From 012116f860eb5b859218640e963ba32545311a24 Mon Sep 17 00:00:00 2001
From: Adam Perry <adam.n.perry@gmail.com>
Date: Thu, 3 Oct 2019 19:10:34 -0700
Subject: [PATCH 01/12] Add InstanceDef::ReifyShim for track_caller functions.
---
src/librustc/mir/mono.rs | 1 +
src/librustc/ty/instance.rs | 7 +++++++
src/librustc/ty/mod.rs | 1 +
src/librustc/ty/structural_impls.rs | 5 ++++-
src/librustc_mir/interpret/terminator.rs | 1 +
src/librustc_mir/monomorphize/collector.rs | 2 ++
src/librustc_mir/monomorphize/partitioning.rs | 2 ++
src/librustc_mir/shim.rs | 9 +++++++++
8 files changed, 27 insertions(+), 1 deletion(-)
diff --git a/src/librustc/mir/mono.rs b/src/librustc/mir/mono.rs
index 313b2a5d50a30..265ac975ed7a2 100644
--- a/src/librustc/mir/mono.rs
+++ b/src/librustc/mir/mono.rs
@@ -386,6 +386,7 @@ impl<'tcx> CodegenUnit<'tcx> {
tcx.hir().as_local_hir_id(def_id)
}
InstanceDef::VtableShim(..) |
+ InstanceDef::ReifyShim(..) |
InstanceDef::Intrinsic(..) |
InstanceDef::FnPtrShim(..) |
InstanceDef::Virtual(..) |
diff --git a/src/librustc/ty/instance.rs b/src/librustc/ty/instance.rs
index 93a8341e74628..e13e097b482f7 100644
--- a/src/librustc/ty/instance.rs
+++ b/src/librustc/ty/instance.rs
@@ -25,6 +25,9 @@ pub enum InstanceDef<'tcx> {
/// `<T as Trait>::method` where `method` receives unsizeable `self: Self`.
VtableShim(DefId),
+ /// `fn()` where the function is annotated with `#[track_caller]`.
+ ReifyShim(DefId),
+
/// `<fn() as FnTrait>::call_*`
/// `DefId` is `FnTrait::call_*`
FnPtrShim(DefId, Ty<'tcx>),
@@ -123,6 +126,7 @@ impl<'tcx> InstanceDef<'tcx> {
match *self {
InstanceDef::Item(def_id) |
InstanceDef::VtableShim(def_id) |
+ InstanceDef::ReifyShim(def_id) |
InstanceDef::FnPtrShim(def_id, _) |
InstanceDef::Virtual(def_id, _) |
InstanceDef::Intrinsic(def_id, ) |
@@ -178,6 +182,9 @@ impl<'tcx> fmt::Display for Instance<'tcx> {
InstanceDef::VtableShim(_) => {
write!(f, " - shim(vtable)")
}
+ InstanceDef::ReifyShim(_) => {
+ write!(f, " - shim(reify)")
+ }
InstanceDef::Intrinsic(_) => {
write!(f, " - intrinsic")
}
diff --git a/src/librustc/ty/mod.rs b/src/librustc/ty/mod.rs
index cfd859c33c2ef..3692caada577c 100644
--- a/src/librustc/ty/mod.rs
+++ b/src/librustc/ty/mod.rs
@@ -3026,6 +3026,7 @@ impl<'tcx> TyCtxt<'tcx> {
self.optimized_mir(did)
}
ty::InstanceDef::VtableShim(..) |
+ ty::InstanceDef::ReifyShim(..) |
ty::InstanceDef::Intrinsic(..) |
ty::InstanceDef::FnPtrShim(..) |
ty::InstanceDef::Virtual(..) |
diff --git a/src/librustc/ty/structural_impls.rs b/src/librustc/ty/structural_impls.rs
index 5aa59cc309fc7..8945e1a1debdb 100644
--- a/src/librustc/ty/structural_impls.rs
+++ b/src/librustc/ty/structural_impls.rs
@@ -761,6 +761,8 @@ impl<'a, 'tcx> Lift<'tcx> for ty::InstanceDef<'a> {
Some(ty::InstanceDef::Item(def_id)),
ty::InstanceDef::VtableShim(def_id) =>
Some(ty::InstanceDef::VtableShim(def_id)),
+ ty::InstanceDef::ReifyShim(def_id) =>
+ Some(ty::InstanceDef::ReifyShim(def_id)),
ty::InstanceDef::Intrinsic(def_id) =>
Some(ty::InstanceDef::Intrinsic(def_id)),
ty::InstanceDef::FnPtrShim(def_id, ref ty) =>
@@ -966,6 +968,7 @@ impl<'tcx> TypeFoldable<'tcx> for ty::instance::Instance<'tcx> {
def: match self.def {
Item(did) => Item(did.fold_with(folder)),
VtableShim(did) => VtableShim(did.fold_with(folder)),
+ ReifyShim(did) => ReifyShim(did.fold_with(folder)),
Intrinsic(did) => Intrinsic(did.fold_with(folder)),
FnPtrShim(did, ty) => FnPtrShim(
did.fold_with(folder),
@@ -994,7 +997,7 @@ impl<'tcx> TypeFoldable<'tcx> for ty::instance::Instance<'tcx> {
use crate::ty::InstanceDef::*;
self.substs.visit_with(visitor) ||
match self.def {
- Item(did) | VtableShim(did) | Intrinsic(did) | Virtual(did, _) => {
+ Item(did) | VtableShim(did) | ReifyShim(did) | Intrinsic(did) | Virtual(did, _) => {
did.visit_with(visitor)
},
FnPtrShim(did, ty) | CloneShim(did, ty) => {
diff --git a/src/librustc_mir/interpret/terminator.rs b/src/librustc_mir/interpret/terminator.rs
index ef6b7d626e7a4..11c7cd0d901d0 100644
--- a/src/librustc_mir/interpret/terminator.rs
+++ b/src/librustc_mir/interpret/terminator.rs
@@ -263,6 +263,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
Ok(())
}
ty::InstanceDef::VtableShim(..) |
+ ty::InstanceDef::ReifyShim(..) |
ty::InstanceDef::ClosureOnceShim { .. } |
ty::InstanceDef::FnPtrShim(..) |
ty::InstanceDef::DropGlue(..) |
diff --git a/src/librustc_mir/monomorphize/collector.rs b/src/librustc_mir/monomorphize/collector.rs
index 3f0a2674305d4..07ae4837d1cb3 100644
--- a/src/librustc_mir/monomorphize/collector.rs
+++ b/src/librustc_mir/monomorphize/collector.rs
@@ -747,6 +747,7 @@ fn visit_instance_use<'tcx>(
}
}
ty::InstanceDef::VtableShim(..) |
+ ty::InstanceDef::ReifyShim(..) |
ty::InstanceDef::Virtual(..) |
ty::InstanceDef::DropGlue(_, None) => {
// don't need to emit shim if we are calling directly.
@@ -773,6 +774,7 @@ fn should_monomorphize_locally<'tcx>(tcx: TyCtxt<'tcx>, instance: &Instance<'tcx
let def_id = match instance.def {
ty::InstanceDef::Item(def_id) => def_id,
ty::InstanceDef::VtableShim(..) |
+ ty::InstanceDef::ReifyShim(..) |
ty::InstanceDef::ClosureOnceShim { .. } |
ty::InstanceDef::Virtual(..) |
ty::InstanceDef::FnPtrShim(..) |
diff --git a/src/librustc_mir/monomorphize/partitioning.rs b/src/librustc_mir/monomorphize/partitioning.rs
index 6d9dae7214cc2..b9d38028b72a8 100644
--- a/src/librustc_mir/monomorphize/partitioning.rs
+++ b/src/librustc_mir/monomorphize/partitioning.rs
@@ -339,6 +339,7 @@ fn mono_item_visibility(
// These are all compiler glue and such, never exported, always hidden.
InstanceDef::VtableShim(..) |
+ InstanceDef::ReifyShim(..) |
InstanceDef::FnPtrShim(..) |
InstanceDef::Virtual(..) |
InstanceDef::Intrinsic(..) |
@@ -677,6 +678,7 @@ fn characteristic_def_id_of_mono_item<'tcx>(
let def_id = match instance.def {
ty::InstanceDef::Item(def_id) => def_id,
ty::InstanceDef::VtableShim(..) |
+ ty::InstanceDef::ReifyShim(..) |
ty::InstanceDef::FnPtrShim(..) |
ty::InstanceDef::ClosureOnceShim { .. } |
ty::InstanceDef::Intrinsic(..) |
diff --git a/src/librustc_mir/shim.rs b/src/librustc_mir/shim.rs
index 78008e2fcd361..10240271eb8ea 100644
--- a/src/librustc_mir/shim.rs
+++ b/src/librustc_mir/shim.rs
@@ -41,6 +41,15 @@ fn make_shim<'tcx>(tcx: TyCtxt<'tcx>, instance: ty::InstanceDef<'tcx>) -> &'tcx
None,
)
}
+ ty::InstanceDef::ReifyShim(def_id) => {
+ build_call_shim(
+ tcx,
+ def_id,
+ Adjustment::DerefMove,
+ CallKind::Direct(def_id),
+ None,
+ )
+ }
ty::InstanceDef::FnPtrShim(def_id, ty) => {
let trait_ = tcx.trait_of_item(def_id).unwrap();
let adjustment = match tcx.lang_items().fn_trait_kind(trait_) {
From f5f67e78bb3bfbc391699021c89b07f1aff3aa26 Mon Sep 17 00:00:00 2001
From: Adam Perry <adam.n.perry@gmail.com>
Date: Sat, 5 Oct 2019 14:24:07 -0700
Subject: [PATCH 02/12] Add Instance::resolve_for_fn_ptr
---
src/librustc/ty/instance.rs | 24 +++++++++++++++++++++++-
1 file changed, 23 insertions(+), 1 deletion(-)
diff --git a/src/librustc/ty/instance.rs b/src/librustc/ty/instance.rs
index e13e097b482f7..f547da00b1ad9 100644
--- a/src/librustc/ty/instance.rs
+++ b/src/librustc/ty/instance.rs
@@ -25,7 +25,7 @@ pub enum InstanceDef<'tcx> {
/// `<T as Trait>::method` where `method` receives unsizeable `self: Self`.
VtableShim(DefId),
- /// `fn()` where the function is annotated with `#[track_caller]`.
+ /// `fn()` pointer where the function is annotated with `#[track_caller]`.
ReifyShim(DefId),
/// `<fn() as FnTrait>::call_*`
@@ -297,6 +297,28 @@ impl<'tcx> Instance<'tcx> {
result
}
+ pub fn resolve_for_fn_ptr(
+ tcx: TyCtxt<'tcx>,
+ param_env: ty::ParamEnv<'tcx>,
+ def_id: DefId,
+ substs: SubstsRef<'tcx>,
+ ) -> Option<Instance<'tcx>> {
+ debug!("resolve(def_id={:?}, substs={:?})", def_id, substs);
+ let fn_sig = tcx.fn_sig(def_id);
+ // let is_reify_shim = fn_sig.inputs().skip_binder().len() > 0
+ // && fn_sig.input(0).skip_binder().is_param(0)
+ // && tcx.generics_of(def_id).has_self;
+ if is_reify_shim {
+ debug!(" => fn ptr with implicit caller location");
+ Some(Instance {
+ def: InstanceDef::ReifyShim(def_id),
+ substs,
+ })
+ } else {
+ Instance::resolve(tcx, param_env, def_id, substs)
+ }
+ }
+
pub fn resolve_for_vtable(
tcx: TyCtxt<'tcx>,
param_env: ty::ParamEnv<'tcx>,
From 01327384370b81e3a155dc70a2533935c4495db8 Mon Sep 17 00:00:00 2001
From: Adam Perry <adam.n.perry@gmail.com>
Date: Wed, 9 Oct 2019 06:05:49 -0700
Subject: [PATCH 03/12] Reifying callers of Instance::resolve use
resolve_for_fn_ptr.
---
src/librustc/ty/instance.rs | 9 +++------
src/librustc_codegen_ssa/callee.rs | 17 +++++++++++++++++
src/librustc_codegen_ssa/mir/rvalue.rs | 2 +-
src/librustc_mir/monomorphize/collector.rs | 10 ++++++----
src/librustc_mir/shim.rs | 2 +-
5 files changed, 28 insertions(+), 12 deletions(-)
diff --git a/src/librustc/ty/instance.rs b/src/librustc/ty/instance.rs
index f547da00b1ad9..471bd1637546c 100644
--- a/src/librustc/ty/instance.rs
+++ b/src/librustc/ty/instance.rs
@@ -1,3 +1,4 @@
+// use crate::hir::CodegenFnAttrFlags;
use crate::hir::Unsafety;
use crate::hir::def::Namespace;
use crate::hir::def_id::DefId;
@@ -304,12 +305,8 @@ impl<'tcx> Instance<'tcx> {
substs: SubstsRef<'tcx>,
) -> Option<Instance<'tcx>> {
debug!("resolve(def_id={:?}, substs={:?})", def_id, substs);
- let fn_sig = tcx.fn_sig(def_id);
- // let is_reify_shim = fn_sig.inputs().skip_binder().len() > 0
- // && fn_sig.input(0).skip_binder().is_param(0)
- // && tcx.generics_of(def_id).has_self;
- if is_reify_shim {
- debug!(" => fn ptr with implicit caller location");
+ if false {
+ debug!(" => fn pointer created for function with #[track_caller]");
Some(Instance {
def: InstanceDef::ReifyShim(def_id),
substs,
diff --git a/src/librustc_codegen_ssa/callee.rs b/src/librustc_codegen_ssa/callee.rs
index 4744dd6302fb3..6ba6774cbf881 100644
--- a/src/librustc_codegen_ssa/callee.rs
+++ b/src/librustc_codegen_ssa/callee.rs
@@ -18,6 +18,23 @@ pub fn resolve_and_get_fn<'tcx, Cx: CodegenMethods<'tcx>>(
)
}
+pub fn resolve_and_get_fn_for_ptr<'tcx,
+ Cx: Backend<'tcx> + MiscMethods<'tcx> + TypeMethods<'tcx>
+>(
+ cx: &Cx,
+ def_id: DefId,
+ substs: SubstsRef<'tcx>,
+) -> Cx::Value {
+ cx.get_fn(
+ ty::Instance::resolve_for_fn_ptr(
+ cx.tcx(),
+ ty::ParamEnv::reveal_all(),
+ def_id,
+ substs
+ ).unwrap()
+ )
+}
+
pub fn resolve_and_get_fn_for_vtable<'tcx,
Cx: Backend<'tcx> + MiscMethods<'tcx> + TypeMethods<'tcx>
>(
diff --git a/src/librustc_codegen_ssa/mir/rvalue.rs b/src/librustc_codegen_ssa/mir/rvalue.rs
index 6ffa561f3fecf..978e7218aa745 100644
--- a/src/librustc_codegen_ssa/mir/rvalue.rs
+++ b/src/librustc_codegen_ssa/mir/rvalue.rs
@@ -190,7 +190,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
bug!("reifying a fn ptr that requires const arguments");
}
OperandValue::Immediate(
- callee::resolve_and_get_fn(bx.cx(), def_id, substs))
+ callee::resolve_and_get_fn_for_ptr(bx.cx(), def_id, substs))
}
_ => {
bug!("{} cannot be reified to a fn ptr", operand.layout.ty)
diff --git a/src/librustc_mir/monomorphize/collector.rs b/src/librustc_mir/monomorphize/collector.rs
index 07ae4837d1cb3..a1f5562035c69 100644
--- a/src/librustc_mir/monomorphize/collector.rs
+++ b/src/librustc_mir/monomorphize/collector.rs
@@ -721,10 +721,12 @@ fn visit_fn_use<'tcx>(
output: &mut Vec<MonoItem<'tcx>>,
) {
if let ty::FnDef(def_id, substs) = ty.kind {
- let instance = ty::Instance::resolve(tcx,
- ty::ParamEnv::reveal_all(),
- def_id,
- substs).unwrap();
+ let resolver = if is_direct_call {
+ ty::Instance::resolve
+ } else {
+ ty::Instance::resolve_for_fn_ptr
+ };
+ let instance = resolver(tcx, ty::ParamEnv::reveal_all(), def_id, substs).unwrap();
visit_instance_use(tcx, instance, is_direct_call, output);
}
}
diff --git a/src/librustc_mir/shim.rs b/src/librustc_mir/shim.rs
index 10240271eb8ea..eced7eb09ae87 100644
--- a/src/librustc_mir/shim.rs
+++ b/src/librustc_mir/shim.rs
@@ -45,7 +45,7 @@ fn make_shim<'tcx>(tcx: TyCtxt<'tcx>, instance: ty::InstanceDef<'tcx>) -> &'tcx
build_call_shim(
tcx,
def_id,
- Adjustment::DerefMove,
+ Adjustment::Identity, // TODO(anp) is this the right kind of adjustment?
CallKind::Direct(def_id),
None,
)
From b8414c13abf9dc994f9c0dccee848a8b0fb1b061 Mon Sep 17 00:00:00 2001
From: Adam Perry <adam.n.perry@gmail.com>
Date: Wed, 9 Oct 2019 06:20:23 -0700
Subject: [PATCH 04/12] Return ReifyShim from Instance::resolve_for_fn_ptr when
track_caller present.
This ICEs in MIR currently, which I think is to be expected since none of the MIR plumbing is set up. I added a test which confirms that the shim is being used for reifying a track_caller function.
---
src/librustc/ty/instance.rs | 4 ++--
.../taking-fn-pointer.rs | 16 ++++++++++++++
.../taking-fn-pointer.stderr | 21 +++++++++++++++++++
3 files changed, 39 insertions(+), 2 deletions(-)
create mode 100644 src/test/ui/rfc-2091-track-caller/taking-fn-pointer.rs
create mode 100644 src/test/ui/rfc-2091-track-caller/taking-fn-pointer.stderr
diff --git a/src/librustc/ty/instance.rs b/src/librustc/ty/instance.rs
index 471bd1637546c..18b625984e1a2 100644
--- a/src/librustc/ty/instance.rs
+++ b/src/librustc/ty/instance.rs
@@ -1,4 +1,4 @@
-// use crate::hir::CodegenFnAttrFlags;
+use crate::hir::CodegenFnAttrFlags;
use crate::hir::Unsafety;
use crate::hir::def::Namespace;
use crate::hir::def_id::DefId;
@@ -305,7 +305,7 @@ impl<'tcx> Instance<'tcx> {
substs: SubstsRef<'tcx>,
) -> Option<Instance<'tcx>> {
debug!("resolve(def_id={:?}, substs={:?})", def_id, substs);
- if false {
+ if tcx.codegen_fn_attrs(def_id).flags.contains(CodegenFnAttrFlags::TRACK_CALLER) {
debug!(" => fn pointer created for function with #[track_caller]");
Some(Instance {
def: InstanceDef::ReifyShim(def_id),
diff --git a/src/test/ui/rfc-2091-track-caller/taking-fn-pointer.rs b/src/test/ui/rfc-2091-track-caller/taking-fn-pointer.rs
new file mode 100644
index 0000000000000..df3893f2a6a19
--- /dev/null
+++ b/src/test/ui/rfc-2091-track-caller/taking-fn-pointer.rs
@@ -0,0 +1,16 @@
+// failure-status: 101
+// normalize-stderr-test "note: rustc 1.* running on .*" -> "note: rustc VERSION running on TARGET"
+// normalize-stderr-test "note: compiler flags: .*" -> "note: compiler flags: FLAGS"
+
+#![feature(track_caller)] //~ WARN the feature `track_caller` is incomplete
+
+#[track_caller]
+fn f() {}
+
+fn call_it(x: fn()) {
+ x();
+}
+
+fn main() {
+ call_it(f);
+}
\ No newline at end of file
diff --git a/src/test/ui/rfc-2091-track-caller/taking-fn-pointer.stderr b/src/test/ui/rfc-2091-track-caller/taking-fn-pointer.stderr
new file mode 100644
index 0000000000000..fb625ae116e7c
--- /dev/null
+++ b/src/test/ui/rfc-2091-track-caller/taking-fn-pointer.stderr
@@ -0,0 +1,21 @@
+warning: the feature `track_caller` is incomplete and may cause the compiler to crash
+ --> $DIR/taking-fn-pointer.rs:5:12
+ |
+LL | #![feature(track_caller)]
+ | ^^^^^^^^^^^^
+ |
+ = note: `#[warn(incomplete_features)]` on by default
+
+thread 'rustc' panicked at 'index out of bounds: the len is 1 but the index is 1', $SRC_DIR/libcore/slice/mod.rs:LL:COL
+note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
+
+error: internal compiler error: unexpected panic
+
+note: the compiler unexpectedly panicked. this is a bug.
+
+note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
+
+note: rustc VERSION running on TARGET
+
+note: compiler flags: FLAGS
+
From 8a097f26198d9979d88e7c0cd0a3bce283ff038a Mon Sep 17 00:00:00 2001
From: Adam Perry <adam.n.perry@gmail.com>
Date: Wed, 9 Oct 2019 21:02:54 -0700
Subject: [PATCH 05/12] Clarify comment, dedupe match arms in shim.rs.
Also add a missing terminal newline to a test.
---
src/librustc/ty/instance.rs | 4 +++-
src/librustc_mir/shim.rs | 17 +++++------------
.../rfc-2091-track-caller/taking-fn-pointer.rs | 2 +-
3 files changed, 9 insertions(+), 14 deletions(-)
diff --git a/src/librustc/ty/instance.rs b/src/librustc/ty/instance.rs
index 18b625984e1a2..2b9d09b20ccfc 100644
--- a/src/librustc/ty/instance.rs
+++ b/src/librustc/ty/instance.rs
@@ -26,7 +26,9 @@ pub enum InstanceDef<'tcx> {
/// `<T as Trait>::method` where `method` receives unsizeable `self: Self`.
VtableShim(DefId),
- /// `fn()` pointer where the function is annotated with `#[track_caller]`.
+ /// `fn()` pointer where the function itself cannot be turned into a pointer.
+ ///
+ /// One example in the compiler today is functions annotated with `#[track_caller]`.
ReifyShim(DefId),
/// `<fn() as FnTrait>::call_*`
diff --git a/src/librustc_mir/shim.rs b/src/librustc_mir/shim.rs
index eced7eb09ae87..0d13daa264309 100644
--- a/src/librustc_mir/shim.rs
+++ b/src/librustc_mir/shim.rs
@@ -41,15 +41,6 @@ fn make_shim<'tcx>(tcx: TyCtxt<'tcx>, instance: ty::InstanceDef<'tcx>) -> &'tcx
None,
)
}
- ty::InstanceDef::ReifyShim(def_id) => {
- build_call_shim(
- tcx,
- def_id,
- Adjustment::Identity, // TODO(anp) is this the right kind of adjustment?
- CallKind::Direct(def_id),
- None,
- )
- }
ty::InstanceDef::FnPtrShim(def_id, ty) => {
let trait_ = tcx.trait_of_item(def_id).unwrap();
let adjustment = match tcx.lang_items().fn_trait_kind(trait_) {
@@ -75,9 +66,11 @@ fn make_shim<'tcx>(tcx: TyCtxt<'tcx>, instance: ty::InstanceDef<'tcx>) -> &'tcx
Some(arg_tys)
)
}
- ty::InstanceDef::Virtual(def_id, _) => {
- // We are generating a call back to our def-id, which the
- // codegen backend knows to turn to an actual virtual call.
+ // We are generating a call back to our def-id, which the
+ // codegen backend knows to turn to an actual virtual call.
+ ty::InstanceDef::Virtual(def_id, _) |
+ // ...or we are generating a call to the inner closure defined by #[track_caller]
+ ty::InstanceDef::ReifyShim(def_id) => {
build_call_shim(
tcx,
def_id,
diff --git a/src/test/ui/rfc-2091-track-caller/taking-fn-pointer.rs b/src/test/ui/rfc-2091-track-caller/taking-fn-pointer.rs
index df3893f2a6a19..2882d2d83ff81 100644
--- a/src/test/ui/rfc-2091-track-caller/taking-fn-pointer.rs
+++ b/src/test/ui/rfc-2091-track-caller/taking-fn-pointer.rs
@@ -13,4 +13,4 @@ fn call_it(x: fn()) {
fn main() {
call_it(f);
-}
\ No newline at end of file
+}
From ea3ecf22ae911b7e32b889b636bce86c165908c4 Mon Sep 17 00:00:00 2001
From: Adam Perry <adam.n.perry@gmail.com>
Date: Wed, 9 Oct 2019 21:13:08 -0700
Subject: [PATCH 06/12] miri calls resolve_for_fn_ptr when reifying.
---
src/librustc_mir/interpret/cast.rs | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/src/librustc_mir/interpret/cast.rs b/src/librustc_mir/interpret/cast.rs
index d120412c901a6..9ab347957f97a 100644
--- a/src/librustc_mir/interpret/cast.rs
+++ b/src/librustc_mir/interpret/cast.rs
@@ -44,7 +44,14 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
if self.tcx.has_attr(def_id, sym::rustc_args_required_const) {
bug!("reifying a fn ptr that requires const arguments");
}
- let instance = self.resolve(def_id, substs)?;
+
+ let instance = ty::Instance::resolve_for_fn_ptr(
+ *self.tcx,
+ self.param_env,
+ def_id,
+ substs,
+ ).ok_or_else(|| err_inval!(TooGeneric))?;
+
let fn_ptr = self.memory.create_fn_alloc(FnVal::Instance(instance));
self.write_scalar(Scalar::Ptr(fn_ptr.into()), dest)?;
}
From 1cdd5d099d3a8da42db6fbd259d3f757bccb961f Mon Sep 17 00:00:00 2001
From: Adam Perry <adam.n.perry@gmail.com>
Date: Thu, 10 Oct 2019 07:25:54 -0700
Subject: [PATCH 07/12] Improve docs for InstanceDef::ReifyShim.
---
src/librustc/ty/instance.rs | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/src/librustc/ty/instance.rs b/src/librustc/ty/instance.rs
index 2b9d09b20ccfc..b35b577ddf716 100644
--- a/src/librustc/ty/instance.rs
+++ b/src/librustc/ty/instance.rs
@@ -28,7 +28,10 @@ pub enum InstanceDef<'tcx> {
/// `fn()` pointer where the function itself cannot be turned into a pointer.
///
- /// One example in the compiler today is functions annotated with `#[track_caller]`.
+ /// One example in the compiler today is functions annotated with `#[track_caller]`, which
+ /// must have their implicit caller location argument populated for a call. Because this is a
+ /// required part of the function's ABI but can't be tracked as a property of the function
+ /// pointer, we create a single "caller location" at the site where the function is reified.
ReifyShim(DefId),
/// `<fn() as FnTrait>::call_*`
From 407d1d5fd4a81b2bc717fc86475209eb59d50fb8 Mon Sep 17 00:00:00 2001
From: Adam Perry <adam.n.perry@gmail.com>
Date: Thu, 10 Oct 2019 07:31:22 -0700
Subject: [PATCH 08/12] Instance::resolve_for_fn_ptr unconditionally resolves
first.
Per review feedback.
---
src/librustc/ty/instance.rs | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/src/librustc/ty/instance.rs b/src/librustc/ty/instance.rs
index b35b577ddf716..0a86b0b414802 100644
--- a/src/librustc/ty/instance.rs
+++ b/src/librustc/ty/instance.rs
@@ -310,15 +310,19 @@ impl<'tcx> Instance<'tcx> {
substs: SubstsRef<'tcx>,
) -> Option<Instance<'tcx>> {
debug!("resolve(def_id={:?}, substs={:?})", def_id, substs);
- if tcx.codegen_fn_attrs(def_id).flags.contains(CodegenFnAttrFlags::TRACK_CALLER) {
- debug!(" => fn pointer created for function with #[track_caller]");
- Some(Instance {
- def: InstanceDef::ReifyShim(def_id),
- substs,
- })
- } else {
- Instance::resolve(tcx, param_env, def_id, substs)
- }
+ Instance::resolve(tcx, param_env, def_id, substs).map(|resolved| {
+ let resolved_def = resolved.def_id();
+ let codegen_attrs = tcx.codegen_fn_attrs(resolved_def);
+ if codegen_attrs.flags.contains(CodegenFnAttrFlags::TRACK_CALLER) {
+ debug!(" => fn pointer created for function with #[track_caller]");
+ Instance {
+ def: InstanceDef::ReifyShim(resolved_def),
+ substs,
+ }
+ } else {
+ resolved
+ }
+ })
}
pub fn resolve_for_vtable(
From 2dbc62b56a1ce0457108c86156a6ab357d870f08 Mon Sep 17 00:00:00 2001
From: Adam Perry <adam.n.perry@gmail.com>
Date: Thu, 10 Oct 2019 07:50:33 -0700
Subject: [PATCH 09/12] Clarify shim implementation comment.
---
src/librustc_mir/shim.rs | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/src/librustc_mir/shim.rs b/src/librustc_mir/shim.rs
index 0d13daa264309..c4d66ee7dbd77 100644
--- a/src/librustc_mir/shim.rs
+++ b/src/librustc_mir/shim.rs
@@ -69,7 +69,8 @@ fn make_shim<'tcx>(tcx: TyCtxt<'tcx>, instance: ty::InstanceDef<'tcx>) -> &'tcx
// We are generating a call back to our def-id, which the
// codegen backend knows to turn to an actual virtual call.
ty::InstanceDef::Virtual(def_id, _) |
- // ...or we are generating a call to the inner closure defined by #[track_caller]
+ // ...or we are generating a direct call to our #[track_caller] function which
+ // requires an implicit caller location that the virtual call won't pass
ty::InstanceDef::ReifyShim(def_id) => {
build_call_shim(
tcx,
From d92cef74736aa4503e37ee67806ce5ab3a4eb97a Mon Sep 17 00:00:00 2001
From: Adam Perry <adam.n.perry@gmail.com>
Date: Fri, 11 Oct 2019 07:44:01 -0700
Subject: [PATCH 10/12] resolve_for_fn_ptr checks that the instance is an Item
before returning shim.
---
src/librustc/ty/instance.rs | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)
diff --git a/src/librustc/ty/instance.rs b/src/librustc/ty/instance.rs
index 0a86b0b414802..5139c8085a583 100644
--- a/src/librustc/ty/instance.rs
+++ b/src/librustc/ty/instance.rs
@@ -311,16 +311,18 @@ impl<'tcx> Instance<'tcx> {
) -> Option<Instance<'tcx>> {
debug!("resolve(def_id={:?}, substs={:?})", def_id, substs);
Instance::resolve(tcx, param_env, def_id, substs).map(|resolved| {
- let resolved_def = resolved.def_id();
- let codegen_attrs = tcx.codegen_fn_attrs(resolved_def);
- if codegen_attrs.flags.contains(CodegenFnAttrFlags::TRACK_CALLER) {
- debug!(" => fn pointer created for function with #[track_caller]");
- Instance {
- def: InstanceDef::ReifyShim(resolved_def),
- substs,
- }
- } else {
- resolved
+ let has_track_caller = |def| tcx.codegen_fn_attrs(def).flags
+ .contains(CodegenFnAttrFlags::TRACK_CALLER);
+
+ match resolved.def {
+ InstanceDef::Item(def_id) if has_track_caller(def_id) => {
+ debug!(" => fn pointer created for function with #[track_caller]");
+ Instance {
+ def: InstanceDef::ReifyShim(def_id),
+ substs,
+ }
+ },
+ _ => resolved,
}
})
}
From 2d5ef8f9ff091aa6e2758958745cc3edfa84f937 Mon Sep 17 00:00:00 2001
From: Adam Perry <adam.n.perry@gmail.com>
Date: Fri, 11 Oct 2019 07:45:59 -0700
Subject: [PATCH 11/12] Clarify comment about purpose of ReifyShim.
---
src/librustc_mir/shim.rs | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/src/librustc_mir/shim.rs b/src/librustc_mir/shim.rs
index c4d66ee7dbd77..f532a18072fbd 100644
--- a/src/librustc_mir/shim.rs
+++ b/src/librustc_mir/shim.rs
@@ -69,8 +69,8 @@ fn make_shim<'tcx>(tcx: TyCtxt<'tcx>, instance: ty::InstanceDef<'tcx>) -> &'tcx
// We are generating a call back to our def-id, which the
// codegen backend knows to turn to an actual virtual call.
ty::InstanceDef::Virtual(def_id, _) |
- // ...or we are generating a direct call to our #[track_caller] function which
- // requires an implicit caller location that the virtual call won't pass
+ // ...or we are generating a direct call to a function for which indirect calls must be
+ // codegen'd differently than direct ones (example: #[track_caller])
ty::InstanceDef::ReifyShim(def_id) => {
build_call_shim(
tcx,
From 19f26fafdd6e27847a155a2ba8854c8d4ff61597 Mon Sep 17 00:00:00 2001
From: Adam Perry <adam.n.perry@gmail.com>
Date: Sat, 12 Oct 2019 14:25:34 -0700
Subject: [PATCH 12/12] Remove the fn pointer #[track_caller] test.
The ICE stderr isn't normalizing correctly on some builders.
---
.../taking-fn-pointer.rs | 16 --------------
.../taking-fn-pointer.stderr | 21 -------------------
2 files changed, 37 deletions(-)
delete mode 100644 src/test/ui/rfc-2091-track-caller/taking-fn-pointer.rs
delete mode 100644 src/test/ui/rfc-2091-track-caller/taking-fn-pointer.stderr
diff --git a/src/test/ui/rfc-2091-track-caller/taking-fn-pointer.rs b/src/test/ui/rfc-2091-track-caller/taking-fn-pointer.rs
deleted file mode 100644
index 2882d2d83ff81..0000000000000
--- a/src/test/ui/rfc-2091-track-caller/taking-fn-pointer.rs
+++ /dev/null
@@ -1,16 +0,0 @@
-// failure-status: 101
-// normalize-stderr-test "note: rustc 1.* running on .*" -> "note: rustc VERSION running on TARGET"
-// normalize-stderr-test "note: compiler flags: .*" -> "note: compiler flags: FLAGS"
-
-#![feature(track_caller)] //~ WARN the feature `track_caller` is incomplete
-
-#[track_caller]
-fn f() {}
-
-fn call_it(x: fn()) {
- x();
-}
-
-fn main() {
- call_it(f);
-}
diff --git a/src/test/ui/rfc-2091-track-caller/taking-fn-pointer.stderr b/src/test/ui/rfc-2091-track-caller/taking-fn-pointer.stderr
deleted file mode 100644
index fb625ae116e7c..0000000000000
--- a/src/test/ui/rfc-2091-track-caller/taking-fn-pointer.stderr
+++ /dev/null
@@ -1,21 +0,0 @@
-warning: the feature `track_caller` is incomplete and may cause the compiler to crash
- --> $DIR/taking-fn-pointer.rs:5:12
- |
-LL | #![feature(track_caller)]
- | ^^^^^^^^^^^^
- |
- = note: `#[warn(incomplete_features)]` on by default
-
-thread 'rustc' panicked at 'index out of bounds: the len is 1 but the index is 1', $SRC_DIR/libcore/slice/mod.rs:LL:COL
-note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
-
-error: internal compiler error: unexpected panic
-
-note: the compiler unexpectedly panicked. this is a bug.
-
-note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
-
-note: rustc VERSION running on TARGET
-
-note: compiler flags: FLAGS
-