diff options
Diffstat (limited to 'compiler/rustc_const_eval/src/interpret/intrinsics')
| -rw-r--r-- | compiler/rustc_const_eval/src/interpret/intrinsics/caller_location.rs | 130 | ||||
| -rw-r--r-- | compiler/rustc_const_eval/src/interpret/intrinsics/type_name.rs | 196 |
2 files changed, 326 insertions, 0 deletions
diff --git a/compiler/rustc_const_eval/src/interpret/intrinsics/caller_location.rs b/compiler/rustc_const_eval/src/interpret/intrinsics/caller_location.rs new file mode 100644 index 000000000..5864b9215 --- /dev/null +++ b/compiler/rustc_const_eval/src/interpret/intrinsics/caller_location.rs @@ -0,0 +1,130 @@ +use std::convert::TryFrom; + +use rustc_ast::Mutability; +use rustc_hir::lang_items::LangItem; +use rustc_middle::mir::TerminatorKind; +use rustc_middle::ty::layout::LayoutOf; +use rustc_middle::ty::subst::Subst; +use rustc_span::{Span, Symbol}; + +use crate::interpret::{ + intrinsics::{InterpCx, Machine}, + MPlaceTy, MemoryKind, Scalar, +}; + +impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { + /// Walks up the callstack from the intrinsic's callsite, searching for the first callsite in a + /// frame which is not `#[track_caller]`. + pub(crate) fn find_closest_untracked_caller_location(&self) -> Span { + for frame in self.stack().iter().rev() { + debug!("find_closest_untracked_caller_location: checking frame {:?}", frame.instance); + + // Assert that the frame we look at is actually executing code currently + // (`loc` is `Err` when we are unwinding and the frame does not require cleanup). + let loc = frame.loc.unwrap(); + + // This could be a non-`Call` terminator (such as `Drop`), or not a terminator at all + // (such as `box`). Use the normal span by default. + let mut source_info = *frame.body.source_info(loc); + + // If this is a `Call` terminator, use the `fn_span` instead. + let block = &frame.body.basic_blocks()[loc.block]; + if loc.statement_index == block.statements.len() { + debug!( + "find_closest_untracked_caller_location: got terminator {:?} ({:?})", + block.terminator(), + block.terminator().kind + ); + if let TerminatorKind::Call { fn_span, .. } = block.terminator().kind { + source_info.span = fn_span; + } + } + + // Walk up the `SourceScope`s, in case some of them are from MIR inlining. + // If so, the starting `source_info.span` is in the innermost inlined + // function, and will be replaced with outer callsite spans as long + // as the inlined functions were `#[track_caller]`. + loop { + let scope_data = &frame.body.source_scopes[source_info.scope]; + + if let Some((callee, callsite_span)) = scope_data.inlined { + // Stop inside the most nested non-`#[track_caller]` function, + // before ever reaching its caller (which is irrelevant). + if !callee.def.requires_caller_location(*self.tcx) { + return source_info.span; + } + source_info.span = callsite_span; + } + + // Skip past all of the parents with `inlined: None`. + match scope_data.inlined_parent_scope { + Some(parent) => source_info.scope = parent, + None => break, + } + } + + // Stop inside the most nested non-`#[track_caller]` function, + // before ever reaching its caller (which is irrelevant). + if !frame.instance.def.requires_caller_location(*self.tcx) { + return source_info.span; + } + } + + span_bug!(self.cur_span(), "no non-`#[track_caller]` frame found") + } + + /// Allocate a `const core::panic::Location` with the provided filename and line/column numbers. + pub(crate) fn alloc_caller_location( + &mut self, + filename: Symbol, + line: u32, + col: u32, + ) -> MPlaceTy<'tcx, M::Provenance> { + let loc_details = &self.tcx.sess.opts.unstable_opts.location_detail; + let file = if loc_details.file { + self.allocate_str(filename.as_str(), MemoryKind::CallerLocation, Mutability::Not) + } else { + // FIXME: This creates a new allocation each time. It might be preferable to + // perform this allocation only once, and re-use the `MPlaceTy`. + // See https://github.com/rust-lang/rust/pull/89920#discussion_r730012398 + self.allocate_str("<redacted>", MemoryKind::CallerLocation, Mutability::Not) + }; + let line = if loc_details.line { Scalar::from_u32(line) } else { Scalar::from_u32(0) }; + let col = if loc_details.column { Scalar::from_u32(col) } else { Scalar::from_u32(0) }; + + // Allocate memory for `CallerLocation` struct. + let loc_ty = self + .tcx + .bound_type_of(self.tcx.require_lang_item(LangItem::PanicLocation, None)) + .subst(*self.tcx, self.tcx.mk_substs([self.tcx.lifetimes.re_erased.into()].iter())); + let loc_layout = self.layout_of(loc_ty).unwrap(); + // This can fail if rustc runs out of memory right here. Trying to emit an error would be + // pointless, since that would require allocating more memory than a Location. + let location = self.allocate(loc_layout, MemoryKind::CallerLocation).unwrap(); + + // Initialize fields. + self.write_immediate(file.to_ref(self), &self.mplace_field(&location, 0).unwrap().into()) + .expect("writing to memory we just allocated cannot fail"); + self.write_scalar(line, &self.mplace_field(&location, 1).unwrap().into()) + .expect("writing to memory we just allocated cannot fail"); + self.write_scalar(col, &self.mplace_field(&location, 2).unwrap().into()) + .expect("writing to memory we just allocated cannot fail"); + + location + } + + pub(crate) fn location_triple_for_span(&self, span: Span) -> (Symbol, u32, u32) { + let topmost = span.ctxt().outer_expn().expansion_cause().unwrap_or(span); + let caller = self.tcx.sess.source_map().lookup_char_pos(topmost.lo()); + ( + Symbol::intern(&caller.file.name.prefer_remapped().to_string_lossy()), + u32::try_from(caller.line).unwrap(), + u32::try_from(caller.col_display).unwrap().checked_add(1).unwrap(), + ) + } + + pub fn alloc_caller_location_for_span(&mut self, span: Span) -> MPlaceTy<'tcx, M::Provenance> { + let (file, line, column) = self.location_triple_for_span(span); + self.alloc_caller_location(file, line, column) + } +} diff --git a/compiler/rustc_const_eval/src/interpret/intrinsics/type_name.rs b/compiler/rustc_const_eval/src/interpret/intrinsics/type_name.rs new file mode 100644 index 000000000..f9847742f --- /dev/null +++ b/compiler/rustc_const_eval/src/interpret/intrinsics/type_name.rs @@ -0,0 +1,196 @@ +use rustc_data_structures::intern::Interned; +use rustc_hir::def_id::CrateNum; +use rustc_hir::definitions::DisambiguatedDefPathData; +use rustc_middle::mir::interpret::{Allocation, ConstAllocation}; +use rustc_middle::ty::{ + self, + print::{PrettyPrinter, Print, Printer}, + subst::{GenericArg, GenericArgKind}, + Ty, TyCtxt, +}; +use std::fmt::Write; + +struct AbsolutePathPrinter<'tcx> { + tcx: TyCtxt<'tcx>, + path: String, +} + +impl<'tcx> Printer<'tcx> for AbsolutePathPrinter<'tcx> { + type Error = std::fmt::Error; + + type Path = Self; + type Region = Self; + type Type = Self; + type DynExistential = Self; + type Const = Self; + + fn tcx(&self) -> TyCtxt<'tcx> { + self.tcx + } + + fn print_region(self, _region: ty::Region<'_>) -> Result<Self::Region, Self::Error> { + Ok(self) + } + + fn print_type(mut self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error> { + match *ty.kind() { + // Types without identity. + ty::Bool + | ty::Char + | ty::Int(_) + | ty::Uint(_) + | ty::Float(_) + | ty::Str + | ty::Array(_, _) + | ty::Slice(_) + | ty::RawPtr(_) + | ty::Ref(_, _, _) + | ty::FnPtr(_) + | ty::Never + | ty::Tuple(_) + | ty::Dynamic(_, _) => self.pretty_print_type(ty), + + // Placeholders (all printed as `_` to uniformize them). + ty::Param(_) | ty::Bound(..) | ty::Placeholder(_) | ty::Infer(_) | ty::Error(_) => { + write!(self, "_")?; + Ok(self) + } + + // Types with identity (print the module path). + ty::Adt(ty::AdtDef(Interned(&ty::AdtDefData { did: def_id, .. }, _)), substs) + | ty::FnDef(def_id, substs) + | ty::Opaque(def_id, substs) + | ty::Projection(ty::ProjectionTy { item_def_id: def_id, substs }) + | ty::Closure(def_id, substs) + | ty::Generator(def_id, substs, _) => self.print_def_path(def_id, substs), + ty::Foreign(def_id) => self.print_def_path(def_id, &[]), + + ty::GeneratorWitness(_) => bug!("type_name: unexpected `GeneratorWitness`"), + } + } + + fn print_const(self, ct: ty::Const<'tcx>) -> Result<Self::Const, Self::Error> { + self.pretty_print_const(ct, false) + } + + fn print_dyn_existential( + mut self, + predicates: &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>, + ) -> Result<Self::DynExistential, Self::Error> { + let mut first = true; + for p in predicates { + if !first { + write!(self, "+")?; + } + first = false; + self = p.print(self)?; + } + Ok(self) + } + + fn path_crate(mut self, cnum: CrateNum) -> Result<Self::Path, Self::Error> { + self.path.push_str(self.tcx.crate_name(cnum).as_str()); + Ok(self) + } + + fn path_qualified( + self, + self_ty: Ty<'tcx>, + trait_ref: Option<ty::TraitRef<'tcx>>, + ) -> Result<Self::Path, Self::Error> { + self.pretty_path_qualified(self_ty, trait_ref) + } + + fn path_append_impl( + self, + print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>, + _disambiguated_data: &DisambiguatedDefPathData, + self_ty: Ty<'tcx>, + trait_ref: Option<ty::TraitRef<'tcx>>, + ) -> Result<Self::Path, Self::Error> { + self.pretty_path_append_impl( + |mut cx| { + cx = print_prefix(cx)?; + + cx.path.push_str("::"); + + Ok(cx) + }, + self_ty, + trait_ref, + ) + } + + fn path_append( + mut self, + print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>, + disambiguated_data: &DisambiguatedDefPathData, + ) -> Result<Self::Path, Self::Error> { + self = print_prefix(self)?; + + write!(self.path, "::{}", disambiguated_data.data).unwrap(); + + Ok(self) + } + + fn path_generic_args( + mut self, + print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>, + args: &[GenericArg<'tcx>], + ) -> Result<Self::Path, Self::Error> { + self = print_prefix(self)?; + let args = + args.iter().cloned().filter(|arg| !matches!(arg.unpack(), GenericArgKind::Lifetime(_))); + if args.clone().next().is_some() { + self.generic_delimiters(|cx| cx.comma_sep(args)) + } else { + Ok(self) + } + } +} + +impl<'tcx> PrettyPrinter<'tcx> for AbsolutePathPrinter<'tcx> { + fn should_print_region(&self, _region: ty::Region<'_>) -> bool { + false + } + fn comma_sep<T>(mut self, mut elems: impl Iterator<Item = T>) -> Result<Self, Self::Error> + where + T: Print<'tcx, Self, Output = Self, Error = Self::Error>, + { + if let Some(first) = elems.next() { + self = first.print(self)?; + for elem in elems { + self.path.push_str(", "); + self = elem.print(self)?; + } + } + Ok(self) + } + + fn generic_delimiters( + mut self, + f: impl FnOnce(Self) -> Result<Self, Self::Error>, + ) -> Result<Self, Self::Error> { + write!(self, "<")?; + + self = f(self)?; + + write!(self, ">")?; + + Ok(self) + } +} + +impl Write for AbsolutePathPrinter<'_> { + fn write_str(&mut self, s: &str) -> std::fmt::Result { + self.path.push_str(s); + Ok(()) + } +} + +/// Directly returns an `Allocation` containing an absolute path representation of the given type. +pub(crate) fn alloc_type_name<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> ConstAllocation<'tcx> { + let path = AbsolutePathPrinter { tcx, path: String::new() }.print_type(ty).unwrap().path; + let alloc = Allocation::from_bytes_byte_aligned_immutable(path.into_bytes()); + tcx.intern_const_alloc(alloc) +} |