1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 use llvm::{self, BasicBlock};
12 use rustc::middle::lang_items;
13 use rustc::ty::{self, Ty, TypeFoldable};
14 use rustc::ty::layout::{self, LayoutOf};
16 use rustc::mir::interpret::EvalErrorKind;
17 use abi::{Abi, ArgType, ArgTypeExt, FnType, FnTypeExt, LlvmType, PassMode};
20 use builder::{Builder, MemFlags};
21 use common::{self, C_bool, C_str_slice, C_struct, C_u32, C_uint_big, C_undef};
25 use type_of::LayoutLlvmExt;
29 use syntax::symbol::Symbol;
32 use super::{FunctionCx, LocalRef};
33 use super::place::PlaceRef;
34 use super::operand::OperandRef;
35 use super::operand::OperandValue::{Pair, Ref, Immediate};
37 impl FunctionCx<'a, 'll, 'tcx> {
38 pub fn codegen_block(&mut self, bb: mir::BasicBlock) {
39 let mut bx = self.build_block(bb);
40 let data = &self.mir[bb];
42 debug!("codegen_block({:?}={:?})", bb, data);
44 for statement in &data.statements {
45 bx = self.codegen_statement(bx, statement);
48 self.codegen_terminator(bx, bb, data.terminator());
51 fn codegen_terminator(&mut self,
52 mut bx: Builder<'a, 'll, 'tcx>,
54 terminator: &mir::Terminator<'tcx>)
56 debug!("codegen_terminator: {:?}", terminator);
58 // Create the cleanup bundle, if needed.
60 let span = terminator.source_info.span;
61 let funclet_bb = self.cleanup_kinds[bb].funclet_bb(bb);
62 let funclet = funclet_bb.and_then(|funclet_bb| self.funclets[funclet_bb].as_ref());
64 let cleanup_pad = funclet.map(|lp| lp.cleanuppad());
65 let cleanup_bundle = funclet.map(|l| l.bundle());
67 let lltarget = |this: &mut Self, target: mir::BasicBlock| {
68 let lltarget = this.blocks[target];
69 let target_funclet = this.cleanup_kinds[target].funclet_bb(target);
70 match (funclet_bb, target_funclet) {
71 (None, None) => (lltarget, false),
73 if f == t_f || !base::wants_msvc_seh(tcx.sess)
76 // jump *into* cleanup - need a landing pad if GNU
77 (this.landing_pad_to(target), false)
79 (Some(_), None) => span_bug!(span, "{:?} - jump out of cleanup?", terminator),
80 (Some(_), Some(_)) => {
81 (this.landing_pad_to(target), true)
86 let llblock = |this: &mut Self, target: mir::BasicBlock| {
87 let (lltarget, is_cleanupret) = lltarget(this, target);
89 // MSVC cross-funclet jump - need a trampoline
91 debug!("llblock: creating cleanup trampoline for {:?}", target);
92 let name = &format!("{:?}_cleanup_trampoline_{:?}", bb, target);
93 let trampoline = this.new_block(name);
94 trampoline.cleanup_ret(cleanup_pad.unwrap(), Some(lltarget));
101 let funclet_br = |this: &mut Self, bx: Builder<'_, 'll, '_>, target: mir::BasicBlock| {
102 let (lltarget, is_cleanupret) = lltarget(this, target);
104 // micro-optimization: generate a `ret` rather than a jump
106 bx.cleanup_ret(cleanup_pad.unwrap(), Some(lltarget));
114 bx: Builder<'a, 'll, 'tcx>,
115 fn_ty: FnType<'tcx, Ty<'tcx>>,
117 llargs: &[&'ll Value],
118 destination: Option<(ReturnDest<'ll, 'tcx>, mir::BasicBlock)>,
119 cleanup: Option<mir::BasicBlock>
121 if let Some(cleanup) = cleanup {
122 let ret_bx = if let Some((_, target)) = destination {
125 this.unreachable_block()
127 let invokeret = bx.invoke(fn_ptr,
130 llblock(this, cleanup),
132 fn_ty.apply_attrs_callsite(&bx, invokeret);
134 if let Some((ret_dest, target)) = destination {
135 let ret_bx = this.build_block(target);
136 this.set_debug_loc(&ret_bx, terminator.source_info);
137 this.store_return(&ret_bx, ret_dest, &fn_ty.ret, invokeret);
140 let llret = bx.call(fn_ptr, &llargs, cleanup_bundle);
141 fn_ty.apply_attrs_callsite(&bx, llret);
142 if this.mir[bb].is_cleanup {
143 // Cleanup is always the cold path. Don't inline
144 // drop glue. Also, when there is a deeply-nested
145 // struct, there are "symmetry" issues that cause
146 // exponential inlining - see issue #41696.
147 llvm::Attribute::NoInline.apply_callsite(llvm::AttributePlace::Function, llret);
150 if let Some((ret_dest, target)) = destination {
151 this.store_return(&bx, ret_dest, &fn_ty.ret, llret);
152 funclet_br(this, bx, target);
159 self.set_debug_loc(&bx, terminator.source_info);
160 match terminator.kind {
161 mir::TerminatorKind::Resume => {
162 if let Some(cleanup_pad) = cleanup_pad {
163 bx.cleanup_ret(cleanup_pad, None);
165 let slot = self.get_personality_slot(&bx);
166 let lp0 = slot.project_field(&bx, 0).load(&bx).immediate();
167 let lp1 = slot.project_field(&bx, 1).load(&bx).immediate();
168 slot.storage_dead(&bx);
170 if !bx.sess().target.target.options.custom_unwind_resume {
171 let mut lp = C_undef(self.landing_pad_type());
172 lp = bx.insert_value(lp, lp0, 0);
173 lp = bx.insert_value(lp, lp1, 1);
176 bx.call(bx.cx.eh_unwind_resume(), &[lp0], cleanup_bundle);
182 mir::TerminatorKind::Abort => {
183 // Call core::intrinsics::abort()
184 let fnname = bx.cx.get_intrinsic(&("llvm.trap"));
185 bx.call(fnname, &[], None);
189 mir::TerminatorKind::Goto { target } => {
190 funclet_br(self, bx, target);
193 mir::TerminatorKind::SwitchInt { ref discr, switch_ty, ref values, ref targets } => {
194 let discr = self.codegen_operand(&bx, discr);
195 if targets.len() == 2 {
196 // If there are two targets, emit br instead of switch
197 let lltrue = llblock(self, targets[0]);
198 let llfalse = llblock(self, targets[1]);
199 if switch_ty == bx.tcx().types.bool {
200 // Don't generate trivial icmps when switching on bool
201 if let [0] = values[..] {
202 bx.cond_br(discr.immediate(), llfalse, lltrue);
204 assert_eq!(&values[..], &[1]);
205 bx.cond_br(discr.immediate(), lltrue, llfalse);
208 let switch_llty = bx.cx.layout_of(switch_ty).immediate_llvm_type(bx.cx);
209 let llval = C_uint_big(switch_llty, values[0]);
210 let cmp = bx.icmp(llvm::IntEQ, discr.immediate(), llval);
211 bx.cond_br(cmp, lltrue, llfalse);
214 let (otherwise, targets) = targets.split_last().unwrap();
215 let switch = bx.switch(discr.immediate(),
216 llblock(self, *otherwise), values.len());
217 let switch_llty = bx.cx.layout_of(switch_ty).immediate_llvm_type(bx.cx);
218 for (&value, target) in values.iter().zip(targets) {
219 let llval = C_uint_big(switch_llty, value);
220 let llbb = llblock(self, *target);
221 bx.add_case(switch, llval, llbb)
226 mir::TerminatorKind::Return => {
227 let llval = match self.fn_ty.ret.mode {
228 PassMode::Ignore | PassMode::Indirect(_) => {
233 PassMode::Direct(_) | PassMode::Pair(..) => {
234 let op = self.codegen_consume(&bx, &mir::Place::Local(mir::RETURN_PLACE));
235 if let Ref(llval, align) = op.val {
236 bx.load(llval, align)
238 op.immediate_or_packed_pair(&bx)
242 PassMode::Cast(cast_ty) => {
243 let op = match self.locals[mir::RETURN_PLACE] {
244 LocalRef::Operand(Some(op)) => op,
245 LocalRef::Operand(None) => bug!("use of return before def"),
246 LocalRef::Place(cg_place) => {
248 val: Ref(cg_place.llval, cg_place.align),
249 layout: cg_place.layout
253 let llslot = match op.val {
254 Immediate(_) | Pair(..) => {
255 let scratch = PlaceRef::alloca(&bx, self.fn_ty.ret.layout, "ret");
256 op.val.store(&bx, scratch);
259 Ref(llval, align) => {
260 assert_eq!(align.abi(), op.layout.align.abi(),
261 "return place is unaligned!");
266 bx.pointercast(llslot, cast_ty.llvm_type(bx.cx).ptr_to()),
267 self.fn_ty.ret.layout.align)
273 mir::TerminatorKind::Unreachable => {
277 mir::TerminatorKind::Drop { ref location, target, unwind } => {
278 let ty = location.ty(self.mir, bx.tcx()).to_ty(bx.tcx());
279 let ty = self.monomorphize(&ty);
280 let drop_fn = monomorphize::resolve_drop_in_place(bx.cx.tcx, ty);
282 if let ty::InstanceDef::DropGlue(_, None) = drop_fn.def {
283 // we don't actually need to drop anything.
284 funclet_br(self, bx, target);
288 let place = self.codegen_place(&bx, location);
290 let mut args = if let Some(llextra) = place.llextra {
291 args2 = [place.llval, llextra];
294 args1 = [place.llval];
297 let (drop_fn, fn_ty) = match ty.sty {
298 ty::TyDynamic(..) => {
299 let fn_ty = drop_fn.ty(bx.cx.tcx);
300 let sig = common::ty_fn_sig(bx.cx, fn_ty);
301 let sig = bx.tcx().normalize_erasing_late_bound_regions(
302 ty::ParamEnv::reveal_all(),
305 let fn_ty = FnType::new_vtable(bx.cx, sig, &[]);
306 let vtable = args[1];
308 (meth::DESTRUCTOR.get_fn(&bx, vtable, &fn_ty), fn_ty)
311 (callee::get_fn(bx.cx, drop_fn),
312 FnType::of_instance(bx.cx, &drop_fn))
315 do_call(self, bx, fn_ty, drop_fn, args,
316 Some((ReturnDest::Nothing, target)),
320 mir::TerminatorKind::Assert { ref cond, expected, ref msg, target, cleanup } => {
321 let cond = self.codegen_operand(&bx, cond).immediate();
322 let mut const_cond = common::const_to_opt_u128(cond, false).map(|c| c == 1);
324 // This case can currently arise only from functions marked
325 // with #[rustc_inherit_overflow_checks] and inlined from
326 // another crate (mostly core::num generic/#[inline] fns),
327 // while the current crate doesn't use overflow checks.
328 // NOTE: Unlike binops, negation doesn't have its own
329 // checked operation, just a comparison with the minimum
330 // value, so we have to check for the assert message.
331 if !bx.cx.check_overflow {
332 if let mir::interpret::EvalErrorKind::OverflowNeg = *msg {
333 const_cond = Some(expected);
337 // Don't codegen the panic block if success if known.
338 if const_cond == Some(expected) {
339 funclet_br(self, bx, target);
343 // Pass the condition through llvm.expect for branch hinting.
344 let expect = bx.cx.get_intrinsic(&"llvm.expect.i1");
345 let cond = bx.call(expect, &[cond, C_bool(bx.cx, expected)], None);
347 // Create the failure block and the conditional branch to it.
348 let lltarget = llblock(self, target);
349 let panic_block = self.new_block("panic");
351 bx.cond_br(cond, lltarget, panic_block.llbb());
353 bx.cond_br(cond, panic_block.llbb(), lltarget);
356 // After this point, bx is the block for the call to panic.
358 self.set_debug_loc(&bx, terminator.source_info);
360 // Get the location information.
361 let loc = bx.sess().codemap().lookup_char_pos(span.lo());
362 let filename = Symbol::intern(&loc.file.name.to_string()).as_str();
363 let filename = C_str_slice(bx.cx, filename);
364 let line = C_u32(bx.cx, loc.line as u32);
365 let col = C_u32(bx.cx, loc.col.to_usize() as u32 + 1);
366 let align = tcx.data_layout.aggregate_align
367 .max(tcx.data_layout.i32_align)
368 .max(tcx.data_layout.pointer_align);
370 // Put together the arguments to the panic entry point.
371 let (lang_item, args) = match *msg {
372 EvalErrorKind::BoundsCheck { ref len, ref index } => {
373 let len = self.codegen_operand(&mut bx, len).immediate();
374 let index = self.codegen_operand(&mut bx, index).immediate();
376 let file_line_col = C_struct(bx.cx, &[filename, line, col], false);
377 let file_line_col = consts::addr_of(bx.cx,
380 "panic_bounds_check_loc");
381 (lang_items::PanicBoundsCheckFnLangItem,
382 vec![file_line_col, index, len])
385 let str = msg.description();
386 let msg_str = Symbol::intern(str).as_str();
387 let msg_str = C_str_slice(bx.cx, msg_str);
388 let msg_file_line_col = C_struct(bx.cx,
389 &[msg_str, filename, line, col],
391 let msg_file_line_col = consts::addr_of(bx.cx,
395 (lang_items::PanicFnLangItem,
396 vec![msg_file_line_col])
400 // Obtain the panic entry point.
401 let def_id = common::langcall(bx.tcx(), Some(span), "", lang_item);
402 let instance = ty::Instance::mono(bx.tcx(), def_id);
403 let fn_ty = FnType::of_instance(bx.cx, &instance);
404 let llfn = callee::get_fn(bx.cx, instance);
406 // Codegen the actual panic invoke/call.
407 do_call(self, bx, fn_ty, llfn, &args, None, cleanup);
410 mir::TerminatorKind::DropAndReplace { .. } => {
411 bug!("undesugared DropAndReplace in codegen: {:?}", terminator);
414 mir::TerminatorKind::Call { ref func, ref args, ref destination, cleanup } => {
415 // Create the callee. This is a fn ptr or zero-sized and hence a kind of scalar.
416 let callee = self.codegen_operand(&bx, func);
418 let (instance, mut llfn) = match callee.layout.ty.sty {
419 ty::TyFnDef(def_id, substs) => {
420 (Some(ty::Instance::resolve(bx.cx.tcx,
421 ty::ParamEnv::reveal_all(),
427 (None, Some(callee.immediate()))
429 _ => bug!("{} is not callable", callee.layout.ty)
431 let def = instance.map(|i| i.def);
432 let sig = callee.layout.ty.fn_sig(bx.tcx());
433 let sig = bx.tcx().normalize_erasing_late_bound_regions(
434 ty::ParamEnv::reveal_all(),
439 // Handle intrinsics old codegen wants Expr's for, ourselves.
440 let intrinsic = match def {
441 Some(ty::InstanceDef::Intrinsic(def_id))
442 => Some(bx.tcx().item_name(def_id).as_str()),
445 let intrinsic = intrinsic.as_ref().map(|s| &s[..]);
447 if intrinsic == Some("transmute") {
448 if let Some(destination_ref) = destination.as_ref() {
449 let &(ref dest, target) = destination_ref;
450 self.codegen_transmute(&bx, &args[0], dest);
451 funclet_br(self, bx, target);
453 // If we are trying to transmute to an uninhabited type,
454 // it is likely there is no allotted destination. In fact,
455 // transmuting to an uninhabited type is UB, which means
456 // we can do what we like. Here, we declare that transmuting
457 // into an uninhabited type is impossible, so anything following
458 // it must be unreachable.
459 assert_eq!(bx.cx.layout_of(sig.output()).abi, layout::Abi::Uninhabited);
465 let extra_args = &args[sig.inputs().len()..];
466 let extra_args = extra_args.iter().map(|op_arg| {
467 let op_ty = op_arg.ty(self.mir, bx.tcx());
468 self.monomorphize(&op_ty)
469 }).collect::<Vec<_>>();
471 let fn_ty = match def {
472 Some(ty::InstanceDef::Virtual(..)) => {
473 FnType::new_vtable(bx.cx, sig, &extra_args)
475 Some(ty::InstanceDef::DropGlue(_, None)) => {
476 // empty drop glue - a nop.
477 let &(_, target) = destination.as_ref().unwrap();
478 funclet_br(self, bx, target);
481 _ => FnType::new(bx.cx, sig, &extra_args)
484 // The arguments we'll be passing. Plus one to account for outptr, if used.
485 let arg_count = fn_ty.args.len() + fn_ty.ret.is_indirect() as usize;
486 let mut llargs = Vec::with_capacity(arg_count);
488 // Prepare the return value destination
489 let ret_dest = if let Some((ref dest, _)) = *destination {
490 let is_intrinsic = intrinsic.is_some();
491 self.make_return_dest(&bx, dest, &fn_ty.ret, &mut llargs,
497 if intrinsic.is_some() && intrinsic != Some("drop_in_place") {
498 use intrinsic::codegen_intrinsic_call;
500 let dest = match ret_dest {
501 _ if fn_ty.ret.is_indirect() => llargs[0],
502 ReturnDest::Nothing => {
503 C_undef(fn_ty.ret.memory_ty(bx.cx).ptr_to())
505 ReturnDest::IndirectOperand(dst, _) |
506 ReturnDest::Store(dst) => dst.llval,
507 ReturnDest::DirectOperand(_) =>
508 bug!("Cannot use direct operand with an intrinsic call")
511 let args: Vec<_> = args.iter().enumerate().map(|(i, arg)| {
512 // The indices passed to simd_shuffle* in the
513 // third argument must be constant. This is
514 // checked by const-qualification, which also
515 // promotes any complex rvalues to constants.
516 if i == 2 && intrinsic.unwrap().starts_with("simd_shuffle") {
518 // The shuffle array argument is usually not an explicit constant,
519 // but specified directly in the code. This means it gets promoted
520 // and we can then extract the value by evaluating the promoted.
521 mir::Operand::Copy(mir::Place::Promoted(box(index, ty))) |
522 mir::Operand::Move(mir::Place::Promoted(box(index, ty))) => {
523 let param_env = ty::ParamEnv::reveal_all();
524 let cid = mir::interpret::GlobalId {
525 instance: self.instance,
526 promoted: Some(index),
528 let c = bx.tcx().const_eval(param_env.and(cid));
529 let (llval, ty) = self.simd_shuffle_indices(
531 terminator.source_info.span,
536 val: Immediate(llval),
537 layout: bx.cx.layout_of(ty),
541 mir::Operand::Copy(_) |
542 mir::Operand::Move(_) => {
543 span_bug!(span, "shuffle indices must be constant");
545 mir::Operand::Constant(ref constant) => {
546 let c = self.eval_mir_constant(&bx, constant);
547 let (llval, ty) = self.simd_shuffle_indices(
554 val: Immediate(llval),
555 layout: bx.cx.layout_of(ty)
561 self.codegen_operand(&bx, arg)
565 let callee_ty = instance.as_ref().unwrap().ty(bx.cx.tcx);
566 codegen_intrinsic_call(&bx, callee_ty, &fn_ty, &args, dest,
567 terminator.source_info.span);
569 if let ReturnDest::IndirectOperand(dst, _) = ret_dest {
570 self.store_return(&bx, ret_dest, &fn_ty.ret, dst.llval);
573 if let Some((_, target)) = *destination {
574 funclet_br(self, bx, target);
582 // Split the rust-call tupled arguments off.
583 let (first_args, untuple) = if abi == Abi::RustCall && !args.is_empty() {
584 let (tup, args) = args.split_last().unwrap();
590 for (i, arg) in first_args.iter().enumerate() {
591 let mut op = self.codegen_operand(&bx, arg);
592 if let (0, Some(ty::InstanceDef::Virtual(_, idx))) = (i, def) {
593 if let Pair(data_ptr, meta) = op.val {
594 llfn = Some(meth::VirtualIndex::from_index(idx)
595 .get_fn(&bx, meta, &fn_ty));
596 llargs.push(data_ptr);
601 // The callee needs to own the argument memory if we pass it
602 // by-ref, so make a local copy of non-immediate constants.
603 match (arg, op.val) {
604 (&mir::Operand::Copy(_), Ref(..)) |
605 (&mir::Operand::Constant(_), Ref(..)) => {
606 let tmp = PlaceRef::alloca(&bx, op.layout, "const");
607 op.val.store(&bx, tmp);
608 op.val = Ref(tmp.llval, tmp.align);
613 self.codegen_argument(&bx, op, &mut llargs, &fn_ty.args[i]);
615 if let Some(tup) = untuple {
616 self.codegen_arguments_untupled(&bx, tup, &mut llargs,
617 &fn_ty.args[first_args.len()..])
620 let fn_ptr = match (llfn, instance) {
621 (Some(llfn), _) => llfn,
622 (None, Some(instance)) => callee::get_fn(bx.cx, instance),
623 _ => span_bug!(span, "no llfn for call"),
626 do_call(self, bx, fn_ty, fn_ptr, &llargs,
627 destination.as_ref().map(|&(_, target)| (ret_dest, target)),
630 mir::TerminatorKind::GeneratorDrop |
631 mir::TerminatorKind::Yield { .. } => bug!("generator ops in codegen"),
632 mir::TerminatorKind::FalseEdges { .. } |
633 mir::TerminatorKind::FalseUnwind { .. } => bug!("borrowck false edges in codegen"),
637 fn codegen_argument(&mut self,
638 bx: &Builder<'a, 'll, 'tcx>,
639 op: OperandRef<'ll, 'tcx>,
640 llargs: &mut Vec<&'ll Value>,
641 arg: &ArgType<'tcx, Ty<'tcx>>) {
642 // Fill padding with undef value, where applicable.
643 if let Some(ty) = arg.pad {
644 llargs.push(C_undef(ty.llvm_type(bx.cx)));
651 if let PassMode::Pair(..) = arg.mode {
658 _ => bug!("codegen_argument: {:?} invalid for pair arugment", op)
662 // Force by-ref if we have to load through a cast pointer.
663 let (mut llval, align, by_ref) = match op.val {
664 Immediate(_) | Pair(..) => {
666 PassMode::Indirect(_) | PassMode::Cast(_) => {
667 let scratch = PlaceRef::alloca(bx, arg.layout, "arg");
668 op.val.store(bx, scratch);
669 (scratch.llval, scratch.align, true)
672 (op.immediate_or_packed_pair(bx), arg.layout.align, false)
676 Ref(llval, align) => {
677 if arg.is_indirect() && align.abi() < arg.layout.align.abi() {
678 // `foo(packed.large_field)`. We can't pass the (unaligned) field directly. I
679 // think that ATM (Rust 1.16) we only pass temporaries, but we shouldn't
680 // have scary latent bugs around.
682 let scratch = PlaceRef::alloca(bx, arg.layout, "arg");
683 base::memcpy_ty(bx, scratch.llval, llval, op.layout, align, MemFlags::empty());
684 (scratch.llval, scratch.align, true)
691 if by_ref && !arg.is_indirect() {
692 // Have to load the argument, maybe while casting it.
693 if let PassMode::Cast(ty) = arg.mode {
694 llval = bx.load(bx.pointercast(llval, ty.llvm_type(bx.cx).ptr_to()),
695 align.min(arg.layout.align));
697 // We can't use `PlaceRef::load` here because the argument
698 // may have a type we don't treat as immediate, but the ABI
699 // used for this call is passing it by-value. In that case,
700 // the load would just produce `OperandValue::Ref` instead
701 // of the `OperandValue::Immediate` we need for the call.
702 llval = bx.load(llval, align);
703 if let layout::Abi::Scalar(ref scalar) = arg.layout.abi {
704 if scalar.is_bool() {
705 bx.range_metadata(llval, 0..2);
708 // We store bools as i8 so we need to truncate to i1.
709 llval = base::to_immediate(bx, llval, arg.layout);
716 fn codegen_arguments_untupled(&mut self,
717 bx: &Builder<'a, 'll, 'tcx>,
718 operand: &mir::Operand<'tcx>,
719 llargs: &mut Vec<&'ll Value>,
720 args: &[ArgType<'tcx, Ty<'tcx>>]) {
721 let tuple = self.codegen_operand(bx, operand);
723 // Handle both by-ref and immediate tuples.
724 if let Ref(llval, align) = tuple.val {
725 let tuple_ptr = PlaceRef::new_sized(llval, tuple.layout, align);
726 for i in 0..tuple.layout.fields.count() {
727 let field_ptr = tuple_ptr.project_field(bx, i);
728 self.codegen_argument(bx, field_ptr.load(bx), llargs, &args[i]);
731 // If the tuple is immediate, the elements are as well.
732 for i in 0..tuple.layout.fields.count() {
733 let op = tuple.extract_field(bx, i);
734 self.codegen_argument(bx, op, llargs, &args[i]);
739 fn get_personality_slot(&mut self, bx: &Builder<'a, 'll, 'tcx>) -> PlaceRef<'ll, 'tcx> {
741 if let Some(slot) = self.personality_slot {
744 let layout = cx.layout_of(cx.tcx.intern_tup(&[
745 cx.tcx.mk_mut_ptr(cx.tcx.types.u8),
748 let slot = PlaceRef::alloca(bx, layout, "personalityslot");
749 self.personality_slot = Some(slot);
754 /// Return the landingpad wrapper around the given basic block
756 /// No-op in MSVC SEH scheme.
757 fn landing_pad_to(&mut self, target_bb: mir::BasicBlock) -> &'ll BasicBlock {
758 if let Some(block) = self.landing_pads[target_bb] {
762 let block = self.blocks[target_bb];
763 let landing_pad = self.landing_pad_uncached(block);
764 self.landing_pads[target_bb] = Some(landing_pad);
768 fn landing_pad_uncached(&mut self, target_bb: &'ll BasicBlock) -> &'ll BasicBlock {
769 if base::wants_msvc_seh(self.cx.sess()) {
770 span_bug!(self.mir.span, "landing pad was not inserted?")
773 let bx = self.new_block("cleanup");
775 let llpersonality = self.cx.eh_personality();
776 let llretty = self.landing_pad_type();
777 let lp = bx.landing_pad(llretty, llpersonality, 1);
780 let slot = self.get_personality_slot(&bx);
781 slot.storage_live(&bx);
782 Pair(bx.extract_value(lp, 0), bx.extract_value(lp, 1)).store(&bx, slot);
788 fn landing_pad_type(&self) -> &'ll Type {
790 Type::struct_(cx, &[Type::i8p(cx), Type::i32(cx)], false)
793 fn unreachable_block(&mut self) -> &'ll BasicBlock {
794 self.unreachable_block.unwrap_or_else(|| {
795 let bl = self.new_block("unreachable");
797 self.unreachable_block = Some(bl.llbb());
802 pub fn new_block(&self, name: &str) -> Builder<'a, 'll, 'tcx> {
803 Builder::new_block(self.cx, self.llfn, name)
806 pub fn build_block(&self, bb: mir::BasicBlock) -> Builder<'a, 'll, 'tcx> {
807 let bx = Builder::with_cx(self.cx);
808 bx.position_at_end(self.blocks[bb]);
812 fn make_return_dest(&mut self, bx: &Builder<'a, 'll, 'tcx>,
813 dest: &mir::Place<'tcx>, fn_ret: &ArgType<'tcx, Ty<'tcx>>,
814 llargs: &mut Vec<&'ll Value>, is_intrinsic: bool)
815 -> ReturnDest<'ll, 'tcx> {
816 // If the return is ignored, we can just return a do-nothing ReturnDest
817 if fn_ret.is_ignore() {
818 return ReturnDest::Nothing;
820 let dest = if let mir::Place::Local(index) = *dest {
821 match self.locals[index] {
822 LocalRef::Place(dest) => dest,
823 LocalRef::Operand(None) => {
824 // Handle temporary places, specifically Operand ones, as
825 // they don't have allocas
826 return if fn_ret.is_indirect() {
827 // Odd, but possible, case, we have an operand temporary,
828 // but the calling convention has an indirect return.
829 let tmp = PlaceRef::alloca(bx, fn_ret.layout, "tmp_ret");
830 tmp.storage_live(bx);
831 llargs.push(tmp.llval);
832 ReturnDest::IndirectOperand(tmp, index)
833 } else if is_intrinsic {
834 // Currently, intrinsics always need a location to store
835 // the result. so we create a temporary alloca for the
837 let tmp = PlaceRef::alloca(bx, fn_ret.layout, "tmp_ret");
838 tmp.storage_live(bx);
839 ReturnDest::IndirectOperand(tmp, index)
841 ReturnDest::DirectOperand(index)
844 LocalRef::Operand(Some(_)) => {
845 bug!("place local already assigned to");
849 self.codegen_place(bx, dest)
851 if fn_ret.is_indirect() {
852 if dest.align.abi() < dest.layout.align.abi() {
853 // Currently, MIR code generation does not create calls
854 // that store directly to fields of packed structs (in
855 // fact, the calls it creates write only to temps),
857 // If someone changes that, please update this code path
858 // to create a temporary.
859 span_bug!(self.mir.span, "can't directly store to unaligned value");
861 llargs.push(dest.llval);
864 ReturnDest::Store(dest)
868 fn codegen_transmute(&mut self, bx: &Builder<'a, 'll, 'tcx>,
869 src: &mir::Operand<'tcx>,
870 dst: &mir::Place<'tcx>) {
871 if let mir::Place::Local(index) = *dst {
872 match self.locals[index] {
873 LocalRef::Place(place) => self.codegen_transmute_into(bx, src, place),
874 LocalRef::Operand(None) => {
875 let dst_layout = bx.cx.layout_of(self.monomorphized_place_ty(dst));
876 assert!(!dst_layout.ty.has_erasable_regions());
877 let place = PlaceRef::alloca(bx, dst_layout, "transmute_temp");
878 place.storage_live(bx);
879 self.codegen_transmute_into(bx, src, place);
880 let op = place.load(bx);
881 place.storage_dead(bx);
882 self.locals[index] = LocalRef::Operand(Some(op));
884 LocalRef::Operand(Some(op)) => {
885 assert!(op.layout.is_zst(),
886 "assigning to initialized SSAtemp");
890 let dst = self.codegen_place(bx, dst);
891 self.codegen_transmute_into(bx, src, dst);
895 fn codegen_transmute_into(&mut self, bx: &Builder<'a, 'll, 'tcx>,
896 src: &mir::Operand<'tcx>,
897 dst: PlaceRef<'ll, 'tcx>) {
898 let src = self.codegen_operand(bx, src);
899 let llty = src.layout.llvm_type(bx.cx);
900 let cast_ptr = bx.pointercast(dst.llval, llty.ptr_to());
901 let align = src.layout.align.min(dst.layout.align);
902 src.val.store(bx, PlaceRef::new_sized(cast_ptr, src.layout, align));
906 // Stores the return value of a function call into it's final location.
907 fn store_return(&mut self,
908 bx: &Builder<'a, 'll, 'tcx>,
909 dest: ReturnDest<'ll, 'tcx>,
910 ret_ty: &ArgType<'tcx, Ty<'tcx>>,
912 use self::ReturnDest::*;
916 Store(dst) => ret_ty.store(bx, llval, dst),
917 IndirectOperand(tmp, index) => {
918 let op = tmp.load(bx);
919 tmp.storage_dead(bx);
920 self.locals[index] = LocalRef::Operand(Some(op));
922 DirectOperand(index) => {
923 // If there is a cast, we have to store and reload.
924 let op = if let PassMode::Cast(_) = ret_ty.mode {
925 let tmp = PlaceRef::alloca(bx, ret_ty.layout, "tmp_ret");
926 tmp.storage_live(bx);
927 ret_ty.store(bx, llval, tmp);
928 let op = tmp.load(bx);
929 tmp.storage_dead(bx);
932 OperandRef::from_immediate_or_packed_pair(bx, llval, ret_ty.layout)
934 self.locals[index] = LocalRef::Operand(Some(op));
940 enum ReturnDest<'ll, 'tcx> {
941 // Do nothing, the return value is indirect or ignored
943 // Store the return value to the pointer
944 Store(PlaceRef<'ll, 'tcx>),
945 // Stores an indirect return value to an operand local place
946 IndirectOperand(PlaceRef<'ll, 'tcx>, mir::Local),
947 // Stores a direct return value to an operand local place
948 DirectOperand(mir::Local)