diff --git a/compiler/rustc_mir_dataflow/src/framework/cursor.rs b/compiler/rustc_mir_dataflow/src/framework/cursor.rs index fbd9376917a14..11cf8c3e89848 100644 --- a/compiler/rustc_mir_dataflow/src/framework/cursor.rs +++ b/compiler/rustc_mir_dataflow/src/framework/cursor.rs @@ -1,6 +1,7 @@ //! Random access inspection of the results of a dataflow analysis. use std::cmp::Ordering; +use std::ops::{Deref, DerefMut}; #[cfg(debug_assertions)] use rustc_index::bit_set::BitSet; @@ -8,6 +9,47 @@ use rustc_middle::mir::{self, BasicBlock, Location}; use super::{Analysis, Direction, Effect, EffectIndex, Results}; +/// Some `ResultsCursor`s want to own a `Results`, and some want to borrow a `Results`, either +/// mutable or immutably. This type allows all of the above. It's similar to `Cow`. +pub enum ResultsHandle<'a, 'tcx, A> +where + A: Analysis<'tcx>, +{ + Borrowed(&'a Results<'tcx, A>), + BorrowedMut(&'a mut Results<'tcx, A>), + Owned(Results<'tcx, A>), +} + +impl<'tcx, A> Deref for ResultsHandle<'_, 'tcx, A> +where + A: Analysis<'tcx>, +{ + type Target = Results<'tcx, A>; + + fn deref(&self) -> &Results<'tcx, A> { + match self { + ResultsHandle::Borrowed(borrowed) => borrowed, + ResultsHandle::BorrowedMut(borrowed) => borrowed, + ResultsHandle::Owned(owned) => owned, + } + } +} + +impl<'tcx, A> DerefMut for ResultsHandle<'_, 'tcx, A> +where + A: Analysis<'tcx>, +{ + fn deref_mut(&mut self) -> &mut Results<'tcx, A> { + match self { + ResultsHandle::Borrowed(_borrowed) => { + panic!("tried to deref_mut a `ResultsHandle::Borrowed") + } + ResultsHandle::BorrowedMut(borrowed) => borrowed, + ResultsHandle::Owned(owned) => owned, + } + } +} + /// Allows random access inspection of the results of a dataflow analysis. Use this when you want /// to inspect domain values only in certain locations; use `ResultsVisitor` if you want to inspect /// domain values in many or all locations. @@ -23,7 +65,7 @@ where A: Analysis<'tcx>, { body: &'mir mir::Body<'tcx>, - results: Results<'tcx, A>, + results: ResultsHandle<'mir, 'tcx, A>, state: A::Domain, pos: CursorPosition, @@ -51,13 +93,8 @@ where self.body } - /// Unwraps this cursor, returning the underlying `Results`. - pub fn into_results(self) -> Results<'tcx, A> { - self.results - } - /// Returns a new cursor that can inspect `results`. - pub fn new(body: &'mir mir::Body<'tcx>, results: Results<'tcx, A>) -> Self { + pub fn new(body: &'mir mir::Body<'tcx>, results: ResultsHandle<'mir, 'tcx, A>) -> Self { let bottom_value = results.analysis.bottom_value(body); ResultsCursor { body, diff --git a/compiler/rustc_mir_dataflow/src/framework/graphviz.rs b/compiler/rustc_mir_dataflow/src/framework/graphviz.rs index 98a4f58cb5dc3..6e4994af8b4e4 100644 --- a/compiler/rustc_mir_dataflow/src/framework/graphviz.rs +++ b/compiler/rustc_mir_dataflow/src/framework/graphviz.rs @@ -47,20 +47,16 @@ where { pub(crate) fn new( body: &'mir Body<'tcx>, - results: Results<'tcx, A>, + results: &'mir Results<'tcx, A>, style: OutputStyle, ) -> Self { let reachable = mir::traversal::reachable_as_bitset(body); - Formatter { cursor: results.into_results_cursor(body).into(), style, reachable } + Formatter { cursor: results.as_results_cursor(body).into(), style, reachable } } fn body(&self) -> &'mir Body<'tcx> { self.cursor.borrow().body() } - - pub(crate) fn into_results(self) -> Results<'tcx, A> { - self.cursor.into_inner().into_results() - } } /// A pair of a basic block and an index into that basic blocks `successors`. diff --git a/compiler/rustc_mir_dataflow/src/framework/mod.rs b/compiler/rustc_mir_dataflow/src/framework/mod.rs index 471536c23f65f..fac2e72e2411c 100644 --- a/compiler/rustc_mir_dataflow/src/framework/mod.rs +++ b/compiler/rustc_mir_dataflow/src/framework/mod.rs @@ -302,14 +302,13 @@ pub trait Analysis<'tcx> { let results = Results { analysis: self, entry_sets }; if tcx.sess.opts.unstable_opts.dump_mir_dataflow { - let (res, results) = write_graphviz_results(tcx, body, results, pass_name); + let res = write_graphviz_results(tcx, body, &results, pass_name); if let Err(e) = res { error!("Failed to write graphviz dataflow results: {}", e); } - results - } else { - results } + + results } } diff --git a/compiler/rustc_mir_dataflow/src/framework/results.rs b/compiler/rustc_mir_dataflow/src/framework/results.rs index 7c775ae7f4a56..8493a7aa44bb1 100644 --- a/compiler/rustc_mir_dataflow/src/framework/results.rs +++ b/compiler/rustc_mir_dataflow/src/framework/results.rs @@ -17,6 +17,7 @@ use super::{Analysis, ResultsCursor, ResultsVisitor, graphviz, visit_results}; use crate::errors::{ DuplicateValuesFor, PathMustEndInFilename, RequiresAnArgument, UnknownFormatter, }; +use crate::framework::cursor::ResultsHandle; pub type EntrySets<'tcx, A> = IndexVec>::Domain>; @@ -36,12 +37,30 @@ impl<'tcx, A> Results<'tcx, A> where A: Analysis<'tcx>, { - /// Creates a `ResultsCursor` that can inspect these `Results`. + /// Creates a `ResultsCursor` that can inspect these `Results`. Immutably borrows the `Results`, + /// which is appropriate when the `Results` is used outside the cursor. + pub fn as_results_cursor<'mir>( + &'mir self, + body: &'mir mir::Body<'tcx>, + ) -> ResultsCursor<'mir, 'tcx, A> { + ResultsCursor::new(body, ResultsHandle::Borrowed(self)) + } + + /// Creates a `ResultsCursor` that can mutate these `Results`. Mutably borrows the `Results`, + /// which is appropriate when the `Results` is used outside the cursor. + pub fn as_results_cursor_mut<'mir>( + &'mir mut self, + body: &'mir mir::Body<'tcx>, + ) -> ResultsCursor<'mir, 'tcx, A> { + ResultsCursor::new(body, ResultsHandle::BorrowedMut(self)) + } + + /// Creates a `ResultsCursor` that takes ownership of the `Results`. pub fn into_results_cursor<'mir>( self, body: &'mir mir::Body<'tcx>, ) -> ResultsCursor<'mir, 'tcx, A> { - ResultsCursor::new(body, self) + ResultsCursor::new(body, ResultsHandle::Owned(self)) } /// Gets the dataflow state for the given block. @@ -76,9 +95,9 @@ where pub(super) fn write_graphviz_results<'tcx, A>( tcx: TyCtxt<'tcx>, body: &mir::Body<'tcx>, - results: Results<'tcx, A>, + results: &Results<'tcx, A>, pass_name: Option<&'static str>, -) -> (std::io::Result<()>, Results<'tcx, A>) +) -> std::io::Result<()> where A: Analysis<'tcx>, A::Domain: DebugWithContext, @@ -89,7 +108,7 @@ where let def_id = body.source.def_id(); let Ok(attrs) = RustcMirAttrs::parse(tcx, def_id) else { // Invalid `rustc_mir` attrs are reported in `RustcMirAttrs::parse` - return (Ok(()), results); + return Ok(()); }; let file = try { @@ -106,12 +125,12 @@ where create_dump_file(tcx, "dot", false, A::NAME, &pass_name.unwrap_or("-----"), body)? } - _ => return (Ok(()), results), + _ => return Ok(()), } }; let mut file = match file { Ok(f) => f, - Err(e) => return (Err(e), results), + Err(e) => return Err(e), }; let style = match attrs.formatter { @@ -134,7 +153,7 @@ where file.write_all(&buf)?; }; - (lhs, graphviz.into_results()) + lhs } #[derive(Default)] diff --git a/compiler/rustc_mir_transform/src/coroutine.rs b/compiler/rustc_mir_transform/src/coroutine.rs index c2666caa1e875..db69675e100dd 100644 --- a/compiler/rustc_mir_transform/src/coroutine.rs +++ b/compiler/rustc_mir_transform/src/coroutine.rs @@ -676,12 +676,11 @@ fn locals_live_across_suspend_points<'tcx>( let mut borrowed_locals_cursor = borrowed_locals_results.clone().into_results_cursor(body); - // Calculate the MIR locals that we actually need to keep storage around - // for. - let mut requires_storage_cursor = + // Calculate the MIR locals that we need to keep storage around for. + let mut requires_storage_results = MaybeRequiresStorage::new(borrowed_locals_results.into_results_cursor(body)) - .iterate_to_fixpoint(tcx, body, None) - .into_results_cursor(body); + .iterate_to_fixpoint(tcx, body, None); + let mut requires_storage_cursor = requires_storage_results.as_results_cursor_mut(body); // Calculate the liveness of MIR locals ignoring borrows. let mut liveness = @@ -754,7 +753,7 @@ fn locals_live_across_suspend_points<'tcx>( body, &saved_locals, always_live_locals.clone(), - requires_storage_cursor.into_results(), + requires_storage_results, ); LivenessInfo {