| use rustc::middle::lang_items; |
| use rustc::ty::{self, Ty, TypeFoldable, Instance}; |
| use rustc::ty::layout::{self, LayoutOf, HasTyCtxt, FnTypeExt}; |
| use rustc::mir::{self, Place, PlaceBase, Static, StaticKind}; |
| use rustc::mir::interpret::PanicInfo; |
| use rustc_target::abi::call::{ArgType, FnType, PassMode, IgnoreMode}; |
| use rustc_target::spec::abi::Abi; |
| use crate::base; |
| use crate::MemFlags; |
| use crate::common::{self, IntPredicate}; |
| use crate::meth; |
| |
| use crate::traits::*; |
| |
| use std::borrow::Cow; |
| |
| use syntax::symbol::Symbol; |
| use syntax_pos::Pos; |
| |
| use super::{FunctionCx, LocalRef}; |
| use super::place::PlaceRef; |
| use super::operand::OperandRef; |
| use super::operand::OperandValue::{Pair, Ref, Immediate}; |
| |
| /// Used by `FunctionCx::codegen_terminator` for emitting common patterns |
| /// e.g., creating a basic block, calling a function, etc. |
| struct TerminatorCodegenHelper<'a, 'tcx> { |
| bb: &'a mir::BasicBlock, |
| terminator: &'a mir::Terminator<'tcx>, |
| funclet_bb: Option<mir::BasicBlock>, |
| } |
| |
| impl<'a, 'tcx> TerminatorCodegenHelper<'a, 'tcx> { |
| /// Returns the associated funclet from `FunctionCx::funclets` for the |
| /// `funclet_bb` member if it is not `None`. |
| fn funclet<'c, 'b, Bx: BuilderMethods<'b, 'tcx>>( |
| &self, |
| fx: &'c mut FunctionCx<'b, 'tcx, Bx>, |
| ) -> Option<&'c Bx::Funclet> { |
| match self.funclet_bb { |
| Some(funcl) => fx.funclets[funcl].as_ref(), |
| None => None, |
| } |
| } |
| |
| fn lltarget<'b, 'c, Bx: BuilderMethods<'b, 'tcx>>( |
| &self, |
| fx: &'c mut FunctionCx<'b, 'tcx, Bx>, |
| target: mir::BasicBlock, |
| ) -> (Bx::BasicBlock, bool) { |
| let span = self.terminator.source_info.span; |
| let lltarget = fx.blocks[target]; |
| let target_funclet = fx.cleanup_kinds[target].funclet_bb(target); |
| match (self.funclet_bb, target_funclet) { |
| (None, None) => (lltarget, false), |
| (Some(f), Some(t_f)) if f == t_f || !base::wants_msvc_seh(fx.cx.tcx().sess) => |
| (lltarget, false), |
| // jump *into* cleanup - need a landing pad if GNU |
| (None, Some(_)) => (fx.landing_pad_to(target), false), |
| (Some(_), None) => span_bug!(span, "{:?} - jump out of cleanup?", self.terminator), |
| (Some(_), Some(_)) => (fx.landing_pad_to(target), true), |
| } |
| } |
| |
| /// Create a basic block. |
| fn llblock<'c, 'b, Bx: BuilderMethods<'b, 'tcx>>( |
| &self, |
| fx: &'c mut FunctionCx<'b, 'tcx, Bx>, |
| target: mir::BasicBlock, |
| ) -> Bx::BasicBlock { |
| let (lltarget, is_cleanupret) = self.lltarget(fx, target); |
| if is_cleanupret { |
| // MSVC cross-funclet jump - need a trampoline |
| |
| debug!("llblock: creating cleanup trampoline for {:?}", target); |
| let name = &format!("{:?}_cleanup_trampoline_{:?}", self.bb, target); |
| let mut trampoline = fx.new_block(name); |
| trampoline.cleanup_ret(self.funclet(fx).unwrap(), |
| Some(lltarget)); |
| trampoline.llbb() |
| } else { |
| lltarget |
| } |
| } |
| |
| fn funclet_br<'c, 'b, Bx: BuilderMethods<'b, 'tcx>>( |
| &self, |
| fx: &'c mut FunctionCx<'b, 'tcx, Bx>, |
| bx: &mut Bx, |
| target: mir::BasicBlock, |
| ) { |
| let (lltarget, is_cleanupret) = self.lltarget(fx, target); |
| if is_cleanupret { |
| // micro-optimization: generate a `ret` rather than a jump |
| // to a trampoline. |
| bx.cleanup_ret(self.funclet(fx).unwrap(), Some(lltarget)); |
| } else { |
| bx.br(lltarget); |
| } |
| } |
| |
| /// Call `fn_ptr` of `fn_ty` with the arguments `llargs`, the optional |
| /// return destination `destination` and the cleanup function `cleanup`. |
| fn do_call<'c, 'b, Bx: BuilderMethods<'b, 'tcx>>( |
| &self, |
| fx: &'c mut FunctionCx<'b, 'tcx, Bx>, |
| bx: &mut Bx, |
| fn_ty: FnType<'tcx, Ty<'tcx>>, |
| fn_ptr: Bx::Value, |
| llargs: &[Bx::Value], |
| destination: Option<(ReturnDest<'tcx, Bx::Value>, mir::BasicBlock)>, |
| cleanup: Option<mir::BasicBlock>, |
| ) { |
| if let Some(cleanup) = cleanup { |
| let ret_bx = if let Some((_, target)) = destination { |
| fx.blocks[target] |
| } else { |
| fx.unreachable_block() |
| }; |
| let invokeret = bx.invoke(fn_ptr, |
| &llargs, |
| ret_bx, |
| self.llblock(fx, cleanup), |
| self.funclet(fx)); |
| bx.apply_attrs_callsite(&fn_ty, invokeret); |
| |
| if let Some((ret_dest, target)) = destination { |
| let mut ret_bx = fx.build_block(target); |
| fx.set_debug_loc(&mut ret_bx, self.terminator.source_info); |
| fx.store_return(&mut ret_bx, ret_dest, &fn_ty.ret, invokeret); |
| } |
| } else { |
| let llret = bx.call(fn_ptr, &llargs, self.funclet(fx)); |
| bx.apply_attrs_callsite(&fn_ty, llret); |
| if fx.mir[*self.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. |
| bx.do_not_inline(llret); |
| } |
| |
| if let Some((ret_dest, target)) = destination { |
| fx.store_return(bx, ret_dest, &fn_ty.ret, llret); |
| self.funclet_br(fx, bx, target); |
| } else { |
| bx.unreachable(); |
| } |
| } |
| } |
| } |
| |
| /// Codegen implementations for some terminator variants. |
| impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { |
| /// Generates code for a `Resume` terminator. |
| fn codegen_resume_terminator<'b>( |
| &mut self, |
| helper: TerminatorCodegenHelper<'b, 'tcx>, |
| mut bx: Bx, |
| ) { |
| if let Some(funclet) = helper.funclet(self) { |
| bx.cleanup_ret(funclet, None); |
| } else { |
| let slot = self.get_personality_slot(&mut bx); |
| let lp0 = slot.project_field(&mut bx, 0); |
| let lp0 = bx.load_operand(lp0).immediate(); |
| let lp1 = slot.project_field(&mut bx, 1); |
| let lp1 = bx.load_operand(lp1).immediate(); |
| slot.storage_dead(&mut bx); |
| |
| if !bx.sess().target.target.options.custom_unwind_resume { |
| let mut lp = bx.const_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.eh_unwind_resume(), &[lp0], |
| helper.funclet(self)); |
| bx.unreachable(); |
| } |
| } |
| } |
| |
| fn codegen_switchint_terminator<'b>( |
| &mut self, |
| helper: TerminatorCodegenHelper<'b, 'tcx>, |
| mut bx: Bx, |
| discr: &mir::Operand<'tcx>, |
| switch_ty: Ty<'tcx>, |
| values: &Cow<'tcx, [u128]>, |
| targets: &Vec<mir::BasicBlock>, |
| ) { |
| let discr = self.codegen_operand(&mut bx, &discr); |
| if targets.len() == 2 { |
| // If there are two targets, emit br instead of switch |
| let lltrue = helper.llblock(self, targets[0]); |
| let llfalse = helper.llblock(self, targets[1]); |
| if switch_ty == bx.tcx().types.bool { |
| // Don't generate trivial icmps when switching on bool |
| if let [0] = values[..] { |
| bx.cond_br(discr.immediate(), llfalse, lltrue); |
| } else { |
| assert_eq!(&values[..], &[1]); |
| bx.cond_br(discr.immediate(), lltrue, llfalse); |
| } |
| } else { |
| let switch_llty = bx.immediate_backend_type( |
| bx.layout_of(switch_ty) |
| ); |
| let llval = bx.const_uint_big(switch_llty, values[0]); |
| let cmp = bx.icmp(IntPredicate::IntEQ, discr.immediate(), llval); |
| bx.cond_br(cmp, lltrue, llfalse); |
| } |
| } else { |
| let (otherwise, targets) = targets.split_last().unwrap(); |
| bx.switch( |
| discr.immediate(), |
| helper.llblock(self, *otherwise), |
| values.iter().zip(targets).map(|(&value, target)| { |
| (value, helper.llblock(self, *target)) |
| }) |
| ); |
| } |
| } |
| |
| fn codegen_return_terminator(&mut self, mut bx: Bx) { |
| if self.fn_ty.c_variadic { |
| match self.va_list_ref { |
| Some(va_list) => { |
| bx.va_end(va_list.llval); |
| } |
| None => { |
| bug!("C-variadic function must have a `va_list_ref`"); |
| } |
| } |
| } |
| if self.fn_ty.ret.layout.abi.is_uninhabited() { |
| // Functions with uninhabited return values are marked `noreturn`, |
| // so we should make sure that we never actually do. |
| bx.abort(); |
| bx.unreachable(); |
| return; |
| } |
| let llval = match self.fn_ty.ret.mode { |
| PassMode::Ignore(IgnoreMode::Zst) | PassMode::Indirect(..) => { |
| bx.ret_void(); |
| return; |
| } |
| |
| PassMode::Ignore(IgnoreMode::CVarArgs) => { |
| bug!("C-variadic arguments should never be the return type"); |
| } |
| |
| PassMode::Direct(_) | PassMode::Pair(..) => { |
| let op = |
| self.codegen_consume(&mut bx, &mir::Place::return_place().as_ref()); |
| if let Ref(llval, _, align) = op.val { |
| bx.load(llval, align) |
| } else { |
| op.immediate_or_packed_pair(&mut 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(cg_place) => { |
| OperandRef { |
| val: Ref(cg_place.llval, None, cg_place.align), |
| layout: cg_place.layout |
| } |
| } |
| LocalRef::UnsizedPlace(_) => bug!("return type must be sized"), |
| }; |
| let llslot = match op.val { |
| Immediate(_) | Pair(..) => { |
| let scratch = |
| PlaceRef::alloca(&mut bx, self.fn_ty.ret.layout); |
| op.val.store(&mut bx, scratch); |
| scratch.llval |
| } |
| Ref(llval, _, align) => { |
| assert_eq!(align, op.layout.align.abi, |
| "return place is unaligned!"); |
| llval |
| } |
| }; |
| let addr = bx.pointercast(llslot, bx.type_ptr_to( |
| bx.cast_backend_type(&cast_ty) |
| )); |
| bx.load(addr, self.fn_ty.ret.layout.align.abi) |
| } |
| }; |
| bx.ret(llval); |
| } |
| |
| |
| fn codegen_drop_terminator<'b>( |
| &mut self, |
| helper: TerminatorCodegenHelper<'b, 'tcx>, |
| mut bx: Bx, |
| location: &mir::Place<'tcx>, |
| target: mir::BasicBlock, |
| unwind: Option<mir::BasicBlock>, |
| ) { |
| let ty = location.ty(self.mir, bx.tcx()).ty; |
| let ty = self.monomorphize(&ty); |
| let drop_fn = Instance::resolve_drop_in_place(bx.tcx(), ty); |
| |
| if let ty::InstanceDef::DropGlue(_, None) = drop_fn.def { |
| // we don't actually need to drop anything. |
| helper.funclet_br(self, &mut bx, target); |
| return |
| } |
| |
| let place = self.codegen_place(&mut bx, &location.as_ref()); |
| let (args1, args2); |
| let mut args = if let Some(llextra) = place.llextra { |
| args2 = [place.llval, llextra]; |
| &args2[..] |
| } else { |
| args1 = [place.llval]; |
| &args1[..] |
| }; |
| let (drop_fn, fn_ty) = match ty.sty { |
| ty::Dynamic(..) => { |
| let sig = drop_fn.fn_sig(self.cx.tcx()); |
| let sig = self.cx.tcx().normalize_erasing_late_bound_regions( |
| ty::ParamEnv::reveal_all(), |
| &sig, |
| ); |
| let fn_ty = FnType::new_vtable(&bx, sig, &[]); |
| let vtable = args[1]; |
| args = &args[..1]; |
| (meth::DESTRUCTOR.get_fn(&mut bx, vtable, &fn_ty), fn_ty) |
| } |
| _ => { |
| (bx.get_fn(drop_fn), |
| FnType::of_instance(&bx, drop_fn)) |
| } |
| }; |
| helper.do_call(self, &mut bx, fn_ty, drop_fn, args, |
| Some((ReturnDest::Nothing, target)), |
| unwind); |
| } |
| |
| fn codegen_assert_terminator<'b>( |
| &mut self, |
| helper: TerminatorCodegenHelper<'b, 'tcx>, |
| mut bx: Bx, |
| terminator: &mir::Terminator<'tcx>, |
| cond: &mir::Operand<'tcx>, |
| expected: bool, |
| msg: &mir::AssertMessage<'tcx>, |
| target: mir::BasicBlock, |
| cleanup: Option<mir::BasicBlock>, |
| ) { |
| let span = terminator.source_info.span; |
| let cond = self.codegen_operand(&mut bx, cond).immediate(); |
| let mut const_cond = bx.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.check_overflow() { |
| if let PanicInfo::OverflowNeg = *msg { |
| const_cond = Some(expected); |
| } |
| } |
| |
| // Don't codegen the panic block if success if known. |
| if const_cond == Some(expected) { |
| helper.funclet_br(self, &mut bx, target); |
| return; |
| } |
| |
| // Pass the condition through llvm.expect for branch hinting. |
| let cond = bx.expect(cond, expected); |
| |
| // Create the failure block and the conditional branch to it. |
| let lltarget = helper.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(&mut bx, terminator.source_info); |
| |
| // Get the location information. |
| let loc = bx.sess().source_map().lookup_char_pos(span.lo()); |
| let filename = Symbol::intern(&loc.file.name.to_string()); |
| let line = bx.const_u32(loc.line as u32); |
| let col = bx.const_u32(loc.col.to_usize() as u32 + 1); |
| |
| // Put together the arguments to the panic entry point. |
| let (lang_item, args) = match msg { |
| PanicInfo::BoundsCheck { ref len, ref index } => { |
| let len = self.codegen_operand(&mut bx, len).immediate(); |
| let index = self.codegen_operand(&mut bx, index).immediate(); |
| |
| let file_line_col = bx.static_panic_msg( |
| None, |
| filename, |
| line, |
| col, |
| "panic_bounds_check_loc", |
| ); |
| (lang_items::PanicBoundsCheckFnLangItem, |
| vec![file_line_col, index, len]) |
| } |
| _ => { |
| let msg_str = Symbol::intern(msg.description()); |
| let msg_file_line_col = bx.static_panic_msg( |
| Some(msg_str), |
| filename, |
| line, |
| col, |
| "panic_loc", |
| ); |
| (lang_items::PanicFnLangItem, |
| vec![msg_file_line_col]) |
| } |
| }; |
| |
| // 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, instance); |
| let llfn = bx.get_fn(instance); |
| |
| // Codegen the actual panic invoke/call. |
| helper.do_call(self, &mut bx, fn_ty, llfn, &args, None, cleanup); |
| } |
| |
| fn codegen_call_terminator<'b>( |
| &mut self, |
| helper: TerminatorCodegenHelper<'b, 'tcx>, |
| mut bx: Bx, |
| terminator: &mir::Terminator<'tcx>, |
| func: &mir::Operand<'tcx>, |
| args: &Vec<mir::Operand<'tcx>>, |
| destination: &Option<(mir::Place<'tcx>, mir::BasicBlock)>, |
| cleanup: Option<mir::BasicBlock>, |
| ) { |
| let span = terminator.source_info.span; |
| // Create the callee. This is a fn ptr or zero-sized and hence a kind of scalar. |
| let callee = self.codegen_operand(&mut bx, func); |
| |
| let (instance, mut llfn) = match callee.layout.ty.sty { |
| ty::FnDef(def_id, substs) => { |
| (Some(ty::Instance::resolve(bx.tcx(), |
| ty::ParamEnv::reveal_all(), |
| def_id, |
| substs).unwrap()), |
| None) |
| } |
| ty::FnPtr(_) => { |
| (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().normalize_erasing_late_bound_regions( |
| ty::ParamEnv::reveal_all(), |
| &sig, |
| ); |
| let abi = sig.abi; |
| |
| // Handle intrinsics old codegen wants Expr's for, ourselves. |
| let intrinsic = match def { |
| Some(ty::InstanceDef::Intrinsic(def_id)) => |
| Some(bx.tcx().item_name(def_id).as_str()), |
| _ => None |
| }; |
| let intrinsic = intrinsic.as_ref().map(|s| &s[..]); |
| |
| if intrinsic == Some("transmute") { |
| if let Some(destination_ref) = destination.as_ref() { |
| let &(ref dest, target) = destination_ref; |
| self.codegen_transmute(&mut bx, &args[0], dest); |
| helper.funclet_br(self, &mut bx, target); |
| } else { |
| // If we are trying to transmute to an uninhabited type, |
| // it is likely there is no allotted destination. In fact, |
| // transmuting to an uninhabited type is UB, which means |
| // we can do what we like. Here, we declare that transmuting |
| // into an uninhabited type is impossible, so anything following |
| // it must be unreachable. |
| assert_eq!(bx.layout_of(sig.output()).abi, layout::Abi::Uninhabited); |
| bx.unreachable(); |
| } |
| return; |
| } |
| |
| // The "spoofed" `VaListImpl` added to a C-variadic functions signature |
| // should not be included in the `extra_args` calculation. |
| let extra_args_start_idx = sig.inputs().len() - if sig.c_variadic { 1 } else { 0 }; |
| let extra_args = &args[extra_args_start_idx..]; |
| 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, sig, &extra_args) |
| } |
| Some(ty::InstanceDef::DropGlue(_, None)) => { |
| // Empty drop glue; a no-op. |
| let &(_, target) = destination.as_ref().unwrap(); |
| helper.funclet_br(self, &mut bx, target); |
| return; |
| } |
| _ => FnType::new(&bx, sig, &extra_args) |
| }; |
| |
| // Emit a panic or a no-op for `panic_if_uninhabited`. |
| if intrinsic == Some("panic_if_uninhabited") { |
| let ty = instance.unwrap().substs.type_at(0); |
| let layout = bx.layout_of(ty); |
| if layout.abi.is_uninhabited() { |
| let loc = bx.sess().source_map().lookup_char_pos(span.lo()); |
| let filename = Symbol::intern(&loc.file.name.to_string()); |
| let line = bx.const_u32(loc.line as u32); |
| let col = bx.const_u32(loc.col.to_usize() as u32 + 1); |
| |
| let str = format!( |
| "Attempted to instantiate uninhabited type {}", |
| ty |
| ); |
| let msg_str = Symbol::intern(&str); |
| let msg_file_line_col = bx.static_panic_msg( |
| Some(msg_str), |
| filename, |
| line, |
| col, |
| "panic_loc", |
| ); |
| |
| // Obtain the panic entry point. |
| let def_id = |
| common::langcall(bx.tcx(), Some(span), "", lang_items::PanicFnLangItem); |
| let instance = ty::Instance::mono(bx.tcx(), def_id); |
| let fn_ty = FnType::of_instance(&bx, instance); |
| let llfn = bx.get_fn(instance); |
| |
| // Codegen the actual panic invoke/call. |
| helper.do_call( |
| self, |
| &mut bx, |
| fn_ty, |
| llfn, |
| &[msg_file_line_col], |
| destination.as_ref().map(|(_, bb)| (ReturnDest::Nothing, *bb)), |
| cleanup, |
| ); |
| } else { |
| // a NOP |
| helper.funclet_br(self, &mut bx, destination.as_ref().unwrap().1) |
| } |
| return; |
| } |
| |
| // 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(&mut bx, dest, &fn_ty.ret, &mut llargs, |
| is_intrinsic) |
| } else { |
| ReturnDest::Nothing |
| }; |
| |
| if intrinsic.is_some() && intrinsic != Some("drop_in_place") { |
| let dest = match ret_dest { |
| _ if fn_ty.ret.is_indirect() => llargs[0], |
| ReturnDest::Nothing => |
| bx.const_undef(bx.type_ptr_to(bx.memory_ty(&fn_ty.ret))), |
| 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 { |
| // The shuffle array argument is usually not an explicit constant, |
| // but specified directly in the code. This means it gets promoted |
| // and we can then extract the value by evaluating the promoted. |
| mir::Operand::Copy( |
| Place { |
| base: PlaceBase::Static(box Static { |
| kind: StaticKind::Promoted(promoted, _), |
| ty, |
| def_id: _, |
| }), |
| projection: box [], |
| } |
| ) | |
| mir::Operand::Move( |
| Place { |
| base: PlaceBase::Static(box Static { |
| kind: StaticKind::Promoted(promoted, _), |
| ty, |
| def_id: _, |
| }), |
| projection: box [], |
| } |
| ) => { |
| let param_env = ty::ParamEnv::reveal_all(); |
| let cid = mir::interpret::GlobalId { |
| instance: self.instance, |
| promoted: Some(promoted), |
| }; |
| let c = bx.tcx().const_eval(param_env.and(cid)); |
| let (llval, ty) = self.simd_shuffle_indices( |
| &bx, |
| terminator.source_info.span, |
| ty, |
| c, |
| ); |
| return OperandRef { |
| val: Immediate(llval), |
| layout: bx.layout_of(ty), |
| }; |
| |
| } |
| mir::Operand::Copy(_) | |
| mir::Operand::Move(_) => { |
| span_bug!(span, "shuffle indices must be constant"); |
| } |
| mir::Operand::Constant(ref constant) => { |
| let c = self.eval_mir_constant(constant); |
| let (llval, ty) = self.simd_shuffle_indices( |
| &bx, |
| constant.span, |
| constant.literal.ty, |
| c, |
| ); |
| return OperandRef { |
| val: Immediate(llval), |
| layout: bx.layout_of(ty) |
| }; |
| } |
| } |
| } |
| |
| self.codegen_operand(&mut bx, arg) |
| }).collect(); |
| |
| |
| bx.codegen_intrinsic_call(*instance.as_ref().unwrap(), &fn_ty, &args, dest, |
| terminator.source_info.span); |
| |
| if let ReturnDest::IndirectOperand(dst, _) = ret_dest { |
| self.store_return(&mut bx, ret_dest, &fn_ty.ret, dst.llval); |
| } |
| |
| if let Some((_, target)) = *destination { |
| helper.funclet_br(self, &mut 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) |
| }; |
| |
| // Useful determining if the current argument is the "spoofed" `VaListImpl` |
| let last_arg_idx = if sig.inputs().is_empty() { |
| None |
| } else { |
| Some(sig.inputs().len() - 1) |
| }; |
| 'make_args: for (i, arg) in first_args.iter().enumerate() { |
| // If this is a C-variadic function the function signature contains |
| // an "spoofed" `VaListImpl`. This argument is ignored, but we need to |
| // populate it with a dummy operand so that the users real arguments |
| // are not overwritten. |
| let i = if sig.c_variadic && last_arg_idx.map(|x| i >= x).unwrap_or(false) { |
| if i + 1 < fn_ty.args.len() { |
| i + 1 |
| } else { |
| break 'make_args |
| } |
| } else { |
| i |
| }; |
| let mut op = self.codegen_operand(&mut bx, arg); |
| |
| if let (0, Some(ty::InstanceDef::Virtual(_, idx))) = (i, def) { |
| if let Pair(..) = op.val { |
| // In the case of Rc<Self>, we need to explicitly pass a |
| // *mut RcBox<Self> with a Scalar (not ScalarPair) ABI. This is a hack |
| // that is understood elsewhere in the compiler as a method on |
| // `dyn Trait`. |
| // To get a `*mut RcBox<Self>`, we just keep unwrapping newtypes until |
| // we get a value of a built-in pointer type |
| 'descend_newtypes: while !op.layout.ty.is_unsafe_ptr() |
| && !op.layout.ty.is_region_ptr() |
| { |
| 'iter_fields: for i in 0..op.layout.fields.count() { |
| let field = op.extract_field(&mut bx, i); |
| if !field.layout.is_zst() { |
| // we found the one non-zero-sized field that is allowed |
| // now find *its* non-zero-sized field, or stop if it's a |
| // pointer |
| op = field; |
| continue 'descend_newtypes |
| } |
| } |
| |
| span_bug!(span, "receiver has no non-zero-sized fields {:?}", op); |
| } |
| |
| // now that we have `*dyn Trait` or `&dyn Trait`, split it up into its |
| // data pointer and vtable. Look up the method in the vtable, and pass |
| // the data pointer as the first argument |
| match op.val { |
| Pair(data_ptr, meta) => { |
| llfn = Some(meth::VirtualIndex::from_index(idx) |
| .get_fn(&mut bx, meta, &fn_ty)); |
| llargs.push(data_ptr); |
| continue 'make_args |
| } |
| other => bug!("expected a Pair, got {:?}", other), |
| } |
| } else if let Ref(data_ptr, Some(meta), _) = op.val { |
| // by-value dynamic dispatch |
| llfn = Some(meth::VirtualIndex::from_index(idx) |
| .get_fn(&mut bx, meta, &fn_ty)); |
| llargs.push(data_ptr); |
| continue; |
| } else { |
| span_bug!(span, "can't codegen a virtual call on {:?}", op); |
| } |
| } |
| |
| // 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(_, None, _)) | |
| (&mir::Operand::Constant(_), Ref(_, None, _)) => { |
| let tmp = PlaceRef::alloca(&mut bx, op.layout); |
| op.val.store(&mut bx, tmp); |
| op.val = Ref(tmp.llval, None, tmp.align); |
| } |
| _ => {} |
| } |
| |
| self.codegen_argument(&mut bx, op, &mut llargs, &fn_ty.args[i]); |
| } |
| if let Some(tup) = untuple { |
| self.codegen_arguments_untupled(&mut bx, tup, &mut llargs, |
| &fn_ty.args[first_args.len()..]) |
| } |
| |
| let fn_ptr = match (llfn, instance) { |
| (Some(llfn), _) => llfn, |
| (None, Some(instance)) => bx.get_fn(instance), |
| _ => span_bug!(span, "no llfn for call"), |
| }; |
| |
| helper.do_call(self, &mut bx, fn_ty, fn_ptr, &llargs, |
| destination.as_ref().map(|&(_, target)| (ret_dest, target)), |
| cleanup); |
| } |
| } |
| |
| impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { |
| pub fn codegen_block( |
| &mut self, |
| bb: mir::BasicBlock, |
| ) { |
| let mut bx = self.build_block(bb); |
| let data = &self.mir[bb]; |
| |
| debug!("codegen_block({:?}={:?})", bb, data); |
| |
| for statement in &data.statements { |
| bx = self.codegen_statement(bx, statement); |
| } |
| |
| self.codegen_terminator(bx, bb, data.terminator()); |
| } |
| |
| fn codegen_terminator( |
| &mut self, |
| mut bx: Bx, |
| bb: mir::BasicBlock, |
| terminator: &mir::Terminator<'tcx> |
| ) { |
| debug!("codegen_terminator: {:?}", terminator); |
| |
| // Create the cleanup bundle, if needed. |
| let funclet_bb = self.cleanup_kinds[bb].funclet_bb(bb); |
| let helper = TerminatorCodegenHelper { |
| bb: &bb, terminator, funclet_bb |
| }; |
| |
| self.set_debug_loc(&mut bx, terminator.source_info); |
| match terminator.kind { |
| mir::TerminatorKind::Resume => { |
| self.codegen_resume_terminator(helper, bx) |
| } |
| |
| mir::TerminatorKind::Abort => { |
| bx.abort(); |
| bx.unreachable(); |
| } |
| |
| mir::TerminatorKind::Goto { target } => { |
| helper.funclet_br(self, &mut bx, target); |
| } |
| |
| mir::TerminatorKind::SwitchInt { |
| ref discr, switch_ty, ref values, ref targets |
| } => { |
| self.codegen_switchint_terminator(helper, bx, discr, switch_ty, |
| values, targets); |
| } |
| |
| mir::TerminatorKind::Return => { |
| self.codegen_return_terminator(bx); |
| } |
| |
| mir::TerminatorKind::Unreachable => { |
| bx.unreachable(); |
| } |
| |
| mir::TerminatorKind::Drop { ref location, target, unwind } => { |
| self.codegen_drop_terminator(helper, bx, location, target, unwind); |
| } |
| |
| mir::TerminatorKind::Assert { ref cond, expected, ref msg, target, cleanup } => { |
| self.codegen_assert_terminator(helper, bx, terminator, cond, |
| expected, msg, target, cleanup); |
| } |
| |
| mir::TerminatorKind::DropAndReplace { .. } => { |
| bug!("undesugared DropAndReplace in codegen: {:?}", terminator); |
| } |
| |
| mir::TerminatorKind::Call { |
| ref func, |
| ref args, |
| ref destination, |
| cleanup, |
| from_hir_call: _ |
| } => { |
| self.codegen_call_terminator(helper, bx, terminator, func, |
| args, destination, cleanup); |
| } |
| mir::TerminatorKind::GeneratorDrop | |
| mir::TerminatorKind::Yield { .. } => bug!("generator ops in codegen"), |
| mir::TerminatorKind::FalseEdges { .. } | |
| mir::TerminatorKind::FalseUnwind { .. } => bug!("borrowck false edges in codegen"), |
| } |
| } |
| |
| fn codegen_argument( |
| &mut self, |
| bx: &mut Bx, |
| op: OperandRef<'tcx, Bx::Value>, |
| llargs: &mut Vec<Bx::Value>, |
| arg: &ArgType<'tcx, Ty<'tcx>> |
| ) { |
| // Fill padding with undef value, where applicable. |
| if let Some(ty) = arg.pad { |
| llargs.push(bx.const_undef(bx.reg_backend_type(&ty))) |
| } |
| |
| 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!("codegen_argument: {:?} invalid for pair argument", op) |
| } |
| } else if arg.is_unsized_indirect() { |
| match op.val { |
| Ref(a, Some(b), _) => { |
| llargs.push(a); |
| llargs.push(b); |
| return; |
| } |
| _ => bug!("codegen_argument: {:?} invalid for unsized indirect argument", 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); |
| op.val.store(bx, scratch); |
| (scratch.llval, scratch.align, true) |
| } |
| _ => { |
| (op.immediate_or_packed_pair(bx), arg.layout.align.abi, false) |
| } |
| } |
| } |
| Ref(llval, _, align) => { |
| if arg.is_indirect() && align < 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); |
| base::memcpy_ty(bx, scratch.llval, scratch.align, llval, align, |
| op.layout, MemFlags::empty()); |
| (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 { |
| let addr = bx.pointercast(llval, bx.type_ptr_to( |
| bx.cast_backend_type(&ty)) |
| ); |
| llval = bx.load(addr, align.min(arg.layout.align.abi)); |
| } 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 codegen_arguments_untupled( |
| &mut self, |
| bx: &mut Bx, |
| operand: &mir::Operand<'tcx>, |
| llargs: &mut Vec<Bx::Value>, |
| args: &[ArgType<'tcx, Ty<'tcx>>] |
| ) { |
| let tuple = self.codegen_operand(bx, operand); |
| |
| // Handle both by-ref and immediate tuples. |
| if let Ref(llval, None, align) = tuple.val { |
| let tuple_ptr = PlaceRef::new_sized_aligned(llval, tuple.layout, align); |
| for i in 0..tuple.layout.fields.count() { |
| let field_ptr = tuple_ptr.project_field(bx, i); |
| let field = bx.load_operand(field_ptr); |
| self.codegen_argument(bx, field, llargs, &args[i]); |
| } |
| } else if let Ref(_, Some(_), _) = tuple.val { |
| bug!("closure arguments must be sized") |
| } 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.codegen_argument(bx, op, llargs, &args[i]); |
| } |
| } |
| } |
| |
| fn get_personality_slot( |
| &mut self, |
| bx: &mut Bx |
| ) -> PlaceRef<'tcx, Bx::Value> { |
| 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 |
| ])); |
| let slot = PlaceRef::alloca(bx, layout); |
| self.personality_slot = Some(slot); |
| slot |
| } |
| } |
| |
| /// Returns the landing-pad wrapper around the given basic block. |
| /// |
| /// No-op in MSVC SEH scheme. |
| fn landing_pad_to( |
| &mut self, |
| target_bb: mir::BasicBlock |
| ) -> Bx::BasicBlock { |
| 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: Bx::BasicBlock |
| ) -> Bx::BasicBlock { |
| if base::wants_msvc_seh(self.cx.sess()) { |
| span_bug!(self.mir.span, "landing pad was not inserted?") |
| } |
| |
| let mut 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(&mut bx); |
| slot.storage_live(&mut bx); |
| Pair(bx.extract_value(lp, 0), bx.extract_value(lp, 1)).store(&mut bx, slot); |
| |
| bx.br(target_bb); |
| bx.llbb() |
| } |
| |
| fn landing_pad_type(&self) -> Bx::Type { |
| let cx = self.cx; |
| cx.type_struct(&[cx.type_i8p(), cx.type_i32()], false) |
| } |
| |
| fn unreachable_block( |
| &mut self |
| ) -> Bx::BasicBlock { |
| self.unreachable_block.unwrap_or_else(|| { |
| let mut bx = self.new_block("unreachable"); |
| bx.unreachable(); |
| self.unreachable_block = Some(bx.llbb()); |
| bx.llbb() |
| }) |
| } |
| |
| pub fn new_block(&self, name: &str) -> Bx { |
| Bx::new_block(self.cx, self.llfn, name) |
| } |
| |
| pub fn build_block( |
| &self, |
| bb: mir::BasicBlock |
| ) -> Bx { |
| let mut bx = Bx::with_cx(self.cx); |
| bx.position_at_end(self.blocks[bb]); |
| bx |
| } |
| |
| fn make_return_dest( |
| &mut self, |
| bx: &mut Bx, |
| dest: &mir::Place<'tcx>, |
| fn_ret: &ArgType<'tcx, Ty<'tcx>>, |
| llargs: &mut Vec<Bx::Value>, is_intrinsic: bool |
| ) -> ReturnDest<'tcx, Bx::Value> { |
| // 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 { |
| base: mir::PlaceBase::Local(index), |
| projection: box [], |
| } = *dest { |
| match self.locals[index] { |
| LocalRef::Place(dest) => dest, |
| LocalRef::UnsizedPlace(_) => bug!("return type must be sized"), |
| LocalRef::Operand(None) => { |
| // Handle temporary places, specifically `Operand` ones, as |
| // they don't have `alloca`s. |
| 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.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.storage_live(bx); |
| ReturnDest::IndirectOperand(tmp, index) |
| } else { |
| ReturnDest::DirectOperand(index) |
| }; |
| } |
| LocalRef::Operand(Some(_)) => { |
| bug!("place local already assigned to"); |
| } |
| } |
| } else { |
| self.codegen_place(bx, &mir::PlaceRef { |
| base: &dest.base, |
| projection: &dest.projection, |
| }) |
| }; |
| if fn_ret.is_indirect() { |
| if dest.align < 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 codegen_transmute( |
| &mut self, |
| bx: &mut Bx, |
| src: &mir::Operand<'tcx>, |
| dst: &mir::Place<'tcx> |
| ) { |
| if let mir::Place { |
| base: mir::PlaceBase::Local(index), |
| projection: box [], |
| } = *dst { |
| match self.locals[index] { |
| LocalRef::Place(place) => self.codegen_transmute_into(bx, src, place), |
| LocalRef::UnsizedPlace(_) => bug!("transmute must not involve unsized locals"), |
| LocalRef::Operand(None) => { |
| let dst_layout = bx.layout_of(self.monomorphized_place_ty(&dst.as_ref())); |
| assert!(!dst_layout.ty.has_erasable_regions()); |
| let place = PlaceRef::alloca(bx, dst_layout); |
| place.storage_live(bx); |
| self.codegen_transmute_into(bx, src, place); |
| let op = bx.load_operand(place); |
| 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.codegen_place(bx, &dst.as_ref()); |
| self.codegen_transmute_into(bx, src, dst); |
| } |
| } |
| |
| fn codegen_transmute_into( |
| &mut self, |
| bx: &mut Bx, |
| src: &mir::Operand<'tcx>, |
| dst: PlaceRef<'tcx, Bx::Value> |
| ) { |
| let src = self.codegen_operand(bx, src); |
| let llty = bx.backend_type(src.layout); |
| let cast_ptr = bx.pointercast(dst.llval, bx.type_ptr_to(llty)); |
| let align = src.layout.align.abi.min(dst.align); |
| src.val.store(bx, PlaceRef::new_sized_aligned(cast_ptr, src.layout, align)); |
| } |
| |
| |
| // Stores the return value of a function call into it's final location. |
| fn store_return( |
| &mut self, |
| bx: &mut Bx, |
| dest: ReturnDest<'tcx, Bx::Value>, |
| ret_ty: &ArgType<'tcx, Ty<'tcx>>, |
| llval: Bx::Value |
| ) { |
| use self::ReturnDest::*; |
| |
| match dest { |
| Nothing => (), |
| Store(dst) => bx.store_arg_ty(&ret_ty, llval, dst), |
| IndirectOperand(tmp, index) => { |
| let op = bx.load_operand(tmp); |
| 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.storage_live(bx); |
| bx.store_arg_ty(&ret_ty, llval, tmp); |
| let op = bx.load_operand(tmp); |
| 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, V> { |
| // Do nothing; the return value is indirect or ignored. |
| Nothing, |
| // Store the return value to the pointer. |
| Store(PlaceRef<'tcx, V>), |
| // Store an indirect return value to an operand local place. |
| IndirectOperand(PlaceRef<'tcx, V>, mir::Local), |
| // Store a direct return value to an operand local place. |
| DirectOperand(mir::Local) |
| } |
