rustc_mir: track inlined callees in SourceScopeData.

Author: eddyb

compiler/rustc_middle/src/mir/mod.rs

@@ -161,7 +161,7 @@ pub struct Body<'tcx> {
 
     /// A list of source scopes; these are referenced by statements
     /// and used for debuginfo. Indexed by a `SourceScope`.
-    pub source_scopes: IndexVec<SourceScope, SourceScopeData>,
+    pub source_scopes: IndexVec<SourceScope, SourceScopeData<'tcx>>,
 
     /// The yield type of the function, if it is a generator.
     pub yield_ty: Option<Ty<'tcx>>,
@@ -244,7 +244,7 @@ impl<'tcx> Body<'tcx> {
     pub fn new(
         source: MirSource<'tcx>,
         basic_blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>,
-        source_scopes: IndexVec<SourceScope, SourceScopeData>,
+        source_scopes: IndexVec<SourceScope, SourceScopeData<'tcx>>,
         local_decls: LocalDecls<'tcx>,
         user_type_annotations: ty::CanonicalUserTypeAnnotations<'tcx>,
         arg_count: usize,
@@ -1868,11 +1868,16 @@ rustc_index::newtype_index! {
     }
 }
 
-#[derive(Clone, Debug, TyEncodable, TyDecodable, HashStable)]
-pub struct SourceScopeData {
+#[derive(Clone, Debug, TyEncodable, TyDecodable, HashStable, TypeFoldable)]
+pub struct SourceScopeData<'tcx> {
     pub span: Span,
     pub parent_scope: Option<SourceScope>,
 
+    /// Whether this scope is the root of a scope tree of another body,
+    /// inlined into this body by the MIR inliner.
+    /// `ty::Instance` is the callee, and the `Span` is the call site.
+    pub inlined: Option<(ty::Instance<'tcx>, Span)>,
+
     /// Crate-local information for this source scope, that can't (and
     /// needn't) be tracked across crates.
     pub local_data: ClearCrossCrate<SourceScopeLocalData>,

compiler/rustc_middle/src/mir/type_foldable.rs

@@ -10,7 +10,6 @@ CloneTypeFoldableAndLiftImpls! {
     FakeReadCause,
     RetagKind,
     SourceScope,
-    SourceScopeData,
     SourceScopeLocalData,
     UserTypeAnnotationIndex,
 }

compiler/rustc_middle/src/mir/visit.rs

@@ -85,7 +85,7 @@ macro_rules! make_mir_visitor {
             }
 
             fn visit_source_scope_data(&mut self,
-                                           scope_data: & $($mutability)? SourceScopeData) {
+                                           scope_data: & $($mutability)? SourceScopeData<'tcx>) {
                 self.super_source_scope_data(scope_data);
             }
 
@@ -317,17 +317,46 @@ macro_rules! make_mir_visitor {
                 }
             }
 
-            fn super_source_scope_data(&mut self, scope_data: & $($mutability)? SourceScopeData) {
+            fn super_source_scope_data(
+                &mut self,
+                scope_data: & $($mutability)? SourceScopeData<'tcx>,
+            ) {
                 let SourceScopeData {
                     span,
                     parent_scope,
+                    inlined,
                     local_data: _,
                 } = scope_data;
 
                 self.visit_span(span);
                 if let Some(parent_scope) = parent_scope {
                     self.visit_source_scope(parent_scope);
                 }
+                if let Some((callee, callsite_span)) = inlined {
+                    let location = START_BLOCK.start_location();
+
+                    self.visit_span(callsite_span);
+
+                    let ty::Instance { def: callee_def, substs: callee_substs } = callee;
+                    match callee_def {
+                        ty::InstanceDef::Item(_def_id) => {}
+
+                        ty::InstanceDef::Intrinsic(_def_id) |
+                        ty::InstanceDef::VtableShim(_def_id) |
+                        ty::InstanceDef::ReifyShim(_def_id) |
+                        ty::InstanceDef::Virtual(_def_id, _) |
+                        ty::InstanceDef::ClosureOnceShim { call_once: _def_id } |
+                        ty::InstanceDef::DropGlue(_def_id, None) => {}
+
+                        ty::InstanceDef::FnPtrShim(_def_id, ty) |
+                        ty::InstanceDef::DropGlue(_def_id, Some(ty)) |
+                        ty::InstanceDef::CloneShim(_def_id, ty) => {
+                            // FIXME(eddyb) use a better `TyContext` here.
+                            self.visit_ty(ty, TyContext::Location(location));
+                        }
+                    }
+                    self.visit_substs(callee_substs, location);
+                }
             }
 
             fn super_statement(&mut self,

compiler/rustc_mir/src/shim.rs

@@ -212,7 +212,12 @@ fn new_body<'tcx>(
         source,
         basic_blocks,
         IndexVec::from_elem_n(
-            SourceScopeData { span, parent_scope: None, local_data: ClearCrossCrate::Clear },
+            SourceScopeData {
+                span,
+                parent_scope: None,
+                inlined: None,
+                local_data: ClearCrossCrate::Clear,
+            },
             1,
         ),
         local_decls,

compiler/rustc_mir/src/transform/const_prop.rs

@@ -313,7 +313,7 @@ struct ConstPropagator<'mir, 'tcx> {
     param_env: ParamEnv<'tcx>,
     // FIXME(eddyb) avoid cloning these two fields more than once,
     // by accessing them through `ecx` instead.
-    source_scopes: IndexVec<SourceScope, SourceScopeData>,
+    source_scopes: IndexVec<SourceScope, SourceScopeData<'tcx>>,
     local_decls: IndexVec<Local, LocalDecl<'tcx>>,
     // Because we have `MutVisitor` we can't obtain the `SourceInfo` from a `Location`. So we store
     // the last known `SourceInfo` here and just keep revisiting it.

compiler/rustc_mir/src/transform/inline.rs

@@ -112,7 +112,7 @@ impl Inliner<'tcx> {
 
                 let callee_body = if let Some(callee_def_id) = callsite.callee.def_id().as_local() {
                     let callee_hir_id = self.tcx.hir().local_def_id_to_hir_id(callee_def_id);
-                    // Avoid a cycle here by only using `optimized_mir` only if we have
+                    // Avoid a cycle here by only using `instance_mir` only if we have
                     // a lower `HirId` than the callee. This ensures that the callee will
                     // not inline us. This trick only works without incremental compilation.
                     // So don't do it if that is enabled. Also avoid inlining into generators,
@@ -442,15 +442,11 @@ impl Inliner<'tcx> {
                 for mut scope in callee_body.source_scopes.iter().cloned() {
                     if scope.parent_scope.is_none() {
                         scope.parent_scope = Some(callsite.source_info.scope);
-                        // FIXME(eddyb) is this really needed?
-                        // (also note that it's always overwritten below)
-                        scope.span = callee_body.span;
-                    }
 
-                    // FIXME(eddyb) this doesn't seem right at all.
-                    // The inlined source scopes should probably be annotated as
-                    // such, but also contain all of the original information.
-                    scope.span = callsite.source_info.span;
+                        // Mark the outermost callee scope as an inlined one.
+                        assert_eq!(scope.inlined, None);
+                        scope.inlined = Some((callsite.callee, callsite.source_info.span));
+                    }
 
                     let idx = caller_body.source_scopes.push(scope);
                     scope_map.push(idx);

compiler/rustc_mir/src/util/pretty.rs

@@ -548,8 +548,23 @@ fn write_scope_tree(
     };
 
     for &child in children {
-        assert_eq!(body.source_scopes[child].parent_scope, Some(parent));
-        writeln!(w, "{0:1$}scope {2} {{", "", indent, child.index())?;
+        let child_data = &body.source_scopes[child];
+        assert_eq!(child_data.parent_scope, Some(parent));
+
+        if let Some((callee, callsite_span)) = child_data.inlined {
+            let indented_header =
+                format!("{0:1$}scope {2} (inlined {3}) {{", "", indent, child.index(), callee);
+            writeln!(
+                w,
+                "{0:1$} // at {2}",
+                indented_header,
+                ALIGN,
+                tcx.sess.source_map().span_to_string(callsite_span),
+            )?;
+        } else {
+            writeln!(w, "{0:1$}scope {2} {{", "", indent, child.index())?;
+        }
+
         write_scope_tree(tcx, body, scope_tree, w, child, depth + 1)?;
         writeln!(w, "{0:1$}}}", "", depth * INDENT.len())?;
     }

compiler/rustc_mir_build/src/build/mod.rs

@@ -334,7 +334,7 @@ struct Builder<'a, 'tcx> {
 
     /// The vector of all scopes that we have created thus far;
     /// we track this for debuginfo later.
-    source_scopes: IndexVec<SourceScope, SourceScopeData>,
+    source_scopes: IndexVec<SourceScope, SourceScopeData<'tcx>>,
     source_scope: SourceScope,
 
     /// The guard-context: each time we build the guard expression for

compiler/rustc_mir_build/src/build/scope.rs

@@ -705,6 +705,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         self.source_scopes.push(SourceScopeData {
             span,
             parent_scope: Some(parent),
+            inlined: None,
             local_data: ClearCrossCrate::Set(scope_local_data),
         })
     }

src/test/mir-opt/dest-prop/cycle.main.DestinationPropagation.diff

@@ -18,7 +18,7 @@
               scope 3 {
 -                 debug z => _3;           // in scope 3 at $DIR/cycle.rs:11:9: 11:10
 +                 debug z => _4;           // in scope 3 at $DIR/cycle.rs:11:9: 11:10
-                  scope 4 {
+                  scope 4 (inlined std::mem::drop::<i32>) { // at $DIR/cycle.rs:14:5: 14:12
                       debug _x => _6;      // in scope 4 at $SRC_DIR/core/src/mem/mod.rs:LL:COL
                   }
               }

src/test/mir-opt/dest-prop/union.main.DestinationPropagation.diff

@@ -11,7 +11,7 @@
           debug un => _1;                  // in scope 1 at $DIR/union.rs:13:9: 13:11
           scope 2 {
           }
-          scope 3 {
+          scope 3 (inlined std::mem::drop::<u32>) { // at $DIR/union.rs:15:5: 15:27
               debug _x => _4;              // in scope 3 at $SRC_DIR/core/src/mem/mod.rs:LL:COL
           }
       }

src/test/mir-opt/generator_drop_cleanup.main-{closure#0}.generator_drop.0.mir

@@ -26,9 +26,9 @@ fn main::{closure#0}(_1: *mut [generator@$DIR/generator-drop-cleanup.rs:10:15: 1
     scope 1 {
         debug _s => (((*_1) as variant#3).0: std::string::String); // in scope 1 at $DIR/generator-drop-cleanup.rs:11:13: 11:15
     }
-    scope 2 {
+    scope 2 (inlined String::new) {      // at $DIR/generator-drop-cleanup.rs:11:18: 11:31
         let mut _6: std::vec::Vec<u8>;   // in scope 2 at $DIR/generator-drop-cleanup.rs:11:18: 11:31
-        scope 3 {
+        scope 3 (inlined Vec::<u8>::new) { // at $SRC_DIR/alloc/src/string.rs:LL:COL
         }
     }
 

src/test/mir-opt/inline/inline_any_operand.bar.Inline.after.mir

@@ -8,7 +8,7 @@ fn bar() -> bool {
     let mut _6: i32;                     // in scope 0 at $DIR/inline-any-operand.rs:12:5: 12:13
     scope 1 {
         debug f => _1;                   // in scope 1 at $DIR/inline-any-operand.rs:11:9: 11:10
-        scope 2 {
+        scope 2 (inlined foo) {          // at $DIR/inline-any-operand.rs:12:5: 12:13
             debug x => _5;               // in scope 2 at $DIR/inline-any-operand.rs:16:8: 16:9
             debug y => _6;               // in scope 2 at $DIR/inline-any-operand.rs:16:16: 16:17
             let mut _3: i32;             // in scope 2 at $DIR/inline-any-operand.rs:12:5: 12:13

src/test/mir-opt/inline/inline_closure.foo.Inline.after.mir

@@ -13,7 +13,7 @@ fn foo(_1: T, _2: i32) -> i32 {
     let mut _9: i32;                     // in scope 0 at $DIR/inline-closure.rs:12:5: 12:12
     scope 1 {
         debug x => _3;                   // in scope 1 at $DIR/inline-closure.rs:11:9: 11:10
-        scope 2 {
+        scope 2 (inlined foo::<T>::{closure#0}) { // at $DIR/inline-closure.rs:12:5: 12:12
             debug _t => _8;              // in scope 2 at $DIR/inline-closure.rs:11:14: 11:16
             debug _q => _9;              // in scope 2 at $DIR/inline-closure.rs:11:18: 11:20
         }

src/test/mir-opt/inline/inline_closure_borrows_arg.foo.Inline.after.mir

@@ -13,7 +13,7 @@ fn foo(_1: T, _2: &i32) -> i32 {
     let mut _10: &i32;                   // in scope 0 at $DIR/inline-closure-borrows-arg.rs:16:5: 16:12
     scope 1 {
         debug x => _3;                   // in scope 1 at $DIR/inline-closure-borrows-arg.rs:12:9: 12:10
-        scope 2 {
+        scope 2 (inlined foo::<T>::{closure#0}) { // at $DIR/inline-closure-borrows-arg.rs:16:5: 16:12
             debug r => _9;               // in scope 2 at $DIR/inline-closure-borrows-arg.rs:12:14: 12:15
             debug _s => _10;             // in scope 2 at $DIR/inline-closure-borrows-arg.rs:12:23: 12:25
             let _8: &i32;                // in scope 2 at $DIR/inline-closure-borrows-arg.rs:16:5: 16:12

src/test/mir-opt/inline/inline_closure_captures.foo.Inline.after.mir

@@ -13,7 +13,7 @@ fn foo(_1: T, _2: i32) -> (i32, T) {
     let mut _10: i32;                    // in scope 0 at $DIR/inline-closure-captures.rs:12:5: 12:9
     scope 1 {
         debug x => _3;                   // in scope 1 at $DIR/inline-closure-captures.rs:11:9: 11:10
-        scope 2 {
+        scope 2 (inlined foo::<T>::{closure#0}) { // at $DIR/inline-closure-captures.rs:12:5: 12:9
             debug _q => _10;             // in scope 2 at $DIR/inline-closure-captures.rs:11:14: 11:16
             debug q => (*((*_6).0: &i32)); // in scope 2 at $DIR/inline-closure-captures.rs:10:23: 10:24
             debug t => (*((*_6).1: &T)); // in scope 2 at $DIR/inline-closure-captures.rs:10:17: 10:18

src/test/mir-opt/inline/inline_compatibility.inlined_no_sanitize.Inline.diff

@@ -4,7 +4,7 @@
   fn inlined_no_sanitize() -> () {
       let mut _0: ();                      // return place in scope 0 at $DIR/inline-compatibility.rs:24:37: 24:37
       let _1: ();                          // in scope 0 at $DIR/inline-compatibility.rs:25:5: 25:18
-+     scope 1 {
++     scope 1 (inlined no_sanitize) {      // at $DIR/inline-compatibility.rs:25:5: 25:18
 +     }
 
       bb0: {

src/test/mir-opt/inline/inline_compatibility.inlined_target_feature.Inline.diff

@@ -4,7 +4,7 @@
   fn inlined_target_feature() -> () {
       let mut _0: ();                      // return place in scope 0 at $DIR/inline-compatibility.rs:13:40: 13:40
       let _1: ();                          // in scope 0 at $DIR/inline-compatibility.rs:14:5: 14:21
-+     scope 1 {
++     scope 1 (inlined target_feature) {   // at $DIR/inline-compatibility.rs:14:5: 14:21
 +     }
 
       bb0: {

src/test/mir-opt/inline/inline_into_box_place.main.Inline.32bit.diff

@@ -10,7 +10,7 @@
       scope 1 {
           debug _x => _1;                  // in scope 1 at $DIR/inline-into-box-place.rs:8:9: 8:11
       }
-+     scope 2 {
++     scope 2 (inlined Vec::<u32>::new) {  // at $DIR/inline-into-box-place.rs:8:33: 8:43
 +     }
 
       bb0: {

src/test/mir-opt/inline/inline_into_box_place.main.Inline.64bit.diff

@@ -10,7 +10,7 @@
       scope 1 {
           debug _x => _1;                  // in scope 1 at $DIR/inline-into-box-place.rs:8:9: 8:11
       }
-+     scope 2 {
++     scope 2 (inlined Vec::<u32>::new) {  // at $DIR/inline-into-box-place.rs:8:33: 8:43
 +     }
 
       bb0: {

src/test/mir-opt/inline/inline_retag.bar.Inline.after.mir

@@ -14,7 +14,7 @@ fn bar() -> bool {
         debug f => _1;                   // in scope 1 at $DIR/inline-retag.rs:11:9: 11:10
         let mut _9: &i32;                // in scope 1 at $DIR/inline-retag.rs:12:11: 12:14
         let mut _10: &i32;               // in scope 1 at $DIR/inline-retag.rs:12:7: 12:9
-        scope 2 {
+        scope 2 (inlined foo) {          // at $DIR/inline-retag.rs:12:5: 12:15
             debug x => _3;               // in scope 2 at $DIR/inline-retag.rs:16:8: 16:9
             debug y => _6;               // in scope 2 at $DIR/inline-retag.rs:16:17: 16:18
             let mut _11: i32;            // in scope 2 at $DIR/inline-retag.rs:12:5: 12:15

src/test/mir-opt/inline/inline_specialization.main.Inline.diff

@@ -7,7 +7,7 @@
       scope 1 {
           debug x => _1;                   // in scope 1 at $DIR/inline-specialization.rs:5:9: 5:10
       }
-+     scope 2 {
++     scope 2 (inlined <Vec<()> as Foo>::bar) { // at $DIR/inline-specialization.rs:5:13: 5:38
 +     }
 
       bb0: {

src/test/mir-opt/inline/inline_trait_method_2.test2.Inline.after.mir

@@ -5,7 +5,7 @@ fn test2(_1: &dyn X) -> bool {
     let mut _0: bool;                    // return place in scope 0 at $DIR/inline-trait-method_2.rs:4:24: 4:28
     let mut _2: &dyn X;                  // in scope 0 at $DIR/inline-trait-method_2.rs:5:10: 5:11
     let mut _3: &dyn X;                  // in scope 0 at $DIR/inline-trait-method_2.rs:5:10: 5:11
-    scope 1 {
+    scope 1 (inlined test) {             // at $DIR/inline-trait-method_2.rs:5:5: 5:12
         debug x => _2;                   // in scope 1 at $DIR/inline-trait-method_2.rs:9:9: 9:10
         let mut _4: &dyn X;              // in scope 1 at $DIR/inline-trait-method_2.rs:5:5: 5:12
     }

src/test/mir-opt/inline/issue_58867_inline_as_ref_as_mut.a.Inline.after.mir

@@ -6,7 +6,7 @@ fn a(_1: &mut [T]) -> &mut [T] {
     let mut _2: &mut [T];                // in scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:3:5: 3:15
     let mut _3: &mut [T];                // in scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:3:5: 3:15
     let mut _4: &mut [T];                // in scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:3:5: 3:6
-    scope 1 {
+    scope 1 (inlined <[T] as AsMut<[T]>>::as_mut) { // at $DIR/issue-58867-inline-as-ref-as-mut.rs:3:5: 3:15
         debug self => _4;                // in scope 1 at $SRC_DIR/core/src/convert/mod.rs:LL:COL
         let mut _5: &mut [T];            // in scope 1 at $DIR/issue-58867-inline-as-ref-as-mut.rs:3:5: 3:15
     }

src/test/mir-opt/inline/issue_58867_inline_as_ref_as_mut.b.Inline.after.mir

@@ -6,7 +6,7 @@ fn b(_1: &mut Box<T>) -> &mut T {
     let mut _2: &mut T;                  // in scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:8:5: 8:15
     let mut _3: &mut T;                  // in scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:8:5: 8:15
     let mut _4: &mut std::boxed::Box<T>; // in scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:8:5: 8:6
-    scope 1 {
+    scope 1 (inlined <Box<T> as AsMut<T>>::as_mut) { // at $DIR/issue-58867-inline-as-ref-as-mut.rs:8:5: 8:15
         debug self => _4;                // in scope 1 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
         let mut _5: &mut T;              // in scope 1 at $DIR/issue-58867-inline-as-ref-as-mut.rs:8:5: 8:15
         let mut _6: &mut T;              // in scope 1 at $DIR/issue-58867-inline-as-ref-as-mut.rs:8:5: 8:15

src/test/mir-opt/inline/issue_58867_inline_as_ref_as_mut.c.Inline.after.mir

@@ -5,7 +5,7 @@ fn c(_1: &[T]) -> &[T] {
     let mut _0: &[T];                    // return place in scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:12:25: 12:29
     let _2: &[T];                        // in scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:13:5: 13:15
     let mut _3: &[T];                    // in scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:13:5: 13:6
-    scope 1 {
+    scope 1 (inlined <[T] as AsRef<[T]>>::as_ref) { // at $DIR/issue-58867-inline-as-ref-as-mut.rs:13:5: 13:15
         debug self => _3;                // in scope 1 at $SRC_DIR/core/src/convert/mod.rs:LL:COL
     }
 

src/test/mir-opt/inline/issue_58867_inline_as_ref_as_mut.d.Inline.after.mir

@@ -5,7 +5,7 @@ fn d(_1: &Box<T>) -> &T {
     let mut _0: &T;                      // return place in scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:17:28: 17:30
     let _2: &T;                          // in scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:18:5: 18:15
     let mut _3: &std::boxed::Box<T>;     // in scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:18:5: 18:6
-    scope 1 {
+    scope 1 (inlined <Box<T> as AsRef<T>>::as_ref) { // at $DIR/issue-58867-inline-as-ref-as-mut.rs:18:5: 18:15
         debug self => _3;                // in scope 1 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
     }