * which remaining fields are copied; see comments on `StructBaseInfo`. */ fn trans_adt<'a>( bcx: &'a Block<'a>, repr: &adt::Repr, discr: ty::Disr, fields: &[(uint, @ast::Expr)], optbase: Option, dest: Dest) -> &'a Block<'a> { let _icx = push_ctxt("trans_adt"); let fcx = bcx.fcx; let mut bcx = bcx; let addr = match dest { Ignore => { for &(_i, e) in fields.iter() { bcx = trans_into(bcx, e, Ignore); } for sbi in optbase.iter() { // FIXME #7261: this moves entire base, not just certain fields bcx = trans_into(bcx, sbi.expr, Ignore); } return bcx; } SaveIn(pos) => pos }; // This scope holds intermediates that must be cleaned should // failure occur before the ADT as a whole is ready. let custom_cleanup_scope = fcx.push_custom_cleanup_scope(); adt::trans_start_init(bcx, repr, addr, discr); for &(i, e) in fields.iter() { let dest = adt::trans_field_ptr(bcx, repr, addr, discr, i); let e_ty = expr_ty_adjusted(bcx, e); bcx = trans_into(bcx, e, SaveIn(dest)); fcx.schedule_drop_mem(cleanup::CustomScope(custom_cleanup_scope), dest, e_ty); } for base in optbase.iter() { // FIXME #6573: is it sound to use the destination's repr on the base? // And, would it ever be reasonable to be here with discr != 0? let base_datum = unpack_datum!(bcx, trans_to_lvalue(bcx, base.expr, "base")); for &(i, t) in base.fields.iter() { let datum = base_datum.get_element( t, |srcval| adt::trans_field_ptr(bcx, repr, srcval, discr, i)); let dest = adt::trans_field_ptr(bcx, repr, addr, discr, i); bcx = datum.store_to(bcx, dest); } } fcx.pop_custom_cleanup_scope(custom_cleanup_scope); return bcx; } fn trans_immediate_lit<'a>(bcx: &'a Block<'a>, expr: &ast::Expr, lit: ast::Lit) -> DatumBlock<'a, Expr> { // must not be a string constant, that is a RvalueDpsExpr let _icx = push_ctxt("trans_immediate_lit"); let ty = expr_ty(bcx, expr); let v = consts::const_lit(bcx.ccx(), expr, lit); immediate_rvalue_bcx(bcx, v, ty).to_expr_datumblock() } fn trans_unary_datum<'a>( bcx: &'a Block<'a>, un_expr: &ast::Expr, op: ast::UnOp, sub_expr: &ast::Expr) -> DatumBlock<'a, Expr> { let mut bcx = bcx; let _icx = push_ctxt("trans_unary_datum"); // if deref, would be LvalueExpr assert!(op != ast::UnDeref); // if overloaded, would be RvalueDpsExpr { let method_map = bcx.ccx().maps.method_map.borrow(); assert!(!method_map.get().contains_key(&un_expr.id)); } let un_ty = expr_ty(bcx, un_expr); let sub_ty = expr_ty(bcx, sub_expr); return match op { ast::UnNot => { let datum = unpack_datum!(bcx, trans(bcx, sub_expr)); let llresult = if ty::type_is_bool(un_ty) { let val = datum.to_llscalarish(bcx); let llcond = ICmp(bcx, lib::llvm::IntEQ, val, C_bool(false)); Select(bcx, llcond, C_bool(true), C_bool(false)) } else { // Note: `Not` is bitwise, not suitable for logical not. Not(bcx, datum.to_llscalarish(bcx)) }; immediate_rvalue_bcx(bcx, llresult, un_ty).to_expr_datumblock() } ast::UnNeg => { let datum = unpack_datum!(bcx, trans(bcx, sub_expr)); let val = datum.to_llscalarish(bcx); let llneg = { if ty::type_is_fp(un_ty) { FNeg(bcx, val) } else { Neg(bcx, val) } }; immediate_rvalue_bcx(bcx, llneg, un_ty).to_expr_datumblock() } ast::UnBox => { trans_boxed_expr(bcx, un_ty, sub_expr, sub_ty, heap_managed) } ast::UnUniq => { trans_boxed_expr(bcx, un_ty, sub_expr, sub_ty, heap_exchange) } ast::UnDeref => { bcx.sess().bug("deref expressions should have been \ translated using trans_lvalue(), not \ trans_unary_datum()") } }; } fn trans_boxed_expr<'a>(bcx: &'a Block<'a>, box_ty: ty::t, contents: &ast::Expr, contents_ty: ty::t, heap: heap) -> DatumBlock<'a, Expr> { let _icx = push_ctxt("trans_boxed_expr"); let fcx = bcx.fcx; if heap == heap_exchange { let llty = type_of::type_of(bcx.ccx(), contents_ty); let size = llsize_of(bcx.ccx(), llty); let Result { bcx: bcx, val: val } = malloc_raw_dyn(bcx, contents_ty, heap_exchange, size); let custom_cleanup_scope = fcx.push_custom_cleanup_scope(); fcx.schedule_free_value(cleanup::CustomScope(custom_cleanup_scope), val, heap_exchange); let bcx = trans_into(bcx, contents, SaveIn(val)); fcx.pop_custom_cleanup_scope(custom_cleanup_scope); immediate_rvalue_bcx(bcx, val, box_ty).to_expr_datumblock() } else { let base::MallocResult { bcx, smart_ptr: bx, body } = base::malloc_general(bcx, contents_ty, heap); let custom_cleanup_scope = fcx.push_custom_cleanup_scope(); fcx.schedule_free_value(cleanup::CustomScope(custom_cleanup_scope), bx, heap); let bcx = trans_into(bcx, contents, SaveIn(body)); fcx.pop_custom_cleanup_scope(custom_cleanup_scope); immediate_rvalue_bcx(bcx, bx, box_ty).to_expr_datumblock() } } fn trans_addr_of<'a>(bcx: &'a Block<'a>, expr: &ast::Expr, subexpr: &ast::Expr) -> DatumBlock<'a, Expr> { let _icx = push_ctxt("trans_addr_of"); let mut bcx = bcx; let sub_datum = unpack_datum!(bcx, trans_to_lvalue(bcx, subexpr, "addr_of")); let ty = expr_ty(bcx, expr); return immediate_rvalue_bcx(bcx, sub_datum.val, ty).to_expr_datumblock(); } fn trans_gc<'a>(mut bcx: &'a Block<'a>, expr: &ast::Expr, contents: &ast::Expr, dest: Dest) -> &'a Block<'a> { let contents_ty = expr_ty(bcx, contents); let box_ty = ty::mk_box(bcx.tcx(), contents_ty); let expr_ty = expr_ty(bcx, expr); let addr = match dest { Ignore => { return trans_boxed_expr(bcx, box_ty, contents, contents_ty, heap_managed).bcx } SaveIn(addr) => addr, }; let repr = adt::represent_type(bcx.ccx(), expr_ty); adt::trans_start_init(bcx, repr, addr, 0); let field_dest = adt::trans_field_ptr(bcx, repr, addr, 0, 0); let contents_datum = unpack_datum!(bcx, trans_boxed_expr(bcx, box_ty, contents, contents_ty, heap_managed)); bcx = contents_datum.store_to(bcx, field_dest); // Next, wrap it up in the struct. bcx } // Important to get types for both lhs and rhs, because one might be _|_ // and the other not. fn trans_eager_binop<'a>( bcx: &'a Block<'a>, binop_expr: &ast::Expr, binop_ty: ty::t, op: ast::BinOp, lhs_t: ty::t, lhs: ValueRef, rhs_t: ty::t, rhs: ValueRef) -> DatumBlock<'a, Expr> { let _icx = push_ctxt("trans_eager_binop"); let mut intype = { if ty::type_is_bot(lhs_t) { rhs_t } else { lhs_t } }; let tcx = bcx.tcx(); if ty::type_is_simd(tcx, intype) { intype = ty::simd_type(tcx, intype); } let is_float = ty::type_is_fp(intype); let signed = ty::type_is_signed(intype); let rhs = base::cast_shift_expr_rhs(bcx, op, lhs, rhs); let mut bcx = bcx; let val = match op { ast::BiAdd => { if is_float { FAdd(bcx, lhs, rhs) } else { Add(bcx, lhs, rhs) } } ast::BiSub => { if is_float { FSub(bcx, lhs, rhs) } else { Sub(bcx, lhs, rhs) } } ast::BiMul => { if is_float { FMul(bcx, lhs, rhs) } else { Mul(bcx, lhs, rhs) } } ast::BiDiv => { if is_float { FDiv(bcx, lhs, rhs) } else { // Only zero-check integers; fp /0 is NaN bcx = base::fail_if_zero(bcx, binop_expr.span, op, rhs, rhs_t); if signed { SDiv(bcx, lhs, rhs) } else { UDiv(bcx, lhs, rhs) } } } ast::BiRem => { if is_float { FRem(bcx, lhs, rhs) } else { // Only zero-check integers; fp %0 is NaN bcx = base::fail_if_zero(bcx, binop_expr.span, op, rhs, rhs_t); if signed { SRem(bcx, lhs, rhs) } else { URem(bcx, lhs, rhs) } } } ast::BiBitOr => Or(bcx, lhs, rhs), ast::BiBitAnd => And(bcx, lhs, rhs), ast::BiBitXor => Xor(bcx, lhs, rhs), ast::BiShl => Shl(bcx, lhs, rhs), ast::BiShr => { if signed { AShr(bcx, lhs, rhs) } else { LShr(bcx, lhs, rhs) } } ast::BiEq | ast::BiNe | ast::BiLt | ast::BiGe | ast::BiLe | ast::BiGt => { if ty::type_is_bot(rhs_t) { C_bool(false) } else { if !ty::type_is_scalar(rhs_t) { bcx.tcx().sess.span_bug(binop_expr.span, "non-scalar comparison"); } let cmpr = base::compare_scalar_types(bcx, lhs, rhs, rhs_t, op); bcx = cmpr.bcx; ZExt(bcx, cmpr.val, Type::i8()) } } _ => { bcx.tcx().sess.span_bug(binop_expr.span, "unexpected binop"); } }; immediate_rvalue_bcx(bcx, val, binop_ty).to_expr_datumblock() } // refinement types would obviate the need for this enum lazy_binop_ty { lazy_and, lazy_or, } fn trans_lazy_binop<'a>( bcx: &'a Block<'a>, binop_expr: &ast::Expr, op: lazy_binop_ty, a: &ast::Expr, b: &ast::Expr) -> DatumBlock<'a, Expr> { let _icx = push_ctxt("trans_lazy_binop"); let binop_ty = expr_ty(bcx, binop_expr); let fcx = bcx.fcx; let DatumBlock {bcx: past_lhs, datum: lhs} = trans(bcx, a); let lhs = lhs.to_llscalarish(past_lhs); if past_lhs.unreachable.get() { return immediate_rvalue_bcx(past_lhs, lhs, binop_ty).to_expr_datumblock(); } let join = fcx.new_id_block("join", binop_expr.id); let before_rhs = fcx.new_id_block("before_rhs", b.id); let lhs_i1 = bool_to_i1(past_lhs, lhs); match op { lazy_and => CondBr(past_lhs, lhs_i1, before_rhs.llbb, join.llbb), lazy_or => CondBr(past_lhs, lhs_i1, join.llbb, before_rhs.llbb) } let DatumBlock {bcx: past_rhs, datum: rhs} = trans(before_rhs, b); let rhs = rhs.to_llscalarish(past_rhs); if past_rhs.unreachable.get() { return immediate_rvalue_bcx(join, lhs, binop_ty).to_expr_datumblock(); } Br(past_rhs, join.llbb); let phi = Phi(join, Type::bool(), [lhs, rhs], [past_lhs.llbb, past_rhs.llbb]); return immediate_rvalue_bcx(join, phi, binop_ty).to_expr_datumblock(); } fn trans_binary<'a>( bcx: &'a Block<'a>, binop_expr: &ast::Expr, op: ast::BinOp, lhs: &ast::Expr, rhs: &ast::Expr) -> DatumBlock<'a, Expr> { let _icx = push_ctxt("trans_binary"); let ccx = bcx.ccx(); match op { ast::BiAnd => { trans_lazy_binop(bcx, binop_expr, lazy_and, lhs, rhs) } ast::BiOr => { trans_lazy_binop(bcx, binop_expr, lazy_or, lhs, rhs) } _ => { let mut bcx = bcx; let lhs_datum = unpack_datum!(bcx, trans(bcx, lhs)); let rhs_datum = unpack_datum!(bcx, trans(bcx, rhs)); let binop_ty = expr_ty(bcx, binop_expr); debug!("trans_binary (expr {}): lhs_datum={}", binop_expr.id, lhs_datum.to_str(ccx)); let lhs_ty = lhs_datum.ty; let lhs = lhs_datum.to_llscalarish(bcx); debug!("trans_binary (expr {}): rhs_datum={}", binop_expr.id, rhs_datum.to_str(ccx)); let rhs_ty = rhs_datum.ty; let rhs = rhs_datum.to_llscalarish(bcx); trans_eager_binop(bcx, binop_expr, binop_ty, op, lhs_ty, lhs, rhs_ty, rhs) } } } fn trans_overloaded_op<'a>( bcx: &'a Block<'a>, expr: &ast::Expr, callee_id: ast::NodeId, rcvr: &ast::Expr, args: ~[@ast::Expr], ret_ty: ty::t, dest: Dest) -> &'a Block<'a> { let origin = { let method_map = bcx.ccx().maps.method_map.borrow(); method_map.get().get_copy(&expr.id) }; let fty = node_id_type(bcx, callee_id); callee::trans_call_inner(bcx, Some(expr_info(expr)), fty, ret_ty, |bcx, arg_cleanup_scope| { meth::trans_method_callee(bcx, callee_id, rcvr, origin, arg_cleanup_scope) }, callee::ArgExprs(args), Some(dest), DoAutorefArg).bcx } fn int_cast(bcx: &Block, lldsttype: Type, llsrctype: Type, llsrc: ValueRef, signed: bool) -> ValueRef { let _icx = push_ctxt("int_cast"); unsafe { let srcsz = llvm::LLVMGetIntTypeWidth(llsrctype.to_ref()); let dstsz = llvm::LLVMGetIntTypeWidth(lldsttype.to_ref()); return if dstsz == srcsz { BitCast(bcx, llsrc, lldsttype) } else if srcsz > dstsz { TruncOrBitCast(bcx, llsrc, lldsttype) } else if signed { SExtOrBitCast(bcx, llsrc, lldsttype) } else { ZExtOrBitCast(bcx, llsrc, lldsttype) }; } } fn float_cast(bcx: &Block, lldsttype: Type, llsrctype: Type, llsrc: ValueRef) -> ValueRef { let _icx = push_ctxt("float_cast"); let srcsz = llsrctype.float_width(); let dstsz = lldsttype.float_width(); return if dstsz > srcsz { FPExt(bcx, llsrc, lldsttype) } else if srcsz > dstsz { FPTrunc(bcx, llsrc, lldsttype) } else { llsrc }; } #[deriving(Eq)] pub enum cast_kind { cast_pointer, cast_integral, cast_float, cast_enum, cast_other, } pub fn cast_type_kind(t: ty::t) -> cast_kind { match ty::get(t).sty { ty::ty_char => cast_integral, ty::ty_float(..) => cast_float, ty::ty_ptr(..) => cast_pointer, ty::ty_rptr(..) => cast_pointer, ty::ty_bare_fn(..) => cast_pointer, ty::ty_int(..) => cast_integral, ty::ty_uint(..) => cast_integral, ty::ty_bool => cast_integral, ty::ty_enum(..) => cast_enum, _ => cast_other } } fn trans_imm_cast<'a>(bcx: &'a Block<'a>, expr: &ast::Expr, id: ast::NodeId) -> DatumBlock<'a, Expr> { let _icx = push_ctxt("trans_cast"); let mut bcx = bcx; let ccx = bcx.ccx(); let t_in = expr_ty(bcx, expr); let t_out = node_id_type(bcx, id); let k_in = cast_type_kind(t_in); let k_out = cast_type_kind(t_out); let s_in = k_in == cast_integral && ty::type_is_signed(t_in); let ll_t_in = type_of::type_of(ccx, t_in); let ll_t_out = type_of::type_of(ccx, t_out); // Convert the value to be cast into a ValueRef, either by-ref or // by-value as appropriate given its type: let datum = unpack_datum!(bcx, trans(bcx, expr)); let newval = match (k_in, k_out) { (cast_integral, cast_integral) => { let llexpr = datum.to_llscalarish(bcx); int_cast(bcx, ll_t_out, ll_t_in, llexpr, s_in) } (cast_float, cast_float) => { let llexpr = datum.to_llscalarish(bcx); float_cast(bcx, ll_t_out, ll_t_in, llexpr) } (cast_integral, cast_float) => { let llexpr = datum.to_llscalarish(bcx); if s_in { SIToFP(bcx, llexpr, ll_t_out) } else { UIToFP(bcx, llexpr, ll_t_out) } } (cast_float, cast_integral) => { let llexpr = datum.to_llscalarish(bcx); if ty::type_is_signed(t_out) { FPToSI(bcx, llexpr, ll_t_out) } else { FPToUI(bcx, llexpr, ll_t_out) } } (cast_integral, cast_pointer) => { let llexpr = datum.to_llscalarish(bcx); IntToPtr(bcx, llexpr, ll_t_out) } (cast_pointer, cast_integral) => { let llexpr = datum.to_llscalarish(bcx); PtrToInt(bcx, llexpr, ll_t_out) } (cast_pointer, cast_pointer) => { let llexpr = datum.to_llscalarish(bcx); PointerCast(bcx, llexpr, ll_t_out) } (cast_enum, cast_integral) | (cast_enum, cast_float) => { let mut bcx = bcx; let repr = adt::represent_type(ccx, t_in); let datum = unpack_datum!( bcx, datum.to_lvalue_datum(bcx, "trans_imm_cast", expr.id)); let llexpr_ptr = datum.to_llref(); let lldiscrim_a = adt::trans_get_discr(bcx, repr, llexpr_ptr, Some(Type::i64())); match k_out { cast_integral => int_cast(bcx, ll_t_out, val_ty(lldiscrim_a), lldiscrim_a, true), cast_float => SIToFP(bcx, lldiscrim_a, ll_t_out), _ => ccx.sess.bug(format!("translating unsupported cast: \ {} ({:?}) -> {} ({:?})", t_in.repr(ccx.tcx), k_in, t_out.repr(ccx.tcx), k_out)) } } _ => ccx.sess.bug(format!("translating unsupported cast: \ {} ({:?}) -> {} ({:?})", t_in.repr(ccx.tcx), k_in, t_out.repr(ccx.tcx), k_out)) }; return immediate_rvalue_bcx(bcx, newval, t_out).to_expr_datumblock(); } fn trans_assign_op<'a>( bcx: &'a Block<'a>, expr: &ast::Expr, _callee_id: ast::NodeId, op: ast::BinOp, dst: &ast::Expr, src: @ast::Expr) -> &'a Block<'a> { let _icx = push_ctxt("trans_assign_op"); let mut bcx = bcx; debug!("trans_assign_op(expr={})", bcx.expr_to_str(expr)); // User-defined operator methods cannot be used with `+=` etc right now assert!({ let method_map = bcx.ccx().maps.method_map.borrow(); !method_map.get().find(&expr.id).is_some() }); // Evaluate LHS (destination), which should be an lvalue let dst_datum = unpack_datum!(bcx, trans_to_lvalue(bcx, dst, "assign_op")); assert!(!ty::type_needs_drop(bcx.tcx(), dst_datum.ty)); let dst_ty = dst_datum.ty; let dst = Load(bcx, dst_datum.val); // Evaluate RHS let rhs_datum = unpack_datum!(bcx, trans(bcx, src)); let rhs_ty = rhs_datum.ty; let rhs = rhs_datum.to_llscalarish(bcx); // Perform computation and store the result let result_datum = unpack_datum!( bcx, trans_eager_binop(bcx, expr, dst_datum.ty, op, dst_ty, dst, rhs_ty, rhs)); return result_datum.store_to(bcx, dst_datum.val); } fn trans_log_level<'a>(bcx: &'a Block<'a>) -> DatumBlock<'a, Expr> { let _icx = push_ctxt("trans_log_level"); let ccx = bcx.ccx(); let (modpath, modname) = { let srccrate; { let external_srcs = ccx.external_srcs.borrow(); srccrate = match external_srcs.get().find(&bcx.fcx.id) { Some(&src) => { ccx.sess.cstore.get_crate_data(src.crate).name } None => ccx.link_meta.crateid.name.to_managed(), }; }; let mut modpath = ~[PathMod(ccx.sess.ident_of(srccrate))]; for e in bcx.fcx.path.iter() { match *e { PathMod(_) => { modpath.push(*e) } _ => {} } } let modname = path_str(ccx.sess, modpath); (modpath, modname) }; let module_data_exists; { let module_data = ccx.module_data.borrow(); module_data_exists = module_data.get().contains_key(&modname); } let global = if module_data_exists { let mut module_data = ccx.module_data.borrow_mut(); module_data.get().get_copy(&modname) } else { let s = link::mangle_internal_name_by_path_and_seq( ccx, modpath, "loglevel"); let global; unsafe { global = s.with_c_str(|buf| { llvm::LLVMAddGlobal(ccx.llmod, Type::i32().to_ref(), buf) }); llvm::LLVMSetGlobalConstant(global, False); llvm::LLVMSetInitializer(global, C_null(Type::i32())); lib::llvm::SetLinkage(global, lib::llvm::InternalLinkage); } { let mut module_data = ccx.module_data.borrow_mut(); module_data.get().insert(modname, global); global } }; immediate_rvalue_bcx(bcx, Load(bcx, global), ty::mk_u32()).to_expr_datumblock() } fn deref_multiple<'a>(bcx: &'a Block<'a>, expr: &ast::Expr, datum: Datum, times: uint) -> DatumBlock<'a, Expr> { let mut bcx = bcx; let mut datum = datum; for i in range(1, times+1) { datum = unpack_datum!(bcx, deref_once(bcx, expr, datum, i)); } DatumBlock { bcx: bcx, datum: datum } } fn deref_once<'a>(bcx: &'a Block<'a>, expr: &ast::Expr, datum: Datum, derefs: uint) -> DatumBlock<'a, Expr> { let ccx = bcx.ccx(); let bcx = write_guard::root_and_write_guard(&datum, bcx, expr.span, expr.id, derefs); debug!("deref_once(expr={}, datum={}, derefs={})", expr.repr(bcx.tcx()), datum.to_str(ccx), derefs); let mut bcx = bcx; let r = match ty::get(datum.ty).sty { ty::ty_uniq(content_ty) => { deref_owned_pointer(bcx, expr, datum, content_ty) } ty::ty_box(content_ty) => { let datum = unpack_datum!( bcx, datum.to_lvalue_datum(bcx, "deref", expr.id)); let llptrref = datum.to_llref(); let llptr = Load(bcx, llptrref); let llbody = GEPi(bcx, llptr, [0u, abi::box_field_body]); DatumBlock(bcx, Datum(llbody, content_ty, LvalueExpr)) } ty::ty_ptr(ty::mt { ty: content_ty, .. }) | ty::ty_rptr(_, ty::mt { ty: content_ty, .. }) => { assert!(!ty::type_needs_drop(bcx.tcx(), datum.ty)); let ptr = datum.to_llscalarish(bcx); // Always generate an lvalue datum, even if datum.mode is // an rvalue. This is because datum.mode is only an // rvalue for non-owning pointers like &T or *T, in which // case cleanup *is* scheduled elsewhere, by the true // owner (or, in the case of *T, by the user). DatumBlock(bcx, Datum(ptr, content_ty, LvalueExpr)) } ty::ty_enum(..) | ty::ty_struct(..) => { // Subtle efficiency note: In the case where we have a // newtype struct where the struct itself does not have a // dtor, but the contents do, we could avoid forcing the // data into Lvalue and instead return an Rvalue. But it // doesn't seem worth the trouble. let datum = unpack_datum!(bcx, ensure_cleanup(bcx, expr, datum)); // Unlike the pointer case above, we generate an // rvalue datum if we are given an rvalue. There are // two reasons that this makes sense here: // // 1. dereferencing a struct does not actually perform a // pointer load and hence the resulting value is not // naturally by reference, as would be required by an // lvalue result. // // 2. the struct always owns its contents, and hence and does not // itself have a dtor (else it would be in lvalue mode). let repr = adt::represent_type(ccx, datum.ty); let ty = adt::deref_ty(ccx, repr); let Datum { val, kind, .. } = datum; let r = match kind { LvalueExpr => { Datum { val: adt::trans_field_ptr(bcx, repr, val, 0, 0), ty: ty, kind: LvalueExpr } } RvalueExpr(Rvalue { mode: ByRef }) => { Datum { val: adt::trans_field_ptr(bcx, repr, val, 0, 0), ty: ty, kind: RvalueExpr(Rvalue(ByValue)) } } RvalueExpr(Rvalue { mode: ByValue }) => { Datum { val: ExtractValue(bcx, val, 0), ty: ty, kind: RvalueExpr(Rvalue(ByValue)) } } }; DatumBlock(bcx, r) } _ => { bcx.tcx().sess.span_bug( expr.span, format!("deref invoked on expr of illegal type {}", datum.ty.repr(bcx.tcx()))); } }; debug!("deref_once(expr={}, derefs={}, result={})", expr.id, derefs, r.datum.to_str(ccx)); return r; fn ensure_cleanup<'a>(mut bcx: &'a Block<'a>, expr: &ast::Expr, datum: Datum) -> DatumBlock<'a, Expr> { /*! * If the datum contains data that needs to be dropped, * convert it to an lvalue, thus ensuring that cleanup * is scheduled. */ if ty::type_needs_drop(bcx.tcx(), datum.ty) { let lv_datum = unpack_datum!( bcx, datum.to_lvalue_datum(bcx, "deref", expr.id)); DatumBlock(bcx, lv_datum.to_expr_datum()) } else { DatumBlock(bcx, datum) } } fn deref_owned_pointer<'a>(bcx: &'a Block<'a>, expr: &ast::Expr, datum: Datum, content_ty: ty::t) -> DatumBlock<'a, Expr> { /*! * We microoptimize derefs of owned pointers a bit here. * Basically, the idea is to make the deref of an rvalue * result in an rvalue. This helps to avoid intermediate stack * slots in the resulting LLVM. The idea here is that, if the * `~T` pointer is an rvalue, then we can schedule a *shallow* * free of the `~T` pointer, and then return a ByRef rvalue * into the pointer. Because the free is shallow, it is legit * to return an rvalue, because we know that the contents are * not yet scheduled to be freed. The language rules ensure that the * contents will be used (or moved) before the free occurs. */ match datum.kind { RvalueExpr(Rvalue { mode: ByRef }) => { let scope = cleanup::temporary_scope(bcx.tcx(), expr.id); let ptr = Load(bcx, datum.val); bcx.fcx.schedule_free_value(scope, ptr, heap_exchange); } RvalueExpr(Rvalue { mode: ByValue }) => { let scope = cleanup::temporary_scope(bcx.tcx(), expr.id); bcx.fcx.schedule_free_value(scope, datum.val, heap_exchange); } LvalueExpr => { } } // If we had an rvalue in, we produce an rvalue out. let (llptr, kind) = match datum.kind { LvalueExpr => { (Load(bcx, datum.val), LvalueExpr) } RvalueExpr(Rvalue { mode: ByRef }) => { (Load(bcx, datum.val), RvalueExpr(Rvalue(ByRef))) } RvalueExpr(Rvalue { mode: ByValue }) => { (datum.val, RvalueExpr(Rvalue(ByRef))) } }; let datum = Datum { ty: content_ty, val: llptr, kind: kind }; DatumBlock { bcx: bcx, datum: datum } } }