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nagisanagisa
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Refine call terminator translation
* Implement landing pads; and * Implement DivergingCall translation; and * Modernise previous implementation of Call somewhat.
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‎src/librustc_trans/trans/mir/block.rs

Lines changed: 96 additions & 45 deletions
Original file line numberDiff line numberDiff line change
@@ -80,12 +80,12 @@ impl<'bcx, 'tcx> MirContext<'bcx, 'tcx> {
8080
}
8181

8282
mir::Terminator::Resume => {
83-
if let Some(llpersonalityslot) = self.llpersonalityslot {
84-
let lp = build::Load(bcx, llpersonalityslot);
85-
// FIXME(lifetime) base::call_lifetime_end(bcx, self.personality);
83+
if let Some(personalityslot) = self.llpersonalityslot {
84+
let lp = build::Load(bcx, personalityslot);
85+
base::call_lifetime_end(bcx, personalityslot);
8686
build::Resume(bcx, lp);
8787
} else {
88-
panic!("resume terminator without personality slot")
88+
panic!("resume terminator without personality slot set")
8989
}
9090
}
9191

@@ -94,33 +94,27 @@ impl<'bcx, 'tcx> MirContext<'bcx, 'tcx> {
9494
base::build_return_block(bcx.fcx, bcx, return_ty, DebugLoc::None);
9595
}
9696

97-
mir::Terminator::Call { ref data, targets } => {
97+
mir::Terminator::Call { ref func, ref args, ref destination, ref targets } => {
9898
// The location we'll write the result of the call into.
99-
let call_dest = self.trans_lvalue(bcx, &data.destination);
100-
99+
let call_dest = self.trans_lvalue(bcx, destination);
100+
let ret_ty = call_dest.ty.to_ty(bcx.tcx());
101101
// Create the callee. This will always be a fn
102102
// ptr and hence a kind of scalar.
103-
let callee = self.trans_operand(bcx, &data.func);
104-
let ret_ty = if let ty::TyBareFn(_, ref f) = callee.ty.sty {
105-
let sig = bcx.tcx().erase_late_bound_regions(&f.sig);
106-
let sig = infer::normalize_associated_type(bcx.tcx(), &sig);
107-
sig.output
103+
let callee = self.trans_operand(bcx, func);
104+
105+
// Does the fn use an outptr? If so, we have an extra first argument.
106+
let return_outptr = type_of::return_uses_outptr(bcx.ccx(), ret_ty);
107+
// The arguments we'll be passing.
108+
let mut llargs = if return_outptr {
109+
let mut vec = Vec::with_capacity(args.len() + 1);
110+
vec.push(call_dest.llval);
111+
vec
108112
} else {
109-
panic!("trans_block: expected TyBareFn as callee");
113+
Vec::with_capacity(args.len())
110114
};
111115

112-
// The arguments we'll be passing
113-
let mut llargs = vec![];
114-
115-
// Does the fn use an outptr? If so, that's the first arg.
116-
if let ty::FnConverging(ret_ty) = ret_ty {
117-
if type_of::return_uses_outptr(bcx.ccx(), ret_ty) {
118-
llargs.push(call_dest.llval);
119-
}
120-
}
121-
122116
// Process the rest of the args.
123-
for arg in &data.args {
117+
for arg in args {
124118
let arg_op = self.trans_operand(bcx, arg);
125119
match arg_op.val {
126120
Ref(llval) | Immediate(llval) => llargs.push(llval),
@@ -132,35 +126,92 @@ impl<'bcx, 'tcx> MirContext<'bcx, 'tcx> {
132126
}
133127
}
134128

135-
// FIXME: Handle panics
136-
//let panic_bb = self.llblock(targets.1);
137-
//self.make_landing_pad(panic_bb);
138-
139-
// Do the actual call.
140-
let (llret, b) = base::invoke(bcx,
141-
callee.immediate(),
142-
&llargs[..],
143-
callee.ty,
144-
DebugLoc::None);
145-
bcx = b;
146-
147-
// Copy the return value into the destination.
148-
if let ty::FnConverging(ret_ty) = ret_ty {
149-
if !type_of::return_uses_outptr(bcx.ccx(), ret_ty) &&
150-
!common::type_is_zero_size(bcx.ccx(), ret_ty) {
151-
base::store_ty(bcx, llret, call_dest.llval, ret_ty);
129+
let debugloc = DebugLoc::None;
130+
let attrs = attributes::from_fn_type(bcx.ccx(), callee.ty);
131+
match *targets {
132+
mir::CallTargets::Return(ret) => {
133+
let llret = build::Call(bcx,
134+
callee.immediate(),
135+
&llargs[..],
136+
Some(attrs),
137+
debugloc);
138+
if !return_outptr && !common::type_is_zero_size(bcx.ccx(), ret_ty) {
139+
base::store_ty(bcx, llret, call_dest.llval, ret_ty);
140+
}
141+
build::Br(bcx, self.llblock(ret), debugloc)
142+
}
143+
mir::CallTargets::WithCleanup((ret, cleanup)) => {
144+
let landingpad = self.make_landing_pad(cleanup);
145+
build::Invoke(bcx,
146+
callee.immediate(),
147+
&llargs[..],
148+
self.llblock(ret),
149+
landingpad.llbb,
150+
Some(attrs),
151+
debugloc);
152+
if !return_outptr && !common::type_is_zero_size(bcx.ccx(), ret_ty) {
153+
// FIXME: What do we do here?
154+
unimplemented!()
155+
}
152156
}
153157
}
154-
155-
build::Br(bcx, self.llblock(targets.0), DebugLoc::None)
156158
},
157159

158-
mir::Terminator::DivergingCall { .. } => {
159-
unimplemented!()
160+
mir::Terminator::DivergingCall { ref func, ref args, ref cleanup } => {
161+
let callee = self.trans_operand(bcx, func);
162+
let mut llargs = Vec::with_capacity(args.len());
163+
for arg in args {
164+
match self.trans_operand(bcx, arg).val {
165+
Ref(llval) | Immediate(llval) => llargs.push(llval),
166+
FatPtr(b, e) => {
167+
llargs.push(b);
168+
llargs.push(e);
169+
}
170+
}
171+
}
172+
let debugloc = DebugLoc::None;
173+
let attrs = attributes::from_fn_type(bcx.ccx(), callee.ty);
174+
match *cleanup {
175+
None => {
176+
build::Call(bcx, callee.immediate(), &llargs[..], Some(attrs), debugloc);
177+
build::Unreachable(bcx);
178+
}
179+
Some(cleanup) => {
180+
let landingpad = self.make_landing_pad(cleanup);
181+
let unreachable = self.unreachable_block();
182+
build::Invoke(bcx,
183+
callee.immediate(),
184+
&llargs[..],
185+
unreachable.llbb,
186+
landingpad.llbb,
187+
Some(attrs),
188+
debugloc);
189+
}
190+
}
160191
}
161192
}
162193
}
163194

195+
fn make_landing_pad(&mut self, cleanup: mir::BasicBlock) -> Block<'bcx, 'tcx> {
196+
let bcx = self.bcx(cleanup).fcx.new_block(true, "cleanup", None);
197+
let ccx = bcx.ccx();
198+
let llpersonality = bcx.fcx.eh_personality();
199+
let llretty = Type::struct_(ccx, &[Type::i8p(ccx), Type::i32(ccx)], false);
200+
let llretval = build::LandingPad(bcx, llretty, llpersonality, 1);
201+
build::SetCleanup(bcx, llretval);
202+
match self.llpersonalityslot {
203+
Some(slot) => build::Store(bcx, llretval, slot),
204+
None => {
205+
let personalityslot = base::alloca(bcx, llretty, "personalityslot");
206+
self.llpersonalityslot = Some(personalityslot);
207+
base::call_lifetime_start(bcx, personalityslot);
208+
build::Store(bcx, llretval, personalityslot)
209+
}
210+
};
211+
build::Br(bcx, self.llblock(cleanup), DebugLoc::None);
212+
bcx
213+
}
214+
164215
fn unreachable_block(&mut self) -> Block<'bcx, 'tcx> {
165216
match self.unreachable_block {
166217
Some(b) => b,

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