Auto merge of #88439 - cynecx:unwind_asm, r=Amanieu

Unwinding support for inline assembly

r? `@Amanieu`

4 files changed, 110 insertions, 31 deletions

diff --git a/compiler/rustc_mir_dataflow/src/framework/direction.rs b/compiler/rustc_mir_dataflow/src/framework/direction.rs
index 8a9ced91eb3..6131ee79818 100644
--- a/compiler/rustc_mir_dataflow/src/framework/direction.rs
+++ b/compiler/rustc_mir_dataflow/src/framework/direction.rs
@@ -4,7 +4,9 @@ use rustc_middle::ty::TyCtxt;
 use std::ops::RangeInclusive;
 
 use super::visitor::{ResultsVisitable, ResultsVisitor};
-use super::{Analysis, Effect, EffectIndex, GenKillAnalysis, GenKillSet, SwitchIntTarget};
+use super::{
+    Analysis, CallReturnPlaces, Effect, EffectIndex, GenKillAnalysis, GenKillSet, SwitchIntTarget,
+};
 
 pub trait Direction {
     fn is_forward() -> bool;
@@ -235,14 +237,26 @@ impl Direction for Backward {
                 // Apply terminator-specific edge effects.
                 //
                 // FIXME(ecstaticmorse): Avoid cloning the exit state unconditionally.
-                mir::TerminatorKind::Call {
-                    destination: Some((return_place, dest)),
-                    ref func,
-                    ref args,
-                    ..
+                mir::TerminatorKind::Call { destination: Some((return_place, dest)), .. }
+                    if dest == bb =>
+                {
+                    let mut tmp = exit_state.clone();
+                    analysis.apply_call_return_effect(
+                        &mut tmp,
+                        pred,
+                        CallReturnPlaces::Call(return_place),
+                    );
+                    propagate(pred, &tmp);
+                }
+                mir::TerminatorKind::InlineAsm {
+                    destination: Some(dest), ref operands, ..
                 } if dest == bb => {
                     let mut tmp = exit_state.clone();
-                    analysis.apply_call_return_effect(&mut tmp, pred, func, args, return_place);
+                    analysis.apply_call_return_effect(
+                        &mut tmp,
+                        pred,
+                        CallReturnPlaces::InlineAsm(operands),
+                    );
                     propagate(pred, &tmp);
                 }
 
@@ -258,6 +272,7 @@ impl Direction for Backward {
                 | mir::TerminatorKind::Drop { unwind: Some(unwind), .. }
                 | mir::TerminatorKind::DropAndReplace { unwind: Some(unwind), .. }
                 | mir::TerminatorKind::FalseUnwind { unwind: Some(unwind), .. }
+                | mir::TerminatorKind::InlineAsm { cleanup: Some(unwind), .. }
                     if unwind == bb =>
                 {
                     if dead_unwinds.map_or(true, |dead| !dead.contains(bb)) {
@@ -467,7 +482,7 @@ impl Direction for Forward {
                 propagate(target, exit_state);
             }
 
-            Call { cleanup, destination, ref func, ref args, from_hir_call: _, fn_span: _ } => {
+            Call { cleanup, destination, func: _, args: _, from_hir_call: _, fn_span: _ } => {
                 if let Some(unwind) = cleanup {
                     if dead_unwinds.map_or(true, |dead| !dead.contains(bb)) {
                         propagate(unwind, exit_state);
@@ -477,13 +492,37 @@ impl Direction for Forward {
                 if let Some((dest_place, target)) = destination {
                     // N.B.: This must be done *last*, otherwise the unwind path will see the call
                     // return effect.
-                    analysis.apply_call_return_effect(exit_state, bb, func, args, dest_place);
+                    analysis.apply_call_return_effect(
+                        exit_state,
+                        bb,
+                        CallReturnPlaces::Call(dest_place),
+                    );
                     propagate(target, exit_state);
                 }
             }
 
-            InlineAsm { template: _, operands: _, options: _, line_spans: _, destination } => {
+            InlineAsm {
+                template: _,
+                ref operands,
+                options: _,
+                line_spans: _,
+                destination,
+                cleanup,
+            } => {
+                if let Some(unwind) = cleanup {
+                    if dead_unwinds.map_or(true, |dead| !dead.contains(bb)) {
+                        propagate(unwind, exit_state);
+                    }
+                }
+
                 if let Some(target) = destination {
+                    // N.B.: This must be done *last*, otherwise the unwind path will see the call
+                    // return effect.
+                    analysis.apply_call_return_effect(
+                        exit_state,
+                        bb,
+                        CallReturnPlaces::InlineAsm(operands),
+                    );
                     propagate(target, exit_state);
                 }
             }
diff --git a/compiler/rustc_mir_dataflow/src/framework/graphviz.rs b/compiler/rustc_mir_dataflow/src/framework/graphviz.rs
index a370f8e40f9..517bc086ef6 100644
--- a/compiler/rustc_mir_dataflow/src/framework/graphviz.rs
+++ b/compiler/rustc_mir_dataflow/src/framework/graphviz.rs
@@ -10,7 +10,7 @@ use rustc_middle::mir::graphviz_safe_def_name;
 use rustc_middle::mir::{self, BasicBlock, Body, Location};
 
 use super::fmt::{DebugDiffWithAdapter, DebugWithAdapter, DebugWithContext};
-use super::{Analysis, Direction, Results, ResultsRefCursor, ResultsVisitor};
+use super::{Analysis, CallReturnPlaces, Direction, Results, ResultsRefCursor, ResultsVisitor};
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum OutputStyle {
@@ -231,16 +231,15 @@ where
         // for the basic block itself. That way, we could display terminator-specific effects for
         // backward dataflow analyses as well as effects for `SwitchInt` terminators.
         match terminator.kind {
-            mir::TerminatorKind::Call {
-                destination: Some((return_place, _)),
-                ref func,
-                ref args,
-                ..
-            } => {
+            mir::TerminatorKind::Call { destination: Some((return_place, _)), .. } => {
                 self.write_row(w, "", "(on successful return)", |this, w, fmt| {
                     let state_on_unwind = this.results.get().clone();
                     this.results.apply_custom_effect(|analysis, state| {
-                        analysis.apply_call_return_effect(state, block, func, args, return_place);
+                        analysis.apply_call_return_effect(
+                            state,
+                            block,
+                            CallReturnPlaces::Call(return_place),
+                        );
                     });
 
                     write!(
@@ -278,6 +277,31 @@ where
                 })?;
             }
 
+            mir::TerminatorKind::InlineAsm { destination: Some(_), ref operands, .. } => {
+                self.write_row(w, "", "(on successful return)", |this, w, fmt| {
+                    let state_on_unwind = this.results.get().clone();
+                    this.results.apply_custom_effect(|analysis, state| {
+                        analysis.apply_call_return_effect(
+                            state,
+                            block,
+                            CallReturnPlaces::InlineAsm(operands),
+                        );
+                    });
+
+                    write!(
+                        w,
+                        r#"<td balign="left" colspan="{colspan}" {fmt} align="left">{diff}</td>"#,
+                        colspan = this.style.num_state_columns(),
+                        fmt = fmt,
+                        diff = diff_pretty(
+                            this.results.get(),
+                            &state_on_unwind,
+                            this.results.analysis()
+                        ),
+                    )
+                })?;
+            }
+
             _ => {}
         };
 
diff --git a/compiler/rustc_mir_dataflow/src/framework/mod.rs b/compiler/rustc_mir_dataflow/src/framework/mod.rs
index f0c9ac4c504..500fba8b114 100644
--- a/compiler/rustc_mir_dataflow/src/framework/mod.rs
+++ b/compiler/rustc_mir_dataflow/src/framework/mod.rs
@@ -160,9 +160,7 @@ pub trait Analysis<'tcx>: AnalysisDomain<'tcx> {
         &self,
         state: &mut Self::Domain,
         block: BasicBlock,
-        func: &mir::Operand<'tcx>,
-        args: &[mir::Operand<'tcx>],
-        return_place: mir::Place<'tcx>,
+        return_places: CallReturnPlaces<'_, 'tcx>,
     );
 
     /// Updates the current dataflow state with the effect of resuming from a `Yield` terminator.
@@ -276,9 +274,7 @@ pub trait GenKillAnalysis<'tcx>: Analysis<'tcx> {
         &self,
         trans: &mut impl GenKill<Self::Idx>,
         block: BasicBlock,
-        func: &mir::Operand<'tcx>,
-        args: &[mir::Operand<'tcx>],
-        return_place: mir::Place<'tcx>,
+        return_places: CallReturnPlaces<'_, 'tcx>,
     );
 
     /// See `Analysis::apply_yield_resume_effect`.
@@ -347,11 +343,9 @@ where
         &self,
         state: &mut A::Domain,
         block: BasicBlock,
-        func: &mir::Operand<'tcx>,
-        args: &[mir::Operand<'tcx>],
-        return_place: mir::Place<'tcx>,
+        return_places: CallReturnPlaces<'_, 'tcx>,
     ) {
-        self.call_return_effect(state, block, func, args, return_place);
+        self.call_return_effect(state, block, return_places);
     }
 
     fn apply_yield_resume_effect(
@@ -542,5 +536,29 @@ pub trait SwitchIntEdgeEffects<D> {
     fn apply(&mut self, apply_edge_effect: impl FnMut(&mut D, SwitchIntTarget));
 }
 
+/// List of places that are written to after a successful (non-unwind) return
+/// from a `Call` or `InlineAsm`.
+pub enum CallReturnPlaces<'a, 'tcx> {
+    Call(mir::Place<'tcx>),
+    InlineAsm(&'a [mir::InlineAsmOperand<'tcx>]),
+}
+
+impl<'tcx> CallReturnPlaces<'_, 'tcx> {
+    pub fn for_each(&self, mut f: impl FnMut(mir::Place<'tcx>)) {
+        match *self {
+            Self::Call(place) => f(place),
+            Self::InlineAsm(operands) => {
+                for op in operands {
+                    match *op {
+                        mir::InlineAsmOperand::Out { place: Some(place), .. }
+                        | mir::InlineAsmOperand::InOut { out_place: Some(place), .. } => f(place),
+                        _ => {}
+                    }
+                }
+            }
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests;
diff --git a/compiler/rustc_mir_dataflow/src/framework/tests.rs b/compiler/rustc_mir_dataflow/src/framework/tests.rs
index 6efa8daec48..01ca8ca9258 100644
--- a/compiler/rustc_mir_dataflow/src/framework/tests.rs
+++ b/compiler/rustc_mir_dataflow/src/framework/tests.rs
@@ -220,9 +220,7 @@ impl<D: Direction> Analysis<'tcx> for MockAnalysis<'tcx, D> {
         &self,
         _state: &mut Self::Domain,
         _block: BasicBlock,
-        _func: &mir::Operand<'tcx>,
-        _args: &[mir::Operand<'tcx>],
-        _return_place: mir::Place<'tcx>,
+        _return_places: CallReturnPlaces<'_, 'tcx>,
     ) {
     }
 }