| // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| use llvm::{self, ValueRef, BasicBlockRef}; |
| use rustc::middle::lang_items; |
| use rustc::middle::const_val::{ConstEvalErr, ConstInt, ErrKind}; |
| use rustc::ty::{self, TypeFoldable}; |
| use rustc::ty::layout::{self, LayoutOf}; |
| use rustc::traits; |
| use rustc::mir; |
| use abi::{Abi, FnType, ArgType, PassMode}; |
| use base; |
| use callee; |
| use builder::Builder; |
| use common::{self, C_bool, C_str_slice, C_struct, C_u32, C_undef}; |
| use consts; |
| use meth; |
| use monomorphize; |
| use type_of::LayoutLlvmExt; |
| use type_::Type; |
| |
| use syntax::symbol::Symbol; |
| use syntax_pos::Pos; |
| |
| use super::{FunctionCx, LocalRef}; |
| use super::constant::Const; |
| use super::place::PlaceRef; |
| use super::operand::OperandRef; |
| use super::operand::OperandValue::{Pair, Ref, Immediate}; |
| |
| impl<'a, 'tcx> FunctionCx<'a, 'tcx> { |
| pub fn trans_block(&mut self, bb: mir::BasicBlock) { |
| let mut bx = self.build_block(bb); |
| let data = &self.mir[bb]; |
| |
| debug!("trans_block({:?}={:?})", bb, data); |
| |
| for statement in &data.statements { |
| bx = self.trans_statement(bx, statement); |
| } |
| |
| self.trans_terminator(bx, bb, data.terminator()); |
| } |
| |
| fn trans_terminator(&mut self, |
| mut bx: Builder<'a, 'tcx>, |
| bb: mir::BasicBlock, |
| terminator: &mir::Terminator<'tcx>) |
| { |
| debug!("trans_terminator: {:?}", terminator); |
| |
| // Create the cleanup bundle, if needed. |
| let tcx = bx.tcx(); |
| let span = terminator.source_info.span; |
| let funclet_bb = self.cleanup_kinds[bb].funclet_bb(bb); |
| let funclet = funclet_bb.and_then(|funclet_bb| self.funclets[funclet_bb].as_ref()); |
| |
| let cleanup_pad = funclet.map(|lp| lp.cleanuppad()); |
| let cleanup_bundle = funclet.map(|l| l.bundle()); |
| |
| let lltarget = |this: &mut Self, target: mir::BasicBlock| { |
| let lltarget = this.blocks[target]; |
| let target_funclet = this.cleanup_kinds[target].funclet_bb(target); |
| match (funclet_bb, target_funclet) { |
| (None, None) => (lltarget, false), |
| (Some(f), Some(t_f)) |
| if f == t_f || !base::wants_msvc_seh(tcx.sess) |
| => (lltarget, false), |
| (None, Some(_)) => { |
| // jump *into* cleanup - need a landing pad if GNU |
| (this.landing_pad_to(target), false) |
| } |
| (Some(_), None) => span_bug!(span, "{:?} - jump out of cleanup?", terminator), |
| (Some(_), Some(_)) => { |
| (this.landing_pad_to(target), true) |
| } |
| } |
| }; |
| |
| let llblock = |this: &mut Self, target: mir::BasicBlock| { |
| let (lltarget, is_cleanupret) = lltarget(this, target); |
| if is_cleanupret { |
| // MSVC cross-funclet jump - need a trampoline |
| |
| debug!("llblock: creating cleanup trampoline for {:?}", target); |
| let name = &format!("{:?}_cleanup_trampoline_{:?}", bb, target); |
| let trampoline = this.new_block(name); |
| trampoline.cleanup_ret(cleanup_pad.unwrap(), Some(lltarget)); |
| trampoline.llbb() |
| } else { |
| lltarget |
| } |
| }; |
| |
| let funclet_br = |this: &mut Self, bx: Builder, target: mir::BasicBlock| { |
| let (lltarget, is_cleanupret) = lltarget(this, target); |
| if is_cleanupret { |
| // micro-optimization: generate a `ret` rather than a jump |
| // to a trampoline. |
| bx.cleanup_ret(cleanup_pad.unwrap(), Some(lltarget)); |
| } else { |
| bx.br(lltarget); |
| } |
| }; |
| |
| let do_call = | |
| this: &mut Self, |
| bx: Builder<'a, 'tcx>, |
| fn_ty: FnType<'tcx>, |
| fn_ptr: ValueRef, |
| llargs: &[ValueRef], |
| destination: Option<(ReturnDest<'tcx>, mir::BasicBlock)>, |
| cleanup: Option<mir::BasicBlock> |
| | { |
| if let Some(cleanup) = cleanup { |
| let ret_bx = if let Some((_, target)) = destination { |
| this.blocks[target] |
| } else { |
| this.unreachable_block() |
| }; |
| let invokeret = bx.invoke(fn_ptr, |
| &llargs, |
| ret_bx, |
| llblock(this, cleanup), |
| cleanup_bundle); |
| fn_ty.apply_attrs_callsite(invokeret); |
| |
| if let Some((ret_dest, target)) = destination { |
| let ret_bx = this.build_block(target); |
| this.set_debug_loc(&ret_bx, terminator.source_info); |
| this.store_return(&ret_bx, ret_dest, &fn_ty.ret, invokeret); |
| } |
| } else { |
| let llret = bx.call(fn_ptr, &llargs, cleanup_bundle); |
| fn_ty.apply_attrs_callsite(llret); |
| if this.mir[bb].is_cleanup { |
| // Cleanup is always the cold path. Don't inline |
| // drop glue. Also, when there is a deeply-nested |
| // struct, there are "symmetry" issues that cause |
| // exponential inlining - see issue #41696. |
| llvm::Attribute::NoInline.apply_callsite(llvm::AttributePlace::Function, llret); |
| } |
| |
| if let Some((ret_dest, target)) = destination { |
| this.store_return(&bx, ret_dest, &fn_ty.ret, llret); |
| funclet_br(this, bx, target); |
| } else { |
| bx.unreachable(); |
| } |
| } |
| }; |
| |
| self.set_debug_loc(&bx, terminator.source_info); |
| match terminator.kind { |
| mir::TerminatorKind::Resume => { |
| if let Some(cleanup_pad) = cleanup_pad { |
| bx.cleanup_ret(cleanup_pad, None); |
| } else { |
| let slot = self.get_personality_slot(&bx); |
| let lp0 = slot.project_field(&bx, 0).load(&bx).immediate(); |
| let lp1 = slot.project_field(&bx, 1).load(&bx).immediate(); |
| slot.storage_dead(&bx); |
| |
| if !bx.sess().target.target.options.custom_unwind_resume { |
| let mut lp = C_undef(self.landing_pad_type()); |
| lp = bx.insert_value(lp, lp0, 0); |
| lp = bx.insert_value(lp, lp1, 1); |
| bx.resume(lp); |
| } else { |
| bx.call(bx.cx.eh_unwind_resume(), &[lp0], cleanup_bundle); |
| bx.unreachable(); |
| } |
| } |
| } |
| |
| mir::TerminatorKind::Abort => { |
| // Call core::intrinsics::abort() |
| let fnname = bx.cx.get_intrinsic(&("llvm.trap")); |
| bx.call(fnname, &[], None); |
| bx.unreachable(); |
| } |
| |
| mir::TerminatorKind::Goto { target } => { |
| funclet_br(self, bx, target); |
| } |
| |
| mir::TerminatorKind::SwitchInt { ref discr, switch_ty, ref values, ref targets } => { |
| let discr = self.trans_operand(&bx, discr); |
| if switch_ty == bx.tcx().types.bool { |
| let lltrue = llblock(self, targets[0]); |
| let llfalse = llblock(self, targets[1]); |
| if let [ConstInt::U8(0)] = values[..] { |
| bx.cond_br(discr.immediate(), llfalse, lltrue); |
| } else { |
| bx.cond_br(discr.immediate(), lltrue, llfalse); |
| } |
| } else { |
| let (otherwise, targets) = targets.split_last().unwrap(); |
| let switch = bx.switch(discr.immediate(), |
| llblock(self, *otherwise), values.len()); |
| for (value, target) in values.iter().zip(targets) { |
| let val = Const::from_constint(bx.cx, value); |
| let llbb = llblock(self, *target); |
| bx.add_case(switch, val.llval, llbb) |
| } |
| } |
| } |
| |
| mir::TerminatorKind::Return => { |
| let llval = match self.fn_ty.ret.mode { |
| PassMode::Ignore | PassMode::Indirect(_) => { |
| bx.ret_void(); |
| return; |
| } |
| |
| PassMode::Direct(_) | PassMode::Pair(..) => { |
| let op = self.trans_consume(&bx, &mir::Place::Local(mir::RETURN_PLACE)); |
| if let Ref(llval, align) = op.val { |
| bx.load(llval, align) |
| } else { |
| op.immediate_or_packed_pair(&bx) |
| } |
| } |
| |
| PassMode::Cast(cast_ty) => { |
| let op = match self.locals[mir::RETURN_PLACE] { |
| LocalRef::Operand(Some(op)) => op, |
| LocalRef::Operand(None) => bug!("use of return before def"), |
| LocalRef::Place(tr_place) => { |
| OperandRef { |
| val: Ref(tr_place.llval, tr_place.align), |
| layout: tr_place.layout |
| } |
| } |
| }; |
| let llslot = match op.val { |
| Immediate(_) | Pair(..) => { |
| let scratch = PlaceRef::alloca(&bx, self.fn_ty.ret.layout, "ret"); |
| op.val.store(&bx, scratch); |
| scratch.llval |
| } |
| Ref(llval, align) => { |
| assert_eq!(align.abi(), op.layout.align.abi(), |
| "return place is unaligned!"); |
| llval |
| } |
| }; |
| bx.load( |
| bx.pointercast(llslot, cast_ty.llvm_type(bx.cx).ptr_to()), |
| self.fn_ty.ret.layout.align) |
| } |
| }; |
| bx.ret(llval); |
| } |
| |
| mir::TerminatorKind::Unreachable => { |
| bx.unreachable(); |
| } |
| |
| mir::TerminatorKind::Drop { ref location, target, unwind } => { |
| let ty = location.ty(self.mir, bx.tcx()).to_ty(bx.tcx()); |
| let ty = self.monomorphize(&ty); |
| let drop_fn = monomorphize::resolve_drop_in_place(bx.cx.tcx, ty); |
| |
| if let ty::InstanceDef::DropGlue(_, None) = drop_fn.def { |
| // we don't actually need to drop anything. |
| funclet_br(self, bx, target); |
| return |
| } |
| |
| let place = self.trans_place(&bx, location); |
| let mut args: &[_] = &[place.llval, place.llextra]; |
| args = &args[..1 + place.has_extra() as usize]; |
| let (drop_fn, fn_ty) = match ty.sty { |
| ty::TyDynamic(..) => { |
| let fn_ty = drop_fn.ty(bx.cx.tcx); |
| let sig = common::ty_fn_sig(bx.cx, fn_ty); |
| let sig = bx.tcx().erase_late_bound_regions_and_normalize(&sig); |
| let fn_ty = FnType::new_vtable(bx.cx, sig, &[]); |
| args = &args[..1]; |
| (meth::DESTRUCTOR.get_fn(&bx, place.llextra, &fn_ty), fn_ty) |
| } |
| _ => { |
| (callee::get_fn(bx.cx, drop_fn), |
| FnType::of_instance(bx.cx, &drop_fn)) |
| } |
| }; |
| do_call(self, bx, fn_ty, drop_fn, args, |
| Some((ReturnDest::Nothing, target)), |
| unwind); |
| } |
| |
| mir::TerminatorKind::Assert { ref cond, expected, ref msg, target, cleanup } => { |
| let cond = self.trans_operand(&bx, cond).immediate(); |
| let mut const_cond = common::const_to_opt_u128(cond, false).map(|c| c == 1); |
| |
| // This case can currently arise only from functions marked |
| // with #[rustc_inherit_overflow_checks] and inlined from |
| // another crate (mostly core::num generic/#[inline] fns), |
| // while the current crate doesn't use overflow checks. |
| // NOTE: Unlike binops, negation doesn't have its own |
| // checked operation, just a comparison with the minimum |
| // value, so we have to check for the assert message. |
| if !bx.cx.check_overflow { |
| use rustc_const_math::ConstMathErr::Overflow; |
| use rustc_const_math::Op::Neg; |
| |
| if let mir::AssertMessage::Math(Overflow(Neg)) = *msg { |
| const_cond = Some(expected); |
| } |
| } |
| |
| // Don't translate the panic block if success if known. |
| if const_cond == Some(expected) { |
| funclet_br(self, bx, target); |
| return; |
| } |
| |
| // Pass the condition through llvm.expect for branch hinting. |
| let expect = bx.cx.get_intrinsic(&"llvm.expect.i1"); |
| let cond = bx.call(expect, &[cond, C_bool(bx.cx, expected)], None); |
| |
| // Create the failure block and the conditional branch to it. |
| let lltarget = llblock(self, target); |
| let panic_block = self.new_block("panic"); |
| if expected { |
| bx.cond_br(cond, lltarget, panic_block.llbb()); |
| } else { |
| bx.cond_br(cond, panic_block.llbb(), lltarget); |
| } |
| |
| // After this point, bx is the block for the call to panic. |
| bx = panic_block; |
| self.set_debug_loc(&bx, terminator.source_info); |
| |
| // Get the location information. |
| let loc = bx.sess().codemap().lookup_char_pos(span.lo()); |
| let filename = Symbol::intern(&loc.file.name.to_string()).as_str(); |
| let filename = C_str_slice(bx.cx, filename); |
| let line = C_u32(bx.cx, loc.line as u32); |
| let col = C_u32(bx.cx, loc.col.to_usize() as u32 + 1); |
| let align = tcx.data_layout.aggregate_align |
| .max(tcx.data_layout.i32_align) |
| .max(tcx.data_layout.pointer_align); |
| |
| // Put together the arguments to the panic entry point. |
| let (lang_item, args, const_err) = match *msg { |
| mir::AssertMessage::BoundsCheck { ref len, ref index } => { |
| let len = self.trans_operand(&mut bx, len).immediate(); |
| let index = self.trans_operand(&mut bx, index).immediate(); |
| |
| let const_err = common::const_to_opt_u128(len, false) |
| .and_then(|len| common::const_to_opt_u128(index, false) |
| .map(|index| ErrKind::IndexOutOfBounds { |
| len: len as u64, |
| index: index as u64 |
| })); |
| |
| let file_line_col = C_struct(bx.cx, &[filename, line, col], false); |
| let file_line_col = consts::addr_of(bx.cx, |
| file_line_col, |
| align, |
| "panic_bounds_check_loc"); |
| (lang_items::PanicBoundsCheckFnLangItem, |
| vec![file_line_col, index, len], |
| const_err) |
| } |
| mir::AssertMessage::Math(ref err) => { |
| let msg_str = Symbol::intern(err.description()).as_str(); |
| let msg_str = C_str_slice(bx.cx, msg_str); |
| let msg_file_line_col = C_struct(bx.cx, |
| &[msg_str, filename, line, col], |
| false); |
| let msg_file_line_col = consts::addr_of(bx.cx, |
| msg_file_line_col, |
| align, |
| "panic_loc"); |
| (lang_items::PanicFnLangItem, |
| vec![msg_file_line_col], |
| Some(ErrKind::Math(err.clone()))) |
| } |
| mir::AssertMessage::GeneratorResumedAfterReturn | |
| mir::AssertMessage::GeneratorResumedAfterPanic => { |
| let str = if let mir::AssertMessage::GeneratorResumedAfterReturn = *msg { |
| "generator resumed after completion" |
| } else { |
| "generator resumed after panicking" |
| }; |
| let msg_str = Symbol::intern(str).as_str(); |
| let msg_str = C_str_slice(bx.cx, msg_str); |
| let msg_file_line_col = C_struct(bx.cx, |
| &[msg_str, filename, line, col], |
| false); |
| let msg_file_line_col = consts::addr_of(bx.cx, |
| msg_file_line_col, |
| align, |
| "panic_loc"); |
| (lang_items::PanicFnLangItem, |
| vec![msg_file_line_col], |
| None) |
| } |
| }; |
| |
| // If we know we always panic, and the error message |
| // is also constant, then we can produce a warning. |
| if const_cond == Some(!expected) { |
| if let Some(err) = const_err { |
| let err = ConstEvalErr{ span: span, kind: err }; |
| let mut diag = bx.tcx().sess.struct_span_warn( |
| span, "this expression will panic at run-time"); |
| err.note(bx.tcx(), span, "expression", &mut diag); |
| diag.emit(); |
| } |
| } |
| |
| // Obtain the panic entry point. |
| let def_id = common::langcall(bx.tcx(), Some(span), "", lang_item); |
| let instance = ty::Instance::mono(bx.tcx(), def_id); |
| let fn_ty = FnType::of_instance(bx.cx, &instance); |
| let llfn = callee::get_fn(bx.cx, instance); |
| |
| // Translate the actual panic invoke/call. |
| do_call(self, bx, fn_ty, llfn, &args, None, cleanup); |
| } |
| |
| mir::TerminatorKind::DropAndReplace { .. } => { |
| bug!("undesugared DropAndReplace in trans: {:?}", terminator); |
| } |
| |
| mir::TerminatorKind::Call { ref func, ref args, ref destination, cleanup } => { |
| // Create the callee. This is a fn ptr or zero-sized and hence a kind of scalar. |
| let callee = self.trans_operand(&bx, func); |
| |
| let (instance, mut llfn) = match callee.layout.ty.sty { |
| ty::TyFnDef(def_id, substs) => { |
| (Some(ty::Instance::resolve(bx.cx.tcx, |
| ty::ParamEnv::empty(traits::Reveal::All), |
| def_id, |
| substs).unwrap()), |
| None) |
| } |
| ty::TyFnPtr(_) => { |
| (None, Some(callee.immediate())) |
| } |
| _ => bug!("{} is not callable", callee.layout.ty) |
| }; |
| let def = instance.map(|i| i.def); |
| let sig = callee.layout.ty.fn_sig(bx.tcx()); |
| let sig = bx.tcx().erase_late_bound_regions_and_normalize(&sig); |
| let abi = sig.abi; |
| |
| // Handle intrinsics old trans wants Expr's for, ourselves. |
| let intrinsic = match def { |
| Some(ty::InstanceDef::Intrinsic(def_id)) |
| => Some(bx.tcx().item_name(def_id)), |
| _ => None |
| }; |
| let intrinsic = intrinsic.as_ref().map(|s| &s[..]); |
| |
| if intrinsic == Some("transmute") { |
| let &(ref dest, target) = destination.as_ref().unwrap(); |
| self.trans_transmute(&bx, &args[0], dest); |
| funclet_br(self, bx, target); |
| return; |
| } |
| |
| let extra_args = &args[sig.inputs().len()..]; |
| let extra_args = extra_args.iter().map(|op_arg| { |
| let op_ty = op_arg.ty(self.mir, bx.tcx()); |
| self.monomorphize(&op_ty) |
| }).collect::<Vec<_>>(); |
| |
| let fn_ty = match def { |
| Some(ty::InstanceDef::Virtual(..)) => { |
| FnType::new_vtable(bx.cx, sig, &extra_args) |
| } |
| Some(ty::InstanceDef::DropGlue(_, None)) => { |
| // empty drop glue - a nop. |
| let &(_, target) = destination.as_ref().unwrap(); |
| funclet_br(self, bx, target); |
| return; |
| } |
| _ => FnType::new(bx.cx, sig, &extra_args) |
| }; |
| |
| // The arguments we'll be passing. Plus one to account for outptr, if used. |
| let arg_count = fn_ty.args.len() + fn_ty.ret.is_indirect() as usize; |
| let mut llargs = Vec::with_capacity(arg_count); |
| |
| // Prepare the return value destination |
| let ret_dest = if let Some((ref dest, _)) = *destination { |
| let is_intrinsic = intrinsic.is_some(); |
| self.make_return_dest(&bx, dest, &fn_ty.ret, &mut llargs, |
| is_intrinsic) |
| } else { |
| ReturnDest::Nothing |
| }; |
| |
| if intrinsic.is_some() && intrinsic != Some("drop_in_place") { |
| use intrinsic::trans_intrinsic_call; |
| |
| let dest = match ret_dest { |
| _ if fn_ty.ret.is_indirect() => llargs[0], |
| ReturnDest::Nothing => { |
| C_undef(fn_ty.ret.memory_ty(bx.cx).ptr_to()) |
| } |
| ReturnDest::IndirectOperand(dst, _) | |
| ReturnDest::Store(dst) => dst.llval, |
| ReturnDest::DirectOperand(_) => |
| bug!("Cannot use direct operand with an intrinsic call") |
| }; |
| |
| let args: Vec<_> = args.iter().enumerate().map(|(i, arg)| { |
| // The indices passed to simd_shuffle* in the |
| // third argument must be constant. This is |
| // checked by const-qualification, which also |
| // promotes any complex rvalues to constants. |
| if i == 2 && intrinsic.unwrap().starts_with("simd_shuffle") { |
| match *arg { |
| mir::Operand::Copy(_) | |
| mir::Operand::Move(_) => { |
| span_bug!(span, "shuffle indices must be constant"); |
| } |
| mir::Operand::Constant(ref constant) => { |
| let val = self.trans_constant(&bx, constant); |
| return OperandRef { |
| val: Immediate(val.llval), |
| layout: bx.cx.layout_of(val.ty) |
| }; |
| } |
| } |
| } |
| |
| self.trans_operand(&bx, arg) |
| }).collect(); |
| |
| |
| let callee_ty = instance.as_ref().unwrap().ty(bx.cx.tcx); |
| trans_intrinsic_call(&bx, callee_ty, &fn_ty, &args, dest, |
| terminator.source_info.span); |
| |
| if let ReturnDest::IndirectOperand(dst, _) = ret_dest { |
| self.store_return(&bx, ret_dest, &fn_ty.ret, dst.llval); |
| } |
| |
| if let Some((_, target)) = *destination { |
| funclet_br(self, bx, target); |
| } else { |
| bx.unreachable(); |
| } |
| |
| return; |
| } |
| |
| // Split the rust-call tupled arguments off. |
| let (first_args, untuple) = if abi == Abi::RustCall && !args.is_empty() { |
| let (tup, args) = args.split_last().unwrap(); |
| (args, Some(tup)) |
| } else { |
| (&args[..], None) |
| }; |
| |
| for (i, arg) in first_args.iter().enumerate() { |
| let mut op = self.trans_operand(&bx, arg); |
| if let (0, Some(ty::InstanceDef::Virtual(_, idx))) = (i, def) { |
| if let Pair(data_ptr, meta) = op.val { |
| llfn = Some(meth::VirtualIndex::from_index(idx) |
| .get_fn(&bx, meta, &fn_ty)); |
| llargs.push(data_ptr); |
| continue; |
| } |
| } |
| |
| // The callee needs to own the argument memory if we pass it |
| // by-ref, so make a local copy of non-immediate constants. |
| match (arg, op.val) { |
| (&mir::Operand::Copy(_), Ref(..)) | |
| (&mir::Operand::Constant(_), Ref(..)) => { |
| let tmp = PlaceRef::alloca(&bx, op.layout, "const"); |
| op.val.store(&bx, tmp); |
| op.val = Ref(tmp.llval, tmp.align); |
| } |
| _ => {} |
| } |
| |
| self.trans_argument(&bx, op, &mut llargs, &fn_ty.args[i]); |
| } |
| if let Some(tup) = untuple { |
| self.trans_arguments_untupled(&bx, tup, &mut llargs, |
| &fn_ty.args[first_args.len()..]) |
| } |
| |
| let fn_ptr = match (llfn, instance) { |
| (Some(llfn), _) => llfn, |
| (None, Some(instance)) => callee::get_fn(bx.cx, instance), |
| _ => span_bug!(span, "no llfn for call"), |
| }; |
| |
| do_call(self, bx, fn_ty, fn_ptr, &llargs, |
| destination.as_ref().map(|&(_, target)| (ret_dest, target)), |
| cleanup); |
| } |
| mir::TerminatorKind::GeneratorDrop | |
| mir::TerminatorKind::Yield { .. } | |
| mir::TerminatorKind::FalseEdges { .. } => bug!("generator ops in trans"), |
| } |
| } |
| |
| fn trans_argument(&mut self, |
| bx: &Builder<'a, 'tcx>, |
| op: OperandRef<'tcx>, |
| llargs: &mut Vec<ValueRef>, |
| arg: &ArgType<'tcx>) { |
| // Fill padding with undef value, where applicable. |
| if let Some(ty) = arg.pad { |
| llargs.push(C_undef(ty.llvm_type(bx.cx))); |
| } |
| |
| if arg.is_ignore() { |
| return; |
| } |
| |
| if let PassMode::Pair(..) = arg.mode { |
| match op.val { |
| Pair(a, b) => { |
| llargs.push(a); |
| llargs.push(b); |
| return; |
| } |
| _ => bug!("trans_argument: {:?} invalid for pair arugment", op) |
| } |
| } |
| |
| // Force by-ref if we have to load through a cast pointer. |
| let (mut llval, align, by_ref) = match op.val { |
| Immediate(_) | Pair(..) => { |
| match arg.mode { |
| PassMode::Indirect(_) | PassMode::Cast(_) => { |
| let scratch = PlaceRef::alloca(bx, arg.layout, "arg"); |
| op.val.store(bx, scratch); |
| (scratch.llval, scratch.align, true) |
| } |
| _ => { |
| (op.immediate_or_packed_pair(bx), arg.layout.align, false) |
| } |
| } |
| } |
| Ref(llval, align) => { |
| if arg.is_indirect() && align.abi() < arg.layout.align.abi() { |
| // `foo(packed.large_field)`. We can't pass the (unaligned) field directly. I |
| // think that ATM (Rust 1.16) we only pass temporaries, but we shouldn't |
| // have scary latent bugs around. |
| |
| let scratch = PlaceRef::alloca(bx, arg.layout, "arg"); |
| base::memcpy_ty(bx, scratch.llval, llval, op.layout, align); |
| (scratch.llval, scratch.align, true) |
| } else { |
| (llval, align, true) |
| } |
| } |
| }; |
| |
| if by_ref && !arg.is_indirect() { |
| // Have to load the argument, maybe while casting it. |
| if let PassMode::Cast(ty) = arg.mode { |
| llval = bx.load(bx.pointercast(llval, ty.llvm_type(bx.cx).ptr_to()), |
| align.min(arg.layout.align)); |
| } else { |
| // We can't use `PlaceRef::load` here because the argument |
| // may have a type we don't treat as immediate, but the ABI |
| // used for this call is passing it by-value. In that case, |
| // the load would just produce `OperandValue::Ref` instead |
| // of the `OperandValue::Immediate` we need for the call. |
| llval = bx.load(llval, align); |
| if let layout::Abi::Scalar(ref scalar) = arg.layout.abi { |
| if scalar.is_bool() { |
| bx.range_metadata(llval, 0..2); |
| } |
| } |
| // We store bools as i8 so we need to truncate to i1. |
| llval = base::to_immediate(bx, llval, arg.layout); |
| } |
| } |
| |
| llargs.push(llval); |
| } |
| |
| fn trans_arguments_untupled(&mut self, |
| bx: &Builder<'a, 'tcx>, |
| operand: &mir::Operand<'tcx>, |
| llargs: &mut Vec<ValueRef>, |
| args: &[ArgType<'tcx>]) { |
| let tuple = self.trans_operand(bx, operand); |
| |
| // Handle both by-ref and immediate tuples. |
| if let Ref(llval, align) = tuple.val { |
| let tuple_ptr = PlaceRef::new_sized(llval, tuple.layout, align); |
| for i in 0..tuple.layout.fields.count() { |
| let field_ptr = tuple_ptr.project_field(bx, i); |
| self.trans_argument(bx, field_ptr.load(bx), llargs, &args[i]); |
| } |
| } else { |
| // If the tuple is immediate, the elements are as well. |
| for i in 0..tuple.layout.fields.count() { |
| let op = tuple.extract_field(bx, i); |
| self.trans_argument(bx, op, llargs, &args[i]); |
| } |
| } |
| } |
| |
| fn get_personality_slot(&mut self, bx: &Builder<'a, 'tcx>) -> PlaceRef<'tcx> { |
| let cx = bx.cx; |
| if let Some(slot) = self.personality_slot { |
| slot |
| } else { |
| let layout = cx.layout_of(cx.tcx.intern_tup(&[ |
| cx.tcx.mk_mut_ptr(cx.tcx.types.u8), |
| cx.tcx.types.i32 |
| ], false)); |
| let slot = PlaceRef::alloca(bx, layout, "personalityslot"); |
| self.personality_slot = Some(slot); |
| slot |
| } |
| } |
| |
| /// Return the landingpad wrapper around the given basic block |
| /// |
| /// No-op in MSVC SEH scheme. |
| fn landing_pad_to(&mut self, target_bb: mir::BasicBlock) -> BasicBlockRef { |
| if let Some(block) = self.landing_pads[target_bb] { |
| return block; |
| } |
| |
| let block = self.blocks[target_bb]; |
| let landing_pad = self.landing_pad_uncached(block); |
| self.landing_pads[target_bb] = Some(landing_pad); |
| landing_pad |
| } |
| |
| fn landing_pad_uncached(&mut self, target_bb: BasicBlockRef) -> BasicBlockRef { |
| if base::wants_msvc_seh(self.cx.sess()) { |
| span_bug!(self.mir.span, "landing pad was not inserted?") |
| } |
| |
| let bx = self.new_block("cleanup"); |
| |
| let llpersonality = self.cx.eh_personality(); |
| let llretty = self.landing_pad_type(); |
| let lp = bx.landing_pad(llretty, llpersonality, 1); |
| bx.set_cleanup(lp); |
| |
| let slot = self.get_personality_slot(&bx); |
| slot.storage_live(&bx); |
| Pair(bx.extract_value(lp, 0), bx.extract_value(lp, 1)).store(&bx, slot); |
| |
| bx.br(target_bb); |
| bx.llbb() |
| } |
| |
| fn landing_pad_type(&self) -> Type { |
| let cx = self.cx; |
| Type::struct_(cx, &[Type::i8p(cx), Type::i32(cx)], false) |
| } |
| |
| fn unreachable_block(&mut self) -> BasicBlockRef { |
| self.unreachable_block.unwrap_or_else(|| { |
| let bl = self.new_block("unreachable"); |
| bl.unreachable(); |
| self.unreachable_block = Some(bl.llbb()); |
| bl.llbb() |
| }) |
| } |
| |
| pub fn new_block(&self, name: &str) -> Builder<'a, 'tcx> { |
| Builder::new_block(self.cx, self.llfn, name) |
| } |
| |
| pub fn build_block(&self, bb: mir::BasicBlock) -> Builder<'a, 'tcx> { |
| let bx = Builder::with_cx(self.cx); |
| bx.position_at_end(self.blocks[bb]); |
| bx |
| } |
| |
| fn make_return_dest(&mut self, bx: &Builder<'a, 'tcx>, |
| dest: &mir::Place<'tcx>, fn_ret: &ArgType<'tcx>, |
| llargs: &mut Vec<ValueRef>, is_intrinsic: bool) |
| -> ReturnDest<'tcx> { |
| // If the return is ignored, we can just return a do-nothing ReturnDest |
| if fn_ret.is_ignore() { |
| return ReturnDest::Nothing; |
| } |
| let dest = if let mir::Place::Local(index) = *dest { |
| match self.locals[index] { |
| LocalRef::Place(dest) => dest, |
| LocalRef::Operand(None) => { |
| // Handle temporary places, specifically Operand ones, as |
| // they don't have allocas |
| return if fn_ret.is_indirect() { |
| // Odd, but possible, case, we have an operand temporary, |
| // but the calling convention has an indirect return. |
| let tmp = PlaceRef::alloca(bx, fn_ret.layout, "tmp_ret"); |
| tmp.storage_live(bx); |
| llargs.push(tmp.llval); |
| ReturnDest::IndirectOperand(tmp, index) |
| } else if is_intrinsic { |
| // Currently, intrinsics always need a location to store |
| // the result. so we create a temporary alloca for the |
| // result |
| let tmp = PlaceRef::alloca(bx, fn_ret.layout, "tmp_ret"); |
| tmp.storage_live(bx); |
| ReturnDest::IndirectOperand(tmp, index) |
| } else { |
| ReturnDest::DirectOperand(index) |
| }; |
| } |
| LocalRef::Operand(Some(_)) => { |
| bug!("place local already assigned to"); |
| } |
| } |
| } else { |
| self.trans_place(bx, dest) |
| }; |
| if fn_ret.is_indirect() { |
| if dest.align.abi() < dest.layout.align.abi() { |
| // Currently, MIR code generation does not create calls |
| // that store directly to fields of packed structs (in |
| // fact, the calls it creates write only to temps), |
| // |
| // If someone changes that, please update this code path |
| // to create a temporary. |
| span_bug!(self.mir.span, "can't directly store to unaligned value"); |
| } |
| llargs.push(dest.llval); |
| ReturnDest::Nothing |
| } else { |
| ReturnDest::Store(dest) |
| } |
| } |
| |
| fn trans_transmute(&mut self, bx: &Builder<'a, 'tcx>, |
| src: &mir::Operand<'tcx>, |
| dst: &mir::Place<'tcx>) { |
| if let mir::Place::Local(index) = *dst { |
| match self.locals[index] { |
| LocalRef::Place(place) => self.trans_transmute_into(bx, src, place), |
| LocalRef::Operand(None) => { |
| let dst_layout = bx.cx.layout_of(self.monomorphized_place_ty(dst)); |
| assert!(!dst_layout.ty.has_erasable_regions()); |
| let place = PlaceRef::alloca(bx, dst_layout, "transmute_temp"); |
| place.storage_live(bx); |
| self.trans_transmute_into(bx, src, place); |
| let op = place.load(bx); |
| place.storage_dead(bx); |
| self.locals[index] = LocalRef::Operand(Some(op)); |
| } |
| LocalRef::Operand(Some(op)) => { |
| assert!(op.layout.is_zst(), |
| "assigning to initialized SSAtemp"); |
| } |
| } |
| } else { |
| let dst = self.trans_place(bx, dst); |
| self.trans_transmute_into(bx, src, dst); |
| } |
| } |
| |
| fn trans_transmute_into(&mut self, bx: &Builder<'a, 'tcx>, |
| src: &mir::Operand<'tcx>, |
| dst: PlaceRef<'tcx>) { |
| let src = self.trans_operand(bx, src); |
| let llty = src.layout.llvm_type(bx.cx); |
| let cast_ptr = bx.pointercast(dst.llval, llty.ptr_to()); |
| let align = src.layout.align.min(dst.layout.align); |
| src.val.store(bx, PlaceRef::new_sized(cast_ptr, src.layout, align)); |
| } |
| |
| |
| // Stores the return value of a function call into it's final location. |
| fn store_return(&mut self, |
| bx: &Builder<'a, 'tcx>, |
| dest: ReturnDest<'tcx>, |
| ret_ty: &ArgType<'tcx>, |
| llval: ValueRef) { |
| use self::ReturnDest::*; |
| |
| match dest { |
| Nothing => (), |
| Store(dst) => ret_ty.store(bx, llval, dst), |
| IndirectOperand(tmp, index) => { |
| let op = tmp.load(bx); |
| tmp.storage_dead(bx); |
| self.locals[index] = LocalRef::Operand(Some(op)); |
| } |
| DirectOperand(index) => { |
| // If there is a cast, we have to store and reload. |
| let op = if let PassMode::Cast(_) = ret_ty.mode { |
| let tmp = PlaceRef::alloca(bx, ret_ty.layout, "tmp_ret"); |
| tmp.storage_live(bx); |
| ret_ty.store(bx, llval, tmp); |
| let op = tmp.load(bx); |
| tmp.storage_dead(bx); |
| op |
| } else { |
| OperandRef::from_immediate_or_packed_pair(bx, llval, ret_ty.layout) |
| }; |
| self.locals[index] = LocalRef::Operand(Some(op)); |
| } |
| } |
| } |
| } |
| |
| enum ReturnDest<'tcx> { |
| // Do nothing, the return value is indirect or ignored |
| Nothing, |
| // Store the return value to the pointer |
| Store(PlaceRef<'tcx>), |
| // Stores an indirect return value to an operand local place |
| IndirectOperand(PlaceRef<'tcx>, mir::Local), |
| // Stores a direct return value to an operand local place |
| DirectOperand(mir::Local) |
| } |
