Skip to content

Check place iterative #61241

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
May 28, 2019
Merged

Check place iterative #61241

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
acaf284
Remove unused tcx and mir params
spastorino May 27, 2019
fb4b62b
Make check_place iterate instead of recurse
spastorino May 27, 2019
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
75 changes: 36 additions & 39 deletions src/librustc_mir/transform/qualify_min_const_fn.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -136,10 +136,10 @@ fn check_rvalue(
) -> McfResult {
match rvalue {
Rvalue::Repeat(operand, _) | Rvalue::Use(operand) => {
check_operand(tcx, mir, operand, span)
check_operand(operand, span)
}
Rvalue::Len(place) | Rvalue::Discriminant(place) | Rvalue::Ref(_, _, place) => {
check_place(tcx, mir, place, span)
check_place(place, span)
}
Rvalue::Cast(CastKind::Misc, operand, cast_ty) => {
use rustc::ty::cast::CastTy;
Expand All @@ -153,11 +153,11 @@ fn check_rvalue(
(CastTy::RPtr(_), CastTy::Float) => bug!(),
(CastTy::RPtr(_), CastTy::Int(_)) => bug!(),
(CastTy::Ptr(_), CastTy::RPtr(_)) => bug!(),
_ => check_operand(tcx, mir, operand, span),
_ => check_operand(operand, span),
}
}
Rvalue::Cast(CastKind::Pointer(PointerCast::MutToConstPointer), operand, _) => {
check_operand(tcx, mir, operand, span)
check_operand(operand, span)
}
Rvalue::Cast(CastKind::Pointer(PointerCast::UnsafeFnPointer), _, _) |
Rvalue::Cast(CastKind::Pointer(PointerCast::ClosureFnPointer(_)), _, _) |
Expand All @@ -171,8 +171,8 @@ fn check_rvalue(
)),
// binops are fine on integers
Rvalue::BinaryOp(_, lhs, rhs) | Rvalue::CheckedBinaryOp(_, lhs, rhs) => {
check_operand(tcx, mir, lhs, span)?;
check_operand(tcx, mir, rhs, span)?;
check_operand(lhs, span)?;
check_operand(rhs, span)?;
let ty = lhs.ty(mir, tcx);
if ty.is_integral() || ty.is_bool() || ty.is_char() {
Ok(())
Expand All @@ -191,7 +191,7 @@ fn check_rvalue(
Rvalue::UnaryOp(_, operand) => {
let ty = operand.ty(mir, tcx);
if ty.is_integral() || ty.is_bool() {
check_operand(tcx, mir, operand, span)
check_operand(operand, span)
} else {
Err((
span,
Expand All @@ -201,7 +201,7 @@ fn check_rvalue(
}
Rvalue::Aggregate(_, operands) => {
for operand in operands {
check_operand(tcx, mir, operand, span)?;
check_operand(operand, span)?;
}
Ok(())
}
Expand All @@ -216,11 +216,11 @@ fn check_statement(
let span = statement.source_info.span;
match &statement.kind {
StatementKind::Assign(place, rval) => {
check_place(tcx, mir, place, span)?;
check_place(place, span)?;
check_rvalue(tcx, mir, rval, span)
}

StatementKind::FakeRead(_, place) => check_place(tcx, mir, place, span),
StatementKind::FakeRead(_, place) => check_place(place, span),

// just an assignment
StatementKind::SetDiscriminant { .. } => Ok(()),
Expand All @@ -239,43 +239,40 @@ fn check_statement(
}

fn check_operand(
tcx: TyCtxt<'a, 'tcx, 'tcx>,
mir: &'a Mir<'tcx>,
operand: &Operand<'tcx>,
span: Span,
) -> McfResult {
match operand {
Operand::Move(place) | Operand::Copy(place) => {
check_place(tcx, mir, place, span)
check_place(place, span)
}
Operand::Constant(_) => Ok(()),
}
}

fn check_place(
tcx: TyCtxt<'a, 'tcx, 'tcx>,
mir: &'a Mir<'tcx>,
place: &Place<'tcx>,
span: Span,
) -> McfResult {
match place {
Place::Base(PlaceBase::Local(_)) => Ok(()),
// promoteds are always fine, they are essentially constants
Place::Base(PlaceBase::Static(box Static { kind: StaticKind::Promoted(_), .. })) => Ok(()),
Place::Base(PlaceBase::Static(box Static { kind: StaticKind::Static(_), .. })) =>
Err((span, "cannot access `static` items in const fn".into())),
Place::Projection(proj) => {
fn check_place(place: &Place<'tcx>, span: Span) -> McfResult {
place.iterate(|place_base, place_projection| {
for proj in place_projection {
match proj.elem {
| ProjectionElem::ConstantIndex { .. } | ProjectionElem::Subslice { .. }
| ProjectionElem::Deref | ProjectionElem::Field(..) | ProjectionElem::Index(_) => {
check_place(tcx, mir, &proj.base, span)
}
| ProjectionElem::Downcast(..) => {
Err((span, "`match` or `if let` in `const fn` is unstable".into()))
ProjectionElem::Downcast(..) => {
return Err((span, "`match` or `if let` in `const fn` is unstable".into()));
}
ProjectionElem::ConstantIndex { .. }
| ProjectionElem::Subslice { .. }
| ProjectionElem::Deref
| ProjectionElem::Field(..)
| ProjectionElem::Index(_) => {}
}
}
}

match place_base {
PlaceBase::Static(box Static { kind: StaticKind::Static(_), .. }) => {
Err((span, "cannot access `static` items in const fn".into()))
}
PlaceBase::Local(_)
| PlaceBase::Static(box Static { kind: StaticKind::Promoted(_), .. }) => Ok(()),
}
})
}

fn check_terminator(
Expand All @@ -290,11 +287,11 @@ fn check_terminator(
| TerminatorKind::Resume => Ok(()),

TerminatorKind::Drop { location, .. } => {
check_place(tcx, mir, location, span)
check_place(location, span)
}
TerminatorKind::DropAndReplace { location, value, .. } => {
check_place(tcx, mir, location, span)?;
check_operand(tcx, mir, value, span)
check_place(location, span)?;
check_operand(value, span)
},

TerminatorKind::FalseEdges { .. } | TerminatorKind::SwitchInt { .. } => Err((
Expand Down Expand Up @@ -346,10 +343,10 @@ fn check_terminator(
)),
}

check_operand(tcx, mir, func, span)?;
check_operand(func, span)?;

for arg in args {
check_operand(tcx, mir, arg, span)?;
check_operand(arg, span)?;
}
Ok(())
} else {
Expand All @@ -363,7 +360,7 @@ fn check_terminator(
msg: _,
target: _,
cleanup: _,
} => check_operand(tcx, mir, cond, span),
} => check_operand(cond, span),

TerminatorKind::FalseUnwind { .. } => {
Err((span, "loops are not allowed in const fn".into()))
Expand Down