Change InlineAsm to allow multiple targets instead

5 files changed, 54 insertions, 48 deletions

diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs
index 3017f912ef0..de18580f61a 100644
--- a/compiler/rustc_middle/src/mir/mod.rs
+++ b/compiler/rustc_middle/src/mir/mod.rs
@@ -1718,13 +1718,13 @@ mod size_asserts {
     use super::*;
     use rustc_data_structures::static_assert_size;
     // tidy-alphabetical-start
-    static_assert_size!(BasicBlockData<'_>, 136);
+    static_assert_size!(BasicBlockData<'_>, 144);
     static_assert_size!(LocalDecl<'_>, 40);
     static_assert_size!(SourceScopeData<'_>, 72);
     static_assert_size!(Statement<'_>, 32);
     static_assert_size!(StatementKind<'_>, 16);
-    static_assert_size!(Terminator<'_>, 104);
-    static_assert_size!(TerminatorKind<'_>, 88);
+    static_assert_size!(Terminator<'_>, 112);
+    static_assert_size!(TerminatorKind<'_>, 96);
     static_assert_size!(VarDebugInfo<'_>, 88);
     // tidy-alphabetical-end
 }
diff --git a/compiler/rustc_middle/src/mir/pretty.rs b/compiler/rustc_middle/src/mir/pretty.rs
index 5638b575b31..35058458eed 100644
--- a/compiler/rustc_middle/src/mir/pretty.rs
+++ b/compiler/rustc_middle/src/mir/pretty.rs
@@ -7,7 +7,7 @@ use std::path::{Path, PathBuf};
 use crate::mir::interpret::ConstAllocation;
 
 use super::graphviz::write_mir_fn_graphviz;
-use rustc_ast::InlineAsmTemplatePiece;
+use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece};
 use rustc_middle::mir::interpret::{
     alloc_range, read_target_uint, AllocBytes, AllocId, Allocation, GlobalAlloc, Pointer,
     Provenance,
@@ -868,16 +868,19 @@ impl<'tcx> TerminatorKind<'tcx> {
                 vec!["real".into(), "unwind".into()]
             }
             FalseUnwind { unwind: _, .. } => vec!["real".into()],
-            InlineAsm { destination: Some(_), unwind: UnwindAction::Cleanup(_), .. } => {
-                vec!["return".into(), "unwind".into()]
-            }
-            InlineAsm { destination: Some(_), unwind: _, .. } => {
-                vec!["return".into()]
-            }
-            InlineAsm { destination: None, unwind: UnwindAction::Cleanup(_), .. } => {
-                vec!["unwind".into()]
+            InlineAsm { options, ref targets, unwind, .. } => {
+                let mut vec = Vec::with_capacity(targets.len() + 1);
+                if !options.contains(InlineAsmOptions::NORETURN) {
+                    vec.push("return".into());
+                }
+                vec.resize(targets.len(), "label".into());
+
+                if let UnwindAction::Cleanup(_) = unwind {
+                    vec.push("unwind".into());
+                }
+
+                vec
             }
-            InlineAsm { destination: None, unwind: _, .. } => vec![],
         }
     }
 }
diff --git a/compiler/rustc_middle/src/mir/syntax.rs b/compiler/rustc_middle/src/mir/syntax.rs
index 5c9857b9c53..6f62c7186a7 100644
--- a/compiler/rustc_middle/src/mir/syntax.rs
+++ b/compiler/rustc_middle/src/mir/syntax.rs
@@ -793,9 +793,10 @@ pub enum TerminatorKind<'tcx> {
         /// used to map assembler errors back to the line in the source code.
         line_spans: &'tcx [Span],
 
-        /// Destination block after the inline assembly returns, unless it is
-        /// diverging (InlineAsmOptions::NORETURN).
-        destination: Option<BasicBlock>,
+        /// Valid targets for the inline assembly.
+        /// The first element is the fallthrough destination, unless
+        /// InlineAsmOptions::NORETURN is set.
+        targets: Vec<BasicBlock>,
 
         /// Action to be taken if the inline assembly unwinds. This is present
         /// if and only if InlineAsmOptions::MAY_UNWIND is set.
diff --git a/compiler/rustc_middle/src/mir/terminator.rs b/compiler/rustc_middle/src/mir/terminator.rs
index 381db830aea..fa4a494ff0b 100644
--- a/compiler/rustc_middle/src/mir/terminator.rs
+++ b/compiler/rustc_middle/src/mir/terminator.rs
@@ -374,8 +374,7 @@ impl<'tcx> TerminatorKind<'tcx> {
             | Yield { resume: ref t, drop: Some(u), .. }
             | Drop { target: ref t, unwind: UnwindAction::Cleanup(u), .. }
             | Assert { target: ref t, unwind: UnwindAction::Cleanup(u), .. }
-            | FalseUnwind { real_target: ref t, unwind: UnwindAction::Cleanup(u) }
-            | InlineAsm { destination: Some(ref t), unwind: UnwindAction::Cleanup(u), .. } => {
+            | FalseUnwind { real_target: ref t, unwind: UnwindAction::Cleanup(u) } => {
                 slice::from_ref(t).into_iter().copied().chain(Some(u))
             }
             Goto { target: ref t }
@@ -384,9 +383,7 @@ impl<'tcx> TerminatorKind<'tcx> {
             | Yield { resume: ref t, drop: None, .. }
             | Drop { target: ref t, unwind: _, .. }
             | Assert { target: ref t, unwind: _, .. }
-            | FalseUnwind { real_target: ref t, unwind: _ }
-            | InlineAsm { destination: None, unwind: UnwindAction::Cleanup(ref t), .. }
-            | InlineAsm { destination: Some(ref t), unwind: _, .. } => {
+            | FalseUnwind { real_target: ref t, unwind: _ } => {
                 slice::from_ref(t).into_iter().copied().chain(None)
             }
             UnwindResume
@@ -394,10 +391,11 @@ impl<'tcx> TerminatorKind<'tcx> {
             | CoroutineDrop
             | Return
             | Unreachable
-            | Call { target: None, unwind: _, .. }
-            | InlineAsm { destination: None, unwind: _, .. } => {
-                (&[]).into_iter().copied().chain(None)
+            | Call { target: None, unwind: _, .. } => (&[]).into_iter().copied().chain(None),
+            InlineAsm { ref targets, unwind: UnwindAction::Cleanup(u), .. } => {
+                targets.iter().copied().chain(Some(u))
             }
+            InlineAsm { ref targets, unwind: _, .. } => targets.iter().copied().chain(None),
             SwitchInt { ref targets, .. } => targets.targets.iter().copied().chain(None),
             FalseEdge { ref real_target, imaginary_target } => {
                 slice::from_ref(real_target).into_iter().copied().chain(Some(imaginary_target))
@@ -413,21 +411,16 @@ impl<'tcx> TerminatorKind<'tcx> {
             | Yield { resume: ref mut t, drop: Some(ref mut u), .. }
             | Drop { target: ref mut t, unwind: UnwindAction::Cleanup(ref mut u), .. }
             | Assert { target: ref mut t, unwind: UnwindAction::Cleanup(ref mut u), .. }
-            | FalseUnwind { real_target: ref mut t, unwind: UnwindAction::Cleanup(ref mut u) }
-            | InlineAsm {
-                destination: Some(ref mut t),
-                unwind: UnwindAction::Cleanup(ref mut u),
-                ..
-            } => slice::from_mut(t).into_iter().chain(Some(u)),
+            | FalseUnwind { real_target: ref mut t, unwind: UnwindAction::Cleanup(ref mut u) } => {
+                slice::from_mut(t).into_iter().chain(Some(u))
+            }
             Goto { target: ref mut t }
             | Call { target: None, unwind: UnwindAction::Cleanup(ref mut t), .. }
             | Call { target: Some(ref mut t), unwind: _, .. }
             | Yield { resume: ref mut t, drop: None, .. }
             | Drop { target: ref mut t, unwind: _, .. }
             | Assert { target: ref mut t, unwind: _, .. }
-            | FalseUnwind { real_target: ref mut t, unwind: _ }
-            | InlineAsm { destination: None, unwind: UnwindAction::Cleanup(ref mut t), .. }
-            | InlineAsm { destination: Some(ref mut t), unwind: _, .. } => {
+            | FalseUnwind { real_target: ref mut t, unwind: _ } => {
                 slice::from_mut(t).into_iter().chain(None)
             }
             UnwindResume
@@ -435,8 +428,11 @@ impl<'tcx> TerminatorKind<'tcx> {
             | CoroutineDrop
             | Return
             | Unreachable
-            | Call { target: None, unwind: _, .. }
-            | InlineAsm { destination: None, unwind: _, .. } => (&mut []).into_iter().chain(None),
+            | Call { target: None, unwind: _, .. } => (&mut []).into_iter().chain(None),
+            InlineAsm { ref mut targets, unwind: UnwindAction::Cleanup(ref mut u), .. } => {
+                targets.iter_mut().chain(Some(u))
+            }
+            InlineAsm { ref mut targets, unwind: _, .. } => targets.iter_mut().chain(None),
             SwitchInt { ref mut targets, .. } => targets.targets.iter_mut().chain(None),
             FalseEdge { ref mut real_target, ref mut imaginary_target } => {
                 slice::from_mut(real_target).into_iter().chain(Some(imaginary_target))
@@ -511,7 +507,7 @@ pub enum TerminatorEdges<'mir, 'tcx> {
     Double(BasicBlock, BasicBlock),
     /// Special action for `Yield`, `Call` and `InlineAsm` terminators.
     AssignOnReturn {
-        return_: Option<BasicBlock>,
+        return_: &'mir [BasicBlock],
         /// The cleanup block, if it exists.
         cleanup: Option<BasicBlock>,
         place: CallReturnPlaces<'mir, 'tcx>,
@@ -575,31 +571,37 @@ impl<'tcx> TerminatorKind<'tcx> {
                 TerminatorEdges::Double(real_target, imaginary_target)
             }
 
-            Yield { resume: target, drop, resume_arg, value: _ } => {
+            Yield { resume: ref target, drop, resume_arg, value: _ } => {
                 TerminatorEdges::AssignOnReturn {
-                    return_: Some(target),
+                    return_: slice::from_ref(target),
                     cleanup: drop,
                     place: CallReturnPlaces::Yield(resume_arg),
                 }
             }
 
-            Call { unwind, destination, target, func: _, args: _, fn_span: _, call_source: _ } => {
-                TerminatorEdges::AssignOnReturn {
-                    return_: target,
-                    cleanup: unwind.cleanup_block(),
-                    place: CallReturnPlaces::Call(destination),
-                }
-            }
+            Call {
+                unwind,
+                destination,
+                ref target,
+                func: _,
+                args: _,
+                fn_span: _,
+                call_source: _,
+            } => TerminatorEdges::AssignOnReturn {
+                return_: target.as_ref().map(slice::from_ref).unwrap_or_default(),
+                cleanup: unwind.cleanup_block(),
+                place: CallReturnPlaces::Call(destination),
+            },
 
             InlineAsm {
                 template: _,
                 ref operands,
                 options: _,
                 line_spans: _,
-                destination,
+                ref targets,
                 unwind,
             } => TerminatorEdges::AssignOnReturn {
-                return_: destination,
+                return_: targets,
                 cleanup: unwind.cleanup_block(),
                 place: CallReturnPlaces::InlineAsm(operands),
             },
diff --git a/compiler/rustc_middle/src/mir/visit.rs b/compiler/rustc_middle/src/mir/visit.rs
index 2c5ca82a4cd..a1418b41e05 100644
--- a/compiler/rustc_middle/src/mir/visit.rs
+++ b/compiler/rustc_middle/src/mir/visit.rs
@@ -565,7 +565,7 @@ macro_rules! make_mir_visitor {
                         operands,
                         options: _,
                         line_spans: _,
-                        destination: _,
+                        targets: _,
                         unwind: _,
                     } => {
                         for op in operands {