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Mutate llargs instead of reconstructing it.

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This commit is contained in:
Mark Simulacrum 2016-12-19 17:39:14 -07:00
parent 88202c5b83
commit 15c9e5e35b
1 changed files with 14 additions and 20 deletions
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34
src/librustc_trans/callee.rs
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@ -331,16 +331,21 @@ fn trans_fn_once_adapter_shim<'a, 'tcx>(
let fcx = FunctionContext::new(ccx, lloncefn, fn_ty);
let mut bcx = fcx.get_entry_block();
let callee = Callee {
data: Fn(llreffn),
ty: llref_fn_ty
};
// the first argument (`self`) will be the (by value) closure env.
let mut llargs = get_params(fcx.llfn);
let mut self_idx = fcx.fn_ty.ret.is_indirect() as usize;
let idx = fcx.fn_ty.ret.is_indirect() as usize;
let env_arg = &fcx.fn_ty.args[0];
let llenv = if env_arg.is_indirect() {
llargs[self_idx]
llargs[idx]
} else {
let scratch = alloc_ty(&bcx, closure_ty, "self");
let mut llarg_idx = self_idx;
let mut llarg_idx = idx;
env_arg.store_fn_arg(&bcx, &mut llarg_idx, scratch);
scratch
};
@ -349,35 +354,24 @@ fn trans_fn_once_adapter_shim<'a, 'tcx>(
// Adjust llargs such that llargs[self_idx..] has the call arguments.
// For zero-sized closures that means sneaking in a new argument.
if env_arg.is_ignore() {
if self_idx > 0 {
self_idx -= 1;
llargs[self_idx] = llenv;
if fcx.fn_ty.ret.is_indirect() {
llargs[0] = llenv;
} else {
llargs.insert(0, llenv);
}
} else {
llargs[self_idx] = llenv;
llargs[idx] = llenv;
}
let callee = Callee {
data: Fn(llreffn),
ty: llref_fn_ty
};
// Call the by-ref closure body with `self` in a cleanup scope,
// to drop `self` when the body returns, or in case it unwinds.
let self_scope = fcx.schedule_drop_mem(llenv, closure_ty);
let fn_ret = callee.ty.fn_ret();
let fn_ty = callee.direct_fn_type(bcx.ccx, &[]);
let first_llarg = if fn_ty.ret.is_indirect() && !fcx.fn_ty.ret.is_ignore() {
Some(get_param(fcx.llfn, 0))
} else {
None
};
let llargs = first_llarg.into_iter().chain(llargs[self_idx..].iter().cloned())
.collect::<Vec<_>>();
if fn_ty.ret.is_indirect() {
llargs.insert(0, get_param(fcx.llfn, 0));
}
let llfn = callee.reify(bcx.ccx);
let llret;
if let Some(landing_pad) = self_scope.landing_pad {